Also extract drm_auth.h for nicer grouping.
v2: Nuke the other comments since they don't really explain a lot, and within the drm core we generally only document functions exported to drivers: The main audience for these docs are driver writers.
v3: Limit the exposure of drm_master internals by only including drm_auth.h where it is neede (Chris).
v4: Spelling polish (Emil).
Cc: Chris Wilson chris@chris-wilson.co.uk Reviewed-by: Chris Wilson chris@chris-wilson.co.uk Reviewed-by: Emil Velikov emil.l.velikov@gmail.com Signed-off-by: Daniel Vetter daniel.vetter@intel.com --- Documentation/DocBook/gpu.tmpl | 6 ++++ drivers/gpu/drm/drm_auth.c | 69 +++++++++++++++++++++---------------- drivers/gpu/drm/drm_crtc.c | 1 + drivers/gpu/drm/drm_ioctl.c | 1 + drivers/gpu/drm/i915/i915_drv.h | 1 + drivers/gpu/drm/vmwgfx/vmwgfx_drv.h | 1 + include/drm/drmP.h | 30 +--------------- include/drm/drm_auth.h | 59 +++++++++++++++++++++++++++++++ include/drm/drm_legacy.h | 2 ++ 9 files changed, 112 insertions(+), 58 deletions(-) create mode 100644 include/drm/drm_auth.h
diff --git a/Documentation/DocBook/gpu.tmpl b/Documentation/DocBook/gpu.tmpl index 94c6bdee8080..b7f6316b7bee 100644 --- a/Documentation/DocBook/gpu.tmpl +++ b/Documentation/DocBook/gpu.tmpl @@ -3103,6 +3103,12 @@ int num_ioctls;</synopsis> !Pdrivers/gpu/drm/drm_vma_manager.c getunique and setversion story </sect1> <sect1> + <title>Primary Nodes, DRM Master and Authentication</title> +!Pdrivers/gpu/drm_auth.c master and authentication +!Edrivers/gpu/drm_auth.c +!Einclude/drm/drm_auth.h + </sect1> + <sect1> <title>Render nodes</title> <para> DRM core provides multiple character-devices for user-space to use. diff --git a/drivers/gpu/drm/drm_auth.c b/drivers/gpu/drm/drm_auth.c index 0a23b32e627c..c07112b3c3c0 100644 --- a/drivers/gpu/drm/drm_auth.c +++ b/drivers/gpu/drm/drm_auth.c @@ -32,18 +32,27 @@ #include "drm_internal.h" #include "drm_legacy.h"
-/** - * drm_getmagic - Get unique magic of a client - * @dev: DRM device to operate on - * @data: ioctl data containing the drm_auth object - * @file_priv: DRM file that performs the operation +/** DOC: master and authentication + * + * struct &drm_master is used to track groups of clients with open + * primary/legacy device nodes. For every struct &drm_file which has had at + * least once successfully became the device master (either through the + * SET_MASTER IOCTL, or implicitly through opening the primary device node when + * no one else is the current master that time) there exists one &drm_master. + * This is noted in the is_master member of &drm_file. All other clients have + * just a pointer to the &drm_master they are associated with. * - * This looks up the unique magic of the passed client and returns it. If the - * client did not have a magic assigned, yet, a new one is registered. The magic - * is stored in the passed drm_auth object. + * In addition only one &drm_master can be the current master for a &drm_device. + * It can be switched through the DROP_MASTER and SET_MASTER IOCTL, or + * implicitly through closing/openeing the primary device node. See also + * drm_is_current_master(). * - * Returns: 0 on success, negative error code on failure. + * Clients can authenticate against the current master (if it matches their own) + * using the GETMAGIC and AUTHMAGIC IOCTLs. Together with exchanging masters, + * this allows controlled access to the device for an entire group of mutually + * trusted clients. */ + int drm_getmagic(struct drm_device *dev, void *data, struct drm_file *file_priv) { struct drm_auth *auth = data; @@ -64,16 +73,6 @@ int drm_getmagic(struct drm_device *dev, void *data, struct drm_file *file_priv) return ret < 0 ? ret : 0; }
