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busdma_bounce: Batch bounce page free operations when possible.

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Reviewed by:	imp
Differential Revision:	https://reviews.freebsd.org/D34968
This commit is contained in:
John Baldwin 2022-04-21 12:01:55 -07:00
parent d4ab3a8d4f
commit 92e40a9b92
1 changed files with 34 additions and 35 deletions
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69
sys/kern/subr_busdma_bounce.c
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@ -382,55 +382,54 @@ add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, vm_offset_t vaddr,
}
static void
free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage)
free_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map)
{
struct bus_dmamap *map;
struct bounce_page *bpage;
struct bounce_zone *bz;
bool schedule_thread;
u_int count;
if (STAILQ_EMPTY(&map->bpages))
return;
bz = dmat->bounce_zone;
bpage->datavaddr = 0;
bpage->datacount = 0;
if (dmat_flags(dmat) & BUS_DMA_KEEP_PG_OFFSET) {
/*
* Reset the bounce page to start at offset 0. Other uses
* of this bounce page may need to store a full page of
* data and/or assume it starts on a page boundary.
*/
bpage->vaddr &= ~PAGE_MASK;
bpage->busaddr &= ~PAGE_MASK;
count = 0;
schedule_thread = false;
STAILQ_FOREACH(bpage, &map->bpages, links) {
bpage->datavaddr = 0;
bpage->datacount = 0;
if (dmat_flags(dmat) & BUS_DMA_KEEP_PG_OFFSET) {
/*
* Reset the bounce page to start at offset 0.
* Other uses of this bounce page may need to
* store a full page of data and/or assume it
* starts on a page boundary.
*/
bpage->vaddr &= ~PAGE_MASK;
bpage->busaddr &= ~PAGE_MASK;
}
count++;
}
schedule_thread = false;
mtx_lock(&bounce_lock);
STAILQ_INSERT_HEAD(&bz->bounce_page_list, bpage, links);
bz->free_bpages++;
bz->active_bpages--;
if ((map = STAILQ_FIRST(&bz->bounce_map_waitinglist)) != NULL) {
if (reserve_bounce_pages(map->dmat, map, 1) == 0) {
STAILQ_REMOVE_HEAD(&bz->bounce_map_waitinglist, links);
STAILQ_INSERT_TAIL(&bounce_map_callbacklist,
map, links);
bz->total_deferred++;
schedule_thread = true;
}
STAILQ_CONCAT(&bz->bounce_page_list, &map->bpages);
bz->free_bpages += count;
bz->active_bpages -= count;
while ((map = STAILQ_FIRST(&bz->bounce_map_waitinglist)) != NULL) {
if (reserve_bounce_pages(map->dmat, map, 1) != 0)
break;
STAILQ_REMOVE_HEAD(&bz->bounce_map_waitinglist, links);
STAILQ_INSERT_TAIL(&bounce_map_callbacklist, map, links);
bz->total_deferred++;
schedule_thread = true;
}
mtx_unlock(&bounce_lock);
if (schedule_thread)
wakeup(&bounce_map_callbacklist);
}
static void
free_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map)
{
struct bounce_page *bpage;
while ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
STAILQ_REMOVE_HEAD(&map->bpages, links);
free_bounce_page(dmat, bpage);
}
}
static void
busdma_thread(void *dummy __unused)
{