| /* |
| * drm gem framebuffer helper functions |
| * |
| * Copyright (C) 2017 Noralf Trønnes |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; either version 2 of the License, or |
| * (at your option) any later version. |
| */ |
| |
| #include <linux/dma-buf.h> |
| #include <linux/dma-fence.h> |
| #include <linux/reservation.h> |
| #include <linux/slab.h> |
| |
| #include <drm/drmP.h> |
| #include <drm/drm_atomic.h> |
| #include <drm/drm_fb_helper.h> |
| #include <drm/drm_fourcc.h> |
| #include <drm/drm_framebuffer.h> |
| #include <drm/drm_gem.h> |
| #include <drm/drm_gem_framebuffer_helper.h> |
| #include <drm/drm_modeset_helper.h> |
| |
| /** |
| * DOC: overview |
| * |
| * This library provides helpers for drivers that don't subclass |
| * &drm_framebuffer and use &drm_gem_object for their backing storage. |
| * |
| * Drivers without additional needs to validate framebuffers can simply use |
| * drm_gem_fb_create() and everything is wired up automatically. Other drivers |
| * can use all parts independently. |
| */ |
| |
| /** |
| * drm_gem_fb_get_obj() - Get GEM object backing the framebuffer |
| * @fb: Framebuffer |
| * @plane: Plane index |
| * |
| * No additional reference is taken beyond the one that the &drm_frambuffer |
| * already holds. |
| * |
| * Returns: |
| * Pointer to &drm_gem_object for the given framebuffer and plane index or NULL |
| * if it does not exist. |
| */ |
| struct drm_gem_object *drm_gem_fb_get_obj(struct drm_framebuffer *fb, |
| unsigned int plane) |
| { |
| if (plane >= 4) |
| return NULL; |
| |
| return fb->obj[plane]; |
| } |
| EXPORT_SYMBOL_GPL(drm_gem_fb_get_obj); |
| |
| static struct drm_framebuffer * |
| drm_gem_fb_alloc(struct drm_device *dev, |
| const struct drm_mode_fb_cmd2 *mode_cmd, |
| struct drm_gem_object **obj, unsigned int num_planes, |
| const struct drm_framebuffer_funcs *funcs) |
| { |
| struct drm_framebuffer *fb; |
| int ret, i; |
| |
| fb = kzalloc(sizeof(*fb), GFP_KERNEL); |
| if (!fb) |
| return ERR_PTR(-ENOMEM); |
| |
| drm_helper_mode_fill_fb_struct(dev, fb, mode_cmd); |
| |
| for (i = 0; i < num_planes; i++) |
| fb->obj[i] = obj[i]; |
| |
| ret = drm_framebuffer_init(dev, fb, funcs); |
| if (ret) { |
| DRM_DEV_ERROR(dev->dev, "Failed to init framebuffer: %d\n", |
| ret); |
| kfree(fb); |
| return ERR_PTR(ret); |
| } |
| |
| return fb; |
| } |
| |
| /** |
| * drm_gem_fb_destroy - Free GEM backed framebuffer |
| * @fb: Framebuffer |
| * |
| * Frees a GEM backed framebuffer with its backing buffer(s) and the structure |
| * itself. Drivers can use this as their &drm_framebuffer_funcs->destroy |
| * callback. |
| */ |
| void drm_gem_fb_destroy(struct drm_framebuffer *fb) |
| { |
| int i; |
| |
| for (i = 0; i < 4; i++) |
| drm_gem_object_put_unlocked(fb->obj[i]); |
| |
| drm_framebuffer_cleanup(fb); |
| kfree(fb); |
| } |
| EXPORT_SYMBOL(drm_gem_fb_destroy); |
| |
| /** |
| * drm_gem_fb_create_handle - Create handle for GEM backed framebuffer |
| * @fb: Framebuffer |
| * @file: DRM file to register the handle for |
| * @handle: Pointer to return the created handle |
| * |
| * This function creates a handle for the GEM object backing the framebuffer. |
| * Drivers can use this as their &drm_framebuffer_funcs->create_handle |
