drm/cma: add low-level hook functions to use prime helpers

Instead of using the dma_buf functionality for GEM CMA, we can use prime
helpers if we can provide low-level hook functions for GEM CMA.

Signed-off-by: Joonyoung Shim <jy0922.shim@samsung.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 79 insertions, 0 deletions

diff --git a/drivers/gpu/drm/drm_gem_cma_helper.c b/drivers/gpu/drm/drm_gem_cma_helper.c
index ce063970d68c..83a45e5cf04e 100644
--- a/drivers/gpu/drm/drm_gem_cma_helper.c
+++ b/drivers/gpu/drm/drm_gem_cma_helper.c
@@ -602,3 +602,82 @@ error_gem_free:
         return ERR_PTR(ret);
 }
 EXPORT_SYMBOL_GPL(drm_gem_cma_dmabuf_import);
+
+/* low-level interface prime helpers */
+struct sg_table *drm_gem_cma_prime_get_sg_table(struct drm_gem_object *obj)
+{
+        struct drm_gem_cma_object *cma_obj = to_drm_gem_cma_obj(obj);
+        struct sg_table *sgt;
+        int ret;
+
+        sgt = kzalloc(sizeof(*sgt), GFP_KERNEL);
+        if (!sgt)
+                return NULL;
+
+        ret = dma_get_sgtable(obj->dev->dev, sgt, cma_obj->vaddr,
+                              cma_obj->paddr, obj->size);
+        if (ret < 0)
+                goto out;
+
+        return sgt;
+
+out:
+        kfree(sgt);
+        return NULL;
+}
+EXPORT_SYMBOL_GPL(drm_gem_cma_prime_get_sg_table);
+
+struct drm_gem_object *
+drm_gem_cma_prime_import_sg_table(struct drm_device *dev, size_t size,
+                                  struct sg_table *sgt)
+{
+        struct drm_gem_cma_object *cma_obj;
+
+        if (sgt->nents != 1)
+                return ERR_PTR(-EINVAL);
+
+        /* Create a CMA GEM buffer. */
+        cma_obj = __drm_gem_cma_create(dev, size);
+        if (IS_ERR(cma_obj))
+                return ERR_PTR(PTR_ERR(cma_obj));
+
+        cma_obj->paddr = sg_dma_address(sgt->sgl);
+        cma_obj->sgt = sgt;
+
+        DRM_DEBUG_PRIME("dma_addr = 0x%x, size = %zu\n", cma_obj->paddr, size);
+
+        return &cma_obj->base;
+}
+EXPORT_SYMBOL_GPL(drm_gem_cma_prime_import_sg_table);
+
+int drm_gem_cma_prime_mmap(struct drm_gem_object *obj,
+                           struct vm_area_struct *vma)
+{
+        struct drm_gem_cma_object *cma_obj;
+        struct drm_device *dev = obj->dev;
+        int ret;
+
+        mutex_lock(&dev->struct_mutex);
+        ret = drm_gem_mmap_obj(obj, obj->size, vma);
+        mutex_unlock(&dev->struct_mutex);
+        if (ret < 0)
+                return ret;
+
+        cma_obj = to_drm_gem_cma_obj(obj);
+        return drm_gem_cma_mmap_obj(cma_obj, vma);
+}
+EXPORT_SYMBOL_GPL(drm_gem_cma_prime_mmap);
+
+void *drm_gem_cma_prime_vmap(struct drm_gem_object *obj)
+{
+        struct drm_gem_cma_object *cma_obj = to_drm_gem_cma_obj(obj);
+
+        return cma_obj->vaddr;
+}
+EXPORT_SYMBOL_GPL(drm_gem_cma_prime_vmap);
+
+void drm_gem_cma_prime_vunmap(struct drm_gem_object *obj, void *vaddr)
+{
+        /* Nothing to do */
+}
+EXPORT_SYMBOL_GPL(drm_gem_cma_prime_vunmap);