[1/4] drm: Add helpers for locking an array of BO reservations.
diff mbox series

Message ID 20190308161716.2466-2-eric@anholt.net
State New
Headers show
Series
  • drm/v3d: Add drm core helper, use shmem helpers
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Commit Message

Eric Anholt March 8, 2019, 4:17 p.m. UTC
Now that we have the reservation object in the GEM object, it's easy
to provide a helper for this common case.  Noticed while reviewing
panfrost and lima drivers.  This particular version came out of v3d,
which in turn was a copy from vc4.

Signed-off-by: Eric Anholt <eric@anholt.net>
---
 drivers/gpu/drm/drm_gem.c | 76 +++++++++++++++++++++++++++++++++++++++
 include/drm/drm_gem.h     |  4 +++
 2 files changed, 80 insertions(+)

Comments

Rob Herring March 8, 2019, 5:33 p.m. UTC | #1
On Fri, Mar 8, 2019 at 10:17 AM Eric Anholt <eric@anholt.net> wrote:
>
> Now that we have the reservation object in the GEM object, it's easy
> to provide a helper for this common case.  Noticed while reviewing
> panfrost and lima drivers.  This particular version came out of v3d,
> which in turn was a copy from vc4.
>
> Signed-off-by: Eric Anholt <eric@anholt.net>
> ---
>  drivers/gpu/drm/drm_gem.c | 76 +++++++++++++++++++++++++++++++++++++++
>  include/drm/drm_gem.h     |  4 +++
>  2 files changed, 80 insertions(+)

Sweet! I was about to go write this same patch. You are changing the
license from GPL to MIT copying the v3d version, but I guess you have
rights to do that.

FWIW,

Acked-by: Rob Herring <robh@kernel.org>

Rob
Eric Anholt March 8, 2019, 5:46 p.m. UTC | #2
Rob Herring <robh@kernel.org> writes:

> On Fri, Mar 8, 2019 at 10:17 AM Eric Anholt <eric@anholt.net> wrote:
>>
>> Now that we have the reservation object in the GEM object, it's easy
>> to provide a helper for this common case.  Noticed while reviewing
>> panfrost and lima drivers.  This particular version came out of v3d,
>> which in turn was a copy from vc4.
>>
>> Signed-off-by: Eric Anholt <eric@anholt.net>
>> ---
>>  drivers/gpu/drm/drm_gem.c | 76 +++++++++++++++++++++++++++++++++++++++
>>  include/drm/drm_gem.h     |  4 +++
>>  2 files changed, 80 insertions(+)
>
> Sweet! I was about to go write this same patch. You are changing the
> license from GPL to MIT copying the v3d version, but I guess you have
> rights to do that.

The original vc4 copy I had was MIT, anyway.
Eric Anholt March 12, 2019, 5:37 p.m. UTC | #3
Rob Herring <robh@kernel.org> writes:

> On Fri, Mar 8, 2019 at 10:17 AM Eric Anholt <eric@anholt.net> wrote:
>>
>> Now that we have the reservation object in the GEM object, it's easy
>> to provide a helper for this common case.  Noticed while reviewing
>> panfrost and lima drivers.  This particular version came out of v3d,
>> which in turn was a copy from vc4.
>>
>> Signed-off-by: Eric Anholt <eric@anholt.net>
>> ---
>>  drivers/gpu/drm/drm_gem.c | 76 +++++++++++++++++++++++++++++++++++++++
>>  include/drm/drm_gem.h     |  4 +++
>>  2 files changed, 80 insertions(+)
>
> Sweet! I was about to go write this same patch. You are changing the
> license from GPL to MIT copying the v3d version, but I guess you have
> rights to do that.
>
> FWIW,
>
> Acked-by: Rob Herring <robh@kernel.org>

Was this just for this one patch, or the series?  I don't think I can
merge without a consumer.
Rob Herring March 12, 2019, 7:50 p.m. UTC | #4
On Tue, Mar 12, 2019 at 12:37 PM Eric Anholt <eric@anholt.net> wrote:
>
> Rob Herring <robh@kernel.org> writes:
>
> > On Fri, Mar 8, 2019 at 10:17 AM Eric Anholt <eric@anholt.net> wrote:
> >>
> >> Now that we have the reservation object in the GEM object, it's easy
> >> to provide a helper for this common case.  Noticed while reviewing
> >> panfrost and lima drivers.  This particular version came out of v3d,
> >> which in turn was a copy from vc4.
> >>
> >> Signed-off-by: Eric Anholt <eric@anholt.net>
> >> ---
> >>  drivers/gpu/drm/drm_gem.c | 76 +++++++++++++++++++++++++++++++++++++++
> >>  include/drm/drm_gem.h     |  4 +++
> >>  2 files changed, 80 insertions(+)
> >
> > Sweet! I was about to go write this same patch. You are changing the
> > license from GPL to MIT copying the v3d version, but I guess you have
> > rights to do that.
> >
> > FWIW,
> >
> > Acked-by: Rob Herring <robh@kernel.org>
>
> Was this just for this one patch, or the series?  I don't think I can
> merge without a consumer.

Sure, it can be for patches 1-3. Patch 4 is dependent on me sending
out the shmem helpers again.

