From 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 Mon Sep 17 00:00:00 2001 From: Yunhong Jiang Date: Tue, 4 Aug 2015 12:17:53 -0700 Subject: Add the rt linux 4.1.3-rt3 as base Import the rt linux 4.1.3-rt3 as OPNFV kvm base. It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and the base is: commit 0917f823c59692d751951bf5ea699a2d1e2f26a2 Author: Sebastian Andrzej Siewior Date: Sat Jul 25 12:13:34 2015 +0200 Prepare v4.1.3-rt3 Signed-off-by: Sebastian Andrzej Siewior We lose all the git history this way and it's not good. We should apply another opnfv project repo in future. Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423 Signed-off-by: Yunhong Jiang --- kernel/drivers/staging/fwserial/dma_fifo.c | 303 +++++++++++++++++++++++++++++ 1 file changed, 303 insertions(+) create mode 100644 kernel/drivers/staging/fwserial/dma_fifo.c (limited to 'kernel/drivers/staging/fwserial/dma_fifo.c') diff --git a/kernel/drivers/staging/fwserial/dma_fifo.c b/kernel/drivers/staging/fwserial/dma_fifo.c new file mode 100644 index 000000000..027906249 --- /dev/null +++ b/kernel/drivers/staging/fwserial/dma_fifo.c @@ -0,0 +1,303 @@ +/* + * DMA-able FIFO implementation + * + * Copyright (C) 2012 Peter Hurley + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include +#include +#include +#include + +#include "dma_fifo.h" + +#ifdef DEBUG_TRACING +#define df_trace(s, args...) pr_debug(s, ##args) +#else +#define df_trace(s, args...) +#endif + +#define FAIL(fifo, condition, format...) ({ \ + fifo->corrupt = !!(condition); \ + WARN(fifo->corrupt, format); \ +}) + +/* + * private helper fn to determine if check is in open interval (lo,hi) + */ +static bool addr_check(unsigned check, unsigned lo, unsigned hi) +{ + return check - (lo + 1) < (hi - 1) - lo; +} + +/** + * dma_fifo_init: initialize the fifo to a valid but inoperative state + * @fifo: address of in-place "struct dma_fifo" object + */ +void dma_fifo_init(struct dma_fifo *fifo) +{ + memset(fifo, 0, sizeof(*fifo)); + INIT_LIST_HEAD(&fifo->pending); +} + +/** + * dma_fifo_alloc - initialize and allocate dma_fifo + * @fifo: address of in-place "struct dma_fifo" object + * @size: 'apparent' size, in bytes, of fifo + * @align: dma alignment to maintain (should be at least cpu cache alignment), + * must be power of 2 + * @tx_limit: maximum # of bytes transmissable per dma (rounded down to + * multiple of alignment, but at least align size) + * @open_limit: maximum # of outstanding dma transactions allowed + * @gfp_mask: get_free_pages mask, passed to kmalloc() + * + * The 'apparent' size will be rounded up to next greater aligned size. + * Returns 0 if no error, otherwise an error code + */ +int dma_fifo_alloc(struct dma_fifo *fifo, int size, unsigned align, + int tx_limit, int open_limit, gfp_t gfp_mask) +{ + int capacity; + + if (!is_power_of_2(align) || size < 0) + return -EINVAL; + + size = round_up(size, align); + capacity = size + align * open_limit + align * DMA_FIFO_GUARD; + fifo->data = kmalloc(capacity, gfp_mask); + if (!fifo->data) + return -ENOMEM; + + fifo->in = 0; + fifo->out = 0; + fifo->done = 0; + fifo->size = size; + fifo->avail = size; + fifo->align = align; + fifo->tx_limit = max_t(int, round_down(tx_limit, align), align); + fifo->open = 0; + fifo->open_limit = open_limit; + fifo->guard = size + align * open_limit; + fifo->capacity = capacity; + fifo->corrupt = 0; + + return 0; +} + +/** + * dma_fifo_free - frees the fifo + * @fifo: address of in-place "struct dma_fifo" to free + * + * Also reinits the fifo to a valid but inoperative state. This + * allows the fifo to be reused with a different target requiring + * different fifo parameters. + */ +void dma_fifo_free(struct dma_fifo *fifo) +{ + struct dma_pending *pending, *next; + + if (fifo->data == NULL) + return; + + list_for_each_entry_safe(pending, next, &fifo->pending, link) + list_del_init(&pending->link); + kfree(fifo->data); + fifo->data = NULL; +} + +/** + * dma_fifo_reset - dumps the fifo contents and reinits for reuse + * @fifo: address of in-place "struct dma_fifo" to reset + */ +void dma_fifo_reset(struct dma_fifo *fifo) +{ + struct dma_pending *pending, *next; + + if (fifo->data == NULL) + return; + + list_for_each_entry_safe(pending, next, &fifo->pending, link) + list_del_init(&pending->link); + fifo->in = 0; + fifo->out = 0; + fifo->done = 0; + fifo->avail = fifo->size; + fifo->open = 0; + fifo->corrupt = 0; +} + +/** + * dma_fifo_in - copies data