From 52fcb3ecc6707f52dfe4297f96b7609d4ba517fb Mon Sep 17 00:00:00 2001 From: Andy Walls Date: Sun, 8 Nov 2009 23:45:24 -0300 Subject: V4L/DVB (13429): cx18: Add Memory Descriptor List (MDL) layer to buffer handling Add a Memory Descriptor List (MDL) layer to buffer handling to implement scatter-gather I/O. Currently there is still only 1 buffer per MDL. Signed-off-by: Andy Walls Signed-off-by: Mauro Carvalho Chehab --- drivers/media/video/cx18/cx18-queue.c | 316 +++++++++++++++++++++++++++------- 1 file changed, 249 insertions(+), 67 deletions(-) (limited to 'drivers/media/video/cx18/cx18-queue.c') diff --git a/drivers/media/video/cx18/cx18-queue.c b/drivers/media/video/cx18/cx18-queue.c index b9bd4ff5535e..c1a49ecf9d98 100644 --- a/drivers/media/video/cx18/cx18-queue.c +++ b/drivers/media/video/cx18/cx18-queue.c @@ -26,6 +26,7 @@ #include "cx18-queue.h" #include "cx18-streams.h" #include "cx18-scb.h" +#include "cx18-io.h" void cx18_buf_swap(struct cx18_buffer *buf) { @@ -35,6 +36,17 @@ void cx18_buf_swap(struct cx18_buffer *buf) swab32s((u32 *)(buf->buf + i)); } +void _cx18_mdl_swap(struct cx18_mdl *mdl) +{ + struct cx18_buffer *buf; + + list_for_each_entry(buf, &mdl->buf_list, list) { + if (buf->bytesused == 0) + break; + cx18_buf_swap(buf); + } +} + void cx18_queue_init(struct cx18_queue *q) { INIT_LIST_HEAD(&q->list); @@ -42,15 +54,16 @@ void cx18_queue_init(struct cx18_queue *q) q->bytesused = 0; } -struct cx18_queue *_cx18_enqueue(struct cx18_stream *s, struct cx18_buffer *buf, +struct cx18_queue *_cx18_enqueue(struct cx18_stream *s, struct cx18_mdl *mdl, struct cx18_queue *q, int to_front) { - /* clear the buffer if it is not to be enqueued to the full queue */ + /* clear the mdl 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; + mdl->bytesused = 0; + mdl->readpos = 0; + mdl->m_flags = 0; + mdl->skipped = 0; + mdl->curr_buf = NULL; } /* q_busy is restricted to a max buffer count imposed by firmware */ @@ -61,125 +74,270 @@ struct cx18_queue *_cx18_enqueue(struct cx18_stream *s, struct cx18_buffer *buf, spin_lock(&q->lock); if (to_front) - list_add(&buf->list, &q->list); /* LIFO */ + list_add(&mdl->list, &q->list); /* LIFO */ else - list_add_tail(&buf->list, &q->list); /* FIFO */ - q->bytesused += buf->bytesused - buf->readpos; + list_add_tail(&mdl->list, &q->list); /* FIFO */ + q->bytesused += mdl->bytesused - mdl->readpos; atomic_inc(&q->depth); spin_unlock(&q->lock); return q; } -struct cx18_buffer *cx18_dequeue(struct cx18_stream *s, struct cx18_queue *q) +struct cx18_mdl *cx18_dequeue(struct cx18_stream *s, struct cx18_queue *q) { - struct cx18_buffer *buf = NULL; + struct cx18_mdl *mdl = 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; + mdl = list_first_entry(&q->list, struct cx18_mdl, list); + list_del_init(&mdl->list); + q->bytesused -= mdl->bytesused - mdl->readpos; + mdl->skipped = 0; atomic_dec(&q->depth); } spin_unlock(&q->lock); - return buf; + return mdl; +} + +static void _cx18_mdl_set_buf_bytesused(struct cx18_stream *s, + struct cx18_mdl *mdl) +{ + struct cx18_buffer *buf; + u32 buf_size = s->buf_size; + u32 bytesused = mdl->bytesused; + + list_for_each_entry(buf, &mdl->buf_list, list) { + buf->readpos = 0; + if (bytesused >= buf_size) { + buf->bytesused = buf_size; + bytesused -= buf_size; + } else { + buf->bytesused = bytesused; + bytesused = 0; + } + } } -struct cx18_buffer *cx18_queue_get_buf(struct cx18_stream *s, u32 id, +static inline void cx18_mdl_set_buf_bytesused(struct cx18_stream *s, + struct cx18_mdl *mdl) +{ + struct cx18_buffer *buf; + + if (list_is_singular(&mdl->buf_list)) { + buf = list_first_entry(&mdl->buf_list, struct cx18_buffer, + list); + buf->bytesused = mdl->bytesused; + buf->readpos = 0; + } else { + _cx18_mdl_set_buf_bytesused(s, mdl); + } +} + +struct cx18_mdl *cx18_queue_get_mdl(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; + struct cx18_mdl *mdl; + struct cx18_mdl *tmp; + struct cx18_mdl *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 + * MDLs 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) { + list_for_each_entry_safe(mdl, 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 + * missed an mdl done message from the firmware. + * Once we skip an mdl 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.depth)-1) { - /* buffer must have fallen out of rotation */ - CX18_WARN("Skipped %s, buffer %d, %d " + if (mdl->id != id) { + mdl->skipped++; + if (mdl->skipped >= atomic_read(&s->q_busy.depth)-1) { + /* mdl must have fallen out of rotation */ + CX18_WARN("Skipped %s, MDL %d, %d " "times - it must have dropped out of " - "rotation\n", s->name, buf->id, - buf->skipped); + "rotation\n", s->name, mdl->id, + mdl->skipped); /* Sweep it up to put it back into rotation */ - list_move_tail(&buf->list, &sweep_up); + list_move_tail(&mdl->list, &sweep_up); atomic_dec(&s->q_busy.depth); } continue; } /* - * We pull the desired buffer off of the queue here. Something + * We pull the desired mdl off of the queue here. Something * will have to put it back on a queue later. */ - list_del_init(&buf->list); + list_del_init(&mdl->list); atomic_dec(&s->q_busy.depth); - ret = buf; + ret = mdl; break; } spin_unlock(&s->q_busy.lock); /* - * We found the buffer for which we were looking. Get it ready for + * We found the mdl 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); + /* 0'ed readpos, m_flags & curr_buf when mdl went on q_busy */ + cx18_mdl_set_buf_bytesused(s, ret); + cx18_mdl_sync_for_cpu(s, ret); if (s->type != CX18_ENC_STREAM_TYPE_TS) - set_bit(CX18_F_B_NEED_BUF_SWAP, &ret->b_flags); + set_bit(CX18_F_M_NEED_SWAP, &ret->m_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); + /* Put any mdls the firmware is ignoring back into normal rotation */ + list_for_each_entry_safe(mdl, tmp, &sweep_up, list) { + list_del_init(&mdl->list); + cx18_enqueue(s, mdl, &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) +/* Move all mdls of a queue, while flushing the mdl */ +static void cx18_queue_flush(struct cx18_stream *s, + struct cx18_queue *q_src, struct cx18_queue *q_dst) { - struct cx18_buffer *buf; + struct cx18_mdl *mdl; - if (q == &s->q_free) + /* It only makes sense to flush to q_free or q_idle */ + if (q_src == q_dst || q_dst == &s->q_full || q_dst == &s->q_busy) 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.depth); + spin_lock(&q_src->lock); + spin_lock(&q_dst->lock); + while (!list_empty(&q_src->list)) { + mdl = list_first_entry(&q_src->list, struct cx18_mdl, list); + list_move_tail(&mdl->list, &q_dst->list); + mdl->bytesused = 0; + mdl->readpos = 0; + mdl->m_flags = 0; + mdl->skipped = 0; + mdl->curr_buf = NULL; + atomic_inc(&q_dst->depth); } - cx18_queue_init(q); - spin_unlock(&q->lock); + cx18_queue_init(q_src); + spin_unlock(&q_src->lock); + spin_unlock(&q_dst->lock); } void cx18_flush_queues(struct cx18_stream *s) { - cx18_queue_flush(s, &s->q_busy); - cx18_queue_flush(s, &s->q_full); + cx18_queue_flush(s, &s->q_busy, &s->q_free); + cx18_queue_flush(s, &s->q_full, &s->q_free); +} + +/* + * Note, s->buf_pool is not protected by a lock, + * the stream better not have *anything* going on when calling this + */ +void cx18_unload_queues(struct cx18_stream *s) +{ + struct cx18_queue *q_idle = &s->q_idle; + struct cx18_mdl *mdl; + struct cx18_buffer *buf; + + /* Move all MDLS to q_idle */ + cx18_queue_flush(s, &s->q_busy, q_idle); + cx18_queue_flush(s, &s->q_full, q_idle); + cx18_queue_flush(s, &s->q_free, q_idle); + + /* Reset MDL id's and move all buffers back to the stream's buf_pool */ + spin_lock(&q_idle->lock); + list_for_each_entry(mdl, &q_idle->list, list) { + while (!list_empty(&mdl->buf_list)) { + buf = list_first_entry(&mdl->buf_list, + struct cx18_buffer, list); + list_move_tail(&buf->list, &s->buf_pool); + buf->bytesused = 