diff options
Diffstat (limited to 'drivers/gpu/drm/drm_client.c')
| -rw-r--r-- | drivers/gpu/drm/drm_client.c | 543 |
1 files changed, 543 insertions, 0 deletions
diff --git a/drivers/gpu/drm/drm_client.c b/drivers/gpu/drm/drm_client.c new file mode 100644 index 0000000000..037e36f204 --- /dev/null +++ b/drivers/gpu/drm/drm_client.c @@ -0,0 +1,543 @@ +// SPDX-License-Identifier: GPL-2.0 or MIT +/* + * Copyright 2018 Noralf Trønnes + */ + +#include <linux/iosys-map.h> +#include <linux/list.h> +#include <linux/module.h> +#include <linux/mutex.h> +#include <linux/seq_file.h> +#include <linux/slab.h> + +#include <drm/drm_client.h> +#include <drm/drm_debugfs.h> +#include <drm/drm_device.h> +#include <drm/drm_drv.h> +#include <drm/drm_file.h> +#include <drm/drm_fourcc.h> +#include <drm/drm_framebuffer.h> +#include <drm/drm_gem.h> +#include <drm/drm_mode.h> +#include <drm/drm_print.h> + +#include "drm_crtc_internal.h" +#include "drm_internal.h" + +/** + * DOC: overview + * + * This library provides support for clients running in the kernel like fbdev and bootsplash. + * + * GEM drivers which provide a GEM based dumb buffer with a virtual address are supported. + */ + +static int drm_client_open(struct drm_client_dev *client) +{ + struct drm_device *dev = client->dev; + struct drm_file *file; + + file = drm_file_alloc(dev->primary); + if (IS_ERR(file)) + return PTR_ERR(file); + + mutex_lock(&dev->filelist_mutex); + list_add(&file->lhead, &dev->filelist_internal); + mutex_unlock(&dev->filelist_mutex); + + client->file = file; + + return 0; +} + +static void drm_client_close(struct drm_client_dev *client) +{ + struct drm_device *dev = client->dev; + + mutex_lock(&dev->filelist_mutex); + list_del(&client->file->lhead); + mutex_unlock(&dev->filelist_mutex); + + drm_file_free(client->file); +} + +/** + * drm_client_init - Initialise a DRM client + * @dev: DRM device + * @client: DRM client + * @name: Client name + * @funcs: DRM client functions (optional) + * + * This initialises the client and opens a &drm_file. + * Use drm_client_register() to complete the process. + * The caller needs to hold a reference on @dev before calling this function. + * The client is freed when the &drm_device is unregistered. See drm_client_release(). + * + * Returns: + * Zero on success or negative error code on failure. + */ +int drm_client_init(struct drm_device *dev, struct drm_client_dev *client, + const char *name, const struct drm_client_funcs *funcs) +{ + int ret; + + if (!drm_core_check_feature(dev, DRIVER_MODESET) || !dev->driver->dumb_create) + return -EOPNOTSUPP; + + if (funcs && !try_module_get(funcs->owner)) + return -ENODEV; + + client->dev = dev; + client->name = name; + client->funcs = funcs; + + ret = drm_client_modeset_create(client); + if (ret) + goto err_put_module; + + ret = drm_client_open(client); + if (ret) + goto err_free; + + drm_dev_get(dev); + + return 0; + +err_free: + drm_client_modeset_free(client); +err_put_module: + if (funcs) + module_put(funcs->owner); + + return ret; +} +EXPORT_SYMBOL(drm_client_init); + +/** + * drm_client_register - Register client + * @client: DRM client + * + * Add the client to the &drm_device client list to activate its callbacks. + * @client must be initialized by a call to drm_client_init(). After + * drm_client_register() it is no longer permissible to call drm_client_release() + * directly (outside the unregister callback), instead cleanup will happen + * automatically on driver unload. + * + * Registering a client generates a hotplug event that allows the client + * to set up its display from pre-existing outputs. The client must have + * initialized its state to able to handle the hotplug event successfully. + */ +void drm_client_register(struct drm_client_dev *client) +{ + struct drm_device *dev = client->dev; + int