| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Alex Elder | 8044 | 100.00% | 13 | 100.00% |
| Total | 8044 | 13 |
// SPDX-License-Identifier: GPL-2.0 /* Copyright (c) 2015-2018, The Linux Foundation. All rights reserved. * Copyright (C) 2018-2020 Linaro Ltd. */ #include <linux/types.h> #include <linux/bits.h> #include <linux/bitfield.h> #include <linux/mutex.h> #include <linux/completion.h> #include <linux/io.h> #include <linux/bug.h> #include <linux/interrupt.h> #include <linux/platform_device.h> #include <linux/netdevice.h> #include "gsi.h" #include "gsi_reg.h" #include "gsi_private.h" #include "gsi_trans.h" #include "ipa_gsi.h" #include "ipa_data.h" /** * DOC: The IPA Generic Software Interface * * The generic software interface (GSI) is an integral component of the IPA, * providing a well-defined communication layer between the AP subsystem * and the IPA core. The modem uses the GSI layer as well. * * -------- --------- * | | | | * | AP +<---. .----+ Modem | * | +--. | | .->+ | * | | | | | | | | * -------- | | | | --------- * v | v | * --+-+---+-+-- * | GSI | * |-----------| * | | * | IPA | * | | * ------------- * * In the above diagram, the AP and Modem represent "execution environments" * (EEs), which are independent operating environments that use the IPA for * data transfer. * * Each EE uses a set of unidirectional GSI "channels," which allow transfer * of data to or from the IPA. A channel is implemented as a ring buffer, * with a DRAM-resident array of "transfer elements" (TREs) available to * describe transfers to or from other EEs through the IPA. A transfer * element can also contain an immediate command, requesting the IPA perform * actions other than data transfer. * * Each TRE refers to a block of data--also located DRAM. After writing one * or more TREs to a channel, the writer (either the IPA or an EE) writes a * doorbell register to inform the receiving side how many elements have * been written. * * Each channel has a GSI "event ring" associated with it. An event ring * is implemented very much like a channel ring, but is always directed from * the IPA to an EE. The IPA notifies an EE (such as the AP) about channel * events by adding an entry to the event ring associated with the channel. * The GSI then writes its doorbell for the event ring, causing the target * EE to be interrupted. Each entry in an event ring contains a pointer * to the channel TRE whose completion the event represents. * * Each TRE in a channel ring has a set of flags. One flag indicates whether * the completion of the transfer operation generates an entry (and possibly * an interrupt) in the channel's event ring. Other flags allow transfer * elements to be chained together, forming a single logical transaction. * TRE flags are used to control whether and when interrupts are generated * to signal completion of channel transfers. * * Elements in channel and event rings are completed (or consumed) strictly * in order. Completion of one entry implies the completion of all preceding * entries. A single completion interrupt can therefore communicate the * completion of many transfers. * * Note that all GSI registers are little-endian, which is the assumed * endianness of I/O space accesses. The accessor functions perform byte * swapping if needed (i.e., for a big endian CPU). */ /* Delay period for interrupt moderation (in 32KHz IPA internal timer ticks) */ #define GSI_EVT_RING_INT_MODT (32 * 1) /* 1ms under 32KHz clock */ #define GSI_CMD_TIMEOUT 5 /* seconds */ #define GSI_CHANNEL_STOP_RX_RETRIES 10 #define GSI_MHI_EVENT_ID_START 10 /* 1st reserved event id */ #define GSI_MHI_EVENT_ID_END 16 /* Last reserved event id */ #define GSI_ISR_MAX_ITER 50 /* Detect interrupt storms */ /* An entry in an event ring */ struct gsi_event { __le64 xfer_ptr; __le16 len; u8 reserved1; u8 code; __le16 reserved2; u8 type; u8 chid; }; /* Hardware values from the error log register error code field */ enum gsi_err_code { GSI_INVALID_TRE_ERR = 0x1, GSI_OUT_OF_BUFFERS_ERR = 0x2, GSI_OUT_OF_RESOURCES_ERR = 0x3, GSI_UNSUPPORTED_INTER_EE_OP_ERR = 0x4, GSI_EVT_RING_EMPTY_ERR = 0x5, GSI_NON_ALLOCATED_EVT_ACCESS_ERR = 0x6, GSI_HWO_1_ERR = 0x8, }; /* Hardware values from the error log register error type field */ enum gsi_err_type { GSI_ERR_TYPE_GLOB = 0x1, GSI_ERR_TYPE_CHAN = 0x2, GSI_ERR_TYPE_EVT = 0x3, }; /* Hardware values used when programming an event ring */ enum gsi_evt_chtype { GSI_EVT_CHTYPE_MHI_EV = 0x0, GSI_EVT_CHTYPE_XHCI_EV = 0x1, GSI_EVT_CHTYPE_GPI_EV = 0x2, GSI_EVT_CHTYPE_XDCI_EV = 0x3, }; /* Hardware values used when programming a channel */ enum gsi_channel_protocol { GSI_CHANNEL_PROTOCOL_MHI = 0x0, GSI_CHANNEL_PROTOCOL_XHCI = 0x1, GSI_CHANNEL_PROTOCOL_GPI = 0x2, GSI_CHANNEL_PROTOCOL_XDCI = 0x3, }; /* Hardware values representing an event ring immediate command opcode */ enum gsi_evt_cmd_opcode { GSI_EVT_ALLOCATE = 0x0, GSI_EVT_RESET = 0x9, GSI_EVT_DE_ALLOC = 0xa, }; /* Hardware values representing a generic immediate command opcode */ enum gsi_generic_cmd_opcode { GSI_GENERIC_HALT_CHANNEL = 0x1, GSI_GENERIC_ALLOCATE_CHANNEL = 0x2, }; /* Hardware values representing a channel immediate command opcode */ enum gsi_ch_cmd_opcode { GSI_CH_ALLOCATE = 0x0, GSI_CH_START = 0x1, GSI_CH_STOP = 0x2, GSI_CH_RESET = 0x9, GSI_CH_DE_ALLOC = 0xa, }; /** gsi_channel_scratch_gpi - GPI protocol scratch register * @max_outstanding_tre: * Defines the maximum number of TREs allowed in a single transaction * on a channel (in bytes). This determines the amount of prefetch * performed by the hardware. We configure this to equal the size of * the TLV FIFO for the channel. * @outstanding_threshold: * Defines the threshold (in bytes) determining when the sequencer * should update the channel doorbell. We configure this to equal * the size of two TREs. */ struct gsi_channel_scratch_gpi { u64 reserved1; u16 reserved2; u16 max_outstanding_tre; u16 reserved3; u16 outstanding_threshold; }; /** gsi_channel_scratch - channel scratch configuration area * * The exact interpretation of this register is protocol-specific. * We only use GPI channels; see struct gsi_channel_scratch_gpi, above. */ union gsi_channel_scratch { struct gsi_channel_scratch_gpi gpi; struct { u32 word1; u32 word2; u32 word3; u32 word4; } data; }; /* Check things that can be validated at build time. */ static void gsi_validate_build(void) { /* This is used as a divisor */ BUILD_BUG_ON(!GSI_RING_ELEMENT_SIZE); /* Code assumes the size of channel and event ring element are * the same (and fixed). Make sure the size of an event ring * element is what's expected. */ BUILD_BUG_ON(sizeof(struct gsi_event) != GSI_RING_ELEMENT_SIZE); /* Hardware requires a 2^n ring size. We ensure the number of * elements in an event ring is a power of 2 elsewhere; this * ensure the elements themselves meet the requirement. */ BUILD_BUG_ON(!is_power_of_2(GSI_RING_ELEMENT_SIZE)); /* The channel element size must fit in this field */ BUILD_BUG_ON(GSI_RING_ELEMENT_SIZE > field_max(ELEMENT_SIZE_FMASK)); /* The event ring element size must fit in this field */ BUILD_BUG_ON(GSI_RING_ELEMENT_SIZE > field_max(EV_ELEMENT_SIZE_FMASK)); } /* Return the channel id associated with a given channel */ static u32 gsi_channel_id(struct gsi_channel *channel) { return channel - &channel->gsi->channel[0]; } static void gsi_irq_ieob_enable(struct gsi *gsi, u32 evt_ring_id) { u32 val; gsi->event_enable_bitmap |= BIT(evt_ring_id); val = gsi->event_enable_bitmap; iowrite32(val, gsi->virt + GSI_CNTXT_SRC_IEOB_IRQ_MSK_OFFSET); } static void gsi_irq_ieob_disable(struct gsi *gsi, u32 evt_ring_id) { u32 val; gsi->event_enable_bitmap &= ~BIT(evt_ring_id); val = gsi->event_enable_bitmap; iowrite32(val, gsi->virt + GSI_CNTXT_SRC_IEOB_IRQ_MSK_OFFSET); } /* Enable all GSI_interrupt types */ static void gsi_irq_enable(struct gsi *gsi) { u32 val; /* We don't use inter-EE channel or event interrupts */ val = GSI_CNTXT_TYPE_IRQ_MSK_ALL; val &= ~MSK_INTER_EE_CH_CTRL_FMASK; val &= ~MSK_INTER_EE_EV_CTRL_FMASK; iowrite32(val, gsi->virt + GSI_CNTXT_TYPE_IRQ_MSK_OFFSET); val = GENMASK(gsi->channel_count - 1, 0); iowrite32(val, gsi->virt + GSI_CNTXT_SRC_CH_IRQ_MSK_OFFSET); val = GENMASK(gsi->evt_ring_count - 1, 0); iowrite32(val, gsi->virt + GSI_CNTXT_SRC_EV_CH_IRQ_MSK_OFFSET); /* Each IEOB interrupt is enabled (later) as needed by channels */ iowrite32(0, gsi->virt + GSI_CNTXT_SRC_IEOB_IRQ_MSK_OFFSET); val = GSI_CNTXT_GLOB_IRQ_ALL; iowrite32(val, gsi->virt + GSI_CNTXT_GLOB_IRQ_EN_OFFSET); /* Never enable GSI_BREAK_POINT */ val = GSI_CNTXT_GSI_IRQ_ALL & ~EN_BREAK_POINT_FMASK; iowrite32(val, gsi->virt + GSI_CNTXT_GSI_IRQ_EN_OFFSET); } /* Disable all GSI_interrupt types */ static void gsi_irq_disable(struct gsi *gsi) { iowrite32(0, gsi->virt + GSI_CNTXT_GSI_IRQ_EN_OFFSET); iowrite32(0, gsi->virt + GSI_CNTXT_GLOB_IRQ_EN_OFFSET); iowrite32(0, gsi->virt + GSI_CNTXT_SRC_IEOB_IRQ_MSK_OFFSET); iowrite32(0, gsi->virt + GSI_CNTXT_SRC_EV_CH_IRQ_MSK_OFFSET); iowrite32(0, gsi->virt + GSI_CNTXT_SRC_CH_IRQ_MSK_OFFSET); iowrite32(0, gsi->virt + GSI_CNTXT_TYPE_IRQ_MSK_OFFSET); } /* Return the virtual address associated with a ring index */ void *gsi_ring_virt(struct gsi_ring *ring, u32 index) { /* Note: index *must* be used modulo the ring count here */ return ring->virt + (index % ring->count) * GSI_RING_ELEMENT_SIZE; } /* Return the 32-bit DMA address associated with a ring index */ static u32 gsi_ring_addr(struct gsi_ring *ring, u32 index) { return (ring->addr & GENMASK(31, 0)) + index * GSI_RING_ELEMENT_SIZE; } /* Return the ring index of a 32-bit ring offset */ static u32 gsi_ring_index(struct gsi_ring *ring, u32 offset) { return (offset - gsi_ring_addr(ring, 0)) / GSI_RING_ELEMENT_SIZE; } /* Issue a GSI command by writing a value to a register, then wait for * completion to be signaled. Returns true if the command completes * or false if it times out. */ static bool gsi_command(struct gsi *gsi, u32 reg, u32 val, struct completion *completion) { reinit_completion(completion); iowrite32(val, gsi->virt + reg); return !!wait_for_completion_timeout(completion, GSI_CMD_TIMEOUT * HZ); } /* Return the hardware's notion of the current state of an event ring */ static enum gsi_evt_ring_state gsi_evt_ring_state(struct gsi *gsi, u32 evt_ring_id) { u32 val; val = ioread32(gsi->virt + GSI_EV_CH_E_CNTXT_0_OFFSET(evt_ring_id)); return u32_get_bits(val, EV_CHSTATE_FMASK); } /* Issue an event ring command and wait for it to complete */ static int evt_ring_command(struct gsi *gsi, u32 evt_ring_id, enum gsi_evt_cmd_opcode opcode) { struct gsi_evt_ring *evt_ring = &gsi->evt_ring[evt_ring_id]; struct completion *completion = &evt_ring->completion; struct device *dev = gsi->dev; u32 val; val = u32_encode_bits(evt_ring_id, EV_CHID_FMASK); val |= u32_encode_bits(opcode, EV_OPCODE_FMASK); if (gsi_command(gsi, GSI_EV_CH_CMD_OFFSET, val, completion)) return 0; /* Success! */ dev_err(dev, "GSI command %u for event ring %u timed out, state %u\n", opcode, evt_ring_id, evt_ring->state); return -ETIMEDOUT; } /* Allocate an event ring in NOT_ALLOCATED state */ static int gsi_evt_ring_alloc_command(struct gsi *gsi, u32 evt_ring_id) { struct gsi_evt_ring *evt_ring = &gsi->evt_ring[evt_ring_id]; int ret; /* Get initial event ring state */ evt_ring->state = gsi_evt_ring_state(gsi, evt_ring_id); if (evt_ring->state != GSI_EVT_RING_STATE_NOT_ALLOCATED) { dev_err(gsi->dev, "bad event ring state %u before alloc\n", evt_ring->state); return -EINVAL; } ret = evt_ring_command(gsi, evt_ring_id, GSI_EVT_ALLOCATE); if (!ret && evt_ring->state != GSI_EVT_RING_STATE_ALLOCATED) { dev_err(gsi->dev, "bad event ring state %u after alloc\n", evt_ring->state); ret = -EIO; } return ret; } /* Reset a GSI event ring in ALLOCATED or ERROR state. */ static void gsi_evt_ring_reset_command(struct gsi *gsi, u32 evt_ring_id) { struct gsi_evt_ring *evt_ring = &gsi->evt_ring[evt_ring_id]; enum gsi_evt_ring_state state = evt_ring->state; int ret; if (state != GSI_EVT_RING_STATE_ALLOCATED && state != GSI_EVT_RING_STATE_ERROR) { dev_err(gsi->dev, "bad event ring state %u before reset\n", evt_ring->state); return; } ret = evt_ring_command(gsi, evt_ring_id, GSI_EVT_RESET); if (!ret && evt_ring->state != GSI_EVT_RING_STATE_ALLOCATED) dev_err(gsi->dev, "bad event ring state %u after reset\n", evt_ring->state); } /* Issue a hardware de-allocation request for an allocated event ring */ static void gsi_evt_ring_de_alloc_command(struct gsi *gsi, u32 evt_ring_id) { struct gsi_evt_ring *evt_ring = &gsi->evt_ring[evt_ring_id]; int ret; if (evt_ring->state != GSI_EVT_RING_STATE_ALLOCATED) { dev_err(gsi->dev, "bad event ring state %u before dealloc\n", evt_ring->state); return; } ret = evt_ring_command(gsi, evt_ring_id, GSI_EVT_DE_ALLOC); if (!ret && evt_ring->state != GSI_EVT_RING_STATE_NOT_ALLOCATED) dev_err(gsi->dev, "bad event ring state %u after dealloc\n", evt_ring->state); } /* Fetch the current state of a channel from hardware */ static enum gsi_channel_state gsi_channel_state(struct gsi_channel *channel) { u32 channel_id = gsi_channel_id(channel); void *virt = channel->gsi->virt; u32 val; val = ioread32(virt + GSI_CH_C_CNTXT_0_OFFSET(channel_id)); return u32_get_bits(val, CHSTATE_FMASK); } /* Issue a channel command and wait for it to complete */ static int gsi_channel_command(struct gsi_channel *channel, enum gsi_ch_cmd_opcode opcode) { struct completion *completion = &channel->completion; u32 channel_id = gsi_channel_id(channel); struct gsi *gsi = channel->gsi; struct device *dev = gsi->dev; u32 val; val = u32_encode_bits(channel_id, CH_CHID_FMASK); val |= u32_encode_bits(opcode, CH_OPCODE_FMASK); if (gsi_command(gsi, GSI_CH_CMD_OFFSET, val, completion)) return 0; /* Success! */ dev_err(dev, "GSI command %u for channel %u timed out, state %u\n", opcode, channel_id, gsi_channel_state(channel)); return -ETIMEDOUT; } /* Allocate GSI channel in NOT_ALLOCATED state */ static int gsi_channel_alloc_command(struct gsi *gsi, u32 channel_id) { struct gsi_channel *channel = &gsi->channel[channel_id]; struct device *dev = gsi->dev; enum gsi_channel_state state; int ret; /* Get initial channel state */ state = gsi_channel_state(channel); if (state != GSI_CHANNEL_STATE_NOT_ALLOCATED) { dev_err(dev, "bad channel state %u before alloc\n", state); return -EINVAL; } ret = gsi_channel_command(channel, GSI_CH_ALLOCATE); /* Channel state will normally have been updated */ state = gsi_channel_state(channel); if (!ret && state != GSI_CHANNEL_STATE_ALLOCATED) { dev_err(dev, "bad channel state %u after alloc\n", state); ret = -EIO; } return ret; } /* Start an ALLOCATED channel */ static int