| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Dave Airlie | 13315 | 53.78% | 15 | 9.74% |
| Stephen Chandler Paul | 6626 | 26.76% | 46 | 29.87% |
| Ville Syrjälä | 1207 | 4.87% | 13 | 8.44% |
| Dhinakaran Pandiyan | 606 | 2.45% | 6 | 3.90% |
| Mikita Lipski | 576 | 2.33% | 7 | 4.55% |
| David Francis | 448 | 1.81% | 4 | 2.60% |
| Mykola Lysenko | 438 | 1.77% | 5 | 3.25% |
| Wayne Lin | 346 | 1.40% | 5 | 3.25% |
| Sean Paul | 185 | 0.75% | 3 | 1.95% |
| Benjamin Gaignard | 142 | 0.57% | 2 | 1.30% |
| Libin Yang | 141 | 0.57% | 1 | 0.65% |
| Imre Deak | 118 | 0.48% | 4 | 2.60% |
| Jim Bride | 112 | 0.45% | 1 | 0.65% |
| Daniel Vetter | 111 | 0.45% | 8 | 5.19% |
| Hersen Wu | 78 | 0.32% | 1 | 0.65% |
| Pankaj Bharadiya | 50 | 0.20% | 2 | 1.30% |
| Chris Wilson | 37 | 0.15% | 3 | 1.95% |
| Harry Wentland | 26 | 0.11% | 2 | 1.30% |
| Andrey Grodzovsky | 22 | 0.09% | 1 | 0.65% |
| Joe Perches | 21 | 0.08% | 1 | 0.65% |
| Rickard Strandqvist | 18 | 0.07% | 1 | 0.65% |
| Jani Nikula | 18 | 0.07% | 2 | 1.30% |
| Damien Lespiau | 16 | 0.06% | 2 | 1.30% |
| Maarten Lankhorst | 13 | 0.05% | 1 | 0.65% |
| Colin Ian King | 12 | 0.05% | 1 | 0.65% |
| Adam J. Richter | 11 | 0.04% | 1 | 0.65% |
| José Roberto de Souza | 10 | 0.04% | 3 | 1.95% |
| Dingchen Zhang | 9 | 0.04% | 1 | 0.65% |
| Stanislav Lisovskiy | 8 | 0.03% | 1 | 0.65% |
| Matt Roper | 8 | 0.03% | 1 | 0.65% |
| Andy Shevchenko | 7 | 0.03% | 1 | 0.65% |
| Joe Moriarty | 5 | 0.02% | 1 | 0.65% |
| Thierry Reding | 4 | 0.02% | 1 | 0.65% |
| Insu Yun | 4 | 0.02% | 1 | 0.65% |
| Rob Clark | 3 | 0.01% | 1 | 0.65% |
| Hans Verkuil | 3 | 0.01% | 1 | 0.65% |
| Manasi D Navare | 2 | 0.01% | 1 | 0.65% |
| Chenwandun | 1 | 0.00% | 1 | 0.65% |
| Alex Deucher | 1 | 0.00% | 1 | 0.65% |
| Wambui Karuga | 1 | 0.00% | 1 | 0.65% |
| Total | 24759 | 154 |
/* * Copyright © 2014 Red Hat * * Permission to use, copy, modify, distribute, and sell this software and its * documentation for any purpose is hereby granted without fee, provided that * the above copyright notice appear in all copies and that both that copyright * notice and this permission notice appear in supporting documentation, and * that the name of the copyright holders not be used in advertising or * publicity pertaining to distribution of the software without specific, * written prior permission. The copyright holders make no representations * about the suitability of this software for any purpose. It is provided "as * is" without express or implied warranty. * * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE * OF THIS SOFTWARE. */ #include <linux/delay.h> #include <linux/errno.h> #include <linux/i2c.h> #include <linux/init.h> #include <linux/kernel.h> #include <linux/sched.h> #include <linux/seq_file.h> #if IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS) #include <linux/stacktrace.h> #include <linux/sort.h> #include <linux/timekeeping.h> #include <linux/math64.h> #endif #include <drm/drm_atomic.h> #include <drm/drm_atomic_helper.h> #include <drm/drm_dp_mst_helper.h> #include <drm/drm_drv.h> #include <drm/drm_print.h> #include <drm/drm_probe_helper.h> #include "drm_crtc_helper_internal.h" #include "drm_dp_mst_topology_internal.h" /** * DOC: dp mst helper * * These functions contain parts of the DisplayPort 1.2a MultiStream Transport * protocol. The helpers contain a topology manager and bandwidth manager. * The helpers encapsulate the sending and received of sideband msgs. */ struct drm_dp_pending_up_req { struct drm_dp_sideband_msg_hdr hdr; struct drm_dp_sideband_msg_req_body msg; struct list_head next; }; static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr, char *buf); static void drm_dp_mst_topology_put_port(struct drm_dp_mst_port *port); static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr, int id, struct drm_dp_payload *payload); static int drm_dp_send_dpcd_read(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port, int offset, int size, u8 *bytes); static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port, int offset, int size, u8 *bytes); static int drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_branch *mstb); static void drm_dp_send_clear_payload_id_table(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_branch *mstb); static int drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_branch *mstb, struct drm_dp_mst_port *port); static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr, u8 *guid); static int drm_dp_mst_register_i2c_bus(struct drm_dp_aux *aux); static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_aux *aux); static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr); #define DBG_PREFIX "[dp_mst]" #define DP_STR(x) [DP_ ## x] = #x static const char *drm_dp_mst_req_type_str(u8 req_type) { static const char * const req_type_str[] = { DP_STR(GET_MSG_TRANSACTION_VERSION), DP_STR(LINK_ADDRESS), DP_STR(CONNECTION_STATUS_NOTIFY), DP_STR(ENUM_PATH_RESOURCES), DP_STR(ALLOCATE_PAYLOAD), DP_STR(QUERY_PAYLOAD), DP_STR(RESOURCE_STATUS_NOTIFY), DP_STR(CLEAR_PAYLOAD_ID_TABLE), DP_STR(REMOTE_DPCD_READ), DP_STR(REMOTE_DPCD_WRITE), DP_STR(REMOTE_I2C_READ), DP_STR(REMOTE_I2C_WRITE), DP_STR(POWER_UP_PHY), DP_STR(POWER_DOWN_PHY), DP_STR(SINK_EVENT_NOTIFY), DP_STR(QUERY_STREAM_ENC_STATUS), }; if (req_type >= ARRAY_SIZE(req_type_str) || !req_type_str[req_type]) return "unknown"; return req_type_str[req_type]; } #undef DP_STR #define DP_STR(x) [DP_NAK_ ## x] = #x static const char *drm_dp_mst_nak_reason_str(u8 nak_reason) { static const char * const nak_reason_str[] = { DP_STR(WRITE_FAILURE), DP_STR(INVALID_READ), DP_STR(CRC_FAILURE), DP_STR(BAD_PARAM), DP_STR(DEFER), DP_STR(LINK_FAILURE), DP_STR(NO_RESOURCES), DP_STR(DPCD_FAIL), DP_STR(I2C_NAK), DP_STR(ALLOCATE_FAIL), }; if (nak_reason >= ARRAY_SIZE(nak_reason_str) || !nak_reason_str[nak_reason]) return "unknown"; return nak_reason_str[nak_reason]; } #undef DP_STR #define DP_STR(x) [DRM_DP_SIDEBAND_TX_ ## x] = #x static const char *drm_dp_mst_sideband_tx_state_str(int state) { static const char * const sideband_reason_str[] = { DP_STR(QUEUED), DP_STR(START_SEND), DP_STR(SENT), DP_STR(RX), DP_STR(TIMEOUT), }; if (state >= ARRAY_SIZE(sideband_reason_str) || !sideband_reason_str[state]) return "unknown"; return sideband_reason_str[state]; } static int drm_dp_mst_rad_to_str(const u8 rad[8], u8 lct, char *out, size_t len) { int i; u8 unpacked_rad[16]; for (i = 0; i < lct; i++) { if (i % 2) unpacked_rad[i] = rad[i / 2] >> 4; else unpacked_rad[i] = rad[i / 2] & BIT_MASK(4); } /* TODO: Eventually add something to printk so we can format the rad * like this: 1.2.3 */ return snprintf(out, len, "%*phC", lct, unpacked_rad); } /* sideband msg handling */ static u8 drm_dp_msg_header_crc4(const uint8_t *data, size_t num_nibbles) { u8 bitmask = 0x80; u8 bitshift = 7; u8 array_index = 0; int number_of_bits = num_nibbles * 4; u8 remainder = 0; while (number_of_bits != 0) { number_of_bits--; remainder <<= 1; remainder |= (data[array_index] & bitmask) >> bitshift; bitmask >>= 1; bitshift--; if (bitmask == 0) { bitmask = 0x80; bitshift = 7; array_index++; } if ((remainder & 0x10) == 0x10) remainder ^= 0x13; } number_of_bits = 4; while (number_of_bits != 0) { number_of_bits--; remainder <<= 1; if ((remainder & 0x10) != 0) remainder ^= 0x13; } return remainder; } static u8 drm_dp_msg_data_crc4(const uint8_t *data, u8 number_of_bytes) { u8 bitmask = 0x80; u8 bitshift = 7; u8 array_index = 0; int number_of_bits = number_of_bytes * 8; u16 remainder = 0; while (number_of_bits != 0) { number_of_bits--; remainder <<= 1; remainder |= (data[array_index] & bitmask) >> bitshift; bitmask >>= 1; bitshift--; if (bitmask == 0) { bitmask = 0x80; bitshift = 7; array_index++; } if ((remainder & 0x100) == 0x100) remainder ^= 0xd5; } number_of_bits = 8; while (number_of_bits != 0) { number_of_bits--; remainder <<= 1; if ((remainder & 0x100) != 0) remainder ^= 0xd5; } return remainder & 0xff; } static inline u8 drm_dp_calc_sb_hdr_size(struct drm_dp_sideband_msg_hdr *hdr) { u8 size = 3; size += (hdr->lct / 2); return size; } static void drm_dp_encode_sideband_msg_hdr(struct drm_dp_sideband_msg_hdr *hdr, u8 *buf, int *len) { int idx = 0; int i; u8 crc4; buf[idx++] = ((hdr->lct & 0xf) << 4) | (hdr->lcr & 0xf); for (i = 0; i < (hdr->lct / 2); i++) buf[idx++] = hdr->rad[i]; buf[idx++] = (hdr->broadcast << 7) | (hdr->path_msg << 6) | (hdr->msg_len & 0x3f); buf[idx++] = (hdr->somt << 7) | (hdr->eomt << 6) | (hdr->seqno << 4); crc4 = drm_dp_msg_header_crc4(buf, (idx * 2) - 1); buf[idx - 1] |= (crc4 & 0xf); *len = idx; } static bool drm_dp_decode_sideband_msg_hdr(struct drm_dp_sideband_msg_hdr *hdr, u8 *buf, int buflen, u8 *hdrlen) { u8 crc4; u8 len; int i; u8 idx; if (buf[0] == 0) return false; len = 3; len += ((buf[0] & 0xf0) >> 4) / 2; if (len > buflen) return false; crc4 = drm_dp_msg_header_crc4(buf, (len * 2) - 1); if ((crc4 & 0xf) != (buf[len - 1] & 0xf)) { DRM_DEBUG_KMS("crc4 mismatch 0x%x 0x%x\n", crc4, buf[len - 1]); return false; } hdr->lct = (buf[0] & 0xf0) >> 4; hdr->lcr = (buf[0] & 0xf); idx = 1; for (i = 0; i < (hdr->lct / 2); i++) hdr->rad[i] = buf[idx++]; hdr->broadcast = (buf[idx] >> 7) & 0x1; hdr->path_msg = (buf[idx] >> 6) & 0x1; hdr->msg_len = buf[idx] & 0x3f; idx++; hdr->somt = (buf[idx] >> 7) & 0x1; hdr->eomt = (buf[idx] >> 6) & 0x1; hdr->seqno = (buf[idx] >> 4) & 0x1; idx++; *hdrlen = idx; return true; } void drm_dp_encode_sideband_req(const struct drm_dp_sideband_msg_req_body *req, struct drm_dp_sideband_msg_tx *raw) { int idx = 0; int i; u8 *buf = raw->msg; buf[idx++] = req->req_type & 0x7f; switch (req->req_type) { case DP_ENUM_PATH_RESOURCES: case DP_POWER_DOWN_PHY: case DP_POWER_UP_PHY: buf[idx] = (req->u.port_num.port_number & 0xf) << 4; idx++; break; case DP_ALLOCATE_PAYLOAD: buf[idx] = (req->u.allocate_payload.port_number & 0xf) << 4 | (req->u.allocate_payload.number_sdp_streams & 0xf); idx++; buf[idx] = (req->u.allocate_payload.vcpi & 0x7f); idx++; buf[idx] = (req->u.allocate_payload.pbn >> 8); idx++; buf[idx] = (req->u.allocate_payload.pbn & 0xff); idx++; for (i = 0; i < req->u.allocate_payload.number_sdp_streams / 2; i++) { buf[idx] = ((req->u.allocate_payload.sdp_stream_sink[i * 2] & 0xf) << 4) | (req->u.allocate_payload.sdp_stream_sink[i * 2 + 1] & 0xf); idx++; } if (req->u.allocate_payload.number_sdp_streams & 1) { i = req->u.allocate_payload.number_sdp_streams - 1; buf[idx] = (req->u.allocate_payload.sdp_stream_sink[i] & 0xf) << 4; idx++; } break; case DP_QUERY_PAYLOAD: buf[idx] = (req->u.query_payload.port_number & 0xf) << 4; idx++; buf[idx] = (req->u.query_payload.vcpi & 0x7f); idx++; break; case DP_REMOTE_DPCD_READ: buf[idx] = (req->u.dpcd_read.port_number & 0xf) << 4; buf[idx] |= ((req->u.dpcd_read.dpcd_address & 0xf0000) >> 16) & 0xf; idx++; buf[idx] = (req->u.dpcd_read.dpcd_address & 0xff00) >> 8; idx++; buf[idx] = (req->u.dpcd_read.dpcd_address & 0xff); idx++; buf[idx] = (req->u.dpcd_read.num_bytes); idx++; break; case DP_REMOTE_DPCD_WRITE: buf[idx] = (req->u.dpcd_write.port_number & 0xf) << 4; buf[idx] |= ((req->u.dpcd_write.dpcd_address & 0xf0000) >> 16) & 0xf; idx++; buf[idx] = (req->u.dpcd_write.dpcd_address & 0xff00) >> 8; idx++; buf[idx] = (req->u.dpcd_write.dpcd_address & 0xff); idx++; buf[idx] = (req->u.dpcd_write.num_bytes); idx++; memcpy(&buf[idx], req->u.dpcd_write.bytes, req->u.dpcd_write.num_bytes); idx += req->u.dpcd_write.num_bytes; break; case DP_REMOTE_I2C_READ: buf[idx] = (req->u.i2c_read.port_number & 0xf) << 4; buf[idx] |= (req->u.i2c_read.num_transactions & 0x3); idx++; for (i = 0; i < (req->u.i2c_read.num_transactions & 0x3); i++) { buf[idx] = req->u.i2c_read.transactions[i].i2c_dev_id & 0x7f; idx++; buf[idx] = req->u.i2c_read.transactions[i].num_bytes; idx++; memcpy(&buf[idx], req->u.i2c_read.transactions[i].bytes, req->u.i2c_read.transactions[i].num_bytes); idx += req->u.i2c_read.transactions[i].num_bytes; buf[idx] = (req->u.i2c_read.transactions[i].no_stop_bit & 0x1) << 4; buf[idx] |= (req->u.i2c_read.transactions[i].i2c_transaction_delay & 0xf); idx++; } buf[idx] = (req->u.i2c_read.read_i2c_device_id) & 0x7f; idx++; buf[idx] = (req->u.i2c_read.num_bytes_read); idx++; break; case DP_REMOTE_I2C_WRITE: buf[idx] = (req->u.i2c_write.port_number & 0xf) << 4; idx++; buf[idx] = (req->u.i2c_write.write_i2c_device_id) & 0x7f; idx++; buf[idx] = (req->u.i2c_write.num_bytes); idx++; memcpy(&buf[idx], req->u.i2c_write.bytes, req->u.i2c_write.num_bytes); idx += req->u.i2c_write.num_bytes; break; } raw->cur_len = idx; } EXPORT_SYMBOL_FOR_TESTS_ONLY(drm_dp_encode_sideband_req); /* Decode a sideband request we've encoded, mainly used for debugging */ int drm_dp_decode_sideband_req(const struct drm_dp_sideband_msg_tx *raw, struct drm_dp_sideband_msg_req_body *req) { const u8 *buf = raw->msg; int i, idx = 0; req->req_type = buf[idx++] & 0x7f; switch (req->req_type) { case DP_ENUM_PATH_RESOURCES: case DP_POWER_DOWN_PHY: case DP_POWER_UP_PHY: req->u.port_num.port_number = (buf[idx] >> 4) & 0xf; break; case DP_ALLOCATE_PAYLOAD: { struct drm_dp_allocate_payload *a = &req->u.allocate_payload; a->number_sdp_streams = buf[idx] & 0xf; a->port_number = (buf[idx] >> 4) & 0xf; WARN_ON(buf[++idx] & 0x80); a->vcpi = buf[idx] & 0x7f; a->pbn = buf[++idx] << 8; a->pbn |= buf[++idx]; idx++; for (i = 0; i < a->number_sdp_streams; i++) { a->sdp_stream_sink[i] = (buf[idx + (i / 2)] >> ((i % 2) ? 0 : 4)) & 0xf; } } break; case DP_QUERY_PAYLOAD: req->u.query_payload.port_number = (buf[idx] >> 4) & 0xf; WARN_ON(buf[++idx] & 0x80); req->u.query_payload.vcpi = buf[idx] & 0x7f; break; case DP_REMOTE_DPCD_READ: { struct drm_dp_remote_dpcd_read *r = &req->u.dpcd_read; r->port_number = (buf[idx] >> 4) & 0xf; r->dpcd_address = (buf[idx] << 16) & 0xf0000; r->dpcd_address |= (buf[++idx] << 8) & 0xff00; r->dpcd_address |= buf[++idx] & 0xff; r->num_bytes = buf[++idx]; } break; case DP_REMOTE_DPCD_WRITE: { struct drm_dp_remote_dpcd_write *w = &req->u.dpcd_write; w->port_number = (buf[idx] >> 4) & 0xf; w->dpcd_address = (buf[idx] << 16) & 0xf0000; w->dpcd_address |= (buf[++idx] << 8) & 0xff00; w->dpcd_address |= buf[++idx] & 0xff; w->num_bytes = buf[++idx]; w->bytes = kmemdup(&buf[++idx], w->num_bytes, GFP_KERNEL); if (!w->bytes) return -ENOMEM; } break; case DP_REMOTE_I2C_READ: { struct drm_dp_remote_i2c_read *r = &req->u.i2c_read; struct drm_dp_remote_i2c_read_tx *tx; bool failed = false; r->num_transactions = buf[idx] & 0x3; r->port_number = (buf[idx] >> 4) & 0xf; for (i = 0; i < r->num_transactions; i++) { tx = &r->transactions[i]; tx->i2c_dev_id = buf[++idx] & 0x7f; tx->num_bytes = buf[++idx]; tx->bytes = kmemdup(&buf[++idx], tx->num_bytes, GFP_KERNEL); if (!tx->bytes) { failed = true; break; } idx += tx->num_bytes; tx->no_stop_bit = (buf[idx] >> 5) & 0x1; tx->i2c_transaction_delay = buf[idx] & 0xf; } if (failed) { for (i = 0; i < r->num_transactions; i++) { tx = &r->transactions[i]; kfree(tx->bytes); } return -ENOMEM; } r->read_i2c_device_id = buf[++idx] & 0x7f; r->num_bytes_read = buf[++idx]; } break; case DP_REMOTE_I2C_WRITE: { struct drm_dp_remote_i2c_write *w = &req->u.i2c_write; w->port_number = (buf[idx] >> 4) & 0xf; w->write_i2c_device_id = buf[++idx] & 0x7f; w->num_bytes = buf[++idx]; w->bytes = kmemdup(&buf[++idx], w->num_bytes, GFP_KERNEL); if (!w->bytes) return -ENOMEM; } break; } return 0; } EXPORT_SYMBOL_FOR_TESTS_ONLY(drm_dp_decode_sideband_req); void drm_dp_dump_sideband_msg_req_body(const struct drm_dp_sideband_msg_req_body *req, int indent, struct drm_printer *printer) { int i; #define P(f, ...) drm_printf_indent(printer, indent, f, ##__VA_ARGS__) if (req->req_type == DP_LINK_ADDRESS) { /* No contents to print */ P("type=%s\n", drm_dp_mst_req_type_str(req->req_type)); return; } P("type=%s contents:\n", drm_dp_mst_req_type_str(req->req_type)); indent++; switch (req->req_type) { case DP_ENUM_PATH_RESOURCES: case DP_POWER_DOWN_PHY: case DP_POWER_UP_PHY: P("port=%d\n", req->u.port_num.port_number); break; case DP_ALLOCATE_PAYLOAD: P("port=%d vcpi=%d pbn=%d sdp_streams=%d %*ph\n", req->u.allocate_payload.port_number, req->u.allocate_payload.vcpi, req->u.allocate_payload.pbn, req->u.allocate_payload.number_sdp_streams, req->u.allocate_payload.number_sdp_streams, req->u.allocate_payload.sdp_stream_sink); break; case DP_QUERY_PAYLOAD: P("port=%d vcpi=%d\n", req->u.query_payload.port_number, req->u.query_payload.vcpi); break; case DP_REMOTE_DPCD_READ: P("port=%d dpcd_addr=%05x len=%d\n", req->u.dpcd_read.port_number, req->u.dpcd_read.dpcd_address, req->u.dpcd_read.num_bytes); break; case DP_REMOTE_DPCD_WRITE: P("port=%d addr=%05x len=%d: %*ph\n", req->u.dpcd_write.port_number, req->u.dpcd_write.dpcd_address, req->u.dpcd_write.num_bytes, req->u.dpcd_write.num_bytes, req->u.dpcd_write.bytes); break; case DP_REMOTE_I2C_READ: P("port=%d num_tx=%d id=%d size=%d:\n", req->u.i2c_read.port_number, req->u.i2c_read.num_transactions, req->u.i2c_read.read_i2c_device_id, req->u.i2c_read.num_bytes_read); indent++; for (i = 0; i < req->u.i2c_read.num_transactions; i++) { const struct drm_dp_remote_i2c_read_tx *rtx = &req->u.i2c_read.transactions[i]; P("%d: id=%03d size=%03d no_stop_bit=%d tx_delay=%03d: %*ph\n", i, rtx->i2c_dev_id, rtx->num_bytes, rtx->no_stop_bit, rtx->i2c_transaction_delay, rtx->num_bytes, rtx->bytes); } break; case DP_REMOTE_I2C_WRITE: P("port=%d id=%d size=%d: %*ph\n", req->u.i2c_write.port_number, req->u.i2c_write.write_i2c_device_id, req->u.i2c_write.num_bytes, req->u.i2c_write.num_bytes, req->u.i2c_write.bytes); break; default: P("???