0; + buf->readpos = 0; + } + mdl->id = s->mdl_base_idx; /* reset id to a "safe" value */ + /* all other mdl fields were cleared by cx18_queue_flush() */ + } + spin_unlock(&q_idle->lock); +} + +/* + * Note, s->buf_pool is not protected by a lock, + * the stream better not have *anything* going on when calling this + */ +void cx18_load_queues(struct cx18_stream *s) +{ + struct cx18 *cx = s->cx; + struct cx18_mdl *mdl; + struct cx18_buffer *buf; + int mdl_id; + int i; + + /* + * Attach buffers to MDLs, give the MDLs ids, and add MDLs to q_free + * Excess MDLs are left on q_idle + * Excess buffers are left in buf_pool and/or on an MDL in q_idle + */ + mdl_id = s->mdl_base_idx; + for (mdl = cx18_dequeue(s, &s->q_idle), i = s->bufs_per_mdl; + mdl != NULL && i == s->bufs_per_mdl; + mdl = cx18_dequeue(s, &s->q_idle)) { + + mdl->id = mdl_id; + + for (i = 0; i < s->bufs_per_mdl; i++) { + if (list_empty(&s->buf_pool)) + break; + + buf = list_first_entry(&s->buf_pool, struct cx18_buffer, + list); + list_move_tail(&buf->list, &mdl->buf_list); + + /* update the firmware's MDL array with this buffer */ + cx18_writel(cx, buf->dma_handle, + &cx->scb->cpu_mdl[mdl_id + i].paddr); + cx18_writel(cx, s->buf_size, + &cx->scb->cpu_mdl[mdl_id + i].length); + } + + if (i == s->bufs_per_mdl) + cx18_enqueue(s, mdl, &s->q_free); + else + cx18_push(s, mdl, &s->q_idle); /* not enough buffers */ + mdl_id += i; + } +} + +void _cx18_mdl_sync_for_cpu(struct cx18_stream *s, struct cx18_mdl *mdl) +{ + int dma = s->dma; + u32 buf_size = s->buf_size; + struct pci_dev *pci_dev = s->cx->pci_dev; + struct cx18_buffer *buf; + + list_for_each_entry(buf, &mdl->buf_list, list) + pci_dma_sync_single_for_cpu(pci_dev, buf->dma_handle, + buf_size, dma); +} + +void _cx18_mdl_sync_for_device(struct cx18_stream *s, struct cx18_mdl *mdl) +{ + int dma = s->dma; + u32 buf_size = s->buf_size; + struct pci_dev *pci_dev = s->cx->pci_dev; + struct cx18_buffer *buf; + + list_for_each_entry(buf, &mdl->buf_list, list) + pci_dma_sync_single_for_device(pci_dev, buf->dma_handle, + buf_size, dma); } int cx18_stream_alloc(struct cx18_stream *s) @@ -207,24 +365,40 @@ int cx18_stream_alloc(struct cx18_stream *s) s->mdl_base_idx = cx->free_mdl_idx; - /* allocate stream buffers. Initially all buffers are in q_free. */ + /* allocate stream buffers and MDLs */ for (i = 0; i < s->buffers; i++) { - struct cx18_buffer *buf = kzalloc(sizeof(struct cx18_buffer), - GFP_KERNEL|__GFP_NOWARN); + struct cx18_mdl *mdl; + struct cx18_buffer *buf; - if (buf == NULL) + /* 1 MDL per buffer to handle the worst & also default case */ + mdl = kzalloc(sizeof(struct cx18_mdl), GFP_KERNEL|__GFP_NOWARN); + if (mdl == NULL) break; + + buf = kzalloc(sizeof(struct cx18_buffer), + GFP_KERNEL|__GFP_NOWARN); + if (buf == NULL) { + kfree(mdl); + break; + } + buf->buf = kmalloc(s->buf_size, GFP_KERNEL|__GFP_NOWARN); if (buf->buf == NULL) { + kfree(mdl); kfree(buf); break; } - buf->id = cx->buffer_id++; + + INIT_LIST_HEAD(&mdl->list); + INIT_LIST_HEAD(&mdl->buf_list); + mdl->id = s->mdl_base_idx; /* a somewhat safe value */ + cx18_enqueue(s, mdl, &s->q_idle); + 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); + list_add_tail(&buf->list, &s->buf_pool); } if (i == s->buffers) { cx->free_mdl_idx += s->buffers; @@ -237,13 +411,21 @@ int cx18_stream_alloc(struct cx18_stream *s) void cx18_stream_free(struct cx18_stream *s) { + struct cx18_mdl *mdl; struct cx18_buffer *buf; - /* move all buffers to q_free */ - cx18_flush_queues(s); + /* move all buffers to buf_pool and all MDLs to q_idle */ + cx18_unload_queues(s); + + /* empty q_idle */ + while ((mdl = cx18_dequeue(s, &s->q_idle))) + kfree(mdl); + + /* empty buf_pool */ + while (!list_empty(&s->buf_pool)) { + buf = list_first_entry(&s->buf_pool, struct cx18_buffer, list); + list_del_init(&buf->list); - /* 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); -- cgit v1.2.1