From 5f1a233efee8f4c98985210e54f0746d7d6ade17 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Christian=20K=C3=B6nig?= Date: Tue, 14 Nov 2023 13:37:09 +0100 Subject: [PATCH] dma-buf: fix check in dma_resv_add_fence MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit commit 95ba893c9f4feb836ddce627efd0bb6af6667031 upstream. It's valid to add the same fence multiple times to a dma-resv object and we shouldn't need one extra slot for each. Signed-off-by: Christian König Reviewed-by: Thomas Hellström Fixes: a3f7c10a269d5 ("dma-buf/dma-resv: check if the new fence is really later") Cc: stable@vger.kernel.org # v5.19+ Link: https://patchwork.freedesktop.org/patch/msgid/20231115093035.1889-1-christian.koenig@amd.com Signed-off-by: Greg Kroah-Hartman --- drivers/dma-buf/dma-resv.c | 2 +- include/linux/dma-fence.h | 15 +++++++++++++++ 2 files changed, 16 insertions(+), 1 deletion(-) diff --git a/drivers/dma-buf/dma-resv.c b/drivers/dma-buf/dma-resv.c index 38b4110..eb8b733 100644 --- a/drivers/dma-buf/dma-resv.c +++ b/drivers/dma-buf/dma-resv.c @@ -301,7 +301,7 @@ void dma_resv_add_fence(struct dma_resv *obj, struct dma_fence *fence, dma_resv_list_entry(fobj, i, obj, &old, &old_usage); if ((old->context == fence->context && old_usage >= usage && - dma_fence_is_later(fence, old)) || + dma_fence_is_later_or_same(fence, old)) || dma_fence_is_signaled(old)) { dma_resv_list_set(fobj, i, fence, usage); dma_fence_put(old); diff --git a/include/linux/dma-fence.h b/include/linux/dma-fence.h index ebe78bd..b3772ed 100644 --- a/include/linux/dma-fence.h +++ b/include/linux/dma-fence.h @@ -499,6 +499,21 @@ static inline bool dma_fence_is_later(struct dma_fence *f1, } /** + * dma_fence_is_later_or_same - return true if f1 is later or same as f2 + * @f1: the first fence from the same context + * @f2: the second fence from the same context + * + * Returns true if f1 is chronologically later than f2 or the same fence. Both + * fences must be from the same context, since a seqno is not re-used across + * contexts. + */ +static inline bool dma_fence_is_later_or_same(struct dma_fence *f1, + struct dma_fence *f2) +{ + return f1 == f2 || dma_fence_is_later(f1, f2); +} + +/** * dma_fence_later - return the chronologically later fence * @f1: the first fence from the same context * @f2: the second fence from the same context -- 2.7.4