[mirror_ubuntu-eoan-kernel.git] / drivers / gpu / drm / i915 / intel_atomic.c

/*
 * Copyright © 2015 Intel Corporation
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS 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.
 */

/**
 * DOC: atomic modeset support
 *
 * The functions here implement the state management and hardware programming
 * dispatch required by the atomic modeset infrastructure.
 * See intel_atomic_plane.c for the plane-specific atomic functionality.
 */

#include <drm/drmP.h>
#include <drm/drm_atomic.h>
#include <drm/drm_atomic_helper.h>
#include <drm/drm_plane_helper.h>
#include "intel_drv.h"


/**
 * intel_atomic_check - validate state object
 * @dev: drm device
 * @state: state to validate
 */
int intel_atomic_check(struct drm_device *dev,
		       struct drm_atomic_state *state)
{
	int nplanes = dev->mode_config.num_total_plane;
	int ncrtcs = dev->mode_config.num_crtc;
	int nconnectors = dev->mode_config.num_connector;
	enum pipe nuclear_pipe = INVALID_PIPE;
	struct intel_crtc *nuclear_crtc = NULL;
	struct intel_crtc_state *crtc_state = NULL;
	int ret;
	int i;
	bool not_nuclear = false;

	/*
	 * FIXME:  At the moment, we only support "nuclear pageflip" on a
	 * single CRTC.  Cross-crtc updates will be added later.
	 */
	for (i = 0; i < nplanes; i++) {
		struct intel_plane *plane = to_intel_plane(state->planes[i]);
		if (!plane)
			continue;

		if (nuclear_pipe == INVALID_PIPE) {
			nuclear_pipe = plane->pipe;
		} else if (nuclear_pipe != plane->pipe) {
			DRM_DEBUG_KMS("i915 only support atomic plane operations on a single CRTC at the moment\n");
			return -EINVAL;
		}
	}

	/*
	 * FIXME:  We only handle planes for now; make sure there are no CRTC's
	 * or connectors involved.
	 */
	state->allow_modeset = false;
	for (i = 0; i < ncrtcs; i++) {
		struct intel_crtc *crtc = to_intel_crtc(state->crtcs[i]);
		if (crtc)
			memset(&crtc->atomic, 0, sizeof(crtc->atomic));
		if (crtc && crtc->pipe != nuclear_pipe)
			not_nuclear = true;
		if (crtc && crtc->pipe == nuclear_pipe) {
			nuclear_crtc = crtc;
			crtc_state = to_intel_crtc_state(state->crtc_states[i]);
		}
	}
	for (i = 0; i < nconnectors; i++)
		if (state->connectors[i] != NULL)
			not_nuclear = true;

	if (not_nuclear) {
		DRM_DEBUG_KMS("i915 only supports atomic plane operations at the moment\n");
		return -EINVAL;
	}

	ret = drm_atomic_helper_check_planes(dev, state);
	if (ret)
		return ret;

	/* FIXME: move to crtc atomic check function once it is ready */
	ret = intel_atomic_setup_scalers(dev, nuclear_crtc, crtc_state);
	if (ret)
		return ret;

	return ret;
}


/**
 * intel_atomic_commit - commit validated state object
 * @dev: DRM device
 * @state: the top-level driver state object
 * @async: asynchronous commit
 *
 * This function commits a top-level state object that has been validated
 * with drm_atomic_helper_check().
 *
 * FIXME:  Atomic modeset support for i915 is not yet complete.  At the moment
 * we can only handle plane-related operations and do not yet support
 * asynchronous commit.
 *
 * RETURNS
 * Zero for success or -errno.
 */
int intel_atomic_commit(struct drm_device *dev,
			struct drm_atomic_state *state,
			bool async)
{
	struct drm_crtc_state *crtc_state;
	struct drm_crtc *crtc;
	int ret, i;

	if (async) {
		DRM_DEBUG_KMS("i915 does not yet support async commit\n");
		return -EINVAL;
	}

	ret = drm_atomic_helper_prepare_planes(dev, state);
	if (ret)
		return ret;

	/* Point of no return */
	drm_atomic_helper_swap_state(dev, state);

