drm/exynos: added cache attribute support for gem.

with this patch, user application can set cache attribute(such as
cachable, writecombime or non-cachable) of the memory region allocated
by gem framework.

Signed-off-by: Inki Dae <inki.dae@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>

1 files changed, 39 insertions, 10 deletions

diff --git a/drivers/gpu/drm/exynos/exynos_drm_gem.c b/drivers/gpu/drm/exynos/exynos_drm_gem.c
index 1dffa8359f88..e8ab3beb4510 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_gem.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_gem.c
@@ -66,6 +66,22 @@ static int check_gem_flags(unsigned int flags)
         return 0;
 }
 
+static void update_vm_cache_attr(struct exynos_drm_gem_obj *obj,
+                                        struct vm_area_struct *vma)
+{
+        DRM_DEBUG_KMS("flags = 0x%x\n", obj->flags);
+
+        /* non-cachable as default. */
+        if (obj->flags & EXYNOS_BO_CACHABLE)
+                vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
+        else if (obj->flags & EXYNOS_BO_WC)
+                vma->vm_page_prot =
+                        pgprot_writecombine(vm_get_page_prot(vma->vm_flags));
+        else
+                vma->vm_page_prot =
+                        pgprot_noncached(vm_get_page_prot(vma->vm_flags));
+}
+
 static unsigned long roundup_gem_size(unsigned long size, unsigned int flags)
 {
         if (!IS_NONCONTIG_BUFFER(flags)) {
@@ -262,24 +278,24 @@ static int exynos_drm_gem_handle_create(struct drm_gem_object *obj,
 void exynos_drm_gem_destroy(struct exynos_drm_gem_obj *exynos_gem_obj)
 {
         struct drm_gem_object *obj;
+        struct exynos_drm_gem_buf *buf;
 
         DRM_DEBUG_KMS("%s\n", __FILE__);
 
-        if (!exynos_gem_obj)
-                return;
-
         obj = &exynos_gem_obj->base;
+        buf = exynos_gem_obj->buffer;
 
         DRM_DEBUG_KMS("handle count = %d\n", atomic_read(&obj->handle_count));
 
-        if ((exynos_gem_obj->flags & EXYNOS_BO_NONCONTIG) &&
-                        exynos_gem_obj->buffer->pages)
+        if (!buf->pages)
+                return;
+
+        if (exynos_gem_obj->flags & EXYNOS_BO_NONCONTIG)
                 exynos_drm_gem_put_pages(obj);
         else
-                exynos_drm_free_buf(obj->dev, exynos_gem_obj->flags,
-                                        exynos_gem_obj->buffer);
+                exynos_drm_free_buf(obj->dev, exynos_gem_obj->flags, buf);
 
-        exynos_drm_fini_buf(obj->dev, exynos_gem_obj->buffer);
+        exynos_drm_fini_buf(obj->dev, buf);
         exynos_gem_obj->buffer = NULL;
 
         if (obj->map_list.map)
@@ -493,8 +509,7 @@ static int exynos_drm_gem_mmap_buffer(struct file *filp,
 
         vma->vm_flags |= (VM_IO | VM_RESERVED);
 
-        /* in case of direct mapping, always having non-cachable attribute */
-        vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
+        update_vm_cache_attr(exynos_gem_obj, vma);
 
         vm_size = usize = vma->vm_end - vma->vm_start;
 
@@ -724,6 +739,8 @@ int exynos_drm_gem_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 
 int exynos_drm_gem_mmap(struct file *filp, struct vm_area_struct *vma)
 {
+        struct exynos_drm_gem_obj *exynos_gem_obj;
+        struct drm_gem_object *obj;
         int ret;
 
         DRM_DEBUG_KMS("%s\n", __FILE__);
@@ -735,8 +752,20 @@ int exynos_drm_gem_mmap(struct file *filp, struct vm_area_struct *vma)
                 return ret;
         }
 
+        obj = vma->vm_private_data;
+        exynos_gem_obj = to_exynos_gem_obj(obj);
+
+        ret = check_gem_flags(exynos_gem_obj->flags);
+        if (ret) {
+                drm_gem_vm_close(vma);
+                drm_gem_free_mmap_offset(obj);
+                return ret;
+        }
+
         vma->vm_flags &= ~VM_PFNMAP;
         vma->vm_flags |= VM_MIXEDMAP;
 
+        update_vm_cache_attr(exynos_gem_obj, vma);
+
         return ret;
 }