-/** - * drm_authmagic - Authenticate client with a magic - * @dev: DRM device to operate on - * @data: ioctl data containing the drm_auth object - * @file_priv: DRM file that performs the operation - * - * This looks up a DRM client by the passed magic and authenticates it. - * - * Returns: 0 on success, negative error code on failure. - */ int drm_authmagic(struct drm_device *dev, void *data, struct drm_file *file_priv) { @@ -126,16 +125,6 @@ static int drm_set_master(struct drm_device *dev, struct drm_file *fpriv, return ret; }
-/* - * drm_new_set_master - Allocate a new master object and become master for the - * associated master realm. - * - * @dev: The associated device. - * @fpriv: File private identifying the client. - * - * This function must be called with dev::master_mutex held. - * Returns negative error code on failure. Zero on success. - */ static int drm_new_set_master(struct drm_device *dev, struct drm_file *fpriv) { struct drm_master *old_master; @@ -286,12 +275,28 @@ out: mutex_unlock(&dev->master_mutex); }
+/** + * drm_is_current_master - checks whether @priv is the current master + * @fpriv: DRM file private + * + * Checks whether @fpriv is current master on its device. This decides whether a + * client is allowed to run DRM_MASTER IOCTLs. + * + * Most of the modern IOCTL which require DRM_MASTER are for kernel modesetting + * - the current master is assumed to own the non-shareable display hardware. + */ bool drm_is_current_master(struct drm_file *fpriv) { return fpriv->is_master && fpriv->master == fpriv->minor->dev->master; } EXPORT_SYMBOL(drm_is_current_master);
+/** + * drm_master_get - reference a master pointer + * @master: struct &drm_master + * + * Increments the reference count of @master and returns a pointer to @master. + */ struct drm_master *drm_master_get(struct drm_master *master) { kref_get(&master->refcount); @@ -314,6 +319,12 @@ static void drm_master_destroy(struct kref *kref) kfree(master); }
+/** + * drm_master_put - unreference and clear a master pointer + * @master: pointer to a pointer of struct &drm_master + * + * This decrements the &drm_master behind @master and sets it to NULL. + */ void drm_master_put(struct drm_master **master) { kref_put(&(*master)->refcount, drm_master_destroy); diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c index 2a4c5a408bbe..db93487a3cc4 100644 --- a/drivers/gpu/drm/drm_crtc.c +++ b/drivers/gpu/drm/drm_crtc.c @@ -39,6 +39,7 @@ #include <drm/drm_fourcc.h> #include <drm/drm_modeset_lock.h> #include <drm/drm_atomic.h> +#include <drm/drm_auth.h>
#include "drm_crtc_internal.h" #include "drm_internal.h" diff --git a/drivers/gpu/drm/drm_ioctl.c b/drivers/gpu/drm/drm_ioctl.c index 8e921670020e..699a89d22f43 100644 --- a/drivers/gpu/drm/drm_ioctl.c +++ b/drivers/gpu/drm/drm_ioctl.c @@ -30,6 +30,7 @@
#include <drm/drmP.h> #include <drm/drm_core.h> +#include <drm/drm_auth.h> #include "drm_legacy.h" #include "drm_internal.h" #include "drm_crtc_internal.h" diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index 48928227bdcc..811ee198a561 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -47,6 +47,7 @@ #include <drm/intel-gtt.h> #include <drm/drm_legacy.h> /* for struct drm_dma_handle */ #include <drm/drm_gem.h> +#include <drm/drm_auth.h>
#include "i915_params.h" #include "i915_reg.h" diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h index 1980e2a28265..9a90f824814e 100644 --- a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h @@ -32,6 +32,7 @@ #include <drm/drmP.h> #include <drm/vmwgfx_drm.h> #include <drm/drm_hashtab.h> +#include <drm/drm_auth.h> #include <linux/suspend.h> #include <drm/ttm/ttm_bo_driver.h> #include <drm/ttm/ttm_object.h> diff --git a/include/drm/drmP.h b/include/drm/drmP.h index 128a03bfdebd..28d341afbf6c 100644 --- a/include/drm/drmP.h +++ b/include/drm/drmP.h @@ -86,6 +86,7 @@ struct drm_local_map; struct drm_device_dma; struct drm_dma_handle; struct drm_gem_object; +struct drm_master;
struct device_node; struct videomode; @@ -373,30 +374,6 @@ struct drm_lock_data { int idle_has_lock; };
