1014 lines
37 KiB
C
1014 lines
37 KiB
C
/*
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* Intel Wireless WiMAX Connection 2400m
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* Generic (non-bus specific) TX handling
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*
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*
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* Copyright (C) 2007-2008 Intel Corporation. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* * Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* * Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in
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* the documentation and/or other materials provided with the
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* distribution.
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* * Neither the name of Intel Corporation nor the names of its
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* contributors may be used to endorse or promote products derived
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* from this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*
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*
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* Intel Corporation <linux-wimax@intel.com>
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* Yanir Lubetkin <yanirx.lubetkin@intel.com>
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* - Initial implementation
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*
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* Intel Corporation <linux-wimax@intel.com>
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* Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
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* - Rewritten to use a single FIFO to lower the memory allocation
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* pressure and optimize cache hits when copying to the queue, as
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* well as splitting out bus-specific code.
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*
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*
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* Implements data transmission to the device; this is done through a
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* software FIFO, as data/control frames can be coalesced (while the
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* device is reading the previous tx transaction, others accumulate).
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*
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* A FIFO is used because at the end it is resource-cheaper that trying
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* to implement scatter/gather over USB. As well, most traffic is going
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* to be download (vs upload).
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*
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* The format for sending/receiving data to/from the i2400m is
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* described in detail in rx.c:PROTOCOL FORMAT. In here we implement
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* the transmission of that. This is split between a bus-independent
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* part that just prepares everything and a bus-specific part that
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* does the actual transmission over the bus to the device (in the
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* bus-specific driver).
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*
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*
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* The general format of a device-host transaction is MSG-HDR, PLD1,
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* PLD2...PLDN, PL1, PL2,...PLN, PADDING.
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*
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* Because we need the send payload descriptors and then payloads and
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* because it is kind of expensive to do scatterlists in USB (one URB
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* per node), it becomes cheaper to append all the data to a FIFO
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* (copying to a FIFO potentially in cache is cheaper).
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*
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* Then the bus-specific code takes the parts of that FIFO that are
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* written and passes them to the device.
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*
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* So the concepts to keep in mind there are:
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*
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* We use a FIFO to queue the data in a linear buffer. We first append
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* a MSG-HDR, space for I2400M_TX_PLD_MAX payload descriptors and then
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* go appending payloads until we run out of space or of payload
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* descriptors. Then we append padding to make the whole transaction a
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* multiple of i2400m->bus_tx_block_size (as defined by the bus layer).
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*
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* - A TX message: a combination of a message header, payload
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* descriptors and payloads.
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*
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* Open: it is marked as active (i2400m->tx_msg is valid) and we
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* can keep adding payloads to it.
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*
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* Closed: we are not appending more payloads to this TX message
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* (exahusted space in the queue, too many payloads or
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* whichever). We have appended padding so the whole message
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* length is aligned to i2400m->bus_tx_block_size (as set by the
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* bus/transport layer).
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*
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* - Most of the time we keep a TX message open to which we append
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* payloads.
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*
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* - If we are going to append and there is no more space (we are at
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* the end of the FIFO), we close the message, mark the rest of the
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* FIFO space unusable (skip_tail), create a new message at the
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* beginning of the FIFO (if there is space) and append the message
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* there.
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*
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* This is because we need to give linear TX messages to the bus
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* engine. So we don't write a message to the remaining FIFO space
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* until the tail and continue at the head of it.
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*
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* - We overload one of the fields in the message header to use it as
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* 'size' of the TX message, so we can iterate over them. It also
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* contains a flag that indicates if we have to skip it or not.
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* When we send the buffer, we update that to its real on-the-wire
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* value.
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*
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* - The MSG-HDR PLD1...PLD2 stuff has to be a size multiple of 16.
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*
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* It follows that if MSG-HDR says we have N messages, the whole
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* header + descriptors is 16 + 4*N; for those to be a multiple of
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* 16, it follows that N can be 4, 8, 12, ... (32, 48, 64, 80...
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* bytes).
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*
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* So if we have only 1 payload, we have to submit a header that in
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* all truth has space for 4.