gsi_channel_start_command(struct gsi_channel *channel) { struct device *dev = channel->gsi->dev; enum gsi_channel_state state; int ret; state = gsi_channel_state(channel); if (state != GSI_CHANNEL_STATE_ALLOCATED && state != GSI_CHANNEL_STATE_STOPPED) { dev_err(dev, "bad channel state %u before start\n", state); return -EINVAL; } ret = gsi_channel_command(channel, GSI_CH_START); /* Channel state will normally have been updated */ state = gsi_channel_state(channel); if (!ret && state != GSI_CHANNEL_STATE_STARTED) { dev_err(dev, "bad channel state %u after start\n", state); ret = -EIO; } return ret; } /* Stop a GSI channel in STARTED state */ static int gsi_channel_stop_command(struct gsi_channel *channel) { struct device *dev = channel->gsi->dev; enum gsi_channel_state state; int ret; state = gsi_channel_state(channel); /* Channel could have entered STOPPED state since last call * if it timed out. If so, we're done. */ if (state == GSI_CHANNEL_STATE_STOPPED) return 0; if (state != GSI_CHANNEL_STATE_STARTED && state != GSI_CHANNEL_STATE_STOP_IN_PROC) { dev_err(dev, "bad channel state %u before stop\n", state); return -EINVAL; } ret = gsi_channel_command(channel, GSI_CH_STOP); /* Channel state will normally have been updated */ state = gsi_channel_state(channel); if (ret || state == GSI_CHANNEL_STATE_STOPPED) return ret; /* We may have to try again if stop is in progress */ if (state == GSI_CHANNEL_STATE_STOP_IN_PROC) return -EAGAIN; dev_err(dev, "bad channel state %u after stop\n", state); return -EIO; } /* Reset a GSI channel in ALLOCATED or ERROR state. */ static void gsi_channel_reset_command(struct gsi_channel *channel) { struct device *dev = channel->gsi->dev; enum gsi_channel_state state; int ret; msleep(1); /* A short delay is required before a RESET command */ state = gsi_channel_state(channel); if (state != GSI_CHANNEL_STATE_STOPPED && state != GSI_CHANNEL_STATE_ERROR) { dev_err(dev, "bad channel state %u before reset\n", state); return; } ret = gsi_channel_command(channel, GSI_CH_RESET); /* Channel state will normally have been updated */ state = gsi_channel_state(channel); if (!ret && state != GSI_CHANNEL_STATE_ALLOCATED) dev_err(dev, "bad channel state %u after reset\n", state); } /* Deallocate an ALLOCATED GSI channel */ static void gsi_channel_de_alloc_command(struct gsi *gsi, u32 channel_id) { struct gsi_channel *channel = &gsi->channel[channel_id]; struct device *dev = gsi->dev; enum gsi_channel_state state; int ret; state = gsi_channel_state(channel); if (state != GSI_CHANNEL_STATE_ALLOCATED) { dev_err(dev, "bad channel state %u before dealloc\n", state); return; } ret = gsi_channel_command(channel, GSI_CH_DE_ALLOC); /* Channel state will normally have been updated */ state = gsi_channel_state(channel); if (!ret && state != GSI_CHANNEL_STATE_NOT_ALLOCATED) dev_err(dev, "bad channel state %u after dealloc\n", state); } /* Ring an event ring doorbell, reporting the last entry processed by the AP. * The index argument (modulo the ring count) is the first unfilled entry, so * we supply one less than that with the doorbell. Update the event ring * index field with the value provided. */ static void gsi_evt_ring_doorbell(struct gsi *gsi, u32 evt_ring_id, u32 index) { struct gsi_ring *ring = &gsi->evt_ring[evt_ring_id].ring; u32 val; ring->index = index; /* Next unused entry */ /* Note: index *must* be used modulo the ring count here */ val = gsi_ring_addr(ring, (index - 1) % ring->count); iowrite32(val, gsi->virt + GSI_EV_CH_E_DOORBELL_0_OFFSET(evt_ring_id)); } /* Program an event ring for use */ static void gsi_evt_ring_program(struct gsi *gsi, u32 evt_ring_id) { struct gsi_evt_ring *evt_ring = &gsi->evt_ring[evt_ring_id]; size_t size = evt_ring->ring.count * GSI_RING_ELEMENT_SIZE; u32 val; val = u32_encode_bits(GSI_EVT_CHTYPE_GPI_EV, EV_CHTYPE_FMASK); val |= EV_INTYPE_FMASK; val |= u32_encode_bits(GSI_RING_ELEMENT_SIZE, EV_ELEMENT_SIZE_FMASK); iowrite32(val, gsi->virt + GSI_EV_CH_E_CNTXT_0_OFFSET(evt_ring_id)); val = u32_encode_bits(size, EV_R_LENGTH_FMASK); iowrite32(val, gsi->virt + GSI_EV_CH_E_CNTXT_1_OFFSET(evt_ring_id)); /* The context 2 and 3 registers store the low-order and * high-order 32 bits of the address of the event ring, * respectively. */ val = evt_ring->ring.addr & GENMASK(31, 0); iowrite32(val, gsi->virt + GSI_EV_CH_E_CNTXT_2_OFFSET(evt_ring_id)); val = evt_ring->ring.addr >> 32; iowrite32(val, gsi->virt + GSI_EV_CH_E_CNTXT_3_OFFSET(evt_ring_id)); /* Enable interrupt moderation by setting the moderation delay */ val = u32_encode_bits(GSI_EVT_RING_INT_MODT, MODT_FMASK); val |= u32_encode_bits(1, MODC_FMASK); /* comes from channel */ iowrite32(val, gsi->virt + GSI_EV_CH_E_CNTXT_8_OFFSET(evt_ring_id)); /* No MSI write data, and MSI address high and low address is 0 */ iowrite32(0, gsi->virt + GSI_EV_CH_E_CNTXT_9_OFFSET(evt_ring_id)); iowrite32(0, gsi->virt + GSI_EV_CH_E_CNTXT_10_OFFSET(evt_ring_id)); iowrite32(0, gsi->virt + GSI_EV_CH_E_CNTXT_11_OFFSET(evt_ring_id)); /* We don't need to get event read pointer updates */ iowrite32(0, gsi->virt + GSI_EV_CH_E_CNTXT_12_OFFSET(evt_ring_id)); iowrite32(0, gsi->virt + GSI_EV_CH_E_CNTXT_13_OFFSET(evt_ring_id)); /* Finally, tell the hardware we've completed event 0 (arbitrary) */ gsi_evt_ring_doorbell(gsi, evt_ring_id, 0); } /* Return the last (most recent) transaction completed on a channel. */ static struct gsi_trans *gsi_channel_trans_last(struct gsi_channel *channel) { struct gsi_trans_info *trans_info = &channel->trans_info; struct gsi_trans *trans; spin_lock_bh(&trans_info->spinlock); if (!list_empty(&trans_info->complete)) trans = list_last_entry(&trans_info->complete, struct gsi_trans, links); else if (!list_empty(&trans_info->polled)) trans = list_last_entry(&trans_info->polled, struct gsi_trans, links); else trans = NULL; /* Caller will wait for this, so take a reference */ if (trans) refcount_inc(&trans->refcount); spin_unlock_bh(&trans_info->spinlock); return trans; } /* Wait for transaction activity on a channel to complete */ static void gsi_channel_trans_quiesce(struct gsi_channel *channel) { struct gsi_trans *trans; /* Get the last transaction, and wait for it to complete */ trans = gsi_channel_trans_last(channel); if (trans) { wait_for_completion(&trans->completion); gsi_trans_free(trans); } } /* Stop channel activity. Transactions may not be allocated until thawed. */ static void gsi_channel_freeze(struct gsi_channel *channel) { gsi_channel_trans_quiesce(channel); napi_disable(&channel->napi); gsi_irq_ieob_disable(channel->gsi, channel->evt_ring_id); } /* Allow transactions to be used on the channel again. */ static void gsi_channel_thaw(struct gsi_channel *channel) { gsi_irq_ieob_enable(channel->gsi, channel->evt_ring_id); napi_enable(&channel->napi); } /* Program a channel for use */ static void gsi_channel_program(struct gsi_channel *channel, bool doorbell) { size_t size = channel->tre_ring.count * GSI_RING_ELEMENT_SIZE; u32 channel_id = gsi_channel_id(channel); union gsi_channel_scratch scr = { }; struct gsi_channel_scratch_gpi *gpi; struct gsi *gsi = channel->gsi; u32 wrr_weight = 0; u32 val; /* Arbitrarily pick TRE 0 as the first channel element to use */ channel->tre_ring.index = 0; /* We program all channels to use GPI protocol */ val = u32_encode_bits(GSI_CHANNEL_PROTOCOL_GPI, CHTYPE_PROTOCOL_FMASK); if (channel->toward_ipa) val |= CHTYPE_DIR_FMASK; val |= u32_encode_bits(channel->evt_ring_id, ERINDEX_FMASK); val |= u32_encode_bits(GSI_RING_ELEMENT_SIZE, ELEMENT_SIZE_FMASK); iowrite32(val, gsi->virt + GSI_CH_C_CNTXT_0_OFFSET(channel_id)); val = u32_encode_bits(size, R_LENGTH_FMASK); iowrite32(val, gsi->virt + GSI_CH_C_CNTXT_1_OFFSET(channel_id)); /* The context 2 and 3 registers store the low-order and * high-order 32 bits of the address of the channel ring, * respectively. */ val = channel->tre_ring.addr & GENMASK(31, 0); iowrite32(val, gsi->virt + GSI_CH_C_CNTXT_2_OFFSET(channel_id)); val = channel->tre_ring.addr >> 32; iowrite32(val, gsi->virt + GSI_CH_C_CNTXT_3_OFFSET(channel_id)); /* Command channel gets low weighted round-robin priority */ if (channel->command) wrr_weight = field_max(WRR_WEIGHT_FMASK); val = u32_encode_bits(wrr_weight, WRR_WEIGHT_FMASK); /* Max prefetch is 1 segment (do not set MAX_PREFETCH_FMASK) */ /* Enable the doorbell engine if requested */ if (doorbell) val |= USE_DB_ENG_FMASK; if (!channel->use_prefetch) val |= USE_ESCAPE_BUF_ONLY_FMASK; iowrite32(val, gsi->virt + GSI_CH_C_QOS_OFFSET(channel_id)); /* Now update the scratch registers for GPI protocol */ gpi = &scr.gpi; gpi->max_outstanding_tre = gsi_channel_trans_tre_max(gsi, channel_id) * GSI_RING_ELEMENT_SIZE; gpi->outstanding_threshold = 2 * GSI_RING_ELEMENT_SIZE; val = scr.data.word1; iowrite32(val, gsi->virt + GSI_CH_C_SCRATCH_0_OFFSET(channel_id)); val = scr.data.word2; iowrite32(val, gsi->virt + GSI_CH_C_SCRATCH_1_OFFSET(channel_id)); val = scr.data.word3; iowrite32(val, gsi->virt + GSI_CH_C_SCRATCH_2_OFFSET(channel_id)); /* We must preserve the upper 16 bits of the last scratch register. * The next sequence assumes those bits remain unchanged between the * read and the write. */ val = ioread32(gsi->virt + GSI_CH_C_SCRATCH_3_OFFSET(channel_id)); val = (scr.data.word4 & GENMASK(31, 16)) | (val & GENMASK(15, 0)); iowrite32(val, gsi->virt + GSI_CH_C_SCRATCH_3_OFFSET(channel_id)); /* All done! */ } static void gsi_channel_deprogram(struct gsi_channel *channel) { /* Nothing to do */ } /* Start an allocated GSI channel */ int gsi_channel_start(struct gsi *gsi, u32 channel_id) { struct gsi_channel *channel = &gsi->channel[channel_id]; int ret; mutex_lock(&gsi->mutex); ret = gsi_channel_start_command(channel); mutex_unlock(&gsi->mutex); gsi_channel_thaw(channel); return ret; } /* Stop a started channel */ int gsi_channel_stop(struct gsi *gsi, u32 channel_id) { struct gsi_channel *channel = &gsi->channel[channel_id]; u32 retries; int ret; gsi_channel_freeze(channel); /* RX channels might require a little time to enter STOPPED state */ retries = channel->toward_ipa ? 0 : GSI_CHANNEL_STOP_RX_RETRIES; mutex_lock(&gsi->mutex); do { ret = gsi_channel_stop_command(channel); if (ret != -EAGAIN) break; msleep(1); } while (retries--); mutex_unlock(&gsi->mutex); /* Thaw the channel if we need to retry (or on error) */ if (ret) gsi_channel_thaw(channel); return ret; } /* Reset and reconfigure a channel (possibly leaving doorbell disabled) */ void gsi_channel_reset(struct gsi *gsi, u32 channel_id, bool legacy) { struct gsi_channel *channel = &gsi->channel[channel_id]; mutex_lock(&gsi->mutex); gsi_channel_reset_command(channel); /* Due to a hardware quirk we may need to reset RX channels twice. */ if (legacy && !channel->toward_ipa) gsi_channel_reset_command(channel); gsi_channel_program(channel, legacy); gsi_channel_trans_cancel_pending(channel); mutex_unlock(&gsi->mutex); } /* Stop a STARTED channel for suspend (using stop if requested) */ int gsi_channel_suspend(struct gsi *gsi, u32 channel_id, bool stop) { struct gsi_channel *channel = &gsi->channel[channel_id]; if (stop) return gsi_channel_stop(gsi, channel_id); gsi_channel_freeze(channel); return 0; } /* Resume a suspended channel (starting will be requested if STOPPED) */ int gsi_channel_resume(struct gsi *gsi, u32 channel_id, bool start) { struct gsi_channel *channel = &gsi->channel[channel_id]; if (start) return gsi_channel_start(gsi, channel_id); gsi_channel_thaw(channel); return 0; } /** * gsi_channel_tx_queued() - Report queued TX transfers for a channel * @channel: Channel for which to report * * Report to the network stack the number of bytes and transactions that * have been queued to hardware since last call. This and the next function * supply information used by the network stack for throttling. * * For each channel we track the number of transactions used and bytes of * data those transactions represent. We also track what those values are * each time this function is called. Subtracting the two tells us * the number of bytes and transactions that have been added between * successive calls. * * Calling this each time we ring the channel doorbell allows us to * provide accurate information to the network stack about how much * work we've given the hardware at any point in time. */ void gsi_channel_tx_queued(struct gsi_channel *channel) { u32 trans_count; u32 byte_count; byte_count = channel->byte_count - channel->queued_byte_count; trans_count = channel->trans_count - channel->queued_trans_count; channel->queued_byte_count = channel->byte_count; channel->queued_trans_count = channel->trans_count; ipa_gsi_channel_tx_queued(channel->gsi, gsi_channel_id(channel), trans_count, byte_count); } /** * gsi_channel_tx_update() - Report completed TX transfers * @channel: Channel that has completed transmitting packets * @trans: Last transation known to be complete * * Compute the number of transactions and bytes that have been transferred * over a TX channel since the given transaction was committed. Report this * information to the network stack. * * At the time a transaction is committed, we record its channel's * committed transaction and byte counts *in the transaction*. * Completions are signaled by the hardware with an interrupt, and * we can determine the latest completed transaction at that time. * * The difference between the byte/transaction count recorded in * the transaction and the count last time we recorded a completion * tells us exactly how much data has been transferred between * completions. * * Calling this each time we learn of a newly-completed transaction * allows us to provide accurate information to the network stack * about how much work has been completed by the hardware at a given * point in time. */ static void gsi_channel_tx_update(struct gsi_channel *channel, struct gsi_trans *trans) { u64 byte_count = trans->byte_count + trans->len; u64 trans_count = trans->trans_count + 1; byte_count -= channel->compl_byte_count; channel->compl_byte_count += byte_count; trans_count -= channel->compl_trans_count; channel->compl_trans_count += trans_count; ipa_gsi_channel_tx_completed(channel->gsi, gsi_channel_id(channel), trans_count, byte_count); } /* Channel control interrupt handler */ static void gsi_isr_chan_ctrl(struct gsi *gsi) { u32 channel_mask; channel_mask = ioread32(gsi->virt + GSI_CNTXT_SRC_CH_IRQ_OFFSET); iowrite32(channel_mask, gsi->virt + GSI_CNTXT_SRC_CH_IRQ_CLR_OFFSET); while (channel_mask) { u32 channel_id = __ffs(channel_mask); struct gsi_channel *channel; channel_mask ^= BIT(channel_id); channel = &gsi->channel[channel_id]; complete(&channel->completion); } } /* Event ring control