Rob
Eric Anholt March 14, 2019, 4:28 p.m. UTC | #5
Rob Herring <robh@kernel.org> writes:

> On Tue, Mar 12, 2019 at 12:37 PM Eric Anholt <eric@anholt.net> wrote:
>>
>> Rob Herring <robh@kernel.org> writes:
>>
>> > On Fri, Mar 8, 2019 at 10:17 AM Eric Anholt <eric@anholt.net> wrote:
>> >>
>> >> Now that we have the reservation object in the GEM object, it's easy
>> >> to provide a helper for this common case.  Noticed while reviewing
>> >> panfrost and lima drivers.  This particular version came out of v3d,
>> >> which in turn was a copy from vc4.
>> >>
>> >> Signed-off-by: Eric Anholt <eric@anholt.net>
>> >> ---
>> >>  drivers/gpu/drm/drm_gem.c | 76 +++++++++++++++++++++++++++++++++++++++
>> >>  include/drm/drm_gem.h     |  4 +++
>> >>  2 files changed, 80 insertions(+)
>> >
>> > Sweet! I was about to go write this same patch. You are changing the
>> > license from GPL to MIT copying the v3d version, but I guess you have
>> > rights to do that.
>> >
>> > FWIW,
>> >
>> > Acked-by: Rob Herring <robh@kernel.org>
>>
>> Was this just for this one patch, or the series?  I don't think I can
>> merge without a consumer.
>
> Sure, it can be for patches 1-3. Patch 4 is dependent on me sending
> out the shmem helpers again.

Thanks.  Pushed the first 3 now.

Patch
diff mbox series

diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c
index ad124f5a6f4d..9fd804f7d7ca 100644
--- a/drivers/gpu/drm/drm_gem.c
+++ b/drivers/gpu/drm/drm_gem.c
@@ -1233,3 +1233,79 @@  void drm_gem_vunmap(struct drm_gem_object *obj, void *vaddr)
 		obj->dev->driver->gem_prime_vunmap(obj, vaddr);
 }
 EXPORT_SYMBOL(drm_gem_vunmap);
+
+/**
+ * drm_gem_lock_bo_reservations - Sets up the ww context and acquires
+ * the lock on an array of GEM objects.
+ *
+ * Once you've locked your reservations, you'll want to set up space
+ * for your shared fences (if applicable), submit your job, then
+ * drm_gem_unlock_reservations().
+ *
+ * @acquire_ctx - struct ww_acquire_ctx that will be initialized as
+ * part of tracking this set of locked reservations.
+ */
+int
+drm_gem_lock_reservations(struct drm_gem_object **objs, int count,
+			  struct ww_acquire_ctx *acquire_ctx)
+{
+	int contended = -1;
+	int i, ret;
+
+	ww_acquire_init(acquire_ctx, &reservation_ww_class);
+
+retry:
+	if (contended != -1) {
+		struct drm_gem_object *obj = objs[contended];
+
+		ret = ww_mutex_lock_slow_interruptible(&obj->resv->lock,
+						       acquire_ctx);
+		if (ret) {
+			ww_acquire_done(acquire_ctx);
+			return ret;
+		}
+	}
+
+	for (i = 0; i < count; i++) {
+		if (i == contended)
+			continue;
+
+		ret = ww_mutex_lock_interruptible(&objs[i]->resv->lock,
+						  acquire_ctx);
+		if (ret) {
+			int j;
+
+			for (j = 0; j < i; j++)
+				ww_mutex_unlock(&objs[j]->resv->lock);
+
+			if (contended != -1 && contended >= i)
+				ww_mutex_unlock(&objs[contended]->resv->lock);
+
+			if (ret == -EDEADLK) {
+				contended = i;
+				goto retry;
+			}
+
+			ww_acquire_done(acquire_ctx);
+			return ret;
+		}
+	}
+
+	ww_acquire_done(acquire_ctx);
+
+	return 0;
+}
+EXPORT_SYMBOL(drm_gem_lock_reservations);
+
+void
+drm_gem_unlock_reservations(struct drm_gem_object **objs, int count,
+			    struct ww_acquire_ctx *acquire_ctx)
+{
+	int i;
+
+	for (i = 0; i < count; i++)
+		ww_mutex_unlock(&objs[i]->resv->lock);
+
+	ww_acquire_fini(acquire_ctx);
+}
+EXPORT_SYMBOL(drm_gem_unlock_reservations);
diff --git a/include/drm/drm_gem.h b/include/drm/drm_gem.h
index 25f1ff2df464..2955aaab3dca 100644
--- a/include/drm/drm_gem.h
+++ b/include/drm/drm_gem.h
@@ -384,6 +384,10 @@  void drm_gem_put_pages(struct drm_gem_object *obj, struct page **pages,
 struct drm_gem_object *drm_gem_object_lookup(struct drm_file *filp, u32 handle);
 long drm_gem_reservation_object_wait(struct drm_file *filep, u32 handle,
 				    bool wait_all, unsigned long timeout);
+int drm_gem_lock_reservations(struct drm_gem_object **objs, int count,
+			      struct ww_acquire_ctx *acquire_ctx);
+void drm_gem_unlock_reservations(struct drm_gem_object **objs, int count,
+				 struct ww_acquire_ctx *acquire_ctx);
 int drm_gem_dumb_map_offset(struct drm_file *file, struct drm_device *dev,
 			    u32 handle, u64 *offset);
 int drm_gem_dumb_destroy(struct drm_file *file,