\n"); break; } #undef P } EXPORT_SYMBOL_FOR_TESTS_ONLY(drm_dp_dump_sideband_msg_req_body); static inline void drm_dp_mst_dump_sideband_msg_tx(struct drm_printer *p, const struct drm_dp_sideband_msg_tx *txmsg) { struct drm_dp_sideband_msg_req_body req; char buf[64]; int ret; int i; drm_dp_mst_rad_to_str(txmsg->dst->rad, txmsg->dst->lct, buf, sizeof(buf)); drm_printf(p, "txmsg cur_offset=%x cur_len=%x seqno=%x state=%s path_msg=%d dst=%s\n", txmsg->cur_offset, txmsg->cur_len, txmsg->seqno, drm_dp_mst_sideband_tx_state_str(txmsg->state), txmsg->path_msg, buf); ret = drm_dp_decode_sideband_req(txmsg, &req); if (ret) { drm_printf(p, "<failed to decode sideband req: %d>\n", ret); return; } drm_dp_dump_sideband_msg_req_body(&req, 1, p); switch (req.req_type) { case DP_REMOTE_DPCD_WRITE: kfree(req.u.dpcd_write.bytes); break; case DP_REMOTE_I2C_READ: for (i = 0; i < req.u.i2c_read.num_transactions; i++) kfree(req.u.i2c_read.transactions[i].bytes); break; case DP_REMOTE_I2C_WRITE: kfree(req.u.i2c_write.bytes); break; } } static void drm_dp_crc_sideband_chunk_req(u8 *msg, u8 len) { u8 crc4; crc4 = drm_dp_msg_data_crc4(msg, len); msg[len] = crc4; } static void drm_dp_encode_sideband_reply(struct drm_dp_sideband_msg_reply_body *rep, struct drm_dp_sideband_msg_tx *raw) { int idx = 0; u8 *buf = raw->msg; buf[idx++] = (rep->reply_type & 0x1) << 7 | (rep->req_type & 0x7f); raw->cur_len = idx; } /* this adds a chunk of msg to the builder to get the final msg */ static bool drm_dp_sideband_msg_build(struct drm_dp_sideband_msg_rx *msg, u8 *replybuf, u8 replybuflen, bool hdr) { int ret; u8 crc4; if (hdr) { u8 hdrlen; struct drm_dp_sideband_msg_hdr recv_hdr; ret = drm_dp_decode_sideband_msg_hdr(&recv_hdr, replybuf, replybuflen, &hdrlen); if (ret == false) { print_hex_dump(KERN_DEBUG, "failed hdr", DUMP_PREFIX_NONE, 16, 1, replybuf, replybuflen, false); return false; } /* * ignore out-of-order messages or messages that are part of a * failed transaction */ if (!recv_hdr.somt && !msg->have_somt) return false; /* get length contained in this portion */ msg->curchunk_len = recv_hdr.msg_len; msg->curchunk_hdrlen = hdrlen; /* we have already gotten an somt - don't bother parsing */ if (recv_hdr.somt && msg->have_somt) return false; if (recv_hdr.somt) { memcpy(&msg->initial_hdr, &recv_hdr, sizeof(struct drm_dp_sideband_msg_hdr)); msg->have_somt = true; } if (recv_hdr.eomt) msg->have_eomt = true; /* copy the bytes for the remainder of this header chunk */ msg->curchunk_idx = min(msg->curchunk_len, (u8)(replybuflen - hdrlen)); memcpy(&msg->chunk[0], replybuf + hdrlen, msg->curchunk_idx); } else { memcpy(&msg->chunk[msg->curchunk_idx], replybuf, replybuflen); msg->curchunk_idx += replybuflen; } if (msg->curchunk_idx >= msg->curchunk_len) { /* do CRC */ crc4 = drm_dp_msg_data_crc4(msg->chunk, msg->curchunk_len - 1); if (crc4 != msg->chunk[msg->curchunk_len - 1]) print_hex_dump(KERN_DEBUG, "wrong crc", DUMP_PREFIX_NONE, 16, 1, msg->chunk, msg->curchunk_len, false); /* copy chunk into bigger msg */ memcpy(&msg->msg[msg->curlen], msg->chunk, msg->curchunk_len - 1); msg->curlen += msg->curchunk_len - 1; } return true; } static bool drm_dp_sideband_parse_link_address(struct drm_dp_sideband_msg_rx *raw, struct drm_dp_sideband_msg_reply_body *repmsg) { int idx = 1; int i; memcpy(repmsg->u.link_addr.guid, &raw->msg[idx], 16); idx += 16; repmsg->u.link_addr.nports = raw->msg[idx] & 0xf; idx++; if (idx > raw->curlen) goto fail_len; for (i = 0; i < repmsg->u.link_addr.nports; i++) { if (raw->msg[idx] & 0x80) repmsg->u.link_addr.ports[i].input_port = 1; repmsg->u.link_addr.ports[i].peer_device_type = (raw->msg[idx] >> 4) & 0x7; repmsg->u.link_addr.ports[i].port_number = (raw->msg[idx] & 0xf); idx++; if (idx > raw->curlen) goto fail_len; repmsg->u.link_addr.ports[i].mcs = (raw->msg[idx] >> 7) & 0x1; repmsg->u.link_addr.ports[i].ddps = (raw->msg[idx] >> 6) & 0x1; if (repmsg->u.link_addr.ports[i].input_port == 0) repmsg->u.link_addr.ports[i].legacy_device_plug_status = (raw->msg[idx] >> 5) & 0x1; idx++; if (idx > raw->curlen) goto fail_len; if (repmsg->u.link_addr.ports[i].input_port == 0) { repmsg->u.link_addr.ports[i].dpcd_revision = (raw->msg[idx]); idx++; if (idx > raw->curlen) goto fail_len; memcpy(repmsg->u.link_addr.ports[i].peer_guid, &raw->msg[idx], 16); idx += 16; if (idx > raw->curlen) goto fail_len; repmsg->u.link_addr.ports[i].num_sdp_streams = (raw->msg[idx] >> 4) & 0xf; repmsg->u.link_addr.ports[i].num_sdp_stream_sinks = (raw->msg[idx] & 0xf); idx++; } if (idx > raw->curlen) goto fail_len; } return true; fail_len: DRM_DEBUG_KMS("link address reply parse length fail %d %d\n", idx, raw->curlen); return false; } static bool drm_dp_sideband_parse_remote_dpcd_read(struct drm_dp_sideband_msg_rx *raw, struct drm_dp_sideband_msg_reply_body *repmsg) { int idx = 1; repmsg->u.remote_dpcd_read_ack.port_number = raw->msg[idx] & 0xf; idx++; if (idx > raw->curlen) goto fail_len; repmsg->u.remote_dpcd_read_ack.num_bytes = raw->msg[idx]; idx++; if (idx > raw->curlen) goto fail_len; memcpy(repmsg->u.remote_dpcd_read_ack.bytes, &raw->msg[idx], repmsg->u.remote_dpcd_read_ack.num_bytes); return true; fail_len: DRM_DEBUG_KMS("link address reply parse length fail %d %d\n", idx, raw->curlen); return false; } static bool drm_dp_sideband_parse_remote_dpcd_write(struct drm_dp_sideband_msg_rx *raw, struct drm_dp_sideband_msg_reply_body *repmsg) { int idx = 1; repmsg->u.remote_dpcd_write_ack.port_number = raw->msg[idx] & 0xf; idx++; if (idx > raw->curlen) goto fail_len; return true; fail_len: DRM_DEBUG_KMS("parse length fail %d %d\n", idx, raw->curlen); return false; } static bool drm_dp_sideband_parse_remote_i2c_read_ack(struct drm_dp_sideband_msg_rx *raw, struct drm_dp_sideband_msg_reply_body *repmsg) { int idx = 1; repmsg->u.remote_i2c_read_ack.port_number = (raw->msg[idx] & 0xf); idx++; if (idx > raw->curlen) goto fail_len; repmsg->u.remote_i2c_read_ack.num_bytes = raw->msg[idx]; idx++; /* TODO check */ memcpy(repmsg->u.remote_i2c_read_ack.bytes, &raw->msg[idx], repmsg->u.remote_i2c_read_ack.num_bytes); return true; fail_len: DRM_DEBUG_KMS("remote i2c reply parse length fail %d %d\n", idx, raw->curlen); return false; } static bool drm_dp_sideband_parse_enum_path_resources_ack(struct drm_dp_sideband_msg_rx *raw, struct drm_dp_sideband_msg_reply_body *repmsg) { int idx = 1; repmsg->u.path_resources.port_number = (raw->msg[idx] >> 4) & 0xf; repmsg->u.path_resources.fec_capable = raw->msg[idx] & 0x1; idx++; if (idx > raw->curlen) goto fail_len; repmsg->u.path_resources.full_payload_bw_number = (raw->msg[idx] << 8) | (raw->msg[idx+1]); idx += 2; if (idx > raw->curlen) goto fail_len; repmsg->u.path_resources.avail_payload_bw_number = (raw->msg[idx] << 8) | (raw->msg[idx+1]); idx += 2; if (idx > raw->curlen) goto fail_len; return true; fail_len: DRM_DEBUG_KMS("enum resource parse length fail %d %d\n", idx, raw->curlen); return false; } static bool drm_dp_sideband_parse_allocate_payload_ack(struct drm_dp_sideband_msg_rx *raw, struct drm_dp_sideband_msg_reply_body *repmsg) { int idx = 1; repmsg->u.allocate_payload.port_number = (raw->msg[idx] >> 4) & 0xf; idx++; if (idx > raw->curlen) goto fail_len; repmsg->u.allocate_payload.vcpi = raw->msg[idx]; idx++; if (idx > raw->curlen) goto fail_len; repmsg->u.allocate_payload.allocated_pbn = (raw->msg[idx] << 8) | (raw->msg[idx+1]); idx += 2; if (idx > raw->curlen) goto fail_len; return true; fail_len: DRM_DEBUG_KMS("allocate payload parse length fail %d %d\n", idx, raw->curlen); return false; } static bool drm_dp_sideband_parse_query_payload_ack(struct drm_dp_sideband_msg_rx *raw, struct drm_dp_sideband_msg_reply_body *repmsg) { int idx = 1; repmsg->u.query_payload.port_number = (raw->msg[idx] >> 4) & 0xf; idx++; if (idx > raw->curlen) goto fail_len; repmsg->u.query_payload.allocated_pbn = (raw->msg[idx] << 8) | (raw->msg[idx + 1]); idx += 2; if (idx > raw->curlen) goto fail_len; return true; fail_len: DRM_DEBUG_KMS("query payload parse length fail %d %d\n", idx, raw->curlen); return false; } static bool drm_dp_sideband_parse_power_updown_phy_ack(struct drm_dp_sideband_msg_rx *raw, struct drm_dp_sideband_msg_reply_body *repmsg) { int idx = 1; repmsg->u.port_number.port_number = (raw->msg[idx] >> 4) & 0xf; idx++; if (idx > raw->curlen) { DRM_DEBUG_KMS("power up/down phy parse length fail %d %d\n", idx, raw->curlen); return false; } return true; } static bool drm_dp_sideband_parse_reply(struct drm_dp_sideband_msg_rx *raw, struct drm_dp_sideband_msg_reply_body *msg) { memset(msg, 0, sizeof(*msg)); msg->reply_type = (raw->msg[0] & 0x80) >> 7; msg->req_type = (raw->msg[0] & 0x7f); if (msg->reply_type == DP_SIDEBAND_REPLY_NAK) { memcpy(msg->u.nak.guid, &raw->msg[1], 16); msg->u.nak.reason = raw->msg[17]; msg->u.nak.nak_data = raw->msg[18]; return false; } switch (msg->req_type) { case DP_LINK_ADDRESS: return drm_dp_sideband_parse_link_address(raw, msg); case DP_QUERY_PAYLOAD: return drm_dp_sideband_parse_query_payload_ack(raw, msg); case DP_REMOTE_DPCD_READ: return drm_dp_sideband_parse_remote_dpcd_read(raw, msg); case DP_REMOTE_DPCD_WRITE: return drm_dp_sideband_parse_remote_dpcd_write(raw, msg); case DP_REMOTE_I2C_READ: return drm_dp_sideband_parse_remote_i2c_read_ack(raw, msg); case DP_ENUM_PATH_RESOURCES: return drm_dp_sideband_parse_enum_path_resources_ack(raw, msg); case DP_ALLOCATE_PAYLOAD: return drm_dp_sideband_parse_allocate_payload_ack(raw, msg); case DP_POWER_DOWN_PHY: case DP_POWER_UP_PHY: return drm_dp_sideband_parse_power_updown_phy_ack(raw, msg); case DP_CLEAR_PAYLOAD_ID_TABLE: return true; /* since there's nothing to parse */ default: DRM_ERROR("Got unknown reply 0x%02x (%s)\n", msg->req_type, drm_dp_mst_req_type_str(msg->req_type)); return false; } } static bool drm_dp_sideband_parse_connection_status_notify(struct drm_dp_sideband_msg_rx *raw, struct drm_dp_sideband_msg_req_body *msg) { int idx = 1; msg->u.conn_stat.port_number = (raw->msg[idx] & 0xf0) >> 4; idx++; if (idx > raw->curlen) goto fail_len; memcpy(msg->u.conn_stat.guid, &raw->msg[idx], 16); idx += 16; if (idx > raw->curlen) goto fail_len; msg->u.conn_stat.legacy_device_plug_status = (raw->msg[idx] >> 6) & 0x1; msg->u.conn_stat.displayport_device_plug_status = (raw->msg[idx] >> 5) & 0x1; msg->u.conn_stat.message_capability_status = (raw->msg[idx] >> 4) & 0x1; msg->u.conn_stat.input_port = (raw->msg[idx] >> 3) & 0x1; msg->u.conn_stat.peer_device_type = (raw->msg[idx] & 0x7); idx++; return true; fail_len: DRM_DEBUG_KMS("connection status reply parse length fail %d %d\n", idx, raw->curlen); return false; } static bool drm_dp_sideband_parse_resource_status_notify(struct drm_dp_sideband_msg_rx *raw, struct drm_dp_sideband_msg_req_body *msg) { int idx = 1; msg->u.resource_stat.port_number = (raw->msg[idx] & 0xf0) >> 4; idx++; if (idx > raw->curlen) goto fail_len; memcpy(msg->u.resource_stat.guid, &raw->msg[idx], 16); idx += 16; if (idx > raw->curlen) goto fail_len; msg->u.resource_stat.available_pbn = (raw->msg[idx] << 8) | (raw->msg[idx + 1]); idx++; return true; fail_len: DRM_DEBUG_KMS("resource status reply parse length fail %d %d\n", idx, raw->curlen); return false; } static bool drm_dp_sideband_parse_req(struct drm_dp_sideband_msg_rx *raw, struct drm_dp_sideband_msg_req_body *msg) { memset(msg, 0, sizeof(*msg)); msg->req_type = (raw->msg[0] & 0x7f); switch (msg->req_type) { case DP_CONNECTION_STATUS_NOTIFY: return drm_dp_sideband_parse_connection_status_notify(raw, msg); case DP_RESOURCE_STATUS_NOTIFY: return drm_dp_sideband_parse_resource_status_notify(raw, msg); default: DRM_ERROR("Got unknown request 0x%02x (%s)\n", msg->req_type, drm_dp_mst_req_type_str(msg->req_type)); return false; } } static void build_dpcd_write(struct drm_dp_sideband_msg_tx *msg, u8 port_num, u32 offset, u8 num_bytes, u8 *bytes) { struct drm_dp_sideband_msg_req_body req; req.req_type = DP_REMOTE_DPCD_WRITE; req.u.dpcd_write.port_number = port_num; req.u.dpcd_write.dpcd_address = offset; req.u.dpcd_write.num_bytes = num_bytes; req.u.dpcd_write.bytes = bytes; drm_dp_encode_sideband_req(&req, msg); } static void build_link_address(struct drm_dp_sideband_msg_tx *msg) { struct drm_dp_sideband_msg_req_body req; req.req_type = DP_LINK_ADDRESS; drm_dp_encode_sideband_req(&req, msg); } static int build_clear_payload_id_table(struct drm_dp_sideband_msg_tx *msg) { struct drm_dp_sideband_msg_req_body req; req.req_type = DP_CLEAR_PAYLOAD_ID_TABLE; drm_dp_encode_sideband_req(&req, msg); return 0; } static int build_enum_path_resources(struct drm_dp_sideband_msg_tx *msg, int port_num) { struct drm_dp_sideband_msg_req_body req; req.req_type = DP_ENUM_PATH_RESOURCES; req.u.port_num.port_number = port_num; drm_dp_encode_sideband_req(&req, msg); msg->path_msg = true; return 0; } static void build_allocate_payload(struct drm_dp_sideband_msg_tx *msg, int port_num, u8 vcpi, uint16_t pbn, u8 number_sdp_streams, u8 *sdp_stream_sink) { struct drm_dp_sideband_msg_req_body req; memset(&req, 0, sizeof(req)); req.req_type = DP_ALLOCATE_PAYLOAD; req.u.allocate_payload.port_number = port_num; req.u.allocate_payload.vcpi = vcpi; req.u.allocate_payload.pbn = pbn; req.u.allocate_payload.number_sdp_streams = number_sdp_streams; memcpy(req.u.allocate_payload.sdp_stream_sink, sdp_stream_sink, number_sdp_streams); drm_dp_encode_sideband_req(&req, msg); msg->path_msg = true; } static void build_power_updown_phy(struct drm_dp_sideband_msg_tx *msg, int port_num, bool power_up) { struct drm_dp_sideband_msg_req_body req; if (power_up) req.req_type = DP_POWER_UP_PHY; else req.req_type = DP_POWER_DOWN_PHY; req.u.port_num.port_number = port_num; drm_dp_encode_sideband_req(&req, msg); msg->path_msg = true; } static int drm_dp_mst_assign_payload_id(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_vcpi *vcpi) { int ret, vcpi_ret; mutex_lock(&mgr->payload_lock); ret = find_first_zero_bit(&mgr->payload_mask, mgr->max_payloads + 1); if (ret > mgr->max_payloads) { ret = -EINVAL; DRM_DEBUG_KMS("out of payload ids %d\n", ret); goto out_unlock; } vcpi_ret = find_first_zero_bit(&mgr->vcpi_mask, mgr->max_payloads + 1); if (vcpi_ret > mgr->max_payloads) { ret = -EINVAL; DRM_DEBUG_KMS("out of vcpi ids %d\n", ret); goto out_unlock; } set_bit(ret, &mgr->payload_mask); set_bit(vcpi_ret, &mgr->vcpi_mask); vcpi->vcpi = vcpi_ret + 1; mgr->proposed_vcpis[ret - 1] = vcpi; out_unlock: mutex_unlock(&mgr->payload_lock); return ret; } static void drm_dp_mst_put_payload_id(struct drm_dp_mst_topology_mgr *mgr, int vcpi) { int i; if (vcpi == 0) return; mutex_lock(&mgr->payload_lock); DRM_DEBUG_KMS("putting payload %d\n", vcpi); clear_bit(vcpi - 1, &mgr->vcpi_mask); for (i = 0; i < mgr->max_payloads; i++) { if (mgr->proposed_vcpis[i] && mgr->proposed_vcpis[i]->vcpi == vcpi) { mgr->proposed_vcpis[i] = NULL; clear_bit(i + 1, &mgr->payload_mask); } } mutex_unlock(&mgr->payload_lock); } static bool check_txmsg_state(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_sideband_msg_tx *txmsg) { unsigned int state; /* * All updates to txmsg->state are protected by mgr->qlock, and the two * cases we check here are terminal states. For those the barriers * provided by the wake_up/wait_event pair are enough. */ state = READ_ONCE(txmsg->state); return (state == DRM_DP_SIDEBAND_TX_RX || state == DRM_DP_SIDEBAND_TX_TIMEOUT); } static int drm_dp_mst_wait_tx_reply(struct drm_dp_mst_branch *mstb, struct drm_dp_sideband_msg_tx *txmsg) { struct drm_dp_mst_topology_mgr *mgr = mstb->mgr; int ret; ret = wait_event_timeout(mgr->tx_waitq, check_txmsg_state(mgr, txmsg), (4 * HZ)); mutex_lock(&mstb->mgr->qlock); if (ret > 0) { if (txmsg->state == DRM_DP_SIDEBAND_TX_TIMEOUT) { ret = -EIO; goto out; } } else { DRM_DEBUG_KMS("timedout msg send %p %d %d\n", txmsg, txmsg->state, txmsg->seqno); /* dump some state */ ret = -EIO; /* remove from q */ if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED || txmsg->state == DRM_DP_SIDEBAND_TX_START_SEND) { list_del(&txmsg->next); } if (txmsg->state == DRM_DP_SIDEBAND_TX_START_SEND || txmsg->state == DRM_DP_SIDEBAND_TX_SENT) { mstb->tx_slots[txmsg->seqno] = NULL; } mgr->is_waiting_for_dwn_reply = false; } out: if (unlikely(ret == -EIO) && drm_debug_enabled(DRM_UT_DP)) { struct drm_printer p = drm_debug_printer(DBG_PREFIX); drm_dp_mst_dump_sideband_msg_tx(&p, txmsg); } mutex_unlock(&mgr->qlock); drm_dp_mst_kick_tx(mgr); return ret; } static struct drm_dp_mst_branch *drm_dp_add_mst_branch_device(u8 lct, u8 *rad) { struct drm_dp_mst_branch *mstb; mstb = kzalloc(sizeof(*mstb), GFP_KERNEL); if (!mstb) return NULL; mstb->lct = lct; if (lct > 1) memcpy(mstb->rad, rad, lct / 2); INIT_LIST_HEAD(&mstb->ports); kref_init(&mstb->topology_kref); kref_init(&mstb->malloc_kref); return mstb; } static void drm_dp_free_mst_branch_device(struct kref *kref) { struct drm_dp_mst_branch *mstb = container_of(kref, struct drm_dp_mst_branch, malloc_kref); if (mstb->port_parent) drm_dp_mst_put_port_malloc(mstb->port_parent); kfree(mstb); } /** * DOC: Branch device and port refcounting * * Topology refcount overview * ~~~~~~~~~~~~~~~~~~~~~~~~~~ * * The refcounting schemes for &struct drm_dp_mst_branch and &struct * drm_dp_mst_port are somewhat unusual. Both ports and branch devices have * two different kinds of refcounts: topology refcounts, and malloc refcounts. * * Topology refcounts are not exposed to drivers, and are handled internally * by the DP MST helpers. The helpers use them in order to prevent the * in-memory topology state from being changed in the middle of critical * operations like changing the internal state of payload allocations. This * means each branch and port will be considered to be connected to the rest * of the topology until its topology refcount reaches zero. Additionally, * for ports this means that their associated &struct drm_connector will stay * registered with userspace until the port's refcount reaches 0. * * Malloc refcount overview * ~~~~~~~~~~~~~~~~~~~~~~~~ * * Malloc references are used to keep a &struct drm_dp_mst_port or &struct * drm_dp_mst_branch allocated even after all of its topology references have * been dropped, so that the driver or MST helpers can safely access each * branch's last known state before it was disconnected from the topology. * When the malloc refcount of a port or branch reaches 0, the memory * allocation containing the &struct drm_dp_mst_branch or &struct * drm_dp_mst_port respectively will be freed. * * For &struct drm_dp_mst_branch, malloc refcounts are not currently exposed * to drivers. As of writing this documentation, there are no drivers that * have a usecase for accessing &struct drm_dp_mst_branch outside of the MST * helpers. Exposing this API to drivers in a race-free manner would take more * tweaking of the refcounting scheme, however patches are welcome provided * there is a legitimate driver usecase for this. * * Refcount relationships in a topology * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ * * Let's take a look at why the relationship between topology and malloc * refcounts is designed the way it is. * * .. kernel-figure:: dp-mst/topology-figure-1.dot * * An example of topology and malloc refs in a DP MST topology with two * active payloads. Topology refcount increments are indicated by solid * lines, and malloc refcount increments are indicated by dashed lines. * Each starts from the branch which incremented the refcount, and