interrupt handler */ static void gsi_isr_evt_ctrl(struct gsi *gsi) { u32 event_mask; event_mask = ioread32(gsi->virt + GSI_CNTXT_SRC_EV_CH_IRQ_OFFSET); iowrite32(event_mask, gsi->virt + GSI_CNTXT_SRC_EV_CH_IRQ_CLR_OFFSET); while (event_mask) { u32 evt_ring_id = __ffs(event_mask); struct gsi_evt_ring *evt_ring; event_mask ^= BIT(evt_ring_id); evt_ring = &gsi->evt_ring[evt_ring_id]; evt_ring->state = gsi_evt_ring_state(gsi, evt_ring_id); complete(&evt_ring->completion); } } /* Global channel error interrupt handler */ static void gsi_isr_glob_chan_err(struct gsi *gsi, u32 err_ee, u32 channel_id, u32 code) { if (code == GSI_OUT_OF_RESOURCES_ERR) { dev_err(gsi->dev, "channel %u out of resources\n", channel_id); complete(&gsi->channel[channel_id].completion); return; } /* Report, but otherwise ignore all other error codes */ dev_err(gsi->dev, "channel %u global error ee 0x%08x code 0x%08x\n", channel_id, err_ee, code); } /* Global event error interrupt handler */ static void gsi_isr_glob_evt_err(struct gsi *gsi, u32 err_ee, u32 evt_ring_id, u32 code) { if (code == GSI_OUT_OF_RESOURCES_ERR) { struct gsi_evt_ring *evt_ring = &gsi->evt_ring[evt_ring_id]; u32 channel_id = gsi_channel_id(evt_ring->channel); complete(&evt_ring->completion); dev_err(gsi->dev, "evt_ring for channel %u out of resources\n", channel_id); return; } /* Report, but otherwise ignore all other error codes */ dev_err(gsi->dev, "event ring %u global error ee %u code 0x%08x\n", evt_ring_id, err_ee, code); } /* Global error interrupt handler */ static void gsi_isr_glob_err(struct gsi *gsi) { enum gsi_err_type type; enum gsi_err_code code; u32 which; u32 val; u32 ee; /* Get the logged error, then reinitialize the log */ val = ioread32(gsi->virt + GSI_ERROR_LOG_OFFSET); iowrite32(0, gsi->virt + GSI_ERROR_LOG_OFFSET); iowrite32(~0, gsi->virt + GSI_ERROR_LOG_CLR_OFFSET); ee = u32_get_bits(val, ERR_EE_FMASK); which = u32_get_bits(val, ERR_VIRT_IDX_FMASK); type = u32_get_bits(val, ERR_TYPE_FMASK); code = u32_get_bits(val, ERR_CODE_FMASK); if (type == GSI_ERR_TYPE_CHAN) gsi_isr_glob_chan_err(gsi, ee, which, code); else if (type == GSI_ERR_TYPE_EVT) gsi_isr_glob_evt_err(gsi, ee, which, code); else /* type GSI_ERR_TYPE_GLOB should be fatal */ dev_err(gsi->dev, "unexpected global error 0x%08x\n", type); } /* Generic EE interrupt handler */ static void gsi_isr_gp_int1(struct gsi *gsi) { u32 result; u32 val; val = ioread32(gsi->virt + GSI_CNTXT_SCRATCH_0_OFFSET); result = u32_get_bits(val, GENERIC_EE_RESULT_FMASK); if (result != GENERIC_EE_SUCCESS_FVAL) dev_err(gsi->dev, "global INT1 generic result %u\n", result); complete(&gsi->completion); } /* Inter-EE interrupt handler */ static void gsi_isr_glob_ee(struct gsi *gsi) { u32 val; val = ioread32(gsi->virt + GSI_CNTXT_GLOB_IRQ_STTS_OFFSET); if (val & ERROR_INT_FMASK) gsi_isr_glob_err(gsi); iowrite32(val, gsi->virt + GSI_CNTXT_GLOB_IRQ_CLR_OFFSET); val &= ~ERROR_INT_FMASK; if (val & EN_GP_INT1_FMASK) { val ^= EN_GP_INT1_FMASK; gsi_isr_gp_int1(gsi); } if (val) dev_err(gsi->dev, "unexpected global interrupt 0x%08x\n", val); } /* I/O completion interrupt event */ static void gsi_isr_ieob(struct gsi *gsi) { u32 event_mask; event_mask = ioread32(gsi->virt + GSI_CNTXT_SRC_IEOB_IRQ_OFFSET); iowrite32(event_mask, gsi->virt + GSI_CNTXT_SRC_IEOB_IRQ_CLR_OFFSET); while (event_mask) { u32 evt_ring_id = __ffs(event_mask); event_mask ^= BIT(evt_ring_id); gsi_irq_ieob_disable(gsi, evt_ring_id); napi_schedule(&gsi->evt_ring[evt_ring_id].channel->napi); } } /* General event interrupts represent serious problems, so report them */ static void gsi_isr_general(struct gsi *gsi) { struct device *dev = gsi->dev; u32 val; val = ioread32(gsi->virt + GSI_CNTXT_GSI_IRQ_STTS_OFFSET); iowrite32(val, gsi->virt + GSI_CNTXT_GSI_IRQ_CLR_OFFSET); if (val) dev_err(dev, "unexpected general interrupt 0x%08x\n", val); } /** * gsi_isr() - Top level GSI interrupt service routine * @irq: Interrupt number (ignored) * @dev_id: GSI pointer supplied to request_irq() * * This is the main handler function registered for the GSI IRQ. Each type * of interrupt has a separate handler function that is called from here. */ static irqreturn_t gsi_isr(int irq, void *dev_id) { struct gsi *gsi = dev_id; u32 intr_mask; u32 cnt = 0; while ((intr_mask = ioread32(gsi->virt + GSI_CNTXT_TYPE_IRQ_OFFSET))) { /* intr_mask contains bitmask of pending GSI interrupts */ do { u32 gsi_intr = BIT(__ffs(intr_mask)); intr_mask ^= gsi_intr; switch (gsi_intr) { case CH_CTRL_FMASK: gsi_isr_chan_ctrl(gsi); break; case EV_CTRL_FMASK: gsi_isr_evt_ctrl(gsi); break; case GLOB_EE_FMASK: gsi_isr_glob_ee(gsi); break; case IEOB_FMASK: gsi_isr_ieob(gsi); break; case GENERAL_FMASK: gsi_isr_general(gsi); break; default: dev_err(gsi->dev, "unrecognized interrupt type 0x%08x\n", gsi_intr); break; } } while (intr_mask); if (++cnt > GSI_ISR_MAX_ITER) { dev_err(gsi->dev, "interrupt flood\n"); break; } } return IRQ_HANDLED; } /* Return the transaction associated with a transfer completion event */ static struct gsi_trans *gsi_event_trans(struct gsi_channel *channel, struct gsi_event *event) { u32 tre_offset; u32 tre_index; /* Event xfer_ptr records the TRE it's associated with */ tre_offset = le64_to_cpu(event->xfer_ptr) & GENMASK(31, 0); tre_index = gsi_ring_index(&channel->tre_ring, tre_offset); return gsi_channel_trans_mapped(channel, tre_index); } /** * gsi_evt_ring_rx_update() - Record lengths of received data * @evt_ring: Event ring associated with channel that received packets * @index: Event index in ring reported by hardware * * Events for RX channels contain the actual number of bytes received into * the buffer. Every event has a transaction associated with it, and here * we update transactions to record their actual received lengths. * * This function is called whenever we learn that the GSI hardware has filled * new events since the last time we checked. The ring's index field tells * the first entry in need of processing. The index provided is the * first *unfilled* event in the ring (following the last filled one). * * Events are sequential within the event ring, and transactions are * sequential within the transaction pool. * * Note that @index always refers to an element *within* the event ring. */ static void gsi_evt_ring_rx_update(struct gsi_evt_ring *evt_ring, u32 index) { struct gsi_channel *channel = evt_ring->channel; struct gsi_ring *ring = &evt_ring->ring; struct gsi_trans_info *trans_info; struct gsi_event *event_done; struct gsi_event *event; struct gsi_trans *trans; u32 byte_count = 0; u32 old_index; u32 event_avail; trans_info = &channel->trans_info; /* We'll start with the oldest un-processed event. RX channels * replenish receive buffers in single-TRE transactions, so we * can just map that event to its transaction. Transactions * associated with completion events are consecutive. */ old_index = ring->index; event = gsi_ring_virt(ring, old_index); trans = gsi_event_trans(channel, event); /* Compute the number of events to process before we wrap, * and determine when we'll be done processing events. */ event_avail = ring->count - old_index % ring->count; event_done = gsi_ring_virt(ring, index); do { trans->len = __le16_to_cpu(event->len); byte_count += trans->len; /* Move on to the next event and transaction */ if (--event_avail) event++; else