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authorChristian König <christian.koenig@amd.com>2018-08-08 16:01:22 +0200
committerChristian König <christian.koenig@amd.com>2018-10-25 13:41:16 +0200
commit27836b641c1bf693c96c627388497b4e0f57441b (patch)
tree16eab48bbd71ffdbfd0b6e90fe9987313b61b80b /drivers/dma-buf
parent9d32bdbb5b5f8bcd5de241ec73208542b872136e (diff)
downloadlinux-27836b641c1bf693c96c627388497b4e0f57441b.tar.bz2
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/
Diffstat (limited to 'drivers/dma-buf')
-rw-r--r--drivers/dma-buf/reservation.c178
1 files changed, 58 insertions, 120 deletions
diff --git a/drivers/dma-buf/reservation.c b/drivers/dma-buf/reservation.c
index 6c95f61a32e7..5825fc336a13 100644
--- a/drivers/dma-buf/reservation.c
+++ b/drivers/dma-buf/reservation.c
@@ -68,105 +68,23 @@ EXPORT_SYMBOL(reservation_seqcount_string);
*/
int reservation_object_reserve_shared(struct reservation_object *obj)
{
- struct reservation_object_list *fobj, *old;
- u32 max;
+ struct reservation_object_list *old, *new;
+ unsigned int i, j, k, max;
old = reservation_object_get_list(obj);
if (old && old->shared_max) {
- if (old->shared_count < old->shared_max) {
- /* perform an in-place update */
- kfree(obj->staged);
- obj->staged = NULL;
+ if (old->shared_count < old->shared_max)
return 0;
- } else
+ else
max = old->shared_max * 2;
- } else
- max = 4;
-
- /*
- * resize obj->staged or allocate if it doesn't exist,
- * noop if already correct size
- */
- fobj = krealloc(obj->staged, offsetof(typeof(*fobj), shared[max]),
- GFP_KERNEL);
- if (!fobj)
- return -ENOMEM;
-
- obj->staged = fobj;
- fobj->shared_max = max;
- return 0;
-}
-EXPORT_SYMBOL(reservation_object_reserve_shared);
-
-static void
-reservation_object_add_shared_inplace(struct reservation_object *obj,
- struct reservation_object_list *fobj,
- struct dma_fence *fence)
-{
- struct dma_fence *signaled = NULL;
- u32 i, signaled_idx;
-
- dma_fence_get(fence);
-
- preempt_disable();
- write_seqcount_begin(&obj->seq);
-
- for (i = 0; i < fobj->shared_count; ++i) {
- struct dma_fence *old_fence;
-
- old_fence = rcu_dereference_protected(fobj->shared[i],
- reservation_object_held(obj));
-
- if (old_fence->context == fence->context) {
- /* memory barrier is added by write_seqcount_begin */
- RCU_INIT_POINTER(fobj->shared[i], fence);
- write_seqcount_end(&obj->seq);
- preempt_enable();
-
- dma_fence_put(old_fence);
- return;
- }
-
- if (!signaled && dma_fence_is_signaled(old_fence)) {
- signaled = old_fence;
- signaled_idx = i;
- }
- }
-
- /*
- * memory barrier is added by write_seqcount_begin,
- * fobj->shared_count is protected by this lock too
- */
- if (signaled) {
- RCU_INIT_POINTER(fobj->shared[signaled_idx], fence);
} else {
- BUG_ON(fobj->shared_count >= fobj->shared_max);
- RCU_INIT_POINTER(fobj->shared[fobj->shared_count], fence);
- fobj->shared_count++;
+ max = 4;
}
- write_seqcount_end(&obj->seq);
- preempt_enable();
-
- dma_fence_put(signaled);
-}
-
-static void
-reservation_object_add_shared_replace(struct reservation_object *obj,
- struct reservation_object_list *old,
- struct reservation_object_list *fobj,
- struct dma_fence *fence)
-{
- unsigned i, j, k;
-
- dma_fence_get(fence);
-
- if (!old) {
- RCU_INIT_POINTER(fobj->shared[0], fence);
- fobj->shared_count = 1;
- goto done;
- }
+ new = kmalloc(offsetof(typeof(*new), shared[max]), GFP_KERNEL);
+ if (!new)
+ return -ENOMEM;
/*
* no need to bump fence refcounts, rcu_read access
@@ -174,46 +92,45 @@ reservation_object_add_shared_replace(struct reservation_object *obj,
* references from the old struct are carried over to
* the new.
