[linux-2.6-block.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_mode.h>
#include <drm/drm_print.h>
#include <linux/sync_file.h>

#include "drm_crtc_internal.h"
#include "drm_internal.h"

void __drm_crtc_commit_free(struct kref *kref)
{
        struct drm_crtc_commit *commit =
                container_of(kref, struct drm_crtc_commit, ref);

        kfree(commit);
}
EXPORT_SYMBOL(__drm_crtc_commit_free);

/**
 * drm_atomic_state_default_release -
 * release memory initialized by drm_atomic_state_init
 * @state: atomic state
 *
 * Free all the memory allocated by drm_atomic_state_init.
 * This should only be used by drivers which are still subclassing
 * &drm_atomic_state and haven't switched to &drm_private_state yet.
 */
void drm_atomic_state_default_release(struct drm_atomic_state *state)
{
        kfree(state->connectors);
        kfree(state->crtcs);
        kfree(state->planes);
        kfree(state->private_objs);
}
EXPORT_SYMBOL(drm_atomic_state_default_release);

/**
 * drm_atomic_state_init - init new atomic state
 * @dev: DRM device
 * @state: atomic state
 *
 * Default implementation for filling in a new atomic state.
 * This should only be used by drivers which are still subclassing
 * &drm_atomic_state and haven't switched to &drm_private_state yet.
 */
int
drm_atomic_state_init(struct drm_device *dev, struct drm_atomic_state *state)
{
        kref_init(&state->ref);

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

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

        state->dev = dev;

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

        return 0;
fail:
        drm_atomic_state_default_release(state);
        return -ENOMEM;
}
EXPORT_SYMBOL(drm_atomic_state_init);

/**
 * 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_mode_config *config = &dev->mode_config;

        if (!config->funcs->atomic_state_alloc) {
                struct drm_atomic_state *state;

                state = kzalloc(sizeof(*state), GFP_KERNEL);
                if (!state)
                        return NULL;
                if (drm_atomic_state_init(dev, state) < 0) {
                        kfree(state);
                        return NULL;
                }
                return state;
        }

        return config->funcs->atomic_state_alloc(dev);
}
EXPORT_SYMBOL(drm_atomic_state_alloc);

/**
 * drm_atomic_state_default_clear - clear base atomic state
 * @state: atomic state
 *
 * Default implementation for clearing atomic state.
 * This should only be used by drivers which are still subclassing
 * &drm_atomic_state and haven't switched to &drm_private_state yet.
 */
void drm_atomic_state_default_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].ptr;

                if (!connector)
                        continue;

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

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

                if (!crtc)
                        continue;

                crtc->funcs->atomic_destroy_state(crtc,
                                                  state->crtcs[i].state);

                state->crtcs[i].ptr = NULL;
                state->crtcs[i].state = NULL;
        }

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

                if (!plane)
                        continue;

                plane->funcs->atomic_destroy_state(plane,
                                                   state->planes[i].state);
                state->planes[i].ptr = NULL;
                state->planes[i].state = NULL;
        }

        for (i = 0; i < state->num_private_objs; i++) {
                struct drm_private_obj *obj = state->private_objs[i].ptr;

                obj->funcs->atomic_destroy_state(obj,
                                                 state->private_objs[i].state);
                state->private_objs[i].ptr = NULL;
                state->private_objs[i].state = NULL;
        }
        state->num_private_objs = 0;

        if (state->fake_commit) {
                drm_crtc_commit_put(state->fake_commit);
                state->fake_commit = NULL;
        }
}
EXPORT_SYMBOL(drm_atomic_state_default_clear);

/**
 * 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
 * &drm_mode_config_funcs.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;

        if (config->funcs->atomic_state_clear)
                config->funcs->atomic_state_clear(state);
        else
                drm_atomic_state_default_clear(state);
}
EXPORT_SYMBOL(drm_atomic_state_clear);

/**
 * __drm_atomic_state_free - free all memory for an atomic state
 * @ref: This 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 kref *ref)
{
        struct drm_atomic_state *state = container_of(ref, typeof(*state), ref);
        struct drm_mode_config *config = &state->dev->mode_config;

        drm_atomic_state_clear(state);

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

        if (config->funcs->atomic_state_free) {
                config->funcs->atomic_state_free(state);
        } else {
                drm_atomic_state_default_release(state);
                kfree(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 = drm_crtc_index(crtc);
        struct drm_crtc_state *crtc_state;

        WARN_ON(!state->acquire_ctx);

        crtc_state = drm_atomic_get_existing_crtc_state(state, crtc);
        if (crtc_state)
                return crtc_state;

        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->crtcs[index].state = crtc_state;
        state->crtcs[index].old_state = crtc->state;
        state->crtcs[index].new_state = crtc_state;
        state->crtcs[index].ptr = crtc;
        crtc_state->state = state;

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

        return crtc_state;
}
EXPORT_SYMBOL(drm_atomic_get_crtc_state);

static void set_out_fence_for_crtc(struct drm_atomic_state *state,
                                   struct drm_crtc *crtc, s32 __user *fence_ptr)
{
        state->crtcs[drm_crtc_index(crtc)].out_fence_ptr = fence_ptr;
}

static s32 __user *get_out_fence_for_crtc(struct drm_atomic_state *state,
                                          struct drm_crtc *crtc)
{
        s32 __user *fence_ptr;

        fence_ptr = state->crtcs[drm_crtc_index(crtc)].out_fence_ptr;
        state->crtcs[drm_crtc_index(crtc)].out_fence_ptr = NULL;

        return fence_ptr;
}

/**
 * drm_atomic_set_mode_for_crtc - set mode for CRTC
 * @state: the CRTC whose incoming state to update
 * @mode: kernel-internal mode to use for the CRTC, or NULL to disable
 *
 * Set a mode (originating from the kernel) on the desired CRTC state and update
 * the enable property.
 *
 * RETURNS:
 * Zero on success, error code on failure. Cannot return -EDEADLK.
 */
int drm_atomic_set_mode_for_crtc(struct drm_crtc_state *state,
                                 const struct drm_display_mode *mode)
{
        struct drm_crtc *crtc = state->crtc;
        struct drm_mode_modeinfo umode;

        /* Early return for no change. */
        if (mode && memcmp(&state->mode, mode, sizeof(*mode)) == 0)
                return 0;

        drm_property_blob_put(state->mode_blob);
        state->mode_blob = NULL;

        if (mode) {
                drm_mode_convert_to_umode(&umode, mode);
                state->mode_blob =
                        drm_property_create_blob(state->crtc->dev,
                                                 sizeof(umode),
                                                 &umode);
                if (IS_ERR(state->mode_blob))
                        return PTR_ERR(state->mode_blob);

                drm_mode_copy(&state->mode, mode);
                state->enable = true;
                DRM_DEBUG_ATOMIC("Set [MODE:%s] for [CRTC:%d:%s] state %p\n",
                                 mode->name, crtc->base.id, crtc->name, state);
        } else {
                memset(&state->mode, 0, sizeof(state->mode));
                state->enable = false;
                DRM_DEBUG_ATOMIC("Set [NOMODE] for [CRTC:%d:%s] state %p\n",
                                 crtc->base.id, crtc->name, state);
        }

        return 0;
}
EXPORT_SYMBOL(drm_atomic_set_mode_for_crtc);