ret; + + mutex_lock(&dev->clientlist_mutex); + list_add(&client->list, &dev->clientlist); + + if (client->funcs && client->funcs->hotplug) { + /* + * Perform an initial hotplug event to pick up the + * display configuration for the client. This step + * has to be performed *after* registering the client + * in the list of clients, or a concurrent hotplug + * event might be lost; leaving the display off. + * + * Hold the clientlist_mutex as for a regular hotplug + * event. + */ + ret = client->funcs->hotplug(client); + if (ret) + drm_dbg_kms(dev, "client hotplug ret=%d\n", ret); + } + mutex_unlock(&dev->clientlist_mutex); +} +EXPORT_SYMBOL(drm_client_register); + +/** + * drm_client_release - Release DRM client resources + * @client: DRM client + * + * Releases resources by closing the &drm_file that was opened by drm_client_init(). + * It is called automatically if the &drm_client_funcs.unregister callback is _not_ set. + * + * This function should only be called from the unregister callback. An exception + * is fbdev which cannot free the buffer if userspace has open file descriptors. + * + * Note: + * Clients cannot initiate a release by themselves. This is done to keep the code simple. + * The driver has to be unloaded before the client can be unloaded. + */ +void drm_client_release(struct drm_client_dev *client) +{ + struct drm_device *dev = client->dev; + + drm_dbg_kms(dev, "%s\n", client->name); + + drm_client_modeset_free(client); + drm_client_close(client); + drm_dev_put(dev); + if (client->funcs) + module_put(client->funcs->owner); +} +EXPORT_SYMBOL(drm_client_release); + +void drm_client_dev_unregister(struct drm_device *dev) +{ + struct drm_client_dev *client, *tmp; + + if (!drm_core_check_feature(dev, DRIVER_MODESET)) + return; + + mutex_lock(&dev->clientlist_mutex); + list_for_each_entry_safe(client, tmp, &dev->clientlist, list) { + list_del(&client->list); + if (client->funcs && client->funcs->unregister) { + client->funcs->unregister(client); + } else { + drm_client_release(client); + kfree(client); + } + } + mutex_unlock(&dev->clientlist_mutex); +} + +/** + * drm_client_dev_hotplug - Send hotplug event to clients + * @dev: DRM device + * + * This function calls the &drm_client_funcs.hotplug callback on the attached clients. + * + * drm_kms_helper_hotplug_event() calls this function, so drivers that use it + * don't need to call this function themselves. + */ +void drm_client_dev_hotplug(struct drm_device *dev) +{ + struct drm_client_dev *client; + int ret; + + if (!drm_core_check_feature(dev, DRIVER_MODESET)) + return; + + if (!dev->mode_config.num_connector) { + drm_dbg_kms(dev, "No connectors found, will not send hotplug events!\n"); + return; + } + + mutex_lock(&dev->clientlist_mutex); + list_for_each_entry(client, &dev->clientlist, list) { + if (!client->funcs || !client->funcs->hotplug) + continue; + + if (client->hotplug_failed) + continue; + + ret = client->funcs->hotplug(client); + drm_dbg_kms(dev, "%s: ret=%d\n", client->name, ret); + if (ret) + client->hotplug_failed = true; + } + mutex_unlock(&dev->clientlist_mutex); +} +EXPORT_SYMBOL(drm_client_dev_hotplug); + +void drm_client_dev_restore(struct drm_device *dev) +{ + struct drm_client_dev *client; + int ret; + + if (!drm_core_check_feature(dev, DRIVER_MODESET)) + return; + + mutex_lock(&dev->clientlist_mutex); + list_for_each_entry(client, &dev->clientlist, list) { + if (!client->funcs || !client->funcs->restore) + continue; + + ret = client->funcs->restore(client); + drm_dbg_kms(dev, "%s: ret=%d\n", client->name, ret); + if (!ret) /* The first one to return zero gets the privilege to restore */ + break; + } + mutex_unlock(&dev->clientlist_mutex); +} + +static void drm_client_buffer_delete(struct drm_client_buffer *buffer) +{ + if (buffer->gem) { + drm_gem_vunmap_unlocked(buffer->gem, &buffer->map); + drm_gem_object_put(buffer->gem); + } + + kfree(buffer); +} + +static struct drm_client_buffer * +drm_client_buffer_create(struct drm_client_dev *client, u32 width, u32 height, + u32 format, u32 *handle) +{ + const struct drm_format_info *info = drm_format_info(format); + struct drm_mode_create_dumb dumb_args = { }; + struct drm_device *dev = client->dev; + struct drm_client_buffer *buffer; + struct drm_gem_object *obj; + int ret; + + buffer = kzalloc(sizeof(*buffer), GFP_KERNEL); + if (!buffer) + return ERR_PTR(-ENOMEM); + + buffer->client = client; + + dumb_args.width = width; + dumb_args.height = height; + dumb_args.bpp = drm_format_info_bpp(info, 0); + ret = drm_mode_create_dumb(dev, &dumb_args, client->file); + if (ret) + goto err_delete; + + obj = drm_gem_object_lookup(client->file, dumb_args.handle); + if (!obj) { + ret = -ENOENT; + goto err_delete; + } + + buffer->pitch = dumb_args.pitch; + buffer->gem = obj; + *handle = dumb_args.handle; + + return buffer; + +err_delete: + drm_client_buffer_delete(buffer); + + return ERR_PTR(ret); +} + +/** + * drm_client_buffer_vmap - Map DRM client buffer into address space + * @buffer: DRM client buffer + * @map_copy: Returns the mapped memory's address + * + * This function maps a client buffer into kernel address space. If the + * buffer is already mapped, it returns the existing mapping's address. + * + * Client buffer mappings are not ref'counted. Each call to + * drm_client_buffer_vmap() should be followed by a call to + * drm_client_buffer_vunmap(); or the client buffer should be mapped + * throughout its lifetime. + * + * The returned address is a copy of the internal value. In contrast to + * other vmap interfaces, you don't need it for the client's vunmap + * function. So you can modify it at will during blit and draw operations. + * + * Returns: + * 0 on success, or a negative errno code otherwise. + */ +int +drm_client_buffer_vmap(struct drm_client_buffer *buffer, + struct iosys_map *map_copy) +{ + struct iosys_map *map = &buffer->map; + int ret; + + /* + * FIXME: The dependency on GEM here isn't required, we could + * convert the driver handle to a dma-buf instead and use the + * backend-agnostic dma-buf vmap support instead. This would + * require that the handle2fd prime ioctl is reworked to pull the + * fd_install step out of the driver backend hooks, to make that + * final step optional for internal users. + */ + ret = drm_gem_vmap_unlocked(buffer->gem, map); + if (ret) + return ret; + + *map_copy = *map; + + return 0; +} +EXPORT_SYMBOL(drm_client_buffer_vmap); + +/** + * drm_client_buffer_vunmap - Unmap DRM client buffer + * @buffer: DRM client buffer + * + * This function removes a client buffer's memory mapping. Calling this + * function is only required by clients that manage their buffer mappings + * by themselves. + */ +void drm_client_buffer_vunmap(struct drm_client_buffer *buffer) +{ + struct iosys_map *map = &buffer->map; + + drm_gem_vunmap_unlocked(buffer->gem, map); +} +EXPORT_SYMBOL(drm_client_buffer_vunmap); + +static void drm_client_buffer_rmfb(struct drm_client_buffer *buffer) +{ + int ret; + + if (!buffer->fb) + return; + + ret = drm_mode_rmfb(buffer->client->dev, buffer->fb->base.id, buffer->client->file); + if (ret) + drm_err(buffer->client->dev, + "Error removing FB:%u (%d)\n", buffer->fb->base.id, ret); + + buffer->fb = NULL; +} + +static int drm_client_buffer_addfb(struct drm_client_buffer *buffer, + u32 width, u32 height, u32 format, + u32 handle) +{ + struct drm_client_dev *client = buffer->client; + struct drm_mode_fb_cmd fb_req = { }; + const struct drm_format_info *info; + int ret; + + info = drm_format_info(format); + fb_req.bpp = drm_format_info_bpp(info, 0); + fb_req.depth = info->depth; + fb_req.width = width; + fb_req.height = height; + fb_req.handle = handle; + fb_req.pitch = buffer->pitch; + + ret = drm_mode_addfb(client->dev, &fb_req, client->file); + if (ret) + return ret; + + buffer->fb = drm_framebuffer_lookup(client->dev, buffer->client->file, fb_req.fb_id); + if (WARN_ON(!buffer->fb)) + return -ENOENT; + + /* drop the reference we picked up in framebuffer lookup */ + drm_framebuffer_put(buffer->fb); + + strscpy(buffer->fb->comm, client->name, TASK_COMM_LEN); + + return 0; +} + +/** + * drm_client_framebuffer_create - Create a client framebuffer + * @client: DRM client + * @width: Framebuffer width + * @height: Framebuffer height + * @format: Buffer format + * + * This function creates a &drm_client_buffer which consists of a + * &drm_framebuffer backed by a dumb buffer. + * Call drm_client_framebuffer_delete() to free the buffer. + * + * Returns: + * Pointer to a client buffer or an error pointer on failure. + */ +struct drm_client_buffer * +drm_client_framebuffer_create(struct drm_client_dev *client, u32 width, u32 height, u32 format) +{ + struct drm_client_buffer *buffer; + u32 handle; + int ret; + + buffer = drm_client_buffer_create(client, width, height, format, + &handle); + if (IS_ERR(buffer)) + return buffer; + + ret = drm_client_buffer_addfb(buffer, width, height, format, handle); + + /* + * The handle is only needed for creating the framebuffer, destroy it + * again to solve a circular dependency should anybody export the GEM + * object as DMA-buf. The framebuffer and our buffer structure are still + * holding references to the GEM object to prevent its destruction. + */ + drm_mode_destroy_dumb(client->dev, handle, client->file); + + if (ret) { + drm_client_buffer_delete(buffer); + return ERR_PTR(ret); + } + + return buffer; +} +EXPORT_SYMBOL(drm_client_framebuffer_create); + +/** + * drm_client_framebuffer_delete - Delete a client framebuffer + * @buffer: DRM client buffer (can be NULL) + */ +void drm_client_framebuffer_delete(struct drm_client_buffer *buffer) +{ + if (!buffer) + return; + + drm_client_buffer_rmfb(buffer); + drm_client_buffer_delete(buffer); +} +EXPORT_SYMBOL(drm_client_framebuffer_delete); + +/** + * drm_client_framebuffer_flush - Manually flush client framebuffer + * @buffer: DRM client buffer (can be NULL) + * @rect: Damage rectangle (if NULL flushes all) + * + * This calls &drm_framebuffer_funcs->dirty (if present) to flush buffer changes + * for drivers that need it. + * + * Returns: + * Zero on success or negative error code on failure. + */ +int drm_client_framebuffer_flush(struct drm_client_buffer *buffer, struct drm_rect *rect) +{ + if (!buffer || !buffer->fb || !buffer->fb->funcs->dirty) + return 0; + + if (rect) { + struct drm_clip_rect clip = { + .x1 = rect->x1, + .y1 = rect->y1, + .x2 = rect->x2, + .y2 = rect->y2, + }; + + return buffer->fb->funcs->dirty(buffer->fb, buffer->client->file, + 0, 0, &clip, 1); + } + + return buffer->fb->funcs->dirty(buffer->fb, buffer->client->file, + 0, 0, NULL, 0); +} +EXPORT_SYMBOL(drm_client_framebuffer_flush); + +#ifdef CONFIG_DEBUG_FS +static int drm_client_debugfs_internal_clients(struct seq_file *m, void *data) +{ + struct drm_debugfs_entry *entry = m->private; + struct drm_device *dev = entry->dev; + struct drm_printer p = drm_seq_file_printer(m); + struct drm_client_dev *client; + + mutex_lock(&dev->clientlist_mutex); + list_for_each_entry(client, &dev->clientlist, list) + drm_printf(&p, "%s\n", client->name); + mutex_unlock(&dev->clientlist_mutex); + + return 0; +} + +static const struct drm_debugfs_info drm_client_debugfs_list[] = { + { "internal_clients", drm_client_debugfs_internal_clients, 0 }, +}; + +void drm_client_debugfs_init(struct drm_minor *minor) +{ + drm_debugfs_add_files(minor->dev, drm_client_debugfs_list, + ARRAY_SIZE(drm_client_debugfs_list)); +} +#endif |