diff options
Diffstat (limited to 'drivers/staging/wimax/i2400m/tx.c')
| -rw-r--r-- | drivers/staging/wimax/i2400m/tx.c | 1015 |
1 files changed, 0 insertions, 1015 deletions
diff --git a/drivers/staging/wimax/i2400m/tx.c b/drivers/staging/wimax/i2400m/tx.c deleted file mode 100644 index 8c01f42876ea..000000000000 --- a/drivers/staging/wimax/i2400m/tx.c +++ /dev/null @@ -1,1015 +0,0 @@ -/* - * 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 = struct_size(tx_msg, pld, le16_to_cpu(tx_msg->num_pls)); - 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 (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 - * - * @i2400m: device descriptor - * - * @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 = cpu_to_le16(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 = cpu_to_le32(I2400M_H2D_PREVIEW_BARKER); - tx_msg_moved->sequence = cpu_to_le32(i2400m->tx_sequence++); - - pls = le16_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 - * - * @i2400m: device descriptor - * - * 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); -} |