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*
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* The implication is that we reserve space for 12 (64 bytes); but
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* if we fill up only (eg) 2, our header becomes 32 bytes only. So
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* the TX engine has to shift those 32 bytes of msg header and 2
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* payloads and padding so that right after it the payloads start
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* and the TX engine has to know about that.
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*
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* It is cheaper to move the header up than the whole payloads down.
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*
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* We do this in i2400m_tx_close(). See 'i2400m_msg_hdr->offset'.
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*
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* - Each payload has to be size-padded to 16 bytes; before appending
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* it, we just do it.
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*
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* - The whole message has to be padded to i2400m->bus_tx_block_size;
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* we do this at close time. Thus, when reserving space for the
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* payload, we always make sure there is also free space for this
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* padding that sooner or later will happen.
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*
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* When we append a message, we tell the bus specific code to kick in
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* TXs. It will TX (in parallel) until the buffer is exhausted--hence
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* the lockin we do. The TX code will only send a TX message at the
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* time (which remember, might contain more than one payload). Of
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* course, when the bus-specific driver attempts to TX a message that
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* is still open, it gets closed first.
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*
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* Gee, this is messy; well a picture. In the example below we have a
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* partially full FIFO, with a closed message ready to be delivered
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* (with a moved message header to make sure it is size-aligned to
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* 16), TAIL room that was unusable (and thus is marked with a message
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* header that says 'skip this') and at the head of the buffer, an
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* incomplete message with a couple of payloads.
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*
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* N ___________________________________________________
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* | |
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* | TAIL room |
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* | |
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* | msg_hdr to skip (size |= 0x80000) |
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* |---------------------------------------------------|-------
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* | | /|\
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* | | |
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* | TX message padding | |
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* | | |
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* | | |
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* |- - - - - - - - - - - - - - - - - - - - - - - - - -| |
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* | | |
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* | payload 1 | |
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* | | N * tx_block_size
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* | | |
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* |- - - - - - - - - - - - - - - - - - - - - - - - - -| |
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* | | |
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* | payload 1 | |
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* | | |
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* | | |
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* |- - - - - - - - - - - - - - - - - - - - - - - - - -|- -|- - - -
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* | padding 3 /|\ | | /|\
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* | padding 2 | | | |
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* | pld 1 32 bytes (2 * 16) | | |
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* | pld 0 | | | |
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* | moved msg_hdr \|/ | \|/ |
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* |- - - - - - - - - - - - - - - - - - - - - - - - - -|- - - |
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* | | _PLD_SIZE
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* | unused | |
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* | | |
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* |- - - - - - - - - - - - - - - - - - - - - - - - - -| |
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* | msg_hdr (size X) [this message is closed] | \|/
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* |===================================================|========== <=== OUT
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* | |
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* | |
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* | |
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* | Free rooom |
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* | |
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* | |
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* | |
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* | |
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* | |
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* | |
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* | |
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* | |
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* | |
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* |===================================================|========== <=== IN
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* | |
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* | |
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* | |
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* | |
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* | payload 1 |
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* | |
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* | |
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* |- - - - - - - - - - - - - - - - - - - - - - - - - -|
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* | |
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* | payload 0 |
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* | |
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* | |
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* |- - - - - - - - - - - - - - - - - - - - - - - - - -|
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* | pld 11 /|\ |
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* | ... | |
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* | pld 1 64 bytes (2 * 16) |
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* | pld 0 | |
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* | msg_hdr (size X) \|/ [message is open] |
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* 0 ---------------------------------------------------
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*
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*
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* ROADMAP
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*
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* i2400m_tx_setup() Called by i2400m_setup
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* i2400m_tx_release() Called by i2400m_release()
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*
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* i2400m_tx() Called to send data or control frames
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* i2400m_tx_fifo_push() Allocates append-space in the FIFO
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* i2400m_tx_new() Opens a new message in the FIFO
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* i2400m_tx_fits() Checks if a new payload fits in the message
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* i2400m_tx_close() Closes an open message in the FIFO
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* i2400m_tx_skip_tail() Marks unusable FIFO tail space
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* i2400m->bus_tx_kick()
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*
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* Now i2400m->bus_tx_kick() is the the bus-specific driver backend
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* implementation; that would do:
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*
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* i2400m->bus_tx_kick()
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* i2400m_tx_msg_get() Gets first message ready to go
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* ...sends it...