ends at * the branch to which the refcount belongs to, i.e. the arrow points the * same way as the C pointers used to reference a structure. * * As you can see in the above figure, every branch increments the topology * refcount of its children, and increments the malloc refcount of its * parent. Additionally, every payload increments the malloc refcount of its * assigned port by 1. * * So, what would happen if MSTB #3 from the above figure was unplugged from * the system, but the driver hadn't yet removed payload #2 from port #3? The * topology would start to look like the figure below. * * .. kernel-figure:: dp-mst/topology-figure-2.dot * * Ports and branch devices which have been released from memory are * colored grey, and references which have been removed are colored red. * * Whenever a port or branch device's topology refcount reaches zero, it will * decrement the topology refcounts of all its children, the malloc refcount * of its parent, and finally its own malloc refcount. For MSTB #4 and port * #4, this means they both have been disconnected from the topology and freed * from memory. But, because payload #2 is still holding a reference to port * #3, port #3 is removed from the topology but its &struct drm_dp_mst_port * is still accessible from memory. This also means port #3 has not yet * decremented the malloc refcount of MSTB #3, so its &struct * drm_dp_mst_branch will also stay allocated in memory until port #3's * malloc refcount reaches 0. * * This relationship is necessary because in order to release payload #2, we * need to be able to figure out the last relative of port #3 that's still * connected to the topology. In this case, we would travel up the topology as * shown below. * * .. kernel-figure:: dp-mst/topology-figure-3.dot * * And finally, remove payload #2 by communicating with port #2 through * sideband transactions. */ /** * drm_dp_mst_get_mstb_malloc() - Increment the malloc refcount of a branch * device * @mstb: The &struct drm_dp_mst_branch to increment the malloc refcount of * * Increments &drm_dp_mst_branch.malloc_kref. When * &drm_dp_mst_branch.malloc_kref reaches 0, the memory allocation for @mstb * will be released and @mstb may no longer be used. * * See also: drm_dp_mst_put_mstb_malloc() */ static void drm_dp_mst_get_mstb_malloc(struct drm_dp_mst_branch *mstb) { kref_get(&mstb->malloc_kref); DRM_DEBUG("mstb %p (%d)\n", mstb, kref_read(&mstb->malloc_kref)); } /** * drm_dp_mst_put_mstb_malloc() - Decrement the malloc refcount of a branch * device * @mstb: The &struct drm_dp_mst_branch to decrement the malloc refcount of * * Decrements &drm_dp_mst_branch.malloc_kref. When * &drm_dp_mst_branch.malloc_kref reaches 0, the memory allocation for @mstb * will be released and @mstb may no longer be used. * * See also: drm_dp_mst_get_mstb_malloc() */ static void drm_dp_mst_put_mstb_malloc(struct drm_dp_mst_branch *mstb) { DRM_DEBUG("mstb %p (%d)\n", mstb, kref_read(&mstb->malloc_kref) - 1); kref_put(&mstb->malloc_kref, drm_dp_free_mst_branch_device); } static void drm_dp_free_mst_port(struct kref *kref) { struct drm_dp_mst_port *port = container_of(kref, struct drm_dp_mst_port, malloc_kref); drm_dp_mst_put_mstb_malloc(port->parent); kfree(port); } /** * drm_dp_mst_get_port_malloc() - Increment the malloc refcount of an MST port * @port: The &struct drm_dp_mst_port to increment the malloc refcount of * * Increments &drm_dp_mst_port.malloc_kref. When &drm_dp_mst_port.malloc_kref * reaches 0, the memory allocation for @port will be released and @port may * no longer be used. * * Because @port could potentially be freed at any time by the DP MST helpers * if &drm_dp_mst_port.malloc_kref reaches 0, including during a call to this * function, drivers that which to make use of &struct drm_dp_mst_port should * ensure that they grab at least one main malloc reference to their MST ports * in &drm_dp_mst_topology_cbs.add_connector. This callback is called before * there is any chance for &drm_dp_mst_port.malloc_kref to reach 0. * * See also: drm_dp_mst_put_port_malloc() */ void drm_dp_mst_get_port_malloc(struct drm_dp_mst_port *port) { kref_get(&port->malloc_kref); DRM_DEBUG("port %p (%d)\n", port, kref_read(&port->malloc_kref)); } EXPORT_SYMBOL(drm_dp_mst_get_port_malloc); /** * drm_dp_mst_put_port_malloc() - Decrement the malloc refcount of an MST port * @port: The &struct drm_dp_mst_port to decrement the malloc refcount of * * Decrements &drm_dp_mst_port.malloc_kref. When &drm_dp_mst_port.malloc_kref * reaches 0, the memory allocation for @port will be released and @port may * no longer be used. * * See also: drm_dp_mst_get_port_malloc() */ void drm_dp_mst_put_port_malloc(struct drm_dp_mst_port *port) { DRM_DEBUG("port %p (%d)\n", port, kref_read(&port->malloc_kref) - 1); kref_put(&port->malloc_kref, drm_dp_free_mst_port); } EXPORT_SYMBOL(drm_dp_mst_put_port_malloc); #if IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS) #define STACK_DEPTH 8 static noinline void __topology_ref_save(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_topology_ref_history *history, enum drm_dp_mst_topology_ref_type type) { struct drm_dp_mst_topology_ref_entry *entry = NULL; depot_stack_handle_t backtrace; ulong stack_entries[STACK_DEPTH]; uint n; int i; n = stack_trace_save(stack_entries, ARRAY_SIZE(stack_entries), 1); backtrace = stack_depot_save(stack_entries, n, GFP_KERNEL); if (!backtrace) return; /* Try to find an existing entry for this backtrace */ for (i = 0; i < history->len; i++) { if (history->entries[i].backtrace == backtrace) { entry = &history->entries[i]; break; } } /* Otherwise add one */ if (!entry) { struct drm_dp_mst_topology_ref_entry *new; int new_len = history->len + 1; new = krealloc(history->entries, sizeof(*new) * new_len, GFP_KERNEL); if (!new) return; entry = &new[history->len]; history->len = new_len; history->entries = new; entry->backtrace = backtrace; entry->type = type; entry->count = 0; } entry->count++; entry->ts_nsec = ktime_get_ns(); } static int topology_ref_history_cmp(const void *a, const void *b) { const struct drm_dp_mst_topology_ref_entry *entry_a = a, *entry_b = b; if (entry_a->ts_nsec > entry_b->ts_nsec) return 1; else if (entry_a->ts_nsec < entry_b->ts_nsec) return -1; else return 0; } static inline const char * topology_ref_type_to_str(enum drm_dp_mst_topology_ref_type type) { if (type == DRM_DP_MST_TOPOLOGY_REF_GET) return "get"; else return "put"; } static void __dump_topology_ref_history(struct drm_dp_mst_topology_ref_history *history, void *ptr, const char *type_str) { struct drm_printer p = drm_debug_printer(DBG_PREFIX); char *buf = kzalloc(PAGE_SIZE, GFP_KERNEL); int i; if (!buf) return; if (!history->len) goto out; /* First, sort the list so that it goes from oldest to newest * reference entry */ sort(history->entries, history->len, sizeof(*history->entries), topology_ref_history_cmp, NULL); drm_printf(&p, "%s (%p) topology count reached 0, dumping history:\n", type_str, ptr); for (i = 0; i < history->len; i++) { const struct drm_dp_mst_topology_ref_entry *entry = &history->entries[i]; ulong *entries; uint nr_entries; u64 ts_nsec = entry->ts_nsec; u32 rem_nsec = do_div(ts_nsec, 1000000000); nr_entries = stack_depot_fetch(entry->backtrace, &entries); stack_trace_snprint(buf, PAGE_SIZE, entries, nr_entries, 4); drm_printf(&p, " %d %ss (last at %5llu.%06u):\n%s", entry->count, topology_ref_type_to_str(entry->type), ts_nsec, rem_nsec / 1000, buf); } /* Now free the history, since this is the only time we expose it */ kfree(history->entries); out: kfree(buf); } static __always_inline void drm_dp_mst_dump_mstb_topology_history(struct drm_dp_mst_branch *mstb) { __dump_topology_ref_history(&mstb->topology_ref_history, mstb, "MSTB"); } static __always_inline void drm_dp_mst_dump_port_topology_history(struct drm_dp_mst_port *port) { __dump_topology_ref_history(&port->topology_ref_history, port, "Port"); } static __always_inline void save_mstb_topology_ref(struct drm_dp_mst_branch *mstb, enum drm_dp_mst_topology_ref_type type) { __topology_ref_save(mstb->mgr, &mstb->topology_ref_history, type); } static __always_inline void save_port_topology_ref(struct drm_dp_mst_port *port, enum drm_dp_mst_topology_ref_type type) { __topology_ref_save(port->mgr, &port->topology_ref_history, type); } static inline void topology_ref_history_lock(struct drm_dp_mst_topology_mgr *mgr) { mutex_lock(&mgr->topology_ref_history_lock); } static inline void topology_ref_history_unlock(struct drm_dp_mst_topology_mgr *mgr) { mutex_unlock(&mgr->topology_ref_history_lock); } #else static inline void topology_ref_history_lock(struct drm_dp_mst_topology_mgr *mgr) {} static inline void topology_ref_history_unlock(struct drm_dp_mst_topology_mgr *mgr) {} static inline void drm_dp_mst_dump_mstb_topology_history(struct drm_dp_mst_branch *mstb) {} static inline void drm_dp_mst_dump_port_topology_history(struct drm_dp_mst_port *port) {} #define save_mstb_topology_ref(mstb, type) #define save_port_topology_ref(port, type) #endif static void drm_dp_destroy_mst_branch_device(struct kref *kref) { struct drm_dp_mst_branch *mstb = container_of(kref, struct drm_dp_mst_branch, topology_kref); struct drm_dp_mst_topology_mgr *mgr = mstb->mgr; drm_dp_mst_dump_mstb_topology_history(mstb); INIT_LIST_HEAD(&mstb->destroy_next); /* * This can get called under mgr->mutex, so we need to perform the * actual destruction of the mstb in another worker */ mutex_lock(&mgr->delayed_destroy_lock); list_add(&mstb->destroy_next, &mgr->destroy_branch_device_list); mutex_unlock(&mgr->delayed_destroy_lock); schedule_work(&mgr->delayed_destroy_work); } /** * drm_dp_mst_topology_try_get_mstb() - Increment the topology refcount of a * branch device unless it's zero * @mstb: &struct drm_dp_mst_branch to increment the topology refcount of * * Attempts to grab a topology reference to @mstb, if it hasn't yet been * removed from the topology (e.g. &drm_dp_mst_branch.topology_kref has * reached 0). Holding a topology reference implies that a malloc reference * will be held to @mstb as long as the user holds the topology reference. * * Care should be taken to ensure that the user has at least one malloc * reference to @mstb. If you already have a topology reference to @mstb, you * should use drm_dp_mst_topology_get_mstb() instead. * * See also: * drm_dp_mst_topology_get_mstb() * drm_dp_mst_topology_put_mstb() * * Returns: * * 1: A topology reference was grabbed successfully * * 0: @port is no longer in the topology, no reference was grabbed */ static int __must_check drm_dp_mst_topology_try_get_mstb(struct drm_dp_mst_branch *mstb) { int ret; topology_ref_history_lock(mstb->mgr); ret = kref_get_unless_zero(&mstb->topology_kref); if (ret) { DRM_DEBUG("mstb %p (%d)\n", mstb, kref_read(&mstb->topology_kref)); save_mstb_topology_ref(mstb, DRM_DP_MST_TOPOLOGY_REF_GET); } topology_ref_history_unlock(mstb->mgr); return ret; } /** * drm_dp_mst_topology_get_mstb() - Increment the topology refcount of a * branch device * @mstb: The &struct drm_dp_mst_branch to increment the topology refcount of * * Increments &drm_dp_mst_branch.topology_refcount without checking whether or * not it's already reached 0. This is only valid to use in scenarios where * you are already guaranteed to have at least one active topology reference * to @mstb. Otherwise, drm_dp_mst_topology_try_get_mstb() must be used. * * See also: * drm_dp_mst_topology_try_get_mstb() * drm_dp_mst_topology_put_mstb() */ static void drm_dp_mst_topology_get_mstb(struct drm_dp_mst_branch *mstb) { topology_ref_history_lock(mstb->mgr); save_mstb_topology_ref(mstb, DRM_DP_MST_TOPOLOGY_REF_GET); WARN_ON(kref_read(&mstb->topology_kref) == 0); kref_get(&mstb->topology_kref); DRM_DEBUG("mstb %p (%d)\n", mstb, kref_read(&mstb->topology_kref)); topology_ref_history_unlock(mstb->mgr); } /** * drm_dp_mst_topology_put_mstb() - release a topology reference to a branch * device * @mstb: The &struct drm_dp_mst_branch to release the topology reference from * * Releases a topology reference from @mstb by decrementing * &drm_dp_mst_branch.topology_kref. * * See also: * drm_dp_mst_topology_try_get_mstb() * drm_dp_mst_topology_get_mstb() */ static void drm_dp_mst_topology_put_mstb(struct drm_dp_mst_branch *mstb) { topology_ref_history_lock(mstb->mgr); DRM_DEBUG("mstb %p (%d)\n", mstb, kref_read(&mstb->topology_kref) - 1); save_mstb_topology_ref(mstb, DRM_DP_MST_TOPOLOGY_REF_PUT); topology_ref_history_unlock(mstb->mgr); kref_put(&mstb->topology_kref, drm_dp_destroy_mst_branch_device); } static void drm_dp_destroy_port(struct kref *kref) { struct drm_dp_mst_port *port = container_of(kref, struct drm_dp_mst_port, topology_kref); struct drm_dp_mst_topology_mgr *mgr = port->mgr; drm_dp_mst_dump_port_topology_history(port); /* There's nothing that needs locking to destroy an input port yet */ if (port->input) { drm_dp_mst_put_port_malloc(port); return; } kfree(port->cached_edid); /* * we can't destroy the connector here, as we might be holding the * mode_config.mutex from an EDID retrieval */ mutex_lock(&mgr->delayed_destroy_lock); list_add(&port->next, &mgr->destroy_port_list); mutex_unlock(&mgr->delayed_destroy_lock); schedule_work(&mgr->delayed_destroy_work); } /** * drm_dp_mst_topology_try_get_port() - Increment the topology refcount of a * port unless it's zero * @port: &struct drm_dp_mst_port to increment the topology refcount of * * Attempts to grab a topology reference to @port, if it hasn't yet been * removed from the topology (e.g. &drm_dp_mst_port.topology_kref has reached * 0). Holding a topology reference implies that a malloc reference will be * held to @port as long as the user holds the topology reference. * * Care should be taken to ensure that the user has at least one malloc * reference to @port. If you already have a topology reference to @port, you * should use drm_dp_mst_topology_get_port() instead. * * See also: * drm_dp_mst_topology_get_port() * drm_dp_mst_topology_put_port() * * Returns: * * 1: A topology reference was grabbed successfully * * 0: @port is no longer in the topology, no reference was grabbed */ static int __must_check drm_dp_mst_topology_try_get_port(struct drm_dp_mst_port *port) { int ret; topology_ref_history_lock(port->mgr); ret = kref_get_unless_zero(&port->topology_kref); if (ret) { DRM_DEBUG("port %p (%d)\n", port, kref_read(&port->topology_kref)); save_port_topology_ref(port, DRM_DP_MST_TOPOLOGY_REF_GET); } topology_ref_history_unlock(port->mgr); return ret; } /** * drm_dp_mst_topology_get_port() - Increment the topology refcount of a port * @port: The &struct drm_dp_mst_port to increment the topology refcount of * * Increments &drm_dp_mst_port.topology_refcount without checking whether or * not it's already reached 0. This is only valid to use in scenarios where * you are already guaranteed to have at least one active topology reference * to @port. Otherwise, drm_dp_mst_topology_try_get_port() must be used. * * See also: * drm_dp_mst_topology_try_get_port() * drm_dp_mst_topology_put_port() */ static void drm_dp_mst_topology_get_port(struct drm_dp_mst_port *port) { topology_ref_history_lock(port->mgr); WARN_ON(kref_read(&port->topology_kref) == 0); kref_get(&port->topology_kref); DRM_DEBUG("port %p (%d)\n", port, kref_read(&port->topology_kref)); save_port_topology_ref(port, DRM_DP_MST_TOPOLOGY_REF_GET); topology_ref_history_unlock(port->mgr); } /** * drm_dp_mst_topology_put_port() - release a topology reference to a port * @port: The &struct drm_dp_mst_port to release the topology reference from * * Releases a topology reference from @port by decrementing * &drm_dp_mst_port.topology_kref. * * See also: * drm_dp_mst_topology_try_get_port() * drm_dp_mst_topology_get_port() */ static void drm_dp_mst_topology_put_port(struct drm_dp_mst_port *port) { topology_ref_history_lock(port->mgr); DRM_DEBUG("port %p (%d)\n", port, kref_read(&port->topology_kref) - 1); save_port_topology_ref(port, DRM_DP_MST_TOPOLOGY_REF_PUT); topology_ref_history_unlock(port->mgr); kref_put(&port->topology_kref, drm_dp_destroy_port); } static struct drm_dp_mst_branch * drm_dp_mst_topology_get_mstb_validated_locked(struct drm_dp_mst_branch *mstb, struct drm_dp_mst_branch *to_find) { struct drm_dp_mst_port *port; struct drm_dp_mst_branch *rmstb; if (to_find == mstb) return mstb; list_for_each_entry(port, &mstb->ports, next) { if (port->mstb) { rmstb = drm_dp_mst_topology_get_mstb_validated_locked( port->mstb, to_find); if (rmstb) return rmstb; } } return NULL; } static struct drm_dp_mst_branch * drm_dp_mst_topology_get_mstb_validated(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_branch *mstb) { struct drm_dp_mst_branch *rmstb = NULL; mutex_lock(&mgr->lock); if (mgr->mst_primary) { rmstb = drm_dp_mst_topology_get_mstb_validated_locked( mgr->mst_primary, mstb); if (rmstb && !drm_dp_mst_topology_try_get_mstb(rmstb)) rmstb = NULL; } mutex_unlock(&mgr->lock); return rmstb; } static struct drm_dp_mst_port * drm_dp_mst_topology_get_port_validated_locked(struct drm_dp_mst_branch *mstb, struct drm_dp_mst_port *to_find) { struct drm_dp_mst_port *port, *mport; list_for_each_entry(port, &mstb->ports, next) { if (port == to_find) return port; if (port->mstb) { mport = drm_dp_mst_topology_get_port_validated_locked( port->mstb, to_find); if (mport) return mport; } } return NULL; } static struct drm_dp_mst_port * drm_dp_mst_topology_get_port_validated(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port) { struct drm_dp_mst_port *rport = NULL; mutex_lock(&mgr->lock); if (mgr->mst_primary) { rport = drm_dp_mst_topology_get_port_validated_locked( mgr->mst_primary, port); if (rport && !drm_dp_mst_topology_try_get_port(rport)) rport = NULL; } mutex_unlock(&mgr->lock); return rport; } static struct drm_dp_mst_port *drm_dp_get_port(struct drm_dp_mst_branch *mstb, u8 port_num) { struct drm_dp_mst_port *port; int ret; list_for_each_entry(port, &mstb->ports, next) { if (port->port_num == port_num) { ret = drm_dp_mst_topology_try_get_port(port); return ret ? port : NULL; } } return NULL; } /* * calculate a new RAD for this MST branch device * if parent has an LCT of 2 then it has 1 nibble of RAD, * if parent has an LCT of 3 then it has 2 nibbles of RAD, */ static u8 drm_dp_calculate_rad(struct drm_dp_mst_port *port, u8 *rad) { int parent_lct = port->parent->lct; int shift = 4; int idx = (parent_lct - 1) / 2; if (parent_lct > 1) { memcpy(rad, port->parent->rad, idx + 1); shift = (parent_lct % 2) ? 