diff options
| -rw-r--r-- | Documentation/gpu/drm-kms.rst | 88 | ||||
| -rw-r--r-- | drivers/gpu/drm/drm_property.c | 153 | ||||
| -rw-r--r-- | include/drm/drm_property.h | 196 |
3 files changed, 244 insertions, 193 deletions
diff --git a/Documentation/gpu/drm-kms.rst b/Documentation/gpu/drm-kms.rst index e07a2667ab61..f9a991bb87d4 100644 --- a/Documentation/gpu/drm-kms.rst +++ b/Documentation/gpu/drm-kms.rst @@ -304,94 +304,12 @@ KMS Locking KMS Properties ============== -Drivers may need to expose additional parameters to applications than -those described in the previous sections. KMS supports attaching -properties to CRTCs, connectors and planes and offers a userspace API to -list, get and set the property values. - -Properties are identified by a name that uniquely defines the property -purpose, and store an associated value. For all property types except -blob properties the value is a 64-bit unsigned integer. - -KMS differentiates between properties and property instances. Drivers -first create properties and then create and associate individual -instances of those properties to objects. A property can be instantiated -multiple times and associated with different objects. Values are stored -in property instances, and all other property information are stored in -the property and shared between all instances of the property. - -Every property is created with a type that influences how the KMS core -handles the property. Supported property types are - -DRM_MODE_PROP_RANGE - Range properties report their minimum and maximum admissible values. - The KMS core verifies that values set by application fit in that - range. - -DRM_MODE_PROP_ENUM - Enumerated properties take a numerical value that ranges from 0 to - the number of enumerated values defined by the property minus one, - and associate a free-formed string name to each value. Applications - can retrieve the list of defined value-name pairs and use the - numerical value to get and set property instance values. - -DRM_MODE_PROP_BITMASK - Bitmask properties are enumeration properties that additionally - restrict all enumerated values to the 0..63 range. Bitmask property - instance values combine one or more of the enumerated bits defined - by the property. - -DRM_MODE_PROP_BLOB - Blob properties store a binary blob without any format restriction. - The binary blobs are created as KMS standalone objects, and blob - property instance values store the ID of their associated blob - object. - - Blob properties are only used for the connector EDID property and - cannot be created by drivers. - -To create a property drivers call one of the following functions -depending on the property type. All property creation functions take -property flags and name, as well as type-specific arguments. - -- struct drm_property \*drm_property_create_range(struct - drm_device \*dev, int flags, const char \*name, uint64_t min, - uint64_t max); - Create a range property with the given minimum and maximum values. - -- struct drm_property \*drm_property_create_enum(struct drm_device - \*dev, int flags, const char \*name, const struct - drm_prop_enum_list \*props, int num_values); - Create an enumerated property. The ``props`` argument points to an - array of ``num_values`` value-name pairs. - -- struct drm_property \*drm_property_create_bitmask(struct - drm_device \*dev, int flags, const char \*name, const struct - drm_prop_enum_list \*props, int num_values); - Create a bitmask property. The ``props`` argument points to an array - of ``num_values`` value-name pairs. - -Properties can additionally be created as immutable, in which case they -will be read-only for applications but can be modified by the driver. To -create an immutable property drivers must set the -DRM_MODE_PROP_IMMUTABLE flag at property creation time. - -When no array of value-name pairs is readily available at property -creation time for enumerated or range properties, drivers can create the -property using the :c:func:`drm_property_create()` function and -manually add enumeration value-name pairs by calling the -:c:func:`drm_property_add_enum()` function. Care must be taken to -properly specify the property type through the ``flags`` argument. - -After creating properties drivers can attach property