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* i2400m_tx_msg_sent() Ack the message is sent; repeat from
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* _tx_msg_get() until it returns NULL
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* (FIFO empty).
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*/
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#include <linux/netdevice.h>
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#include <linux/slab.h>
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#include <linux/export.h>
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#include "i2400m.h"
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#define D_SUBMODULE tx
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#include "debug-levels.h"
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enum {
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/**
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* TX Buffer size
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*
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* Doc says maximum transaction is 16KiB. If we had 16KiB en
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* route and 16KiB being queued, it boils down to needing
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* 32KiB.
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* 32KiB is insufficient for 1400 MTU, hence increasing
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* tx buffer size to 64KiB.
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*/
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I2400M_TX_BUF_SIZE = 65536,
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/**
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* Message header and payload descriptors have to be 16
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* aligned (16 + 4 * N = 16 * M). If we take that average sent
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* packets are MTU size (~1400-~1500) it follows that we could
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* fit at most 10-11 payloads in one transaction. To meet the
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* alignment requirement, that means we need to leave space
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* for 12 (64 bytes). To simplify, we leave space for that. If
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* at the end there are less, we pad up to the nearest
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* multiple of 16.
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*/
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/*
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* According to Intel Wimax i3200, i5x50 and i6x50 specification
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* documents, the maximum number of payloads per message can be
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* up to 60. Increasing the number of payloads to 60 per message
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* helps to accommodate smaller payloads in a single transaction.
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*/
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I2400M_TX_PLD_MAX = 60,
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I2400M_TX_PLD_SIZE = sizeof(struct i2400m_msg_hdr)
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+ I2400M_TX_PLD_MAX * sizeof(struct i2400m_pld),
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I2400M_TX_SKIP = 0x80000000,
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/*
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* According to Intel Wimax i3200, i5x50 and i6x50 specification
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* documents, the maximum size of each message can be up to 16KiB.
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*/
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I2400M_TX_MSG_SIZE = 16384,
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};
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#define TAIL_FULL ((void *)~(unsigned long)NULL)
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/*
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* Calculate how much tail room is available
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*
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* Note the trick here. This path is ONLY caleed for Case A (see
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* i2400m_tx_fifo_push() below), where we have:
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*
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* Case A
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* N ___________
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* | tail room |
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* | |
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* |<- IN ->|
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* | |
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* | data |
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* | |
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* |<- OUT ->|
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* | |
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* | head room |
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* 0 -----------
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*
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* When calculating the tail_room, tx_in might get to be zero if
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* i2400m->tx_in is right at the end of the buffer (really full
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* buffer) if there is no head room. In this case, tail_room would be
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* I2400M_TX_BUF_SIZE, although it is actually zero. Hence the final
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* mod (%) operation. However, when doing this kind of optimization,
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* i2400m->tx_in being zero would fail, so we treat is an a special
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* case.
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*/
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static inline
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size_t __i2400m_tx_tail_room(struct i2400m *i2400m)
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{
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size_t tail_room;
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size_t tx_in;
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if (unlikely(i2400m->tx_in == 0))
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return I2400M_TX_BUF_SIZE;
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tx_in = i2400m->tx_in % I2400M_TX_BUF_SIZE;
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tail_room = I2400M_TX_BUF_SIZE - tx_in;
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tail_room %= I2400M_TX_BUF_SIZE;
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return tail_room;
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}
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/*
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* Allocate @size bytes in the TX fifo, return a pointer to it
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*
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* @i2400m: device descriptor
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* @size: size of the buffer we need to allocate
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* @padding: ensure that there is at least this many bytes of free
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* contiguous space in the fifo. This is needed because later on
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* we might need to add padding.