4 : 0; } else rad[0] = 0; rad[idx] |= port->port_num << shift; return parent_lct + 1; } static bool drm_dp_mst_is_end_device(u8 pdt, bool mcs) { switch (pdt) { case DP_PEER_DEVICE_DP_LEGACY_CONV: case DP_PEER_DEVICE_SST_SINK: return true; case DP_PEER_DEVICE_MST_BRANCHING: /* For sst branch device */ if (!mcs) return true; return false; } return true; } static int drm_dp_port_set_pdt(struct drm_dp_mst_port *port, u8 new_pdt, bool new_mcs) { struct drm_dp_mst_topology_mgr *mgr = port->mgr; struct drm_dp_mst_branch *mstb; u8 rad[8], lct; int ret = 0; if (port->pdt == new_pdt && port->mcs == new_mcs) return 0; /* Teardown the old pdt, if there is one */ if (port->pdt != DP_PEER_DEVICE_NONE) { if (drm_dp_mst_is_end_device(port->pdt, port->mcs)) { /* * If the new PDT would also have an i2c bus, * don't bother with reregistering it */ if (new_pdt != DP_PEER_DEVICE_NONE && drm_dp_mst_is_end_device(new_pdt, new_mcs)) { port->pdt = new_pdt; port->mcs = new_mcs; return 0; } /* remove i2c over sideband */ drm_dp_mst_unregister_i2c_bus(&port->aux); } else { mutex_lock(&mgr->lock); drm_dp_mst_topology_put_mstb(port->mstb); port->mstb = NULL; mutex_unlock(&mgr->lock); } } port->pdt = new_pdt; port->mcs = new_mcs; if (port->pdt != DP_PEER_DEVICE_NONE) { if (drm_dp_mst_is_end_device(port->pdt, port->mcs)) { /* add i2c over sideband */ ret = drm_dp_mst_register_i2c_bus(&port->aux); } else { lct = drm_dp_calculate_rad(port, rad); mstb = drm_dp_add_mst_branch_device(lct, rad); if (!mstb) { ret = -ENOMEM; DRM_ERROR("Failed to create MSTB for port %p", port); goto out; } mutex_lock(&mgr->lock); port->mstb = mstb; mstb->mgr = port->mgr; mstb->port_parent = port; /* * Make sure this port's memory allocation stays * around until its child MSTB releases it */ drm_dp_mst_get_port_malloc(port); mutex_unlock(&mgr->lock); /* And make sure we send a link address for this */ ret = 1; } } out: if (ret < 0) port->pdt = DP_PEER_DEVICE_NONE; return ret; } /** * drm_dp_mst_dpcd_read() - read a series of bytes from the DPCD via sideband * @aux: Fake sideband AUX CH * @offset: address of the (first) register to read * @buffer: buffer to store the register values * @size: number of bytes in @buffer * * Performs the same functionality for remote devices via * sideband messaging as drm_dp_dpcd_read() does for local * devices via actual AUX CH. * * Return: Number of bytes read, or negative error code on failure. */ ssize_t drm_dp_mst_dpcd_read(struct drm_dp_aux *aux, unsigned int offset, void *buffer, size_t size) { struct drm_dp_mst_port *port = container_of(aux, struct drm_dp_mst_port, aux); return drm_dp_send_dpcd_read(port->mgr, port, offset, size, buffer); } /** * drm_dp_mst_dpcd_write() - write a series of bytes to the DPCD via sideband * @aux: Fake sideband AUX CH * @offset: address of the (first) register to write * @buffer: buffer containing the values to write * @size: number of bytes in @buffer * * Performs the same functionality for remote devices via * sideband messaging as drm_dp_dpcd_write() does for local * devices via actual AUX CH. * * Return: number of bytes written on success, negative error code on failure. */ ssize_t drm_dp_mst_dpcd_write(struct drm_dp_aux *aux, unsigned int offset, void *buffer, size_t size) { struct drm_dp_mst_port *port = container_of(aux, struct drm_dp_mst_port, aux); return drm_dp_send_dpcd_write(port->mgr, port, offset, size, buffer); } static int drm_dp_check_mstb_guid(struct drm_dp_mst_branch *mstb, u8 *guid) { int ret = 0; memcpy(mstb->guid, guid, 16); if (!drm_dp_validate_guid(mstb->mgr, mstb->guid)) { if (mstb->port_parent) { ret = drm_dp_send_dpcd_write(mstb->mgr, mstb->port_parent, DP_GUID, 16, mstb->guid); } else { ret = drm_dp_dpcd_write(mstb->mgr->aux, DP_GUID, mstb->guid, 16); } } if (ret < 16 && ret > 0) return -EPROTO; return ret == 16 ? 0 : ret; } static void build_mst_prop_path(const struct drm_dp_mst_branch *mstb, int pnum, char *proppath, size_t proppath_size) { int i; char temp[8]; snprintf(proppath, proppath_size, "mst:%d", mstb->mgr->conn_base_id); for (i = 0; i < (mstb->lct - 1); i++) { int shift = (i % 2) ? 0 : 4; int port_num = (mstb->rad[i / 2] >> shift) & 0xf; snprintf(temp, sizeof(temp), "-%d", port_num); strlcat(proppath, temp, proppath_size); } snprintf(temp, sizeof(temp), "-%d", pnum); strlcat(proppath, temp, proppath_size); } /** * drm_dp_mst_connector_late_register() - Late MST connector registration * @connector: The MST connector * @port: The MST port for this connector * * Helper to register the remote aux device for this MST port. Drivers should * call this from their mst connector's late_register hook to enable MST aux * devices. * * Return: 0 on success, negative error code on failure. */ int drm_dp_mst_connector_late_register(struct drm_connector *connector, struct drm_dp_mst_port *port) { DRM_DEBUG_KMS("registering %s remote bus for %s\n", port->aux.name, connector->kdev->kobj.name); port->aux.dev = connector->kdev; return drm_dp_aux_register_devnode(&port->aux); } EXPORT_SYMBOL(drm_dp_mst_connector_late_register); /** * drm_dp_mst_connector_early_unregister() - Early MST connector unregistration * @connector: The MST connector * @port: The MST port for this connector * * Helper to unregister the remote aux device for this MST port, registered by * drm_dp_mst_connector_late_register(). Drivers should call this from their mst * connector's early_unregister hook. */ void drm_dp_mst_connector_early_unregister(struct drm_connector *connector, struct drm_dp_mst_port *port) { DRM_DEBUG_KMS("unregistering %s remote bus for %s\n", port->aux.name, connector->kdev->kobj.name); drm_dp_aux_unregister_devnode(&port->aux); } EXPORT_SYMBOL(drm_dp_mst_connector_early_unregister); static void drm_dp_mst_port_add_connector(struct drm_dp_mst_branch *mstb, struct drm_dp_mst_port *port) { struct drm_dp_mst_topology_mgr *mgr = port->mgr; char proppath[255]; int ret; build_mst_prop_path(mstb, port->port_num, proppath, sizeof(proppath)); port->connector = mgr->cbs->add_connector(mgr, port, proppath); if (!port->connector) { ret = -ENOMEM; goto error; } if (port->pdt != DP_PEER_DEVICE_NONE && drm_dp_mst_is_end_device(port->pdt, port->mcs)) { port->cached_edid = drm_get_edid(port->connector, &port->aux.ddc); drm_connector_set_tile_property(port->connector); } drm_connector_register(port->connector); return; error: DRM_ERROR("Failed to create connector for port %p: %d\n", port, ret); } /* * Drop a topology reference, and unlink the port from the in-memory topology * layout */ static void drm_dp_mst_topology_unlink_port(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port) { mutex_lock(&mgr->lock); port->parent->num_ports--; list_del(&port->next); mutex_unlock(&mgr->lock); drm_dp_mst_topology_put_port(port); } static struct drm_dp_mst_port * drm_dp_mst_add_port(struct drm_device *dev, struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_branch *mstb, u8 port_number) { struct drm_dp_mst_port *port = kzalloc(sizeof(*port), GFP_KERNEL); if (!port) return NULL; kref_init(&port->topology_kref); kref_init(&port->malloc_kref); port->parent = mstb; port->port_num = port_number; port->mgr = mgr; port->aux.name = "DPMST"; port->aux.dev = dev->dev; port->aux.is_remote = true; /* initialize the MST downstream port's AUX crc work queue */ drm_dp_remote_aux_init(&port->aux); /* * Make sure the memory allocation for our parent branch stays * around until our own memory allocation is released */ drm_dp_mst_get_mstb_malloc(mstb); return port; } static int drm_dp_mst_handle_link_address_port(struct drm_dp_mst_branch *mstb, struct drm_device *dev, struct drm_dp_link_addr_reply_port *port_msg) { struct drm_dp_mst_topology_mgr *mgr = mstb->mgr; struct drm_dp_mst_port *port; int old_ddps = 0, ret; u8 new_pdt = DP_PEER_DEVICE_NONE; bool new_mcs = 0; bool created = false, send_link_addr = false, changed = false; port = drm_dp_get_port(mstb, port_msg->port_number); if (!port) { port = drm_dp_mst_add_port(dev, mgr, mstb, port_msg->port_number); if (!port) return -ENOMEM; created = true; changed = true; } else if (!port->input && port_msg->input_port && port->connector) { /* Since port->connector can't be changed here, we create a * new port if input_port changes from 0 to 1 */ drm_dp_mst_topology_unlink_port(mgr, port); drm_dp_mst_topology_put_port(port); port = drm_dp_mst_add_port(dev, mgr, mstb, port_msg->port_number); if (!port) return -ENOMEM; changed = true; created = true; } else if (port->input && !port_msg->input_port) { changed = true; } else if (port->connector) { /* We're updating a port that's exposed to userspace, so do it * under lock */ drm_modeset_lock(&mgr->base.lock, NULL); old_ddps = port->ddps; changed = port->ddps != port_msg->ddps || (port->ddps && (port->ldps != port_msg->legacy_device_plug_status || port->dpcd_rev != port_msg->dpcd_revision || port->mcs != port_msg->mcs || port->pdt != port_msg->peer_device_type || port->num_sdp_stream_sinks != port_msg->num_sdp_stream_sinks)); } port->input = port_msg->input_port; if (!port->input) new_pdt = port_msg->peer_device_type; new_mcs = port_msg->mcs; port->ddps = port_msg->ddps; port->ldps = port_msg->legacy_device_plug_status; port->dpcd_rev = port_msg->dpcd_revision; port->num_sdp_streams = port_msg->num_sdp_streams; port->num_sdp_stream_sinks = port_msg->num_sdp_stream_sinks; /* manage mstb port lists with mgr lock - take a reference for this list */ if (created) { mutex_lock(&mgr->lock); drm_dp_mst_topology_get_port(port); list_add(&port->next, &mstb->ports); mstb->num_ports++; mutex_unlock(&mgr->lock); } /* * Reprobe PBN caps on both hotplug, and when re-probing the link * for our parent mstb */ if (old_ddps != port->ddps || !created) { if (port->ddps && !port->input) { ret = drm_dp_send_enum_path_resources(mgr, mstb, port); if (ret == 1) changed = true; } else { port->full_pbn = 0; } } ret = drm_dp_port_set_pdt(port, new_pdt, new_mcs); if (ret == 1) { send_link_addr = true; } else if (ret < 0) { DRM_ERROR("Failed to change PDT on port %p: %d\n", port, ret); goto fail; } /* * If this port wasn't just created, then we're reprobing because * we're coming out of suspend. In this case, always resend the link * address if there's an MSTB on this port */ if (!created && port->pdt == DP_PEER_DEVICE_MST_BRANCHING && port->mcs) send_link_addr = true; if (port->connector) drm_modeset_unlock(&mgr->base.lock); else if (!port->input) drm_dp_mst_port_add_connector(mstb, port); if (send_link_addr && port->mstb) { ret = drm_dp_send_link_address(mgr, port->mstb); if (ret == 1) /* MSTB below us changed */ changed = true; else if (ret < 0) goto fail_put; } /* put reference to this port */ drm_dp_mst_topology_put_port(port); return changed; fail: drm_dp_mst_topology_unlink_port(mgr, port); if (port->connector) drm_modeset_unlock(&mgr->base.lock); fail_put: drm_dp_mst_topology_put_port(port); return ret; } static void drm_dp_mst_handle_conn_stat(struct drm_dp_mst_branch *mstb, struct drm_dp_connection_status_notify *conn_stat) { struct drm_dp_mst_topology_mgr *mgr = mstb->mgr; struct drm_dp_mst_port *port; int old_ddps, old_input, ret, i; u8 new_pdt; bool new_mcs; bool dowork = false, create_connector = false; port = drm_dp_get_port(mstb, conn_stat->port_number); if (!port) return; if (port->connector) { if (!port->input && conn_stat->input_port) { /* * We can't remove a connector from an already exposed * port, so just throw the port out and make sure we * reprobe the link address of it's parent MSTB */ drm_dp_mst_topology_unlink_port(mgr, port); mstb->link_address_sent = false; dowork = true; goto out; } /* Locking is only needed if the port's exposed to userspace */ drm_modeset_lock(&mgr->base.lock, NULL); } else if (port->input && !conn_stat->input_port) { create_connector = true; /* Reprobe link address so we get num_sdp_streams */ mstb->link_address_sent = false; dowork = true; } old_ddps = port->ddps; old_input = port->input; port->input = conn_stat->input_port; port->ldps = conn_stat->legacy_device_plug_status; port->ddps = conn_stat->displayport_device_plug_status; if (old_ddps != port->ddps) { if (port->ddps && !port->input) drm_dp_send_enum_path_resources(mgr, mstb, port); else port->full_pbn = 0; } new_pdt = port->input ? DP_PEER_DEVICE_NONE : conn_stat->peer_device_type; new_mcs = conn_stat->message_capability_status; ret = drm_dp_port_set_pdt(port, new_pdt, new_mcs); if (ret == 1) { dowork = true; } else if (ret < 0) { DRM_ERROR("Failed to change PDT for port %p: %d\n", port, ret); dowork = false; } if (!old_input && old_ddps != port->ddps && !port->ddps) { for (i = 0; i < mgr->max_payloads; i++) { struct drm_dp_vcpi *vcpi = mgr->proposed_vcpis[i]; struct drm_dp_mst_port *port_validated; if (!vcpi) continue; port_validated = container_of(vcpi, struct drm_dp_mst_port, vcpi); port_validated = drm_dp_mst_topology_get_port_validated(mgr, port_validated); if (!port_validated) { mutex_lock(&mgr->payload_lock); vcpi->num_slots = 0; mutex_unlock(&mgr->payload_lock); } else { drm_dp_mst_topology_put_port(port_validated); } } } if (port->connector) drm_modeset_unlock(&mgr->base.lock); else if (create_connector) drm_dp_mst_port_add_connector(mstb, port); out: drm_dp_mst_topology_put_port(port); if (dowork) queue_work(system_long_wq, &mstb->mgr->work); } static struct drm_dp_mst_branch *drm_dp_get_mst_branch_device(struct drm_dp_mst_topology_mgr *mgr, u8 lct, u8 *rad) { struct drm_dp_mst_branch *mstb; struct drm_dp_mst_port *port; int i, ret; /* find the port by iterating down */ mutex_lock(&mgr->lock); mstb = mgr->mst_primary; if (!mstb) goto out; for (i = 0; i < lct - 1; i++) { int shift = (i % 2) ? 0 : 4; int port_num = (rad[i / 2] >> shift) & 0xf; list_for_each_entry(port, &mstb->ports, next) { if (port->port_num == port_num) { mstb = port->mstb; if (!mstb) { DRM_ERROR("failed to lookup MSTB with lct %d, rad %02x\n", lct, rad[0]); goto out; } break; } } } ret = drm_dp_mst_topology_try_get_mstb(mstb); if (!ret) mstb = NULL; out: mutex_unlock(&mgr->lock); return mstb; } static struct drm_dp_mst_branch *get_mst_branch_device_by_guid_helper( struct drm_dp_mst_branch *mstb, const uint8_t *guid) { struct drm_dp_mst_branch *found_mstb; struct drm_dp_mst_port *port; if (memcmp(mstb->guid, guid, 16) == 0) return mstb; list_for_each_entry(port, &mstb->ports, next) { if (!port->mstb) continue; found_mstb = get_mst_branch_device_by_guid_helper(port->mstb, guid); if (found_mstb) return found_mstb; } return NULL; } static struct drm_dp_mst_branch * drm_dp_get_mst_branch_device_by_guid(struct drm_dp_mst_topology_mgr *mgr, const uint8_t *guid) { struct drm_dp_mst_branch *mstb; int ret; /* find the port by iterating down */ mutex_lock(&mgr->lock); mstb = get_mst_branch_device_by_guid_helper(mgr->mst_primary, guid); if (mstb) { ret = drm_dp_mst_topology_try_get_mstb(mstb); if (!ret) mstb = NULL; } mutex_unlock(&mgr->lock); return mstb; } static int drm_dp_check_and_send_link_address(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_branch *mstb) { struct drm_dp_mst_port *port; int ret; bool changed = false; if (!mstb->link_address_sent) { ret = drm_dp_send_link_address(mgr, mstb); if (ret == 1) changed = true; else if (ret < 0) return ret; } list_for_each_entry(port, &mstb->ports, next) { struct drm_dp_mst_branch *mstb_child = NULL; if (port->input || !port->ddps) continue; if (port->mstb) mstb_child = drm_dp_mst_topology_get_mstb_validated( mgr, port->mstb); if (mstb_child) { ret = drm_dp_check_and_send_link_address(mgr, mstb_child); drm_dp_mst_topology_put_mstb(mstb_child); if (ret == 1) changed = true; else if (ret < 0) return ret; } } return changed; } static void drm_dp_mst_link_probe_work(struct work_struct *work) { struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, work); struct drm_device *dev = mgr->dev; struct drm_dp_mst_branch *mstb; int ret; bool clear_payload_id_table; mutex_lock(&mgr->probe_lock); mutex_lock(&mgr->lock); clear_payload_id_table = !mgr->payload_id_table_cleared; mgr->payload_id_table_cleared = true; mstb = mgr->mst_primary; if (mstb) { ret = drm_dp_mst_topology_try_get_mstb(mstb); if (!ret) mstb = NULL; } mutex_unlock(&mgr->lock); if (!mstb) { mutex_unlock(&mgr->probe_lock); return; } /* * Certain branch devices seem to incorrectly report an available_pbn * of 0 on downstream sinks, even after clearing the * DP_PAYLOAD_ALLOCATE_* registers in * drm_dp_mst_topology_mgr_set_mst(). Namely, the CableMatters USB-C * 2x DP hub. Sending a CLEAR_PAYLOAD_ID_TABLE message seems to make * things work again. */ if (clear_payload_id_table) { DRM_DEBUG_KMS("Clearing payload ID table\n"); drm_dp_send_clear_payload_id_table(mgr, mstb); } ret = drm_dp_check_and_send_link_address(mgr, mstb); drm_dp_mst_topology_put_mstb(mstb); mutex_unlock(&mgr->probe_lock); if (ret) drm_kms_helper_hotplug_event(dev); } static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr, u8 *guid) { u64 salt; if (memchr_inv(guid, 0, 16)) return true; salt = get_jiffies_64(); memcpy(&guid[0], &salt, sizeof(u64)); memcpy(&guid[8], &salt, sizeof(u64)); return false; } static void build_dpcd_read(struct drm_dp_sideband_msg_tx *msg, u8 port_num, u32 offset, u8 num_bytes) { struct drm_dp_sideband_msg_req_body req; req.req_type = DP_REMOTE_DPCD_READ; req.u.dpcd_read.port_number = port_num; req.u.dpcd_read.dpcd_address = offset; req.u.dpcd_read.num_bytes = num_bytes; drm_dp_encode_sideband_req(&req, msg); } static int drm_dp_send_sideband_msg(struct drm_dp_mst_topology_mgr *mgr, bool up, u8 *msg, int len) { int ret; int regbase = up ? DP_SIDEBAND_MSG_UP_REP_BASE : DP_SIDEBAND_MSG_DOWN_REQ_BASE; int tosend, total, offset; int retries = 0; retry: total = len; offset = 0; do { tosend = min3(mgr->max_dpcd_transaction_bytes, 16, total); ret = drm_dp_dpcd_write(mgr->aux, regbase + offset, &msg[offset], tosend); if (ret != tosend) { if (ret == -EIO && retries < 5) { retries++; goto retry; } DRM_DEBUG_KMS("failed to dpcd write %d %d\n", tosend, ret); return -EIO; } offset += tosend; total -= tosend; } while (total > 0); return 0; } static int set_hdr_from_dst_qlock(struct drm_dp_sideband_msg_hdr *hdr, struct drm_dp_sideband_msg_tx *txmsg) { struct drm_dp_mst_branch *mstb = txmsg->dst; u8 req_type; /* both msg slots are full */ if (txmsg->seqno == -1) { if (mstb->tx_slots[0] && mstb->tx_slots[1]) { DRM_DEBUG_KMS("%s: failed to find slot\n", __func__); return -EAGAIN; } if (mstb->tx_slots[0] == NULL && mstb->tx_slots[1] == NULL) { txmsg->seqno = mstb->last_seqno; mstb->last_seqno ^= 1; } else if (mstb->tx_slots[0] == NULL) txmsg->seqno = 0; else txmsg->seqno = 1; mstb->tx_slots[txmsg->seqno] = txmsg; } req_type = txmsg->msg[0] & 0x7f; if (req_type == DP_CONNECTION_STATUS_NOTIFY || req_type == DP_RESOURCE_STATUS_NOTIFY) hdr->broadcast = 1; else hdr->broadcast = 0; hdr->path_msg = txmsg->path_msg; hdr->lct = mstb->lct; hdr->lcr = mstb->lct - 1; if (mstb->lct > 1) memcpy(hdr->rad, mstb->rad, mstb->lct / 2); hdr->seqno = txmsg->seqno; return 0; } /* * process a single block of the next message in the sideband queue */ static int process_single_tx_qlock(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_sideband_msg_tx *txmsg, bool up) { u8 chunk[48]; struct drm_dp_sideband_msg_hdr hdr; int len, space, idx, tosend; int ret; memset(&hdr, 0, sizeof(struct drm_dp_sideband_msg_hdr)); if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED) { txmsg->seqno = -1; txmsg->state = DRM_DP_SIDEBAND_TX_START_SEND; } /* make hdr from dst mst - for replies use seqno otherwise assign one */ ret = set_hdr_from_dst_qlock(&hdr, txmsg); if (ret < 0) return ret; /* amount left to send in this message */ len = txmsg->cur_len - txmsg->cur_offset; /* 48 - sideband msg size - 1 byte for data CRC, x header bytes */ space = 48 - 1 - drm_dp_calc_sb_hdr_size(&hdr); tosend = min(len, space); if (len == txmsg->cur_len) hdr.somt = 1; if (space >= len) hdr.eomt = 1; hdr.msg_len = tosend + 1; drm_dp_encode_sideband_msg_hdr(&hdr, chunk, &idx); memcpy(&chunk[idx], &txmsg->msg[txmsg->cur_offset], tosend); /* add crc at end */ drm_dp_crc_sideband_chunk_req(&chunk[idx], tosend); idx += tosend + 1; ret = drm_dp_send_sideband_msg(mgr, up, chunk, idx); if (unlikely(ret) && drm_debug_enabled(DRM_UT_DP)) { struct drm_printer p = drm_debug_printer(DBG_PREFIX); drm_printf(&p, "sideband msg failed to send\n"); drm_dp_mst_dump_sideband_msg_tx(&p, txmsg); return ret; } txmsg->cur_offset += tosend; if (txmsg->cur_offset == txmsg->cur_len) { txmsg->state = DRM_DP_SIDEBAND_TX_SENT; return 1; } return 0; } static void process_single_down_tx_qlock(struct drm_dp_mst_topology_mgr *mgr) { struct drm_dp_sideband_msg_tx *txmsg; int ret; WARN_ON(!mutex_is_locked(&mgr->qlock)); /* construct a chunk from the first msg in the tx_msg queue */ if (list_empty(&mgr->tx_msg_downq)) return; txmsg = list_first_entry(&mgr->tx_msg_downq, struct drm_dp_sideband_msg_tx, next); ret = process_single_tx_qlock(mgr, txmsg, false); if (ret == 1) { /* txmsg is sent it should be in the slots now */ mgr->is_waiting_for_dwn_reply = true; list_del(&txmsg->next); } else if (ret) { DRM_DEBUG_KMS("failed to send msg in q %d\n", ret); mgr->is_waiting_for_dwn_reply = false; list_del(&txmsg->next); if (txmsg->seqno != -1) txmsg->dst->tx_slots[txmsg->seqno] = NULL; txmsg->state = DRM_DP_SIDEBAND_TX_TIMEOUT; wake_up_all(&mgr->tx_waitq); } } /* called holding qlock */ static void process_single_up_tx_qlock(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_sideband_msg_tx *txmsg) { int ret; /* construct a chunk from the first msg in the tx_msg queue */ ret = process_single_tx_qlock(mgr, txmsg, true); if (ret != 1) DRM_DEBUG_KMS("failed to send msg in q %d\n", ret); if (txmsg->seqno != -1) { WARN_ON((unsigned int)txmsg->seqno > ARRAY_SIZE(txmsg->dst->tx_slots)); txmsg->dst->tx_slots[txmsg->seqno] = NULL; } } static void drm_dp_queue_down_tx(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_sideband_msg_tx *txmsg) { mutex_lock(&mgr->qlock); list_add_tail(&txmsg->next, &mgr->tx_msg_downq); if (drm_debug_enabled(DRM_UT_DP)) { struct drm_printer p = drm_debug_printer(DBG_PREFIX); drm_dp_mst_dump_sideband_msg_tx(&p, txmsg); } if (list_is_singular(&mgr->tx_msg_downq) && !mgr->is_waiting_for_dwn_reply) process_single_down_tx_qlock(mgr); mutex_unlock(&mgr->qlock); } static void drm_dp_dump_link_address(struct drm_dp_link_address_ack_reply *reply) { struct drm_dp_link_addr_reply_port *port_reply; int i; for (i = 0; i < reply->nports; i++) { port_reply = &reply->ports[i]; DRM_DEBUG_KMS("port %d: input %d, pdt: %d, pn: %d, dpcd_rev: %02x, mcs: %d, ddps: %d, ldps %d, sdp %d/%d\n", i, port_reply->input_port, port_reply->peer_device_type, port_reply->port_number, port_reply->dpcd_revision, port_reply->mcs, port_reply->ddps, port_reply->legacy_device_plug_status, port_reply->num_sdp_streams, port_reply->num_sdp_stream_sinks); } } static int drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_branch *mstb) { struct drm_dp_sideband_msg_tx *txmsg; struct drm_dp_link_address_ack_reply *reply; struct drm_dp_mst_port *port, *tmp; int i, ret, port_mask = 0; bool changed = false; txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL); if (!txmsg) return -ENOMEM; txmsg->dst = mstb; build_link_address(txmsg); mstb->link_address_sent = true; drm_dp_queue_down_tx(mgr, txmsg); /* FIXME: Actually do some real error handling here */ ret = drm_dp_mst_wait_tx_reply(mstb, txmsg); if (ret <= 0) { DRM_ERROR("Sending link address failed with %d\n", ret); goto out; } if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) { DRM_ERROR("link address NAK received\n"); ret = -EIO; goto out; } reply = &txmsg->reply.u.link_addr; DRM_DEBUG_KMS("link address reply: %d\n", reply->nports); drm_dp_dump_link_address(reply); ret = drm_dp_check_mstb_guid(mstb, reply->guid); if (ret) { char buf[64]; drm_dp_mst_rad_to_str(mstb->rad, mstb->lct, buf, sizeof(buf)); DRM_ERROR("GUID check on %s failed: %d\n", buf, ret); goto out; } for (i = 0; i < reply->nports; i++) { port_mask |= BIT(reply->ports[i].port_number); ret = drm_dp_mst_handle_link_address_port(mstb, mgr->dev, &reply->ports[i]); if (ret == 1) changed = true; else if (ret < 0) goto out; } /* Prune any ports that are currently a part of mstb in our in-memory * topology, but were not seen in this link address. Usually this * means that they were removed while the topology was out of sync, * e.g. during suspend/resume */ mutex_lock(&mgr->lock); list_for_each_entry_safe(port, tmp, &mstb->ports, next) { if (port_mask & BIT(port->port_num)) continue; DRM_DEBUG_KMS("port %d was not in link address, removing\n", port->port_num); list_del(&port->next); drm_dp_mst_topology_put_port(port); changed = true; } mutex_unlock(&mgr->lock); out: if (ret <= 0) mstb->link_address_sent = false; kfree(txmsg); return ret < 0 ? ret : changed; } void drm_dp_send_clear_payload_id_table(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_branch *mstb) { struct drm_dp_sideband_msg_tx *txmsg; int ret; txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL); if (!txmsg) return; txmsg->dst = mstb; build_clear_payload_id_table(txmsg); drm_dp_queue_down_tx(mgr, txmsg); ret = drm_dp_mst_wait_tx_reply(mstb, txmsg); if (ret > 0 && txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) DRM_DEBUG_KMS("clear payload table id nak received\n"); kfree(txmsg); } static int drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_branch *mstb, struct drm_dp_mst_port *port) { struct drm_dp_enum_path_resources_ack_reply *path_res; struct drm_dp_sideband_msg_tx *txmsg; int ret; txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL); if (!txmsg) return -ENOMEM; txmsg->dst = mstb; build_enum_path_resources(txmsg, port->port_num); drm_dp_queue_down_tx(mgr, txmsg); ret = drm_dp_mst_wait_tx_reply(mstb, txmsg); if (ret > 0) { ret = 0; path_res = &txmsg->reply.u.path_resources; if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) { DRM_DEBUG_KMS("enum path resources nak received\n"); } else { if (port->port_num != path_res->port_number) DRM_ERROR("got incorrect port in response\n"); DRM_DEBUG_KMS("enum path resources %d: %d %d\n", path_res->port_number, path_res->full_payload_bw_number, path_res->avail_payload_bw_number); /* * If something changed, make sure we send a * hotplug */ if (port->full_pbn != path_res->full_payload_bw_number || port->fec_capable != path_res->fec_capable) ret = 1; port->full_pbn = path_res->full_payload_bw_number; port->fec_capable = path_res->fec_capable; } } kfree(txmsg); return ret; } static struct drm_dp_mst_port *drm_dp_get_last_connected_port_to_mstb(struct drm_dp_mst_branch *mstb) { if (!mstb->port_parent) return NULL; if (mstb->port_parent->mstb != mstb) return mstb->port_parent; return drm_dp_get_last_connected_port_to_mstb(mstb->port_parent->parent); } /* * Searches upwards in the topology starting from mstb to try to find the * closest available parent of mstb that's still connected to the rest of the * topology. This can be used in order to perform operations like releasing * payloads, where the branch device which owned the payload may no longer be * around and thus would require that the payload on the last living relative * be freed instead. */ static struct drm_dp_mst_branch * drm_dp_get_last_connected_port_and_mstb(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_branch *mstb, int *port_num) { struct drm_dp_mst_branch *rmstb = NULL; struct drm_dp_mst_port *found_port; mutex_lock(&mgr->lock); if (!mgr->mst_primary) goto out; do { found_port = drm_dp_get_last_connected_port_to_mstb(mstb); if (!found_port) break; if (drm_dp_mst_topology_try_get_mstb(found_port->parent)) { rmstb = found_port->parent; *port_num = found_port->port_num; } else { /* Search again, starting from this parent */ mstb = found_port->parent; } } while (!rmstb); out: mutex_unlock(&mgr->lock); return rmstb; } static int drm_dp_payload_send_msg(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port, int id, int pbn) { struct drm_dp_sideband_msg_tx *txmsg; struct drm_dp_mst_branch *mstb; int ret, port_num; u8 sinks[DRM_DP_MAX_SDP_STREAMS]; int i; port_num = port->port_num; mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent); if (!mstb) { mstb = drm_dp_get_last_connected_port_and_mstb(mgr, port->parent, &port_num); if (!mstb) return -EINVAL; } txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL); if (!txmsg) { ret = -ENOMEM; goto fail_put; } for (i = 0; i < port->num_sdp_streams; i++) sinks[i] = i; txmsg->dst = mstb; build_allocate_payload(txmsg, port_num, id, pbn, port->num_sdp_streams, sinks); drm_dp_queue_down_tx(mgr, txmsg); /* * FIXME: there is a small chance that between getting the last * connected mstb and sending the payload message, the last connected * mstb could also be removed from the topology. In the future, this * needs to be fixed by restarting the * drm_dp_get_last_connected_port_and_mstb() search in the event of a * timeout if the topology is still connected to the system. */ ret = drm_dp_mst_wait_tx_reply(mstb, txmsg); if (ret > 0) { if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) ret = -EINVAL; else ret = 0; } kfree(txmsg); fail_put: drm_dp_mst_topology_put_mstb(mstb); return ret; } int drm_dp_send_power_updown_phy(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port, bool power_up) { struct drm_dp_sideband_msg_tx *txmsg; int ret; port = drm_dp_mst_topology_get_port_validated(mgr, port); if (!port) return -EINVAL; txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL); if (!txmsg) { drm_dp_mst_topology_put_port(port); return -ENOMEM; } txmsg->dst = port->parent; build_power_updown_phy(txmsg, port->port_num, power_up); drm_dp_queue_down_tx(mgr, txmsg); ret = drm_dp_mst_wait_tx_reply(port->parent, txmsg); if (ret > 0) { if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) ret = -EINVAL; else ret = 0; } kfree(txmsg); drm_dp_mst_topology_put_port(port); return ret; } EXPORT_SYMBOL(drm_dp_send_power_updown_phy); static int drm_dp_create_payload_step1(struct drm_dp_mst_topology_mgr *mgr, int id, struct drm_dp_payload *payload) { int ret; ret = drm_dp_dpcd_write_payload(mgr, id, payload); if (ret < 0) { payload->payload_state = 0; return ret; } payload->payload_state = DP_PAYLOAD_LOCAL; return 0; } static int drm_dp_create_payload_step2(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port, int id, struct drm_dp_payload *payload) { int ret; ret = drm_dp_payload_send_msg(mgr, port, id, port->vcpi.pbn); if (ret < 0) return ret; payload->payload_state = DP_PAYLOAD_REMOTE; return ret; } static int drm_dp_destroy_payload_step1(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port, int id, struct drm_dp_payload *payload) { DRM_DEBUG_KMS("\n"); /* it's okay for these to fail */ if (port) { drm_dp_payload_send_msg(mgr, port, id, 0); } drm_dp_dpcd_write_payload(mgr, id, payload); payload->payload_state = DP_PAYLOAD_DELETE_LOCAL; return 0; } static int drm_dp_destroy_payload_step2(struct drm_dp_mst_topology_mgr *mgr, int id, struct drm_dp_payload *payload) { payload->payload_state = 0; return 0; } /** * drm_dp_update_payload_part1() - Execute payload update part 1 * @mgr: manager to use. * * This iterates over all proposed virtual channels, and tries to * allocate space in the link for them. For 0->slots transitions, * this step just writes the VCPI to the MST device. For slots->0 * transitions, this writes the updated VCPIs and removes the * remote VC payloads. * * after calling this the driver should generate ACT and payload * packets. */ int drm_dp_update_payload_part1(struct drm_dp_mst_topology_mgr *mgr) { struct drm_dp_payload req_payload; struct drm_dp_mst_port *port; int i, j; int cur_slots = 1; mutex_lock(&mgr->payload_lock); for (i = 0; i < mgr->max_payloads; i++) { struct drm_dp_vcpi *vcpi = mgr->proposed_vcpis[i]; struct drm_dp_payload *payload = &mgr->payloads[i]; bool put_port = false; /* solve the current payloads - compare to the hw ones - update the hw view */ req_payload.start_slot = cur_slots; if (vcpi) { port = container_of(vcpi, struct drm_dp_mst_port, vcpi); /* Validated ports don't matter if we're releasing * VCPI */ if (vcpi->num_slots) { port = drm_dp_mst_topology_get_port_validated( mgr, port); if (!port) { mutex_unlock(&mgr->payload_lock); return -EINVAL; } put_port = true; } req_payload.num_slots = vcpi->num_slots; req_payload.vcpi = vcpi->vcpi; } else { port = NULL; req_payload.num_slots = 0; } payload->start_slot = req_payload.start_slot; /* work out what is required to happen with this payload */ if (payload->num_slots != req_payload.num_slots) { /* need to push an update for this payload */ if (req_payload.num_slots) { drm_dp_create_payload_step1(mgr, vcpi->vcpi, &req_payload); payload->num_slots = req_payload.num_slots; payload->vcpi = req_payload.vcpi; } else if (payload->num_slots) { payload->num_slots = 0; drm_dp_destroy_payload_step1(mgr, port, payload->vcpi, payload); req_payload.payload_state = payload->payload_state; payload->start_slot = 0; } payload->payload_state = req_payload.payload_state; } cur_slots += req_payload.num_slots; if (put_port) drm_dp_mst_topology_put_port(port); } for (i = 0; i < mgr->max_payloads; /* do nothing */) { if (mgr->payloads[i].payload_state != DP_PAYLOAD_DELETE_LOCAL) { i++; continue; } DRM_DEBUG_KMS("removing payload %d\n", i); for (j = i; j < mgr->max_payloads - 1; j++) { mgr->payloads[j] = mgr->payloads[j + 1]; mgr->proposed_vcpis[j] = mgr->proposed_vcpis[j + 1]; if (mgr->proposed_vcpis[j] && mgr->proposed_vcpis[j]->num_slots) { set_bit(j + 1, &mgr->payload_mask); } else { clear_bit(j + 1, &mgr->payload_mask); } } memset(&mgr->payloads[mgr->max_payloads - 1], 0, sizeof(struct drm_dp_payload)); mgr->proposed_vcpis[mgr->max_payloads - 1] = NULL; clear_bit(mgr->max_payloads, &mgr->payload_mask); } mutex_unlock(&mgr->payload_lock); return 0; } EXPORT_SYMBOL(drm_dp_update_payload_part1); /** * drm_dp_update_payload_part2() - Execute payload update part 2 * @mgr: manager to use. * * This iterates over all proposed virtual channels, and tries to * allocate space in the link for them. For 0->slots transitions, * this step writes the remote VC payload commands. For slots->0 * this just resets some internal state. */ int drm_dp_update_payload_part2(struct drm_dp_mst_topology_mgr *mgr) { struct drm_dp_mst_port *port; int i; int ret = 0; mutex_lock(&mgr->payload_lock); for (i = 0; i < mgr->max_payloads; i++) { if (!mgr->proposed_vcpis[i]) continue; port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi); DRM_DEBUG_KMS("payload %d %d\n", i, mgr->payloads[i].payload_state); if (mgr->payloads[i].payload_state == DP_PAYLOAD_LOCAL) { ret = drm_dp_create_payload_step2(mgr, port, mgr->proposed_vcpis[i]->vcpi, &mgr->payloads[i]); } else if (mgr->payloads[i].payload_state == DP_PAYLOAD_DELETE_LOCAL) { ret = drm_dp_destroy_payload_step2(mgr, mgr->proposed_vcpis[i]->vcpi, &mgr->payloads[i]); } if (ret) { mutex_unlock(&mgr->payload_lock); return ret; } } mutex_unlock(&mgr->payload_lock); return 0; } EXPORT_SYMBOL(drm_dp_update_payload_part2); static int drm_dp_send_dpcd_read(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port, int offset, int size, u8 *bytes) { int ret = 0; struct drm_dp_sideband_msg_tx *txmsg; struct drm_dp_mst_branch *mstb; mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent); if (!mstb) return -EINVAL; txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL); if (!txmsg) { ret = -ENOMEM; goto fail_put; } build_dpcd_read(txmsg, port->port_num, offset, size); txmsg->dst = port->parent; drm_dp_queue_down_tx(mgr, txmsg); ret = drm_dp_mst_wait_tx_reply(mstb, txmsg); if (ret < 0) goto fail_free; /* DPCD read should never be NACKed */ if (txmsg->reply.reply_type == 1) { DRM_ERROR("mstb %p port %d: DPCD read on addr 0x%x for %d bytes NAKed\n", mstb, port->port_num, offset, size); ret = -EIO; goto fail_free; } if (txmsg->reply.u.remote_dpcd_read_ack.num_bytes != size) { ret = -EPROTO; goto fail_free; } ret = min_t(size_t, txmsg->reply.u.remote_dpcd_read_ack.num_bytes, size); memcpy(bytes, txmsg->reply.u.remote_dpcd_read_ack.bytes, ret); fail_free: kfree(txmsg); fail_put: drm_dp_mst_topology_put_mstb(mstb); return ret; } static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port, int offset, int size, u8 *bytes) { int ret; struct drm_dp_sideband_msg_tx *txmsg; struct drm_dp_mst_branch *mstb; mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent); if (!mstb) return -EINVAL; txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL); if (!txmsg) { ret = -ENOMEM; goto fail_put; } build_dpcd_write(txmsg, port->port_num, offset, size, bytes); txmsg->dst = mstb; drm_dp_queue_down_tx(mgr, txmsg); ret = drm_dp_mst_wait_tx_reply(mstb, txmsg); if (ret > 0) { if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) ret = -EIO; else ret = size; } kfree(txmsg); fail_put: drm_dp_mst_topology_put_mstb(mstb); return ret; } static