Linux 4.1.16

[linux/fpc-iii.git] / drivers / gpu / drm / drm_atomic.c

/*
 * Copyright (C) 2014 Red Hat
 * Copyright (C) 2014 Intel Corp.
 *
 * 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 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
 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) 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.
 *
 * Authors:
 * Rob Clark <robdclark@gmail.com>
 * Daniel Vetter <daniel.vetter@ffwll.ch>
 */


#include <drm/drmP.h>
#include <drm/drm_atomic.h>
#include <drm/drm_plane_helper.h>

static void kfree_state(struct drm_atomic_state *state)
{
        kfree(state->connectors);
        kfree(state->connector_states);
        kfree(state->crtcs);
        kfree(state->crtc_states);
        kfree(state->planes);
        kfree(state->plane_states);
        kfree(state);
}

/**
 * drm_atomic_state_alloc - allocate atomic state
 * @dev: DRM device
 *
 * This allocates an empty atomic state to track updates.
 */
struct drm_atomic_state *
drm_atomic_state_alloc(struct drm_device *dev)
{
        struct drm_atomic_state *state;

        state = kzalloc(sizeof(*state), GFP_KERNEL);
        if (!state)
                return NULL;

        /* TODO legacy paths should maybe do a better job about
         * setting this appropriately?
         */
        state->allow_modeset = true;

        state->num_connector = ACCESS_ONCE(dev->mode_config.num_connector);

        state->crtcs = kcalloc(dev->mode_config.num_crtc,
                               sizeof(*state->crtcs), GFP_KERNEL);
        if (!state->crtcs)
                goto fail;
        state->crtc_states = kcalloc(dev->mode_config.num_crtc,
                                     sizeof(*state->crtc_states), GFP_KERNEL);
        if (!state->crtc_states)
                goto fail;
        state->planes = kcalloc(dev->mode_config.num_total_plane,
                                sizeof(*state->planes), GFP_KERNEL);
        if (!state->planes)
                goto fail;
        state->plane_states = kcalloc(dev->mode_config.num_total_plane,
                                      sizeof(*state->plane_states), GFP_KERNEL);
        if (!state->plane_states)
                goto fail;
        state->connectors = kcalloc(state->num_connector,
                                    sizeof(*state->connectors),
                                    GFP_KERNEL);
        if (!state->connectors)
                goto fail;
        state->connector_states = kcalloc(state->num_connector,
                                          sizeof(*state->connector_states),
                                          GFP_KERNEL);
        if (!state->connector_states)
                goto fail;

        state->dev = dev;

        DRM_DEBUG_ATOMIC("Allocate atomic state %p\n", state);

        return state;
fail:
        kfree_state(state);

        return NULL;
}
EXPORT_SYMBOL(drm_atomic_state_alloc);

/**
 * drm_atomic_state_clear - clear state object
 * @state: atomic state
 *
 * When the w/w mutex algorithm detects a deadlock we need to back off and drop
 * all locks. So someone else could sneak in and change the current modeset
 * configuration. Which means that all the state assembled in @state is no
 * longer an atomic update to the current state, but to some arbitrary earlier
 * state. Which could break assumptions the driver's ->atomic_check likely
 * relies on.
 *
 * Hence we must clear all cached state and completely start over, using this
 * function.
 */
void drm_atomic_state_clear(struct drm_atomic_state *state)
{
        struct drm_device *dev = state->dev;
        struct drm_mode_config *config = &dev->mode_config;
        int i;

        DRM_DEBUG_ATOMIC("Clearing atomic state %p\n", state);

        for (i = 0; i < state->num_connector; i++) {
                struct drm_connector *connector = state->connectors[i];

                if (!connector)
                        continue;

                WARN_ON(!drm_modeset_is_locked(&config->connection_mutex));

                connector->funcs->atomic_destroy_state(connector,
                                                       state->connector_states[i]);
                state->connectors[i] = NULL;
                state->connector_states[i] = NULL;
        }

        for (i = 0; i < config->num_crtc; i++) {
                struct drm_crtc *crtc = state->crtcs[i];

                if (!crtc)
                        continue;

                crtc->funcs->atomic_destroy_state(crtc,
                                                  state->crtc_states[i]);
                state->crtcs[i] = NULL;
                state->crtc_states[i] = NULL;
        }

        for (i = 0; i < config->num_total_plane; i++) {
                struct drm_plane *plane = state->planes[i];

                if (!plane)
                        continue;

                plane->funcs->atomic_destroy_state(plane,
                                                   state->plane_states[i]);
                state->planes[i] = NULL;
                state->plane_states[i] = NULL;
        }
}
EXPORT_SYMBOL(drm_atomic_state_clear);

/**
 * drm_atomic_state_free - free all memory for an atomic state
 * @state: atomic state to deallocate
 *
 * This frees all memory associated with an atomic state, including all the
 * per-object state for planes, crtcs and connectors.
 */
void drm_atomic_state_free(struct drm_atomic_state *state)
{
        if (!state)
                return;

        drm_atomic_state_clear(state);

        DRM_DEBUG_ATOMIC("Freeing atomic state %p\n", state);

        kfree_state(state);
}
EXPORT_SYMBOL(drm_atomic_state_free);

