Allow for the creation of GEM objects backed by stolen memory. As these
are not backed by ordinary pages, we create a fake dma mapping and store
the address in the scatterlist rather than obj->pages.
Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
drivers/gpu/drm/i915/i915_drv.h | 3 +
drivers/gpu/drm/i915/i915_gem.c | 2 +
drivers/gpu/drm/i915/i915_gem_gtt.c | 2 +-
drivers/gpu/drm/i915/i915_gem_stolen.c | 110 ++++++++++++++++++++++++++++++++
4 files changed, 116 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 8850b19..d487301 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1378,6 +1378,9 @@ int i915_gem_evict_everything(struct drm_device *dev);
int i915_gem_init_stolen(struct drm_device *dev);
int i915_gem_stolen_setup_compression(struct drm_device *dev);
void i915_gem_cleanup_stolen(struct drm_device *dev);
+struct drm_i915_gem_object *
+i915_gem_object_create_stolen(struct drm_device *dev, u32 size);
+void i915_gem_object_release_stolen(struct drm_i915_gem_object *obj);
/* i915_gem_tiling.c */
void i915_gem_detect_bit_6_swizzle(struct drm_device *dev);
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index e72f661..2a642f5 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -3549,6 +3549,8 @@ void i915_gem_free_object(struct drm_gem_object *gem_obj)
i915_gem_object_put_pages_gtt(obj);
i915_gem_object_free_mmap_offset(obj);
+ i915_gem_object_release_stolen(obj);
+
drm_gem_object_release(&obj->base);
i915_gem_info_remove_obj(dev_priv, obj->base.size);
diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
index fbdaf5a..e847caec 100644
--- a/drivers/gpu/drm/i915/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
@@ -398,7 +398,7 @@ void i915_gem_gtt_finish_object(struct drm_i915_gem_object *obj)
interruptible = do_idling(dev_priv);
- if (obj->sg_list) {
+ if (obj->sg_list && !obj->stolen) {
intel_gtt_unmap_memory(obj->sg_list, obj->num_sg);
obj->sg_list = NULL;
}
diff --git a/drivers/gpu/drm/i915/i915_gem_stolen.c b/drivers/gpu/drm/i915/i915_gem_stolen.c
index 5e10a23..0011006 100644
--- a/drivers/gpu/drm/i915/i915_gem_stolen.c
+++ b/drivers/gpu/drm/i915/i915_gem_stolen.c
@@ -211,3 +211,113 @@ int i915_gem_init_stolen(struct drm_device *dev)
return 0;
}
+
+struct scatterlist *
+i915_sg_create_for_stolen(struct drm_device *dev, u32 offset, u32 size)
+{
+ struct drm_i915_private *dev_priv = dev->dev_private;
+ struct scatterlist *sg;
+
+ /* We hide that we have no struct page backing our stolen object
+ * by wrapping the contiguous physical allocation with a fake
+ * dma mapping in a single scatterlist.
+ */
+
+ sg = kmalloc(sizeof(*sg), GFP_KERNEL);
+ if (sg == NULL)
+ return NULL;
+
+ sg_init_table(sg, 1);
+
+ sg->offset = offset;
+ sg->length = size;
+
+ sg_dma_address(sg) = dev_priv->mm.stolen_base + offset;
+ sg_dma_len(sg) = size;
+
+ return sg;
+}
+
+struct drm_i915_gem_object *
+_i915_gem_object_create_stolen(struct drm_device *dev,
+ struct drm_mm_node *stolen)
+{
+ struct drm_i915_gem_object *obj;
+ struct scatterlist *sg;
+
+ obj = kzalloc(sizeof(*obj), GFP_KERNEL);
+ if (obj == NULL)
+ return NULL;
+
+ if (drm_gem_private_object_init(dev, &obj->base, stolen->size))
+ goto cleanup;
+
+ sg = i915_sg_create_for_stolen(dev, stolen->start, stolen->size);
+ if (sg == NULL)
+ goto cleanup;
+
+ i915_gem_object_init(obj);
+
+ obj->stolen = stolen;
+
+ obj->base.write_domain = I915_GEM_DOMAIN_GTT;
+ obj->base.read_domains = I915_GEM_DOMAIN_GTT;
+ obj->cache_level = I915_CACHE_NONE;
+
+ obj->sg_list = sg;
+ obj->num_sg = 1;
+
+ return obj;
+
+cleanup:
+ kfree(obj);
+ return NULL;
+}
+
+struct drm_i915_gem_object *
+i915_gem_object_create_stolen(struct drm_device *dev, u32 size)
+{
+ struct drm_i915_private *dev_priv = dev->dev_private;
+ struct drm_i915_gem_object *obj;
+ struct drm_mm_node *stolen;
+
+ if (dev_priv->mm.stolen_base == 0)
+ return 0;
+
+ DRM_DEBUG_KMS("creating stolen object: size=%x\n", size);
+ if (size == 0)
+ return NULL;
+
+ stolen = drm_mm_search_free(&dev_priv->mm.stolen, size, 4096, 0);
+ if (stolen)
+ stolen = drm_mm_get_block(stolen, size, 4096);
+ if (stolen == NULL)
+ return NULL;
+
+ obj = _i915_gem_object_create_stolen(dev, stolen);
+ if (obj)
+ return obj;
+
+ drm_mm_put_block(stolen);
+ return NULL;
+}
+
+void
+i915_gem_object_release_stolen(struct drm_i915_gem_object *obj)
+{
+ if (obj->stolen) {
+ drm_mm_put_block(obj->stolen);
+ obj->stolen = NULL;
+ }
+
+ if (obj->sg_list) {
+ struct sg_table st;
+
+ st.sgl = obj->sg_list;
+ st.orig_nents = st.nents = obj->num_sg;
+
+ sg_free_table(&st);
+
+ obj->sg_list = NULL;
+ }
+}
--
1.7.10