event = gsi_ring_virt(ring, 0); trans = gsi_trans_pool_next(&trans_info->pool, trans); } while (event != event_done); /* We record RX bytes when they are received */ channel->byte_count += byte_count; channel->trans_count++; } /* Initialize a ring, including allocating DMA memory for its entries */ static int gsi_ring_alloc(struct gsi *gsi, struct gsi_ring *ring, u32 count) { size_t size = count * GSI_RING_ELEMENT_SIZE; struct device *dev = gsi->dev; dma_addr_t addr; /* Hardware requires a 2^n ring size, with alignment equal to size */ ring->virt = dma_alloc_coherent(dev, size, &addr, GFP_KERNEL); if (ring->virt && addr % size) { dma_free_coherent(dev, size, ring->virt, ring->addr); dev_err(dev, "unable to alloc 0x%zx-aligned ring buffer\n", size); return -EINVAL; /* Not a good error value, but distinct */ } else if (!ring->virt) { return -ENOMEM; } ring->addr = addr; ring->count = count; return 0; } /* Free a previously-allocated ring */ static void gsi_ring_free(struct gsi *gsi, struct gsi_ring *ring) { size_t size = ring->count * GSI_RING_ELEMENT_SIZE; dma_free_coherent(gsi->dev, size, ring->virt, ring->addr); } /* Allocate an available event ring id */ static int gsi_evt_ring_id_alloc(struct gsi *gsi) { u32 evt_ring_id; if (gsi->event_bitmap == ~0U) { dev_err(gsi->dev, "event rings exhausted\n"); return -ENOSPC; } evt_ring_id = ffz(gsi->event_bitmap); gsi->event_bitmap |= BIT(evt_ring_id); return (int)evt_ring_id; } /* Free a previously-allocated event ring id */ static void gsi_evt_ring_id_free(struct gsi *gsi, u32 evt_ring_id) { gsi->event_bitmap &= ~BIT(evt_ring_id); } /* Ring a channel doorbell, reporting the first un-filled entry */ void gsi_channel_doorbell(struct gsi_channel *channel) { struct gsi_ring *tre_ring = &channel->tre_ring; u32 channel_id = gsi_channel_id(channel); struct gsi *gsi = channel->gsi; u32 val; /* Note: index *must* be used modulo the ring count here */ val = gsi_ring_addr(tre_ring, tre_ring->index % tre_ring->count); iowrite32(val, gsi->virt + GSI_CH_C_DOORBELL_0_OFFSET(channel_id)); } /* Consult hardware, move any newly completed transactions to completed list */ static void gsi_channel_update(struct gsi_channel *channel) { u32 evt_ring_id = channel->evt_ring_id; struct gsi *gsi = channel->gsi; struct gsi_evt_ring *evt_ring; struct gsi_trans *trans; struct gsi_ring *ring; u32 offset; u32 index; evt_ring = &gsi->evt_ring[evt_ring_id]; ring = &evt_ring->ring; /* See if there's anything new to process; if not, we're done. Note * that index always refers to an entry *within* the event ring. */ offset = GSI_EV_CH_E_CNTXT_4_OFFSET(evt_ring_id); index = gsi_ring_index(ring, ioread32(gsi->virt + offset)); if (index == ring->index % ring->count) return; /* Get the transaction for the latest completed event. Take a * reference to keep it from completing before we give the events * for this and previous transactions back to the hardware. */ trans = gsi_event_trans(channel, gsi_ring_virt(ring, index - 1)); refcount_inc(&trans->refcount); /* For RX channels, update each completed transaction with the number * of bytes that were actually received. For TX channels, report * the number of transactions and bytes this completion represents * up the network stack. */ if (channel->toward_ipa) gsi_channel_tx_update(channel, trans); else gsi_evt_ring_rx_update(evt_ring, index); gsi_trans_move_complete(trans); /* Tell the hardware we've handled these events */ gsi_evt_ring_doorbell(channel->gsi, channel->evt_ring_id, index); gsi_trans_free(trans); } /** * gsi_channel_poll_one() - Return a single completed transaction on a channel * @channel: Channel to be polled * * Return: Transaction pointer, or null if none are available * * This function returns the first entry on a channel's completed transaction * list. If that list is empty, the hardware is consulted to determine * whether any new transactions have completed. If so, they're moved to the * completed list and the new first entry is returned. If there are no more * completed transactions, a null pointer is returned. */ static struct gsi_trans *gsi_channel_poll_one(struct gsi_channel *channel) { struct gsi_trans *trans; /* Get the first transaction from the completed list */ trans = gsi_channel_trans_complete(channel); if (!trans) { /* List is empty; see if there's more to do */ gsi_channel_update(channel); trans = gsi_channel_trans_complete(channel); } if (trans) gsi_trans_move_polled(trans); return trans; } /** * gsi_channel_poll() - NAPI poll function for a channel * @napi: NAPI structure for the channel * @budget: Budget supplied by NAPI core * * Return: Number of items polled (<= budget) * * Single transactions completed by hardware are polled until either * the budget is exhausted, or there are no more. Each transaction * polled is passed to gsi_trans_complete(), to perform remaining * completion processing and retire/free the transaction. */ static int gsi_channel_poll(struct napi_struct *napi, int budget) { struct gsi_channel *channel; int count = 0; channel = container_of(napi, struct gsi_channel, napi); while (count < budget) { struct gsi_trans *trans; count++; trans = gsi_channel_poll_one(channel); if (!trans) break; gsi_trans_complete(trans); } if (count < budget) { napi_complete(&channel->napi); gsi_irq_ieob_enable(channel->gsi, channel->evt_ring_id); } return count; } /* The event bitmap represents which event ids are available for allocation. * Set bits are not available, clear bits can be used. This function * initializes the map so all events supported by the hardware are available, * then precludes any reserved events from being allocated. */ static u32 gsi_event_bitmap_init(u32 evt_ring_max) { u32 event_bitmap = GENMASK(BITS_PER_LONG - 1, evt_ring_max); event_bitmap |= GENMASK(GSI_MHI_EVENT_ID_END, GSI_MHI_EVENT_ID_START); return event_bitmap; } /* Setup function for event rings */ static void gsi_evt_ring_setup(struct gsi *gsi) { /* Nothing to do */ } /* Inverse of gsi_evt_ring_setup() */ static void gsi_evt_ring_teardown(struct gsi *gsi) { /* Nothing to do */ } /* Setup function for a single channel */ static int gsi_channel_setup_one(struct gsi *gsi, u32 channel_id, bool legacy) { struct gsi_channel *channel = &gsi->channel[channel_id]; u32 evt_ring_id = channel->evt_ring_id; int ret; if (!channel->gsi) return 0; /* Ignore uninitialized channels */ ret = gsi_evt_ring_alloc_command(gsi, evt_ring_id); if (ret) return ret; gsi_evt_ring_program(gsi, evt_ring_id); ret = gsi_channel_alloc_command(gsi, channel_id); if (ret) goto err_evt_ring_de_alloc; gsi_channel_program(channel, legacy); if (channel->toward_ipa) netif_tx_napi_add(&gsi->dummy_dev, &channel->napi, gsi_channel_poll, NAPI_POLL_WEIGHT); else netif_napi_add(&gsi->dummy_dev, &channel->napi, gsi_channel_poll, NAPI_POLL_WEIGHT); return 0; err_evt_ring_de_alloc: /* We've done nothing with the event ring yet so don't reset */ gsi_evt_ring_de_alloc_command(gsi, evt_ring_id); return ret; } /* Inverse of gsi_channel_setup_one() */ static void gsi_channel_teardown_one(struct gsi *gsi, u32 channel_id) { struct gsi_channel *channel = &gsi->channel[channel_id]; u32 evt_ring_id = channel->evt_ring_id; if (!channel->gsi) return; /* Ignore uninitialized channels */ netif_napi_del(&channel->napi); gsi_channel_deprogram(channel); gsi_channel_de_alloc_command(gsi, channel_id); gsi_evt_ring_reset_command(gsi, evt_ring_id); gsi_evt_ring_de_alloc_command(gsi, evt_ring_id); } static int gsi_generic_command(struct gsi *gsi, u32 channel_id, enum gsi_generic_cmd_opcode opcode) { struct completion *completion = &gsi->completion; u32 val; /* First zero the result code field */ val = ioread32(gsi->virt + GSI_CNTXT_SCRATCH_0_OFFSET); val &= ~GENERIC_EE_RESULT_FMASK; iowrite32(val, gsi->virt + GSI_CNTXT_SCRATCH_0_OFFSET); /* Now issue the command */ val = u32_encode_bits(opcode, GENERIC_OPCODE_FMASK); val |= u32_encode_bits(channel_id, GENERIC_CHID_FMASK); val |= u32_encode_bits(GSI_EE_MODEM, GENERIC_EE_FMASK); if (gsi_command(gsi, GSI_GENERIC_CMD_OFFSET, val, completion)) return 0; /* Success! */ dev_err(gsi->dev, "GSI generic command %u to channel %u timed out\n", opcode, channel_id); return -ETIMEDOUT; } static int gsi_modem_channel_alloc(struct gsi *gsi, u32 channel_id) { return gsi_generic_command(gsi, channel_id, GSI_GENERIC_ALLOCATE_CHANNEL); } static void gsi_modem_channel_halt(struct gsi *gsi, u32 channel_id) { int ret; ret = gsi_generic_command(gsi, channel_id, GSI_GENERIC_HALT_CHANNEL); if (ret) dev_err(gsi->dev, "error %d halting modem channel %u\n", ret, channel_id); } /* Setup function for channels */ static int gsi_channel_setup(struct gsi *gsi, bool legacy) { u32 channel_id = 0; u32 mask; int ret; gsi_evt_ring_setup(gsi); gsi_irq_enable(gsi); mutex_lock(&gsi->mutex); do { ret = gsi_channel_setup_one(gsi, channel_id, legacy); if (ret) goto err_unwind; } while (++channel_id < gsi->channel_count); /* Make sure no channels were defined that hardware does not support */ while (channel_id < GSI_CHANNEL_COUNT_MAX) { struct gsi_channel *channel = &gsi->channel[channel_id++]; if (!channel->gsi) continue; /* Ignore uninitialized channels */ dev_err(gsi->dev, "channel %u not supported by hardware\n", channel_id - 1); channel_id = gsi->channel_count; goto err_unwind; } /* Allocate modem channels if necessary */ mask = gsi->modem_channel_bitmap; while (mask) { u32 modem_channel_id = __ffs(mask); ret = gsi_modem_channel_alloc(gsi, modem_channel_id); if (ret) goto err_unwind_modem; /* Clear bit from mask only after success (for unwind) */ mask ^= BIT(modem_channel_id); } mutex_unlock(&gsi->mutex); return 0; err_unwind_modem: /* Compute which modem channels need to be deallocated */ mask ^= gsi->modem_channel_bitmap; while (mask) { u32 channel_id = __fls(mask); mask ^= BIT(channel_id); gsi_modem_channel_halt(gsi, channel_id); } err_unwind: while (channel_id--) gsi_channel_teardown_one(gsi, channel_id); mutex_unlock(&gsi->mutex); gsi_irq_disable(gsi); gsi_evt_ring_teardown(gsi); return ret; } /* Inverse of gsi_channel_setup() */ static void gsi_channel_teardown(struct gsi *gsi) { u32 mask = gsi->modem_channel_bitmap; u32 channel_id; mutex_lock(&gsi->mutex); while (mask) { u32 channel_id = __fls(mask); mask ^= BIT(channel_id); gsi_modem_channel_halt(gsi, channel_id); } channel_id = gsi->channel_count - 1; do gsi_channel_teardown_one(gsi, channel_id); while (channel_id--); mutex_unlock(&gsi->mutex); gsi_irq_disable(gsi); gsi_evt_ring_teardown(gsi); } /* Setup function for GSI. GSI firmware must be loaded and initialized */ int gsi_setup(struct gsi *gsi, bool legacy) { struct device *dev = gsi->dev; u32 val; /* Here is where we first touch the GSI hardware */ val = ioread32(gsi->virt + GSI_GSI_STATUS_OFFSET); if (!(val & ENABLED_FMASK)) { dev_err(dev, "GSI has not been enabled\n"); return -EIO; } val = ioread32(gsi->virt + GSI_GSI_HW_PARAM_2_OFFSET); gsi->channel_count = u32_get_bits(val, NUM_CH_PER_EE_FMASK); if (!gsi->channel_count) { dev_err(dev, "GSI reports zero channels supported\n"); return -EINVAL; } if (gsi->channel_count > GSI_CHANNEL_COUNT_MAX) { dev_warn(dev, "limiting to %u channels; hardware supports %u\n", GSI_CHANNEL_COUNT_MAX, gsi->channel_count); gsi->channel_count = GSI_CHANNEL_COUNT_MAX; } gsi->evt_ring_count = u32_get_bits(val, NUM_EV_PER_EE_FMASK); if (!gsi->evt_ring_count) { dev_err(dev, "GSI reports zero event rings supported\n"); return -EINVAL; } if (gsi->evt_ring_count > GSI_EVT_RING_COUNT_MAX) { dev_warn(dev, "limiting to %u event rings; hardware supports %u\n", GSI_EVT_RING_COUNT_MAX, gsi->evt_ring_count); gsi->evt_ring_count = GSI_EVT_RING_COUNT_MAX; } /* Initialize the error log */ iowrite32(0, gsi->virt + GSI_ERROR_LOG_OFFSET); /* Writing 1 indicates IRQ interrupts; 0 would be MSI */ iowrite32(1, gsi->virt + GSI_CNTXT_INTSET_OFFSET); return gsi_channel_setup(gsi, legacy); } /* Inverse of gsi_setup() */ void gsi_teardown(struct gsi *gsi) { gsi_channel_teardown(gsi); } /* Initialize a channel's event ring */ static int gsi_channel_evt_ring_init(struct gsi_channel *channel) { struct gsi *gsi = channel->gsi; struct gsi_evt_ring *evt_ring; int ret; ret = gsi_evt_ring_id_alloc(gsi); if (ret < 0) return ret; channel->evt_ring_id = ret; evt_ring = &gsi->evt_ring[channel->evt_ring_id]; evt_ring->channel = channel; ret = gsi_ring_alloc(gsi, &evt_ring->ring, channel->event_count); if (!ret) return 0; /* Success! */ dev_err(gsi->dev, "error %d allocating channel %u event ring\n", ret, gsi_channel_id(channel)); gsi_evt_ring_id_free(gsi, channel->evt_ring_id); return ret; } /* Inverse of gsi_channel_evt_ring_init() */ static void gsi_channel_evt_ring_exit(struct gsi_channel *channel) { u32 evt_ring_id = channel->evt_ring_id; struct gsi *gsi = channel->gsi; struct gsi_evt_ring *evt_ring; evt_ring = &gsi->evt_ring[evt_ring_id]; gsi_ring_free(gsi, &evt_ring->ring); gsi_evt_ring_id_free(gsi, evt_ring_id); } /* Init function for event rings */ static void gsi_evt_ring_init(struct gsi *gsi) { u32 evt_ring_id = 0; gsi->event_bitmap = gsi_event_bitmap_init(GSI_EVT_RING_COUNT_MAX); gsi->event_enable_bitmap = 0; do init_completion(&gsi->evt_ring[evt_ring_id].completion); while (++evt_ring_id < GSI_EVT_RING_COUNT_MAX); } /* Inverse of gsi_evt_ring_init() */ static void gsi_evt_ring_exit(struct gsi *gsi) { /* Nothing to do */ } static bool gsi_channel_data_valid(struct gsi *gsi, const struct ipa_gsi_endpoint_data *data) { #ifdef IPA_VALIDATION u32 channel_id = data->channel_id; struct device *dev = gsi->dev; /* Make sure channel ids are in the range driver supports */ if (channel_id >= GSI_CHANNEL_COUNT_MAX) { dev_err(dev, "bad channel id %u; must be less than %u\n", channel_id, GSI_CHANNEL_COUNT_MAX); return false; } if (data->ee_id != GSI_EE_AP && data->ee_id != GSI_EE_MODEM) { dev_err(dev, "bad EE id %u; not AP or modem\n", data->ee_id); return false; } if (!data->channel.tlv_count || data->channel.tlv_count > GSI_TLV_MAX) { dev_err(dev, "channel %u bad tlv_count %u; must be 1..