/**
 * drm_atomic_set_mode_prop_for_crtc - set mode for CRTC
 * @state: the CRTC whose incoming state to update
 * @blob: pointer to blob property to use for mode
 *
 * Set a mode (originating from a blob property) on the desired CRTC state.
 * This function will take a reference on the blob property for the CRTC state,
 * and release the reference held on the state's existing mode property, if any
 * was set.
 *
 * RETURNS:
 * Zero on success, error code on failure. Cannot return -EDEADLK.
 */
int drm_atomic_set_mode_prop_for_crtc(struct drm_crtc_state *state,
                                      struct drm_property_blob *blob)
{
        struct drm_crtc *crtc = state->crtc;

        if (blob == state->mode_blob)
                return 0;

        drm_property_blob_put(state->mode_blob);
        state->mode_blob = NULL;

        memset(&state->mode, 0, sizeof(state->mode));

        if (blob) {
                int ret;

                if (blob->length != sizeof(struct drm_mode_modeinfo)) {
                        DRM_DEBUG_ATOMIC("[CRTC:%d:%s] bad mode blob length: %zu\n",
                                         crtc->base.id, crtc->name,
                                         blob->length);
                        return -EINVAL;
                }

                ret = drm_mode_convert_umode(crtc->dev,
                                             &state->mode, blob->data);
                if (ret) {
                        DRM_DEBUG_ATOMIC("[CRTC:%d:%s] invalid mode (ret=%d, status=%s):\n",
                                         crtc->base.id, crtc->name,
                                         ret, drm_get_mode_status_name(state->mode.status));
                        drm_mode_debug_printmodeline(&state->mode);
                        return -EINVAL;
                }

                state->mode_blob = drm_property_blob_get(blob);
                state->enable = true;
                DRM_DEBUG_ATOMIC("Set [MODE:%s] for [CRTC:%d:%s] state %p\n",
                                 state->mode.name, crtc->base.id, crtc->name,
                                 state);
        } else {
                state->enable = false;
                DRM_DEBUG_ATOMIC("Set [NOMODE] for [CRTC:%d:%s] state %p\n",
                                 crtc->base.id, crtc->name, state);
        }

        return 0;
}
EXPORT_SYMBOL(drm_atomic_set_mode_prop_for_crtc);

/**
 * drm_atomic_replace_property_blob_from_id - lookup the new blob and replace the old one with it
 * @dev: DRM device
 * @blob: a pointer to the member blob to be replaced
 * @blob_id: ID of the new blob
 * @expected_size: total expected size of the blob data (in bytes)
 * @expected_elem_size: expected element size of the blob data (in bytes)
 * @replaced: did the blob get replaced?
 *
 * Replace @blob with another blob with the ID @blob_id. If @blob_id is zero
 * @blob becomes NULL.
 *
 * If @expected_size is positive the new blob length is expected to be equal
 * to @expected_size bytes. If @expected_elem_size is positive the new blob
 * length is expected to be a multiple of @expected_elem_size bytes. Otherwise
 * an error is returned.
 *
 * @replaced will indicate to the caller whether the blob was replaced or not.
 * If the old and new blobs were in fact the same blob @replaced will be false
 * otherwise it will be true.
 *
 * RETURNS:
 * Zero on success, error code on failure.
 */
static int
drm_atomic_replace_property_blob_from_id(struct drm_device *dev,
                                         struct drm_property_blob **blob,
                                         uint64_t blob_id,
                                         ssize_t expected_size,
                                         ssize_t expected_elem_size,
                                         bool *replaced)
{
        struct drm_property_blob *new_blob = NULL;

        if (blob_id != 0) {
                new_blob = drm_property_lookup_blob(dev, blob_id);
                if (new_blob == NULL)
                        return -EINVAL;

                if (expected_size > 0 &&
                    new_blob->length != expected_size) {
                        drm_property_blob_put(new_blob);
                        return -EINVAL;
                }
                if (expected_elem_size > 0 &&
                    new_blob->length % expected_elem_size != 0) {
                        drm_property_blob_put(new_blob);
                        return -EINVAL;
                }
        }

        *replaced |= drm_property_replace_blob(blob, new_blob);
        drm_property_blob_put(new_blob);

        return 0;
}

/**
 * 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
 *
 * This function handles generic/core properties and calls out to driver's
 * &drm_crtc_funcs.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;
        bool replaced = false;
        int ret;

        if (property == config->prop_active)
                state->active = val;
        else if (property == config->prop_mode_id) {
                struct drm_property_blob *mode =
                        drm_property_lookup_blob(dev, val);
                ret = drm_atomic_set_mode_prop_for_crtc(state, mode);
                drm_property_blob_put(mode);
                return ret;
        } else if (property == config->degamma_lut_property) {
                ret = drm_atomic_replace_property_blob_from_id(dev,
                                        &state->degamma_lut,
                                        val,
                                        -1, sizeof(struct drm_color_lut),
                                        &replaced);
                state->color_mgmt_changed |= replaced;
                return ret;
        } else if (property == config->ctm_property) {
                ret = drm_atomic_replace_property_blob_from_id(dev,
                                        &state->ctm,
                                        val,
                                        sizeof(struct drm_color_ctm), -1,
                                        &replaced);
                state->color_mgmt_changed |= replaced;
                return ret;
        } else if (property == config->gamma_lut_property) {
                ret = drm_atomic_replace_property_blob_from_id(dev,
                                        &state->gamma_lut,
                                        val,
                                        -1, sizeof(struct drm_color_lut),
                                        &replaced);
                state->color_mgmt_changed |= replaced;
                return ret;
        } else if (property == config->prop_out_fence_ptr) {
                s32 __user *fence_ptr = u64_to_user_ptr(val);

                if (!fence_ptr)
                        return 0;

                if (put_user(-1, fence_ptr))
                        return -EFAULT;

                set_out_fence_for_crtc(state->state, crtc, fence_ptr);
        } else if (crtc->funcs->atomic_set_property) {
                return crtc->funcs->atomic_set_property(crtc, state, property, val);
        } else {
                DRM_DEBUG_ATOMIC("[CRTC:%d:%s] unknown property [PROP:%d:%s]]\n",
                                 crtc->base.id, crtc->name,
                                 property->base.id, property->name);
                return -EINVAL;
        }

        return 0;
}
EXPORT_SYMBOL(drm_atomic_crtc_set_property);