into the fifo + * @fifo: address of in-place "struct dma_fifo" to write to + * @src: buffer to copy from + * @n: # of bytes to copy + * + * Returns the # of bytes actually copied, which can be less than requested if + * the fifo becomes full. If < 0, return is error code. + */ +int dma_fifo_in(struct dma_fifo *fifo, const void *src, int n) +{ + int ofs, l; + + if (fifo->data == NULL) + return -ENOENT; + if (fifo->corrupt) + return -ENXIO; + + if (n > fifo->avail) + n = fifo->avail; + if (n <= 0) + return 0; + + ofs = fifo->in % fifo->capacity; + l = min(n, fifo->capacity - ofs); + memcpy(fifo->data + ofs, src, l); + memcpy(fifo->data, src + l, n - l); + + if (FAIL(fifo, addr_check(fifo->done, fifo->in, fifo->in + n) || + fifo->avail < n, + "fifo corrupt: in:%u out:%u done:%u n:%d avail:%d", + fifo->in, fifo->out, fifo->done, n, fifo->avail)) + return -ENXIO; + + fifo->in += n; + fifo->avail -= n; + + df_trace("in:%u out:%u done:%u n:%d avail:%d", fifo->in, fifo->out, + fifo->done, n, fifo->avail); + + return n; +} + +/** + * dma_fifo_out_pend - gets address/len of next avail read and marks as pended + * @fifo: address of in-place "struct dma_fifo" to read from + * @pended: address of structure to fill with read address/len + * The data/len fields will be NULL/0 if no dma is pended. + * + * Returns the # of used bytes remaining in fifo (ie, if > 0, more data + * remains in the fifo that was not pended). If < 0, return is error code. + */ +int dma_fifo_out_pend(struct dma_fifo *fifo, struct dma_pending *pended) +{ + unsigned len, n, ofs, l, limit; + + if (fifo->data == NULL) + return -ENOENT; + if (fifo->corrupt) + return -ENXIO; + + pended->len = 0; + pended->data = NULL; + pended->out = fifo->out; + + len = fifo->in - fifo->out; + if (!len) + return -ENODATA; + if (fifo->open == fifo->open_limit) + return -EAGAIN; + + n = len; + ofs = fifo->out % fifo->capacity; + l = fifo->capacity - ofs; + limit = min_t(unsigned, l, fifo->tx_limit); + if (n > limit) { + n = limit; + fifo->out += limit; + } else if (ofs + n > fifo->guard) { + fifo->out += l; + fifo->in = fifo->out; + } else { + fifo->out += round_up(n, fifo->align); + fifo->in = fifo->out; + } + + df_trace("in: %u out: %u done: %u n: %d len: %u avail: %d", fifo->in, + fifo->out, fifo->done, n, len, fifo->avail); + + pended->len = n; + pended->data = fifo->data + ofs; + pended->next = fifo->out; + list_add_tail(&pended->link, &fifo->pending); + ++fifo->open; + + if (FAIL(fifo, fifo->open > fifo->open_limit, + "past open limit:%d (limit:%d)", + fifo->open, fifo->open_limit)) + return -ENXIO; + if (FAIL(fifo, fifo->out & (fifo->align - 1), + "fifo out unaligned:%u (align:%u)", + fifo->out, fifo->align)) + return -ENXIO; + + return len - n; +} + +/** + * dma_fifo_out_complete - marks pended dma as completed + * @fifo: address of in-place "struct dma_fifo" which was read from + * @complete: address of structure for previously pended dma to mark completed + */ +int dma_fifo_out_complete(struct dma_fifo *fifo, struct dma_pending *complete) +{ + struct dma_pending *pending, *next, *tmp; + + if (fifo->data == NULL) + return -ENOENT; + if (fifo->corrupt) + return -ENXIO; + if (list_empty(&fifo->pending) && fifo->open == 0) + return -EINVAL; + + if (FAIL(fifo, list_empty(&fifo->pending) != (fifo->open == 0), + "pending list disagrees with open count:%d", + fifo->open)) + return -ENXIO; + + tmp = complete->data; + *tmp = *complete; + list_replace(&complete->link, &tmp->link); + dp_mark_completed(tmp); + + /* Only update the fifo in the original pended order */ + list_for_each_entry_safe(pending, next, &fifo->pending, link) { + if (!dp_is_completed(pending)) { + df_trace("still pending: saved out: %u len: %d", + pending->out, pending->len); + break; + } + + if (FAIL(fifo, pending->out != fifo->done || + addr_check(fifo->in, fifo->done, pending->next), + "in:%u out:%u done:%u saved:%u next:%u", + fifo->in, fifo->out, fifo->done, pending->out, + pending->next)) + return -ENXIO; + + list_del_init(&pending->link); + fifo->done = pending->next; + fifo->avail += pending->len; + --fifo->open; + + df_trace("in: %u out: %u done: %u len: %u avail: %d", fifo->in, + fifo->out, fifo->done, pending->len, fifo->avail); + } + + if (FAIL(fifo, fifo->open < 0, "open dma:%d < 0", fifo->open)) + return -ENXIO; + if (FAIL(fifo, fifo->avail > fifo->size, "fifo avail:%d > size:%d", + fifo->avail, fifo->size)) + return -ENXIO; + + return 0; +} -- cgit 1.2.3-korg