Re: [Intel-gfx] [PATCH 2/2] drm/i915: Prevent concurrent tiling/framebuffer modifications
On Wed, Mar 01, 2017 at 03:09:36PM +0200, Ville Syrjälä wrote:
> On Tue, Feb 28, 2017 at 04:22:33PM +, Chris Wilson wrote:
> > Reintroduce a lock around tiling vs framebuffer creation to prevent
> > modification of the obj->tiling_and_stride whilst the framebuffer is
> > being created. Rather than use struct_mutex once again, use the
> > per-object lock - this will also be required in future to prevent
> > changing the tiling whilst submitting rendering.
> >
> > Fixes: 24dbf51a5517 ("drm/i915: struct_mutex is not required for allocating
> > the framebuffer")
> > Signed-off-by: Chris Wilson
> > Cc: Ville Syrjälä
> > ---
> > drivers/gpu/drm/i915/i915_gem_object.h | 18 +-
> > drivers/gpu/drm/i915/i915_gem_shrinker.c | 2 +-
> > drivers/gpu/drm/i915/i915_gem_tiling.c | 9 -
> > drivers/gpu/drm/i915/intel_display.c | 25 -
> > 4 files changed, 42 insertions(+), 12 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/i915_gem_object.h
> > b/drivers/gpu/drm/i915/i915_gem_object.h
> > index ad1bc0b1a0c2..8c02c8ec2a3b 100644
> > --- a/drivers/gpu/drm/i915/i915_gem_object.h
> > +++ b/drivers/gpu/drm/i915/i915_gem_object.h
> > @@ -169,7 +169,7 @@ struct drm_i915_gem_object {
> > struct reservation_object *resv;
> >
> > /** References from framebuffers, locks out tiling changes. */
> > - atomic_t framebuffer_references;
> > + unsigned int framebuffer_references;
> >
> > /** Record of address bit 17 of each page at last unbind. */
> > unsigned long *bit_17;
> > @@ -263,6 +263,16 @@ extern void drm_gem_object_unreference(struct
> > drm_gem_object *);
> > __deprecated
> > extern void drm_gem_object_unreference_unlocked(struct drm_gem_object *);
> >
> > +static inline void i915_gem_object_lock(struct drm_i915_gem_object *obj)
> > +{
> > + reservation_object_lock(obj->resv, NULL);
> > +}
> > +
> > +static inline void i915_gem_object_unlock(struct drm_i915_gem_object *obj)
> > +{
> > + reservation_object_unlock(obj->resv);
> > +}
> > +
> > static inline bool
> > i915_gem_object_has_struct_page(const struct drm_i915_gem_object *obj)
> > {
> > @@ -303,6 +313,12 @@ i915_gem_object_clear_active_reference(struct
> > drm_i915_gem_object *obj)
> >
> > void __i915_gem_object_release_unless_active(struct drm_i915_gem_object
> > *obj);
> >
> > +static inline bool
> > +i915_gem_object_is_framebuffer(const struct drm_i915_gem_object *obj)
> > +{
> > + return READ_ONCE(obj->framebuffer_references);
> > +}
> > +
> > static inline unsigned int
> > i915_gem_object_get_tiling(struct drm_i915_gem_object *obj)
> > {
> > diff --git a/drivers/gpu/drm/i915/i915_gem_shrinker.c
> > b/drivers/gpu/drm/i915/i915_gem_shrinker.c
> > index 7e3bb48e043e..630697001b38 100644
> > --- a/drivers/gpu/drm/i915/i915_gem_shrinker.c
> > +++ b/drivers/gpu/drm/i915/i915_gem_shrinker.c
> > @@ -210,7 +210,7 @@ i915_gem_shrink(struct drm_i915_private *dev_priv,
> >
> > if (!(flags & I915_SHRINK_ACTIVE) &&
> > (i915_gem_object_is_active(obj) ||
> > -atomic_read(&obj->framebuffer_references)))
> > +i915_gem_object_is_framebuffer(obj)))
> > continue;
> >
> > if (!can_release_pages(obj))
> > diff --git a/drivers/gpu/drm/i915/i915_gem_tiling.c
> > b/drivers/gpu/drm/i915/i915_gem_tiling.c
> > index c1d669e32f41..ad5e05f6b836 100644
> > --- a/drivers/gpu/drm/i915/i915_gem_tiling.c
> > +++ b/drivers/gpu/drm/i915/i915_gem_tiling.c
> > @@ -238,7 +238,7 @@ i915_gem_object_set_tiling(struct drm_i915_gem_object
> > *obj,
> > if ((tiling | stride) == obj->tiling_and_stride)
> > return 0;
> >
> > - if (atomic_read(&obj->framebuffer_references))
> > + if (i915_gem_object_is_framebuffer(obj))
> > return -EBUSY;
> >
> > /* We need to rebind the object if its current allocation
> > @@ -258,6 +258,12 @@ i915_gem_object_set_tiling(struct drm_i915_gem_object
> > *obj,
> > if (err)
> > return err;
> >
> > + i915_gem_object_lock(obj);
> > + if (i915_gem_object_is_framebuffer(obj)) {
> > + i915_gem_object_unlock(obj);
> > + return -EBUSY;
> > + }
> > +
> > /* If the memory has unknown (i.e. varying) swizzling, we pin the
> > * pages to prevent them being swapped out and causing corruption
> > * due to the change in swizzling.
