From: Thierry Reding Date: Thu, 24 Mar 2022 10:30:25 +0000 (+0100) Subject: gpu: host1x: Do not use mapping cache for job submissions X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=3e9c4584336149146fe15cb5703fc10a2ca2d2a0;p=linux.git gpu: host1x: Do not use mapping cache for job submissions Buffer mappings used in job submissions are usually small and not rapidly reused as opposed to framebuffers (which are usually large and rapidly reused, for example when page-flipping between double-buffered framebuffers). Avoid going through the mapping cache for these buffers since the cache would also lead to leaks if nobody is ever releasing the cache's last reference. For DRM/KMS these last references are dropped when the framebuffers are removed and therefore no longer needed. While at it, also add a note about the need to explicitly remove the final reference to the mapping in the cache. Reviewed-by: Jon Hunter Tested-by: Jon Hunter Signed-off-by: Thierry Reding --- diff --git a/drivers/gpu/host1x/job.c b/drivers/gpu/host1x/job.c index 5e8c183167b7d..b2761aa03b95c 100644 --- a/drivers/gpu/host1x/job.c +++ b/drivers/gpu/host1x/job.c @@ -175,7 +175,7 @@ static unsigned int pin_job(struct host1x *host, struct host1x_job *job) goto unpin; } - map = host1x_bo_pin(dev, bo, direction, &client->cache); + map = host1x_bo_pin(dev, bo, direction, NULL); if (IS_ERR(map)) { err = PTR_ERR(map); goto unpin; @@ -222,7 +222,7 @@ static unsigned int pin_job(struct host1x *host, struct host1x_job *job) goto unpin; } - map = host1x_bo_pin(host->dev, g->bo, DMA_TO_DEVICE, &host->cache); + map = host1x_bo_pin(host->dev, g->bo, DMA_TO_DEVICE, NULL); if (IS_ERR(map)) { err = PTR_ERR(map); goto unpin; diff --git a/include/linux/host1x.h b/include/linux/host1x.h index 00278853eadf0..c0bf4e581fe9d 100644 --- a/include/linux/host1x.h +++ b/include/linux/host1x.h @@ -31,6 +31,11 @@ u64 host1x_get_dma_mask(struct host1x *host1x); * struct host1x_bo_cache - host1x buffer object cache * @mappings: list of mappings * @lock: synchronizes accesses to the list of mappings + * + * Note that entries are not periodically evicted from this cache and instead need to be + * explicitly released. This is used primarily for DRM/KMS where the cache's reference is + * released when the last reference to a buffer object represented by a mapping in this + * cache is dropped. */ struct host1x_bo_cache { struct list_head mappings;