drm: Document kms locking a bit better

[mirror_ubuntu-hirsute-kernel.git] / include / drm / drm_plane.h

/*
 * Copyright (c) 2016 Intel Corporation
 *
 * Permission to use, copy, modify, distribute, and sell this software and its
 * documentation for any purpose is hereby granted without fee, provided that
 * the above copyright notice appear in all copies and that both that copyright
 * notice and this permission notice appear in supporting documentation, and
 * that the name of the copyright holders not be used in advertising or
 * publicity pertaining to distribution of the software without specific,
 * written prior permission.  The copyright holders make no representations
 * about the suitability of this software for any purpose.  It is provided "as
 * is" without express or implied warranty.
 *
 * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
 * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
 * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
 * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
 * OF THIS SOFTWARE.
 */

#ifndef __DRM_PLANE_H__
#define __DRM_PLANE_H__

#include <linux/list.h>
#include <linux/ctype.h>
#include <drm/drm_mode_object.h>

struct drm_crtc;
struct drm_printer;

/**
 * struct drm_plane_state - mutable plane state
 * @plane: backpointer to the plane
 * @crtc_w: width of visible portion of plane on crtc
 * @crtc_h: height of visible portion of plane on crtc
 * @src_x: left position of visible portion of plane within
 *      plane (in 16.16)
 * @src_y: upper position of visible portion of plane within
 *      plane (in 16.16)
 * @src_w: width of visible portion of plane (in 16.16)
 * @src_h: height of visible portion of plane (in 16.16)
 * @rotation: rotation of the plane
 * @zpos: priority of the given plane on crtc (optional)
 *      Note that multiple active planes on the same crtc can have an identical
 *      zpos value. The rule to solving the conflict is to compare the plane
 *      object IDs; the plane with a higher ID must be stacked on top of a
 *      plane with a lower ID.
 * @normalized_zpos: normalized value of zpos: unique, range from 0 to N-1
 *      where N is the number of active planes for given crtc. Note that
 *      the driver must call drm_atomic_normalize_zpos() to update this before
 *      it can be trusted.
 * @src: clipped source coordinates of the plane (in 16.16)
 * @dst: clipped destination coordinates of the plane
 * @state: backpointer to global drm_atomic_state
 */
struct drm_plane_state {
        struct drm_plane *plane;

        /**
         * @crtc:
         *
         * Currently bound CRTC, NULL if disabled. Do not this write directly,
         * use drm_atomic_set_crtc_for_plane()
         */
        struct drm_crtc *crtc;

        /**
         * @fb:
         *
         * Currently bound framebuffer. Do not write this directly, use
         * drm_atomic_set_fb_for_plane()
         */
        struct drm_framebuffer *fb;

        /**
         * @fence:
         *
         * Optional fence to wait for before scanning out @fb. Do not write this
         * directly, use drm_atomic_set_fence_for_plane()
         */
        struct dma_fence *fence;

        /**
         * @crtc_x:
         *
         * Left position of visible portion of plane on crtc, signed dest
         * location allows it to be partially off screen.
         */

        int32_t crtc_x;
        /**
         * @crtc_y:
         *
         * Upper position of visible portion of plane on crtc, signed dest
         * location allows it to be partially off screen.
         */
        int32_t crtc_y;

        uint32_t crtc_w, crtc_h;

        /* Source values are 16.16 fixed point */
        uint32_t src_x, src_y;
        uint32_t src_h, src_w;

        /* Plane rotation */
        unsigned int rotation;

        /* Plane zpos */
        unsigned int zpos;
        unsigned int normalized_zpos;

        /* Clipped coordinates */
        struct drm_rect src, dst;