instances to CRTC, -connector and plane objects by calling the -:c:func:`drm_object_attach_property()`. The function takes a -pointer to the target object, a pointer to the previously created -property and an initial instance value. - Property Types and Blob Property Support ---------------------------------------- +.. kernel-doc:: drivers/gpu/drm/drm_property.c + :doc: overview + .. kernel-doc:: include/drm/drm_property.h :internal: diff --git a/drivers/gpu/drm/drm_property.c b/drivers/gpu/drm/drm_property.c index b5521f705b1c..4139afbcc267 100644 --- a/drivers/gpu/drm/drm_property.c +++ b/drivers/gpu/drm/drm_property.c @@ -26,6 +26,30 @@ #include "drm_crtc_internal.h" +/** + * DOC: overview + * + * Properties as represented by &drm_property are used to extend the modeset + * interface exposed to userspace. For the atomic modeset IOCTL properties are + * even the only way to transport metadata about the desired new modeset + * configuration from userspace to the kernel. Properties have a well-defined + * value range, which is enforced by the drm core. See the documentation of the + * flags member of struct &drm_property for an overview of the different + * property types and ranges. + * + * Properties don't store the current value directly, but need to be + * instatiated by attaching them to a &drm_mode_object with + * drm_object_attach_property(). + * + * Property values are only 64bit. To support bigger piles of data (like gamma + * tables, color correction matrizes or large structures) a property can instead + * point at a &drm_property_blob with that additional data + * + * Properties are defined by their symbolic name, userspace must keep a + * per-object mapping from those names to the property ID used in the atomic + * IOCTL and in the get/set property IOCTL. + */ + static bool drm_property_type_valid(struct drm_property *property) { if (property->flags & DRM_MODE_PROP_EXTENDED_TYPE) @@ -42,11 +66,8 @@ static bool drm_property_type_valid(struct drm_property *property) * * This creates a new generic drm property which can then be attached to a drm * object with drm_object_attach_property. The returned property object must be - * freed with drm_property_destroy. - * - * Note that the DRM core keeps a per-device list of properties and that, if - * drm_mode_config_cleanup() is called, it will destroy all properties created - * by the driver. + * freed with drm_property_destroy(), which is done automatically when calling + * drm_mode_config_cleanup(). * * Returns: * A pointer to the newly created property on success, NULL on failure. @@ -105,7 +126,8 @@ EXPORT_SYMBOL(drm_property_create); * * This creates a new generic drm property which can then be attached to a drm * object with drm_object_attach_property. The returned property object must be - * freed with drm_property_destroy. + * freed with drm_property_destroy(), which is done automatically when calling + * drm_mode_config_cleanup(). * * Userspace is only allowed to set one of the predefined values for enumeration * properties. @@ -152,7 +174,8 @@ EXPORT_SYMBOL(drm_property_create_enum); * * This creates a new bitmask drm property which can then be attached to a drm * object with drm_object_attach_property. The returned property object must be - * freed with drm_property_destroy. + * freed with drm_property_destroy(), which is done automatically when calling + * drm_mode_config_cleanup(). * * Compared to plain enumeration properties userspace is allowed to set any * or'ed together combination of the predefined property bitflag values @@ -223,7 +246,8 @@ static struct drm_property *property_create_range(struct drm_device *dev, * * This creates a new generic drm property which can then be attached to a drm * object with drm_object_attach_property. The returned property object must be - * freed with drm_property_destroy. + * freed with drm_property_destroy(), which is done automatically when calling + * drm_mode_config_cleanup(). * * Userspace is allowed to set any unsigned integer value in the (min, max) * range inclusive. @@ -250,7 +274,8 @@ EXPORT_SYMBOL(drm_property_create_range); * * This creates a new generic drm property which can then be attached to a drm * object with drm_object_attach_property. The returned property object must be - * freed