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-rw-r--r--drivers/dma-buf/dma-buf.c81
-rw-r--r--drivers/dma-buf/dma-resv.c69
2 files changed, 88 insertions, 62 deletions
diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c
index 2ea59cb8edcd..6437b2e978fb 100644
--- a/drivers/dma-buf/dma-buf.c
+++ b/drivers/dma-buf/dma-buf.c
@@ -67,12 +67,9 @@ static void dma_buf_release(struct dentry *dentry)
BUG_ON(dmabuf->vmapping_counter);
/*
- * Any fences that a dma-buf poll can wait on should be signaled
- * before releasing dma-buf. This is the responsibility of each
- * driver that uses the reservation objects.
- *
- * If you hit this BUG() it means someone dropped their ref to the
- * dma-buf while still having pending operation to the buffer.
+ * If you hit this BUG() it could mean:
+ * * There's a file reference imbalance in dma_buf_poll / dma_buf_poll_cb or somewhere else
+ * * dmabuf->cb_in/out.active are non-0 despite no pending fence callback
*/
BUG_ON(dmabuf->cb_in.active || dmabuf->cb_out.active);
@@ -200,6 +197,7 @@ static loff_t dma_buf_llseek(struct file *file, loff_t offset, int whence)
static void dma_buf_poll_cb(struct dma_fence *fence, struct dma_fence_cb *cb)
{
struct dma_buf_poll_cb_t *dcb = (struct dma_buf_poll_cb_t *)cb;
+ struct dma_buf *dmabuf = container_of(dcb->poll, struct dma_buf, poll);
unsigned long flags;
spin_lock_irqsave(&dcb->poll->lock, flags);
@@ -207,21 +205,18 @@ static void dma_buf_poll_cb(struct dma_fence *fence, struct dma_fence_cb *cb)
dcb->active = 0;
spin_unlock_irqrestore(&dcb->poll->lock, flags);
dma_fence_put(fence);
+ /* Paired with get_file in dma_buf_poll */
+ fput(dmabuf->file);
}
-static bool dma_buf_poll_shared(struct dma_resv *resv,
+static bool dma_buf_poll_add_cb(struct dma_resv *resv, bool write,
struct dma_buf_poll_cb_t *dcb)
{
- struct dma_resv_list *fobj = dma_resv_shared_list(resv);
+ struct dma_resv_iter cursor;
struct dma_fence *fence;
- int i, r;
-
- if (!fobj)
- return false;
+ int r;
- for (i = 0; i < fobj->shared_count; ++i) {
- fence = rcu_dereference_protected(fobj->shared[i],
- dma_resv_held(resv));
+ dma_resv_for_each_fence(&cursor, resv, write, fence) {
dma_fence_get(fence);
r = dma_fence_add_callback(fence, &dcb->cb, dma_buf_poll_cb);
if (!r)
@@ -232,24 +227,6 @@ static bool dma_buf_poll_shared(struct dma_resv *resv,
return false;
}
-static bool dma_buf_poll_excl(struct dma_resv *resv,
- struct dma_buf_poll_cb_t *dcb)
-{
- struct dma_fence *fence = dma_resv_excl_fence(resv);
- int r;
-
- if (!fence)
- return false;
-
- dma_fence_get(fence);
- r = dma_fence_add_callback(fence, &dcb->cb, dma_buf_poll_cb);
- if (!r)
- return true;
- dma_fence_put(fence);
-
- return false;
-}
-
static __poll_t dma_buf_poll(struct file *file, poll_table *poll)
{
struct dma_buf *dmabuf;
@@ -282,8 +259,10 @@ static __poll_t dma_buf_poll(struct file *file, poll_table *poll)
spin_unlock_irq(&dmabuf->poll.lock);
if (events & EPOLLOUT) {
- if (!dma_buf_poll_shared(resv, dcb) &&
- !dma_buf_poll_excl(resv, dcb))
+ /* Paired with fput in dma_buf_poll_cb */
+ get_file(dmabuf->file);
+
+ if (!dma_buf_poll_add_cb(resv, true, dcb))
/* No callback queued, wake up any other waiters */
dma_buf_poll_cb(NULL, &dcb->cb);
else
@@ -303,7 +282,10 @@ static __poll_t dma_buf_poll(struct file *file, poll_table *poll)
spin_unlock_irq(&dmabuf->poll.lock);
if (events & EPOLLIN) {
- if (!dma_buf_poll_excl(resv, dcb))
+ /* Paired with fput in dma_buf_poll_cb */
+ get_file(dmabuf->file);
+
+ if (!dma_buf_poll_add_cb(resv, false, dcb))
/* No callback queued, wake up any other waiters */
dma_buf_poll_cb(NULL, &dcb->cb);
else
@@ -1356,10 +1338,9 @@ static int dma_buf_debug_show(struct seq_file *s, void *unused)
{
struct dma_buf *buf_obj;
struct dma_buf_attachment *attach_obj;
- struct dma_resv *robj;
- struct dma_resv_list *fobj;
+ struct dma_resv_iter cursor;
struct dma_fence *fence;
- int count = 0, attach_count, shared_count, i;
+ int count = 0, attach_count;
size_t size = 0;
int ret;
@@ -1378,6 +1359,8 @@ static int dma_buf_debug_show(struct seq_file *s, void *unused)
if (ret)
goto error_unlock;
+
+ spin_lock(&buf_obj->name_lock);
seq_printf(s, "%08zu\t%08x\t%08x\t%08ld\t%s\t%08lu\t%s\n",
buf_obj->size,
buf_obj->file->f_flags, buf_obj->file->f_mode,
@@ -1385,22 +1368,12 @@ static int dma_buf_debug_show(struct seq_file *s, void *unused)
buf_obj->exp_name,
file_inode(buf_obj->file)->i_ino,
buf_obj->name ?: "");
+ spin_unlock(&buf_obj->name_lock);
- robj = buf_obj->resv;
- fence = dma_resv_excl_fence(robj);
- if (fence)
- seq_printf(s, "\tExclusive fence: %s %s %ssignalled\n",
- fence->ops->get_driver_name(fence),
- fence->ops->get_timeline_name(fence),
- dma_fence_is_signaled(fence) ? "" : "un");
-
- fobj = rcu_dereference_protected(robj->fence,
- dma_resv_held(robj));
- shared_count = fobj ? fobj->shared_count : 0;
- for (i = 0; i < shared_count; i++) {
- fence = rcu_dereference_protected(fobj->shared[i],
- dma_resv_held(robj));
- seq_printf(s, "\tShared fence: %s %s %ssignalled\n",
+ dma_resv_for_each_fence(&cursor, buf_obj->resv, true, fence) {
+ seq_printf(s, "\t%s fence: %s %s %ssignalled\n",
+ dma_resv_iter_is_exclusive(&cursor) ?