/**
 * drm_atomic_get_crtc_state - get crtc state
 * @state: global atomic state object
 * @crtc: crtc to get state object for
 *
 * This function returns the crtc state for the given crtc, allocating it if
 * needed. It will also grab the relevant crtc lock to make sure that the state
 * is consistent.
 *
 * Returns:
 *
 * Either the allocated state or the error code encoded into the pointer. When
 * the error is EDEADLK then the w/w mutex code has detected a deadlock and the
 * entire atomic sequence must be restarted. All other errors are fatal.
 */
struct drm_crtc_state *
drm_atomic_get_crtc_state(struct drm_atomic_state *state,
                          struct drm_crtc *crtc)
{
        int ret, index;
        struct drm_crtc_state *crtc_state;

        index = drm_crtc_index(crtc);

        if (state->crtc_states[index])
                return state->crtc_states[index];

        ret = drm_modeset_lock(&crtc->mutex, state->acquire_ctx);
        if (ret)
                return ERR_PTR(ret);

        crtc_state = crtc->funcs->atomic_duplicate_state(crtc);
        if (!crtc_state)
                return ERR_PTR(-ENOMEM);

        state->crtc_states[index] = crtc_state;
        state->crtcs[index] = crtc;
        crtc_state->state = state;

        DRM_DEBUG_ATOMIC("Added [CRTC:%d] %p state to %p\n",
                         crtc->base.id, crtc_state, state);

        return crtc_state;
}
EXPORT_SYMBOL(drm_atomic_get_crtc_state);

/**
 * drm_atomic_crtc_set_property - set property on CRTC
 * @crtc: the drm CRTC to set a property on
 * @state: the state object to update with the new property value
 * @property: the property to set
 * @val: the new property value
 *
 * Use this instead of calling crtc->atomic_set_property directly.
 * This function handles generic/core properties and calls out to
 * driver's ->atomic_set_property() for driver properties.  To ensure
 * consistent behavior you must call this function rather than the
 * driver hook directly.
 *
 * RETURNS:
 * Zero on success, error code on failure
 */
int drm_atomic_crtc_set_property(struct drm_crtc *crtc,
                struct drm_crtc_state *state, struct drm_property *property,
                uint64_t val)
{
        struct drm_device *dev = crtc->dev;
        struct drm_mode_config *config = &dev->mode_config;

        /* FIXME: Mode prop is missing, which also controls ->enable. */
        if (property == config->prop_active)
                state->active = val;
        else if (crtc->funcs->atomic_set_property)
                return crtc->funcs->atomic_set_property(crtc, state, property, val);
        else
                return -EINVAL;

        return 0;
}
EXPORT_SYMBOL(drm_atomic_crtc_set_property);

/*
 * This function handles generic/core properties and calls out to
 * driver's ->atomic_get_property() for driver properties.  To ensure
 * consistent behavior you must call this function rather than the
 * driver hook directly.
 */
int drm_atomic_crtc_get_property(struct drm_crtc *crtc,
                const struct drm_crtc_state *state,
                struct drm_property *property, uint64_t *val)
{
        struct drm_device *dev = crtc->dev;
        struct drm_mode_config *config = &dev->mode_config;

        if (property == config->prop_active)
                *val = state->active;
        else if (crtc->funcs->atomic_get_property)
                return crtc->funcs->atomic_get_property(crtc, state, property, val);
        else
                return -EINVAL;

        return 0;
}

/**
 * drm_atomic_crtc_check - check crtc state
 * @crtc: crtc to check
 * @state: crtc state to check
 *
 * Provides core sanity checks for crtc state.
 *
 * RETURNS:
 * Zero on success, error code on failure
 */
static int drm_atomic_crtc_check(struct drm_crtc *crtc,
                struct drm_crtc_state *state)
{
        /* NOTE: we explicitly don't enforce constraints such as primary
         * layer covering entire screen, since that is something we want
         * to allow (on hw that supports it).  For hw that does not, it
         * should be checked in driver's crtc->atomic_check() vfunc.
         *
         * TODO: Add generic modeset state checks once we support those.
         */

        if (state->active && !state->enable) {
                DRM_DEBUG_ATOMIC("[CRTC:%d] active without enabled\n",
                                 crtc->base.id);
                return -EINVAL;
        }

        return 0;
}

/**
 * drm_atomic_get_plane_state - get plane state
 * @state: global atomic state object
 * @plane: plane to get state object for
 *
 * This function returns the plane state for the given plane, allocating it if
 * needed. It will also grab the relevant plane lock to make sure that the state
 * is consistent.
 *
 * Returns:
 *
 * Either the allocated state or the error code encoded into the pointer. When
 * the error is EDEADLK then the w/w mutex code has detected a deadlock and the
 * entire atomic sequence must be restarted. All other errors are fatal.
 */
struct drm_plane_state *
drm_atomic_get_plane_state(struct drm_atomic_state *state,
                          struct drm_plane *plane)
{
        int ret, index;
        struct drm_plane_state *plane_state;

        index = drm_plane_index(plane);

        if (state->plane_states[index])
                return state->plane_states[index];

        ret = drm_modeset_lock(&plane->mutex, state->acquire_ctx);
        if (ret)
                return ERR_PTR(ret);

        plane_state = plane->funcs->atomic_duplicate_state(plane);
        if (!plane_state)
                return ERR_PTR(-ENOMEM);

        state->plane_states[index] = plane_state;
        state->planes[index] = plane;
        plane_state->state = state;

        DRM_DEBUG_ATOMIC("Added [PLANE:%d] %p state to %p\n",
                         plane->base.id, plane_state, state);

        if (plane_state->crtc) {
                struct drm_crtc_state *crtc_state;

                crtc_state = drm_atomic_get_crtc_state(state,
                                                       plane_state->crtc);
                if (IS_ERR(crtc_state))
                        return ERR_CAST(crtc_state);
        }

        return plane_state;
}
EXPORT_SYMBOL(drm_atomic_get_plane_state);

