On 3/3/22 21:58, Thomas Zimmermann wrote:
Implement struct drm_driver.dumb_create_fbdev for GEM SHMEM. The created buffer object returned by this function implements deferred I/O for its mmap operation.
Add this feature to a number of drivers that use GEM SHMEM helpers as shadow planes over their regular video memory. The new macro DRM_GEM_SHMEM_DRIVER_OPS_WITH_SHADOW_PLANES sets the regular GEM functions and dumb_create_fbdev in struct drm_driver. Fbdev emulation on these drivers will now mmap the GEM SHMEM pages directly with deferred I/O without an intermediate shadow buffer.
Signed-off-by: Thomas Zimmermann tzimmermann@suse.de
[snip]
@@ -49,8 +50,20 @@ static const struct drm_gem_object_funcs drm_gem_shmem_funcs = { .vm_ops = &drm_gem_shmem_vm_ops, };
+static const struct drm_gem_object_funcs drm_gem_shmem_funcs_fbdev = {
- .free = drm_gem_shmem_object_free,
- .print_info = drm_gem_shmem_object_print_info,
- .pin = drm_gem_shmem_object_pin,
- .unpin = drm_gem_shmem_object_unpin,
- .get_sg_table = drm_gem_shmem_object_get_sg_table,
- .vmap = drm_gem_shmem_object_vmap,
- .vunmap = drm_gem_shmem_object_vunmap,
- .mmap = drm_gem_shmem_object_mmap_fbdev,
- .vm_ops = &drm_gem_shmem_vm_ops_fbdev,
The drm_gem_shmem_funcs_fbdev is the same than drm_gem_shmem_funcs but .mmap and .vm_ops callbacks. Maybe adding a macro to declare these two struct drm_gem_object_funcs could make easier to maintain it long term ?
+};
static struct drm_gem_shmem_object * -__drm_gem_shmem_create(struct drm_device *dev, size_t size, bool private) +__drm_gem_shmem_create(struct drm_device *dev, size_t size, bool private, bool fbdev) { struct drm_gem_shmem_object *shmem; struct drm_gem_object *obj; @@ -70,8 +83,12 @@ __drm_gem_shmem_create(struct drm_device *dev, size_t size, bool private) obj = &shmem->base; }
- if (!obj->funcs)
obj->funcs = &drm_gem_shmem_funcs;
- if (!obj->funcs) {
if (fbdev)
Same question than in patch #6, maybe
if (defined(CONFIG_DRM_FBDEV_EMULATION) && fbdev) ?
[snip]
- */
+int drm_gem_shmem_dumb_create_fbdev(struct drm_file *file, struct drm_device *dev,
struct drm_mode_create_dumb *args)+{ +#if defined(CONFIG_DRM_FBDEV_EMULATION)
- return __drm_gem_shmem_dumb_create(file, dev, true, args);
+#else
- return -ENOSYS;
+#endif +}
I believe the correct errno code here should be -ENOTSUPP.
[snip]
- /* We don't use vmf->pgoff since that has the fake offset */
- page_offset = (vmf->address - vma->vm_start) >> PAGE_SHIFT;
I see this (vmf->address - vma->vm_start) calculation in many places of this series. Maybe we could add a macro to calculate the offset instead ?
Reviewed-by: Javier Martinez Canillas javierm@redhat.com