From: David Stevens <[email protected]>
Allocate a new private stub fence in drm_syncobj_assign_null_handle,
instead of using a static stub fence.
When userspace creates a fence with DRM_SYNCOBJ_CREATE_SIGNALED or when
userspace signals a fence via DRM_IOCTL_SYNCOBJ_SIGNAL, the timestamp
obtained when the fence is exported and queried with SYNC_IOC_FILE_INFO
should match when the fence's status was changed from the perspective of
userspace, which is during the respective ioctl.
When a static stub fence started being used in by these ioctls, this
behavior changed. Instead, the timestamp returned by SYNC_IOC_FILE_INFO
became the first time anything used the static stub fence, which has no
meaning to userspace.
Signed-off-by: David Stevens <[email protected]>
---
v2 -> v3:
- reuse the static stub spinlock
v1 -> v2:
- checkpatch style fixes
drivers/dma-buf/dma-fence.c | 27 ++++++++++++++++++++++++++-
drivers/gpu/drm/drm_syncobj.c | 25 +++++++++++++++++++------
include/linux/dma-fence.h | 1 +
3 files changed, 46 insertions(+), 7 deletions(-)
diff --git a/drivers/dma-buf/dma-fence.c b/drivers/dma-buf/dma-fence.c
index d64fc03929be..ce0f5eff575d 100644
--- a/drivers/dma-buf/dma-fence.c
+++ b/drivers/dma-buf/dma-fence.c
@@ -123,7 +123,9 @@ static const struct dma_fence_ops dma_fence_stub_ops = {
/**
* dma_fence_get_stub - return a signaled fence
*
- * Return a stub fence which is already signaled.
+ * Return a stub fence which is already signaled. The fence's
+ * timestamp corresponds to the first time after boot this
+ * function is called.
*/
struct dma_fence *dma_fence_get_stub(void)
{
@@ -141,6 +143,29 @@ struct dma_fence *dma_fence_get_stub(void)
}
EXPORT_SYMBOL(dma_fence_get_stub);
+/**
+ * dma_fence_allocate_private_stub - return a private, signaled fence
+ *
+ * Return a newly allocated and signaled stub fence.
+ */
+struct dma_fence *dma_fence_allocate_private_stub(void)
+{
+ struct dma_fence *fence;
+
+ fence = kzalloc(sizeof(*fence), GFP_KERNEL);
+ if (fence == NULL)
+ return ERR_PTR(-ENOMEM);
+
+ dma_fence_init(fence,
+ &dma_fence_stub_ops,
+ &dma_fence_stub_lock,
+ 0, 0);
+ dma_fence_signal(fence);
+
+ return fence;
+}
+EXPORT_SYMBOL(dma_fence_allocate_private_stub);
+
/**
* dma_fence_context_alloc - allocate an array of fence contexts
* @num: amount of contexts to allocate
diff --git a/drivers/gpu/drm/drm_syncobj.c b/drivers/gpu/drm/drm_syncobj.c
index 349146049849..a54aa850d143 100644
--- a/drivers/gpu/drm/drm_syncobj.c
+++ b/drivers/gpu/drm/drm_syncobj.c
@@ -350,12 +350,16 @@ EXPORT_SYMBOL(drm_syncobj_replace_fence);
*
* Assign a already signaled stub fence to the sync object.
