drm/i915/gem: Allow backends to override pread implementation

As there are more and more complicated interactions between the different
backing stores and userspace, push the control into the backends rather
than accumulate them all inside the ioctl handlers.

Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20201105154934.16022-1-chris@chris-wilson.co.uk
(cherry picked from commit 0049b688459b846f819b6e51c24cd0781fcfde41)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

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 b5c15557cc87b8eaced85355b8e1eb5d4abfcabd..d6711caa7f399564120d7eb9dca039bcf3183bd0 100644 (file)
--- a/drivers/gpu/drm/i915/gem/i915_gem_object_types.h
+++ b/drivers/gpu/drm/i915/gem/i915_gem_object_types.h
@@ -56,6 +56,8 @@ 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 bb0c12975f38e577309d099544edbd097a7405f7..d58fe1ddc3e153a780726266e5f9aa0e19844fed 100644 (file)
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -527,6 +527,12 @@ i915_gem_pread_ioctl(struct drm_device *dev, void *data,
 
        trace_i915_gem_object_pread(obj, args->offset, args->size);
 
+       ret = -ENODEV;
+       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);