| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Iñaky Pérez-González | 2156 | 93.41% | 6 | 28.57% |
| Cindy H. Kao | 78 | 3.38% | 1 | 4.76% |
| Prasanna S. Panchamukhi | 60 | 2.60% | 8 | 38.10% |
| Rusty Russell | 4 | 0.17% | 1 | 4.76% |
| Tejun Heo | 3 | 0.13% | 1 | 4.76% |
| Paul Gortmaker | 3 | 0.13% | 1 | 4.76% |
| Lucas De Marchi | 2 | 0.09% | 1 | 4.76% |
| Frans Pop | 1 | 0.04% | 1 | 4.76% |
| Roel Kluin | 1 | 0.04% | 1 | 4.76% |
| Total | 2308 | 21 |
/* * Intel Wireless WiMAX Connection 2400m * Generic (non-bus specific) TX handling * * * Copyright (C) 2007-2008 Intel Corporation. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * * Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in * the documentation and/or other materials provided with the * distribution. * * Neither the name of Intel Corporation nor the names of its * contributors may be used to endorse or promote products derived * from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. * * * Intel Corporation <linux-wimax@intel.com> * Yanir Lubetkin <yanirx.lubetkin@intel.com> * - Initial implementation * * Intel Corporation <linux-wimax@intel.com> * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com> * - Rewritten to use a single FIFO to lower the memory allocation * pressure and optimize cache hits when copying to the queue, as * well as splitting out bus-specific code. * * * Implements data transmission to the device; this is done through a * software FIFO, as data/control frames can be coalesced (while the * device is reading the previous tx transaction, others accumulate). * * A FIFO is used because at the end it is resource-cheaper that trying * to implement scatter/gather over USB. As well, most traffic is going * to be download (vs upload). * * The format for sending/receiving data to/from the i2400m is * described in detail in rx.c:PROTOCOL FORMAT. In here we implement * the transmission of that. This is split between a bus-independent * part that just prepares everything and a bus-specific part that * does the actual transmission over the bus to the device (in the * bus-specific driver). * * * The general format of a device-host transaction is MSG-HDR, PLD1, * PLD2...PLDN, PL1, PL2,...PLN, PADDING. * * Because we need the send payload descriptors and then payloads and * because it is kind of expensive to do scatterlists in USB (one URB * per node), it becomes cheaper to append all the data to a FIFO * (copying to a FIFO potentially in cache is cheaper). * * Then the bus-specific code takes the parts of that FIFO that are * written and passes them to the device. * * So the concepts to keep in mind there are: * * We use a FIFO to queue the data in a linear buffer. We first append * a MSG-HDR, space for I2400M_TX_PLD_MAX payload descriptors and then * go appending payloads until we run out of space or of payload * descriptors. Then we append padding to make the whole transaction a * multiple of i2400m->bus_tx_block_size (as defined by the bus layer). * * - A TX message: a combination of a message header, payload * descriptors and payloads. * * Open: it is marked as active (i2400m->tx_msg is valid) and we * can keep adding payloads to it. * * Closed: we are not appending more payloads to this TX message * (exahusted space in the queue, too many payloads or * whichever). We have appended padding so the whole message * length is aligned to i2400m->bus_tx_block_size (as set by the * bus/transport layer). * * - Most of the time we keep a TX message open to which we append * payloads. * * - If we are going to append and there is no more space (we are at * the end of the FIFO), we close the message, mark the rest of the * FIFO space unusable (skip_tail), create a new message at the * beginning of the FIFO (if there is space) and append the message * there. * * This is because we need to give linear TX messages to the bus * engine. So we don't write a message to the remaining FIFO space * until the tail and continue at the head of it. * * - We overload one of the fields in the message header to use it as * 'size' of the