*/
-static void drm_syncobj_assign_null_handle(struct drm_syncobj *syncobj)
+static int drm_syncobj_assign_null_handle(struct drm_syncobj *syncobj)
{
- struct dma_fence *fence = dma_fence_get_stub();
+ struct dma_fence *fence = dma_fence_allocate_private_stub();
+
+ if (IS_ERR(fence))
+ return PTR_ERR(fence);
drm_syncobj_replace_fence(syncobj, fence);
dma_fence_put(fence);
+ return 0;
}
/* 5s default for wait submission */
@@ -469,6 +473,7 @@ EXPORT_SYMBOL(drm_syncobj_free);
int drm_syncobj_create(struct drm_syncobj **out_syncobj, uint32_t flags,
struct dma_fence *fence)
{
+ int ret;
struct drm_syncobj *syncobj;
syncobj = kzalloc(sizeof(struct drm_syncobj), GFP_KERNEL);
@@ -479,8 +484,13 @@ int drm_syncobj_create(struct drm_syncobj **out_syncobj, uint32_t flags,
INIT_LIST_HEAD(&syncobj->cb_list);
spin_lock_init(&syncobj->lock);
- if (flags & DRM_SYNCOBJ_CREATE_SIGNALED)
- drm_syncobj_assign_null_handle(syncobj);
+ if (flags & DRM_SYNCOBJ_CREATE_SIGNALED) {
+ ret = drm_syncobj_assign_null_handle(syncobj);
+ if (ret < 0) {
+ drm_syncobj_put(syncobj);
+ return ret;
+ }
+ }
if (fence)
drm_syncobj_replace_fence(syncobj, fence);
@@ -1322,8 +1332,11 @@ drm_syncobj_signal_ioctl(struct drm_device *dev, void *data,
if (ret < 0)
return ret;
- for (i = 0; i < args->count_handles; i++)
- drm_syncobj_assign_null_handle(syncobjs[i]);
+ for (i = 0; i < args->count_handles; i++) {
+ ret = drm_syncobj_assign_null_handle(syncobjs[i]);
+ if (ret < 0)
+ break;
+ }
drm_syncobj_array_free(syncobjs, args->count_handles);
diff --git a/include/linux/dma-fence.h b/include/linux/dma-fence.h
index 9f12efaaa93a..6ffb4b2c6371 100644
--- a/include/linux/dma-fence.h
+++ b/include/linux/dma-fence.h
@@ -587,6 +587,7 @@ static inline signed long dma_fence_wait(struct dma_fence *fence, bool intr)
}
struct dma_fence *dma_fence_get_stub(void);
+struct dma_fence *dma_fence_allocate_private_stub(void);
u64 dma_fence_context_alloc(unsigned num);
#define DMA_FENCE_TRACE(f, fmt, args...) \
--
2.31.0.208.g409f899ff0-goog
Am 08.04.21 um 11:54 schrieb David Stevens:
> From: David Stevens <[email protected]>
>
> Allocate a new private stub fence in drm_syncobj_assign_null_handle,
> instead of using a static stub fence.
>
> When userspace creates a fence with DRM_SYNCOBJ_CREATE_SIGNALED or when
> userspace signals a fence via DRM_IOCTL_SYNCOBJ_SIGNAL, the timestamp
> obtained when the fence is exported and queried with SYNC_IOC_FILE_INFO
> should match when the fence's status was changed from the perspective of
> userspace, which is during the respective ioctl.
>
> When a static stub fence started being used in by these ioctls, this
> behavior changed. Instead, the timestamp returned by SYNC_IOC_FILE_INFO
> became the first time anything used the static stub fence, which has no
> meaning to userspace.
>
> Signed-off-by: David Stevens <[email protected]>
Reviewed-by: Christian König <[email protected]>
Should I push this to drm-misc-next or how do you want to upstream it?
Thanks,
Christian.
> ---
> v2 -> v3:
> - reuse the static stub spinlock
> v1 -> v2:
> - checkpatch style fixes
>
> drivers/dma-buf/dma-fence.c | 27 ++++++++++++++++++++++++++-
> drivers/gpu/drm/drm_syncobj.c | 25 +++++++++++++++++++------
> include/linux/dma-fence.h | 1 +
> 3 files changed, 46 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/dma-buf/dma-fence.c b/drivers/dma-buf/dma-fence.c
> index d64fc03929be..ce0f5eff575d 100644
> --- a/drivers/dma-buf/dma-fence.c
> +++ b/drivers/dma-buf/dma-fence.c
> @@ -123,7 +123,9 @@ static const struct dma_fence_ops dma_fence_stub_ops = {
> /**
> * dma_fence_get_stub - return a signaled fence
> *
> - * Return a stub fence which is already signaled.
