diff options
Diffstat (limited to 'drivers/dma-buf/dma-fence-chain.c')
| -rw-r--r-- | drivers/dma-buf/dma-fence-chain.c | 45 |
1 files changed, 38 insertions, 7 deletions
diff --git a/drivers/dma-buf/dma-fence-chain.c b/drivers/dma-buf/dma-fence-chain.c index b5089f64be2a..06f8ef97c6e8 100644 --- a/drivers/dma-buf/dma-fence-chain.c +++ b/drivers/dma-buf/dma-fence-chain.c @@ -62,7 +62,8 @@ struct dma_fence *dma_fence_chain_walk(struct dma_fence *fence) replacement = NULL; } - tmp = cmpxchg((void **)&chain->prev, (void *)prev, (void *)replacement); + tmp = cmpxchg((struct dma_fence __force **)&chain->prev, + prev, replacement); if (tmp == prev) dma_fence_put(tmp); else @@ -136,6 +137,7 @@ static void dma_fence_chain_cb(struct dma_fence *f, struct dma_fence_cb *cb) struct dma_fence_chain *chain; chain = container_of(cb, typeof(*chain), cb); + init_irq_work(&chain->work, dma_fence_chain_irq_work); irq_work_queue(&chain->work); dma_fence_put(f); } @@ -146,8 +148,7 @@ static bool dma_fence_chain_enable_signaling(struct dma_fence *fence) dma_fence_get(&head->base); dma_fence_chain_for_each(fence, &head->base) { - struct dma_fence_chain *chain = to_dma_fence_chain(fence); - struct dma_fence *f = chain ? chain->fence : fence; + struct dma_fence *f = dma_fence_chain_contained(fence); dma_fence_get(f); if (!dma_fence_add_callback(f, &head->cb, dma_fence_chain_cb)) { @@ -163,8 +164,7 @@ static bool dma_fence_chain_enable_signaling(struct dma_fence *fence) static bool dma_fence_chain_signaled(struct dma_fence *fence) { dma_fence_chain_for_each(fence, fence) { - struct dma_fence_chain *chain = to_dma_fence_chain(fence); - struct dma_fence *f = chain ? chain->fence : fence; + struct dma_fence *f = dma_fence_chain_contained(fence); if (!dma_fence_is_signaled(f)) { dma_fence_put(fence); @@ -178,8 +178,30 @@ static bool dma_fence_chain_signaled(struct dma_fence *fence) static void dma_fence_chain_release(struct dma_fence *fence) { struct dma_fence_chain *chain = to_dma_fence_chain(fence); + struct dma_fence *prev; + + /* Manually unlink the chain as much as possible to avoid recursion + * and potential stack overflow. + */ + while ((prev = rcu_dereference_protected(chain->prev, true))) { + struct dma_fence_chain *prev_chain; + + if (kref_read(&prev->refcount) > 1) + break; + + prev_chain = to_dma_fence_chain(prev); + if (!prev_chain) + break; + + /* No need for atomic operations since we hold the last + * reference to prev_chain. + */ + chain->prev = prev_chain->prev; + RCU_INIT_POINTER(prev_chain->prev, NULL); + dma_fence_put(prev); + } + dma_fence_put(prev); - dma_fence_put(rcu_dereference_protected(chain->prev, true)); dma_fence_put(chain->fence); dma_fence_free(fence); } @@ -199,6 +221,7 @@ EXPORT_SYMBOL(dma_fence_chain_ops); * @chain: the chain node to initialize * @prev: the previous fence * @fence: the current fence + * @seqno: the sequence number to use for the fence chain * * Initialize a new chain node and either start a new chain or add the node to * the existing chain of the previous fence. @@ -215,7 +238,6 @@ void dma_fence_chain_init(struct dma_fence_chain *chain, rcu_assign_pointer(chain->prev, prev); chain->fence = fence; chain->prev_seqno = 0; - init_irq_work(&chain->work, dma_fence_chain_irq_work); /* Try to reuse the context of the previous chain node. */ if (prev_chain && __dma_fence_is_later(seqno, prev->seqno, prev->ops)) { @@ -230,5 +252,14 @@ void dma_fence_chain_init(struct dma_fence_chain *chain, dma_fence_init(&chain->base, &dma_fence_chain_ops, &chain->lock, context, seqno); + + /* + * Chaining dma_fence_chain container together is only allowed through + * the prev fence and not through the contained fence. + * + * The correct way of handling this is to flatten out the fence + * structure into a dma_fence_array by the caller instead. + */ + WARN_ON(dma_fence_is_chain(fence)); } EXPORT_SYMBOL(dma_fence_chain_init); |