	/* swap crtc_scaler_state */
	for_each_crtc_in_state(state, crtc, crtc_state, i) {
		to_intel_crtc(crtc)->config = to_intel_crtc_state(crtc->state);

		if (INTEL_INFO(dev)->gen >= 9)
			skl_detach_scalers(to_intel_crtc(crtc));

		drm_atomic_helper_commit_planes_on_crtc(crtc_state);
	}

	drm_atomic_helper_wait_for_vblanks(dev, state);
	drm_atomic_helper_cleanup_planes(dev, state);
	drm_atomic_state_free(state);

	return 0;
}

/**
 * intel_connector_atomic_get_property - fetch connector property value
 * @connector: connector to fetch property for
 * @state: state containing the property value
 * @property: property to look up
 * @val: pointer to write property value into
 *
 * The DRM core does not store shadow copies of properties for
 * atomic-capable drivers.  This entrypoint is used to fetch
 * the current value of a driver-specific connector property.
 */
int
intel_connector_atomic_get_property(struct drm_connector *connector,
				    const struct drm_connector_state *state,
				    struct drm_property *property,
				    uint64_t *val)
{
	int i;

	/*
	 * TODO: We only have atomic modeset for planes at the moment, so the
	 * crtc/connector code isn't quite ready yet.  Until it's ready,
	 * continue to look up all property values in the DRM's shadow copy
	 * in obj->properties->values[].
	 *
	 * When the crtc/connector state work matures, this function should
	 * be updated to read the values out of the state structure instead.
	 */
	for (i = 0; i < connector->base.properties->count; i++) {
		if (connector->base.properties->properties[i] == property) {
			*val = connector->base.properties->values[i];
			return 0;
		}
	}

	return -EINVAL;
}

/*
 * intel_crtc_duplicate_state - duplicate crtc state
 * @crtc: drm crtc
 *
 * Allocates and returns a copy of the crtc state (both common and
 * Intel-specific) for the specified crtc.
 *
 * Returns: The newly allocated crtc state, or NULL on failure.
 */
struct drm_crtc_state *
intel_crtc_duplicate_state(struct drm_crtc *crtc)
{
	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
	struct intel_crtc_state *crtc_state;

	if (WARN_ON(!intel_crtc->config))
		crtc_state = kzalloc(sizeof(*crtc_state), GFP_KERNEL);
	else
		crtc_state = kmemdup(intel_crtc->config,
				     sizeof(*intel_crtc->config), GFP_KERNEL);

	if (!crtc_state)
		return NULL;

	__drm_atomic_helper_crtc_duplicate_state(crtc, &crtc_state->base);

	crtc_state->base.crtc = crtc;

	return &crtc_state->base;
}

/**
 * intel_crtc_destroy_state - destroy crtc state
 * @crtc: drm crtc
 *
 * Destroys the crtc state (both common and Intel-specific) for the
 * specified crtc.
 */
void
intel_crtc_destroy_state(struct drm_crtc *crtc,
			  struct drm_crtc_state *state)
{
	drm_atomic_helper_crtc_destroy_state(crtc, state);
}

/**
 * intel_atomic_setup_scalers() - setup scalers for crtc per staged requests
 * @dev: DRM device
 * @crtc: intel crtc
 * @crtc_state: incoming crtc_state to validate and setup scalers
 *
 * This function sets up scalers based on staged scaling requests for
 * a @crtc and its planes. It is called from crtc level check path. If request
 * is a supportable request, it attaches scalers to requested planes and crtc.
 *
 * This function takes into account the current scaler(s) in use by any planes
 * not being part of this atomic state
 *
 *  Returns:
 *         0 - scalers were setup succesfully
 *         error code - otherwise
 */
int intel_atomic_setup_scalers(struct drm_device *dev,
	struct intel_crtc *intel_crtc,
	struct intel_crtc_state *crtc_state)
{
	struct drm_plane *plane = NULL;
	struct intel_plane *intel_plane;
	struct intel_plane_state *plane_state = NULL;
	struct intel_crtc_scaler_state *scaler_state;
	struct drm_atomic_state *drm_state;
	int num_scalers_need;
	int i, j;

	if (INTEL_INFO(dev)->gen < 9 || !intel_crtc || !crtc_state)
		return 0;

	scaler_state = &crtc_state->scaler_state;
	drm_state = crtc_state->base.state;

	num_scalers_need = hweight32(scaler_state->scaler_users);
	DRM_DEBUG_KMS("crtc_state = %p need = %d avail = %d scaler_users = 0x%x\n",
		crtc_state, num_scalers_need, intel_crtc->num_scalers,
		scaler_state->scaler_users);