> + * Return a stub fence which is already signaled. The fence's
> + * timestamp corresponds to the first time after boot this
> + * function is called.
> */
> struct dma_fence *dma_fence_get_stub(void)
> {
> @@ -141,6 +143,29 @@ struct dma_fence *dma_fence_get_stub(void)
> }
> EXPORT_SYMBOL(dma_fence_get_stub);
>
> +/**
> + * dma_fence_allocate_private_stub - return a private, signaled fence
> + *
> + * Return a newly allocated and signaled stub fence.
> + */
> +struct dma_fence *dma_fence_allocate_private_stub(void)
> +{
> + struct dma_fence *fence;
> +
> + fence = kzalloc(sizeof(*fence), GFP_KERNEL);
> + if (fence == NULL)
> + return ERR_PTR(-ENOMEM);
> +
> + dma_fence_init(fence,
> + &dma_fence_stub_ops,
> + &dma_fence_stub_lock,
> + 0, 0);
> + dma_fence_signal(fence);
> +
> + return fence;
> +}
> +EXPORT_SYMBOL(dma_fence_allocate_private_stub);
> +
> /**
> * dma_fence_context_alloc - allocate an array of fence contexts
> * @num: amount of contexts to allocate
> diff --git a/drivers/gpu/drm/drm_syncobj.c b/drivers/gpu/drm/drm_syncobj.c
> index 349146049849..a54aa850d143 100644
> --- a/drivers/gpu/drm/drm_syncobj.c
> +++ b/drivers/gpu/drm/drm_syncobj.c
> @@ -350,12 +350,16 @@ EXPORT_SYMBOL(drm_syncobj_replace_fence);
> *
> * Assign a already signaled stub fence to the sync object.
> */
> -static void drm_syncobj_assign_null_handle(struct drm_syncobj *syncobj)
> +static int drm_syncobj_assign_null_handle(struct drm_syncobj *syncobj)
> {
> - struct dma_fence *fence = dma_fence_get_stub();
> + struct dma_fence *fence = dma_fence_allocate_private_stub();
> +
> + if (IS_ERR(fence))
> + return PTR_ERR(fence);
>
> drm_syncobj_replace_fence(syncobj, fence);
> dma_fence_put(fence);
> + return 0;
> }
>
> /* 5s default for wait submission */
> @@ -469,6 +473,7 @@ EXPORT_SYMBOL(drm_syncobj_free);
> int drm_syncobj_create(struct drm_syncobj **out_syncobj, uint32_t flags,
> struct dma_fence *fence)
> {
> + int ret;
> struct drm_syncobj *syncobj;
>
> syncobj = kzalloc(sizeof(struct drm_syncobj), GFP_KERNEL);
> @@ -479,8 +484,13 @@ int drm_syncobj_create(struct drm_syncobj **out_syncobj, uint32_t flags,
> INIT_LIST_HEAD(&syncobj->cb_list);
> spin_lock_init(&syncobj->lock);
>
> - if (flags & DRM_SYNCOBJ_CREATE_SIGNALED)
> - drm_syncobj_assign_null_handle(syncobj);
> + if (flags & DRM_SYNCOBJ_CREATE_SIGNALED) {
> + ret = drm_syncobj_assign_null_handle(syncobj);
> + if (ret < 0) {
> + drm_syncobj_put(syncobj);
> + return ret;
> + }
> + }
>
> if (fence)
> drm_syncobj_replace_fence(syncobj, fence);
> @@ -1322,8 +1332,11 @@ drm_syncobj_signal_ioctl(struct drm_device *dev, void *data,
> if (ret < 0)
> return ret;
>
> - for (i = 0; i < args->count_handles; i++)
> - drm_syncobj_assign_null_handle(syncobjs[i]);
> + for (i = 0; i < args->count_handles; i++) {
> + ret = drm_syncobj_assign_null_handle(syncobjs[i]);
> + if (ret < 0)
> + break;
> + }
>
> drm_syncobj_array_free(syncobjs, args->count_handles);
>
> diff --git a/include/linux/dma-fence.h b/include/linux/dma-fence.h
> index 9f12efaaa93a..6ffb4b2c6371 100644
> --- a/include/linux/dma-fence.h
> +++ b/include/linux/dma-fence.h
> @@ -587,6 +587,7 @@ static inline signed long dma_fence_wait(struct dma_fence *fence, bool intr)
> }
>
> struct dma_fence *dma_fence_get_stub(void);
> +struct dma_fence *dma_fence_allocate_private_stub(void);
> u64 dma_fence_context_alloc(unsigned num);
>
> #define DMA_FENCE_TRACE(f, fmt, args...) \
Pushing to drm-misc-next works for me. Thanks for the quick responses.