TX message, so we can iterate over them. It also * contains a flag that indicates if we have to skip it or not. * When we send the buffer, we update that to its real on-the-wire * value. * * - The MSG-HDR PLD1...PLD2 stuff has to be a size multiple of 16. * * It follows that if MSG-HDR says we have N messages, the whole * header + descriptors is 16 + 4*N; for those to be a multiple of * 16, it follows that N can be 4, 8, 12, ... (32, 48, 64, 80... * bytes). * * So if we have only 1 payload, we have to submit a header that in * all truth has space for 4. * * The implication is that we reserve space for 12 (64 bytes); but * if we fill up only (eg) 2, our header becomes 32 bytes only. So * the TX engine has to shift those 32 bytes of msg header and 2 * payloads and padding so that right after it the payloads start * and the TX engine has to know about that. * * It is cheaper to move the header up than the whole payloads down. * * We do this in i2400m_tx_close(). See 'i2400m_msg_hdr->offset'. * * - Each payload has to be size-padded to 16 bytes; before appending * it, we just do it. * * - The whole message has to be padded to i2400m->bus_tx_block_size; * we do this at close time. Thus, when reserving space for the * payload, we always make sure there is also free space for this * padding that sooner or later will happen. * * When we append a message, we tell the bus specific code to kick in * TXs. It will TX (in parallel) until the buffer is exhausted--hence * the lockin we do. The TX code will only send a TX message at the * time (which remember, might contain more than one payload). Of * course, when the bus-specific driver attempts to TX a message that * is still open, it gets closed first. * * Gee, this is messy; well a picture. In the example below we have a * partially full FIFO, with a closed message ready to be delivered * (with a moved message header to make sure it is size-aligned to * 16), TAIL room that was unusable (and thus is marked with a message * header that says 'skip this') and at the head of the buffer, an * incomplete message with a couple of payloads. * * N ___________________________________________________ * | | * | TAIL room | * | | * | msg_hdr to skip (size |= 0x80000) | * |---------------------------------------------------|------- * | | /|\ * | | | * | TX message padding | | * | | | * | | | * |- - - - - - - - - - - - - - - - - - - - - - - - - -| | * | | | * | payload 1 | | * | | N * tx_block_size * | | | * |- - - - - - - - - - - - - - - - - - - - - - - - - -| | * | | | * | payload 1 | | * | | | * | | | * |- - - - - - - - - - - - - - - - - - - - - - - - - -|- -|- - - - * | padding 3 /|\ | | /|\ * | padding 2 | | | | * | pld 1 32 bytes (2 * 16) | | | * | pld 0 | | | | * | moved msg_hdr \|/ | \|/ | * |- - - - - - - - - - - - - - - - - - - - - - - - - -|- - - | * | | _PLD_SIZE * | unused | | * | | | * |- - - - - - - - - - - - - - - - - - - - - - - - - -| | * | msg_hdr (size X) [this message is closed] | \|/ * |===================================================|========== <=== OUT * | | * | | * | | * | Free rooom | * | | * | | * | | * | | * | | * | | * | | * | | * | | * |===================================================|========== <=== IN * | | * | | * | | * | | * | payload 1 | * | | * | | * |- - - - - - - - - - - - - - - - - - - - - - - - - -| * | | * | payload 0 | * | | * | | * |- - - - - - - - - - - - - - - - - - - - - - - - - -| * | pld 11 /|\ | * | ... | | * | pld 1 64 bytes (2 * 16) | * | pld 0 | | * | msg_hdr (size X) \|/ [message is open] | * 0 --------------------------------------------------- * * * ROADMAP * * i2400m_tx_setup() Called by i2400m_setup * i2400m_tx_release() Called by i2400m_release() * * i2400m_tx() Called to send data or control frames * i2400m_tx_fifo_push() Allocates append-space in the FIFO * i2400m_tx_new() Opens a new message in the FIFO * i2400m_tx_fits() Checks if a new payload fits in the message * i2400m_tx_close() Closes an open message in the FIFO * i2400m_tx_skip_tail() Marks unusable FIFO tail space * i2400m->bus_tx_kick() * * Now