*/
- for (i = 0, j = 0, k = fobj->shared_max; i < old->shared_count; ++i) {
- struct dma_fence *check;
+ for (i = 0, j = 0, k = max; i < (old ? old->shared_count : 0); ++i) {
+ struct dma_fence *fence;
- check = rcu_dereference_protected(old->shared[i],
- reservation_object_held(obj));
-
- if (check->context == fence->context ||
- dma_fence_is_signaled(check))
- RCU_INIT_POINTER(fobj->shared[--k], check);
+ fence = rcu_dereference_protected(old->shared[i],
+ reservation_object_held(obj));
+ if (dma_fence_is_signaled(fence))
+ RCU_INIT_POINTER(new->shared[--k], fence);
else
- RCU_INIT_POINTER(fobj->shared[j++], check);
+ RCU_INIT_POINTER(new->shared[j++], fence);
}
- fobj->shared_count = j;
- RCU_INIT_POINTER(fobj->shared[fobj->shared_count], fence);
- fobj->shared_count++;
+ new->shared_count = j;
+ new->shared_max = max;
-done:
preempt_disable();
write_seqcount_begin(&obj->seq);
/*
* RCU_INIT_POINTER can be used here,
* seqcount provides the necessary barriers
*/
- RCU_INIT_POINTER(obj->fence, fobj);
+ RCU_INIT_POINTER(obj->fence, new);
write_seqcount_end(&obj->seq);
preempt_enable();
if (!old)
- return;
+ return 0;
/* Drop the references to the signaled fences */
- for (i = k; i < fobj->shared_max; ++i) {
- struct dma_fence *f;
+ for (i = k; i < new->shared_max; ++i) {
+ struct dma_fence *fence;
- f = rcu_dereference_protected(fobj->shared[i],
- reservation_object_held(obj));
- dma_fence_put(f);
+ fence = rcu_dereference_protected(new->shared[i],
+ reservation_object_held(obj));
+ dma_fence_put(fence);
}
kfree_rcu(old, rcu);
+
+ return 0;
}
+EXPORT_SYMBOL(reservation_object_reserve_shared);
/**
* reservation_object_add_shared_fence - Add a fence to a shared slot
@@ -226,15 +143,39 @@ done:
void reservation_object_add_shared_fence(struct reservation_object *obj,
struct dma_fence *fence)
{
- struct reservation_object_list *old, *fobj = obj->staged;
+ struct reservation_object_list *fobj;
+ unsigned int i;
- old = reservation_object_get_list(obj);
- obj->staged = NULL;
+ dma_fence_get(fence);
+
+ fobj = reservation_object_get_list(obj);
- if (!fobj)
- reservation_object_add_shared_inplace(obj, old, fence);
- else
- reservation_object_add_shared_replace(obj, old, fobj, fence);
+ preempt_disable();
+ write_seqcount_begin(&obj->seq);
+
+ for (i = 0; i < fobj->shared_count; ++i) {
+ struct dma_fence *old_fence;
+
+ old_fence = rcu_dereference_protected(fobj->shared[i],
+ reservation_object_held(obj));
+ if (old_fence->context == fence->context ||
+ dma_fence_is_signaled(old_fence)) {
+ dma_fence_put(old_fence);
+ goto replace;
+ }
+ }
+
+ BUG_ON(fobj->shared_count >= fobj->shared_max);
+ fobj->shared_count++;
+
+replace:
+ /*
+ * memory barrier is added by write_seqcount_begin,
+ * fobj->shared_count is protected by this lock too
+ */
+ RCU_INIT_POINTER(fobj->shared[i], fence);
+ write_seqcount_end(&obj->seq);
+ preempt_enable();
}
EXPORT_SYMBOL(reservation_object_add_shared_fence);
@@ -343,9 +284,6 @@ retry:
new = dma_fence_get_rcu_safe(&src->fence_excl);
rcu_read_unlock();
- kfree(dst->staged);
- dst->staged = NULL;
-
src_list = reservation_object_get_list(dst);
old = reservation_object_get_excl(dst);