> > @@ -294,6 +300,7 @@ i915_gem_object_set_tiling(struct drm_i915_gem_object
> > *obj,
> > }
> >
> > obj->tiling_and_stride = tiling | stride;
> > + i915_gem_object_unlock(obj);
> >
> > /* Force the fence to be reacquired for GTT access */
> > i915_gem_release_mmap(obj);
> > diff --git a/drivers/gpu/drm/i915/intel_display.c
> > b/drivers/gpu/drm/i915/intel_display.c
> > index 77936ddd860a..62a1e628e399 100644
> > --- a/drivers/gpu/drm/i915/intel_display.c
> > +++ b/drivers/gpu/drm/i915/i
Re: [Intel-gfx] [PATCH 2/2] drm/i915: Prevent concurrent tiling/framebuffer modifications
On Tue, Feb 28, 2017 at 04:22:33PM +, Chris Wilson wrote:
> Reintroduce a lock around tiling vs framebuffer creation to prevent
> modification of the obj->tiling_and_stride whilst the framebuffer is
> being created. Rather than use struct_mutex once again, use the
> per-object lock - this will also be required in future to prevent
> changing the tiling whilst submitting rendering.
>
> Fixes: 24dbf51a5517 ("drm/i915: struct_mutex is not required for allocating
> the framebuffer")
> Signed-off-by: Chris Wilson
> Cc: Ville Syrjälä
> ---
> drivers/gpu/drm/i915/i915_gem_object.h | 18 +-
> drivers/gpu/drm/i915/i915_gem_shrinker.c | 2 +-
> drivers/gpu/drm/i915/i915_gem_tiling.c | 9 -
> drivers/gpu/drm/i915/intel_display.c | 25 -
> 4 files changed, 42 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_gem_object.h
> b/drivers/gpu/drm/i915/i915_gem_object.h
> index ad1bc0b1a0c2..8c02c8ec2a3b 100644
> --- a/drivers/gpu/drm/i915/i915_gem_object.h
> +++ b/drivers/gpu/drm/i915/i915_gem_object.h
> @@ -169,7 +169,7 @@ struct drm_i915_gem_object {
> struct reservation_object *resv;
>
> /** References from framebuffers, locks out tiling changes. */
> - atomic_t framebuffer_references;
> + unsigned int framebuffer_references;
>
> /** Record of address bit 17 of each page at last unbind. */
> unsigned long *bit_17;
> @@ -263,6 +263,16 @@ extern void drm_gem_object_unreference(struct
> drm_gem_object *);
> __deprecated
> extern void drm_gem_object_unreference_unlocked(struct drm_gem_object *);
>
> +static inline void i915_gem_object_lock(struct drm_i915_gem_object *obj)
> +{
> + reservation_object_lock(obj->resv, NULL);
> +}
> +
> +static inline void i915_gem_object_unlock(struct drm_i915_gem_object *obj)
> +{
> + reservation_object_unlock(obj->resv);
> +}
> +
> static inline bool
> i915_gem_object_has_struct_page(const struct drm_i915_gem_object *obj)
> {
> @@ -303,6 +313,12 @@ i915_gem_object_clear_active_reference(struct
> drm_i915_gem_object *obj)
>
> void __i915_gem_object_release_unless_active(struct drm_i915_gem_object
> *obj);
>
> +static inline bool
> +i915_gem_object_is_framebuffer(const struct drm_i915_gem_object *obj)
> +{
> + return READ_ONCE(obj->framebuffer_references);
> +}
> +
> static inline unsigned int
> i915_gem_object_get_tiling(struct drm_i915_gem_object *obj)
> {
> diff --git a/drivers/gpu/drm/i915/i915_gem_shrinker.c
> b/drivers/gpu/drm/i915/i915_gem_shrinker.c
> index 7e3bb48e043e..630697001b38 100644
> --- a/drivers/gpu/drm/i915/i915_gem_shrinker.c
> +++ b/drivers/gpu/drm/i915/i915_gem_shrinker.c