/**
 * drm_atomic_plane_set_property - set property on plane
 * @plane: the drm plane to set a property on
 * @state: the state object to update with the new property value
 * @property: the property to set
 * @val: the new property value
 *
 * Use this instead of calling plane->atomic_set_property directly.
 * This function handles generic/core properties and calls out to
 * driver's ->atomic_set_property() for driver properties.  To ensure
 * consistent behavior you must call this function rather than the
 * driver hook directly.
 *
 * RETURNS:
 * Zero on success, error code on failure
 */
int drm_atomic_plane_set_property(struct drm_plane *plane,
                struct drm_plane_state *state, struct drm_property *property,
                uint64_t val)
{
        struct drm_device *dev = plane->dev;
        struct drm_mode_config *config = &dev->mode_config;

        if (property == config->prop_fb_id) {
                struct drm_framebuffer *fb = drm_framebuffer_lookup(dev, val);
                drm_atomic_set_fb_for_plane(state, fb);
                if (fb)
                        drm_framebuffer_unreference(fb);
        } else if (property == config->prop_crtc_id) {
                struct drm_crtc *crtc = drm_crtc_find(dev, val);
                return drm_atomic_set_crtc_for_plane(state, crtc);
        } else if (property == config->prop_crtc_x) {
                state->crtc_x = U642I64(val);
        } else if (property == config->prop_crtc_y) {
                state->crtc_y = U642I64(val);
        } else if (property == config->prop_crtc_w) {
                state->crtc_w = val;
        } else if (property == config->prop_crtc_h) {
                state->crtc_h = val;
        } else if (property == config->prop_src_x) {
                state->src_x = val;
        } else if (property == config->prop_src_y) {
                state->src_y = val;
        } else if (property == config->prop_src_w) {
                state->src_w = val;
        } else if (property == config->prop_src_h) {
                state->src_h = val;
        } else if (property == config->rotation_property) {
                state->rotation = val;
        } else if (plane->funcs->atomic_set_property) {
                return plane->funcs->atomic_set_property(plane, state,
                                property, val);
        } else {
                return -EINVAL;
        }

        return 0;
}
EXPORT_SYMBOL(drm_atomic_plane_set_property);

/*
 * This function handles generic/core properties and calls out to
 * driver's ->atomic_get_property() for driver properties.  To ensure
 * consistent behavior you must call this function rather than the
 * driver hook directly.
 */
static int
drm_atomic_plane_get_property(struct drm_plane *plane,
                const struct drm_plane_state *state,
                struct drm_property *property, uint64_t *val)
{
        struct drm_device *dev = plane->dev;
        struct drm_mode_config *config = &dev->mode_config;

        if (property == config->prop_fb_id) {
                *val = (state->fb) ? state->fb->base.id : 0;
        } else if (property == config->prop_crtc_id) {
                *val = (state->crtc) ? state->crtc->base.id : 0;
        } else if (property == config->prop_crtc_x) {
                *val = I642U64(state->crtc_x);
        } else if (property == config->prop_crtc_y) {
                *val = I642U64(state->crtc_y);
        } else if (property == config->prop_crtc_w) {
                *val = state->crtc_w;
        } else if (property == config->prop_crtc_h) {
                *val = state->crtc_h;
        } else if (property == config->prop_src_x) {
                *val = state->src_x;
        } else if (property == config->prop_src_y) {
                *val = state->src_y;
        } else if (property == config->prop_src_w) {
                *val = state->src_w;
        } else if (property == config->prop_src_h) {
                *val = state->src_h;
        } else if (property == config->rotation_property) {
                *val = state->rotation;
        } else if (plane->funcs->atomic_get_property) {
                return plane->funcs->atomic_get_property(plane, state, property, val);
        } else {
                return -EINVAL;
        }

        return 0;
}

/**
 * drm_atomic_plane_check - check plane state
 * @plane: plane to check
 * @state: plane state to check
 *
 * Provides core sanity checks for plane state.
 *
 * RETURNS:
 * Zero on success, error code on failure
 */
static int drm_atomic_plane_check(struct drm_plane *plane,
                struct drm_plane_state *state)
{
        unsigned int fb_width, fb_height;
        int ret;

        /* either *both* CRTC and FB must be set, or neither */
        if (WARN_ON(state->crtc && !state->fb)) {
                DRM_DEBUG_ATOMIC("CRTC set but no FB\n");
                return -EINVAL;
        } else if (WARN_ON(state->fb && !state->crtc)) {
                DRM_DEBUG_ATOMIC("FB set but no CRTC\n");
                return -EINVAL;
        }

        /* if disabled, we don't care about the rest of the state: */
        if (!state->crtc)
                return 0;

        /* Check whether this plane is usable on this CRTC */
        if (!(plane->possible_crtcs & drm_crtc_mask(state->crtc))) {
                DRM_DEBUG_ATOMIC("Invalid crtc for plane\n");
                return -EINVAL;
        }

        /* Check whether this plane supports the fb pixel format. */
        ret = drm_plane_check_pixel_format(plane, state->fb->pixel_format);
        if (ret) {
                DRM_DEBUG_ATOMIC("Invalid pixel format %s\n",
                                 drm_get_format_name(state->fb->pixel_format));
                return ret;
        }

        /* Give drivers some help against integer overflows */
        if (state->crtc_w > INT_MAX ||
            state->crtc_x > INT_MAX - (int32_t) state->crtc_w ||
            state->crtc_h > INT_MAX ||
            state->crtc_y > INT_MAX - (int32_t) state->crtc_h) {
                DRM_DEBUG_ATOMIC("Invalid CRTC coordinates %ux%u+%d+%d\n",
                                 state->crtc_w, state->crtc_h,
                                 state->crtc_x, state->crtc_y);
                return -ERANGE;
        }

        fb_width = state->fb->width << 16;
        fb_height = state->fb->height << 16;