	/*
	 * High level flow:
	 * - staged scaler requests are already in scaler_state->scaler_users
	 * - check whether staged scaling requests can be supported
	 * - add planes using scalers that aren't in current transaction
	 * - assign scalers to requested users
	 * - as part of plane commit, scalers will be committed
	 *   (i.e., either attached or detached) to respective planes in hw
	 * - as part of crtc_commit, scaler will be either attached or detached
	 *   to crtc in hw
	 */

	/* fail if required scalers > available scalers */
	if (num_scalers_need > intel_crtc->num_scalers){
		DRM_DEBUG_KMS("Too many scaling requests %d > %d\n",
			num_scalers_need, intel_crtc->num_scalers);
		return -EINVAL;
	}

	/* walkthrough scaler_users bits and start assigning scalers */
	for (i = 0; i < sizeof(scaler_state->scaler_users) * 8; i++) {
		int *scaler_id;

		/* skip if scaler not required */
		if (!(scaler_state->scaler_users & (1 << i)))
			continue;

		if (i == SKL_CRTC_INDEX) {
			/* panel fitter case: assign as a crtc scaler */
			scaler_id = &scaler_state->scaler_id;
		} else {
			if (!drm_state)
				continue;

			/* plane scaler case: assign as a plane scaler */
			/* find the plane that set the bit as scaler_user */
			plane = drm_state->planes[i];

			/*
			 * to enable/disable hq mode, add planes that are using scaler
			 * into this transaction
			 */
			if (!plane) {
				struct drm_plane_state *state;
				plane = drm_plane_from_index(dev, i);
				state = drm_atomic_get_plane_state(drm_state, plane);
				if (IS_ERR(state)) {
					DRM_DEBUG_KMS("Failed to add [PLANE:%d] to drm_state\n",
						plane->base.id);
					return PTR_ERR(state);
				}
			}

			intel_plane = to_intel_plane(plane);

			/* plane on different crtc cannot be a scaler user of this crtc */
			if (WARN_ON(intel_plane->pipe != intel_crtc->pipe)) {
				continue;
			}

			plane_state = to_intel_plane_state(drm_state->plane_states[i]);
			scaler_id = &plane_state->scaler_id;
		}

		if (*scaler_id < 0) {
			/* find a free scaler */
			for (j = 0; j < intel_crtc->num_scalers; j++) {
				if (!scaler_state->scalers[j].in_use) {
					scaler_state->scalers[j].in_use = 1;
					*scaler_id = scaler_state->scalers[j].id;
					DRM_DEBUG_KMS("Attached scaler id %u.%u to %s:%d\n",
						intel_crtc->pipe,
						i == SKL_CRTC_INDEX ? scaler_state->scaler_id :
							plane_state->scaler_id,
						i == SKL_CRTC_INDEX ? "CRTC" : "PLANE",
						i == SKL_CRTC_INDEX ?  intel_crtc->base.base.id :
						plane->base.id);
					break;
				}
			}
		}

		if (WARN_ON(*scaler_id < 0)) {
			DRM_DEBUG_KMS("Cannot find scaler for %s:%d\n",
				i == SKL_CRTC_INDEX ? "CRTC" : "PLANE",
				i == SKL_CRTC_INDEX ? intel_crtc->base.base.id:plane->base.id);
			continue;
		}