+ "Exclusive" : "Shared",
fence->ops->get_driver_name(fence),
fence->ops->get_timeline_name(fence),
dma_fence_is_signaled(fence) ? "" : "un");
diff --git a/drivers/dma-buf/dma-resv.c b/drivers/dma-buf/dma-resv.c
index a480af9581bd..9eb2baa387d4 100644
--- a/drivers/dma-buf/dma-resv.c
+++ b/drivers/dma-buf/dma-resv.c
@@ -333,10 +333,14 @@ static void dma_resv_iter_restart_unlocked(struct dma_resv_iter *cursor)
{
cursor->seq = read_seqcount_begin(&cursor->obj->seq);
cursor->index = -1;
- if (cursor->all_fences)
+ cursor->shared_count = 0;
+ if (cursor->all_fences) {
cursor->fences = dma_resv_shared_list(cursor->obj);
- else
+ if (cursor->fences)
+ cursor->shared_count = cursor->fences->shared_count;
+ } else {
cursor->fences = NULL;
+ }
cursor->is_restarted = true;
}
@@ -363,7 +367,7 @@ static void dma_resv_iter_walk_unlocked(struct dma_resv_iter *cursor)
continue;
} else if (!cursor->fences ||
- cursor->index >= cursor->fences->shared_count) {
+ cursor->index >= cursor->shared_count) {
cursor->fence = NULL;
break;
@@ -424,6 +428,57 @@ struct dma_fence *dma_resv_iter_next_unlocked(struct dma_resv_iter *cursor)
EXPORT_SYMBOL(dma_resv_iter_next_unlocked);
/**
+ * dma_resv_iter_first - first fence from a locked dma_resv object
+ * @cursor: cursor to record the current position
+ *
+ * Return the first fence in the dma_resv object while holding the
+ * &dma_resv.lock.
+ */
+struct dma_fence *dma_resv_iter_first(struct dma_resv_iter *cursor)
+{
+ struct dma_fence *fence;
+
+ dma_resv_assert_held(cursor->obj);
+
+ cursor->index = 0;
+ if (cursor->all_fences)
+ cursor->fences = dma_resv_shared_list(cursor->obj);
+ else
+ cursor->fences = NULL;
+
+ fence = dma_resv_excl_fence(cursor->obj);
+ if (!fence)
+ fence = dma_resv_iter_next(cursor);
+
+ cursor->is_restarted = true;
+ return fence;
+}
+EXPORT_SYMBOL_GPL(dma_resv_iter_first);
+
+/**
+ * dma_resv_iter_next - next fence from a locked dma_resv object
+ * @cursor: cursor to record the current position
+ *
+ * Return the next fences from the dma_resv object while holding the
+ * &dma_resv.lock.
+ */
+struct dma_fence *dma_resv_iter_next(struct dma_resv_iter *cursor)
+{
+ unsigned int idx;
+
+ dma_resv_assert_held(cursor->obj);
+
+ cursor->is_restarted = false;
+ if (!cursor->fences || cursor->index >= cursor->fences->shared_count)
+ return NULL;
+
+ idx = cursor->index++;
+ return rcu_dereference_protected(cursor->fences->shared[idx],
+ dma_resv_held(cursor->obj));
+}
+EXPORT_SYMBOL_GPL(dma_resv_iter_next);
+
+/**
* dma_resv_copy_fences - Copy all fences from src to dst.
* @dst: the destination reservation object
* @src: the source reservation object
@@ -448,10 +503,8 @@ int dma_resv_copy_fences(struct dma_resv *dst, struct dma_resv *src)
dma_resv_list_free(list);
dma_fence_put(excl);
- if (cursor.fences) {
- unsigned int cnt = cursor.fences->shared_count;
-
- list = dma_resv_list_alloc(cnt);
+ if (cursor.shared_count) {
+ list = dma_resv_list_alloc(cursor.shared_count);
if (!list) {
dma_resv_iter_end(&cursor);
return -ENOMEM;
@@ -522,7 +575,7 @@ int dma_resv_get_fences(struct dma_resv *obj, struct dma_fence **fence_excl,
if (fence_excl)
dma_fence_put(*fence_excl);
- count = cursor.fences ? cursor.fences->shared_count : 0;
+ count = cursor.shared_count;
count += fence_excl ? 0 : 1;
/* Eventually re-allocate the array */
generated by cgit (git 2.34.1) at 2024-05-23 17:32:01 +0000