> @@ -210,7 +210,7 @@ i915_gem_shrink(struct drm_i915_private *dev_priv,
>
> if (!(flags & I915_SHRINK_ACTIVE) &&
> (i915_gem_object_is_active(obj) ||
> - atomic_read(&obj->framebuffer_references)))
> + i915_gem_object_is_framebuffer(obj)))
> continue;
>
> if (!can_release_pages(obj))
> diff --git a/drivers/gpu/drm/i915/i915_gem_tiling.c
> b/drivers/gpu/drm/i915/i915_gem_tiling.c
> index c1d669e32f41..ad5e05f6b836 100644
> --- a/drivers/gpu/drm/i915/i915_gem_tiling.c
> +++ b/drivers/gpu/drm/i915/i915_gem_tiling.c
> @@ -238,7 +238,7 @@ i915_gem_object_set_tiling(struct drm_i915_gem_object
> *obj,
> if ((tiling | stride) == obj->tiling_and_stride)
> return 0;
>
> - if (atomic_read(&obj->framebuffer_references))
> + if (i915_gem_object_is_framebuffer(obj))
> return -EBUSY;
>
> /* We need to rebind the object if its current allocation
> @@ -258,6 +258,12 @@ i915_gem_object_set_tiling(struct drm_i915_gem_object
> *obj,
> if (err)
> return err;
>
> + i915_gem_object_lock(obj);
> + if (i915_gem_object_is_framebuffer(obj)) {
> + i915_gem_object_unlock(obj);
> + return -EBUSY;
> + }
> +
> /* If the memory has unknown (i.e. varying) swizzling, we pin the
>* pages to prevent them being swapped out and causing corruption
>* due to the change in swizzling.
> @@ -294,6 +300,7 @@ i915_gem_object_set_tiling(struct drm_i915_gem_object
> *obj,
> }
>
> obj->tiling_and_stride = tiling | stride;
> + i915_gem_object_unlock(obj);
>
> /* Force the fence to be reacquired for GTT access */
> i915_gem_release_mmap(obj);
> diff --git a/drivers/gpu/drm/i915/intel_display.c
> b/drivers/gpu/drm/i915/intel_display.c
> index 77936ddd860a..62a1e628e399 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -14255,7 +14255,10 @@ static void intel_user_framebuffer_destroy(struct
> drm_framebuffer *fb)
>
> drm_framebuffer_cleanup(fb);
>
> - WARN_ON(atomic_dec_return(&intel_fb->obj->framebuffer_references)
Re: [Intel-gfx] [PATCH 2/2] drm/i915: Prevent concurrent tiling/framebuffer modifications
On Tue, Feb 28, 2017 at 04:22:33PM +, Chris Wilson wrote: > Reintroduce a lock around tiling vs framebuffer creation to prevent > modification of the obj->tiling_and_stride whilst the framebuffer is > being created. Rather than use struct_mutex once again, use the > per-object lock - this will also be required in future to prevent > changing the tiling whilst submitting rendering. It also means that we can't create a framebuffer whilst submitting rendering to/from the object (on this or other device). However, the gen2/gen3 fence requirement means that we will want some serialisation between set_tiling_ioctl and execbuffer_ioctl - and so the ww_mutex still seems apt. -Chris -- Chris Wilson, Intel Open Source Technology Centre ___ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx
[Intel-gfx] [PATCH 2/2] drm/i915: Prevent concurrent tiling/framebuffer modifications
Reintroduce a lock around tiling vs framebuffer creation to prevent
modification of the obj->tiling_and_stride whilst the framebuffer is
being created. Rather than use struct_mutex once again, use the
per-object lock - this will also be required in future to prevent
changing the tiling whilst submitting rendering.