-David
On Thu, Apr 8, 2021 at 6:56 PM Christian König <[email protected]> wrote:
>
> Am 08.04.21 um 11:54 schrieb David Stevens:
> > From: David Stevens <[email protected]>
> >
> > Allocate a new private stub fence in drm_syncobj_assign_null_handle,
> > instead of using a static stub fence.
> >
> > When userspace creates a fence with DRM_SYNCOBJ_CREATE_SIGNALED or when
> > userspace signals a fence via DRM_IOCTL_SYNCOBJ_SIGNAL, the timestamp
> > obtained when the fence is exported and queried with SYNC_IOC_FILE_INFO
> > should match when the fence's status was changed from the perspective of
> > userspace, which is during the respective ioctl.
> >
> > When a static stub fence started being used in by these ioctls, this
> > behavior changed. Instead, the timestamp returned by SYNC_IOC_FILE_INFO
> > became the first time anything used the static stub fence, which has no
> > meaning to userspace.
> >
> > Signed-off-by: David Stevens <[email protected]>
>
> Reviewed-by: Christian König <[email protected]>
>
> Should I push this to drm-misc-next or how do you want to upstream it?
>
> Thanks,
> Christian.
>
> > ---
> > v2 -> v3:
> > - reuse the static stub spinlock
> > v1 -> v2:
> > - checkpatch style fixes
> >
> > drivers/dma-buf/dma-fence.c | 27 ++++++++++++++++++++++++++-
> > drivers/gpu/drm/drm_syncobj.c | 25 +++++++++++++++++++------
> > include/linux/dma-fence.h | 1 +
> > 3 files changed, 46 insertions(+), 7 deletions(-)
> >
> > diff --git a/drivers/dma-buf/dma-fence.c b/drivers/dma-buf/dma-fence.c
> > index d64fc03929be..ce0f5eff575d 100644
> > --- a/drivers/dma-buf/dma-fence.c
> > +++ b/drivers/dma-buf/dma-fence.c
> > @@ -123,7 +123,9 @@ static const struct dma_fence_ops dma_fence_stub_ops = {
> > /**
> > * dma_fence_get_stub - return a signaled fence
> > *
> > - * Return a stub fence which is already signaled.
> > + * Return a stub fence which is already signaled. The fence's
> > + * timestamp corresponds to the first time after boot this
> > + * function is called.
> > */
> > struct dma_fence *dma_fence_get_stub(void)
> > {
> > @@ -141,6 +143,29 @@ struct dma_fence *dma_fence_get_stub(void)
> > }
> > EXPORT_SYMBOL(dma_fence_get_stub);
> >
> > +/**
> > + * dma_fence_allocate_private_stub - return a private, signaled fence
> > + *
> > + * Return a newly allocated and signaled stub fence.
