[Intel-gfx] [PATCH v6 02/14] drm/i915: Add i915_gem_object_write() to i915_gem.c

[yu.dai at intel.com]

From: "Michael H. Nguyen" <michael.h.nguyen at intel.com>

i915_gem_object_write() is a generic function to copy data from
user memory to gem object.

Issue: VIZ-4884
Signed-off-by: Alex Dai <yu.dai at intel.com>
---
 drivers/gpu/drm/i915/i915_drv.h |  2 ++
 drivers/gpu/drm/i915/i915_gem.c | 28 ++++++++++++++++++++++++++++
 2 files changed, 30 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 31e13e9..f5068cb 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -2646,6 +2646,8 @@ void i915_init_vm(struct drm_i915_private *dev_priv,
 		  struct i915_address_space *vm);
 void i915_gem_free_object(struct drm_gem_object *obj);
 void i915_gem_vma_destroy(struct i915_vma *vma);
+int i915_gem_object_write(struct drm_i915_gem_object *obj,
+			const void *data, const size_t size);
 
 /* Flags used by pin/bind&friends. */
 #define PIN_MAPPABLE	(1<<0)
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index db59821..fabe8de 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -5238,3 +5238,31 @@ bool i915_gem_obj_is_pinned(struct drm_i915_gem_object *obj)
 	return false;
 }
 
+/* Fill the @obj with the @size amount of @data */
+int i915_gem_object_write(struct drm_i915_gem_object *obj,
+			const void *data, const size_t size)
+{
+	struct sg_table *sg;
+	size_t bytes;
+	int ret;
+
+	ret = i915_gem_object_get_pages(obj);
+	if (ret)
+		return ret;
+
+	i915_gem_object_pin_pages(obj);
+
+	sg = obj->pages;
+
+	bytes = sg_copy_from_buffer(sg->sgl, sg->nents, (void *)data, size);
+
+	i915_gem_object_unpin_pages(obj);
+
+	if (WARN_ON(bytes != size)) {
+		DRM_ERROR("Uncompleted copy, wrote %zu of %zu", bytes, size);
+		i915_gem_object_put_pages(obj);
+		return -EIO;
+	}
+
+	return 0;
+}
-- 
1.9.1