        /* Make sure source coordinates are inside the fb. */
        if (state->src_w > fb_width ||
            state->src_x > fb_width - state->src_w ||
            state->src_h > fb_height ||
            state->src_y > fb_height - state->src_h) {
                DRM_DEBUG_ATOMIC("Invalid source coordinates "
                                 "%u.%06ux%u.%06u+%u.%06u+%u.%06u\n",
                                 state->src_w >> 16, ((state->src_w & 0xffff) * 15625) >> 10,
                                 state->src_h >> 16, ((state->src_h & 0xffff) * 15625) >> 10,
                                 state->src_x >> 16, ((state->src_x & 0xffff) * 15625) >> 10,
                                 state->src_y >> 16, ((state->src_y & 0xffff) * 15625) >> 10);
                return -ENOSPC;
        }

        return 0;
}

/**
 * drm_atomic_get_connector_state - get connector state
 * @state: global atomic state object
 * @connector: connector to get state object for
 *
 * This function returns the connector state for the given connector,
 * allocating it if needed. It will also grab the relevant connector lock to
 * make sure that the state is consistent.
 *
 * Returns:
 *
 * Either the allocated state or the error code encoded into the pointer. When
 * the error is EDEADLK then the w/w mutex code has detected a deadlock and the
 * entire atomic sequence must be restarted. All other errors are fatal.
 */
struct drm_connector_state *
drm_atomic_get_connector_state(struct drm_atomic_state *state,
                          struct drm_connector *connector)
{
        int ret, index;
        struct drm_mode_config *config = &connector->dev->mode_config;
        struct drm_connector_state *connector_state;

        ret = drm_modeset_lock(&config->connection_mutex, state->acquire_ctx);
        if (ret)
                return ERR_PTR(ret);

        index = drm_connector_index(connector);

        /*
         * Construction of atomic state updates can race with a connector
         * hot-add which might overflow. In this case flip the table and just
         * restart the entire ioctl - no one is fast enough to livelock a cpu
         * with physical hotplug events anyway.
         *
         * Note that we only grab the indexes once we have the right lock to
         * prevent hotplug/unplugging of connectors. So removal is no problem,
         * at most the array is a bit too large.
         */
        if (index >= state->num_connector) {
                DRM_DEBUG_ATOMIC("Hot-added connector would overflow state array, restarting\n");
                return ERR_PTR(-EAGAIN);
        }

        if (state->connector_states[index])
                return state->connector_states[index];

        connector_state = connector->funcs->atomic_duplicate_state(connector);
        if (!connector_state)
                return ERR_PTR(-ENOMEM);

        state->connector_states[index] = connector_state;
        state->connectors[index] = connector;
        connector_state->state = state;

        DRM_DEBUG_ATOMIC("Added [CONNECTOR:%d] %p state to %p\n",
                         connector->base.id, connector_state, state);

        if (connector_state->crtc) {
                struct drm_crtc_state *crtc_state;

                crtc_state = drm_atomic_get_crtc_state(state,
                                                       connector_state->crtc);
                if (IS_ERR(crtc_state))
                        return ERR_CAST(crtc_state);
        }

        return connector_state;
}
EXPORT_SYMBOL(drm_atomic_get_connector_state);

/**
 * drm_atomic_connector_set_property - set property on connector.
 * @connector: the drm connector to set a property on
 * @state: the state object to update with the new property value
 * @property: the property to set
 * @val: the new property value
 *
 * Use this instead of calling connector->atomic_set_property directly.
 * This function handles generic/core properties and calls out to
 * driver's ->atomic_set_property() for driver properties.  To ensure
 * consistent behavior you must call this function rather than the
 * driver hook directly.
 *
 * RETURNS:
 * Zero on success, error code on failure
 */
int drm_atomic_connector_set_property(struct drm_connector *connector,
                struct drm_connector_state *state, struct drm_property *property,
                uint64_t val)
{
        struct drm_device *dev = connector->dev;
        struct drm_mode_config *config = &dev->mode_config;

        if (property == config->prop_crtc_id) {
                struct drm_crtc *crtc = drm_crtc_find(dev, val);
                return drm_atomic_set_crtc_for_connector(state, crtc);
        } else if (property == config->dpms_property) {
                /* setting DPMS property requires special handling, which
                 * is done in legacy setprop path for us.  Disallow (for
                 * now?) atomic writes to DPMS property:
                 */
                return -EINVAL;
        } else if (connector->funcs->atomic_set_property) {
                return connector->funcs->atomic_set_property(connector,
                                state, property, val);
        } else {
                return -EINVAL;
        }
}
EXPORT_SYMBOL(drm_atomic_connector_set_property);

/*
 * This function handles generic/core properties and calls out to
 * driver's ->atomic_get_property() for driver properties.  To ensure
 * consistent behavior you must call this function rather than the
 * driver hook directly.
 */
static int
drm_atomic_connector_get_property(struct drm_connector *connector,
                const struct drm_connector_state *state,
                struct drm_property *property, uint64_t *val)
{
        struct drm_device *dev = connector->dev;
        struct drm_mode_config *config = &dev->mode_config;

        if (property == config->prop_crtc_id) {
                *val = (state->crtc) ? state->crtc->base.id : 0;
        } else if (property == config->dpms_property) {
                *val = connector->dpms;
        } else if (connector->funcs->atomic_get_property) {
                return connector->funcs->atomic_get_property(connector,
                                state, property, val);
        } else {
                return -EINVAL;
        }

        return 0;
}

int drm_atomic_get_property(struct drm_mode_object *obj,
                struct drm_property *property, uint64_t *val)
{
        struct drm_device *dev = property->dev;
        int ret;