		/* set scaler mode */
		if (num_scalers_need == 1 && intel_crtc->pipe != PIPE_C) {
			/*
			 * when only 1 scaler is in use on either pipe A or B,
			 * scaler 0 operates in high quality (HQ) mode.
			 * In this case use scaler 0 to take advantage of HQ mode
			 */
			*scaler_id = 0;
			scaler_state->scalers[0].in_use = 1;
			scaler_state->scalers[0].mode = PS_SCALER_MODE_HQ;
			scaler_state->scalers[1].in_use = 0;
		} else {
			scaler_state->scalers[*scaler_id].mode = PS_SCALER_MODE_DYN;
		}
	}

	return 0;
}
Commit	Line	Data
5ee67f1c MR	1	/*
	2	* Copyright © 2015 Intel Corporation
	3	*
	4	* Permission is hereby granted, free of charge, to any person obtaining a
	5	* copy of this software and associated documentation files (the "Software"),
	6	* to deal in the Software without restriction, including without limitation
	7	* the rights to use, copy, modify, merge, publish, distribute, sublicense,
	8	* and/or sell copies of the Software, and to permit persons to whom the
	9	* Software is furnished to do so, subject to the following conditions:
	10	*
	11	* The above copyright notice and this permission notice (including the next
	12	* paragraph) shall be included in all copies or substantial portions of the
	13	* Software.
	14	*
	15	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	16	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	17	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
	18	* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	19	* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
	20	* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
	21	* DEALINGS IN THE SOFTWARE.
	22	*/
	23
	24	/**
	25	* DOC: atomic modeset support
	26	*
	27	* The functions here implement the state management and hardware programming
	28	* dispatch required by the atomic modeset infrastructure.
	29	* See intel_atomic_plane.c for the plane-specific atomic functionality.
	30	*/
	31
	32	#include <drm/drmP.h>
	33	#include <drm/drm_atomic.h>
	34	#include <drm/drm_atomic_helper.h>
	35	#include <drm/drm_plane_helper.h>
	36	#include "intel_drv.h"
	37
	38
	39	/**
	40	* intel_atomic_check - validate state object
	41	* @dev: drm device
	42	* @state: state to validate
	43	*/
	44	int intel_atomic_check(struct drm_device *dev,
	45	struct drm_atomic_state *state)
	46	{
	47	int nplanes = dev->mode_config.num_total_plane;
	48	int ncrtcs = dev->mode_config.num_crtc;
	49	int nconnectors = dev->mode_config.num_connector;
	50	enum pipe nuclear_pipe = INVALID_PIPE;
e04fa803 CK	51	struct intel_crtc *nuclear_crtc = NULL;
e04fa803 CK	52	struct intel_crtc_state *crtc_state = NULL;
5ee67f1c MR	53	int ret;
	54	int i;
	55	bool not_nuclear = false;
	56
	57	/*
	58	* FIXME: At the moment, we only support "nuclear pageflip" on a
	59	* single CRTC. Cross-crtc updates will be added later.
	60	*/
	61	for (i = 0; i < nplanes; i++) {
	62	struct intel_plane *plane = to_intel_plane(state->planes[i]);
	63	if (!plane)
	64	continue;
	65
	66	if (nuclear_pipe == INVALID_PIPE) {
	67	nuclear_pipe = plane->pipe;
	68	} else if (nuclear_pipe != plane->pipe) {
	69	DRM_DEBUG_KMS("i915 only support atomic plane operations on a single CRTC at the moment\n");
	70	return -EINVAL;
	71	}
	72	}
	73
	74	/*
	75	* FIXME: We only handle planes for now; make sure there are no CRTC's
	76	* or connectors involved.
	77	*/
	78	state->allow_modeset = false;
	79	for (i = 0; i < ncrtcs; i++) {
	80	struct intel_crtc *crtc = to_intel_crtc(state->crtcs[i]);
