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https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-25 10:19:47 +00:00
dma-buf: remove shared fence staging in reservation object
No need for that any more. Just replace the list when there isn't enough room any more for the additional fence. Signed-off-by: Christian König <christian.koenig@amd.com> Reviewed-by: Junwei Zhang <Jerry.Zhang@amd.com> Reviewed-by: Huang Rui <ray.huang@amd.com> Link: https://patchwork.kernel.org/patch/10626143/
This commit is contained in:
Christian König
parent
9d32bdbb5b
commit
27836b641c
2 changed files with 58 additions and 124 deletions
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@ -68,105 +68,23 @@ EXPORT_SYMBOL(reservation_seqcount_string);
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*/
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int reservation_object_reserve_shared(struct reservation_object *obj)
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{
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struct reservation_object_list *fobj, *old;
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u32 max;
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struct reservation_object_list *old, *new;
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unsigned int i, j, k, max;
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old = reservation_object_get_list(obj);
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if (old && old->shared_max) {
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if (old->shared_count < old->shared_max) {
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/* perform an in-place update */
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kfree(obj->staged);
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obj->staged = NULL;
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if (old->shared_count < old->shared_max)
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return 0;
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} else
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else
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max = old->shared_max * 2;
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} else
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max = 4;
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/*
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* resize obj->staged or allocate if it doesn't exist,
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* noop if already correct size
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*/
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fobj = krealloc(obj->staged, offsetof(typeof(*fobj), shared[max]),
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GFP_KERNEL);
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if (!fobj)
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return -ENOMEM;
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obj->staged = fobj;
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fobj->shared_max = max;
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return 0;
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}
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EXPORT_SYMBOL(reservation_object_reserve_shared);
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static void
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reservation_object_add_shared_inplace(struct reservation_object *obj,
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struct reservation_object_list *fobj,
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struct dma_fence *fence)
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{
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struct dma_fence *signaled = NULL;
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u32 i, signaled_idx;
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dma_fence_get(fence);
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preempt_disable();
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write_seqcount_begin(&obj->seq);
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for (i = 0; i < fobj->shared_count; ++i) {
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struct dma_fence *old_fence;
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old_fence = rcu_dereference_protected(fobj->shared[i],
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reservation_object_held(obj));
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if (old_fence->context == fence->context) {
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/* memory barrier is added by write_seqcount_begin */
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RCU_INIT_POINTER(fobj->shared[i], fence);
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write_seqcount_end(&obj->seq);
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preempt_enable();
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dma_fence_put(old_fence);
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return;
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}
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if (!signaled && dma_fence_is_signaled(old_fence)) {
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signaled = old_fence;
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signaled_idx = i;
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}
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}
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/*
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* memory barrier is added by write_seqcount_begin,
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* fobj->shared_count is protected by this lock too
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*/
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if (signaled) {
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RCU_INIT_POINTER(fobj->shared[signaled_idx], fence);
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} else {
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BUG_ON(fobj->shared_count >= fobj->shared_max);
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RCU_INIT_POINTER(fobj->shared[fobj->shared_count], fence);
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fobj->shared_count++;
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max = 4;
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}
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write_seqcount_end(&obj->seq);
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preempt_enable();
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dma_fence_put(signaled);
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}
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static void
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reservation_object_add_shared_replace(struct reservation_object *obj,
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struct reservation_object_list *old,
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struct reservation_object_list *fobj,
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struct dma_fence *fence)
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{
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unsigned i, j, k;
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dma_fence_get(fence);
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if (!old) {
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RCU_INIT_POINTER(fobj->shared[0], fence);
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fobj->shared_count = 1;
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goto done;
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}
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new = kmalloc(offsetof(typeof(*new), shared[max]), GFP_KERNEL);
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if (!new)
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return -ENOMEM;
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/*
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* no need to bump fence refcounts, rcu_read access
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@ -174,46 +92,45 @@ reservation_object_add_shared_replace(struct reservation_object *obj,
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* references from the old struct are carried over to
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* the new.