        switch (obj->type) {
        case DRM_MODE_OBJECT_CONNECTOR: {
                struct drm_connector *connector = obj_to_connector(obj);
                WARN_ON(!drm_modeset_is_locked(&dev->mode_config.connection_mutex));
                ret = drm_atomic_connector_get_property(connector,
                                connector->state, property, val);
                break;
        }
        case DRM_MODE_OBJECT_CRTC: {
                struct drm_crtc *crtc = obj_to_crtc(obj);
                WARN_ON(!drm_modeset_is_locked(&crtc->mutex));
                ret = drm_atomic_crtc_get_property(crtc,
                                crtc->state, property, val);
                break;
        }
        case DRM_MODE_OBJECT_PLANE: {
                struct drm_plane *plane = obj_to_plane(obj);
                WARN_ON(!drm_modeset_is_locked(&plane->mutex));
                ret = drm_atomic_plane_get_property(plane,
                                plane->state, property, val);
                break;
        }
        default:
                ret = -EINVAL;
                break;
        }

        return ret;
}

/**
 * drm_atomic_set_crtc_for_plane - set crtc for plane
 * @plane_state: the plane whose incoming state to update
 * @crtc: crtc to use for the plane
 *
 * Changing the assigned crtc for a plane requires us to grab the lock and state
 * for the new crtc, as needed. This function takes care of all these details
 * besides updating the pointer in the state object itself.
 *
 * Returns:
 * 0 on success or can fail with -EDEADLK or -ENOMEM. When the error is EDEADLK
 * then the w/w mutex code has detected a deadlock and the entire atomic
 * sequence must be restarted. All other errors are fatal.
 */
int
drm_atomic_set_crtc_for_plane(struct drm_plane_state *plane_state,
                              struct drm_crtc *crtc)
{
        struct drm_plane *plane = plane_state->plane;
        struct drm_crtc_state *crtc_state;

        if (plane_state->crtc) {
                crtc_state = drm_atomic_get_crtc_state(plane_state->state,
                                                       plane_state->crtc);
                if (WARN_ON(IS_ERR(crtc_state)))
                        return PTR_ERR(crtc_state);

                crtc_state->plane_mask &= ~(1 << drm_plane_index(plane));
        }

        plane_state->crtc = crtc;

        if (crtc) {
                crtc_state = drm_atomic_get_crtc_state(plane_state->state,
                                                       crtc);
                if (IS_ERR(crtc_state))
                        return PTR_ERR(crtc_state);
                crtc_state->plane_mask |= (1 << drm_plane_index(plane));
        }

        if (crtc)
                DRM_DEBUG_ATOMIC("Link plane state %p to [CRTC:%d]\n",
                                 plane_state, crtc->base.id);
        else
                DRM_DEBUG_ATOMIC("Link plane state %p to [NOCRTC]\n",
                                 plane_state);

        return 0;
}
EXPORT_SYMBOL(drm_atomic_set_crtc_for_plane);

/**
 * drm_atomic_set_fb_for_plane - set framebuffer for plane
 * @plane_state: atomic state object for the plane
 * @fb: fb to use for the plane
 *
 * Changing the assigned framebuffer for a plane requires us to grab a reference
 * to the new fb and drop the reference to the old fb, if there is one. This
 * function takes care of all these details besides updating the pointer in the
 * state object itself.
 */
void
drm_atomic_set_fb_for_plane(struct drm_plane_state *plane_state,
                            struct drm_framebuffer *fb)
{
        if (plane_state->fb)
                drm_framebuffer_unreference(plane_state->fb);
        if (fb)
                drm_framebuffer_reference(fb);
        plane_state->fb = fb;

        if (fb)
                DRM_DEBUG_ATOMIC("Set [FB:%d] for plane state %p\n",
                                 fb->base.id, plane_state);
        else
                DRM_DEBUG_ATOMIC("Set [NOFB] for plane state %p\n",
                                 plane_state);
}
EXPORT_SYMBOL(drm_atomic_set_fb_for_plane);

/**
 * drm_atomic_set_crtc_for_connector - set crtc for connector
 * @conn_state: atomic state object for the connector
 * @crtc: crtc to use for the connector
 *
 * Changing the assigned crtc for a connector requires us to grab the lock and
 * state for the new crtc, as needed. This function takes care of all these
 * details besides updating the pointer in the state object itself.
 *
 * Returns:
 * 0 on success or can fail with -EDEADLK or -ENOMEM. When the error is EDEADLK
 * then the w/w mutex code has detected a deadlock and the entire atomic
 * sequence must be restarted. All other errors are fatal.
 */
int
drm_atomic_set_crtc_for_connector(struct drm_connector_state *conn_state,
                                  struct drm_crtc *crtc)
{
        struct drm_crtc_state *crtc_state;

        if (crtc) {
                crtc_state = drm_atomic_get_crtc_state(conn_state->state, crtc);
                if (IS_ERR(crtc_state))
                        return PTR_ERR(crtc_state);
        }

        conn_state->crtc = crtc;

        if (crtc)
                DRM_DEBUG_ATOMIC("Link connector state %p to [CRTC:%d]\n",
                                 conn_state, crtc->base.id);
        else
                DRM_DEBUG_ATOMIC("Link connector state %p to [NOCRTC]\n",
                                 conn_state);

        return 0;
}
EXPORT_SYMBOL(drm_atomic_set_crtc_for_connector);