        /**
         * @visible:
         *
         * Visibility of the plane. This can be false even if fb!=NULL and
         * crtc!=NULL, due to clipping.
         */
        bool visible;

        struct drm_atomic_state *state;
};

static inline struct drm_rect
drm_plane_state_src(const struct drm_plane_state *state)
{
        struct drm_rect src = {
                .x1 = state->src_x,
                .y1 = state->src_y,
                .x2 = state->src_x + state->src_w,
                .y2 = state->src_y + state->src_h,
        };
        return src;
}

static inline struct drm_rect
drm_plane_state_dest(const struct drm_plane_state *state)
{
        struct drm_rect dest = {
                .x1 = state->crtc_x,
                .y1 = state->crtc_y,
                .x2 = state->crtc_x + state->crtc_w,
                .y2 = state->crtc_y + state->crtc_h,
        };
        return dest;
}

/**
 * struct drm_plane_funcs - driver plane control functions
 */
struct drm_plane_funcs {
        /**
         * @update_plane:
         *
         * This is the legacy entry point to enable and configure the plane for
         * the given CRTC and framebuffer. It is never called to disable the
         * plane, i.e. the passed-in crtc and fb paramters are never NULL.
         *
         * The source rectangle in frame buffer memory coordinates is given by
         * the src_x, src_y, src_w and src_h parameters (as 16.16 fixed point
         * values). Devices that don't support subpixel plane coordinates can
         * ignore the fractional part.
         *
         * The destination rectangle in CRTC coordinates is given by the
         * crtc_x, crtc_y, crtc_w and crtc_h parameters (as integer values).
         * Devices scale the source rectangle to the destination rectangle. If
         * scaling is not supported, and the source rectangle size doesn't match
         * the destination rectangle size, the driver must return a
         * -<errorname>EINVAL</errorname> error.
         *
         * Drivers implementing atomic modeset should use
         * drm_atomic_helper_update_plane() to implement this hook.
         *
         * RETURNS:
         *
         * 0 on success or a negative error code on failure.
         */
        int (*update_plane)(struct drm_plane *plane,
                            struct drm_crtc *crtc, struct drm_framebuffer *fb,
                            int crtc_x, int crtc_y,
                            unsigned int crtc_w, unsigned int crtc_h,
                            uint32_t src_x, uint32_t src_y,
                            uint32_t src_w, uint32_t src_h);

        /**
         * @disable_plane:
         *
         * This is the legacy entry point to disable the plane. The DRM core
         * calls this method in response to a DRM_IOCTL_MODE_SETPLANE IOCTL call
         * with the frame buffer ID set to 0.  Disabled planes must not be
         * processed by the CRTC.
         *
         * Drivers implementing atomic modeset should use
         * drm_atomic_helper_disable_plane() to implement this hook.
         *
         * RETURNS:
         *
         * 0 on success or a negative error code on failure.
         */
        int (*disable_plane)(struct drm_plane *plane);

        /**
         * @destroy:
         *
         * Clean up plane resources. This is only called at driver unload time
         * through drm_mode_config_cleanup() since a plane cannot be hotplugged
         * in DRM.
         */
        void (*destroy)(struct drm_plane *plane);

        /**
         * @reset:
         *
         * Reset plane hardware and software state to off. This function isn't
         * called by the core directly, only through drm_mode_config_reset().
         * It's not a helper hook only for historical reasons.
         *
         * Atomic drivers can use drm_atomic_helper_plane_reset() to reset
         * atomic state using this hook.
         */
        void (*reset)(struct drm_plane *plane);

        /**
         * @set_property:
         *
         * This is the legacy entry point to update a property attached to the
         * plane.
         *
         * Drivers implementing atomic modeset should use
         * drm_atomic_helper_plane_set_property() to implement this hook.
         *
         * This callback is optional if the driver does not support any legacy
         * driver-private properties.
         *
         * RETURNS:
         *
         * 0 on success or a negative error code on failure.
         */
        int (*set_property)(struct drm_plane *plane,
                            struct drm_property *property, uint64_t val);