i2400m->bus_tx_kick() is the the bus-specific driver backend * implementation; that would do: * * i2400m->bus_tx_kick() * i2400m_tx_msg_get() Gets first message ready to go * ...sends it... * i2400m_tx_msg_sent() Ack the message is sent; repeat from * _tx_msg_get() until it returns NULL * (FIFO empty). */ #include <linux/netdevice.h> #include <linux/slab.h> #include <linux/export.h> #include "i2400m.h" #define D_SUBMODULE tx #include "debug-levels.h" enum { /** * TX Buffer size * * Doc says maximum transaction is 16KiB. If we had 16KiB en * route and 16KiB being queued, it boils down to needing * 32KiB. * 32KiB is insufficient for 1400 MTU, hence increasing * tx buffer size to 64KiB. */ I2400M_TX_BUF_SIZE = 65536, /** * Message header and payload descriptors have to be 16 * aligned (16 + 4 * N = 16 * M). If we take that average sent * packets are MTU size (~1400-~1500) it follows that we could * fit at most 10-11 payloads in one transaction. To meet the * alignment requirement, that means we need to leave space * for 12 (64 bytes). To simplify, we leave space for that. If * at the end there are less, we pad up to the nearest * multiple of 16. */ /* * According to Intel Wimax i3200, i5x50 and i6x50 specification * documents, the maximum number of payloads per message can be * up to 60. Increasing the number of payloads to 60 per message * helps to accommodate smaller payloads in a single transaction. */ I2400M_TX_PLD_MAX = 60, I2400M_TX_PLD_SIZE = sizeof(struct i2400m_msg_hdr) + I2400M_TX_PLD_MAX * sizeof(struct i2400m_pld), I2400M_TX_SKIP = 0x80000000, /* * According to Intel Wimax i3200, i5x50 and i6x50 specification * documents, the maximum size of each message can be up to 16KiB. */ I2400M_TX_MSG_SIZE = 16384, }; #define TAIL_FULL ((void *)~(unsigned long)NULL) /* * Calculate how much tail room is available * * Note the trick here. This path is ONLY caleed for Case A (see * i2400m_tx_fifo_push() below), where we have: * * Case A * N ___________ * | tail room | * | | * |<- IN ->| * | | * | data | * | | * |<- OUT ->| * | | * | head room | * 0 ----------- * * When calculating the tail_room, tx_in might get to be zero if * i2400m->tx_in is right at the end of the buffer (really full * buffer) if there is no head room. In this case, tail_room would be * I2400M_TX_BUF_SIZE, although it is actually zero. Hence the final * mod (%) operation. However, when doing this kind of optimization, * i2400m->tx_in being zero would fail, so we treat is an a special * case. */ static inline size_t __i2400m_tx_tail_room(struct i2400m *i2400m) { size_t tail_room; size_t tx_in; if (unlikely(i2400m->tx_in == 0)) return I2400M_TX_BUF_SIZE; tx_in = i2400m->tx_in % I2400M_TX_BUF_SIZE; tail_room = I2400M_TX_BUF_SIZE - tx_in; tail_room %= I2400M_TX_BUF_SIZE; return tail_room; } /* * Allocate @size bytes in the TX fifo, return a pointer to it * * @i2400m: device descriptor * @size: size of the buffer we need to allocate * @padding: ensure that there is at least this many bytes of free * contiguous space in the fifo. This is needed because later on * we might need to add padding. * @try_head: specify either to allocate head room or tail room space * in the TX FIFO. This boolean is required to avoids a system hang * due to an infinite loop caused by i2400m_tx_fifo_push(). * The caller must always try to allocate tail room space first by * calling this routine with try_head = 0. In case if there * is not enough tail room space but there is enough head room space, * (i2400m_tx_fifo_push() returns TAIL_FULL) try to allocate head * room space, by calling this routine again with try_head = 1. * * Returns: * * Pointer to the allocated space. NULL if there is no * space. TAIL_FULL if there is no space at the tail but there is at * the head (Case B below). * * These are the two basic cases we need to keep an eye for -- it is * much better explained in linux/kernel/kfifo.c, but this code * basically does the same. No rocket science here. * * Case A Case B * N ___________ ___________ * | tail room | | data | * | | | | * |<- IN ->| |<- OUT ->| * | | | | * | data | | room | * | | | | * |<- OUT ->| |<- IN ->| * | | | | * | head room | | data | * 0 ----------- ----------- * * We allocate only *contiguous* space. * * We can allocate only from 'room'. In Case B, it is simple; in case * A, we only try from the tail room; if it is not enough, we just * fail and return TAIL_FULL and let the caller figure out if we wants to * skip the tail room and try to allocate from the head. * * There is a corner case, wherein i2400m_tx_new() can get into * an infinite loop calling i2400m_tx_fifo_push(). * In certain situations, tx_in would have reached on the top of TX FIFO * and i2400m_tx_tail_room() returns 0, as described below: * * N ___________ tail room is zero * |<- IN ->| * | | * | | * | | * | data | * |<- OUT ->| * | | * | | * | head room | * 0 ----------- * During such a time, where tail room is zero in the TX FIFO and if there * is a request to add a payload to TX FIFO, which calls: * i2400m_tx() * ->calls i2400m_tx_close() * ->calls i2400m_tx_skip_tail() * goto try_new; * ->calls i2400m_tx_new() * |----> [try_head:] * infinite loop | ->calls i2400m_tx_fifo_push() * | if (tail_room < needed) * | if (head_room => needed) * | return TAIL_FULL; * |<---- goto try_head; * * i2400m_tx() calls i2400m_tx_close() to close the message, since there * is no tail room to accommodate the payload and calls * i2400m_tx_skip_tail() to skip the tail space. Now i2400m_tx() calls * i2400m_tx_new() to allocate space for new message header calling * i2400m_tx_fifo_push() that returns TAIL_FULL, since there is no tail space * to accommodate the message header, but there is enough head space. * The i2400m_tx_new() keeps re-retrying by calling i2400m_tx_fifo_push() * ending up in a loop causing system freeze. * * This corner case is avoided by using a try_head boolean, * as an argument to i2400m_tx_fifo_push(). * * Note: * * Assumes i2400m->tx_lock is taken, and we use that as a barrier * * The indexes keep increasing and we reset them to zero when we * pop data off the queue */ static void *i2400m_tx_fifo_push(struct i2400m *i2400m, size_t size, size_t padding, bool try_head) { struct device *dev = i2400m_dev(i2400m); size_t room, tail_room, needed_size; void *ptr; needed_size = size + padding; room = I2400M_TX_BUF_SIZE - (i2400m->tx_in - i2400m->tx_out); if (room < needed_size) { /* this takes care of Case B */ d_printf(2, dev, "fifo push %zu/%zu: no space\n", size, padding); return NULL; } /* Is there space at the tail? */ tail_room = __i2400m_tx_tail_room(i2400m); if (!try_head && tail_room < needed_size) { /* * If the tail room space is not enough to push the message * in the TX FIFO, then there are two possibilities: * 1. There is enough head room space to accommodate * this message in the TX FIFO. * 2. There is not enough space in the head room and * in tail room of the TX FIFO to accommodate the message. * In the case (1), return TAIL_FULL so that the caller * can figure out, if the caller wants to push the message * into the head room space. * In the case (2), return NULL, indicating that the TX FIFO * cannot accommodate the message. */ if (room - tail_room >= needed_size) { d_printf(2, dev, "fifo push %zu/%zu: tail full\n", size, padding); return TAIL_FULL; /* There might be head space */ } else { d_printf(2, dev, "fifo push %zu/%zu: no head space\n", size, padding); return NULL; /* There is no space */ } } ptr = i2400m->tx_buf + i2400m->tx_in % I2400M_TX_BUF_SIZE; d_printf(2, dev, "fifo push %zu/%zu: at @%zu\n", size, padding, i2400m->tx_in % I2400M_TX_BUF_SIZE); i2400m->tx_in += size; return ptr; } /* * Mark the tail of the FIFO buffer as 'to-skip' * * We should never hit the BUG_ON() because all the sizes we push to * the FIFO are padded to be a multiple of 16 -- the size of *msg * (I2400M_PL_PAD for the payloads, I2400M_TX_PLD_SIZE for the * header). * * Tail room can get to be zero if a message was opened when there was * space only for a header. _tx_close() will mark it as to-skip (as it * will have no payloads) and there will be no more space to flush, so * nothing