/**
 * drm_atomic_add_affected_connectors - add connectors for crtc
 * @state: atomic state
 * @crtc: DRM crtc
 *
 * This function walks the current configuration and adds all connectors
 * currently using @crtc to the atomic configuration @state. Note that this
 * function must acquire the connection mutex. This can potentially cause
 * unneeded seralization if the update is just for the planes on one crtc. Hence
 * drivers and helpers should only call this when really needed (e.g. when a
 * full modeset needs to happen due to some change).
 *
 * Returns:
 * 0 on success or can fail with -EDEADLK or -ENOMEM. When the error is EDEADLK
 * then the w/w mutex code has detected a deadlock and the entire atomic
 * sequence must be restarted. All other errors are fatal.
 */
int
drm_atomic_add_affected_connectors(struct drm_atomic_state *state,
                                   struct drm_crtc *crtc)
{
        struct drm_mode_config *config = &state->dev->mode_config;
        struct drm_connector *connector;
        struct drm_connector_state *conn_state;
        int ret;

        ret = drm_modeset_lock(&config->connection_mutex, state->acquire_ctx);
        if (ret)
                return ret;

        DRM_DEBUG_ATOMIC("Adding all current connectors for [CRTC:%d] to %p\n",
                         crtc->base.id, state);

        /*
         * Changed connectors are already in @state, so only need to look at the
         * current configuration.
         */
        list_for_each_entry(connector, &config->connector_list, head) {
                if (connector->state->crtc != crtc)
                        continue;

                conn_state = drm_atomic_get_connector_state(state, connector);
                if (IS_ERR(conn_state))
                        return PTR_ERR(conn_state);
        }

        return 0;
}
EXPORT_SYMBOL(drm_atomic_add_affected_connectors);

/**
 * drm_atomic_connectors_for_crtc - count number of connected outputs
 * @state: atomic state
 * @crtc: DRM crtc
 *
 * This function counts all connectors which will be connected to @crtc
 * according to @state. Useful to recompute the enable state for @crtc.
 */
int
drm_atomic_connectors_for_crtc(struct drm_atomic_state *state,
                               struct drm_crtc *crtc)
{
        struct drm_connector *connector;
        struct drm_connector_state *conn_state;

        int i, num_connected_connectors = 0;

        for_each_connector_in_state(state, connector, conn_state, i) {
                if (conn_state->crtc == crtc)
                        num_connected_connectors++;
        }

        DRM_DEBUG_ATOMIC("State %p has %i connectors for [CRTC:%d]\n",
                         state, num_connected_connectors, crtc->base.id);

        return num_connected_connectors;
}
EXPORT_SYMBOL(drm_atomic_connectors_for_crtc);

/**
 * drm_atomic_legacy_backoff - locking backoff for legacy ioctls
 * @state: atomic state
 *
 * This function should be used by legacy entry points which don't understand
 * -EDEADLK semantics. For simplicity this one will grab all modeset locks after
 * the slowpath completed.
 */
void drm_atomic_legacy_backoff(struct drm_atomic_state *state)
{
        int ret;

retry:
        drm_modeset_backoff(state->acquire_ctx);

        ret = drm_modeset_lock(&state->dev->mode_config.connection_mutex,
                               state->acquire_ctx);
        if (ret)
                goto retry;
        ret = drm_modeset_lock_all_crtcs(state->dev,
                                         state->acquire_ctx);
        if (ret)
                goto retry;
}
EXPORT_SYMBOL(drm_atomic_legacy_backoff);

/**
 * drm_atomic_check_only - check whether a given config would work
 * @state: atomic configuration to check
 *
 * Note that this function can return -EDEADLK if the driver needed to acquire
 * more locks but encountered a deadlock. The caller must then do the usual w/w
 * backoff dance and restart. All other errors are fatal.
 *
 * Returns:
 * 0 on success, negative error code on failure.
 */
int drm_atomic_check_only(struct drm_atomic_state *state)
{
        struct drm_device *dev = state->dev;
        struct drm_mode_config *config = &dev->mode_config;
        struct drm_plane *plane;
        struct drm_plane_state *plane_state;
        struct drm_crtc *crtc;
        struct drm_crtc_state *crtc_state;
        int i, ret = 0;

        DRM_DEBUG_ATOMIC("checking %p\n", state);

        for_each_plane_in_state(state, plane, plane_state, i) {
                ret = drm_atomic_plane_check(plane, plane_state);
                if (ret) {
                        DRM_DEBUG_ATOMIC("[PLANE:%d] atomic core check failed\n",
                                         plane->base.id);
                        return ret;
                }
        }

        for_each_crtc_in_state(state, crtc, crtc_state, i) {
                ret = drm_atomic_crtc_check(crtc, crtc_state);
                if (ret) {
                        DRM_DEBUG_ATOMIC("[CRTC:%d] atomic core check failed\n",
                                         crtc->base.id);
                        return ret;
                }
        }

        if (config->funcs->atomic_check)
                ret = config->funcs->atomic_check(state->dev, state);

        if (!state->allow_modeset) {
                for_each_crtc_in_state(state, crtc, crtc_state, i) {
                        if (crtc_state->mode_changed ||
                            crtc_state->active_changed) {
                                DRM_DEBUG_ATOMIC("[CRTC:%d] requires full modeset\n",
                                                 crtc->base.id);
                                return -EINVAL;
                        }
                }
        }

        return ret;
}
EXPORT_SYMBOL(drm_atomic_check_only);

/**
 * drm_atomic_commit - commit configuration atomically
 * @state: atomic configuration to check
 *
 * Note that this function can return -EDEADLK if the driver needed to acquire
 * more locks but encountered a deadlock. The caller must then do the usual w/w
 * backoff dance and restart. All other errors are fatal.
 *
 * Also note that on successful execution ownership of @state is transferred
 * from the caller of this function to the function itself. The caller must not
 * free or in any other way access @state. If the function fails then the caller
 * must clean up @state itself.
 *
 * Returns:
 * 0 on success, negative error code on failure.
 */
int drm_atomic_commit(struct drm_atomic_state *state)
{
        struct drm_mode_config *config = &state->dev->mode_config;
        int ret;

        ret = drm_atomic_check_only(state);
        if (ret)
                return ret;