/**
 * drm_atomic_crtc_get_property - get property value from CRTC state
 * @crtc: the drm CRTC to set a property on
 * @state: the state object to get the property value from
 * @property: the property to set
 * @val: return location for the property value
 *
 * This function handles generic/core properties and calls out to driver's
 * &drm_crtc_funcs.atomic_get_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
 */
static 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 (property == config->prop_mode_id)
                *val = (state->mode_blob) ? state->mode_blob->base.id : 0;
        else if (property == config->degamma_lut_property)
                *val = (state->degamma_lut) ? state->degamma_lut->base.id : 0;
        else if (property == config->ctm_property)
                *val = (state->ctm) ? state->ctm->base.id : 0;
        else if (property == config->gamma_lut_property)
                *val = (state->gamma_lut) ? state->gamma_lut->base.id : 0;
        else if (property == config->prop_out_fence_ptr)
                *val = 0;
        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:%s] active without enabled\n",
                                 crtc->base.id, crtc->name);
                return -EINVAL;
        }

        /* The state->enable vs. state->mode_blob checks can be WARN_ON,
         * as this is a kernel-internal detail that userspace should never
         * be able to trigger. */
        if (drm_core_check_feature(crtc->dev, DRIVER_ATOMIC) &&
            WARN_ON(state->enable && !state->mode_blob)) {
                DRM_DEBUG_ATOMIC("[CRTC:%d:%s] enabled without mode blob\n",
                                 crtc->base.id, crtc->name);
                return -EINVAL;
        }

        if (drm_core_check_feature(crtc->dev, DRIVER_ATOMIC) &&
            WARN_ON(!state->enable && state->mode_blob)) {
                DRM_DEBUG_ATOMIC("[CRTC:%d:%s] disabled with mode blob\n",
                                 crtc->base.id, crtc->name);
                return -EINVAL;
        }

        /*
         * Reject event generation for when a CRTC is off and stays off.
         * It wouldn't be hard to implement this, but userspace has a track
         * record of happily burning through 100% cpu (or worse, crash) when the
         * display pipe is suspended. To avoid all that fun just reject updates
         * that ask for events since likely that indicates a bug in the
         * compositor's drawing loop. This is consistent with the vblank IOCTL
         * and legacy page_flip IOCTL which also reject service on a disabled
         * pipe.
         */
        if (state->event && !state->active && !crtc->state->active) {
                DRM_DEBUG_ATOMIC("[CRTC:%d:%s] requesting event but off\n",
                                 crtc->base.id, crtc->name);
                return -EINVAL;
        }

        return 0;
}

static void drm_atomic_crtc_print_state(struct drm_printer *p,
                const struct drm_crtc_state *state)
{
        struct drm_crtc *crtc = state->crtc;

        drm_printf(p, "crtc[%u]: %s\n", crtc->base.id, crtc->name);
        drm_printf(p, "\tenable=%d\n", state->enable);
        drm_printf(p, "\tactive=%d\n", state->active);
        drm_printf(p, "\tplanes_changed=%d\n", state->planes_changed);
        drm_printf(p, "\tmode_changed=%d\n", state->mode_changed);
        drm_printf(p, "\tactive_changed=%d\n", state->active_changed);
        drm_printf(p, "\tconnectors_changed=%d\n", state->connectors_changed);
        drm_printf(p, "\tcolor_mgmt_changed=%d\n", state->color_mgmt_changed);
        drm_printf(p, "\tplane_mask=%x\n", state->plane_mask);
        drm_printf(p, "\tconnector_mask=%x\n", state->connector_mask);
        drm_printf(p, "\tencoder_mask=%x\n", state->encoder_mask);
        drm_printf(p, "\tmode: " DRM_MODE_FMT "\n", DRM_MODE_ARG(&state->mode));

        if (crtc->funcs->atomic_print_state)
                crtc->funcs->atomic_print_state(p, state);
}

/**
 * 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 = drm_plane_index(plane);
        struct drm_plane_state *plane_state;

        WARN_ON(!state->acquire_ctx);

        /* the legacy pointers should never be set */
        WARN_ON(plane->fb);
        WARN_ON(plane->old_fb);
        WARN_ON(plane->crtc);

        plane_state = drm_atomic_get_existing_plane_state(state, plane);
        if (plane_state)
                return plane_state;

        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->planes[index].state = plane_state;
        state->planes[index].ptr = plane;
        state->planes[index].old_state = plane->state;
        state->planes[index].new_state = plane_state;
        plane_state->state = state;

        DRM_DEBUG_ATOMIC("Added [PLANE:%d:%s] %p state to %p\n",
                         plane->base.id, plane->name, 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
 *
 * This function handles generic/core properties and calls out to driver's
 * &drm_plane_funcs.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
 */
static 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, NULL, val);
                drm_atomic_set_fb_for_plane(state, fb);
                if (fb)
                        drm_framebuffer_put(fb);
        } else if (property == config->prop_in_fence_fd) {
                if (state->fence)
                        return -EINVAL;

                if (U642I64(val) == -1)
                        return 0;

                state->fence = sync_file_get_fence(val);
                if (!state->fence)
                        return -EINVAL;

        } else if (property == config->prop_crtc_id) {
                struct drm_crtc *crtc = drm_crtc_find(dev, NULL, 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 == plane->alpha_property) {
                state->alpha = val;
        } else if (property == plane->rotation_property) {
                if (!is_power_of_2(val & DRM_MODE_ROTATE_MASK)) {
                        DRM_DEBUG_ATOMIC("[PLANE:%d:%s] bad rotation bitmask: 0x%llx\n",
                                         plane->base.id, plane->name, val);
                        return -EINVAL;
                }
                state->rotation = val;
        } else if (property == plane->zpos_property) {
                state->zpos = val;
        } else if (property == plane->color_encoding_property) {
                state->color_encoding = val;
        } else if (property == plane->color_range_property) {
                state->color_range = val;
        } else if (plane->funcs->atomic_set_property) {
                return plane->funcs->atomic_set_property(plane, state,
                                property, val);
        } else {
                DRM_DEBUG_ATOMIC("[PLANE:%d:%s] unknown property [PROP:%d:%s]]\n",
                                 plane->base.id, plane->name,
                                 property->base.id, property->name);
                return -EINVAL;
        }

        return 0;
}

/**
 * drm_atomic_plane_get_property - get property value from plane state
 * @plane: the drm plane to set a property on
 * @state: the state object to get the property value from
 * @property: the property to set
 * @val: return location for the property value
 *
 * This function handles generic/core properties and calls out to driver's
 * &drm_plane_funcs.atomic_get_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
 */
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_in_fence_fd) {
                *val = -1;
        } 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 == plane->alpha_property) {
                *val = state->alpha;
        } else if (property == plane->rotation_property) {
                *val = state->rotation;
        } else if (property == plane->zpos_property) {
                *val = state->zpos;
        } else if (property == plane->color_encoding_property) {
                *val = state->color_encoding;
        } else if (property == plane->color_range_property) {
                *val = state->color_range;
        } else if (plane->funcs->atomic_get_property) {
                return plane->funcs->atomic_get_property(plane, state, property, val);
        } else {
                return -EINVAL;
        }

        return 0;
}

static bool
plane_switching_crtc(struct drm_atomic_state *state,
                     struct drm_plane *plane,
                     struct drm_plane_state *plane_state)
{
        if (!plane->state->crtc || !plane_state->crtc)
                return false;

        if (plane->state->crtc == plane_state->crtc)
                return false;

