From 67c97fb79a7f8621d4514275691d75f5ff158c46 Mon Sep 17 00:00:00 2001 From: Christian König Date: Tue, 6 Aug 2019 14:19:33 +0200 Subject: dma-buf: add reservation_object_fences helper MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Add a new helper to get a consistent set of pointers from the reservation object. While at it group all access helpers together in the header file. v2: correctly return shared_count as well Signed-off-by: Christian König Reviewed-by: Chris Wilson Link: https://patchwork.freedesktop.org/patch/322378/?series=64837&rev=1 --- drivers/dma-buf/dma-buf.c | 31 +++------------- drivers/dma-buf/reservation.c | 82 ++++++++++++++----------------------------- 2 files changed, 31 insertions(+), 82 deletions(-) (limited to 'drivers/dma-buf') diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c index f45bfb29ef96..67510f2be8bc 100644 --- a/drivers/dma-buf/dma-buf.c +++ b/drivers/dma-buf/dma-buf.c @@ -199,7 +199,7 @@ static __poll_t dma_buf_poll(struct file *file, poll_table *poll) struct reservation_object_list *fobj; struct dma_fence *fence_excl; __poll_t events; - unsigned shared_count, seq; + unsigned shared_count; dmabuf = file->private_data; if (!dmabuf || !dmabuf->resv) @@ -213,21 +213,8 @@ static __poll_t dma_buf_poll(struct file *file, poll_table *poll) if (!events) return 0; -retry: - seq = read_seqcount_begin(&resv->seq); rcu_read_lock(); - - fobj = rcu_dereference(resv->fence); - if (fobj) - shared_count = fobj->shared_count; - else - shared_count = 0; - fence_excl = rcu_dereference(resv->fence_excl); - if (read_seqcount_retry(&resv->seq, seq)) { - rcu_read_unlock(); - goto retry; - } - + reservation_object_fences(resv, &fence_excl, &fobj, &shared_count); if (fence_excl && (!(events & EPOLLOUT) || shared_count == 0)) { struct dma_buf_poll_cb_t *dcb = &dmabuf->cb_excl; __poll_t pevents = EPOLLIN; @@ -1157,7 +1144,6 @@ static int dma_buf_debug_show(struct seq_file *s, void *unused) struct reservation_object *robj; struct reservation_object_list *fobj; struct dma_fence *fence; - unsigned seq; int count = 0, attach_count, shared_count, i; size_t size = 0; @@ -1188,16 +1174,9 @@ static int dma_buf_debug_show(struct seq_file *s, void *unused) buf_obj->name ?: ""); robj = buf_obj->resv; - while (true) { - seq = read_seqcount_begin(&robj->seq); - rcu_read_lock(); - fobj = rcu_dereference(robj->fence); - shared_count = fobj ? fobj->shared_count : 0; - fence = rcu_dereference(robj->fence_excl); - if (!read_seqcount_retry(&robj->seq, seq)) - break; - rcu_read_unlock(); - } + rcu_read_lock(); + reservation_object_fences(robj, &fence, &fobj, &shared_count); + rcu_read_unlock(); if (fence) seq_printf(s, "\tExclusive fence: %s %s %ssignalled\n", diff --git a/drivers/dma-buf/reservation.c b/drivers/dma-buf/reservation.c index ad6775b32a73..8fcaddffd5d4 100644 --- a/drivers/dma-buf/reservation.c +++ b/drivers/dma-buf/reservation.c @@ -317,17 +317,15 @@ int reservation_object_copy_fences(struct reservation_object *dst, { struct reservation_object_list *src_list, *dst_list; struct dma_fence *old, *new; - unsigned i; + unsigned int i, shared_count; reservation_object_assert_held(dst); rcu_read_lock(); - src_list = rcu_dereference(src->fence); retry: - if (src_list) { - unsigned shared_count = src_list->shared_count; - + reservation_object_fences(src, &new, &src_list, &shared_count); + if (shared_count) { rcu_read_unlock(); dst_list = reservation_object_list_alloc(shared_count); @@ -335,14 +333,14 @@ retry: return -ENOMEM; rcu_read_lock(); - src_list = rcu_dereference(src->fence); - if (!src_list || src_list->shared_count > shared_count) { + reservation_object_fences(src, &new, &src_list, &shared_count); + if (!src_list || shared_count > dst_list->shared_max) { kfree(dst_list); goto retry; } dst_list->shared_count = 0; - for (i = 0; i < src_list->shared_count; ++i) { + for (i = 0; i < shared_count; ++i) { struct dma_fence *fence; fence = rcu_dereference(src_list->shared[i]); @@ -352,7 +350,6 @@ retry: if (!dma_fence_get_rcu(fence)) { reservation_object_list_free(dst_list); - src_list = rcu_dereference(src->fence); goto retry; } @@ -367,7 +364,10 @@ retry: dst_list = NULL; } - new = dma_fence_get_rcu_safe(&src->fence_excl); + if (new && !dma_fence_get_rcu(new)) { + reservation_object_list_free(dst_list); + goto retry; + } rcu_read_unlock(); src_list = reservation_object_get_list(dst); @@ -413,19 +413,18 @@ int reservation_object_get_fences_rcu(struct reservation_object *obj, do { struct reservation_object_list *fobj; - unsigned int i, seq; + unsigned int i; size_t sz = 0; - shared_count = i = 0; + i = 0; rcu_read_lock(); - seq = read_seqcount_begin(&obj->seq); + reservation_object_fences(obj, &fence_excl, &fobj, + &shared_count); - fence_excl = rcu_dereference(obj->fence_excl); if (fence_excl && !dma_fence_get_rcu(fence_excl)) goto unlock; - fobj = rcu_dereference(obj->fence); if (fobj) sz += sizeof(*shared) * fobj->shared_max; @@ -453,7 +452,6 @@ int reservation_object_get_fences_rcu(struct reservation_object *obj, break; } shared = nshared; - shared_count = fobj ? fobj->shared_count : 0; for (i = 0; i < shared_count; ++i) { shared[i] = rcu_dereference(fobj->shared[i]); if (!dma_fence_get_rcu(shared[i])) @@ -461,7 +459,7 @@ int reservation_object_get_fences_rcu(struct reservation_object *obj, } } - if (i != shared_count || read_seqcount_retry(&obj->seq, seq)) { + if (i != shared_count) { while (i--) dma_fence_put(shared[i]); dma_fence_put(fence_excl); @@ -505,18 +503,17 @@ long reservation_object_wait_timeout_rcu(struct reservation_object *obj, bool wait_all, bool intr, unsigned long timeout) { + struct reservation_object_list *fobj; struct dma_fence *fence; - unsigned seq, shared_count; + unsigned shared_count; long ret = timeout ? timeout : 1; int i; retry: - shared_count = 0; - seq = read_seqcount_begin(&obj->seq); rcu_read_lock(); i = -1; - fence = rcu_dereference(obj->fence_excl); + reservation_object_fences(obj, &fence, &fobj, &shared_count); if (fence && !test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags)) { if (!dma_fence_get_rcu(fence)) goto unlock_retry; @@ -531,12 +528,6 @@ retry: } if (wait_all) { - struct reservation_object_list *fobj = - rcu_dereference(obj->fence); - - if (fobj) - shared_count = fobj->shared_count; - for (i = 0; !fence && i < shared_count; ++i) { struct dma_fence *lfence = rcu_dereference(fobj->shared[i]); @@ -559,11 +550,6 @@ retry: rcu_read_unlock(); if (fence) { - if (read_seqcount_retry(&obj->seq, seq)) { - dma_fence_put(fence); - goto retry; - } - ret = dma_fence_wait_timeout(fence, intr, ret); dma_fence_put(fence); if (ret > 0 && wait_all && (i + 1 < shared_count)) @@ -608,24 +594,19 @@ reservation_object_test_signaled_single(struct dma_fence *passed_fence) bool reservation_object_test_signaled_rcu(struct reservation_object *obj, bool test_all) { - unsigned seq, shared_count; + struct reservation_object_list *fobj; + struct dma_fence *fence_excl; + unsigned shared_count; int ret; rcu_read_lock(); retry: ret = true; - shared_count = 0; - seq = read_seqcount_begin(&obj->seq); + reservation_object_fences(obj, &fence_excl, &fobj, &shared_count); if (test_all) { unsigned i; - struct reservation_object_list *fobj = - rcu_dereference(obj->fence); - - if (fobj) - shared_count = fobj->shared_count; - for (i = 0; i < shared_count; ++i) { struct dma_fence *fence = rcu_dereference(fobj->shared[i]); @@ -635,23 +616,12 @@ retry: else if (!ret) break; } - - if (read_seqcount_retry(&obj->seq, seq)) - goto retry; } - if (!shared_count) { - struct dma_fence *fence_excl = rcu_dereference(obj->fence_excl); - - if (fence_excl) { - ret = reservation_object_test_signaled_single( - fence_excl); - if (ret < 0) - goto retry; - - if (read_seqcount_retry(&obj->seq, seq)) - goto retry; - } + if (!shared_count && fence_excl) { + ret = reservation_object_test_signaled_single(fence_excl); + if (ret < 0) + goto retry; } rcu_read_unlock(); -- cgit v1.2.3