From b312d8ca3a7cebe19941d969a51f2b7f899b81e2 Mon Sep 17 00:00:00 2001 From: Christian König Date: Wed, 14 Nov 2018 16:11:06 +0100 Subject: dma-buf: make fence sequence numbers 64 bit v2 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit For a lot of use cases we need 64bit sequence numbers. Currently drivers overload the dma_fence structure to store the additional bits. Stop doing that and make the sequence number in the dma_fence always 64bit. For compatibility with hardware which can do only 32bit sequences the comparisons in __dma_fence_is_later only takes the lower 32bits as significant when the upper 32bits are all zero. v2: change the logic in __dma_fence_is_later Signed-off-by: Christian König Reviewed-by: Chunming Zhou Link: https://patchwork.freedesktop.org/patch/266927/ --- include/linux/dma-fence.h | 22 +++++++++++++++------- 1 file changed, 15 insertions(+), 7 deletions(-) (limited to 'include/linux/dma-fence.h') diff --git a/include/linux/dma-fence.h b/include/linux/dma-fence.h index 999e4b104410..6b788467b2e3 100644 --- a/include/linux/dma-fence.h +++ b/include/linux/dma-fence.h @@ -77,7 +77,7 @@ struct dma_fence { struct list_head cb_list; spinlock_t *lock; u64 context; - unsigned seqno; + u64 seqno; unsigned long flags; ktime_t timestamp; int error; @@ -244,7 +244,7 @@ struct dma_fence_ops { }; void dma_fence_init(struct dma_fence *fence, const struct dma_fence_ops *ops, - spinlock_t *lock, u64 context, unsigned seqno); + spinlock_t *lock, u64 context, u64 seqno); void dma_fence_release(struct kref *kref); void dma_fence_free(struct dma_fence *fence); @@ -414,9 +414,17 @@ dma_fence_is_signaled(struct dma_fence *fence) * Returns true if f1 is chronologically later than f2. Both fences must be * from the same context, since a seqno is not common across contexts. */ -static inline bool __dma_fence_is_later(u32 f1, u32 f2) +static inline bool __dma_fence_is_later(u64 f1, u64 f2) { - return (int)(f1 - f2) > 0; + /* This is for backward compatibility with drivers which can only handle + * 32bit sequence numbers. Use a 64bit compare when any of the higher + * bits are none zero, otherwise use a 32bit compare with wrap around + * handling. + */ + if (upper_32_bits(f1) || upper_32_bits(f2)) + return f1 > f2; + + return (int)(lower_32_bits(f1) - lower_32_bits(f2)) > 0; } /** @@ -548,21 +556,21 @@ u64 dma_fence_context_alloc(unsigned num); do { \ struct dma_fence *__ff = (f); \ if (IS_ENABLED(CONFIG_DMA_FENCE_TRACE)) \ - pr_info("f %llu#%u: " fmt, \ + pr_info("f %llu#%llu: " fmt, \ __ff->context, __ff->seqno, ##args); \ } while (0) #define DMA_FENCE_WARN(f, fmt, args...) \ do { \ struct dma_fence *__ff = (f); \ - pr_warn("f %llu#%u: " fmt, __ff->context, __ff->seqno, \ + pr_warn("f %llu#%llu: " fmt, __ff->context, __ff->seqno,\ ##args); \ } while (0) #define DMA_FENCE_ERR(f, fmt, args...) \ do { \ struct dma_fence *__ff = (f); \ - pr_err("f %llu#%u: " fmt, __ff->context, __ff->seqno, \ + pr_err("f %llu#%llu: " fmt, __ff->context, __ff->seqno, \ ##args); \ } while (0) -- cgit