        /* This could be refined, but currently there's no helper or driver code
         * to implement direct switching of active planes nor userspace to take
         * advantage of more direct plane switching without the intermediate
         * full OFF state.
         */
        return true;
}

/**
 * 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 (state->crtc && !state->fb) {
                DRM_DEBUG_ATOMIC("[PLANE:%d:%s] CRTC set but no FB\n",
                                 plane->base.id, plane->name);
                return -EINVAL;
        } else if (state->fb && !state->crtc) {
                DRM_DEBUG_ATOMIC("[PLANE:%d:%s] FB set but no CRTC\n",
                                 plane->base.id, plane->name);
                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:%d:%s] for [PLANE:%d:%s]\n",
                                 state->crtc->base.id, state->crtc->name,
                                 plane->base.id, plane->name);
                return -EINVAL;
        }

        /* Check whether this plane supports the fb pixel format. */
        ret = drm_plane_check_pixel_format(plane, state->fb->format->format,
                                           state->fb->modifier);
        if (ret) {
                struct drm_format_name_buf format_name;
                DRM_DEBUG_ATOMIC("[PLANE:%d:%s] invalid pixel format %s, modifier 0x%llx\n",
                                 plane->base.id, plane->name,
                                 drm_get_format_name(state->fb->format->format,
                                                     &format_name),
                                 state->fb->modifier);
                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("[PLANE:%d:%s] invalid CRTC coordinates %ux%u+%d+%d\n",
                                 plane->base.id, plane->name,
                                 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("[PLANE:%d:%s] invalid source coordinates "
                                 "%u.%06ux%u.%06u+%u.%06u+%u.%06u (fb %ux%u)\n",
                                 plane->base.id, plane->name,
                                 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,
                                 state->fb->width, state->fb->height);
                return -ENOSPC;
        }

        if (plane_switching_crtc(state->state, plane, state)) {
                DRM_DEBUG_ATOMIC("[PLANE:%d:%s] switching CRTC directly\n",
                                 plane->base.id, plane->name);
                return -EINVAL;
        }

        return 0;
}

static void drm_atomic_plane_print_state(struct drm_printer *p,
                const struct drm_plane_state *state)
{
        struct drm_plane *plane = state->plane;
        struct drm_rect src  = drm_plane_state_src(state);
        struct drm_rect dest = drm_plane_state_dest(state);

        drm_printf(p, "plane[%u]: %s\n", plane->base.id, plane->name);
        drm_printf(p, "\tcrtc=%s\n", state->crtc ? state->crtc->name : "(null)");
        drm_printf(p, "\tfb=%u\n", state->fb ? state->fb->base.id : 0);
        if (state->fb)
                drm_framebuffer_print_info(p, 2, state->fb);
        drm_printf(p, "\tcrtc-pos=" DRM_RECT_FMT "\n", DRM_RECT_ARG(&dest));
        drm_printf(p, "\tsrc-pos=" DRM_RECT_FP_FMT "\n", DRM_RECT_FP_ARG(&src));
        drm_printf(p, "\trotation=%x\n", state->rotation);
        drm_printf(p, "\tcolor-encoding=%s\n",
                   drm_get_color_encoding_name(state->color_encoding));
        drm_printf(p, "\tcolor-range=%s\n",
                   drm_get_color_range_name(state->color_range));

        if (plane->funcs->atomic_print_state)
                plane->funcs->atomic_print_state(p, state);
}

/**
 * DOC: handling driver private state
 *
 * Very often the DRM objects exposed to userspace in the atomic modeset api
 * (&drm_connector, &drm_crtc and &drm_plane) do not map neatly to the
 * underlying hardware. Especially for any kind of shared resources (e.g. shared
 * clocks, scaler units, bandwidth and fifo limits shared among a group of
 * planes or CRTCs, and so on) it makes sense to model these as independent
 * objects. Drivers then need to do similar state tracking and commit ordering for
 * such private (since not exposed to userpace) objects as the atomic core and
 * helpers already provide for connectors, planes and CRTCs.
 *
 * To make this easier on drivers the atomic core provides some support to track
 * driver private state objects using struct &drm_private_obj, with the
 * associated state struct &drm_private_state.
 *
 * Similar to userspace-exposed objects, private state structures can be
 * acquired by calling drm_atomic_get_private_obj_state(). Since this function
 * does not take care of locking, drivers should wrap it for each type of
 * private state object they have with the required call to drm_modeset_lock()
 * for the corresponding &drm_modeset_lock.
 *
 * All private state structures contained in a &drm_atomic_state update can be
 * iterated using for_each_oldnew_private_obj_in_state(),
 * for_each_new_private_obj_in_state() and for_each_old_private_obj_in_state().
 * Drivers are recommended to wrap these for each type of driver private state
 * object they have, filtering on &drm_private_obj.funcs using for_each_if(), at
 * least if they want to iterate over all objects of a given type.
 *
 * An earlier way to handle driver private state was by subclassing struct
 * &drm_atomic_state. But since that encourages non-standard ways to implement
 * the check/commit split atomic requires (by using e.g. "check and rollback or
 * commit instead" of "duplicate state, check, then either commit or release
 * duplicated state) it is deprecated in favour of using &drm_private_state.
 */

/**
 * drm_atomic_private_obj_init - initialize private object
 * @obj: private object
 * @state: initial private object state
 * @funcs: pointer to the struct of function pointers that identify the object
 * type
 *
 * Initialize the private object, which can be embedded into any
 * driver private object that needs its own atomic state.
 */
void
drm_atomic_private_obj_init(struct drm_private_obj *obj,
                            struct drm_private_state *state,
                            const struct drm_private_state_funcs *funcs)
{
        memset(obj, 0, sizeof(*obj));

        obj->state = state;
        obj->funcs = funcs;
}
EXPORT_SYMBOL(drm_atomic_private_obj_init);

/**
 * drm_atomic_private_obj_fini - finalize private object
 * @obj: private object
 *
 * Finalize the private object.
 */
void
drm_atomic_private_obj_fini(struct drm_private_obj *obj)
{
        obj->funcs->atomic_destroy_state(obj, obj->state);
}
EXPORT_SYMBOL(drm_atomic_private_obj_fini);