        DRM_DEBUG_ATOMIC("commiting %p\n", state);

        return config->funcs->atomic_commit(state->dev, state, false);
}
EXPORT_SYMBOL(drm_atomic_commit);

/**
 * drm_atomic_async_commit - atomic&async configuration commit
 * @state: atomic configuration to check
 *
 * Note that this function can return -EDEADLK if the driver needed to acquire
 * more locks but encountered a deadlock. The caller must then do the usual w/w
 * backoff dance and restart. All other errors are fatal.
 *
 * Also note that on successful execution ownership of @state is transferred
 * from the caller of this function to the function itself. The caller must not
 * free or in any other way access @state. If the function fails then the caller
 * must clean up @state itself.
 *
 * Returns:
 * 0 on success, negative error code on failure.
 */
int drm_atomic_async_commit(struct drm_atomic_state *state)
{
        struct drm_mode_config *config = &state->dev->mode_config;
        int ret;

        ret = drm_atomic_check_only(state);
        if (ret)
                return ret;

        DRM_DEBUG_ATOMIC("commiting %p asynchronously\n", state);

        return config->funcs->atomic_commit(state->dev, state, true);
}
EXPORT_SYMBOL(drm_atomic_async_commit);

/*
 * The big monstor ioctl
 */

static struct drm_pending_vblank_event *create_vblank_event(
                struct drm_device *dev, struct drm_file *file_priv, uint64_t user_data)
{
        struct drm_pending_vblank_event *e = NULL;
        unsigned long flags;

        spin_lock_irqsave(&dev->event_lock, flags);
        if (file_priv->event_space < sizeof e->event) {
                spin_unlock_irqrestore(&dev->event_lock, flags);
                goto out;
        }
        file_priv->event_space -= sizeof e->event;
        spin_unlock_irqrestore(&dev->event_lock, flags);

        e = kzalloc(sizeof *e, GFP_KERNEL);
        if (e == NULL) {
                spin_lock_irqsave(&dev->event_lock, flags);
                file_priv->event_space += sizeof e->event;
                spin_unlock_irqrestore(&dev->event_lock, flags);
                goto out;
        }

        e->event.base.type = DRM_EVENT_FLIP_COMPLETE;
        e->event.base.length = sizeof e->event;
        e->event.user_data = user_data;
        e->base.event = &e->event.base;
        e->base.file_priv = file_priv;
        e->base.destroy = (void (*) (struct drm_pending_event *)) kfree;

out:
        return e;
}

static void destroy_vblank_event(struct drm_device *dev,
                struct drm_file *file_priv, struct drm_pending_vblank_event *e)
{
        unsigned long flags;

        spin_lock_irqsave(&dev->event_lock, flags);
        file_priv->event_space += sizeof e->event;
        spin_unlock_irqrestore(&dev->event_lock, flags);
        kfree(e);
}

static int atomic_set_prop(struct drm_atomic_state *state,
                struct drm_mode_object *obj, struct drm_property *prop,
                uint64_t prop_value)
{
        struct drm_mode_object *ref;
        int ret;

        if (!drm_property_change_valid_get(prop, prop_value, &ref))
                return -EINVAL;

        switch (obj->type) {
        case DRM_MODE_OBJECT_CONNECTOR: {
                struct drm_connector *connector = obj_to_connector(obj);
                struct drm_connector_state *connector_state;

                connector_state = drm_atomic_get_connector_state(state, connector);
                if (IS_ERR(connector_state)) {
                        ret = PTR_ERR(connector_state);
                        break;
                }

                ret = drm_atomic_connector_set_property(connector,
                                connector_state, prop, prop_value);
                break;
        }
        case DRM_MODE_OBJECT_CRTC: {
                struct drm_crtc *crtc = obj_to_crtc(obj);
                struct drm_crtc_state *crtc_state;

                crtc_state = drm_atomic_get_crtc_state(state, crtc);
                if (IS_ERR(crtc_state)) {
                        ret = PTR_ERR(crtc_state);
                        break;
                }

                ret = drm_atomic_crtc_set_property(crtc,
                                crtc_state, prop, prop_value);
                break;
        }
        case DRM_MODE_OBJECT_PLANE: {
                struct drm_plane *plane = obj_to_plane(obj);
                struct drm_plane_state *plane_state;

                plane_state = drm_atomic_get_plane_state(state, plane);
                if (IS_ERR(plane_state)) {
                        ret = PTR_ERR(plane_state);
                        break;
                }

                ret = drm_atomic_plane_set_property(plane,
                                plane_state, prop, prop_value);
                break;
        }
        default:
                ret = -EINVAL;
                break;
        }

        drm_property_change_valid_put(prop, ref);
        return ret;
}

int drm_mode_atomic_ioctl(struct drm_device *dev,
                          void *data, struct drm_file *file_priv)
{
        struct drm_mode_atomic *arg = data;
        uint32_t __user *objs_ptr = (uint32_t __user *)(unsigned long)(arg->objs_ptr);
        uint32_t __user *count_props_ptr = (uint32_t __user *)(unsigned long)(arg->count_props_ptr);
        uint32_t __user *props_ptr = (uint32_t __user *)(unsigned long)(arg->props_ptr);
        uint64_t __user *prop_values_ptr = (uint64_t __user *)(unsigned long)(arg->prop_values_ptr);
        unsigned int copied_objs, copied_props;
        struct drm_atomic_state *state;
        struct drm_modeset_acquire_ctx ctx;
        struct drm_plane *plane;
        struct drm_crtc *crtc;
        struct drm_crtc_state *crtc_state;
        unsigned plane_mask = 0;
        int ret = 0;
        unsigned int i, j;

