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-rw-r--r--drivers/dma-buf/Makefile2
-rw-r--r--drivers/dma-buf/dma-buf.c1
-rw-r--r--drivers/dma-buf/dma-fence.c13
-rw-r--r--drivers/dma-buf/dma-resv.c24
-rw-r--r--drivers/dma-buf/seqno-fence.c71
5 files changed, 25 insertions, 86 deletions
diff --git a/drivers/dma-buf/Makefile b/drivers/dma-buf/Makefile
index 40d81f23cacf..1ef021273a06 100644
--- a/drivers/dma-buf/Makefile
+++ b/drivers/dma-buf/Makefile
@@ -1,6 +1,6 @@
# SPDX-License-Identifier: GPL-2.0-only
obj-y := dma-buf.o dma-fence.o dma-fence-array.o dma-fence-chain.o \
- dma-resv.o seqno-fence.o
+ dma-resv.o
obj-$(CONFIG_DMABUF_HEAPS) += dma-heap.o
obj-$(CONFIG_DMABUF_HEAPS) += heaps/
obj-$(CONFIG_SYNC_FILE) += sync_file.o
diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c
index 63d32261b63f..474de2d988ca 100644
--- a/drivers/dma-buf/dma-buf.c
+++ b/drivers/dma-buf/dma-buf.c
@@ -82,6 +82,7 @@ static void dma_buf_release(struct dentry *dentry)
if (dmabuf->resv == (struct dma_resv *)&dmabuf[1])
dma_resv_fini(dmabuf->resv);
+ WARN_ON(!list_empty(&dmabuf->attachments));
module_put(dmabuf->owner);
kfree(dmabuf->name);
kfree(dmabuf);
diff --git a/drivers/dma-buf/dma-fence.c b/drivers/dma-buf/dma-fence.c
index ce0f5eff575d..1e82ecd443fa 100644
--- a/drivers/dma-buf/dma-fence.c
+++ b/drivers/dma-buf/dma-fence.c
@@ -616,20 +616,17 @@ EXPORT_SYMBOL(dma_fence_enable_sw_signaling);
* @cb: the callback to register
* @func: the function to call
*
+ * Add a software callback to the fence. The caller should keep a reference to
+ * the fence.
+ *
* @cb will be initialized by dma_fence_add_callback(), no initialization
* by the caller is required. Any number of callbacks can be registered
* to a fence, but a callback can only be registered to one fence at a time.
*
- * Note that the callback can be called from an atomic context. If
- * fence is already signaled, this function will return -ENOENT (and
+ * If fence is already signaled, this function will return -ENOENT (and
* *not* call the callback).
*
- * Add a software callback to the fence. Same restrictions apply to
- * refcount as it does to dma_fence_wait(), however the caller doesn't need to
- * keep a refcount to fence afterward dma_fence_add_callback() has returned:
- * when software access is enabled, the creator of the fence is required to keep
- * the fence alive until after it signals with dma_fence_signal(). The callback
- * itself can be called from irq context.
+ * Note that the callback can be called from an atomic context or irq context.
*
* Returns 0 in case of success, -ENOENT if the fence is already signaled
* and -EINVAL in case of error.
diff --git a/drivers/dma-buf/dma-resv.c b/drivers/dma-buf/dma-resv.c
index e744fd87c63c..84fbe60629e3 100644
--- a/drivers/dma-buf/dma-resv.c
+++ b/drivers/dma-buf/dma-resv.c
@@ -48,6 +48,8 @@
* write operations) or N shared fences (read operations). The RCU
* mechanism is used to protect read access to fences from locked
* write-side updates.
+ *
+ * See struct dma_resv for more details.
*/
DEFINE_WD_CLASS(reservation_ww_class);
@@ -137,7 +139,11 @@ EXPORT_SYMBOL(dma_resv_fini);
* @num_fences: number of fences we want to add
*
* Should be called before dma_resv_add_shared_fence(). Must
- * be called with obj->lock held.
+ * be called with @obj locked through dma_resv_lock().
+ *
+ * Note that the preallocated slots need to be re-reserved if @obj is unlocked
+ * at any time before calling dma_resv_add_shared_fence(). This is validated
+ * when CONFIG_DEBUG_MUTEXES is enabled.