int drm_dp_encode_up_ack_reply(struct drm_dp_sideband_msg_tx *msg, u8 req_type) { struct drm_dp_sideband_msg_reply_body reply; reply.reply_type = DP_SIDEBAND_REPLY_ACK; reply.req_type = req_type; drm_dp_encode_sideband_reply(&reply, msg); return 0; } static int drm_dp_send_up_ack_reply(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_branch *mstb, int req_type, int seqno, bool broadcast) { struct drm_dp_sideband_msg_tx *txmsg; txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL); if (!txmsg) return -ENOMEM; txmsg->dst = mstb; txmsg->seqno = seqno; drm_dp_encode_up_ack_reply(txmsg, req_type); mutex_lock(&mgr->qlock); process_single_up_tx_qlock(mgr, txmsg); mutex_unlock(&mgr->qlock); kfree(txmsg); return 0; } static int drm_dp_get_vc_payload_bw(u8 dp_link_bw, u8 dp_link_count) { if (dp_link_bw == 0 || dp_link_count == 0) DRM_DEBUG_KMS("invalid link bandwidth in DPCD: %x (link count: %d)\n", dp_link_bw, dp_link_count); return dp_link_bw * dp_link_count / 2; } /** * drm_dp_mst_topology_mgr_set_mst() - Set the MST state for a topology manager * @mgr: manager to set state for * @mst_state: true to enable MST on this connector - false to disable. * * This is called by the driver when it detects an MST capable device plugged * into a DP MST capable port, or when a DP MST capable device is unplugged. */ int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool mst_state) { int ret = 0; struct drm_dp_mst_branch *mstb = NULL; mutex_lock(&mgr->payload_lock); mutex_lock(&mgr->lock); if (mst_state == mgr->mst_state) goto out_unlock; mgr->mst_state = mst_state; /* set the device into MST mode */ if (mst_state) { struct drm_dp_payload reset_pay; WARN_ON(mgr->mst_primary); /* get dpcd info */ ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd, DP_RECEIVER_CAP_SIZE); if (ret != DP_RECEIVER_CAP_SIZE) { DRM_DEBUG_KMS("failed to read DPCD\n"); goto out_unlock; } mgr->pbn_div = drm_dp_get_vc_payload_bw(mgr->dpcd[1], mgr->dpcd[2] & DP_MAX_LANE_COUNT_MASK); if (mgr->pbn_div == 0) { ret = -EINVAL; goto out_unlock; } /* add initial branch device at LCT 1 */ mstb = drm_dp_add_mst_branch_device(1, NULL); if (mstb == NULL) { ret = -ENOMEM; goto out_unlock; } mstb->mgr = mgr; /* give this the main reference */ mgr->mst_primary = mstb; drm_dp_mst_topology_get_mstb(mgr->mst_primary); ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, DP_MST_EN | DP_UP_REQ_EN | DP_UPSTREAM_IS_SRC); if (ret < 0) goto out_unlock; reset_pay.start_slot = 0; reset_pay.num_slots = 0x3f; drm_dp_dpcd_write_payload(mgr, 0, &reset_pay); queue_work(system_long_wq, &mgr->work); ret = 0; } else { /* disable MST on the device */ mstb = mgr->mst_primary; mgr->mst_primary = NULL; /* this can fail if the device is gone */ drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, 0); ret = 0; memset(mgr->payloads, 0, mgr->max_payloads * sizeof(mgr->payloads[0])); memset(mgr->proposed_vcpis, 0, mgr->max_payloads * sizeof(mgr->proposed_vcpis[0])); mgr->payload_mask = 0; set_bit(0, &mgr->payload_mask); mgr->vcpi_mask = 0; mgr->payload_id_table_cleared = false; } out_unlock: mutex_unlock(&mgr->lock); mutex_unlock(&mgr->payload_lock); if (mstb) drm_dp_mst_topology_put_mstb(mstb); return ret; } EXPORT_SYMBOL(drm_dp_mst_topology_mgr_set_mst); static void drm_dp_mst_topology_mgr_invalidate_mstb(struct drm_dp_mst_branch *mstb) { struct drm_dp_mst_port *port; /* The link address will need to be re-sent on resume */ mstb->link_address_sent = false; list_for_each_entry(port, &mstb->ports, next) if (port->mstb) drm_dp_mst_topology_mgr_invalidate_mstb(port->mstb); } /** * drm_dp_mst_topology_mgr_suspend() - suspend the MST manager * @mgr: manager to suspend * * This function tells the MST device that we can't handle UP messages * anymore. This should stop it from sending any since we are suspended. */ void drm_dp_mst_topology_mgr_suspend(struct drm_dp_mst_topology_mgr *mgr) { mutex_lock(&mgr->lock); drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, DP_MST_EN | DP_UPSTREAM_IS_SRC); mutex_unlock(&mgr->lock); flush_work(&mgr->up_req_work); flush_work(&mgr->work); flush_work(&mgr->delayed_destroy_work); mutex_lock(&mgr->lock); if (mgr->mst_state && mgr->mst_primary) drm_dp_mst_topology_mgr_invalidate_mstb(mgr->mst_primary); mutex_unlock(&mgr->lock); } EXPORT_SYMBOL(drm_dp_mst_topology_mgr_suspend); /** * drm_dp_mst_topology_mgr_resume() - resume the MST manager * @mgr: manager to resume * @sync: whether or not to perform topology reprobing synchronously * * This will fetch DPCD and see if the device is still there, * if it is, it will rewrite the MSTM control bits, and return. * * If the device fails this returns -1, and the driver should do * a full MST reprobe, in case we were undocked. * * During system resume (where it is assumed that the driver will be calling * drm_atomic_helper_resume()) this function should be called beforehand with * @sync set to true. In contexts like runtime resume where the driver is not * expected to be calling drm_atomic_helper_resume(), this function should be * called with @sync set to false in order to avoid deadlocking. * * Returns: -1 if the MST topology was removed while we were suspended, 0 * otherwise. */ int drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr *mgr, bool sync) { int ret; u8 guid[16]; mutex_lock(&mgr->lock); if (!mgr->mst_primary) goto out_fail; ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd, DP_RECEIVER_CAP_SIZE); if (ret != DP_RECEIVER_CAP_SIZE) { DRM_DEBUG_KMS("dpcd read failed - undocked during suspend?\n"); goto out_fail; } ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, DP_MST_EN | DP_UP_REQ_EN | DP_UPSTREAM_IS_SRC); if (ret < 0) { DRM_DEBUG_KMS("mst write failed - undocked during suspend?\n"); goto out_fail; } /* Some hubs forget their guids after they resume */ ret = drm_dp_dpcd_read(mgr->aux, DP_GUID, guid, 16); if (ret != 16) { DRM_DEBUG_KMS("dpcd read failed - undocked during suspend?\n"); goto out_fail; } ret = drm_dp_check_mstb_guid(mgr->mst_primary, guid); if (ret) { DRM_DEBUG_KMS("check mstb failed - undocked during suspend?\n"); goto out_fail; } /* * For the final step of resuming the topology, we need to bring the * state of our in-memory topology back into sync with reality. So, * restart the probing process as if we're probing a new hub */ queue_work(system_long_wq, &mgr->work); mutex_unlock(&mgr->lock); if (sync) { DRM_DEBUG_KMS("Waiting for link probe work to finish re-syncing topology...\n"); flush_work(&mgr->work); } return 0; out_fail: mutex_unlock(&mgr->lock); return -1; } EXPORT_SYMBOL(drm_dp_mst_topology_mgr_resume); static bool drm_dp_get_one_sb_msg(struct drm_dp_mst_topology_mgr *mgr, bool up) { int len; u8 replyblock[32]; int replylen, curreply; int ret; struct drm_dp_sideband_msg_rx *msg; int basereg = up ? DP_SIDEBAND_MSG_UP_REQ_BASE : DP_SIDEBAND_MSG_DOWN_REP_BASE; msg = up ? &mgr->up_req_recv : &mgr->down_rep_recv; len = min(mgr->max_dpcd_transaction_bytes, 16); ret = drm_dp_dpcd_read(mgr->aux, basereg, replyblock, len); if (ret != len) { DRM_DEBUG_KMS("failed to read DPCD down rep %d %d\n", len, ret); return false; } ret = drm_dp_sideband_msg_build(msg, replyblock, len, true); if (!ret) { DRM_DEBUG_KMS("sideband msg build failed %d\n", replyblock[0]); return false; } replylen = msg->curchunk_len + msg->curchunk_hdrlen; replylen -= len; curreply = len; while (replylen > 0) { len = min3(replylen, mgr->max_dpcd_transaction_bytes, 16); ret = drm_dp_dpcd_read(mgr->aux, basereg + curreply, replyblock, len); if (ret != len) { DRM_DEBUG_KMS("failed to read a chunk (len %d, ret %d)\n", len, ret); return false; } ret = drm_dp_sideband_msg_build(msg, replyblock, len, false); if (!ret) { DRM_DEBUG_KMS("failed to build sideband msg\n"); return false; } curreply += len; replylen -= len; } return true; } static int drm_dp_mst_handle_down_rep(struct drm_dp_mst_topology_mgr *mgr) { struct drm_dp_sideband_msg_tx *txmsg; struct drm_dp_mst_branch *mstb; struct drm_dp_sideband_msg_hdr *hdr = &mgr->down_rep_recv.initial_hdr; int slot = -1; if (!drm_dp_get_one_sb_msg(mgr, false)) goto clear_down_rep_recv; if (!mgr->down_rep_recv.have_eomt) return 0; mstb = drm_dp_get_mst_branch_device(mgr, hdr->lct, hdr->rad); if (!mstb) { DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", hdr->lct); goto clear_down_rep_recv; } /* find the message */ slot = hdr->seqno; mutex_lock(&mgr->qlock); txmsg = mstb->tx_slots[slot]; /* remove from slots */ mutex_unlock(&mgr->qlock); if (!txmsg) { DRM_DEBUG_KMS("Got MST reply with no msg %p %d %d %02x %02x\n", mstb, hdr->seqno, hdr->lct, hdr->rad[0], mgr->down_rep_recv.msg[0]); goto no_msg; } drm_dp_sideband_parse_reply(&mgr->down_rep_recv, &txmsg->reply); if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) DRM_DEBUG_KMS("Got NAK reply: req 0x%02x (%s), reason 0x%02x (%s), nak data 0x%02x\n", txmsg->reply.req_type, drm_dp_mst_req_type_str(txmsg->reply.req_type), txmsg->reply.u.nak.reason, drm_dp_mst_nak_reason_str(txmsg->reply.u.nak.reason), txmsg->reply.u.nak.nak_data); memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx)); drm_dp_mst_topology_put_mstb(mstb); mutex_lock(&mgr->qlock); txmsg->state = DRM_DP_SIDEBAND_TX_RX; mstb->tx_slots[slot] = NULL; mgr->is_waiting_for_dwn_reply = false; mutex_unlock(&mgr->qlock); wake_up_all(&mgr->tx_waitq); return 0; no_msg: drm_dp_mst_topology_put_mstb(mstb); clear_down_rep_recv: mutex_lock(&mgr->qlock); mgr->is_waiting_for_dwn_reply = false; mutex_unlock(&mgr->qlock); memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx)); return 0; } static inline bool drm_dp_mst_process_up_req(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_pending_up_req *up_req) { struct drm_dp_mst_branch *mstb = NULL; struct drm_dp_sideband_msg_req_body *msg = &up_req->msg; struct drm_dp_sideband_msg_hdr *hdr = &up_req->hdr; bool hotplug = false; if (hdr->broadcast) { const u8 *guid = NULL; if (msg->req_type == DP_CONNECTION_STATUS_NOTIFY) guid = msg->u.conn_stat.guid; else if (msg->req_type == DP_RESOURCE_STATUS_NOTIFY) guid = msg->u.resource_stat.guid; if (guid) mstb = drm_dp_get_mst_branch_device_by_guid(mgr, guid); } else { mstb = drm_dp_get_mst_branch_device(mgr, hdr->lct, hdr->rad); } if (!mstb) { DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", hdr->lct); return false; } /* TODO: Add missing handler for DP_RESOURCE_STATUS_NOTIFY events */ if (msg->req_type == DP_CONNECTION_STATUS_NOTIFY) { drm_dp_mst_handle_conn_stat(mstb, &msg->u.conn_stat); hotplug = true; } drm_dp_mst_topology_put_mstb(mstb); return hotplug; } static void drm_dp_mst_up_req_work(struct work_struct *work) { struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, up_req_work); struct drm_dp_pending_up_req *up_req; bool send_hotplug = false; mutex_lock(&mgr->probe_lock); while (true) { mutex_lock(&mgr->up_req_lock); up_req = list_first_entry_or_null(&mgr->up_req_list, struct drm_dp_pending_up_req, next); if (up_req) list_del(&up_req->next); mutex_unlock(&mgr->up_req_lock); if (!up_req) break; send_hotplug |= drm_dp_mst_process_up_req(mgr, up_req); kfree(up_req); } mutex_unlock(&mgr->probe_lock); if (send_hotplug) drm_kms_helper_hotplug_event(mgr->dev); } static int drm_dp_mst_handle_up_req(struct drm_dp_mst_topology_mgr *mgr) { struct drm_dp_sideband_msg_hdr *hdr = &mgr->up_req_recv.initial_hdr; struct drm_dp_pending_up_req *up_req; bool seqno; if (!drm_dp_get_one_sb_msg(mgr, true)) goto out; if (!mgr->up_req_recv.have_eomt) return 0; up_req = kzalloc(sizeof(*up_req), GFP_KERNEL); if (!up_req) { DRM_ERROR("Not enough memory to process MST up req\n"); return -ENOMEM; } INIT_LIST_HEAD(&up_req->next); seqno = hdr->seqno; drm_dp_sideband_parse_req(&mgr->up_req_recv, &up_req->msg); if (up_req->msg.req_type != DP_CONNECTION_STATUS_NOTIFY && up_req->msg.req_type != DP_RESOURCE_STATUS_NOTIFY) { DRM_DEBUG_KMS("Received unknown up req type, ignoring: %x\n", up_req->msg.req_type); kfree(up_req); goto out; } drm_dp_send_up_ack_reply(mgr, mgr->mst_primary, up_req->msg.req_type, seqno, false); if (up_req->msg.req_type == DP_CONNECTION_STATUS_NOTIFY) { const struct drm_dp_connection_status_notify *conn_stat = &up_req->msg.u.conn_stat; DRM_DEBUG_KMS("Got CSN: pn: %d ldps:%d ddps: %d mcs: %d ip: %d pdt: %d\n", conn_stat->port_number, conn_stat->legacy_device_plug_status, conn_stat->displayport_device_plug_status, conn_stat->message_capability_status, conn_stat->input_port, conn_stat->peer_device_type); } else if (up_req->msg.req_type == DP_RESOURCE_STATUS_NOTIFY) { const struct drm_dp_resource_status_notify *res_stat = &up_req->msg.u.resource_stat; DRM_DEBUG_KMS("Got RSN: pn: %d avail_pbn %d\n", res_stat->port_number, res_stat->available_pbn); } up_req->hdr = *hdr; mutex_lock(&mgr->up_req_lock); list_add_tail(&up_req->next, &mgr->up_req_list); mutex_unlock(&mgr->up_req_lock); queue_work(system_long_wq, &mgr->up_req_work); out: memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx)); return 0; } /** * drm_dp_mst_hpd_irq() - MST hotplug IRQ notify * @mgr: manager to notify irq for. * @esi: 4 bytes from SINK_COUNT_ESI * @handled: whether the hpd interrupt was consumed or not * * This should be called from the driver when it detects a short IRQ, * along with the value of the DEVICE_SERVICE_IRQ_VECTOR_ESI0. The * topology manager will process the sideband messages received as a result * of this. */ int drm_dp_mst_hpd_irq(struct drm_dp_mst_topology_mgr *mgr, u8 *esi, bool *handled) { int ret = 0; int sc; *handled = false; sc = esi[0] & 0x3f; if (sc != mgr->sink_count) { mgr->sink_count = sc; *handled = true; } if (esi[1] & DP_DOWN_REP_MSG_RDY) { ret = drm_dp_mst_handle_down_rep(mgr); *handled = true; } if (esi[1] & DP_UP_REQ_MSG_RDY) { ret |= drm_dp_mst_handle_up_req(mgr); *handled = true; } drm_dp_mst_kick_tx(mgr); return ret; } EXPORT_SYMBOL(drm_dp_mst_hpd_irq); /** * drm_dp_mst_detect_port() - get connection status for an MST port * @connector: DRM connector for this port * @ctx: The acquisition context to use for grabbing locks * @mgr: manager for this port * @port: pointer to a port * * This returns the current connection state for a port. */ int drm_dp_mst_detect_port(struct drm_connector *connector, struct drm_modeset_acquire_ctx *ctx, struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port) { int ret; /* we need to search for the port in the mgr in case it's gone */ port = drm_dp_mst_topology_get_port_validated(mgr, port); if (!port) return connector_status_disconnected; ret = drm_modeset_lock(&mgr->base.lock, ctx); if (ret) goto out; ret = connector_status_disconnected; if (!port->ddps) goto out; switch (port->pdt) { case DP_PEER_DEVICE_NONE: case DP_PEER_DEVICE_MST_BRANCHING: if (!port->mcs) ret = connector_status_connected; break; case DP_PEER_DEVICE_SST_SINK: ret = connector_status_connected; /* for logical ports - cache the EDID */ if (port->port_num >= 8 && !port->cached_edid) { port->cached_edid = drm_get_edid(connector, &port->aux.ddc); } break; case DP_PEER_DEVICE_DP_LEGACY_CONV: if (port->ldps) ret = connector_status_connected; break; } out: drm_dp_mst_topology_put_port(port); return ret; } EXPORT_SYMBOL(drm_dp_mst_detect_port); /** * drm_dp_mst_port_has_audio() - Check whether port has audio capability or not * @mgr: manager for this port * @port: unverified pointer to a port. * * This returns whether the port supports audio or not. */ bool drm_dp_mst_port_has_audio(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port) { bool ret = false; port = drm_dp_mst_topology_get_port_validated(mgr, port); if (!port) return ret; ret = port->has_audio; drm_dp_mst_topology_put_port(port); return ret; } EXPORT_SYMBOL(drm_dp_mst_port_has_audio); /** * drm_dp_mst_get_edid() - get EDID for an MST port * @connector: toplevel connector to get EDID for * @mgr: manager for this port * @port: unverified pointer to a port. * * This returns an EDID for the port connected to a connector, * It validates the pointer still exists so the caller doesn't require a * reference. */ struct edid *drm_dp_mst_get_edid(struct drm_connector *connector, struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port) { struct edid *edid = NULL; /* we need to search for the port in the mgr in case it's gone */ port = drm_dp_mst_topology_get_port_validated(mgr, port); if (!port) return NULL; if (port->cached_edid) edid = drm_edid_duplicate(port->cached_edid); else { edid = drm_get_edid(connector, &port->aux.ddc); } port->has_audio = drm_detect_monitor_audio(edid); drm_dp_mst_topology_put_port(port); return edid; } EXPORT_SYMBOL(drm_dp_mst_get_edid); /** * drm_dp_find_vcpi_slots() - Find VCPI slots for this PBN value * @mgr: manager to use * @pbn: payload bandwidth to convert into slots. * * Calculate the number of VCPI slots that will be required for the given PBN * value. This function is deprecated, and should not be used in atomic * drivers. * * RETURNS: * The total slots required for this port, or error. */ int drm_dp_find_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, int pbn) { int num_slots; num_slots = DIV_ROUND_UP(pbn, mgr->pbn_div); /* max. time slots - one slot for MTP header */ if (num_slots > 63) return -ENOSPC; return num_slots; } EXPORT_SYMBOL(drm_dp_find_vcpi_slots); static int drm_dp_init_vcpi(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_vcpi *vcpi, int pbn, int slots) { int ret; /* max. time slots - one slot for MTP header */ if (slots > 63) return -ENOSPC; vcpi->pbn = pbn; vcpi->aligned_pbn = slots * mgr->pbn_div; vcpi->num_slots = slots; ret = drm_dp_mst_assign_payload_id(mgr, vcpi); if (ret < 0) return ret; return 0; } /** * drm_dp_atomic_find_vcpi_slots() - Find and add VCPI slots to the state * @state: global atomic state * @mgr: MST topology manager for the port * @port: port to find vcpi slots for * @pbn: bandwidth required for the mode in PBN * @pbn_div: divider for DSC mode that takes FEC into account * * Allocates VCPI slots to @port, replacing any previous VCPI allocations it * may have had. Any atomic drivers which support MST must call this function * in their &drm_encoder_helper_funcs.atomic_check() callback to change the * current VCPI allocation for the new state, but only when * &drm_crtc_state.mode_changed or &drm_crtc_state.connectors_changed is set * to ensure compatibility with userspace applications that still use the * legacy modesetting UAPI. * * Allocations set by this function are not checked against the bandwidth * restraints of @mgr until the