has to be done here. This is probably cheaper than ensuring * in _tx_new() that there is some space for payloads...as we could * always possibly hit the same problem if the payload wouldn't fit. * * Note: * * Assumes i2400m->tx_lock is taken, and we use that as a barrier * * This path is only taken for Case A FIFO situations [see * i2400m_tx_fifo_push()] */ static void i2400m_tx_skip_tail(struct i2400m *i2400m) { struct device *dev = i2400m_dev(i2400m); size_t tx_in = i2400m->tx_in % I2400M_TX_BUF_SIZE; size_t tail_room = __i2400m_tx_tail_room(i2400m); struct i2400m_msg_hdr *msg = i2400m->tx_buf + tx_in; if (unlikely(tail_room == 0)) return; BUG_ON(tail_room < sizeof(*msg)); msg->size = tail_room | I2400M_TX_SKIP; d_printf(2, dev, "skip tail: skipping %zu bytes @%zu\n", tail_room, tx_in); i2400m->tx_in += tail_room; } /* * Check if a skb will fit in the TX queue's current active TX * message (if there are still descriptors left unused). * * Returns: * 0 if the message won't fit, 1 if it will. * * Note: * * Assumes a TX message is active (i2400m->tx_msg). * * Assumes i2400m->tx_lock is taken, and we use that as a barrier */ static unsigned i2400m_tx_fits(struct i2400m *i2400m) { struct i2400m_msg_hdr *msg_hdr = i2400m->tx_msg; return le16_to_cpu(msg_hdr->num_pls) < I2400M_TX_PLD_MAX; } /* * Start a new TX message header in the queue. * * Reserve memory from the base FIFO engine and then just initialize * the message header. * * We allocate the biggest TX message header we might need (one that'd * fit I2400M_TX_PLD_MAX payloads) -- when it is closed it will be * 'ironed it out' and the unneeded parts removed. * * NOTE: * * Assumes that the previous message is CLOSED (eg: either * there was none or 'i2400m_tx_close()' was called on it). * * Assumes i2400m->tx_lock is taken, and we use that as a barrier */ static void i2400m_tx_new(struct i2400m *i2400m) { struct device *dev = i2400m_dev(i2400m); struct i2400m_msg_hdr *tx_msg; bool try_head = false; BUG_ON(i2400m->tx_msg != NULL); /* * In certain situations, TX queue might have enough space to * accommodate the new message header I2400M_TX_PLD_SIZE, but * might not have enough space to accommodate the payloads. * Adding bus_tx_room_min padding while allocating a new TX message * increases the possibilities of including at least one payload of the * size <= bus_tx_room_min. */ try_head: tx_msg = i2400m_tx_fifo_push(i2400m, I2400M_TX_PLD_SIZE, i2400m->bus_tx_room_min, try_head); if (tx_msg == NULL) goto out; else if (tx_msg == TAIL_FULL) { i2400m_tx_skip_tail(i2400m); d_printf(2, dev, "new TX message: tail full, trying head\n"); try_head = true; goto try_head; } memset(tx_msg, 0, I2400M_TX_PLD_SIZE); tx_msg->size = I2400M_TX_PLD_SIZE; out: i2400m->tx_msg = tx_msg; d_printf(2, dev, "new TX message: %p @%zu\n", tx_msg, (void *) tx_msg - i2400m->tx_buf); } /* * Finalize the current TX message header * * Sets the message header to be at the proper location depending on * how many descriptors we have (check documentation at the file's * header for more info on that). * * Appends padding bytes to make sure the whole TX message (counting * from the 'relocated' message header) is aligned to * tx_block_size. We assume the _append() code has left enough space * in the FIFO for that. If there are no payloads, just pass, as it * won't be transferred. * * The amount of padding bytes depends on how many payloads are in the * TX message, as the "msg header and payload descriptors" will be * shifted up in the buffer. */ static void i2400m_tx_close(struct i2400m *i2400m) { struct device *dev = i2400m_dev(i2400m); struct i2400m_msg_hdr *tx_msg = i2400m->tx_msg; struct i2400m_msg_hdr *tx_msg_moved; size_t aligned_size, padding, hdr_size; void *pad_buf; unsigned num_pls; if (tx_msg->size & I2400M_TX_SKIP) /* a skipper? nothing to do */ goto out; num_pls = le16_to_cpu(tx_msg->num_pls); /* We can get this situation when a new message was started * and there was no space to add payloads before hitting the tail (and taking padding into consideration). */ if (num_pls == 