Fixes: 24dbf51a5517 ("drm/i915: struct_mutex is not required for allocating the
framebuffer")
Signed-off-by: Chris Wilson
Cc: Ville Syrjälä
---
drivers/gpu/drm/i915/i915_gem_object.h | 18 +-
drivers/gpu/drm/i915/i915_gem_shrinker.c | 2 +-
drivers/gpu/drm/i915/i915_gem_tiling.c | 9 -
drivers/gpu/drm/i915/intel_display.c | 25 -
4 files changed, 42 insertions(+), 12 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_gem_object.h
b/drivers/gpu/drm/i915/i915_gem_object.h
index ad1bc0b1a0c2..8c02c8ec2a3b 100644
--- a/drivers/gpu/drm/i915/i915_gem_object.h
+++ b/drivers/gpu/drm/i915/i915_gem_object.h
@@ -169,7 +169,7 @@ struct drm_i915_gem_object {
struct reservation_object *resv;
/** References from framebuffers, locks out tiling changes. */
- atomic_t framebuffer_references;
+ unsigned int framebuffer_references;
/** Record of address bit 17 of each page at last unbind. */
unsigned long *bit_17;
@@ -263,6 +263,16 @@ extern void drm_gem_object_unreference(struct
drm_gem_object *);
__deprecated
extern void drm_gem_object_unreference_unlocked(struct drm_gem_object *);
+static inline void i915_gem_object_lock(struct drm_i915_gem_object *obj)
+{
+ reservation_object_lock(obj->resv, NULL);
+}
+
+static inline void i915_gem_object_unlock(struct drm_i915_gem_object *obj)
+{
+ reservation_object_unlock(obj->resv);
+}
+
static inline bool
i915_gem_object_has_struct_page(const struct drm_i915_gem_object *obj)
{
@@ -303,6 +313,12 @@ i915_gem_object_clear_active_reference(struct
drm_i915_gem_object *obj)
void __i915_gem_object_release_unless_active(struct drm_i915_gem_object *obj);
+static inline bool
+i915_gem_object_is_framebuffer(const struct drm_i915_gem_object *obj)
+{
+ return READ_ONCE(obj->framebuffer_references);
+}
+
static inline unsigned int
i915_gem_object_get_tiling(struct drm_i915_gem_object *obj)
{
diff --git a/drivers/gpu/drm/i915/i915_gem_shrinker.c
b/drivers/gpu/drm/i915/i915_gem_shrinker.c
index 7e3bb48e043e..630697001b38 100644
--- a/drivers/gpu/drm/i915/i915_gem_shrinker.c
+++ b/drivers/gpu/drm/i915/i915_gem_shrinker.c
@@ -210,7 +210,7 @@ i915_gem_shrink(struct drm_i915_private *dev_priv,
if (!(flags & I915_SHRINK_ACTIVE) &&
(i915_gem_object_is_active(obj) ||
-atomic_read(&obj->framebuffer_references)))
+i915_gem_object_is_framebuffer(obj)))
continue;
if (!can_release_pages(obj))
diff --git a/drivers/gpu/drm/i915/i915_gem_tiling.c
b/drivers/gpu/drm/i915/i915_gem_tiling.c
index c1d669e32f41..ad5e05f6b836 100644
--- a/drivers/gpu/drm/i915/i915_gem_tiling.c
+++ b/drivers/gpu/drm/i915/i915_gem_tiling.c
@@ -238,7 +238,7 @@ i915_gem_object_set_tiling(struct drm_i915_gem_object *obj,
if ((tiling | stride) == obj->tiling_and_stride)
return 0;
- if (atomic_read(&obj->framebuffer_references))
+ if (i915_gem_object_is_framebuffer(obj))
return -EBUSY;
/* We need to rebind the object if its current allocation
@@ -258,6 +258,12 @@ i915_gem_object_set_tiling(struct drm_i915_gem_object *obj,
if (err)
return err;
+ i915_gem_object_lock(obj);
+ if (i915_gem_object_is_framebuffer(obj)) {
+ i915_gem_object_unlock(obj);
+ return -EBUSY;
+ }
+
/* If the memory has unknown (i.e. varying) swizzling, we pin the
* pages to prevent them being swapped out and causing corruption
* due to the change in swizzling.
@@ -294,6 +300,7 @@ i915_gem_object_set_tiling(struct drm_i915_gem_object *obj,
}
obj->tiling_and_stride = tiling | stride;
+ i915_gem_object_unlock(obj);
/* Force the fence to be reacquired for GTT access */
i915_gem_release_mmap(obj);
diff --git a/drivers/gpu/drm/i915/intel_display.c
b/drivers/gpu/drm/i915/intel_display.c
index 77936ddd860a..62a1e628e399 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -14255,7 +14255,10 @@ static void intel_user_framebuffer_destroy(struct
drm_framebuffer *fb)
drm_framebuffer_cleanup(fb);
- WARN_ON(atomic_dec_return(&intel_fb->obj->framebuffer_references) < 0);
+ i915_gem_object_lock(intel_fb->obj);
+ WARN_ON(!intel_fb->obj->framebuffer_references--);
+ i915_gem_object_unlock(intel_fb->obj);
+
i915_gem_object_put(intel_fb->obj);
kfree(intel_fb);
@@ -14332,12 +