driver calls drm_dp_mst_atomic_check(). * * Additionally, it is OK to call this function multiple times on the same * @port as needed. It is not OK however, to call this function and * drm_dp_atomic_release_vcpi_slots() in the same atomic check phase. * * See also: * drm_dp_atomic_release_vcpi_slots() * drm_dp_mst_atomic_check() * * Returns: * Total slots in the atomic state assigned for this port, or a negative error * code if the port no longer exists */ int drm_dp_atomic_find_vcpi_slots(struct drm_atomic_state *state, struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port, int pbn, int pbn_div) { struct drm_dp_mst_topology_state *topology_state; struct drm_dp_vcpi_allocation *pos, *vcpi = NULL; int prev_slots, prev_bw, req_slots; topology_state = drm_atomic_get_mst_topology_state(state, mgr); if (IS_ERR(topology_state)) return PTR_ERR(topology_state); /* Find the current allocation for this port, if any */ list_for_each_entry(pos, &topology_state->vcpis, next) { if (pos->port == port) { vcpi = pos; prev_slots = vcpi->vcpi; prev_bw = vcpi->pbn; /* * This should never happen, unless the driver tries * releasing and allocating the same VCPI allocation, * which is an error */ if (WARN_ON(!prev_slots)) { DRM_ERROR("cannot allocate and release VCPI on [MST PORT:%p] in the same state\n", port); return -EINVAL; } break; } } if (!vcpi) { prev_slots = 0; prev_bw = 0; } if (pbn_div <= 0) pbn_div = mgr->pbn_div; req_slots = DIV_ROUND_UP(pbn, pbn_div); DRM_DEBUG_ATOMIC("[CONNECTOR:%d:%s] [MST PORT:%p] VCPI %d -> %d\n", port->connector->base.id, port->connector->name, port, prev_slots, req_slots); DRM_DEBUG_ATOMIC("[CONNECTOR:%d:%s] [MST PORT:%p] PBN %d -> %d\n", port->connector->base.id, port->connector->name, port, prev_bw, pbn); /* Add the new allocation to the state */ if (!vcpi) { vcpi = kzalloc(sizeof(*vcpi), GFP_KERNEL); if (!vcpi) return -ENOMEM; drm_dp_mst_get_port_malloc(port); vcpi->port = port; list_add(&vcpi->next, &topology_state->vcpis); } vcpi->vcpi = req_slots; vcpi->pbn = pbn; return req_slots; } EXPORT_SYMBOL(drm_dp_atomic_find_vcpi_slots); /** * drm_dp_atomic_release_vcpi_slots() - Release allocated vcpi slots * @state: global atomic state * @mgr: MST topology manager for the port * @port: The port to release the VCPI slots from * * Releases any VCPI slots that have been allocated to a port in the atomic * state. Any atomic drivers which support MST must call this function in * their &drm_connector_helper_funcs.atomic_check() callback when the * connector will no longer have VCPI allocated (e.g. because its CRTC was * removed) when it had VCPI allocated in the previous atomic state. * * It is OK to call this even if @port has been removed from the system. * Additionally, it is OK to call this function multiple times on the same * @port as needed. It is not OK however, to call this function and * drm_dp_atomic_find_vcpi_slots() on the same @port in a single atomic check * phase. * * See also: * drm_dp_atomic_find_vcpi_slots() * drm_dp_mst_atomic_check() * * Returns: * 0 if all slots for this port were added back to * &drm_dp_mst_topology_state.avail_slots or negative error code */ int drm_dp_atomic_release_vcpi_slots(struct drm_atomic_state *state, struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port) { struct drm_dp_mst_topology_state *topology_state; struct drm_dp_vcpi_allocation *pos; bool found = false; topology_state = drm_atomic_get_mst_topology_state(state, mgr); if (IS_ERR(topology_state)) return PTR_ERR(topology_state); list_for_each_entry(pos, &topology_state->vcpis, next) { if (pos->port == port) { found = true; break; } } if (WARN_ON(!found)) { DRM_ERROR("no VCPI for [MST PORT:%p] found in mst state %p\n", port, &topology_state->base); return -EINVAL; } DRM_DEBUG_ATOMIC("[MST PORT:%p] VCPI %d -> 0\n", port, pos->vcpi); if (pos->vcpi) { drm_dp_mst_put_port_malloc(port); pos->vcpi = 0; pos->pbn = 0; } return 0; } EXPORT_SYMBOL(drm_dp_atomic_release_vcpi_slots); /** * drm_dp_mst_allocate_vcpi() - Allocate a virtual channel * @mgr: manager for this port * @port: port to allocate a virtual channel for. * @pbn: payload bandwidth number to request * @slots: returned number of slots for this PBN. */ bool drm_dp_mst_allocate_vcpi(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port, int pbn, int slots) { int ret; port = drm_dp_mst_topology_get_port_validated(mgr, port); if (!port) return false; if (slots < 0) return false; if (port->vcpi.vcpi > 0) { DRM_DEBUG_KMS("payload: vcpi %d already allocated for pbn %d - requested pbn %d\n", port->vcpi.vcpi, port->vcpi.pbn, pbn); if (pbn == port->vcpi.pbn) { drm_dp_mst_topology_put_port(port); return true; } } ret = drm_dp_init_vcpi(mgr, &port->vcpi, pbn, slots); if (ret) { DRM_DEBUG_KMS("failed to init vcpi slots=%d max=63 ret=%d\n", DIV_ROUND_UP(pbn, mgr->pbn_div), ret); goto out; } DRM_DEBUG_KMS("initing vcpi for pbn=%d slots=%d\n", pbn, port->vcpi.num_slots); /* Keep port allocated until its payload has been removed */ drm_dp_mst_get_port_malloc(port); drm_dp_mst_topology_put_port(port); return true; out: return false; } EXPORT_SYMBOL(drm_dp_mst_allocate_vcpi); int drm_dp_mst_get_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port) { int slots = 0; port = drm_dp_mst_topology_get_port_validated(mgr, port); if (!port) return slots; slots = port->vcpi.num_slots; drm_dp_mst_topology_put_port(port); return slots; } EXPORT_SYMBOL(drm_dp_mst_get_vcpi_slots); /** * drm_dp_mst_reset_vcpi_slots() - Reset number of slots to 0 for VCPI * @mgr: manager for this port * @port: unverified pointer to a port. * * This just resets the number of slots for the ports VCPI for later programming. */ void drm_dp_mst_reset_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port) { /* * A port with VCPI will remain allocated until its VCPI is * released, no verified ref needed */ port->vcpi.num_slots = 0; } EXPORT_SYMBOL(drm_dp_mst_reset_vcpi_slots); /** * drm_dp_mst_deallocate_vcpi() - deallocate a VCPI * @mgr: manager for this port * @port: port to deallocate vcpi for * * This can be called unconditionally, regardless of whether * drm_dp_mst_allocate_vcpi() succeeded or not. */ void drm_dp_mst_deallocate_vcpi(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port) { if (!port->vcpi.vcpi) return; drm_dp_mst_put_payload_id(mgr, port->vcpi.vcpi); port->vcpi.num_slots = 0; port->vcpi.pbn = 0; port->vcpi.aligned_pbn = 0; port->vcpi.vcpi = 0; drm_dp_mst_put_port_malloc(port); } EXPORT_SYMBOL(drm_dp_mst_deallocate_vcpi); static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr, int id, struct drm_dp_payload *payload) { u8 payload_alloc[3], status; int ret; int retries = 0; drm_dp_dpcd_writeb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, DP_PAYLOAD_TABLE_UPDATED); payload_alloc[0] = id; payload_alloc[1] = payload->start_slot; payload_alloc[2] = payload->num_slots; ret = drm_dp_dpcd_write(mgr->aux, DP_PAYLOAD_ALLOCATE_SET, payload_alloc, 3); if (ret != 3) { DRM_DEBUG_KMS("failed to write payload allocation %d\n", ret); goto fail; } retry: ret = drm_dp_dpcd_readb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status); if (ret < 0) { DRM_DEBUG_KMS("failed to read payload table status %d\n", ret); goto fail; } if (!(status & DP_PAYLOAD_TABLE_UPDATED)) { retries++; if (retries < 20) { usleep_range(10000, 20000); goto retry; } DRM_DEBUG_KMS("status not set after read payload table status %d\n", status); ret = -EINVAL; goto fail; } ret = 0; fail: return ret; } /** * drm_dp_check_act_status() - Check ACT handled status. * @mgr: manager to use * * Check the payload status bits in the DPCD for ACT handled completion. */ int drm_dp_check_act_status(struct drm_dp_mst_topology_mgr *mgr) { u8 status; int ret; int count = 0; do { ret = drm_dp_dpcd_readb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status); if (ret < 0) { DRM_DEBUG_KMS("failed to read payload table status %d\n", ret); goto fail; } if (status & DP_PAYLOAD_ACT_HANDLED) break; count++; udelay(100); } while (count < 30); if (!(status & DP_PAYLOAD_ACT_HANDLED)) { DRM_DEBUG_KMS("failed to get ACT bit %d after %d retries\n", status, count); ret = -EINVAL; goto fail; } return 0; fail: return ret; } EXPORT_SYMBOL(drm_dp_check_act_status); /** * drm_dp_calc_pbn_mode() - Calculate the PBN for a mode. * @clock: dot clock for the mode * @bpp: bpp for the mode. * @dsc: DSC mode. If true, bpp has units of 1/16 of a bit per pixel * * This uses the formula in the spec to calculate the PBN value for a mode. */ int drm_dp_calc_pbn_mode(int clock, int bpp, bool dsc) { /* * margin 5300ppm + 300ppm ~ 0.6% as per spec, factor is 1.006 * The unit of 54/64Mbytes/sec is an arbitrary unit chosen based on * common multiplier to render an integer PBN for all link rate/lane * counts combinations * calculate * peak_kbps *= (1006/1000) * peak_kbps *= (64/54) * peak_kbps *= 8 convert to bytes * * If the bpp is in units of 1/16, further divide by 16. Put this * factor in the numerator rather than the denominator to avoid * integer overflow */ if (dsc) return DIV_ROUND_UP_ULL(mul_u32_u32(clock * (bpp / 16), 64 * 1006), 8 * 54 * 1000 * 1000); return DIV_ROUND_UP_ULL(mul_u32_u32(clock * bpp, 64 * 1006), 8 * 54 * 1000 * 1000); } EXPORT_SYMBOL(drm_dp_calc_pbn_mode); /* we want to kick the TX after we've ack the up/down IRQs. */ static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr) { queue_work(system_long_wq, &mgr->tx_work); } static void drm_dp_mst_dump_mstb(struct seq_file *m, struct drm_dp_mst_branch *mstb) { struct drm_dp_mst_port *port; int tabs = mstb->lct; char prefix[10]; int i; for (i = 0; i < tabs; i++) prefix[i] = '\t'; prefix[i] = '\0'; seq_printf(m, "%smst: %p, %d\n", prefix, mstb, mstb->num_ports); list_for_each_entry(port, &mstb->ports, next) { seq_printf(m, "%sport: %d: input: %d: pdt: %d, ddps: %d ldps: %d, sdp: %d/%d, %p, conn: %p\n", prefix, port->port_num, port->input, port->pdt, port->ddps, port->ldps, port->num_sdp_streams, port->num_sdp_stream_sinks, port, port->connector); if (port->mstb) drm_dp_mst_dump_mstb(m, port->mstb); } } #define DP_PAYLOAD_TABLE_SIZE 64 static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr, char *buf) { int i; for (i = 0; i < DP_PAYLOAD_TABLE_SIZE; i += 16) { if (drm_dp_dpcd_read(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS + i, &buf[i], 16) != 16) return false; } return true; } static void fetch_monitor_name(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port, char *name, int namelen) { struct edid *mst_edid; mst_edid = drm_dp_mst_get_edid(port->connector, mgr, port); drm_edid_get_monitor_name(mst_edid, name, namelen); } /** * drm_dp_mst_dump_topology(): dump topology to seq file. * @m: seq_file to dump output to * @mgr: manager to dump current topology for. * * helper to dump MST topology to a seq file for debugfs. */ void drm_dp_mst_dump_topology(struct seq_file *m, struct drm_dp_mst_topology_mgr *mgr) { int i; struct drm_dp_mst_port *port; mutex_lock(&mgr->lock); if (mgr->mst_primary) drm_dp_mst_dump_mstb(m, mgr->mst_primary); /* dump VCPIs */ mutex_unlock(&mgr->lock); mutex_lock(&mgr->payload_lock); seq_printf(m, "vcpi: %lx %lx %d\n", mgr->payload_mask, mgr->vcpi_mask, mgr->max_payloads); for (i = 0; i < mgr->max_payloads; i++) { if (mgr->proposed_vcpis[i]) { char name[14]; port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi); fetch_monitor_name(mgr, port, name, sizeof(name)); seq_printf(m, "vcpi %d: %d %d %d sink name: %s\n", i, port->port_num, port->vcpi.vcpi, port->vcpi.num_slots, (*name != 0) ? name : "Unknown"); } else seq_printf(m, "vcpi %d:unused\n", i); } for (i = 0; i < mgr->max_payloads; i++) { seq_printf(m, "payload %d: %d, %d, %d\n", i, mgr->payloads[i].payload_state, mgr->payloads[i].start_slot, mgr->payloads[i].num_slots); } mutex_unlock(&mgr->payload_lock); mutex_lock(&mgr->lock); if (mgr->mst_primary) { u8 buf[DP_PAYLOAD_TABLE_SIZE]; int ret; ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, buf, DP_RECEIVER_CAP_SIZE); if (ret) { seq_printf(m, "dpcd read failed\n"); goto out; } seq_printf(m, "dpcd: %*ph\n", DP_RECEIVER_CAP_SIZE, buf); ret = drm_dp_dpcd_read(mgr->aux, DP_FAUX_CAP, buf, 2); if (ret) { seq_printf(m, "faux/mst read failed\n"); goto out; } seq_printf(m, "faux/mst: %*ph\n", 2, buf); ret = drm_dp_dpcd_read(mgr->aux, DP_MSTM_CTRL, buf, 1); if (ret) { seq_printf(m, "mst ctrl read failed\n"); goto out; } seq_printf(m, "mst ctrl: %*ph\n", 1, buf); /* dump the standard OUI branch header */ ret = drm_dp_dpcd_read(mgr->aux, DP_BRANCH_OUI, buf, DP_BRANCH_OUI_HEADER_SIZE); if (ret) { seq_printf(m, "branch oui read failed\n"); goto out; } seq_printf(m, "branch oui: %*phN devid: ", 3, buf); for (i = 0x3; i < 0x8 && buf[i]; i++) seq_printf(m, "%c", buf[i]); seq_printf(m, " revision: hw: %x.%x sw: %x.%x\n", buf[0x9] >> 4, buf[0x9] & 0xf, buf[0xa], buf[0xb]); if (dump_dp_payload_table(mgr, buf)) seq_printf(m, "payload table: %*ph\n", DP_PAYLOAD_TABLE_SIZE, buf); } out: mutex_unlock(&mgr->lock); } EXPORT_SYMBOL(drm_dp_mst_dump_topology); static void drm_dp_tx_work(struct work_struct *work) { struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, tx_work); mutex_lock(&mgr->qlock); if (!list_empty(&mgr->tx_msg_downq) && !mgr->is_waiting_for_dwn_reply) process_single_down_tx_qlock(mgr); mutex_unlock(&mgr->qlock); } static inline void drm_dp_destroy_connector(struct drm_dp_mst_port *port) { if (!port->connector) return; if (port->mgr->cbs->destroy_connector) { port->mgr->cbs->destroy_connector(port->mgr, port->connector); } else { drm_connector_unregister(port->connector); drm_connector_put(port->connector); } } static inline void drm_dp_delayed_destroy_port(struct drm_dp_mst_port *port) { drm_dp_destroy_connector(port); drm_dp_port_set_pdt(port, DP_PEER_DEVICE_NONE, port->mcs); drm_dp_mst_put_port_malloc(port); } static inline void drm_dp_delayed_destroy_mstb(struct drm_dp_mst_branch *mstb) { struct drm_dp_mst_topology_mgr *mgr = mstb->mgr; struct drm_dp_mst_port *port, *tmp; bool wake_tx = false; mutex_lock(&mgr->lock); list_for_each_entry_safe(port, tmp, &mstb->ports, next) { list_del(&port->next); drm_dp_mst_topology_put_port(port); } mutex_unlock(&mgr->lock); /* drop any tx slots msg */ mutex_lock(&mstb->mgr->qlock); if (mstb->tx_slots[0]) { mstb->tx_slots[0]->state = DRM_DP_SIDEBAND_TX_TIMEOUT; mstb->tx_slots[0] = NULL; wake_tx = true; } if (mstb->tx_slots[1]) { mstb->tx_slots[1]->state = DRM_DP_SIDEBAND_TX_TIMEOUT; mstb->tx_slots[1] = NULL; wake_tx = true; } mutex_unlock(&mstb->mgr->qlock); if (wake_tx) wake_up_all(&mstb->mgr->tx_waitq); drm_dp_mst_put_mstb_malloc(mstb); } static void drm_dp_delayed_destroy_work(struct work_struct *work) { struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, delayed_destroy_work); bool send_hotplug = false, go_again; /* * Not a regular list traverse as we have to drop the destroy * connector lock before destroying the mstb/port, to avoid AB->BA * ordering between this lock and the config mutex. */ do { go_again = false; for (;;) { struct drm_dp_mst_branch *mstb; mutex_lock(&mgr->delayed_destroy_lock); mstb = list_first_entry_or_null(&mgr->destroy_branch_device_list, struct drm_dp_mst_branch, destroy_next); if (mstb) list_del(&mstb->destroy_next); mutex_unlock(&mgr->delayed_destroy_lock); if (!mstb) break; drm_dp_delayed_destroy_mstb(mstb); go_again = true; } for (;;) { struct drm_dp_mst_port *port; mutex_lock(&mgr->delayed_destroy_lock); port = list_first_entry_or_null(&mgr->destroy_port_list, struct drm_dp_mst_port, next); if (port) list_del(&port->next); mutex_unlock(&mgr->delayed_destroy_lock); if (!port) break; drm_dp_delayed_destroy_port(port); send_hotplug = true; go_again = true; } } while (go_again); if (send_hotplug) drm_kms_helper_hotplug_event(mgr->dev); } static struct drm_private_state * drm_dp_mst_duplicate_state(struct drm_private_obj *obj) { struct drm_dp_mst_topology_state *state, *old_state = to_dp_mst_topology_state(obj->state); struct drm_dp_vcpi_allocation *pos, *vcpi; state = kmemdup(old_state, sizeof(*state), GFP_KERNEL); if (!state) return NULL; __drm_atomic_helper_private_obj_duplicate_state(obj, &state->base); INIT_LIST_HEAD(&state->vcpis); list_for_each_entry(pos, &old_state->vcpis, next) { /* Prune leftover freed VCPI allocations */ if (!pos->vcpi) continue; vcpi = kmemdup(pos, sizeof(*vcpi), GFP_KERNEL); if (!vcpi) goto fail; drm_dp_mst_get_port_malloc(vcpi->port); list_add(&vcpi->next, &state->vcpis); } return &state->base; fail: list_for_each_entry_safe(pos, vcpi, &state->vcpis, next) { drm_dp_mst_put_port_malloc(pos->port); kfree(pos); } kfree(state); return NULL; } static void drm_dp_mst_destroy_state(struct drm_private_obj *obj, struct drm_private_state *state) { struct drm_dp_mst_topology_state *mst_state = to_dp_mst_topology_state(state); struct drm_dp_vcpi_allocation *pos, *tmp; list_for_each_entry_safe(pos, tmp, &mst_state->vcpis, next) { /* We only keep references to ports with non-zero VCPIs */ if (pos->vcpi) drm_dp_mst_put_port_malloc(pos->port); kfree(pos); } kfree(mst_state); } static bool drm_dp_mst_port_downstream_of_branch(struct drm_dp_mst_port *port, struct drm_dp_mst_branch *branch) { while (port->parent) { if (port->parent == branch) return true; if (port->parent->port_parent) port = port->parent->port_parent; else break; } return false; } static int drm_dp_mst_atomic_check_port_bw_limit(struct drm_dp_mst_port *port, struct drm_dp_mst_topology_state *state); static int drm_dp_mst_atomic_check_mstb_bw_limit(struct drm_dp_mst_branch *mstb, struct drm_dp_mst_topology_state *state) { struct drm_dp_vcpi_allocation *vcpi; struct drm_dp_mst_port *port; int pbn_used = 0, ret; bool found = false; /* Check that we have at least one port in our state that's downstream * of this branch, otherwise we can skip this branch */ list_for_each_entry(vcpi, &state->vcpis, next) { if (!vcpi->pbn || !drm_dp_mst_port_downstream_of_branch(vcpi->port, mstb)) continue; found = true; break; } if (!found) return 0; if (mstb->port_parent) DRM_DEBUG_ATOMIC("[MSTB:%p] [MST PORT:%p] Checking bandwidth limits on [MSTB:%p]\n", mstb->port_parent->parent, mstb->port_parent, mstb); else DRM_DEBUG_ATOMIC("[MSTB:%p] Checking bandwidth limits\n", mstb); list_for_each_entry(port, &mstb->ports, next) { ret = drm_dp_mst_atomic_check_port_bw_limit(port, state); if (ret < 0) return ret; pbn_used += ret; } return pbn_used; } static int drm_dp_mst_atomic_check_port_bw_limit(struct drm_dp_mst_port *port, struct