0) { tx_msg->size |= I2400M_TX_SKIP; goto out; } /* Relocate the message header * * Find the current header size, align it to 16 and if we need * to move it so the tail is next to the payloads, move it and * set the offset. * * If it moved, this header is good only for transmission; the * original one (it is kept if we moved) is still used to * figure out where the next TX message starts (and where the * offset to the moved header is). */ hdr_size = sizeof(*tx_msg) + le16_to_cpu(tx_msg->num_pls) * sizeof(tx_msg->pld[0]); hdr_size = ALIGN(hdr_size, I2400M_PL_ALIGN); tx_msg->offset = I2400M_TX_PLD_SIZE - hdr_size; tx_msg_moved = (void *) tx_msg + tx_msg->offset; memmove(tx_msg_moved, tx_msg, hdr_size); tx_msg_moved->size -= tx_msg->offset; /* * Now figure out how much we have to add to the (moved!) * message so the size is a multiple of i2400m->bus_tx_block_size. */ aligned_size = ALIGN(tx_msg_moved->size, i2400m->bus_tx_block_size); padding = aligned_size - tx_msg_moved->size; if (padding > 0) { pad_buf = i2400m_tx_fifo_push(i2400m, padding, 0, 0); if (unlikely(WARN_ON(pad_buf == NULL || pad_buf == TAIL_FULL))) { /* This should not happen -- append should verify * there is always space left at least to append * tx_block_size */ dev_err(dev, "SW BUG! Possible data leakage from memory the " "device should not read for padding - " "size %lu aligned_size %zu tx_buf %p in " "%zu out %zu\n", (unsigned long) tx_msg_moved->size, aligned_size, i2400m->tx_buf, i2400m->tx_in, i2400m->tx_out); } else memset(pad_buf, 0xad, padding); } tx_msg_moved->padding = cpu_to_le16(padding); tx_msg_moved->size += padding; if (tx_msg != tx_msg_moved) tx_msg->size += padding; out: i2400m->tx_msg = NULL; } /** * i2400m_tx - send the data in a buffer to the device * * @buf: pointer to the buffer to transmit * * @buf_len: buffer size * * @pl_type: type of the payload we are sending. * * Returns: * 0 if ok, < 0 errno code on error (-ENOSPC, if there is no more * room for the message in the queue). * * Appends the buffer to the TX FIFO and notifies the bus-specific * part of the driver that there is new data ready to transmit. * Once this function returns, the buffer has been copied, so it can * be reused. * * The steps followed to append are explained in detail in the file * header. * * Whenever we write to a message, we increase msg->size, so it * reflects exactly how big the message is. This is needed so that if * we concatenate two messages before they can be sent, the code that * sends the messages can find the boundaries (and it will replace the * size with the real barker before sending). * * Note: * * Cold and warm reset payloads need to be sent as a single * payload, so we handle that. */ int i2400m_tx(struct i2400m *i2400m, const void *buf, size_t buf_len, enum i2400m_pt pl_type) { int result = -ENOSPC; struct device *dev = i2400m_dev(i2400m); unsigned long flags; size_t padded_len; void *ptr; bool try_head = false; unsigned is_singleton = pl_type == I2400M_PT_RESET_WARM || pl_type == I2400M_PT_RESET_COLD; d_fnstart(3, dev, "(i2400m %p skb %p [%zu bytes] pt %u)\n", i2400m, buf, buf_len, pl_type); padded_len = ALIGN(buf_len, I2400M_PL_ALIGN); d_printf(5, dev, "padded_len %zd buf_len %zd\n", padded_len, buf_len); /* If there is no current TX message, create one; if the * current one is out of payload slots or we have a singleton, * close it and start a new one */ spin_lock_irqsave(&i2400m->tx_lock, flags); /* If tx_buf is NULL, device is shutdown */ if (i2400m->tx_buf == NULL) { result = -ESHUTDOWN; goto error_tx_new; } try_new: if (unlikely(i2400m->tx_msg == NULL)) i2400m_tx_new(i2400m); else if (unlikely(!i2400m_tx_fits(i2400m) || (is_singleton && i2400m->tx_msg->num_pls != 0))) { d_printf(2, dev, "closing TX message (fits %u singleton " "%u num_pls %u)\n", i2400m_tx_fits(i2400m), is_singleton, i2400m->tx_msg->num_pls); i2400m_tx_close(i2400m); i2400m_tx_new(i2400m); } if (i2400m->tx_msg == NULL) goto error_tx_new; /* * Check if this skb will fit in the TX queue's current active * TX message. The total message size must not exceed