/**
 * drm_atomic_get_private_obj_state - get private object state
 * @state: global atomic state
 * @obj: private object to get the state for
 *
 * This function returns the private object state for the given private object,
 * allocating the state if needed. It does not grab any locks as the caller is
 * expected to care of any required locking.
 *
 * RETURNS:
 *
 * Either the allocated state or the error code encoded into a pointer.
 */
struct drm_private_state *
drm_atomic_get_private_obj_state(struct drm_atomic_state *state,
                                 struct drm_private_obj *obj)
{
        int index, num_objs, i;
        size_t size;
        struct __drm_private_objs_state *arr;
        struct drm_private_state *obj_state;

        for (i = 0; i < state->num_private_objs; i++)
                if (obj == state->private_objs[i].ptr)
                        return state->private_objs[i].state;

        num_objs = state->num_private_objs + 1;
        size = sizeof(*state->private_objs) * num_objs;
        arr = krealloc(state->private_objs, size, GFP_KERNEL);
        if (!arr)
                return ERR_PTR(-ENOMEM);

        state->private_objs = arr;
        index = state->num_private_objs;
        memset(&state->private_objs[index], 0, sizeof(*state->private_objs));

        obj_state = obj->funcs->atomic_duplicate_state(obj);
        if (!obj_state)
                return ERR_PTR(-ENOMEM);

        state->private_objs[index].state = obj_state;
        state->private_objs[index].old_state = obj->state;
        state->private_objs[index].new_state = obj_state;
        state->private_objs[index].ptr = obj;

        state->num_private_objs = num_objs;

        DRM_DEBUG_ATOMIC("Added new private object %p state %p to %p\n",
                         obj, obj_state, state);

        return obj_state;
}
EXPORT_SYMBOL(drm_atomic_get_private_obj_state);

/**
 * 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;

        WARN_ON(!state->acquire_ctx);

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

        index = drm_connector_index(connector);

        if (index >= state->num_connector) {
                struct __drm_connnectors_state *c;
                int alloc = max(index + 1, config->num_connector);

                c = krealloc(state->connectors, alloc * sizeof(*state->connectors), GFP_KERNEL);
                if (!c)
                        return ERR_PTR(-ENOMEM);

                state->connectors = c;
                memset(&state->connectors[state->num_connector], 0,
                       sizeof(*state->connectors) * (alloc - state->num_connector));

                state->num_connector = alloc;
        }

        if (state->connectors[index].state)
                return state->connectors[index].state;

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

        drm_connector_get(connector);
        state->connectors[index].state = connector_state;
        state->connectors[index].old_state = connector->state;
        state->connectors[index].new_state = connector_state;
        state->connectors[index].ptr = connector;
        connector_state->state = state;

        DRM_DEBUG_ATOMIC("Added [CONNECTOR:%d:%s] %p state to %p\n",
                         connector->base.id, connector->name,
                         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
 *
 * This function handles generic/core properties and calls out to driver's
 * &drm_connector_funcs.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
 */
static 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, NULL, 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 (property == config->tv_select_subconnector_property) {
                state->tv.subconnector = val;
        } else if (property == config->tv_left_margin_property) {
                state->tv.margins.left = val;
        } else if (property == config->tv_right_margin_property) {
                state->tv.margins.right = val;
        } else if (property == config->tv_top_margin_property) {
                state->tv.margins.top = val;
        } else if (property == config->tv_bottom_margin_property) {
                state->tv.margins.bottom = val;
        } else if (property == config->tv_mode_property) {
                state->tv.mode = val;
        } else if (property == config->tv_brightness_property) {
                state->tv.brightness = val;
        } else if (property == config->tv_contrast_property) {
                state->tv.contrast = val;
        } else if (property == config->tv_flicker_reduction_property) {
                state->tv.flicker_reduction = val;
        } else if (property == config->tv_overscan_property) {
                state->tv.overscan = val;
        } else if (property == config->tv_saturation_property) {
                state->tv.saturation = val;
        } else if (property == config->tv_hue_property) {
                state->tv.hue = val;
        } else if (property == config->link_status_property) {
                /* Never downgrade from GOOD to BAD on userspace's request here,
                 * only hw issues can do that.
                 *
                 * For an atomic property the userspace doesn't need to be able
                 * to understand all the properties, but needs to be able to
                 * restore the state it wants on VT switch. So if the userspace
                 * tries to change the link_status from GOOD to BAD, driver
                 * silently rejects it and returns a 0. This prevents userspace
                 * from accidently breaking  the display when it restores the
                 * state.
                 */
                if (state->link_status != DRM_LINK_STATUS_GOOD)
                        state->link_status = val;
        } else if (property == config->aspect_ratio_property) {
                state->picture_aspect_ratio = val;
        } else if (property == config->content_type_property) {
                state->content_type = val;
        } else if (property == connector->scaling_mode_property) {
                state->scaling_mode = val;
        } else if (property == connector->content_protection_property) {
                if (val == DRM_MODE_CONTENT_PROTECTION_ENABLED) {
                        DRM_DEBUG_KMS("only drivers can set CP Enabled\n");
                        return -EINVAL;
                }
                state->content_protection = val;
        } else if (connector->funcs->atomic_set_property) {
                return connector->funcs->atomic_set_property(connector,
                                state, property, val);
        } else {
                DRM_DEBUG_ATOMIC("[CONNECTOR:%d:%s] unknown property [PROP:%d:%s]]\n",
                                 connector->base.id, connector->name,
                                 property->base.id, property->name);
                return -EINVAL;
        }

        return 0;
}

static void drm_atomic_connector_print_state(struct drm_printer *p,
                const struct drm_connector_state *state)
{
        struct drm_connector *connector = state->connector;

        drm_printf(p, "connector[%u]: %s\n", connector->base.id, connector->name);
        drm_printf(p, "\tcrtc=%s\n", state->crtc ? state->crtc->name : "(null)");

        if (connector->funcs->atomic_print_state)
                connector->funcs->atomic_print_state(p, state);
}

/**
 * drm_atomic_connector_get_property - get property value from connector state
 * @connector: the drm connector to set a property on
 * @state: the state object to get the property value from
 * @property: the property to set
 * @val: return location for the property value
 *
 * This function handles generic/core properties and calls out to driver's
 * &drm_connector_funcs.atomic_get_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
 */
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 (property == config->tv_select_subconnector_property) {
                *val = state->tv.subconnector;
        } else if (property == config->tv_left_margin_property) {
                *val = state->tv.margins.left;
        } else if (property == config->tv_right_margin_property) {
                *val = state->tv.margins.right;
        } else if (property == config->tv_top_margin_property) {
                *val = state->tv.margins.top;
        } else if (property == config->tv_bottom_margin_property) {
                *val = state->tv.margins.bottom;
        } else if (property == config->tv_mode_property) {
                *val = state->tv.mode;
        } else if (property == config->tv_brightness_property) {
                *val = state->tv.brightness;
        } else if (property == config->tv_contrast_property) {
                *val = state->tv.contrast;
        } else if (property == config->tv_flicker_reduction_property) {
                *val = state->tv.flicker_reduction;
        } else if (property == config->tv_overscan_property) {
                *val = state->tv.overscan;
        } else if (property == config->tv_saturation_property) {
                *val = state->tv.saturation;
        } else if (property == config->tv_hue_property) {
                *val = state->tv.hue;
        } else if (property == config->link_status_property) {
                *val = state->link_status;
        } else if (property == config->aspect_ratio_property) {
                *val = state->picture_aspect_ratio;
        } else if (property == config->content_type_property) {
                *val = state->content_type;
        } else if (property == connector->scaling_mode_property) {
                *val = state->scaling_mode;
        } else if (property == connector->content_protection_property) {
                *val = state->content_protection;
        } 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;
        /* Nothing to do for same crtc*/
        if (plane_state->crtc == crtc)
                return 0;
        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:%d:%s] state %p to [CRTC:%d:%s]\n",
                                 plane->base.id, plane->name, plane_state,
                                 crtc->base.id, crtc->name);
        else
                DRM_DEBUG_ATOMIC("Link [PLANE:%d:%s] state %p to [NOCRTC]\n",
                                 plane->base.id, plane->name, 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)
{
        struct drm_plane *plane = plane_state->plane;