with drm_property_destroy. + * freed with drm_property_destroy(), which is done automatically when calling + * drm_mode_config_cleanup(). * * Userspace is allowed to set any signed integer value in the (min, max) * range inclusive. @@ -276,7 +301,8 @@ EXPORT_SYMBOL(drm_property_create_signed_range); * * This creates a new generic drm property which can then be attached to a drm * object with drm_object_attach_property. The returned property object must be - * freed with drm_property_destroy. + * freed with drm_property_destroy(), which is done automatically when calling + * drm_mode_config_cleanup(). * * Userspace is only allowed to set this to any property value of the given * @type. Only useful for atomic properties, which is enforced. @@ -285,7 +311,8 @@ EXPORT_SYMBOL(drm_property_create_signed_range); * A pointer to the newly created property on success, NULL on failure. */ struct drm_property *drm_property_create_object(struct drm_device *dev, - int flags, const char *name, uint32_t type) + int flags, const char *name, + uint32_t type) { struct drm_property *property; @@ -312,7 +339,8 @@ EXPORT_SYMBOL(drm_property_create_object); * * This creates a new generic drm property which can then be attached to a drm * object with drm_object_attach_property. The returned property object must be - * freed with drm_property_destroy. + * freed with drm_property_destroy(), which is done automatically when calling + * drm_mode_config_cleanup(). * * This is implemented as a ranged property with only {0, 1} as valid values. * @@ -320,7 +348,7 @@ EXPORT_SYMBOL(drm_property_create_object); * A pointer to the newly created property on success, NULL on failure. */ struct drm_property *drm_property_create_bool(struct drm_device *dev, int flags, - const char *name) + const char *name) { return drm_property_create_range(dev, flags, name, 0, 1); } @@ -407,22 +435,6 @@ void drm_property_destroy(struct drm_device *dev, struct drm_property *property) } EXPORT_SYMBOL(drm_property_destroy); -/** - * drm_mode_getproperty_ioctl - get the property metadata - * @dev: DRM device - * @data: ioctl data - * @file_priv: DRM file info - * - * This function retrieves the metadata for a given property, like the different - * possible values for an enum property or the limits for a range property. - * - * Blob properties are special - * - * Called by the user via ioctl. - * - * Returns: - * Zero on success, negative errno on failure. - */ int drm_mode_getproperty_ioctl(struct drm_device *dev, void *data, struct drm_file *file_priv) { @@ -523,14 +535,14 @@ static void drm_property_free_blob(struct kref *kref) /** * drm_property_create_blob - Create new blob property - * - * Creates a new blob property for a specified DRM device, optionally - * copying data. - * * @dev: DRM device to create property for * @length: Length to allocate for blob data * @data: If specified, copies data into blob * + * Creates a new blob property for a specified DRM device, optionally + * copying data. Note that blob properties are meant to be invariant, hence the + * data must be filled out before the blob is used as the value of any property. + * * Returns: * New blob property with a single reference on success, or an ERR_PTR * value on failure. @@ -576,10 +588,9 @@ EXPORT_SYMBOL(drm_property_create_blob); /** * drm_property_unreference_blob - Unreference a blob property + * @blob: Pointer to blob property * * Drop a reference on a blob property. May free the object. - * - * @blob: Pointer to blob property */ void drm_property_unreference_blob(struct drm_property_blob *blob) { @@ -590,11 +601,6 @@ void drm_property_unreference_blob(struct drm_property_blob *blob) } EXPORT_SYMBOL(drm_property_unreference_blob); -/** - * drm_property_destroy_user_blobs - destroy all blobs created by this client - * @dev: DRM device - * @file_priv: destroy all blobs owned by this file handle - */ void drm_property_destroy_user_blobs(struct drm_device *dev, struct drm_file *file_priv) { @@ -612,10 +618,10 @@ void drm_property_destroy_user_blobs(struct drm_device *dev, /** * drm_property_reference_blob - Take a reference on an existing property - * - * Take a new reference on an existing blob property. - * * @blob: Pointer to blob property + * + * Take a new reference on an