| * callback. The GETFB IOCTL calls into this callback. |
| * |
| * Returns: |
| * 0 on success or a negative error code on failure. |
| */ |
| int drm_gem_fb_create_handle(struct drm_framebuffer *fb, struct drm_file *file, |
| unsigned int *handle) |
| { |
| return drm_gem_handle_create(file, fb->obj[0], handle); |
| } |
| EXPORT_SYMBOL(drm_gem_fb_create_handle); |
| |
| /** |
| * drm_gem_fb_create_with_funcs() - Helper function for the |
| * &drm_mode_config_funcs.fb_create |
| * callback |
| * @dev: DRM device |
| * @file: DRM file that holds the GEM handle(s) backing the framebuffer |
| * @mode_cmd: Metadata from the userspace framebuffer creation request |
| * @funcs: vtable to be used for the new framebuffer object |
| * |
| * This can be used to set &drm_framebuffer_funcs for drivers that need the |
| * &drm_framebuffer_funcs.dirty callback. Use drm_gem_fb_create() if you don't |
| * need to change &drm_framebuffer_funcs. |
| * The function does buffer size validation. |
| * |
| * Returns: |
| * Pointer to a &drm_framebuffer on success or an error pointer on failure. |
| */ |
| struct drm_framebuffer * |
| drm_gem_fb_create_with_funcs(struct drm_device *dev, struct drm_file *file, |
| const struct drm_mode_fb_cmd2 *mode_cmd, |
| const struct drm_framebuffer_funcs *funcs) |
| { |
| const struct drm_format_info *info; |
| struct drm_gem_object *objs[4]; |
| struct drm_framebuffer *fb; |
| int ret, i; |
| |
| info = drm_get_format_info(dev, mode_cmd); |
| if (!info) |
| return ERR_PTR(-EINVAL); |
| |
| for (i = 0; i < info->num_planes; i++) { |
| unsigned int width = mode_cmd->width / (i ? info->hsub : 1); |
| unsigned int height = mode_cmd->height / (i ? info->vsub : 1); |
| unsigned int min_size; |
| |
| objs[i] = drm_gem_object_lookup(file, mode_cmd->handles[i]); |
| if (!objs[i]) { |
| DRM_DEBUG_KMS("Failed to lookup GEM object\n"); |
| ret = -ENOENT; |
| goto err_gem_object_put; |
| } |
| |
| min_size = (height - 1) * mode_cmd->pitches[i] |
| + width * info->cpp[i] |
| + mode_cmd->offsets[i]; |
| |
| if (objs[i]->size < min_size) { |
| drm_gem_object_put_unlocked(objs[i]); |
| ret = -EINVAL; |
| goto err_gem_object_put; |
| } |
| } |
| |
| fb = drm_gem_fb_alloc(dev, mode_cmd, objs, i, funcs); |
| if (IS_ERR(fb)) { |
| ret = PTR_ERR(fb); |
| goto err_gem_object_put; |
| } |
| |
| return fb; |
| |
| err_gem_object_put: |
| for (i--; i >= 0; i--) |
| drm_gem_object_put_unlocked(objs[i]); |
| |
| return ERR_PTR(ret); |
| } |
| EXPORT_SYMBOL_GPL(drm_gem_fb_create_with_funcs); |
| |
| static const struct drm_framebuffer_funcs drm_gem_fb_funcs = { |
| .destroy = drm_gem_fb_destroy, |
| .create_handle = drm_gem_fb_create_handle, |
| }; |
| |
| /** |
| * drm_gem_fb_create() - Helper function for the |
| * &drm_mode_config_funcs.fb_create callback |
| * @dev: DRM device |
| * @file: DRM file that holds the GEM handle(s) backing the framebuffer |
| * @mode_cmd: Metadata from the userspace framebuffer creation request |
| * |
| * This function creates a new framebuffer object described by |
| * &drm_mode_fb_cmd2. This description includes handles for the buffer(s) |
| * backing the framebuffer. |
| * |
| * If your hardware has special alignment or pitch requirements these should be |
| * checked before calling this function. The function does buffer size |
