/*
* cx18 buffer queues
*
* Derived from ivtv-queue.c
*
* Copyright (C) 2007 Hans Verkuil <hverkuil@xs4all.nl>
* Copyright (C) 2008 Andy Walls <awalls@radix.net>
*
* 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.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
* 02111-1307 USA
*/
#include "cx18-driver.h"
#include "cx18-queue.h"
#include "cx18-streams.h"
#include "cx18-scb.h"
void cx18_buf_swap(struct cx18_buffer *buf)
{
int i;
for (i = 0; i < buf->bytesused; i += 4)
swab32s((u32 *)(buf->buf + i));
}
void cx18_queue_init(struct cx18_queue *q)
{
INIT_LIST_HEAD(&q->list);
atomic_set(&q->buffers, 0);
q->bytesused = 0;
}
struct cx18_queue *_cx18_enqueue(struct cx18_stream *s, struct cx18_buffer *buf,
struct cx18_queue *q, int to_front)
{
/* clear the buffer if it is not to be enqueued to the full queue */
if (q != &s->q_full) {
buf->bytesused = 0;
buf->readpos = 0;
buf->b_flags = 0;
buf->skipped = 0;
}
/* q_busy is restricted to a max buffer count imposed by firmware */
if (q == &s->q_busy &&
atomic_read(&q->buffers) >= CX18_MAX_FW_MDLS_PER_STREAM)
q = &s->q_free;
spin_lock(&q->lock);
if (to_front)
list_add(&buf->list, &q->list); /* LIFO */
else
list_add_tail(&buf->list, &q->list); /* FIFO */
q->bytesused += buf->bytesused - buf->readpos;
atomic_inc(&q->buffers);
spin_unlock(&q->lock);
return q;
}
struct cx18_buffer *cx18_dequeue(struct cx18_stream *s, struct cx18_queue *q)
{
struct cx18_buffer *buf = NULL;
spin_lock(&q->lock);
if (!list_empty(&q->list)) {
buf = list_first_entry(&q->list, struct cx18_buffer, list);
list_del_init(&buf->list);
q->bytesused -= buf->bytesused - buf->readpos;
buf->skipped = 0;
atomic_dec(&q->buffers);
}
spin_unlock(&q->lock);
return buf;
}
struct cx18_buffer *cx18_queue_get_buf(struct cx18_stream *s, u32 id,
u32 bytesused)
{
struct cx18 *cx = s->cx;
struct cx18_buffer *buf;
struct cx18_buffer *tmp;
struct cx18_buffer *ret = NULL;
LIST_HEAD(sweep_up);
/*
* We don't have to acquire multiple q locks here, because we are
* serialized by the single threaded work handler.
* Buffers from the firmware will thus remain in order as
* they are moved from q_busy to q_full or to the dvb ring buffer.
*/
spin_lock(&s->q_busy.lock);
list_for_each_entry_safe(buf, tmp, &s->q_busy.list, list) {
/*
* We should find what the firmware told us is done,
* right at the front of the queue. If we don't, we likely have
* missed a buffer done message from the firmware.
* Once we skip a buffer repeatedly, relative to the size of
* q_busy, we have high confidence we've missed it.
*/
if (buf->id != id) {
buf->skipped++;
if (buf->skipped >= atomic_read(&s->q_busy.buffers)-1) {
/* buffer must have fallen out of rotation */
CX18_WARN("Skipped %s, buffer %d, %d "
"times - it must have dropped out of "
"rotation\n", s->name, buf->id,
buf->skipped);
/* Sweep it up to put it back into rotation */
list_move_tail(&buf->list, &sweep_up);
atomic_dec(&s->q_busy.buffers);
}
continue;
}
/*
* We pull the desired buffer off of the queue here. Something
* will have to put it back on a queue later.
*/
list_del_init(&buf->list);
atomic_dec(&s->q_busy.buffers);
ret = buf;
break;
}
spin_unlock(&s->q_busy.lock);
/*
* We found the buffer for which we were looking. Get it ready for
* the caller to put on q_full or in the dvb ring buffer.
