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authorThierry Reding <treding@nvidia.com>2022-03-24 11:30:25 +0100
committerThierry Reding <treding@nvidia.com>2022-04-06 15:12:36 +0200
commit3e9c4584336149146fe15cb5703fc10a2ca2d2a0 (patch)
treece6d362db2350799672bcb167c46d0105d7bade9
parentgpu: host1x: Fix a kernel-doc warning (diff)
downloadlinux-3e9c4584336149146fe15cb5703fc10a2ca2d2a0.tar.xz
linux-3e9c4584336149146fe15cb5703fc10a2ca2d2a0.zip
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 <jonathanh@nvidia.com> Tested-by: Jon Hunter <jonathanh@nvidia.com> Signed-off-by: Thierry Reding <treding@nvidia.com>
-rw-r--r--drivers/gpu/host1x/job.c4
-rw-r--r--include/linux/host1x.h5
2 files changed, 7 insertions, 2 deletions
diff --git a/drivers/gpu/host1x/job.c b/drivers/gpu/host1x/job.c
index 5e8c183167b7..b2761aa03b95 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 00278853eadf..c0bf4e581fe9 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;