Add a library for drivers that can use a simple representation of a GEM backed framebuffer.
Signed-off-by: Noralf Trønnes noralf@tronnes.org --- drivers/gpu/drm/Makefile | 2 +- drivers/gpu/drm/drm_fb_gem_helper.c | 248 ++++++++++++++++++++++++++++++++++++ include/drm/drm_fb_gem_helper.h | 64 ++++++++++ 3 files changed, 313 insertions(+), 1 deletion(-) create mode 100644 drivers/gpu/drm/drm_fb_gem_helper.c create mode 100644 include/drm/drm_fb_gem_helper.h
diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile index 24a066e..83d8b09 100644 --- a/drivers/gpu/drm/Makefile +++ b/drivers/gpu/drm/Makefile @@ -33,7 +33,7 @@ drm_kms_helper-y := drm_crtc_helper.o drm_dp_helper.o drm_probe_helper.o \ drm_plane_helper.o drm_dp_mst_topology.o drm_atomic_helper.o \ drm_kms_helper_common.o drm_dp_dual_mode_helper.o \ drm_simple_kms_helper.o drm_modeset_helper.o \ - drm_scdc_helper.o + drm_scdc_helper.o drm_fb_gem_helper.o
drm_kms_helper-$(CONFIG_DRM_PANEL_BRIDGE) += bridge/panel.o drm_kms_helper-$(CONFIG_DRM_LOAD_EDID_FIRMWARE) += drm_edid_load.o diff --git a/drivers/gpu/drm/drm_fb_gem_helper.c b/drivers/gpu/drm/drm_fb_gem_helper.c new file mode 100644 index 0000000..9a0da09 --- /dev/null +++ b/drivers/gpu/drm/drm_fb_gem_helper.c @@ -0,0 +1,248 @@ +/* + * drm fb gem 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-mapping.h> +#include <linux/module.h> +#include <linux/reservation.h> + +#include <drm/drmP.h> +#include <drm/drm_atomic.h> +#include <drm/drm_crtc.h> +#include <drm/drm_crtc_helper.h> +#include <drm/drm_fb_helper.h> +#include <drm/drm_fb_gem_helper.h> +#include <drm/drm_gem.h> + +/** + * drm_fb_gem_get_obj() - Get GEM object for framebuffer + * @fb: The framebuffer + * @plane: Which plane + * + * Returns the GEM object for given framebuffer. + */ +struct drm_gem_object *drm_fb_gem_get_obj(struct drm_framebuffer *fb, + unsigned int plane) +{ + struct drm_fb_gem *fb_gem = to_fb_gem(fb); + + if (plane >= 4) + return NULL; + + return fb_gem->obj[plane]; +} +EXPORT_SYMBOL_GPL(drm_fb_gem_get_obj); + +/** + * drm_fb_gem_alloc - Allocate GEM backed framebuffer + * @dev: DRM device + * @mode_cmd: metadata from the userspace fb creation request + * @obj: GEM object nacking the framebuffer + * @num_planes: Number of planes + * @funcs: vtable to be used for the new framebuffer object + * + * Returns: + * Allocated struct drm_fb_gem * or error encoded pointer. + */ +struct drm_fb_gem * +drm_fb_gem_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_fb_gem *fb_gem; + int ret, i; + + fb_gem = kzalloc(sizeof(*fb_gem), GFP_KERNEL); + if (!fb_gem) + return ERR_PTR(-ENOMEM); + + drm_helper_mode_fill_fb_struct(dev, &fb_gem->base, mode_cmd); + + for (i = 0; i < num_planes; i++) + fb_gem->obj[i] = obj[i]; + + ret = drm_framebuffer_init(dev, &fb_gem->base, funcs); + if (ret) { + dev_err(dev->dev, "Failed to initialize framebuffer: %d\n", ret); + kfree(fb_gem); + return ERR_PTR(ret); + } + + return fb_gem; +} +EXPORT_SYMBOL(drm_fb_gem_alloc); + +/** + * drm_fb_gem_destroy - Free GEM backed framebuffer + * @fb: DRM framebuffer + * + * Frees a GEM backed framebuffer with it's backing buffer(s) and the structure + * itself. Drivers can use this as their &drm_framebuffer_funcs->destroy + * callback. + */ +void drm_fb_gem_destroy(struct drm_framebuffer *fb) +{ + struct drm_fb_gem *fb_gem = to_fb_gem(fb); + int i; + + for (i = 0; i < 4; i++) { + if (fb_gem->obj[i]) + drm_gem_object_put_unlocked(fb_gem->obj[i]); + } + + drm_framebuffer_cleanup(fb); + kfree(fb_gem); +} +EXPORT_SYMBOL(drm_fb_gem_destroy); + +/** + * drm_fb_gem_create_handle - Create handle for GEM backed framebuffer + * @fb: DRM framebuffer + * @file: drm file + * @handle: handle created + * + * Drivers can use this as their &drm_framebuffer_funcs->create_handle + * callback. + * + * Returns: + * 0 on success or a negative error code on failure. + */ +int drm_fb_gem_create_handle(struct drm_framebuffer *fb, struct drm_file *file, + unsigned int *handle) +{ + struct drm_fb_gem *fb_gem = to_fb_gem(fb); + + return