existing blob property. Returns @blob, which + * allows this to be used as a shorthand in assignments. */ struct drm_property_blob *drm_property_reference_blob(struct drm_property_blob *blob) { @@ -632,6 +638,9 @@ EXPORT_SYMBOL(drm_property_reference_blob); * If successful, this takes an additional reference to the blob property. * callers need to make sure to eventually unreference the returned property * again, using @drm_property_unreference_blob. + * + * Return: + * NULL on failure, pointer to the blob on success. */ struct drm_property_blob *drm_property_lookup_blob(struct drm_device *dev, uint32_t id) @@ -647,7 +656,7 @@ struct drm_property_blob *drm_property_lookup_blob(struct drm_device *dev, EXPORT_SYMBOL(drm_property_lookup_blob); /** - * drm_property_replace_global_blob - atomically replace existing blob property + * drm_property_replace_global_blob - replace existing blob property * @dev: drm device * @replace: location of blob property pointer to be replaced * @length: length of data for new blob, or 0 for no data @@ -656,11 +665,8 @@ EXPORT_SYMBOL(drm_property_lookup_blob); * @prop_holds_id: optional property holding blob ID * @return 0 on success or error on failure * - * This function will atomically replace a global property in the blob list, - * optionally updating a property which holds the ID of that property. It is - * guaranteed to be atomic: no caller will be allowed to see intermediate - * results, and either the entire operation will succeed and clean up the - * previous property, or it will fail and the state will be unchanged. + * This function will replace a global property in the blob list, optionally + * updating a property which holds the ID of that property. * * If length is 0 or data is NULL, no new blob will be created, and the holding * property, if specified, will be set to 0. @@ -697,11 +703,6 @@ int drm_property_replace_global_blob(struct drm_device *dev, return PTR_ERR(new_blob); } - /* This does not need to be synchronised with blob_lock, as the - * get_properties ioctl locks all modesetting objects, and - * obj_holds_id must be locked before calling here, so we cannot - * have its value out of sync with the list membership modified - * below under blob_lock. */ if (obj_holds_id) { ret = drm_object_property_set_value(obj_holds_id, prop_holds_id, @@ -722,20 +723,6 @@ err_created: } EXPORT_SYMBOL(drm_property_replace_global_blob); -/** - * drm_mode_getblob_ioctl - get the contents of a blob property value - * @dev: DRM device - * @data: ioctl data - * @file_priv: DRM file info - * - * This function retrieves the contents of a blob property. The value stored in - * an object's blob property is just a normal modeset object id. - * - * Called by the user via ioctl. - * - * Returns: - * Zero on success, negative errno on failure. - */ int drm_mode_getblob_ioctl(struct drm_device *dev, void *data, struct drm_file *file_priv) { @@ -765,21 +752,6 @@ unref: return ret; } -/** - * drm_mode_createblob_ioctl - create a new blob property - * @dev: DRM device - * @data: ioctl data - * @file_priv: DRM file info - * - * This function creates a new blob property with user-defined values. In order - * to give us sensible validation and checking when creating, rather than at - * every potential use, we also require a type to be provided upfront. - * - * Called by the user via ioctl. - * - * Returns: - * Zero on success, negative errno on failure. - */ int drm_mode_createblob_ioctl(struct drm_device *dev, void *data, struct drm_file *file_priv) { @@ -816,19 +788,6 @@ out_blob: return ret; } -/** - * drm_mode_destroyblob_ioctl - destroy a user blob property - * @dev: DRM device - * @data: ioctl data - * @file_priv: DRM file info - * - * Destroy an existing user-defined blob property. - * - * Called by the user via ioctl. - * - * Returns: - * Zero on success, negative errno on failure. - */ int drm_mode_destroyblob_ioctl(struct drm_device *dev, void *data, struct drm_file *file_priv) { @@ -885,7 +844,7 @@ err: * reference). */ bool drm_property_change_valid_get(struct drm_property *property, - uint64_t value, struct drm_mode_object **ref) + uint64_t value, struct drm_mode_object **ref) { int i; diff --git a/include/drm/drm_property.h b/include/drm/drm_property.h index ac40069358c7..30ab289be05d 