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

        drm_framebuffer_assign(&plane_state->fb, fb);
}
EXPORT_SYMBOL(drm_atomic_set_fb_for_plane);

/**
 * drm_atomic_set_fence_for_plane - set fence for plane
 * @plane_state: atomic state object for the plane
 * @fence: dma_fence to use for the plane
 *
 * Helper to setup the plane_state fence in case it is not set yet.
 * By using this drivers doesn't need to worry if the user choose
 * implicit or explicit fencing.
 *
 * This function will not set the fence to the state if it was set
 * via explicit fencing interfaces on the atomic ioctl. In that case it will
 * drop the reference to the fence as we are not storing it anywhere.
 * Otherwise, if &drm_plane_state.fence is not set this function we just set it
 * with the received implicit fence. In both cases this function consumes a
 * reference for @fence.
 *
 * This way explicit fencing can be used to overrule implicit fencing, which is
 * important to make explicit fencing use-cases work: One example is using one
 * buffer for 2 screens with different refresh rates. Implicit fencing will
 * clamp rendering to the refresh rate of the slower screen, whereas explicit
 * fence allows 2 independent render and display loops on a single buffer. If a
 * driver allows obeys both implicit and explicit fences for plane updates, then
 * it will break all the benefits of explicit fencing.
 */
void
drm_atomic_set_fence_for_plane(struct drm_plane_state *plane_state,
                               struct dma_fence *fence)
{
        if (plane_state->fence) {
                dma_fence_put(fence);
                return;
        }

        plane_state->fence = fence;
}
EXPORT_SYMBOL(drm_atomic_set_fence_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_connector *connector = conn_state->connector;
        struct drm_crtc_state *crtc_state;

        if (conn_state->crtc == crtc)
                return 0;

        if (conn_state->crtc) {
                crtc_state = drm_atomic_get_new_crtc_state(conn_state->state,
                                                           conn_state->crtc);

                crtc_state->connector_mask &=
                        ~(1 << drm_connector_index(conn_state->connector));

                drm_connector_put(conn_state->connector);
                conn_state->crtc = NULL;
        }

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

                crtc_state->connector_mask |=
                        1 << drm_connector_index(conn_state->connector);

                drm_connector_get(conn_state->connector);
                conn_state->crtc = crtc;

                DRM_DEBUG_ATOMIC("Link [CONNECTOR:%d:%s] state %p to [CRTC:%d:%s]\n",
                                 connector->base.id, connector->name,
                                 conn_state, crtc->base.id, crtc->name);
        } else {
                DRM_DEBUG_ATOMIC("Link [CONNECTOR:%d:%s] state %p to [NOCRTC]\n",
                                 connector->base.id, connector->name,
                                 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;
        struct drm_connector_list_iter conn_iter;
        struct drm_crtc_state *crtc_state;
        int ret;

        crtc_state = drm_atomic_get_crtc_state(state, crtc);
        if (IS_ERR(crtc_state))
                return PTR_ERR(crtc_state);

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

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

        /*
         * Changed connectors are already in @state, so only need to look
         * at the connector_mask in crtc_state.
         */
        drm_connector_list_iter_begin(state->dev, &conn_iter);
        drm_for_each_connector_iter(connector, &conn_iter) {
                if (!(crtc_state->connector_mask & (1 << drm_connector_index(connector))))
                        continue;

                conn_state = drm_atomic_get_connector_state(state, connector);
                if (IS_ERR(conn_state)) {
                        drm_connector_list_iter_end(&conn_iter);
                        return PTR_ERR(conn_state);
                }
        }
        drm_connector_list_iter_end(&conn_iter);

        return 0;
}
EXPORT_SYMBOL(drm_atomic_add_affected_connectors);

/**
 * drm_atomic_add_affected_planes - add planes for crtc
 * @state: atomic state
 * @crtc: DRM crtc
 *
 * This function walks the current configuration and adds all planes
 * currently used by @crtc to the atomic configuration @state. This is useful
 * when an atomic commit also needs to check all currently enabled plane on
 * @crtc, e.g. when changing the mode. It's also useful when re-enabling a CRTC
 * to avoid special code to force-enable all planes.
 *
 * Since acquiring a plane state will always also acquire the w/w mutex of the
 * current CRTC for that plane (if there is any) adding all the plane states for
 * a CRTC will not reduce parallism of atomic updates.
 *
 * 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_planes(struct drm_atomic_state *state,
                               struct drm_crtc *crtc)
{
        struct drm_plane *plane;

        WARN_ON(!drm_atomic_get_new_crtc_state(state, crtc));

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

        drm_for_each_plane_mask(plane, state->dev, crtc->state->plane_mask) {
                struct drm_plane_state *plane_state =
                        drm_atomic_get_plane_state(state, plane);

                if (IS_ERR(plane_state))
                        return PTR_ERR(plane_state);
        }
        return 0;
}
EXPORT_SYMBOL(drm_atomic_add_affected_planes);

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

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

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

        if (ret)
                return ret;

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

        return 0;
}
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.
 *
 * This function will take its own reference on @state.
 * Callers should always release their reference with drm_atomic_state_put().
 *
 * 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("committing %p\n", state);

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

/**
 * drm_atomic_nonblocking_commit - atomic nonblocking 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.
 *
 * This function will take its own reference on @state.
 * Callers should always release their reference with drm_atomic_state_put().
 *
 * Returns:
 * 0 on success, negative error code on failure.
 */
int drm_atomic_nonblocking_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("committing %p nonblocking\n", state);

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

static void drm_atomic_print_state(const struct drm_atomic_state *state)
{
        struct drm_printer p = drm_info_printer(state->dev->dev);
        struct drm_plane *plane;
        struct drm_plane_state *plane_state;
        struct drm_crtc *crtc;
        struct drm_crtc_state *crtc_state;
        struct drm_connector *connector;
        struct drm_connector_state *connector_state;
        int i;