%u\n", channel_id, data->channel.tlv_count, GSI_TLV_MAX); return false; } /* We have to allow at least one maximally-sized transaction to * be outstanding (which would use tlv_count TREs). Given how * gsi_channel_tre_max() is computed, tre_count has to be almost * twice the TLV FIFO size to satisfy this requirement. */ if (data->channel.tre_count < 2 * data->channel.tlv_count - 1) { dev_err(dev, "channel %u TLV count %u exceeds TRE count %u\n", channel_id, data->channel.tlv_count, data->channel.tre_count); return false; } if (!is_power_of_2(data->channel.tre_count)) { dev_err(dev, "channel %u bad tre_count %u; not power of 2\n", channel_id, data->channel.tre_count); return false; } if (!is_power_of_2(data->channel.event_count)) { dev_err(dev, "channel %u bad event_count %u; not power of 2\n", channel_id, data->channel.event_count); return false; } #endif /* IPA_VALIDATION */ return true; } /* Init function for a single channel */ static int gsi_channel_init_one(struct gsi *gsi, const struct ipa_gsi_endpoint_data *data, bool command, bool prefetch) { struct gsi_channel *channel; u32 tre_count; int ret; if (!gsi_channel_data_valid(gsi, data)) return -EINVAL; /* Worst case we need an event for every outstanding TRE */ if (data->channel.tre_count > data->channel.event_count) { tre_count = data->channel.event_count; dev_warn(gsi->dev, "channel %u limited to %u TREs\n", data->channel_id, tre_count); } else { tre_count = data->channel.tre_count; } channel = &gsi->channel[data->channel_id]; memset(channel, 0, sizeof(*channel)); channel->gsi = gsi; channel->toward_ipa = data->toward_ipa; channel->command = command; channel->use_prefetch = command && prefetch; channel->tlv_count = data->channel.tlv_count; channel->tre_count = tre_count; channel->event_count = data->channel.event_count; init_completion(&channel->completion); ret = gsi_channel_evt_ring_init(channel); if (ret) goto err_clear_gsi; ret = gsi_ring_alloc(gsi, &channel->tre_ring, data->channel.tre_count); if (ret) { dev_err(gsi->dev, "error %d allocating channel %u ring\n", ret, data->channel_id); goto err_channel_evt_ring_exit; } ret = gsi_channel_trans_init(gsi, data->channel_id); if (ret) goto err_ring_free; if (command) { u32 tre_max = gsi_channel_tre_max(gsi, data->channel_id); ret = ipa_cmd_pool_init(channel, tre_max); } if (!ret) return 0; /* Success! */ gsi_channel_trans_exit(channel); err_ring_free: gsi_ring_free(gsi, &channel->tre_ring); err_channel_evt_ring_exit: gsi_channel_evt_ring_exit(channel); err_clear_gsi: channel->gsi = NULL; /* Mark it not (fully) initialized */ return ret; } /* Inverse of gsi_channel_init_one() */ static void gsi_channel_exit_one(struct gsi_channel *channel) { if (!channel->gsi) return; /* Ignore uninitialized channels */ if (channel->command) ipa_cmd_pool_exit(channel); gsi_channel_trans_exit(channel); gsi_ring_free(channel->gsi, &channel->tre_ring); gsi_channel_evt_ring_exit(channel); } /* Init function for channels */ static int gsi_channel_init(struct gsi *gsi, bool prefetch, u32 count, const struct ipa_gsi_endpoint_data *data, bool modem_alloc) { int ret = 0; u32 i; gsi_evt_ring_init(gsi); /* The endpoint data array is indexed by endpoint name */ for (i = 0; i < count; i++) { bool command = i == IPA_ENDPOINT_AP_COMMAND_TX; if (ipa_gsi_endpoint_data_empty(&data[i])) continue; /* Skip over empty slots */ /* Mark modem channels to be allocated (hardware workaround) */ if (data[i].ee_id == GSI_EE_MODEM) { if (modem_alloc) gsi->modem_channel_bitmap |= BIT(data[i].channel_id); continue; } ret = gsi_channel_init_one(gsi, &data[i], command, prefetch); if (ret) goto err_unwind; } return ret; err_unwind: while (i--) { if (ipa_gsi_endpoint_data_empty(&data[i])) continue; if (modem_alloc && data[i].ee_id == GSI_EE_MODEM) { gsi->modem_channel_bitmap &= ~BIT(data[i].channel_id); continue; } gsi_channel_exit_one(&gsi->channel[data->channel_id]); } gsi_evt_ring_exit(gsi); return ret; } /* Inverse of gsi_channel_init() */ static void gsi_channel_exit(struct gsi *gsi) { u32 channel_id = GSI_CHANNEL_COUNT_MAX - 1; do gsi_channel_exit_one(&gsi->channel[channel_id]); while (channel_id--); gsi->modem_channel_bitmap = 0; gsi_evt_ring_exit(gsi); } /* Init function for GSI. GSI hardware does not need to be "ready" */ int gsi_init(struct gsi *gsi, struct platform_device *pdev, bool prefetch, u32 count, const struct ipa_gsi_endpoint_data *data, bool modem_alloc) { struct device *dev = &pdev->dev; struct resource *res; resource_size_t size; unsigned int irq; int ret; gsi_validate_build(); gsi->dev = dev; /* The GSI layer performs NAPI on all endpoints. NAPI requires a * network device structure, but the GSI layer does not have one, * so we must create a dummy network device for this purpose. */ init_dummy_netdev(&gsi->dummy_dev); /* Get the GSI IRQ and request for it to wake the system */ ret = platform_get_irq_byname(pdev, "gsi"); if (ret <= 0) { dev_err(dev, "DT error %d getting \"gsi\" IRQ property\n", ret); return ret ? : -EINVAL; } irq = ret; ret = request_irq(irq, gsi_isr, 0, "gsi", gsi); if (ret) { dev_err(dev, "error %d requesting \"gsi\" IRQ\n", ret); return ret; } gsi->irq = irq; ret = enable_irq_wake(gsi->irq); if (ret) dev_warn(dev, "error %d enabling gsi wake irq\n", ret); gsi->irq_wake_enabled = !ret; /* Get GSI memory range and map it */ res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "gsi"); if (!res) { dev_err(dev, "DT error getting \"gsi\" memory property\n"); ret = -ENODEV; goto err_disable_irq_wake; } size = resource_size(res); if (res->start > U32_MAX || size > U32_MAX - res->start) { dev_err(dev, "DT memory resource \"gsi\" out of range\n"); ret = -EINVAL; goto err_disable_irq_wake; } gsi->virt = ioremap(res->start, size); if (!gsi->virt) { dev_err(dev, "unable to remap \"gsi\" memory\n"); ret = -ENOMEM; goto err_disable_irq_wake; } ret = gsi_channel_init(gsi, prefetch, count, data, modem_alloc); if (ret) goto err_iounmap; mutex_init(&gsi->mutex); init_completion(&gsi->completion); return 0; err_iounmap: iounmap(gsi->virt); err_disable_irq_wake: if (gsi->irq_wake_enabled) (void)disable_irq_wake(gsi->irq); free_irq(gsi->irq, gsi); return ret; } /* Inverse of gsi_init() */ void gsi_exit(struct gsi *gsi) { mutex_destroy(&gsi->mutex); gsi_channel_exit(gsi); if (gsi->irq_wake_enabled) (void)disable_irq_wake(gsi->irq); free_irq(gsi->irq, gsi); iounmap(gsi->virt); } /* The maximum number of outstanding TREs on a channel. This limits * a channel's maximum number of transactions outstanding (worst case * is one TRE per transaction). * * The absolute limit is the number of TREs in the channel's TRE ring, * and in theory we should be able use all of them. But in practice, * doing that led to the hardware reporting exhaustion of event ring * slots for writing completion information. So the hardware limit * would be (tre_count - 1). * * We reduce it a bit further though. Transaction resource pools are * sized to be a little larger than this maximum, to allow resource * allocations to always be contiguous. The number of entries in a * TRE ring buffer is a power of 2, and the extra resources in a pool * tends to nearly double the memory allocated for it. Reducing the * maximum number of outstanding TREs allows the number of entries in * a pool to avoid crossing that power-of-2 boundary, and this can * substantially reduce pool memory requirements. The number we * reduce it by matches the number added in gsi_trans_pool_init(). */ u32 gsi_channel_tre_max(struct gsi *gsi, u32 channel_id) { struct gsi_channel *channel = &gsi->channel[channel_id]; /* Hardware limit is channel->tre_count - 1 */ return channel->tre_count - (channel->tlv_count - 1); } /* Returns the maximum number of TREs in a single transaction for a channel */ u32 gsi_channel_trans_tre_max(struct gsi *gsi, u32 channel_id) { struct gsi_channel *channel = &gsi->channel[channel_id]; return channel->tlv_count; }
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