        /**
         * @atomic_duplicate_state:
         *
         * Duplicate the current atomic state for this plane and return it.
         * The core and helpers guarantee that any atomic state duplicated with
         * this hook and still owned by the caller (i.e. not transferred to the
         * driver by calling &drm_mode_config_funcs.atomic_commit) will be
         * cleaned up by calling the @atomic_destroy_state hook in this
         * structure.
         *
         * Atomic drivers which don't subclass &struct drm_plane_state should use
         * drm_atomic_helper_plane_duplicate_state(). Drivers that subclass the
         * state structure to extend it with driver-private state should use
         * __drm_atomic_helper_plane_duplicate_state() to make sure shared state is
         * duplicated in a consistent fashion across drivers.
         *
         * It is an error to call this hook before &drm_plane.state has been
         * initialized correctly.
         *
         * NOTE:
         *
         * If the duplicate state references refcounted resources this hook must
         * acquire a reference for each of them. The driver must release these
         * references again in @atomic_destroy_state.
         *
         * RETURNS:
         *
         * Duplicated atomic state or NULL when the allocation failed.
         */
        struct drm_plane_state *(*atomic_duplicate_state)(struct drm_plane *plane);

        /**
         * @atomic_destroy_state:
         *
         * Destroy a state duplicated with @atomic_duplicate_state and release
         * or unreference all resources it references
         */
        void (*atomic_destroy_state)(struct drm_plane *plane,
                                     struct drm_plane_state *state);

        /**
         * @atomic_set_property:
         *
         * Decode a driver-private property value and store the decoded value
         * into the passed-in state structure. Since the atomic core decodes all
         * standardized properties (even for extensions beyond the core set of
         * properties which might not be implemented by all drivers) this
         * requires drivers to subclass the state structure.
         *
         * Such driver-private properties should really only be implemented for
         * truly hardware/vendor specific state. Instead it is preferred to
         * standardize atomic extension and decode the properties used to expose
         * such an extension in the core.
         *
         * Do not call this function directly, use
         * drm_atomic_plane_set_property() instead.
         *
         * This callback is optional if the driver does not support any
         * driver-private atomic properties.
         *
         * NOTE:
         *
         * This function is called in the state assembly phase of atomic
         * modesets, which can be aborted for any reason (including on
         * userspace's request to just check whether a configuration would be
         * possible). Drivers MUST NOT touch any persistent state (hardware or
         * software) or data structures except the passed in @state parameter.
         *
         * Also since userspace controls in which order properties are set this
         * function must not do any input validation (since the state update is
         * incomplete and hence likely inconsistent). Instead any such input
         * validation must be done in the various atomic_check callbacks.
         *
         * RETURNS:
         *
         * 0 if the property has been found, -EINVAL if the property isn't
         * implemented by the driver (which shouldn't ever happen, the core only
         * asks for properties attached to this plane). No other validation is
         * allowed by the driver. The core already checks that the property
         * value is within the range (integer, valid enum value, ...) the driver
         * set when registering the property.
         */
        int (*atomic_set_property)(struct drm_plane *plane,
                                   struct drm_plane_state *state,
                                   struct drm_property *property,
                                   uint64_t val);

        /**
         * @atomic_get_property:
         *
         * Reads out the decoded driver-private property. This is used to
         * implement the GETPLANE IOCTL.
         *
         * Do not call this function directly, use
         * drm_atomic_plane_get_property() instead.
         *
         * This callback is optional if the driver does not support any
         * driver-private atomic properties.
         *
         * RETURNS:
         *
         * 0 on success, -EINVAL if the property isn't implemented by the
         * driver (which should never happen, the core only asks for
         * properties attached to this plane).
         */
        int (*atomic_get_property)(struct drm_plane *plane,
                                   const struct drm_plane_state *state,
                                   struct drm_property *property,
                                   uint64_t *val);
        /**
         * @late_register:
         *
         * This optional hook can be used to register additional userspace
         * interfaces attached to the plane like debugfs interfaces.
         * It is called late in the driver load sequence from drm_dev_register().
         * Everything added from this callback should be unregistered in
         * the early_unregister callback.
         *
         * Returns:
         *
         * 0 on success, or a negative error code on failure.
         */
        int (*late_register)(struct drm_plane *plane);

        /**
         * @early_unregister:
         *
         * This optional hook should be used to unregister the additional
         * userspace interfaces attached to the plane from
         * @late_register. It is called from drm_dev_unregister(),
         * early in the driver unload sequence to disable userspace access
         * before data structures are torndown.
         */
        void (*early_unregister)(struct drm_plane *plane);