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

        for_each_new_plane_in_state(state, plane, plane_state, i)
                drm_atomic_plane_print_state(&p, plane_state);

        for_each_new_crtc_in_state(state, crtc, crtc_state, i)
                drm_atomic_crtc_print_state(&p, crtc_state);

        for_each_new_connector_in_state(state, connector, connector_state, i)
                drm_atomic_connector_print_state(&p, connector_state);
}

static void __drm_state_dump(struct drm_device *dev, struct drm_printer *p,
                             bool take_locks)
{
        struct drm_mode_config *config = &dev->mode_config;
        struct drm_plane *plane;
        struct drm_crtc *crtc;
        struct drm_connector *connector;
        struct drm_connector_list_iter conn_iter;

        if (!drm_core_check_feature(dev, DRIVER_ATOMIC))
                return;

        list_for_each_entry(plane, &config->plane_list, head) {
                if (take_locks)
                        drm_modeset_lock(&plane->mutex, NULL);
                drm_atomic_plane_print_state(p, plane->state);
                if (take_locks)
                        drm_modeset_unlock(&plane->mutex);
        }

        list_for_each_entry(crtc, &config->crtc_list, head) {
                if (take_locks)
                        drm_modeset_lock(&crtc->mutex, NULL);
                drm_atomic_crtc_print_state(p, crtc->state);
                if (take_locks)
                        drm_modeset_unlock(&crtc->mutex);
        }

        drm_connector_list_iter_begin(dev, &conn_iter);
        if (take_locks)
                drm_modeset_lock(&dev->mode_config.connection_mutex, NULL);
        drm_for_each_connector_iter(connector, &conn_iter)
                drm_atomic_connector_print_state(p, connector->state);
        if (take_locks)
                drm_modeset_unlock(&dev->mode_config.connection_mutex);
        drm_connector_list_iter_end(&conn_iter);
}

/**
 * drm_state_dump - dump entire device atomic state
 * @dev: the drm device
 * @p: where to print the state to
 *
 * Just for debugging.  Drivers might want an option to dump state
 * to dmesg in case of error irq's.  (Hint, you probably want to
 * ratelimit this!)
 *
 * The caller must drm_modeset_lock_all(), or if this is called
 * from error irq handler, it should not be enabled by default.
 * (Ie. if you are debugging errors you might not care that this
 * is racey.  But calling this without all modeset locks held is
 * not inherently safe.)
 */
void drm_state_dump(struct drm_device *dev, struct drm_printer *p)
{
        __drm_state_dump(dev, p, false);
}
EXPORT_SYMBOL(drm_state_dump);

#ifdef CONFIG_DEBUG_FS
static int drm_state_info(struct seq_file *m, void *data)
{
        struct drm_info_node *node = (struct drm_info_node *) m->private;
        struct drm_device *dev = node->minor->dev;
        struct drm_printer p = drm_seq_file_printer(m);

        __drm_state_dump(dev, &p, true);

        return 0;
}

/* any use in debugfs files to dump individual planes/crtc/etc? */
static const struct drm_info_list drm_atomic_debugfs_list[] = {
        {"state", drm_state_info, 0},
};

int drm_atomic_debugfs_init(struct drm_minor *minor)
{
        return drm_debugfs_create_files(drm_atomic_debugfs_list,
                        ARRAY_SIZE(drm_atomic_debugfs_list),
                        minor->debugfs_root, minor);
}
#endif

/*
 * The big monster ioctl
 */

static struct drm_pending_vblank_event *create_vblank_event(
                struct drm_crtc *crtc, uint64_t user_data)
{
        struct drm_pending_vblank_event *e = NULL;

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

        e->event.base.type = DRM_EVENT_FLIP_COMPLETE;
        e->event.base.length = sizeof(e->event);
        e->event.vbl.crtc_id = crtc->base.id;
        e->event.vbl.user_data = user_data;

        return e;
}

int drm_atomic_connector_commit_dpms(struct drm_atomic_state *state,
                                     struct drm_connector *connector,
                                     int mode)
{
        struct drm_connector *tmp_connector;
        struct drm_connector_state *new_conn_state;
        struct drm_crtc *crtc;
        struct drm_crtc_state *crtc_state;
        int i, ret, old_mode = connector->dpms;
        bool active = false;

        ret = drm_modeset_lock(&state->dev->mode_config.connection_mutex,
                               state->acquire_ctx);
        if (ret)
                return ret;

        if (mode != DRM_MODE_DPMS_ON)
                mode = DRM_MODE_DPMS_OFF;
        connector->dpms = mode;

        crtc = connector->state->crtc;
        if (!crtc)
                goto out;
        ret = drm_atomic_add_affected_connectors(state, crtc);
        if (ret)
                goto out;

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

        for_each_new_connector_in_state(state, tmp_connector, new_conn_state, i) {
                if (new_conn_state->crtc != crtc)
                        continue;
                if (tmp_connector->dpms == DRM_MODE_DPMS_ON) {
                        active = true;
                        break;
                }
        }

        crtc_state->active = active;
        ret = drm_atomic_commit(state);
out:
        if (ret != 0)
                connector->dpms = old_mode;
        return ret;
}

int drm_atomic_set_property(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;
}

/**
 * DOC: explicit fencing properties
 *
 * Explicit fencing allows userspace to control the buffer synchronization
 * between devices. A Fence or a group of fences are transfered to/from
 * userspace using Sync File fds and there are two DRM properties for that.
 * IN_FENCE_FD on each DRM Plane to send fences to the kernel and
 * OUT_FENCE_PTR on each DRM CRTC to receive fences from the kernel.
 *
 * As a contrast, with implicit fencing the kernel keeps track of any
 * ongoing rendering, and automatically ensures that the atomic update waits
 * for any pending rendering to complete. For shared buffers represented with
 * a &struct dma_buf this is tracked in &struct reservation_object.
 * Implicit syncing is how Linux traditionally worked (e.g. DRI2/3 on X.org),
 * whereas explicit fencing is what Android wants.
 *
 * "IN_FENCE_FD”:
 *      Use this property to pass a fence that DRM should wait on before
 *      proceeding with the Atomic Commit request and show the framebuffer for
 *      the plane on the screen. The fence can be either a normal fence or a
 *      merged one, the sync_file framework will handle both cases and use a
 *      fence_array if a merged fence is received. Passing -1 here means no
 *      fences to wait on.
 *
 *      If the Atomic Commit request has the DRM_MODE_ATOMIC_TEST_ONLY flag
 *      it will only check if the Sync File is a valid one.
 *
 *      On the driver side the fence is stored on the @fence parameter of
 *      &struct drm_plane_state. Drivers which also support implicit fencing
 *      should set the implicit fence using drm_atomic_set_fence_for_plane(),
 *      to make sure there's consistent behaviour between drivers in precedence
 *      of implicit vs. explicit fencing.
 *
 * "OUT_FENCE_PTR”:
 *      Use this property to pass a file descriptor pointer to DRM. Once the
 *      Atomic Commit request call returns OUT_FENCE_PTR will be filled with
 *      the file descriptor number of a Sync File. This Sync File contains the
 *      CRTC fence that will be signaled when all framebuffers present on the
 *      Atomic Commit * request for that given CRTC are scanned out on the
 *      screen.
 *
 *      The Atomic Commit request fails if a invalid pointer is passed. If the
 *      Atomic Commit request fails for any other reason the out fence fd
 *      returned will be -1. On a Atomic Commit with the
 *      DRM_MODE_ATOMIC_TEST_ONLY flag the out fence will also be set to -1.
 *
 *      Note that out-fences don't have a special interface to drivers and are
 *      internally represented by a &struct drm_pending_vblank_event in struct
 *      &drm_crtc_state, which is also used by the nonblocking atomic commit
 *      helpers and for the DRM event handling for existing userspace.
 */