drm_gem_handle_create(file, fb_gem->obj[0], handle); +} +EXPORT_SYMBOL(drm_fb_gem_create_handle); + +/** + * drm_fb_gem_create_with_funcs() - helper function for the + * &drm_mode_config_funcs.fb_create + * callback + * @dev: DRM device + * @file: drm file for the ioctl call + * @mode_cmd: metadata from the userspace fb 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_fb_gem_create() if you don't + * need to change &drm_framebuffer_funcs. + */ +struct drm_framebuffer * +drm_fb_gem_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_fb_gem *fb_gem; + 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]) { + dev_err(dev->dev, "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_gem = drm_fb_gem_alloc(dev, mode_cmd, objs, i, funcs); + if (IS_ERR(fb_gem)) { + ret = PTR_ERR(fb_gem); + goto err_gem_object_put; + } + + return &fb_gem->base; + +err_gem_object_put: + for (i--; i >= 0; i--) + drm_gem_object_put_unlocked(objs[i]); + + return ERR_PTR(ret); +} +EXPORT_SYMBOL_GPL(drm_fb_gem_create_with_funcs); + +static struct drm_framebuffer_funcs drm_fb_gem_fb_funcs = { + .destroy = drm_fb_gem_destroy, + .create_handle = drm_fb_gem_create_handle, +}; + +/** + * drm_fb_gem_create() - &drm_mode_config_funcs.fb_create callback function + * @dev: DRM device + * @file: drm file for the ioctl call + * @mode_cmd: metadata from the userspace fb creation request + * + * If your hardware has special alignment or pitch requirements these should be + * checked before calling this function. Use drm_fb_gem_create_with_funcs() if + * you need to set &drm_framebuffer_funcs.dirty. + */ +struct drm_framebuffer * +drm_fb_gem_create(struct drm_device *dev, struct drm_file *file, + const struct drm_mode_fb_cmd2 *mode_cmd) +{ + return drm_fb_gem_create_with_funcs(dev, file, mode_cmd, + &drm_fb_gem_fb_funcs); +} +EXPORT_SYMBOL_GPL(drm_fb_gem_create); + +/** + * drm_fb_gem_prepare_fb() - Prepare gem framebuffer + * @plane: Which plane + * @state: Plane state attach fence to + * + * This should be set as the &struct drm_plane_helper_funcs.prepare_fb hook. + * + * This function checks if the plane FB has an dma-buf attached, extracts + * the exclusive fence and attaches it to plane state for the atomic helper + * to wait on. + * + * There is no need for cleanup_fb for gem based framebuffer drivers. + */ +int drm_fb_gem_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_fb_gem_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_fb_gem_prepare_fb); diff --git a/include/drm/drm_fb_gem_helper.h b/include/drm/drm_fb_gem_helper.h new file mode 100644 index 0000000..405a1e1 --- /dev/null +++ b/include/drm/drm_fb_gem_helper.h @@ -0,0 +1,64 @@ +#ifndef __DRM_FB_GEM_HELPER_H__ +#define __DRM_FB_GEM_HELPER_H__ + +#include <drm/drm_framebuffer.h> + +struct drm_gem_shmem_object; +struct drm_mode_fb_cmd2; +struct drm_plane; +struct drm_plane_state; + +/** + * struct drm_fb_gem - GEM backed framebuffer + */ +struct drm_fb_gem { + /** + * @base: Base DRM framebuffer + */ + struct drm_framebuffer base; + /** + * @obj: GEM object array backing the framebuffer. One object per + * plane. + */ + struct drm_gem_object *obj[4]; +}; + +static inline struct drm_fb_gem *to_fb_gem(struct drm_framebuffer *fb) +{ + return container_of(fb, struct drm_fb_gem, base); +} + +struct drm_gem_object *drm_fb_gem_get_obj(struct drm_framebuffer *fb, + unsigned int plane); +struct drm_fb_gem * +drm_fb_gem_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); +void drm_fb_gem_destroy(struct drm_framebuffer *fb); +int drm_fb_gem_create_handle(struct drm_framebuffer *fb, struct drm_file *file, + unsigned int *handle); + +struct drm_framebuffer * +drm_fb_gem_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); +struct drm_framebuffer * +drm_fb_gem_create(struct drm_device *dev, struct drm_file *file, + const struct drm_mode_fb_cmd2 *mode_cmd); + + +int drm_fb_gem_prepare_fb(struct drm_plane *plane, + struct drm_plane_state *state); + + + + +#ifdef CONFIG_DEBUG_FS +struct seq_file; + +int drm_fb_gem_debugfs_show(struct seq_file *m, void *arg); +#endif + +#endif +