-/** - * struct drm_master - drm master structure - * - * @refcount: Refcount for this master object. - * @dev: Link back to the DRM device - * @unique: Unique identifier: e.g. busid. Protected by drm_global_mutex. - * @unique_len: Length of unique field. Protected by drm_global_mutex. - * @magic_map: Map of used authentication tokens. Protected by struct_mutex. - * @lock: DRI lock information. - * @driver_priv: Pointer to driver-private information. - * - * Note that master structures are only relevant for the legacy/primary device - * nodes, hence there can only be one per device, not one per drm_minor. - */ -struct drm_master { - struct kref refcount; - struct drm_device *dev; - char *unique; - int unique_len; - struct idr magic_map; - struct drm_lock_data lock; - void *driver_priv; -}; - /* Flags and return codes for get_vblank_timestamp() driver function. */ #define DRM_CALLED_FROM_VBLIRQ 1 #define DRM_VBLANKTIME_SCANOUTPOS_METHOD (1 << 0) @@ -1008,11 +985,6 @@ static inline wait_queue_head_t *drm_crtc_vblank_waitqueue(struct drm_crtc *crtc return &crtc->dev->vblank[drm_crtc_index(crtc)].queue; }
-/* drm_auth.c */ -struct drm_master *drm_master_get(struct drm_master *master); -void drm_master_put(struct drm_master **master); -bool drm_is_current_master(struct drm_file *fpriv); - /* drm_drv.c */ void drm_put_dev(struct drm_device *dev); void drm_unplug_dev(struct drm_device *dev); diff --git a/include/drm/drm_auth.h b/include/drm/drm_auth.h new file mode 100644 index 000000000000..610223b0481b --- /dev/null +++ b/include/drm/drm_auth.h @@ -0,0 +1,59 @@ +/* + * Internal Header for the Direct Rendering Manager + * + * Copyright 2016 Intel Corporation + * + * Author: Daniel Vetter daniel.vetter@ffwll.ch + * + * Permission is hereby granted, free of charge, to any person obtaining a + * copy of this software and associated documentation files (the "Software"), + * to deal in the Software without restriction, including without limitation + * the rights to use, copy, modify, merge, publish, distribute, sublicense, + * and/or sell copies of the Software, and to permit persons to whom the + * Software is furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice (including the next + * paragraph) shall be included in all copies or substantial portions of the + * Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL + * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR + * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, + * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR + * OTHER DEALINGS IN THE SOFTWARE. + */ + +#ifndef _DRM_AUTH_H_ +#define _DRM_AUTH_H_ + +/** + * struct drm_master - drm master structure + * + * @refcount: Refcount for this master object. + * @dev: Link back to the DRM device + * @unique: Unique identifier: e.g. busid. Protected by drm_global_mutex. + * @unique_len: Length of unique field. Protected by drm_global_mutex. + * @magic_map: Map of used authentication tokens. Protected by struct_mutex. + * @lock: DRI lock information. + * @driver_priv: Pointer to driver-private information. + * + * Note that master structures are only relevant for the legacy/primary device + * nodes, hence there can only be one per device, not one per drm_minor. + */ +struct drm_master { + struct kref refcount; + struct drm_device *dev; + char *unique; + int unique_len; + struct idr magic_map; + struct drm_lock_data lock; + void *driver_priv; +}; + +struct drm_master *drm_master_get(struct drm_master *master); +void drm_master_put(struct drm_master **master); +bool drm_is_current_master(struct drm_file *fpriv); + +#endif diff --git a/include/drm/drm_legacy.h b/include/drm/drm_legacy.h index a5ef2c7e40f8..cf0e7d89bcdf 100644 --- a/include/drm/drm_legacy.h +++ b/include/drm/drm_legacy.h @@ -1,6 +1,8 @@ #ifndef __DRM_DRM_LEGACY_H__ #define __DRM_DRM_LEGACY_H__
+#include <drm/drm_auth.h> + /* * Legacy driver interfaces for the Direct Rendering Manager *