        /**
         * @atomic_print_state:
         *
         * If driver subclasses &struct drm_plane_state, it should implement
         * this optional hook for printing additional driver specific state.
         *
         * Do not call this directly, use drm_atomic_plane_print_state()
         * instead.
         */
        void (*atomic_print_state)(struct drm_printer *p,
                                   const struct drm_plane_state *state);
};

/**
 * enum drm_plane_type - uapi plane type enumeration
 *
 * For historical reasons not all planes are made the same. This enumeration is
 * used to tell the different types of planes apart to implement the different
 * uapi semantics for them. For userspace which is universal plane aware and
 * which is using that atomic IOCTL there's no difference between these planes
 * (beyong what the driver and hardware can support of course).
 *
 * For compatibility with legacy userspace, only overlay planes are made
 * available to userspace by default. Userspace clients may set the
 * DRM_CLIENT_CAP_UNIVERSAL_PLANES client capability bit to indicate that they
 * wish to receive a universal plane list containing all plane types. See also
 * drm_for_each_legacy_plane().
 *
 * WARNING: The values of this enum is UABI since they're exposed in the "type"
 * property.
 */
enum drm_plane_type {
        /**
         * @DRM_PLANE_TYPE_OVERLAY:
         *
         * Overlay planes represent all non-primary, non-cursor planes. Some
         * drivers refer to these types of planes as "sprites" internally.
         */
        DRM_PLANE_TYPE_OVERLAY,

        /**
         * @DRM_PLANE_TYPE_PRIMARY:
         *
         * Primary planes represent a "main" plane for a CRTC.  Primary planes
         * are the planes operated upon by CRTC modesetting and flipping
         * operations described in the &drm_crtc_funcs.page_flip and
         * &drm_crtc_funcs.set_config hooks.
         */
        DRM_PLANE_TYPE_PRIMARY,

        /**
         * @DRM_PLANE_TYPE_CURSOR:
         *
         * Cursor planes represent a "cursor" plane for a CRTC.  Cursor planes
         * are the planes operated upon by the DRM_IOCTL_MODE_CURSOR and
         * DRM_IOCTL_MODE_CURSOR2 IOCTLs.
         */
        DRM_PLANE_TYPE_CURSOR,
};


/**
 * struct drm_plane - central DRM plane control structure
 * @dev: DRM device this plane belongs to
 * @head: for list management
 * @name: human readable name, can be overwritten by the driver
 * @base: base mode object
 * @possible_crtcs: pipes this plane can be bound to
 * @format_types: array of formats supported by this plane
 * @format_count: number of formats supported
 * @format_default: driver hasn't supplied supported formats for the plane
 * @crtc: currently bound CRTC
 * @fb: currently bound fb
 * @old_fb: Temporary tracking of the old fb while a modeset is ongoing. Used by
 *      drm_mode_set_config_internal() to implement correct refcounting.
 * @funcs: helper functions
 * @properties: property tracking for this plane
 * @type: type of plane (overlay, primary, cursor)
 * @zpos_property: zpos property for this plane
 * @rotation_property: rotation property for this plane
 * @helper_private: mid-layer private data
 */
struct drm_plane {
        struct drm_device *dev;
        struct list_head head;

        char *name;

        /**
         * @mutex:
         *
         * Protects modeset plane state, together with the &drm_crtc.mutex of
         * CRTC this plane is linked to (when active, getting activated or
         * getting disabled).
         *
         * For atomic drivers specifically this protects @state.
         */
        struct drm_modeset_lock mutex;

        struct drm_mode_object base;

        uint32_t possible_crtcs;
        uint32_t *format_types;
        unsigned int format_count;
        bool format_default;

        struct drm_crtc *crtc;
        struct drm_framebuffer *fb;

        struct drm_framebuffer *old_fb;

        const struct drm_plane_funcs *funcs;

        struct drm_object_properties properties;

        enum drm_plane_type type;

