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linux/include/drm/drm_client.h
Thomas Zimmermann b4b0193e83 drm/fbdev-generic: Fix locking with drm_client_buffer_vmap_local()
Temporarily lock the fbdev buffer object during updates to prevent
memory managers from evicting/moving the buffer. Moving a buffer
object while update its content results in undefined behaviour.

Fbdev-generic updates its buffer object from a shadow buffer. Gem-shmem
and gem-dma helpers do not move buffer objects, so they are safe to be
used with fbdev-generic. Gem-vram and qxl are based on TTM, but pin
buffer objects are part of the vmap operation. So both are also safe
to be used with fbdev-generic.

Amdgpu and nouveau do not pin or lock the buffer object during an
update. Their TTM-based memory management could move the buffer object
while the update is ongoing.

The new vmap_local and vunmap_local helpers hold the buffer object's
reservation lock during the buffer update. This prevents moving the
buffer object on all memory managers.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Tested-by: Dmitry Osipenko <dmitry.osipenko@collabora.com> # virtio-gpu
Acked-by: Zack Rusin <zack.rusin@broadcom.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240227113853.8464-11-tzimmermann@suse.de
2024-03-11 13:33:50 +01:00

211 lines
5.6 KiB
C

/* SPDX-License-Identifier: GPL-2.0 or MIT */
#ifndef _DRM_CLIENT_H_
#define _DRM_CLIENT_H_
#include <linux/iosys-map.h>
#include <linux/lockdep.h>
#include <linux/mutex.h>
#include <linux/types.h>
#include <drm/drm_connector.h>
#include <drm/drm_crtc.h>
struct drm_client_dev;
struct drm_device;
struct drm_file;
struct drm_framebuffer;
struct drm_gem_object;
struct drm_minor;
struct module;
/**
* struct drm_client_funcs - DRM client callbacks
*/
struct drm_client_funcs {
/**
* @owner: The module owner
*/
struct module *owner;
/**
* @unregister:
*
* Called when &drm_device is unregistered. The client should respond by
* releasing its resources using drm_client_release().
*
* This callback is optional.
*/
void (*unregister)(struct drm_client_dev *client);
/**
* @restore:
*
* Called on drm_lastclose(). The first client instance in the list that
* returns zero gets the privilege to restore and no more clients are
* called. This callback is not called after @unregister has been called.
*
* Note that the core does not guarantee exclusion against concurrent
* drm_open(). Clients need to ensure this themselves, for example by
* using drm_master_internal_acquire() and
* drm_master_internal_release().
*
* This callback is optional.
*/
int (*restore)(struct drm_client_dev *client);
/**
* @hotplug:
*
* Called on drm_kms_helper_hotplug_event().
* This callback is not called after @unregister has been called.
*
* This callback is optional.
*/
int (*hotplug)(struct drm_client_dev *client);
};
/**
* struct drm_client_dev - DRM client instance
*/
struct drm_client_dev {
/**
* @dev: DRM device
*/
struct drm_device *dev;
/**
* @name: Name of the client.
*/
const char *name;
/**
* @list:
*
* List of all clients of a DRM device, linked into
* &drm_device.clientlist. Protected by &drm_device.clientlist_mutex.
*/
struct list_head list;
/**
* @funcs: DRM client functions (optional)
*/
const struct drm_client_funcs *funcs;
/**
* @file: DRM file
*/
struct drm_file *file;
/**
* @modeset_mutex: Protects @modesets.
*/
struct mutex modeset_mutex;
/**
* @modesets: CRTC configurations
*/
struct drm_mode_set *modesets;
/**
* @hotplug_failed:
*
* Set by client hotplug helpers if the hotplugging failed
* before. It is usually not tried again.
*/
bool hotplug_failed;
};
int drm_client_init(struct drm_device *dev, struct drm_client_dev *client,
const char *name, const struct drm_client_funcs *funcs);
void drm_client_release(struct drm_client_dev *client);
void drm_client_register(struct drm_client_dev *client);
void drm_client_dev_unregister(struct drm_device *dev);
void drm_client_dev_hotplug(struct drm_device *dev);
void drm_client_dev_restore(struct drm_device *dev);
/**
* struct drm_client_buffer - DRM client buffer
*/
struct drm_client_buffer {
/**
* @client: DRM client
*/
struct drm_client_dev *client;
/**
* @pitch: Buffer pitch
*/
u32 pitch;
/**
* @gem: GEM object backing this buffer
*
* 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.
*/
struct drm_gem_object *gem;
/**
* @map: Virtual address for the buffer
*/
struct iosys_map map;
/**
* @fb: DRM framebuffer
*/
struct drm_framebuffer *fb;
};
struct drm_client_buffer *
drm_client_framebuffer_create(struct drm_client_dev *client, u32 width, u32 height, u32 format);
void drm_client_framebuffer_delete(struct drm_client_buffer *buffer);
int drm_client_framebuffer_flush(struct drm_client_buffer *buffer, struct drm_rect *rect);
int drm_client_buffer_vmap_local(struct drm_client_buffer *buffer,
struct iosys_map *map_copy);
void drm_client_buffer_vunmap_local(struct drm_client_buffer *buffer);
int drm_client_buffer_vmap(struct drm_client_buffer *buffer,
struct iosys_map *map);
void drm_client_buffer_vunmap(struct drm_client_buffer *buffer);
int drm_client_modeset_create(struct drm_client_dev *client);
void drm_client_modeset_free(struct drm_client_dev *client);
int drm_client_modeset_probe(struct drm_client_dev *client, unsigned int width, unsigned int height);
bool drm_client_rotation(struct drm_mode_set *modeset, unsigned int *rotation);
int drm_client_modeset_check(struct drm_client_dev *client);
int drm_client_modeset_commit_locked(struct drm_client_dev *client);
int drm_client_modeset_commit(struct drm_client_dev *client);
int drm_client_modeset_dpms(struct drm_client_dev *client, int mode);
/**
* drm_client_for_each_modeset() - Iterate over client modesets
* @modeset: &drm_mode_set loop cursor
* @client: DRM client
*/
#define drm_client_for_each_modeset(modeset, client) \
for (({ lockdep_assert_held(&(client)->modeset_mutex); }), \
modeset = (client)->modesets; modeset->crtc; modeset++)
/**
* drm_client_for_each_connector_iter - connector_list iterator macro
* @connector: &struct drm_connector pointer used as cursor
* @iter: &struct drm_connector_list_iter
*
* This iterates the connectors that are useable for internal clients (excludes
* writeback connectors).
*
* For more info see drm_for_each_connector_iter().
*/
#define drm_client_for_each_connector_iter(connector, iter) \
drm_for_each_connector_iter(connector, iter) \
if (connector->connector_type != DRM_MODE_CONNECTOR_WRITEBACK)
void drm_client_debugfs_init(struct drm_device *dev);
#endif