f1e2daea MR	81	if (crtc)
f1e2daea MR	82	memset(&crtc->atomic, 0, sizeof(crtc->atomic));
5ee67f1c MR	83	if (crtc && crtc->pipe != nuclear_pipe)
5ee67f1c MR	84	not_nuclear = true;
e04fa803 CK	85	if (crtc && crtc->pipe == nuclear_pipe) {
	86	nuclear_crtc = crtc;
	87	crtc_state = to_intel_crtc_state(state->crtc_states[i]);
	88	}
5ee67f1c MR	89	}
	90	for (i = 0; i < nconnectors; i++)
	91	if (state->connectors[i] != NULL)
	92	not_nuclear = true;
	93
	94	if (not_nuclear) {
	95	DRM_DEBUG_KMS("i915 only supports atomic plane operations at the moment\n");
	96	return -EINVAL;
	97	}
	98
	99	ret = drm_atomic_helper_check_planes(dev, state);
	100	if (ret)
	101	return ret;
	102
e04fa803 CK	103	/* FIXME: move to crtc atomic check function once it is ready */
	104	ret = intel_atomic_setup_scalers(dev, nuclear_crtc, crtc_state);
	105	if (ret)
	106	return ret;
	107
5ee67f1c MR	108	return ret;
	109	}
	110
	111
	112	/**
	113	* intel_atomic_commit - commit validated state object
	114	* @dev: DRM device
	115	* @state: the top-level driver state object
	116	* @async: asynchronous commit
	117	*
	118	* This function commits a top-level state object that has been validated
	119	* with drm_atomic_helper_check().
	120	*
	121	* FIXME: Atomic modeset support for i915 is not yet complete. At the moment
	122	* we can only handle plane-related operations and do not yet support
	123	* asynchronous commit.
	124	*
	125	* RETURNS
	126	* Zero for success or -errno.
	127	*/
	128	int intel_atomic_commit(struct drm_device *dev,
	129	struct drm_atomic_state *state,
	130	bool async)
	131	{
d2944cf2 ML	132	struct drm_crtc_state *crtc_state;
	133	struct drm_crtc *crtc;
	134	int ret, i;
5ee67f1c MR	135
	136	if (async) {
	137	DRM_DEBUG_KMS("i915 does not yet support async commit\n");
	138	return -EINVAL;
	139	}
	140
	141	ret = drm_atomic_helper_prepare_planes(dev, state);
	142	if (ret)
	143	return ret;
	144
	145	/* Point of no return */
d2944cf2	146	drm_atomic_helper_swap_state(dev, state);
f76f35dc	147
6156a456	148	/* swap crtc_scaler_state */
d2944cf2 ML	149	for_each_crtc_in_state(state, crtc, crtc_state, i) {
d2944cf2 ML	150	to_intel_crtc(crtc)->config = to_intel_crtc_state(crtc->state);
6156a456 CK	151
	152	if (INTEL_INFO(dev)->gen >= 9)
	153	skl_detach_scalers(to_intel_crtc(crtc));
d2944cf2 ML	154
d2944cf2 ML	155	drm_atomic_helper_commit_planes_on_crtc(crtc_state);
f76f35dc CK	156	}
f76f35dc CK	157
5ee67f1c MR	158	drm_atomic_helper_wait_for_vblanks(dev, state);
	159	drm_atomic_helper_cleanup_planes(dev, state);
	160	drm_atomic_state_free(state);
	161
	162	return 0;
	163	}
2545e4a6 MR	164
	165	/**
	166	* intel_connector_atomic_get_property - fetch connector property value
	167	* @connector: connector to fetch property for
	168	* @state: state containing the property value
	169	* @property: property to look up
	170	* @val: pointer to write property value into
	171	*
	172	* The DRM core does not store shadow copies of properties for
	173	* atomic-capable drivers. This entrypoint is used to fetch
	174	* the current value of a driver-specific connector property.
	175	*/
	176	int
	177	intel_connector_atomic_get_property(struct drm_connector *connector,
	178	const struct drm_connector_state *state,
	179	struct drm_property *property,
	180	uint64_t *val)
	181	{
	182	int i;
	183
	184	/*
	185	* TODO: We only have atomic modeset for planes at the moment, so the
	186	* crtc/connector code isn't quite ready yet. Until it's ready,