*
* RETURNS
* Zero for success, or -errno
@@ -234,8 +240,10 @@ EXPORT_SYMBOL(dma_resv_reset_shared_max);
* @obj: the reservation object
* @fence: the shared fence to add
*
- * Add a fence to a shared slot, obj->lock must be held, and
+ * Add a fence to a shared slot, @obj must be locked with dma_resv_lock(), and
* dma_resv_reserve_shared() has been called.
+ *
+ * See also &dma_resv.fence for a discussion of the semantics.
*/
void dma_resv_add_shared_fence(struct dma_resv *obj, struct dma_fence *fence)
{
@@ -278,9 +286,11 @@ EXPORT_SYMBOL(dma_resv_add_shared_fence);
/**
* dma_resv_add_excl_fence - Add an exclusive fence.
* @obj: the reservation object
- * @fence: the shared fence to add
+ * @fence: the exclusive fence to add
*
- * Add a fence to the exclusive slot. The obj->lock must be held.
+ * Add a fence to the exclusive slot. @obj must be locked with dma_resv_lock().
+ * Note that this function replaces all fences attached to @obj, see also
+ * &dma_resv.fence_excl for a discussion of the semantics.
*/
void dma_resv_add_excl_fence(struct dma_resv *obj, struct dma_fence *fence)
{
@@ -609,9 +619,11 @@ static inline int dma_resv_test_signaled_single(struct dma_fence *passed_fence)
* fence
*
* Callers are not required to hold specific locks, but maybe hold
- * dma_resv_lock() already
+ * dma_resv_lock() already.
+ *
* RETURNS
- * true if all fences signaled, else false
+ *
+ * True if all fences signaled, else false.
*/
bool dma_resv_test_signaled(struct dma_resv *obj, bool test_all)
{
diff --git a/drivers/dma-buf/seqno-fence.c b/drivers/dma-buf/seqno-fence.c
deleted file mode 100644
index bfe14e94c488..000000000000
--- a/drivers/dma-buf/seqno-fence.c
+++ /dev/null
@@ -1,71 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-only
-/*
- * seqno-fence, using a dma-buf to synchronize fencing
- *
- * Copyright (C) 2012 Texas Instruments
- * Copyright (C) 2012-2014 Canonical Ltd
- * Authors:
- * Rob Clark <robdclark@gmail.com>
- * Maarten Lankhorst <maarten.lankhorst@canonical.com>
- */
-
-#include <linux/slab.h>
-#include <linux/export.h>
-#include <linux/seqno-fence.h>
-
-static const char *seqno_fence_get_driver_name(struct dma_fence *fence)
-{
- struct seqno_fence *seqno_fence = to_seqno_fence(fence);
-
- return seqno_fence->ops->get_driver_name(fence);
-}
-
-static const char *seqno_fence_get_timeline_name(struct dma_fence *fence)
-{
- struct seqno_fence *seqno_fence = to_seqno_fence(fence);
-
- return seqno_fence->ops->get_timeline_name(fence);
-}
-
-static bool seqno_enable_signaling(struct dma_fence *fence)
-{
- struct seqno_fence *seqno_fence = to_seqno_fence(fence);
-
- return seqno_fence->ops->enable_signaling(fence);
-}
-
-static bool seqno_signaled(struct dma_fence *fence)
-{
- struct seqno_fence *seqno_fence = to_seqno_fence(fence);
-
- return seqno_fence->ops->signaled && seqno_fence->ops->signaled(fence);
-}
-
-static void seqno_release(struct dma_fence *fence)
-{
- struct seqno_fence *f = to_seqno_fence(fence);
-
- dma_buf_put(f->sync_buf);
- if (f->ops->release)
- f->ops->release(fence);
- else
- dma_fence_free(&f->base);
-}
-
-static signed long seqno_wait(struct dma_fence *fence, bool intr,
- signed long timeout)
-{
- struct seqno_fence *f = to_seqno_fence(fence);
-
- return f->ops->wait(fence, intr, timeout);
-}
-
-const struct dma_fence_ops seqno_fence_ops = {
- .get_driver_name = seqno_fence_get_driver_name,
- .get_timeline_name = seqno_fence_get_timeline_name,
- .enable_signaling = seqno_enable_signaling,
- .signaled = seqno_signaled,
- .wait = seqno_wait,
- .release = seqno_release,
-};
-EXPORT_SYMBOL(seqno_fence_ops);