[Intel-gfx] [RESEND PATCH 2/3] drm/i915: Add vfunc for pread

[Janusz Krzysztofik]

From: Matthew Auld <matthew.auld at intel.com>

Similar to pwrite, we need pread for (better) support of non-GTT
backends.

Signed-off-by: Matthew Auld <matthew.auld at intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
Cc: Abdiel Janulgue <abdiel.janulgue at linux.intel.com>
Signed-off-by: Janusz Krzysztofik <janusz.krzysztofik at intel.com>
Cc: Michal Wajdeczko <michal.wajdeczko at intel.com>
---
 drivers/gpu/drm/i915/gem/i915_gem_object_types.h | 2 ++
 drivers/gpu/drm/i915/i915_gem.c                  | 6 ++++++
 2 files changed, 8 insertions(+)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_object_types.h b/drivers/gpu/drm/i915/gem/i915_gem_object_types.h
index a387e3ee728b..3ad13556ed75 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_object_types.h
+++ b/drivers/gpu/drm/i915/gem/i915_gem_object_types.h
@@ -55,6 +55,8 @@ struct drm_i915_gem_object_ops {
 	void (*truncate)(struct drm_i915_gem_object *obj);
 	void (*writeback)(struct drm_i915_gem_object *obj);
 
+	int (*pread)(struct drm_i915_gem_object *obj,
+		     const struct drm_i915_gem_pread *arg);
 	int (*pwrite)(struct drm_i915_gem_object *obj,
 		      const struct drm_i915_gem_pwrite *arg);
 
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index dd0a3271b4e2..bb9121887ce6 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -469,6 +469,12 @@ i915_gem_pread_ioctl(struct drm_device *dev, void *data,
 
 	trace_i915_gem_object_pread(obj, args->offset, args->size);
 
+	if (obj->ops->pread) {
+		ret = obj->ops->pread(obj, args);
+		if (ret != -ENODEV)
+			goto out;
+	}
+
 	ret = i915_gem_object_wait(obj,
 				   I915_WAIT_INTERRUPTIBLE,
 				   MAX_SCHEDULE_TIMEOUT);
-- 
2.21.0