drm_dp_mst_topology_state *state) { struct drm_dp_vcpi_allocation *vcpi; int pbn_used = 0; if (port->pdt == DP_PEER_DEVICE_NONE) return 0; if (drm_dp_mst_is_end_device(port->pdt, port->mcs)) { bool found = false; list_for_each_entry(vcpi, &state->vcpis, next) { if (vcpi->port != port) continue; if (!vcpi->pbn) return 0; found = true; break; } if (!found) return 0; /* This should never happen, as it means we tried to * set a mode before querying the full_pbn */ if (WARN_ON(!port->full_pbn)) return -EINVAL; pbn_used = vcpi->pbn; } else { pbn_used = drm_dp_mst_atomic_check_mstb_bw_limit(port->mstb, state); if (pbn_used <= 0) return pbn_used; } if (pbn_used > port->full_pbn) { DRM_DEBUG_ATOMIC("[MSTB:%p] [MST PORT:%p] required PBN of %d exceeds port limit of %d\n", port->parent, port, pbn_used, port->full_pbn); return -ENOSPC; } DRM_DEBUG_ATOMIC("[MSTB:%p] [MST PORT:%p] uses %d out of %d PBN\n", port->parent, port, pbn_used, port->full_pbn); return pbn_used; } static inline int drm_dp_mst_atomic_check_vcpi_alloc_limit(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_topology_state *mst_state) { struct drm_dp_vcpi_allocation *vcpi; int avail_slots = 63, payload_count = 0; list_for_each_entry(vcpi, &mst_state->vcpis, next) { /* Releasing VCPI is always OK-even if the port is gone */ if (!vcpi->vcpi) { DRM_DEBUG_ATOMIC("[MST PORT:%p] releases all VCPI slots\n", vcpi->port); continue; } DRM_DEBUG_ATOMIC("[MST PORT:%p] requires %d vcpi slots\n", vcpi->port, vcpi->vcpi); avail_slots -= vcpi->vcpi; if (avail_slots < 0) { DRM_DEBUG_ATOMIC("[MST PORT:%p] not enough VCPI slots in mst state %p (avail=%d)\n", vcpi->port, mst_state, avail_slots + vcpi->vcpi); return -ENOSPC; } if (++payload_count > mgr->max_payloads) { DRM_DEBUG_ATOMIC("[MST MGR:%p] state %p has too many payloads (max=%d)\n", mgr, mst_state, mgr->max_payloads); return -EINVAL; } } DRM_DEBUG_ATOMIC("[MST MGR:%p] mst state %p VCPI avail=%d used=%d\n", mgr, mst_state, avail_slots, 63 - avail_slots); return 0; } /** * drm_dp_mst_add_affected_dsc_crtcs * @state: Pointer to the new struct drm_dp_mst_topology_state * @mgr: MST topology manager * * Whenever there is a change in mst topology * DSC configuration would have to be recalculated * therefore we need to trigger modeset on all affected * CRTCs in that topology * * See also: * drm_dp_mst_atomic_enable_dsc() */ int drm_dp_mst_add_affected_dsc_crtcs(struct drm_atomic_state *state, struct drm_dp_mst_topology_mgr *mgr) { struct drm_dp_mst_topology_state *mst_state; struct drm_dp_vcpi_allocation *pos; struct drm_connector *connector; struct drm_connector_state *conn_state; struct drm_crtc *crtc; struct drm_crtc_state *crtc_state; mst_state = drm_atomic_get_mst_topology_state(state, mgr); if (IS_ERR(mst_state)) return -EINVAL; list_for_each_entry(pos, &mst_state->vcpis, next) { connector = pos->port->connector; if (!connector) return -EINVAL; conn_state = drm_atomic_get_connector_state(state, connector); if (IS_ERR(conn_state)) return PTR_ERR(conn_state); crtc = conn_state->crtc; if (WARN_ON(!crtc)) return -EINVAL; if (!drm_dp_mst_dsc_aux_for_port(pos->port)) continue; crtc_state = drm_atomic_get_crtc_state(mst_state->base.state, crtc); if (IS_ERR(crtc_state)) return PTR_ERR(crtc_state); DRM_DEBUG_ATOMIC("[MST MGR:%p] Setting mode_changed flag on CRTC %p\n", mgr, crtc); crtc_state->mode_changed = true; } return 0; } EXPORT_SYMBOL(drm_dp_mst_add_affected_dsc_crtcs); /** * drm_dp_mst_atomic_enable_dsc - Set DSC Enable Flag to On/Off * @state: Pointer to the new drm_atomic_state * @port: Pointer to the affected MST Port * @pbn: Newly recalculated bw required for link with DSC enabled * @pbn_div: Divider to calculate correct number of pbn per slot * @enable: Boolean flag to enable or disable DSC on the port * * This function enables DSC on the given Port * by recalculating its vcpi from pbn provided * and sets dsc_enable flag to keep track of which * ports have DSC enabled * */ int drm_dp_mst_atomic_enable_dsc(struct drm_atomic_state *state, struct drm_dp_mst_port *port, int pbn, int pbn_div, bool enable) { struct drm_dp_mst_topology_state *mst_state; struct drm_dp_vcpi_allocation *pos; bool found = false; int vcpi = 0; mst_state = drm_atomic_get_mst_topology_state(state, port->mgr); if (IS_ERR(mst_state)) return PTR_ERR(mst_state); list_for_each_entry(pos, &mst_state->vcpis, next) { if (pos->port == port) { found = true; break; } } if (!found) { DRM_DEBUG_ATOMIC("[MST PORT:%p] Couldn't find VCPI allocation in mst state %p\n", port, mst_state); return -EINVAL; } if (pos->dsc_enabled == enable) { DRM_DEBUG_ATOMIC("[MST PORT:%p] DSC flag is already set to %d, returning %d VCPI slots\n", port, enable, pos->vcpi); vcpi = pos->vcpi; } if (enable) { vcpi = drm_dp_atomic_find_vcpi_slots(state, port->mgr, port, pbn, pbn_div); DRM_DEBUG_ATOMIC("[MST PORT:%p] Enabling DSC flag, reallocating %d VCPI slots on the port\n", port, vcpi); if (vcpi < 0) return -EINVAL; } pos->dsc_enabled = enable; return vcpi; } EXPORT_SYMBOL(drm_dp_mst_atomic_enable_dsc); /** * drm_dp_mst_atomic_check - Check that the new state of an MST topology in an * atomic update is valid * @state: Pointer to the new &struct drm_dp_mst_topology_state * * Checks the given topology state for an atomic update to ensure that it's * valid. This includes checking whether there's enough bandwidth to support * the new VCPI allocations in the atomic update. * * Any atomic drivers supporting DP MST must make sure to call this after * checking the rest of their state in their * &drm_mode_config_funcs.atomic_check() callback. * * See also: * drm_dp_atomic_find_vcpi_slots() * drm_dp_atomic_release_vcpi_slots() * * Returns: * * 0 if the new state is valid, negative error code otherwise. */ int drm_dp_mst_atomic_check(struct drm_atomic_state *state) { struct drm_dp_mst_topology_mgr *mgr; struct drm_dp_mst_topology_state *mst_state; int i, ret = 0; for_each_new_mst_mgr_in_state(state, mgr, mst_state, i) { if (!mgr->mst_state) continue; ret = drm_dp_mst_atomic_check_vcpi_alloc_limit(mgr, mst_state); if (ret) break; mutex_lock(&mgr->lock); ret = drm_dp_mst_atomic_check_mstb_bw_limit(mgr->mst_primary, mst_state); mutex_unlock(&mgr->lock); if (ret < 0) break; else ret = 0; } return ret; } EXPORT_SYMBOL(drm_dp_mst_atomic_check); const struct drm_private_state_funcs drm_dp_mst_topology_state_funcs = { .atomic_duplicate_state = drm_dp_mst_duplicate_state, .atomic_destroy_state = drm_dp_mst_destroy_state, }; EXPORT_SYMBOL(drm_dp_mst_topology_state_funcs); /** * drm_atomic_get_mst_topology_state: get MST topology state * * @state: global atomic state * @mgr: MST topology manager, also the private object in this case * * This function wraps drm_atomic_get_priv_obj_state() passing in the MST atomic * state vtable so that the private object state returned is that of a MST * topology object. Also, drm_atomic_get_private_obj_state() expects the caller * to care of the locking, so warn if don't hold the connection_mutex. * * RETURNS: * * The MST topology state or error pointer. */ struct drm_dp_mst_topology_state *drm_atomic_get_mst_topology_state(struct drm_atomic_state *state, struct drm_dp_mst_topology_mgr *mgr) { return to_dp_mst_topology_state(drm_atomic_get_private_obj_state(state, &mgr->base)); } EXPORT_SYMBOL(drm_atomic_get_mst_topology_state); /** * drm_dp_mst_topology_mgr_init - initialise a topology manager * @mgr: manager struct to initialise * @dev: device providing this structure - for i2c addition. * @aux: DP helper aux channel to talk to this device * @max_dpcd_transaction_bytes: hw specific DPCD transaction limit * @max_payloads: maximum number of payloads this GPU can source * @conn_base_id: the connector object ID the MST device is connected to. * * Return 0 for success, or negative error code on failure */ int drm_dp_mst_topology_mgr_init(struct drm_dp_mst_topology_mgr *mgr, struct drm_device *dev, struct drm_dp_aux *aux, int max_dpcd_transaction_bytes, int max_payloads, int conn_base_id) { struct drm_dp_mst_topology_state *mst_state; mutex_init(&mgr->lock); mutex_init(&mgr->qlock); mutex_init(&mgr->payload_lock); mutex_init(&mgr->delayed_destroy_lock); mutex_init(&mgr->up_req_lock); mutex_init(&mgr->probe_lock); #if IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS) mutex_init(&mgr->topology_ref_history_lock); #endif INIT_LIST_HEAD(&mgr->tx_msg_downq); INIT_LIST_HEAD(&mgr->destroy_port_list); INIT_LIST_HEAD(&mgr->destroy_branch_device_list); INIT_LIST_HEAD(&mgr->up_req_list); INIT_WORK(&mgr->work, drm_dp_mst_link_probe_work); INIT_WORK(&mgr->tx_work, drm_dp_tx_work); INIT_WORK(&mgr->delayed_destroy_work, drm_dp_delayed_destroy_work); INIT_WORK(&mgr->up_req_work, drm_dp_mst_up_req_work); init_waitqueue_head(&mgr->tx_waitq); mgr->dev = dev; mgr->aux = aux; mgr->max_dpcd_transaction_bytes = max_dpcd_transaction_bytes; mgr->max_payloads = max_payloads; mgr->conn_base_id = conn_base_id; if (max_payloads + 1 > sizeof(mgr->payload_mask) * 8 || max_payloads + 1 > sizeof(mgr->vcpi_mask) * 8) return -EINVAL; mgr->payloads = kcalloc(max_payloads, sizeof(struct drm_dp_payload), GFP_KERNEL); if (!mgr->payloads) return -ENOMEM; mgr->proposed_vcpis = kcalloc(max_payloads, sizeof(struct drm_dp_vcpi *), GFP_KERNEL); if (!mgr->proposed_vcpis) return -ENOMEM; set_bit(0, &mgr->payload_mask); mst_state = kzalloc(sizeof(*mst_state), GFP_KERNEL); if (mst_state == NULL) return -ENOMEM; mst_state->mgr = mgr; INIT_LIST_HEAD(&mst_state->vcpis); drm_atomic_private_obj_init(dev, &mgr->base, &mst_state->base, &drm_dp_mst_topology_state_funcs); return 0; } EXPORT_SYMBOL(drm_dp_mst_topology_mgr_init); /** * drm_dp_mst_topology_mgr_destroy() - destroy topology manager. * @mgr: manager to destroy */ void drm_dp_mst_topology_mgr_destroy(struct drm_dp_mst_topology_mgr *mgr) { drm_dp_mst_topology_mgr_set_mst(mgr, false); flush_work(&mgr->work); cancel_work_sync(&mgr->delayed_destroy_work); mutex_lock(&mgr->payload_lock); kfree(mgr->payloads); mgr->payloads = NULL; kfree(mgr->proposed_vcpis); mgr->proposed_vcpis = NULL; mutex_unlock(&mgr->payload_lock); mgr->dev = NULL; mgr->aux = NULL; drm_atomic_private_obj_fini(&mgr->base); mgr->funcs = NULL; mutex_destroy(&mgr->delayed_destroy_lock); mutex_destroy(&mgr->payload_lock); mutex_destroy(&mgr->qlock); mutex_destroy(&mgr->lock); mutex_destroy(&mgr->up_req_lock); mutex_destroy(&mgr->probe_lock); #if IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS) mutex_destroy(&mgr->topology_ref_history_lock); #endif } EXPORT_SYMBOL(drm_dp_mst_topology_mgr_destroy); static bool remote_i2c_read_ok(const struct i2c_msg msgs[], int num) { int i; if (num - 1 > DP_REMOTE_I2C_READ_MAX_TRANSACTIONS) return false; for (i = 0; i < num - 1; i++) { if (msgs[i].flags & I2C_M_RD || msgs[i].len > 0xff) return false; } return msgs[num - 1].flags & I2C_M_RD && msgs[num - 1].len <= 0xff; } /* I2C device */ static int drm_dp_mst_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs, int num) { struct drm_dp_aux *aux = adapter->algo_data; struct drm_dp_mst_port *port = container_of(aux, struct drm_dp_mst_port, aux); struct drm_dp_mst_branch *mstb; struct drm_dp_mst_topology_mgr *mgr = port->mgr; unsigned int i; struct drm_dp_sideband_msg_req_body msg; struct drm_dp_sideband_msg_tx *txmsg = NULL; int ret; mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent); if (!mstb) return -EREMOTEIO; if (!remote_i2c_read_ok(msgs, num)) { DRM_DEBUG_KMS("Unsupported I2C transaction for MST device\n"); ret = -EIO; goto out; } memset(&msg, 0, sizeof(msg)); msg.req_type = DP_REMOTE_I2C_READ; msg.u.i2c_read.num_transactions = num - 1; msg.u.i2c_read.port_number = port->port_num; for (i = 0; i < num - 1; i++) { msg.u.i2c_read.transactions[i].i2c_dev_id = msgs[i].addr; msg.u.i2c_read.transactions[i].num_bytes = msgs[i].len; msg.u.i2c_read.transactions[i].bytes = msgs[i].buf; msg.u.i2c_read.transactions[i].no_stop_bit = !(msgs[i].flags & I2C_M_STOP); } msg.u.i2c_read.read_i2c_device_id = msgs[num - 1].addr; msg.u.i2c_read.num_bytes_read = msgs[num - 1].len; txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL); if (!txmsg) { ret = -ENOMEM; goto out; } txmsg->dst = mstb; drm_dp_encode_sideband_req(&msg, txmsg); drm_dp_queue_down_tx(mgr, txmsg); ret = drm_dp_mst_wait_tx_reply(mstb, txmsg); if (ret > 0) { if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) { ret = -EREMOTEIO; goto out; } if (txmsg->reply.u.remote_i2c_read_ack.num_bytes != msgs[num - 1].len) { ret = -EIO; goto out; } memcpy(msgs[num - 1].buf, txmsg->reply.u.remote_i2c_read_ack.bytes, msgs[num - 1].len); ret = num; } out: kfree(txmsg); drm_dp_mst_topology_put_mstb(mstb); return ret; } static u32 drm_dp_mst_i2c_functionality(struct i2c_adapter *adapter) { return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_SMBUS_READ_BLOCK_DATA | I2C_FUNC_SMBUS_BLOCK_PROC_CALL | I2C_FUNC_10BIT_ADDR; } static const struct i2c_algorithm drm_dp_mst_i2c_algo = { .functionality = drm_dp_mst_i2c_functionality, .master_xfer = drm_dp_mst_i2c_xfer, }; /** * drm_dp_mst_register_i2c_bus() - register an I2C adapter for I2C-over-AUX * @aux: DisplayPort AUX channel * * Returns 0 on success or a negative error code on failure. */ static int drm_dp_mst_register_i2c_bus(struct drm_dp_aux *aux) { aux->ddc.algo = &drm_dp_mst_i2c_algo; aux->ddc.algo_data = aux; aux->ddc.retries = 3; aux->ddc.class = I2C_CLASS_DDC; aux->ddc.owner = THIS_MODULE; aux->ddc.dev.parent = aux->dev; aux->ddc.dev.of_node = aux->dev->of_node; strlcpy(aux->ddc.name, aux->name ? aux->name : dev_name(aux->dev), sizeof(aux->ddc.name)); return i2c_add_adapter(&aux->ddc); } /** * drm_dp_mst_unregister_i2c_bus() - unregister an I2C-over-AUX adapter * @aux: DisplayPort AUX channel */ static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_aux *aux) { i2c_del_adapter(&aux->ddc); } /** * drm_dp_mst_is_virtual_dpcd() - Is the given port a virtual DP Peer Device * @port: The port to check * * A single physical MST hub object can be represented in the topology * by multiple branches, with virtual ports between those branches. * * As of DP1.4, An MST hub with internal (virtual) ports must expose * certain DPCD registers over those ports. See sections 2.6.1.1.1 * and 2.6.1.1.2 of Display Port specification v1.4 for details. * * May acquire mgr->lock * * Returns: * true if the port is a virtual DP peer device, false otherwise */ static bool drm_dp_mst_is_virtual_dpcd(struct drm_dp_mst_port *port) { struct drm_dp_mst_port *downstream_port; if (!port || port->dpcd_rev < DP_DPCD_REV_14) return false; /* Virtual DP Sink (Internal Display Panel) */ if (port->port_num >= 8) return true; /* DP-to-HDMI Protocol Converter */ if (port->pdt == DP_PEER_DEVICE_DP_LEGACY_CONV && !port->mcs && port->ldps) return true; /* DP-to-DP */ mutex_lock(&port->mgr->lock); if (port->pdt == DP_PEER_DEVICE_MST_BRANCHING && port->mstb && port->mstb->num_ports == 2) { list_for_each_entry(downstream_port, &port->mstb->ports, next) { if (downstream_port->pdt == DP_PEER_DEVICE_SST_SINK && !downstream_port->input) { mutex_unlock(&port->mgr->lock); return true; } } } mutex_unlock(&port->mgr->lock); return false; } /** * drm_dp_mst_dsc_aux_for_port() - Find the correct aux for DSC * @port: The port to check. A leaf of the MST tree with an attached display. * * Depending on the situation, DSC may be enabled via the endpoint aux, * the immediately upstream aux, or the connector's physical aux. * * This is both the correct aux to read DSC_CAPABILITY and the * correct aux to write DSC_ENABLED. * * This operation can be expensive (up to four aux reads), so * the caller should cache the return. * * Returns: * NULL if DSC cannot be enabled on this port, otherwise the aux device */ struct drm_dp_aux *drm_dp_mst_dsc_aux_for_port(struct drm_dp_mst_port *port) { struct drm_dp_mst_port *immediate_upstream_port; struct drm_dp_mst_port *fec_port; struct drm_dp_desc desc = { 0 }; u8 endpoint_fec; u8 endpoint_dsc; if (!port) return NULL; if (port->parent->port_parent) immediate_upstream_port = port->parent->port_parent; else immediate_upstream_port = NULL; fec_port = immediate_upstream_port; while (fec_port) { /* * Each physical link (i.e. not a virtual port) between the * output and the primary device must support FEC */ if (!drm_dp_mst_is_virtual_dpcd(fec_port) && !fec_port->fec_capable) return NULL; fec_port = fec_port->parent->port_parent; } /* DP-to-DP peer device */ if (drm_dp_mst_is_virtual_dpcd(immediate_upstream_port)) { u8 upstream_dsc; if (drm_dp_dpcd_read(&port->aux, DP_DSC_SUPPORT, &endpoint_dsc, 1) != 1) return NULL; if (drm_dp_dpcd_read(&port->aux, DP_FEC_CAPABILITY, &endpoint_fec, 1) != 1) return NULL; if (drm_dp_dpcd_read(&immediate_upstream_port->aux, DP_DSC_SUPPORT, &upstream_dsc, 1) != 1) return NULL; /* Enpoint decompression with DP-to-DP peer device */ if ((endpoint_dsc & DP_DSC_DECOMPRESSION_IS_SUPPORTED) && (endpoint_fec & DP_FEC_CAPABLE) && (upstream_dsc & 0x2) /* DSC passthrough */) return &port->aux; /* Virtual DPCD decompression with DP-to-DP peer device */ return &immediate_upstream_port->aux; } /* Virtual DPCD decompression with DP-to-HDMI or Virtual DP Sink */ if (drm_dp_mst_is_virtual_dpcd(port)) return &port->aux; /* * Synaptics quirk * Applies to ports for which: * - Physical aux has Synaptics OUI * - DPv1.4 or higher * - Port is on primary branch device * - Not a VGA adapter (DP_DWN_STRM_PORT_TYPE_ANALOG) */ if (drm_dp_read_desc(port->mgr->aux, &desc, true)) return NULL; if (drm_dp_has_quirk(&desc, 0, DP_DPCD_QUIRK_DSC_WITHOUT_VIRTUAL_DPCD) && port->mgr->dpcd[DP_DPCD_REV] >= DP_DPCD_REV_14 && port->parent == port->mgr->mst_primary) { u8 downstreamport; if (drm_dp_dpcd_read(&port->aux, DP_DOWNSTREAMPORT_PRESENT, &downstreamport, 1) < 0) return NULL; if ((downstreamport & DP_DWN_STRM_PORT_PRESENT) && ((downstreamport & DP_DWN_STRM_PORT_TYPE_MASK) != DP_DWN_STRM_PORT_TYPE_ANALOG)) return port->mgr->aux; } /* * The check below verifies if the MST sink * connected to the GPU is capable of DSC - * therefore the endpoint needs to be * both DSC and FEC capable. */ if (drm_dp_dpcd_read(&port->aux, DP_DSC_SUPPORT, &endpoint_dsc, 1) != 1) return NULL; if (drm_dp_dpcd_read(&port->aux, DP_FEC_CAPABILITY, &endpoint_fec, 1) != 1) return NULL; if ((endpoint_dsc & DP_DSC_DECOMPRESSION_IS_SUPPORTED) && (endpoint_fec & DP_FEC_CAPABLE)) return &port->aux; return NULL; } EXPORT_SYMBOL(drm_dp_mst_dsc_aux_for_port);
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