100644 --- a/include/drm/drm_property.h +++ b/include/drm/drm_property.h @@ -27,33 +27,192 @@ #include <linux/ctype.h> #include <drm/drm_mode_object.h> -struct drm_property_blob { - struct drm_mode_object base; - struct drm_device *dev; - struct list_head head_global; - struct list_head head_file; - size_t length; - unsigned char data[]; -}; - +/** + * struct drm_property_enum - symbolic values for enumerations + * @value: numeric property value for this enum entry + * @head: list of enum values, linked to enum_list in &drm_property + * @name: symbolic name for the enum + * + * For enumeration and bitmask properties this structure stores the symbolic + * decoding for each value. This is used for example for the rotation property. + */ struct drm_property_enum { uint64_t value; struct list_head head; char name[DRM_PROP_NAME_LEN]; }; +/** + * struct drm_property - modeset object property + * + * This structure represent a modeset object property. It combines both the name + * of the property with the set of permissible values. This means that when a + * driver wants to use a property with the same name on different objects, but + * with different value ranges, then it must create property for each one. An + * example would be rotation of &drm_plane, when e.g. the primary plane cannot + * be rotated. But if both the name and the value range match, then the same + * property structure can be instantiated multiple times for the same object. + * Userspace must be able to cope with this and cannot assume that the same + * symbolic property will have the same modeset object ID on all modeset + * objects. + * + * Properties are created by one of the special functions, as explained in + * detail in the @flags structure member. + * + * To actually expose a property it must be attached to each object using + * drm_object_attach_property(). Currently properties can only be attached to + * &drm_connector, &drm_crtc and &drm_plane. + * + * Properties are also used as the generic metadatatransport for the atomic + * IOCTL. Everything that was set directly in structures in the legacy modeset + * IOCTLs (like the plane source or destination windows, or e.g. the links to + * the CRTC) is exposed as a property with the DRM_MODE_PROP_ATOMIC flag set. + */ struct drm_property { + /** + * @head: per-device list of properties, for cleanup. + */ struct list_head head; + + /** + * @base: base KMS object + */ struct drm_mode_object base; + + /** + * @flags: + * + * Property flags and type. A property needs to be one of the following + * types: + * + * DRM_MODE_PROP_RANGE + * Range properties report their minimum and maximum admissible unsigned values. + * The KMS core verifies that values set by application fit in that + * range. The range is unsigned. Range properties are created using + * drm_property_create_range(). + * + * DRM_MODE_PROP_SIGNED_RANGE + * Range properties report their minimum and maximum admissible unsigned values. + * The KMS core verifies that values set by application fit in that + * range. The range is signed. Range properties are created using + * drm_property_create_signed_range(). + * + * DRM_MODE_PROP_ENUM + * Enumerated properties take a numerical value that ranges from 0 to + * the number of enumerated values defined by the property minus one, + * and associate a free-formed string name to each value. Applications + * can retrieve the list of defined value-name pairs and use the + * numerical value to get and set property instance values. Enum + * properties are created using drm_property_create_enum(). + * + * DRM_MODE_PROP_BITMASK + * Bitmask properties are enumeration properties that additionally + * restrict all enumerated values to the 0..63 range. Bitmask property + * instance values combine one or more of the enumerated bits defined + * by the property. Bitmask properties are created using + * drm_property_create_bitmask(). + * + * DRM_MODE_PROB_OBJECT + * Object properties are used to link modeset objects. This is used + * extensively in the atomic support to create the display pipeline, + * by linking &drm_framebuffer to &drm_plane, &drm_plane to + * &drm_crtc and &drm_connector to &drm_crtc. An object property can + * only link to a specific type of &drm_mode_object, this limit