	187	* continue to look up all property values in the DRM's shadow copy
	188	* in obj->properties->values[].
	189	*
	190	* When the crtc/connector state work matures, this function should
	191	* be updated to read the values out of the state structure instead.
	192	*/
	193	for (i = 0; i < connector->base.properties->count; i++) {
	194	if (connector->base.properties->properties[i] == property) {
	195	*val = connector->base.properties->values[i];
	196	return 0;
	197	}
	198	}
	199
	200	return -EINVAL;
	201	}
1356837e MR	202
	203	/*
	204	* intel_crtc_duplicate_state - duplicate crtc state
	205	* @crtc: drm crtc
	206	*
	207	* Allocates and returns a copy of the crtc state (both common and
	208	* Intel-specific) for the specified crtc.
	209	*
	210	* Returns: The newly allocated crtc state, or NULL on failure.
	211	*/
	212	struct drm_crtc_state *
	213	intel_crtc_duplicate_state(struct drm_crtc *crtc)
	214	{
	215	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
a91572f3	216	struct intel_crtc_state *crtc_state;
1356837e MR	217
1356837e MR	218	if (WARN_ON(!intel_crtc->config))
a91572f3 ACO	219	crtc_state = kzalloc(sizeof(*crtc_state), GFP_KERNEL);
	220	else
	221	crtc_state = kmemdup(intel_crtc->config,
	222	sizeof(*intel_crtc->config), GFP_KERNEL);
1356837e	223
f0c60574 ACO	224	if (!crtc_state)
	225	return NULL;
	226
	227	__drm_atomic_helper_crtc_duplicate_state(crtc, &crtc_state->base);
	228
	229	crtc_state->base.crtc = crtc;
a91572f3 ACO	230
a91572f3 ACO	231	return &crtc_state->base;
1356837e MR	232	}
	233
	234	/**
	235	* intel_crtc_destroy_state - destroy crtc state
	236	* @crtc: drm crtc
	237	*
	238	* Destroys the crtc state (both common and Intel-specific) for the
	239	* specified crtc.
	240	*/
	241	void
	242	intel_crtc_destroy_state(struct drm_crtc *crtc,
	243	struct drm_crtc_state *state)
	244	{
	245	drm_atomic_helper_crtc_destroy_state(crtc, state);
	246	}
d03c93d4 CK	247
	248	/**
	249	* intel_atomic_setup_scalers() - setup scalers for crtc per staged requests
	250	* @dev: DRM device
	251	* @crtc: intel crtc
	252	* @crtc_state: incoming crtc_state to validate and setup scalers
	253	*
	254	* This function sets up scalers based on staged scaling requests for
	255	* a @crtc and its planes. It is called from crtc level check path. If request
	256	* is a supportable request, it attaches scalers to requested planes and crtc.
	257	*
	258	* This function takes into account the current scaler(s) in use by any planes
	259	* not being part of this atomic state
	260	*
	261	* Returns:
	262	* 0 - scalers were setup succesfully
	263	* error code - otherwise
	264	*/
	265	int intel_atomic_setup_scalers(struct drm_device *dev,
	266	struct intel_crtc *intel_crtc,
	267	struct intel_crtc_state *crtc_state)
	268	{
	269	struct drm_plane *plane = NULL;
	270	struct intel_plane *intel_plane;
	271	struct intel_plane_state *plane_state = NULL;
	272	struct intel_crtc_scaler_state *scaler_state;
	273	struct drm_atomic_state *drm_state;
	274	int num_scalers_need;
	275	int i, j;
	276
	277	if (INTEL_INFO(dev)->gen < 9 \|\| !intel_crtc \|\| !crtc_state)
	278	return 0;
	279
	280	scaler_state = &crtc_state->scaler_state;
	281	drm_state = crtc_state->base.state;
	282
	283	num_scalers_need = hweight32(scaler_state->scaler_users);
	284	DRM_DEBUG_KMS("crtc_state = %p need = %d avail = %d scaler_users = 0x%x\n",
	285	crtc_state, num_scalers_need, intel_crtc->num_scalers,