the maximum * size of each message I2400M_TX_MSG_SIZE. If it exceeds, * close the current message and push this skb into the new message. */ if (i2400m->tx_msg->size + padded_len > I2400M_TX_MSG_SIZE) { d_printf(2, dev, "TX: message too big, going new\n"); i2400m_tx_close(i2400m); i2400m_tx_new(i2400m); } if (i2400m->tx_msg == NULL) goto error_tx_new; /* So we have a current message header; now append space for * the message -- if there is not enough, try the head */ ptr = i2400m_tx_fifo_push(i2400m, padded_len, i2400m->bus_tx_block_size, try_head); if (ptr == TAIL_FULL) { /* Tail is full, try head */ d_printf(2, dev, "pl append: tail full\n"); i2400m_tx_close(i2400m); i2400m_tx_skip_tail(i2400m); try_head = true; goto try_new; } else if (ptr == NULL) { /* All full */ result = -ENOSPC; d_printf(2, dev, "pl append: all full\n"); } else { /* Got space, copy it, set padding */ struct i2400m_msg_hdr *tx_msg = i2400m->tx_msg; unsigned num_pls = le16_to_cpu(tx_msg->num_pls); memcpy(ptr, buf, buf_len); memset(ptr + buf_len, 0xad, padded_len - buf_len); i2400m_pld_set(&tx_msg->pld[num_pls], buf_len, pl_type); d_printf(3, dev, "pld 0x%08x (type 0x%1x len 0x%04zx\n", le32_to_cpu(tx_msg->pld[num_pls].val), pl_type, buf_len); tx_msg->num_pls = le16_to_cpu(num_pls+1); tx_msg->size += padded_len; d_printf(2, dev, "TX: appended %zu b (up to %u b) pl #%u\n", padded_len, tx_msg->size, num_pls+1); d_printf(2, dev, "TX: appended hdr @%zu %zu b pl #%u @%zu %zu/%zu b\n", (void *)tx_msg - i2400m->tx_buf, (size_t)tx_msg->size, num_pls+1, ptr - i2400m->tx_buf, buf_len, padded_len); result = 0; if (is_singleton) i2400m_tx_close(i2400m); } error_tx_new: spin_unlock_irqrestore(&i2400m->tx_lock, flags); /* kick in most cases, except when the TX subsys is down, as * it might free space */ if (likely(result != -ESHUTDOWN)) i2400m->bus_tx_kick(i2400m); d_fnend(3, dev, "(i2400m %p skb %p [%zu bytes] pt %u) = %d\n", i2400m, buf, buf_len, pl_type, result); return result; } EXPORT_SYMBOL_GPL(i2400m_tx); /** * i2400m_tx_msg_get - Get the first TX message in the FIFO to start sending it * * @i2400m: device descriptors * @bus_size: where to place the size of the TX message * * Called by the bus-specific driver to get the first TX message at * the FIF that is ready for transmission. * * It sets the state in @i2400m to indicate the bus-specific driver is * transferring that message (i2400m->tx_msg_size). * * Once the transfer is completed, call i2400m_tx_msg_sent(). * * Notes: * * The size of the TX message to be transmitted might be smaller than * that of the TX message in the FIFO (in case the header was * shorter). Hence, we copy it in @bus_size, for the bus layer to * use. We keep the message's size in i2400m->tx_msg_size so that * when the bus later is done transferring we know how much to * advance the fifo. * * We collect statistics here as all the data is available and we * assume it is going to work [see i2400m_tx_msg_sent()]. */ struct i2400m_msg_hdr *i2400m_tx_msg_get(struct i2400m *i2400m, size_t *bus_size) { struct device *dev = i2400m_dev(i2400m); struct i2400m_msg_hdr *tx_msg, *tx_msg_moved; unsigned long flags, pls; d_fnstart(3, dev, "(i2400m %p bus_size %p)\n", i2400m, bus_size); spin_lock_irqsave(&i2400m->tx_lock, flags); tx_msg_moved = NULL; if (i2400m->tx_buf == NULL) goto out_unlock; skip: tx_msg_moved = NULL; if (i2400m->tx_in == i2400m->tx_out) { /* Empty FIFO? */ i2400m->tx_in = 0; i2400m->tx_out = 0; d_printf(2, dev, "TX: FIFO empty: resetting\n"); goto out_unlock; } tx_msg = i2400m->tx_buf + i2400m->tx_out % I2400M_TX_BUF_SIZE; if (tx_msg->size & I2400M_TX_SKIP) { /* skip? */ d_printf(2, dev, "TX: skip: msg @%zu (%zu b)\n", i2400m->tx_out % I2400M_TX_BUF_SIZE, (size_t) tx_msg->size & ~I2400M_TX_SKIP); i2400m->tx_out += tx_msg->size & ~I2400M_TX_SKIP; goto skip; } if (tx_msg->num_pls == 0) { /* No payloads? */ if (tx_msg == i2400m->tx_msg) { /* open, we are done */ d_printf(2, dev, "TX: FIFO empty: open msg w/o payloads @%zu\n", (void *) tx_msg - i2400m->tx_buf); tx_msg = NULL; goto out_unlock; } else { /* closed, skip