| * validation. Use drm_gem_fb_create_with_funcs() if you need to set |
| * &drm_framebuffer_funcs.dirty. |
| * |
| * Drivers can use this as their &drm_mode_config_funcs.fb_create callback. |
| * The ADDFB2 IOCTL calls into this callback. |
| * |
| * Returns: |
| * Pointer to a &drm_framebuffer on success or an error pointer on failure. |
| */ |
| struct drm_framebuffer * |
| drm_gem_fb_create(struct drm_device *dev, struct drm_file *file, |
| const struct drm_mode_fb_cmd2 *mode_cmd) |
| { |
| return drm_gem_fb_create_with_funcs(dev, file, mode_cmd, |
| &drm_gem_fb_funcs); |
| } |
| EXPORT_SYMBOL_GPL(drm_gem_fb_create); |
| |
| /** |
| * drm_gem_fb_prepare_fb() - Prepare a GEM backed framebuffer |
| * @plane: Plane |
| * @state: Plane state the fence will be attached to |
| * |
| * This function prepares a GEM backed framebuffer for scanout by checking if |
| * the plane framebuffer has a DMA-BUF attached. If it does, it extracts the |
| * exclusive fence and attaches it to the plane state for the atomic helper to |
| * wait on. This function can be used as the &drm_plane_helper_funcs.prepare_fb |
| * callback. |
| * |
| * There is no need for &drm_plane_helper_funcs.cleanup_fb hook for simple |
| * gem based framebuffer drivers which have their buffers always pinned in |
| * memory. |
| */ |
| int drm_gem_fb_prepare_fb(struct drm_plane *plane, |
| struct drm_plane_state *state) |
| { |
| struct dma_buf *dma_buf; |
| struct dma_fence *fence; |
| |
| if (plane->state->fb == state->fb || !state->fb) |
| return 0; |
| |
| dma_buf = drm_gem_fb_get_obj(state->fb, 0)->dma_buf; |
| if (dma_buf) { |
| fence = reservation_object_get_excl_rcu(dma_buf->resv); |
| drm_atomic_set_fence_for_plane(state, fence); |
| } |
| |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(drm_gem_fb_prepare_fb); |
| |
| /** |
| * drm_gem_fbdev_fb_create - Create a GEM backed &drm_framebuffer for fbdev |
| * emulation |
| * @dev: DRM device |
| * @sizes: fbdev size description |
| * @pitch_align: Optional pitch alignment |
| * @obj: GEM object backing the framebuffer |
| * @funcs: vtable to be used for the new framebuffer object |
| * |
| * This function creates a framebuffer from a &drm_fb_helper_surface_size |
| * description for use in the &drm_fb_helper_funcs.fb_probe callback. |
| * |
| * Returns: |
| * Pointer to a &drm_framebuffer on success or an error pointer on failure. |
| */ |
| struct drm_framebuffer * |
| drm_gem_fbdev_fb_create(struct drm_device *dev, |
| struct drm_fb_helper_surface_size *sizes, |
| unsigned int pitch_align, struct drm_gem_object *obj, |
| const struct drm_framebuffer_funcs *funcs) |
| { |
| struct drm_mode_fb_cmd2 mode_cmd = { 0 }; |
| |
| mode_cmd.width = sizes->surface_width; |
| mode_cmd.height = sizes->surface_height; |
| mode_cmd.pitches[0] = sizes->surface_width * |
| DIV_ROUND_UP(sizes->surface_bpp, 8); |
| if (pitch_align) |
| mode_cmd.pitches[0] = roundup(mode_cmd.pitches[0], |
| pitch_align); |
| mode_cmd.pixel_format = drm_mode_legacy_fb_format(sizes->surface_bpp, |
| sizes->surface_depth); |
| if (obj->size < mode_cmd.pitches[0] * mode_cmd.height) |
| return ERR_PTR(-EINVAL); |
| |
| return drm_gem_fb_alloc(dev, &mode_cmd, &obj, 1, funcs); |
| } |
| EXPORT_SYMBOL(drm_gem_fbdev_fb_create); |