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* @try_head: specify either to allocate head room or tail room space
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* in the TX FIFO. This boolean is required to avoids a system hang
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* due to an infinite loop caused by i2400m_tx_fifo_push().
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* The caller must always try to allocate tail room space first by
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* calling this routine with try_head = 0. In case if there
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* is not enough tail room space but there is enough head room space,
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* (i2400m_tx_fifo_push() returns TAIL_FULL) try to allocate head
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* room space, by calling this routine again with try_head = 1.
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*
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* Returns:
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*
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* Pointer to the allocated space. NULL if there is no
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* space. TAIL_FULL if there is no space at the tail but there is at
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* the head (Case B below).
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*
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* These are the two basic cases we need to keep an eye for -- it is
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* much better explained in linux/kernel/kfifo.c, but this code
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* basically does the same. No rocket science here.
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*
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* Case A Case B
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* N ___________ ___________
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* | tail room | | data |
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* | | | |
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* |<- IN ->| |<- OUT ->|
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* | | | |
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* | data | | room |
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* | | | |
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* |<- OUT ->| |<- IN ->|
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* | | | |
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* | head room | | data |
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* 0 ----------- -----------
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*
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* We allocate only *contiguous* space.
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*
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* We can allocate only from 'room'. In Case B, it is simple; in case
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* A, we only try from the tail room; if it is not enough, we just
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* fail and return TAIL_FULL and let the caller figure out if we wants to
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* skip the tail room and try to allocate from the head.
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*
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* There is a corner case, wherein i2400m_tx_new() can get into
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* an infinite loop calling i2400m_tx_fifo_push().
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* In certain situations, tx_in would have reached on the top of TX FIFO
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* and i2400m_tx_tail_room() returns 0, as described below:
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*
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* N ___________ tail room is zero
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* |<- IN ->|
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* | |
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* | |
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* | |
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* | data |
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* |<- OUT ->|
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* | |
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* | |
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* | head room |
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* 0 -----------
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* During such a time, where tail room is zero in the TX FIFO and if there
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* is a request to add a payload to TX FIFO, which calls:
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* i2400m_tx()
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* ->calls i2400m_tx_close()
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* ->calls i2400m_tx_skip_tail()
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* goto try_new;
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* ->calls i2400m_tx_new()
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* |----> [try_head:]
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* infinite loop | ->calls i2400m_tx_fifo_push()
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* | if (tail_room < needed)
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* | if (head_room => needed)
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* | return TAIL_FULL;
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* |<---- goto try_head;
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*
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* i2400m_tx() calls i2400m_tx_close() to close the message, since there
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* is no tail room to accommodate the payload and calls
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* i2400m_tx_skip_tail() to skip the tail space. Now i2400m_tx() calls
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* i2400m_tx_new() to allocate space for new message header calling
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* i2400m_tx_fifo_push() that returns TAIL_FULL, since there is no tail space
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* to accommodate the message header, but there is enough head space.
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* The i2400m_tx_new() keeps re-retrying by calling i2400m_tx_fifo_push()
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* ending up in a loop causing system freeze.
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*
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* This corner case is avoided by using a try_head boolean,
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* as an argument to i2400m_tx_fifo_push().
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*
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* Note:
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*
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* Assumes i2400m->tx_lock is taken, and we use that as a barrier
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*
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* The indexes keep increasing and we reset them to zero when we
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* pop data off the queue
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*/
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static
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void *i2400m_tx_fifo_push(struct i2400m *i2400m, size_t size,
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size_t padding, bool try_head)
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{
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struct device *dev = i2400m_dev(i2400m);
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size_t room, tail_room, needed_size;
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void *ptr;
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needed_size = size + padding;
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room = I2400M_TX_BUF_SIZE - (i2400m->tx_in - i2400m->tx_out);
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if (room < needed_size) { /* this takes care of Case B */
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d_printf(2, dev, "fifo push %zu/%zu: no space\n",
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size, padding);
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return NULL;
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}
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/* Is there space at the tail? */
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tail_room = __i2400m_tx_tail_room(i2400m);
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if (!try_head && tail_room < needed_size) {
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/*
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* 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);
|
|
}
|