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*/
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for (i = 0, j = 0, k = fobj->shared_max; i < old->shared_count; ++i) {
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struct dma_fence *check;
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for (i = 0, j = 0, k = max; i < (old ? old->shared_count : 0); ++i) {
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struct dma_fence *fence;
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check = rcu_dereference_protected(old->shared[i],
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reservation_object_held(obj));
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if (check->context == fence->context ||
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dma_fence_is_signaled(check))
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RCU_INIT_POINTER(fobj->shared[--k], check);
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fence = rcu_dereference_protected(old->shared[i],
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reservation_object_held(obj));
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if (dma_fence_is_signaled(fence))
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RCU_INIT_POINTER(new->shared[--k], fence);
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else
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RCU_INIT_POINTER(fobj->shared[j++], check);
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RCU_INIT_POINTER(new->shared[j++], fence);
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}
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fobj->shared_count = j;
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RCU_INIT_POINTER(fobj->shared[fobj->shared_count], fence);
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fobj->shared_count++;
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new->shared_count = j;
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new->shared_max = max;
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done:
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preempt_disable();
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write_seqcount_begin(&obj->seq);
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/*
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* RCU_INIT_POINTER can be used here,
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* seqcount provides the necessary barriers
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*/
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RCU_INIT_POINTER(obj->fence, fobj);
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RCU_INIT_POINTER(obj->fence, new);
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write_seqcount_end(&obj->seq);
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preempt_enable();
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if (!old)
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return;
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return 0;
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/* Drop the references to the signaled fences */
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for (i = k; i < fobj->shared_max; ++i) {
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struct dma_fence *f;
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for (i = k; i < new->shared_max; ++i) {
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struct dma_fence *fence;
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f = rcu_dereference_protected(fobj->shared[i],
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reservation_object_held(obj));
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dma_fence_put(f);
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fence = rcu_dereference_protected(new->shared[i],
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reservation_object_held(obj));
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dma_fence_put(fence);
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}
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kfree_rcu(old, rcu);
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return 0;
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}
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EXPORT_SYMBOL(reservation_object_reserve_shared);
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/**
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* reservation_object_add_shared_fence - Add a fence to a shared slot
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@ -226,15 +143,39 @@ reservation_object_add_shared_replace(struct reservation_object *obj,
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void reservation_object_add_shared_fence(struct reservation_object *obj,
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struct dma_fence *fence)
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{
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struct reservation_object_list *old, *fobj = obj->staged;
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struct reservation_object_list *fobj;
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unsigned int i;
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old = reservation_object_get_list(obj);
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obj->staged = NULL;
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dma_fence_get(fence);
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if (!fobj)
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reservation_object_add_shared_inplace(obj, old, fence);
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else
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reservation_object_add_shared_replace(obj, old, fobj, fence);
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fobj = reservation_object_get_list(obj);
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preempt_disable();
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write_seqcount_begin(&obj->seq);
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for (i = 0; i < fobj->shared_count; ++i) {
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struct dma_fence *old_fence;
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old_fence = rcu_dereference_protected(fobj->shared[i],
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reservation_object_held(obj));
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if (old_fence->context == fence->context ||
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dma_fence_is_signaled(old_fence)) {
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dma_fence_put(old_fence);
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goto replace;
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}
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}
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BUG_ON(fobj->shared_count >= fobj->shared_max);
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fobj->shared_count++;
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replace:
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/*
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* memory barrier is added by write_seqcount_begin,
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* fobj->shared_count is protected by this lock too
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*/
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RCU_INIT_POINTER(fobj->shared[i], fence);
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write_seqcount_end(&obj->seq);
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preempt_enable();
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}
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EXPORT_SYMBOL(reservation_object_add_shared_fence);
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@ -343,9 +284,6 @@ int reservation_object_copy_fences(struct reservation_object *dst,
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new = dma_fence_get_rcu_safe(&src->fence_excl);
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rcu_read_unlock();
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kfree(dst->staged);
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dst->staged = NULL;
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src_list = reservation_object_get_list(dst);
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old = reservation_object_get_excl(dst);
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@ -68,7 +68,6 @@ struct reservation_object_list {
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* @seq: sequence count for managing RCU read-side synchronization
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* @fence_excl: the exclusive fence, if there is one currently
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* @fence: list of current shared fences
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* @staged: staged copy of shared fences for RCU updates
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*/
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struct reservation_object {
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struct ww_mutex lock;
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@ -76,7 +75,6 @@ struct reservation_object {
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struct dma_fence __rcu *fence_excl;
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struct reservation_object_list __rcu *fence;
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struct reservation_object_list *staged;
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};
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#define reservation_object_held(obj) lockdep_is_held(&(obj)->lock.base)
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@ -95,7 +93,6 @@ reservation_object_init(struct reservation_object *obj)
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__seqcount_init(&obj->seq, reservation_seqcount_string, &reservation_seqcount_class);
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RCU_INIT_POINTER(obj->fence, NULL);
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RCU_INIT_POINTER(obj->fence_excl, NULL);
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obj->staged = NULL;
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}
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/**
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@ -124,7 +121,6 @@ reservation_object_fini(struct reservation_object *obj)
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kfree(fobj);
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}
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kfree(obj->staged);
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ww_mutex_destroy(&obj->lock);
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}
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