[Intel-gfx] [PATCH 01/15] drm/i915: Add i915_gem_object_write() to i915_gem.c

[Dave Gordon]

From: Alex Dai <yu.dai at intel.com>

i915_gem_object_write() is a generic function to copy data from a plain
linear buffer to a paged gem object.

We will need this for the microcontroller firmware loading support code.

Issue: VIZ-4884
Signed-off-by: Alex Dai <yu.dai at intel.com>
Signed-off-by: Dave Gordon <david.s.gordon 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 611fbd8..9094c06 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -2713,6 +2713,8 @@ void *i915_gem_object_alloc(struct drm_device *dev);
 void i915_gem_object_free(struct drm_i915_gem_object *obj);
 void i915_gem_object_init(struct drm_i915_gem_object *obj,
 			 const struct drm_i915_gem_object_ops *ops);
+int i915_gem_object_write(struct drm_i915_gem_object *obj,
+			  const void *data, size_t size);
 struct drm_i915_gem_object *i915_gem_alloc_object(struct drm_device *dev,
 						  size_t size);
 void i915_init_vm(struct drm_i915_private *dev_priv,
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index be35f04..75d63c2 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -5392,3 +5392,31 @@ 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, 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("Incomplete copy, wrote %zu of %zu", bytes, size);
+		i915_gem_object_put_pages(obj);
+		return -EIO;
+	}
+
+	return 0;
+}
-- 
1.7.9.5