> > + */
> > +struct dma_fence *dma_fence_allocate_private_stub(void)
> > +{
> > + struct dma_fence *fence;
> > +
> > + fence = kzalloc(sizeof(*fence), GFP_KERNEL);
> > + if (fence == NULL)
> > + return ERR_PTR(-ENOMEM);
> > +
> > + dma_fence_init(fence,
> > + &dma_fence_stub_ops,
> > + &dma_fence_stub_lock,
> > + 0, 0);
> > + dma_fence_signal(fence);
> > +
> > + return fence;
> > +}
> > +EXPORT_SYMBOL(dma_fence_allocate_private_stub);
> > +
> > /**
> > * dma_fence_context_alloc - allocate an array of fence contexts
> > * @num: amount of contexts to allocate
> > diff --git a/drivers/gpu/drm/drm_syncobj.c b/drivers/gpu/drm/drm_syncobj.c
> > index 349146049849..a54aa850d143 100644
> > --- a/drivers/gpu/drm/drm_syncobj.c
> > +++ b/drivers/gpu/drm/drm_syncobj.c
> > @@ -350,12 +350,16 @@ EXPORT_SYMBOL(drm_syncobj_replace_fence);
> > *
> > * Assign a already signaled stub fence to the sync object.
> > */
> > -static void drm_syncobj_assign_null_handle(struct drm_syncobj *syncobj)
> > +static int drm_syncobj_assign_null_handle(struct drm_syncobj *syncobj)
> > {
> > - struct dma_fence *fence = dma_fence_get_stub();
> > + struct dma_fence *fence = dma_fence_allocate_private_stub();
> > +
> > + if (IS_ERR(fence))
> > + return PTR_ERR(fence);
> >
> > drm_syncobj_replace_fence(syncobj, fence);
> > dma_fence_put(fence);
> > + return 0;
> > }
> >
> > /* 5s default for wait submission */
> > @@ -469,6 +473,7 @@ EXPORT_SYMBOL(drm_syncobj_free);
> > int drm_syncobj_create(struct drm_syncobj **out_syncobj, uint32_t flags,
> > struct dma_fence *fence)
> > {
> > + int ret;
> > struct drm_syncobj *syncobj;
> >
> > syncobj = kzalloc(sizeof(struct drm_syncobj), GFP_KERNEL);
> > @@ -479,8 +484,13 @@ int drm_syncobj_create(struct drm_syncobj **out_syncobj, uint32_t flags,
> > INIT_LIST_HEAD(&syncobj->cb_list);
> > spin_lock_init(&syncobj->lock);
> >
> > - if (flags & DRM_SYNCOBJ_CREATE_SIGNALED)
> > - drm_syncobj_assign_null_handle(syncobj);
> > + if (flags & DRM_SYNCOBJ_CREATE_SIGNALED) {
> > + ret = drm_syncobj_assign_null_handle(syncobj);
> > + if (ret < 0) {
> > + drm_syncobj_put(syncobj);
> > + return ret;
> > + }
> > + }
> >
> > if (fence)
> > drm_syncobj_replace_fence(syncobj, fence);
> > @@ -1322,8 +1332,11 @@ drm_syncobj_signal_ioctl(struct drm_device *dev, void *data,
> > if (ret < 0)
> > return ret;
> >
> > - for (i = 0; i < args->count_handles; i++)
> > - drm_syncobj_assign_null_handle(syncobjs[i]);
> > + for (i = 0; i < args->count_handles; i++) {
> > + ret = drm_syncobj_assign_null_handle(syncobjs[i]);
> > + if (ret < 0)
> > + break;
> > + }
> >
> > drm_syncobj_array_free(syncobjs, args->count_handles);
> >
> > diff --git a/include/linux/dma-fence.h b/include/linux/dma-fence.h
> > index 9f12efaaa93a..6ffb4b2c6371 100644
> > --- a/include/linux/dma-fence.h
> > +++ b/include/linux/dma-fence.h
> > @@ -587,6 +587,7 @@ static inline signed long dma_fence_wait(struct dma_fence *fence, bool intr)
> > }
> >
> > struct dma_fence *dma_fence_get_stub(void);
> > +struct dma_fence *dma_fence_allocate_private_stub(void);
> > u64 dma_fence_context_alloc(unsigned num);
> >
> > #define DMA_FENCE_TRACE(f, fmt, args...) \
>