is + * enforced by the core. Object properties are created using + * drm_property_create_object(). + * + * Object properties work like blob properties, but in a more + * general fashion. They are limited to atomic drivers and must have + * the DRM_MODE_PROP_ATOMIC flag set. + * + * DRM_MODE_PROP_BLOB + * Blob properties store a binary blob without any format restriction. + * The binary blobs are created as KMS standalone objects, and blob + * property instance values store the ID of their associated blob + * object. Blob properties are created by calling + * drm_property_create() with DRM_MODE_PROP_BLOB as the type. + * + * Actual blob objects to contain blob data are created using + * drm_property_create_blob(), or through the corresponding IOCTL. + * + * Besides the built-in limit to only accept blob objects blob + * properties work exactly like object properties. The only reasons + * blob properties exist is backwards compatibility with existing + * userspace. + * + * In addition a property can have any combination of the below flags: + * + * DRM_MODE_PROP_ATOMIC + * Set for properties which encode atomic modeset state. Such + * properties are not exposed to legacy userspace. + * + * DRM_MODE_PROP_IMMUTABLE + * Set for properties where userspace cannot be changed by + * userspace. The kernel is allowed to update the value of these + * properties. This is generally used to expose probe state to + * usersapce, e.g. the EDID, or the connector path property on DP + * MST sinks. + */ uint32_t flags; + + /** + * @name: symbolic name of the properties + */ char name[DRM_PROP_NAME_LEN]; + + /** + * @num_values: size of the @values array. + */ uint32_t num_values; + + /** + * @values: + * + * Array with limits and values for the property. The + * interpretation of these limits is dependent upon the type per @flags. + */ uint64_t *values; + + /** + * @dev: DRM device + */ struct drm_device *dev; + /** + * @enum_list: + * + * List of &drm_prop_enum_list structures with the symbolic names for + * enum and bitmask values. + */ struct list_head enum_list; }; +/** + * struct drm_property_blob - Blob data for &drm_property + * @base: base KMS object + * @dev: DRM device + * @head_global: entry on the global blob list in &drm_mode_config + * property_blob_list. + * @head_file: entry on the per-file blob list in &drm_file blobs list. + * @length: size of the blob in bytes, invariant over the lifetime of the object + * @data: actual data, embedded at the end of this structure + * + * Blobs are used to store bigger values than what fits directly into the 64 + * bits available for a &drm_property. + * + * Blobs are reference counted using drm_property_reference_blob() and + * drm_property_unreference_blob(). They are created using + * drm_property_create_blob(). + */ +struct drm_property_blob { + struct drm_mode_object base; + struct drm_device *dev; + struct list_head head_global; + struct list_head head_file; + size_t length; + unsigned char data[]; +}; + struct drm_prop_enum_list { int type; char *name; @@ -61,8 +220,16 @@ struct drm_prop_enum_list { #define obj_to_property(x) container_of(x, struct drm_property, base) +/** + * drm_property_type_is - check the type of a property + * @property: property to check + * @type: property type to compare with + * + * This is a helper function becauase the uapi encoding of property types is + * a bit special for historical reasons. + */ static inline bool drm_property_type_is(struct drm_property *property, - uint32_t type) + uint32_t type) { /* instanceof for props.. handles extended type vs original types: */ if (property->flags & DRM_MODE_PROP_EXTENDED_TYPE) @@ -109,8 +276,15 @@ int drm_property_replace_global_blob(struct drm_device *dev, struct drm_property_blob *drm_property_reference_blob(struct drm_property_blob *blob); void drm_property_unreference_blob(struct drm_property_blob *blob); +/** + * drm_connector_find - find property object + * @dev: DRM device + * @id: property object id + * + * This function looks up the property object specified by id and returns it. + */ static inline struct drm_property *drm_property_find(struct drm_device *dev, - uint32_t id) + uint32_t id) { struct drm_mode_object *mo; mo = drm_mode_object_find(dev, id, DRM_MODE_OBJECT_PROPERTY); |