it */ d_printf(2, dev, "TX: skip msg w/o payloads @%zu (%zu b)\n", (void *) tx_msg - i2400m->tx_buf, (size_t) tx_msg->size); i2400m->tx_out += tx_msg->size & ~I2400M_TX_SKIP; goto skip; } } if (tx_msg == i2400m->tx_msg) /* open msg? */ i2400m_tx_close(i2400m); /* Now we have a valid TX message (with payloads) to TX */ tx_msg_moved = (void *) tx_msg + tx_msg->offset; i2400m->tx_msg_size = tx_msg->size; *bus_size = tx_msg_moved->size; d_printf(2, dev, "TX: pid %d msg hdr at @%zu offset +@%zu " "size %zu bus_size %zu\n", current->pid, (void *) tx_msg - i2400m->tx_buf, (size_t) tx_msg->offset, (size_t) tx_msg->size, (size_t) tx_msg_moved->size); tx_msg_moved->barker = le32_to_cpu(I2400M_H2D_PREVIEW_BARKER); tx_msg_moved->sequence = le32_to_cpu(i2400m->tx_sequence++); pls = le32_to_cpu(tx_msg_moved->num_pls); i2400m->tx_pl_num += pls; /* Update stats */ if (pls > i2400m->tx_pl_max) i2400m->tx_pl_max = pls; if (pls < i2400m->tx_pl_min) i2400m->tx_pl_min = pls; i2400m->tx_num++; i2400m->tx_size_acc += *bus_size; if (*bus_size < i2400m->tx_size_min) i2400m->tx_size_min = *bus_size; if (*bus_size > i2400m->tx_size_max) i2400m->tx_size_max = *bus_size; out_unlock: spin_unlock_irqrestore(&i2400m->tx_lock, flags); d_fnstart(3, dev, "(i2400m %p bus_size %p [%zu]) = %p\n", i2400m, bus_size, *bus_size, tx_msg_moved); return tx_msg_moved; } EXPORT_SYMBOL_GPL(i2400m_tx_msg_get); /** * i2400m_tx_msg_sent - indicate the transmission of a TX message * * @i2400m: device descriptor * * Called by the bus-specific driver when a message has been sent; * this pops it from the FIFO; and as there is space, start the queue * in case it was stopped. * * Should be called even if the message send failed and we are * dropping this TX message. */ void i2400m_tx_msg_sent(struct i2400m *i2400m) { unsigned n; unsigned long flags; struct device *dev = i2400m_dev(i2400m); d_fnstart(3, dev, "(i2400m %p)\n", i2400m); spin_lock_irqsave(&i2400m->tx_lock, flags); if (i2400m->tx_buf == NULL) goto out_unlock; i2400m->tx_out += i2400m->tx_msg_size; d_printf(2, dev, "TX: sent %zu b\n", (size_t) i2400m->tx_msg_size); i2400m->tx_msg_size = 0; BUG_ON(i2400m->tx_out > i2400m->tx_in); /* level them FIFO markers off */ n = i2400m->tx_out / I2400M_TX_BUF_SIZE; i2400m->tx_out %= I2400M_TX_BUF_SIZE; i2400m->tx_in -= n * I2400M_TX_BUF_SIZE; out_unlock: spin_unlock_irqrestore(&i2400m->tx_lock, flags); d_fnend(3, dev, "(i2400m %p) = void\n", i2400m); } EXPORT_SYMBOL_GPL(i2400m_tx_msg_sent); /** * i2400m_tx_setup - Initialize the TX queue and infrastructure * * Make sure we reset the TX sequence to zero, as when this function * is called, the firmware has been just restarted. Same rational * for tx_in, tx_out, tx_msg_size and tx_msg. We reset them since * the memory for TX queue is reallocated. */ int i2400m_tx_setup(struct i2400m *i2400m) { int result = 0; void *tx_buf; unsigned long flags; /* Do this here only once -- can't do on * i2400m_hard_start_xmit() as we'll cause race conditions if * the WS was scheduled on another CPU */ INIT_WORK(&i2400m->wake_tx_ws, i2400m_wake_tx_work); tx_buf = kmalloc(I2400M_TX_BUF_SIZE, GFP_ATOMIC); if (tx_buf == NULL) { result = -ENOMEM; goto error_kmalloc; } /* * Fail the build if we can't fit at least two maximum size messages * on the TX FIFO [one being delivered while one is constructed]. */ BUILD_BUG_ON(2 * I2400M_TX_MSG_SIZE > I2400M_TX_BUF_SIZE); spin_lock_irqsave(&i2400m->tx_lock, flags); i2400m->tx_sequence = 0; i2400m->tx_in = 0; i2400m->tx_out = 0; i2400m->tx_msg_size = 0; i2400m->tx_msg = NULL; i2400m->tx_buf = tx_buf; spin_unlock_irqrestore(&i2400m->tx_lock, flags); /* Huh? the bus layer has to define this... */ BUG_ON(i2400m->bus_tx_block_size == 0); error_kmalloc: return result; } /** * i2400m_tx_release - Tear down the TX queue and infrastructure */ void i2400m_tx_release(struct i2400m *i2400m) { unsigned long flags; spin_lock_irqsave(&i2400m->tx_lock, flags); kfree(i2400m->tx_buf); i2400m->tx_buf = NULL; spin_unlock_irqrestore(&i2400m->tx_lock, flags); }
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