	286	scaler_state->scaler_users);
	287
	288	/*
	289	* High level flow:
	290	* - staged scaler requests are already in scaler_state->scaler_users
	291	* - check whether staged scaling requests can be supported
	292	* - add planes using scalers that aren't in current transaction
	293	* - assign scalers to requested users
	294	* - as part of plane commit, scalers will be committed
	295	* (i.e., either attached or detached) to respective planes in hw
	296	* - as part of crtc_commit, scaler will be either attached or detached
	297	* to crtc in hw
	298	*/
	299
	300	/* fail if required scalers > available scalers */
	301	if (num_scalers_need > intel_crtc->num_scalers){
	302	DRM_DEBUG_KMS("Too many scaling requests %d > %d\n",
	303	num_scalers_need, intel_crtc->num_scalers);
	304	return -EINVAL;
	305	}
	306
	307	/* walkthrough scaler_users bits and start assigning scalers */
	308	for (i = 0; i < sizeof(scaler_state->scaler_users) * 8; i++) {
	309	int *scaler_id;
	310
311	/* skip if scaler not required */
312	if (!(scaler_state->scaler_users & (1 << i)))
313	continue;
314
315	if (i == SKL_CRTC_INDEX) {
316	/* panel fitter case: assign as a crtc scaler */
317	scaler_id = &scaler_state->scaler_id;
318	} else {
319	if (!drm_state)
320	continue;
321
322	/* plane scaler case: assign as a plane scaler */
323	/* find the plane that set the bit as scaler_user */
324	plane = drm_state->planes[i];
325
326	/*
327	* to enable/disable hq mode, add planes that are using scaler
328	* into this transaction
329	*/
330	if (!plane) {
331	struct drm_plane_state *state;
332	plane = drm_plane_from_index(dev, i);
333	state = drm_atomic_get_plane_state(drm_state, plane);
334	if (IS_ERR(state)) {
335	DRM_DEBUG_KMS("Failed to add [PLANE:%d] to drm_state\n",
336	plane->base.id);
337	return PTR_ERR(state);
338	}
339	}
340
341	intel_plane = to_intel_plane(plane);
342
343	/* plane on different crtc cannot be a scaler user of this crtc */
344	if (WARN_ON(intel_plane->pipe != intel_crtc->pipe)) {
345	continue;
346	}
347
348	plane_state = to_intel_plane_state(drm_state->plane_states[i]);
349	scaler_id = &plane_state->scaler_id;
350	}
351
352	if (*scaler_id < 0) {
353	/* find a free scaler */
354	for (j = 0; j < intel_crtc->num_scalers; j++) {
355	if (!scaler_state->scalers[j].in_use) {
356	scaler_state->scalers[j].in_use = 1;
357	*scaler_id = scaler_state->scalers[j].id;
358	DRM_DEBUG_KMS("Attached scaler id %u.%u to %s:%d\n",
359	intel_crtc->pipe,
360	i == SKL_CRTC_INDEX ? scaler_state->scaler_id :
361	plane_state->scaler_id,
362	i == SKL_CRTC_INDEX ? "CRTC" : "PLANE",
363	i == SKL_CRTC_INDEX ? intel_crtc->base.base.id :
364	plane->base.id);
365	break;
366	}
367	}
368	}
369
370	if (WARN_ON(*scaler_id < 0)) {
371	DRM_DEBUG_KMS("Cannot find scaler for %s:%d\n",
372	i == SKL_CRTC_INDEX ? "CRTC" : "PLANE",
373	i == SKL_CRTC_INDEX ? intel_crtc->base.base.id:plane->base.id);
374	continue;
375	}
376
377	/* set scaler mode */
378	if (num_scalers_need == 1 && intel_crtc->pipe != PIPE_C) {
379	/*
380	* when only 1 scaler is in use on either pipe A or B,
381	* scaler 0 operates in high quality (HQ) mode.
382	* In this case use scaler 0 to take advantage of HQ mode
383	*/
384	*scaler_id = 0;
385	scaler_state->scalers[0].in_use = 1;
386	scaler_state->scalers[0].mode = PS_SCALER_MODE_HQ;
387	scaler_state->scalers[1].in_use = 0;
388	} else {
389	scaler_state->scalers[*scaler_id].mode = PS_SCALER_MODE_DYN;
390	}
391	}
392
393	return 0;
394	}