EXPORT_SYMBOL(reservation_seqcount_string);
/**
- * reservation_object_reserve_shared - Reserve space to add a shared
- * fence to a reservation_object.
+ * reservation_object_reserve_shared - Reserve space to add shared fences to
+ * a reservation_object.
* @obj: reservation object
+ * @num_fences: number of fences we want to add
*
* Should be called before reservation_object_add_shared_fence(). Must
* be called with obj->lock held.
* RETURNS
* Zero for success, or -errno
*/
-int reservation_object_reserve_shared(struct reservation_object *obj)
+int reservation_object_reserve_shared(struct reservation_object *obj,
+ unsigned int num_fences)
{
- struct reservation_object_list *fobj, *old;
- u32 max;
+ struct reservation_object_list *old, *new;
+ unsigned int i, j, k, max;
+
+ reservation_object_assert_held(obj);
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 + num_fences) <= old->shared_max)
return 0;
- } 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
+ max = max(old->shared_count + num_fences,
+ old->shared_max * 2);
} 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
* 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
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, count;
- old = reservation_object_get_list(obj);
- obj->staged = NULL;
+ dma_fence_get(fence);
+
+ reservation_object_assert_held(obj);
+
+ fobj = reservation_object_get_list(obj);
+ count = fobj->shared_count;
- 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 < 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);
+ count++;
+
+replace:
+ RCU_INIT_POINTER(fobj->shared[i], fence);
+ /* pointer update must be visible before we extend the shared_count */
+ smp_store_mb(fobj->shared_count, count);
+
+ write_seqcount_end(&obj->seq);
+ preempt_enable();
}
EXPORT_SYMBOL(reservation_object_add_shared_fence);
struct reservation_object_list *old;
u32 i = 0;
+ reservation_object_assert_held(obj);
+
old = reservation_object_get_list(obj);
if (old)
i = old->shared_count;
size_t size;
unsigned i;
+ reservation_object_assert_held(dst);
+
rcu_read_lock();
src_list = rcu_dereference(src->fence);
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);
projects / linux-2.6-microblaze.git / blobdiff