        /**
         * @index: Position inside the mode_config.list, can be used as an array
         * index. It is invariant over the lifetime of the plane.
         */
        unsigned index;

        const struct drm_plane_helper_funcs *helper_private;

        /**
         * @state:
         *
         * Current atomic state for this plane.
         *
         * This is protected by @mutex. Note that nonblocking atomic commits
         * access the current plane state without taking locks. Either by going
         * through the &struct drm_atomic_state pointers, see
         * for_each_plane_in_state(), for_each_oldnew_plane_in_state(),
         * for_each_old_plane_in_state() and for_each_new_plane_in_state(). Or
         * through careful ordering of atomic commit operations as implemented
         * in the atomic helpers, see &struct drm_crtc_commit.
         */
        struct drm_plane_state *state;

        struct drm_property *zpos_property;
        struct drm_property *rotation_property;
};

#define obj_to_plane(x) container_of(x, struct drm_plane, base)

__printf(8, 9)
int drm_universal_plane_init(struct drm_device *dev,
                             struct drm_plane *plane,
                             uint32_t possible_crtcs,
                             const struct drm_plane_funcs *funcs,
                             const uint32_t *formats,
                             unsigned int format_count,
                             enum drm_plane_type type,
                             const char *name, ...);
int drm_plane_init(struct drm_device *dev,
                   struct drm_plane *plane,
                   uint32_t possible_crtcs,
                   const struct drm_plane_funcs *funcs,
                   const uint32_t *formats, unsigned int format_count,
                   bool is_primary);
void drm_plane_cleanup(struct drm_plane *plane);

/**
 * drm_plane_index - find the index of a registered plane
 * @plane: plane to find index for
 *
 * Given a registered plane, return the index of that plane within a DRM
 * device's list of planes.
 */
static inline unsigned int drm_plane_index(struct drm_plane *plane)
{
        return plane->index;
}
struct drm_plane * drm_plane_from_index(struct drm_device *dev, int idx);
void drm_plane_force_disable(struct drm_plane *plane);

int drm_mode_plane_set_obj_prop(struct drm_plane *plane,
                                       struct drm_property *property,
                                       uint64_t value);

/**
 * drm_plane_find - find a &drm_plane
 * @dev: DRM device
 * @id: plane id
 *
 * Returns the plane with @id, NULL if it doesn't exist. Simple wrapper around
 * drm_mode_object_find().
 */
static inline struct drm_plane *drm_plane_find(struct drm_device *dev,
                uint32_t id)
{
        struct drm_mode_object *mo;
        mo = drm_mode_object_find(dev, id, DRM_MODE_OBJECT_PLANE);
        return mo ? obj_to_plane(mo) : NULL;
}

/**
 * drm_for_each_plane_mask - iterate over planes specified by bitmask
 * @plane: the loop cursor
 * @dev: the DRM device
 * @plane_mask: bitmask of plane indices
 *
 * Iterate over all planes specified by bitmask.
 */
#define drm_for_each_plane_mask(plane, dev, plane_mask) \
        list_for_each_entry((plane), &(dev)->mode_config.plane_list, head) \
                for_each_if ((plane_mask) & (1 << drm_plane_index(plane)))

/**
 * drm_for_each_legacy_plane - iterate over all planes for legacy userspace
 * @plane: the loop cursor
 * @dev: the DRM device
 *
 * Iterate over all legacy planes of @dev, excluding primary and cursor planes.
 * This is useful for implementing userspace apis when userspace is not
 * universal plane aware. See also &enum drm_plane_type.
 */
#define drm_for_each_legacy_plane(plane, dev) \
        list_for_each_entry(plane, &(dev)->mode_config.plane_list, head) \
                for_each_if (plane->type == DRM_PLANE_TYPE_OVERLAY)

/**
 * drm_for_each_plane - iterate over all planes
 * @plane: the loop cursor
 * @dev: the DRM device
 *
 * Iterate over all planes of @dev, include primary and cursor planes.
 */
#define drm_for_each_plane(plane, dev) \
        list_for_each_entry(plane, &(dev)->mode_config.plane_list, head)


#endif