        /* disallow for drivers not supporting atomic: */
        if (!drm_core_check_feature(dev, DRIVER_ATOMIC))
                return -EINVAL;

        /* disallow for userspace that has not enabled atomic cap (even
         * though this may be a bit overkill, since legacy userspace
         * wouldn't know how to call this ioctl)
         */
        if (!file_priv->atomic)
                return -EINVAL;

        if (arg->flags & ~DRM_MODE_ATOMIC_FLAGS)
                return -EINVAL;

        if (arg->reserved)
                return -EINVAL;

        if ((arg->flags & DRM_MODE_PAGE_FLIP_ASYNC) &&
                        !dev->mode_config.async_page_flip)
                return -EINVAL;

        /* can't test and expect an event at the same time. */
        if ((arg->flags & DRM_MODE_ATOMIC_TEST_ONLY) &&
                        (arg->flags & DRM_MODE_PAGE_FLIP_EVENT))
                return -EINVAL;

        drm_modeset_acquire_init(&ctx, 0);

        state = drm_atomic_state_alloc(dev);
        if (!state)
                return -ENOMEM;

        state->acquire_ctx = &ctx;
        state->allow_modeset = !!(arg->flags & DRM_MODE_ATOMIC_ALLOW_MODESET);

retry:
        copied_objs = 0;
        copied_props = 0;

        for (i = 0; i < arg->count_objs; i++) {
                uint32_t obj_id, count_props;
                struct drm_mode_object *obj;

                if (get_user(obj_id, objs_ptr + copied_objs)) {
                        ret = -EFAULT;
                        goto fail;
                }

                obj = drm_mode_object_find(dev, obj_id, DRM_MODE_OBJECT_ANY);
                if (!obj || !obj->properties) {
                        ret = -ENOENT;
                        goto fail;
                }

                if (obj->type == DRM_MODE_OBJECT_PLANE) {
                        plane = obj_to_plane(obj);
                        plane_mask |= (1 << drm_plane_index(plane));
                        plane->old_fb = plane->fb;
                }

                if (get_user(count_props, count_props_ptr + copied_objs)) {
                        ret = -EFAULT;
                        goto fail;
                }

                copied_objs++;

                for (j = 0; j < count_props; j++) {
                        uint32_t prop_id;
                        uint64_t prop_value;
                        struct drm_property *prop;

                        if (get_user(prop_id, props_ptr + copied_props)) {
                                ret = -EFAULT;
                                goto fail;
                        }

                        prop = drm_property_find(dev, prop_id);
                        if (!prop) {
                                ret = -ENOENT;
                                goto fail;
                        }

                        if (copy_from_user(&prop_value,
                                           prop_values_ptr + copied_props,
                                           sizeof(prop_value))) {
                                ret = -EFAULT;
                                goto fail;
                        }

                        ret = atomic_set_prop(state, obj, prop, prop_value);
                        if (ret)
                                goto fail;

                        copied_props++;
                }
        }

        if (arg->flags & DRM_MODE_PAGE_FLIP_EVENT) {
                for_each_crtc_in_state(state, crtc, crtc_state, i) {
                        struct drm_pending_vblank_event *e;

                        e = create_vblank_event(dev, file_priv, arg->user_data);
                        if (!e) {
                                ret = -ENOMEM;
                                goto fail;
                        }

                        crtc_state->event = e;
                }
        }

        if (arg->flags & DRM_MODE_ATOMIC_TEST_ONLY) {
                ret = drm_atomic_check_only(state);
                /* _check_only() does not free state, unlike _commit() */
                drm_atomic_state_free(state);
        } else if (arg->flags & DRM_MODE_ATOMIC_NONBLOCK) {
                ret = drm_atomic_async_commit(state);
        } else {
                ret = drm_atomic_commit(state);
        }

        /* if succeeded, fixup legacy plane crtc/fb ptrs before dropping
         * locks (ie. while it is still safe to deref plane->state).  We
         * need to do this here because the driver entry points cannot
         * distinguish between legacy and atomic ioctls.
         */
        drm_for_each_plane_mask(plane, dev, plane_mask) {
                if (ret == 0) {
                        struct drm_framebuffer *new_fb = plane->state->fb;
                        if (new_fb)
                                drm_framebuffer_reference(new_fb);
                        plane->fb = new_fb;
                        plane->crtc = plane->state->crtc;
                } else {
                        plane->old_fb = NULL;
                }
                if (plane->old_fb) {
                        drm_framebuffer_unreference(plane->old_fb);
                        plane->old_fb = NULL;
                }
        }

        drm_modeset_drop_locks(&ctx);
        drm_modeset_acquire_fini(&ctx);

        return ret;

fail:
        if (ret == -EDEADLK)
                goto backoff;

        if (arg->flags & DRM_MODE_PAGE_FLIP_EVENT) {
                for_each_crtc_in_state(state, crtc, crtc_state, i) {
                        destroy_vblank_event(dev, file_priv, crtc_state->event);
                        crtc_state->event = NULL;
                }
        }

        drm_atomic_state_free(state);

        drm_modeset_drop_locks(&ctx);
        drm_modeset_acquire_fini(&ctx);

        return ret;

backoff:
        drm_atomic_state_clear(state);
        drm_modeset_backoff(&ctx);

        goto retry;
}