*/
if (ret != NULL) {
ret->bytesused = bytesused;
ret->skipped = 0;
/* readpos and b_flags were 0'ed when the buf went on q_busy */
cx18_buf_sync_for_cpu(s, ret);
if (s->type != CX18_ENC_STREAM_TYPE_TS)
set_bit(CX18_F_B_NEED_BUF_SWAP, &ret->b_flags);
}
/* Put any buffers the firmware is ignoring back into normal rotation */
list_for_each_entry_safe(buf, tmp, &sweep_up, list) {
list_del_init(&buf->list);
cx18_enqueue(s, buf, &s->q_free);
}
return ret;
}
/* Move all buffers of a queue to q_free, while flushing the buffers */
static void cx18_queue_flush(struct cx18_stream *s, struct cx18_queue *q)
{
struct cx18_buffer *buf;
if (q == &s->q_free)
return;
spin_lock(&q->lock);
while (!list_empty(&q->list)) {
buf = list_first_entry(&q->list, struct cx18_buffer, list);
list_move_tail(&buf->list, &s->q_free.list);
buf->bytesused = buf->readpos = buf->b_flags = buf->skipped = 0;
atomic_inc(&s->q_free.buffers);
}
cx18_queue_init(q);
spin_unlock(&q->lock);
}
void cx18_flush_queues(struct cx18_stream *s)
{
cx18_queue_flush(s, &s->q_busy);
cx18_queue_flush(s, &s->q_full);
}
int cx18_stream_alloc(struct cx18_stream *s)
{
struct cx18 *cx = s->cx;
int i;
if (s->buffers == 0)
return 0;
CX18_DEBUG_INFO("Allocate %s stream: %d x %d buffers (%dkB total)\n",
s->name, s->buffers, s->buf_size,
s->buffers * s->buf_size / 1024);
if (((char __iomem *)&cx->scb->cpu_mdl[cx->mdl_offset + s->buffers] -
(char __iomem *)cx->scb) > SCB_RESERVED_SIZE) {
unsigned bufsz = (((char __iomem *)cx->scb) + SCB_RESERVED_SIZE -
((char __iomem *)cx->scb->cpu_mdl));
CX18_ERR("Too many buffers, cannot fit in SCB area\n");
CX18_ERR("Max buffers = %zd\n",
bufsz / sizeof(struct cx18_mdl));
return -ENOMEM;
}
s->mdl_offset = cx->mdl_offset;
/* allocate stream buffers. Initially all buffers are in q_free. */
for (i = 0; i < s->buffers; i++) {
struct cx18_buffer *buf = kzalloc(sizeof(struct cx18_buffer),
GFP_KERNEL|__GFP_NOWARN);
if (buf == NULL)
break;
buf->buf = kmalloc(s->buf_size, GFP_KERNEL|__GFP_NOWARN);
if (buf->buf == NULL) {
kfree(buf);
break;
}
buf->id = cx->buffer_id++;
INIT_LIST_HEAD(&buf->list);
buf->dma_handle = pci_map_single(s->cx->pci_dev,
buf->buf, s->buf_size, s->dma);
cx18_buf_sync_for_cpu(s, buf);
cx18_enqueue(s, buf, &s->q_free);
}
if (i == s->buffers) {
cx->mdl_offset += s->buffers;
return 0;
}
CX18_ERR("Couldn't allocate buffers for %s stream\n", s->name);
cx18_stream_free(s);
return -ENOMEM;
}
void cx18_stream_free(struct cx18_stream *s)
{
struct cx18_buffer *buf;
/* move all buffers to q_free */
cx18_flush_queues(s);
/* empty q_free */
while ((buf = cx18_dequeue(s, &s->q_free))) {
pci_unmap_single(s->cx->pci_dev, buf->dma_handle,
s->buf_size, s->dma);
kfree(buf->buf);
kfree(buf);
}
}