struct drm_out_fence_state {
        s32 __user *out_fence_ptr;
        struct sync_file *sync_file;
        int fd;
};

static int setup_out_fence(struct drm_out_fence_state *fence_state,
                           struct dma_fence *fence)
{
        fence_state->fd = get_unused_fd_flags(O_CLOEXEC);
        if (fence_state->fd < 0)
                return fence_state->fd;

        if (put_user(fence_state->fd, fence_state->out_fence_ptr))
                return -EFAULT;

        fence_state->sync_file = sync_file_create(fence);
        if (!fence_state->sync_file)
                return -ENOMEM;

        return 0;
}

static int prepare_crtc_signaling(struct drm_device *dev,
                                  struct drm_atomic_state *state,
                                  struct drm_mode_atomic *arg,
                                  struct drm_file *file_priv,
                                  struct drm_out_fence_state **fence_state,
                                  unsigned int *num_fences)
{
        struct drm_crtc *crtc;
        struct drm_crtc_state *crtc_state;
        int i, c = 0, ret;

        if (arg->flags & DRM_MODE_ATOMIC_TEST_ONLY)
                return 0;

        for_each_new_crtc_in_state(state, crtc, crtc_state, i) {
                s32 __user *fence_ptr;

                fence_ptr = get_out_fence_for_crtc(crtc_state->state, crtc);

                if (arg->flags & DRM_MODE_PAGE_FLIP_EVENT || fence_ptr) {
                        struct drm_pending_vblank_event *e;

                        e = create_vblank_event(crtc, arg->user_data);
                        if (!e)
                                return -ENOMEM;

                        crtc_state->event = e;
                }

                if (arg->flags & DRM_MODE_PAGE_FLIP_EVENT) {
                        struct drm_pending_vblank_event *e = crtc_state->event;

                        if (!file_priv)
                                continue;

                        ret = drm_event_reserve_init(dev, file_priv, &e->base,
                                                     &e->event.base);
                        if (ret) {
                                kfree(e);
                                crtc_state->event = NULL;
                                return ret;
                        }
                }

                if (fence_ptr) {
                        struct dma_fence *fence;
                        struct drm_out_fence_state *f;

                        f = krealloc(*fence_state, sizeof(**fence_state) *
                                     (*num_fences + 1), GFP_KERNEL);
                        if (!f)
                                return -ENOMEM;

                        memset(&f[*num_fences], 0, sizeof(*f));

                        f[*num_fences].out_fence_ptr = fence_ptr;
                        *fence_state = f;

                        fence = drm_crtc_create_fence(crtc);
                        if (!fence)
                                return -ENOMEM;

                        ret = setup_out_fence(&f[(*num_fences)++], fence);
                        if (ret) {
                                dma_fence_put(fence);
                                return ret;
                        }

                        crtc_state->event->base.fence = fence;
                }

                c++;
        }

        /*
         * Having this flag means user mode pends on event which will never
         * reach due to lack of at least one CRTC for signaling
         */
        if (c == 0 && (arg->flags & DRM_MODE_PAGE_FLIP_EVENT))
                return -EINVAL;

        return 0;
}

static void complete_crtc_signaling(struct drm_device *dev,
                                    struct drm_atomic_state *state,
                                    struct drm_out_fence_state *fence_state,
                                    unsigned int num_fences,
                                    bool install_fds)
{
        struct drm_crtc *crtc;
        struct drm_crtc_state *crtc_state;
        int i;

        if (install_fds) {
                for (i = 0; i < num_fences; i++)
                        fd_install(fence_state[i].fd,
                                   fence_state[i].sync_file->file);

                kfree(fence_state);
                return;
        }

        for_each_new_crtc_in_state(state, crtc, crtc_state, i) {
                struct drm_pending_vblank_event *event = crtc_state->event;
                /*
                 * Free the allocated event. drm_atomic_helper_setup_commit
                 * can allocate an event too, so only free it if it's ours
                 * to prevent a double free in drm_atomic_state_clear.
                 */
                if (event && (event->base.fence || event->base.file_priv)) {
                        drm_event_cancel_free(dev, &event->base);
                        crtc_state->event = NULL;
                }
        }

        if (!fence_state)
                return;

        for (i = 0; i < num_fences; i++) {
                if (fence_state[i].sync_file)
                        fput(fence_state[i].sync_file->file);
                if (fence_state[i].fd >= 0)
                        put_unused_fd(fence_state[i].fd);

                /* If this fails log error to the user */
                if (fence_state[i].out_fence_ptr &&
                    put_user(-1, fence_state[i].out_fence_ptr))
                        DRM_DEBUG_ATOMIC("Couldn't clear out_fence_ptr\n");
        }

        kfree(fence_state);
}

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_out_fence_state *fence_state;
        int ret = 0;
        unsigned int i, j, num_fences;

        /* 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, DRM_MODESET_ACQUIRE_INTERRUPTIBLE);

        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;
        fence_state = NULL;
        num_fences = 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 out;
                }

                obj = drm_mode_object_find(dev, file_priv, obj_id, DRM_MODE_OBJECT_ANY);
                if (!obj) {
                        ret = -ENOENT;
                        goto out;
                }

                if (!obj->properties) {
                        drm_mode_object_put(obj);
                        ret = -ENOENT;
                        goto out;
                }

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

                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)) {
                                drm_mode_object_put(obj);
                                ret = -EFAULT;
                                goto out;
                        }

                        prop = drm_mode_obj_find_prop_id(obj, prop_id);
                        if (!prop) {
                                drm_mode_object_put(obj);
                                ret = -ENOENT;
                                goto out;
                        }

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

                        ret = drm_atomic_set_property(state, obj, prop,
                                                      prop_value);
                        if (ret) {
                                drm_mode_object_put(obj);
                                goto out;
                        }

                        copied_props++;
                }

                drm_mode_object_put(obj);
        }

        ret = prepare_crtc_signaling(dev, state, arg, file_priv, &fence_state,
                                     &num_fences);
        if (ret)
                goto out;

        if (arg->flags & DRM_MODE_ATOMIC_TEST_ONLY) {
                ret = drm_atomic_check_only(state);
        } else if (arg->flags & DRM_MODE_ATOMIC_NONBLOCK) {
                ret = drm_atomic_nonblocking_commit(state);
        } else {
                if (unlikely(drm_debug & DRM_UT_STATE))
                        drm_atomic_print_state(state);

                ret = drm_atomic_commit(state);
        }

out:
        complete_crtc_signaling(dev, state, fence_state, num_fences, !ret);

        if (ret == -EDEADLK) {
                drm_atomic_state_clear(state);
                ret = drm_modeset_backoff(&ctx);
                if (!ret)
                        goto retry;
        }

        drm_atomic_state_put(state);

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

        return ret;
}