i915.c - chromiumos/platform/minigbm - Git at Google

 /*
  * Copyright 2014 The Chromium OS Authors. All rights reserved.
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */

 #ifdef DRV_I915

 #include <errno.h>
 #include <i915_drm.h>
 #include <intel_bufmgr.h>
 #include <string.h>
 #include <sys/mman.h>
 #include <xf86drm.h>

 #include "drv_priv.h"
 #include "helpers.h"
 #include "util.h"

 static const uint32_t tileable_formats[] = { DRM_FORMAT_ARGB1555, DRM_FORMAT_ABGR8888,
 					     DRM_FORMAT_ARGB8888, DRM_FORMAT_RGB565,
 					     DRM_FORMAT_XBGR8888, DRM_FORMAT_XRGB1555,
 					     DRM_FORMAT_XRGB8888, DRM_FORMAT_UYVY,
 					     DRM_FORMAT_YUYV };

 static const uint32_t linear_only_formats[] = { DRM_FORMAT_GR88, DRM_FORMAT_R8, DRM_FORMAT_YVU420,
 						DRM_FORMAT_YVU420_ANDROID };

 struct i915_device {
 	int gen;
 	drm_intel_bufmgr *mgr;
 	uint32_t count;
 };

 struct i915_bo {
 	drm_intel_bo *ibos[DRV_MAX_PLANES];
 };

 static int get_gen(int device_id)
 {
 	const uint16_t gen3_ids[] = { 0x2582, 0x2592, 0x2772, 0x27A2, 0x27AE,
 				      0x29C2, 0x29B2, 0x29D2, 0xA001, 0xA011 };
 	unsigned i;
 	for (i = 0; i < ARRAY_SIZE(gen3_ids); i++)
 		if (gen3_ids[i] == device_id)
 			return 3;

 	return 4;
 }

 static int i915_add_kms_item(struct driver *drv, const struct kms_item *item)
 {
 	uint32_t i;
 	struct combination *combo;

 	/*
 	 * Older hardware can't scanout Y-tiled formats. Newer devices can, and
 	 * report this functionality via format modifiers.
 	 */
 	for (i = 0; i < drv->backend->combos.size; i++) {
 		combo = &drv->backend->combos.data[i];
 		if (combo->format == item->format) {
 			if ((combo->metadata.tiling == I915_TILING_Y &&
 			     item->modifier == I915_FORMAT_MOD_Y_TILED) ||
 			    (combo->metadata.tiling == I915_TILING_X &&
 			     item->modifier == I915_FORMAT_MOD_X_TILED)) {
 				combo->metadata.modifier = item->modifier;
 				combo->usage |= item->usage;
 			} else if (combo->metadata.tiling != I915_TILING_Y) {
 				combo->usage |= item->usage;
 			}
 		}
 	}

 	return 0;
 }

 static int i915_add_combinations(struct driver *drv)
 {
 	int ret;
 	uint32_t i, num_items;
 	struct kms_item *items;
 	struct format_metadata metadata;
 	uint64_t flags = BO_COMMON_USE_MASK;

 	metadata.tiling = I915_TILING_NONE;
 	metadata.priority = 1;
 	metadata.modifier = DRM_FORMAT_MOD_NONE;

 	ret = drv_add_combinations(drv, linear_only_formats, ARRAY_SIZE(linear_only_formats),
 				   &metadata, flags);
 	if (ret)
 		return ret;

 	ret = drv_add_combinations(drv, tileable_formats, ARRAY_SIZE(tileable_formats), &metadata,
 				   flags);
 	if (ret)
 		return ret;

 	drv_modify_combination(drv, DRM_FORMAT_XRGB8888, &metadata, BO_USE_CURSOR | BO_USE_SCANOUT);
 	drv_modify_combination(drv, DRM_FORMAT_ARGB8888, &metadata, BO_USE_CURSOR | BO_USE_SCANOUT);

 	flags &= ~BO_USE_SW_WRITE_OFTEN;
 	flags &= ~BO_USE_SW_READ_OFTEN;
 	flags &= ~BO_USE_LINEAR;

 	metadata.tiling = I915_TILING_X;
 	metadata.priority = 2;

 	ret = drv_add_combinations(drv, tileable_formats, ARRAY_SIZE(tileable_formats), &metadata,
 				   flags);
 	if (ret)
 		return ret;

 	metadata.tiling = I915_TILING_Y;
 	metadata.priority = 3;

 	ret = drv_add_combinations(drv, tileable_formats, ARRAY_SIZE(tileable_formats), &metadata,
 				   flags);
 	if (ret)
 		return ret;

 	items = drv_query_kms(drv, &num_items);
 	if (!items || !num_items)
 		return 0;

 	for (i = 0; i < num_items; i++) {
 		ret = i915_add_kms_item(drv, &items[i]);
 		if (ret) {
 			free(items);
 			return ret;
 		}
 	}

 	free(items);
 	return 0;
 }

 static int i915_align_dimensions(struct bo *bo, uint32_t tiling, uint32_t *stride,
 				 uint32_t *aligned_height)
 {
 	struct i915_device *i915 = bo->drv->priv;
 	uint32_t horizontal_alignment = 4;
 	uint32_t vertical_alignment = 4;

 	switch (tiling) {
 	default:
 	case I915_TILING_NONE:
 		horizontal_alignment = 64;
 		break;

 	case I915_TILING_X:
 		horizontal_alignment = 512;
 		vertical_alignment = 8;
 		break;

 	case I915_TILING_Y:
 		if (i915->gen == 3) {
 			horizontal_alignment = 512;
 			vertical_alignment = 8;
 		} else {
 			horizontal_alignment = 128;
 			vertical_alignment = 32;
 		}
 		break;
 	}

 	*aligned_height = ALIGN(bo->height, vertical_alignment);
 	if (i915->gen > 3) {
 		*stride = ALIGN(*stride, horizontal_alignment);
 	} else {
 		while (*stride > horizontal_alignment)
 			horizontal_alignment <<= 1;

 		*stride = horizontal_alignment;
 	}

 	if (i915->gen <= 3 && *stride > 8192)
 		return -EINVAL;

 	return 0;
 }

 static int i915_init(struct driver *drv)
 {
 	struct i915_device *i915_dev;
 	drm_i915_getparam_t get_param;
 	int device_id;
 	int ret;

 	i915_dev = calloc(1, sizeof(*i915_dev));
 	if (!i915_dev)
 		return -1;

 	memset(&get_param, 0, sizeof(get_param));
 	get_param.param = I915_PARAM_CHIPSET_ID;
 	get_param.value = &device_id;
 	ret = drmIoctl(drv->fd, DRM_IOCTL_I915_GETPARAM, &get_param);
 	if (ret) {
 		fprintf(stderr, "drv: DRM_IOCTL_I915_GETPARAM failed\n");
 		free(i915_dev);
 		return -EINVAL;
 	}

 	i915_dev->gen = get_gen(device_id);
 	i915_dev->count = 0;

 	i915_dev->mgr = drm_intel_bufmgr_gem_init(drv->fd, 16 * 1024);
 	if (!i915_dev->mgr) {
 		fprintf(stderr, "drv: drm_intel_bufmgr_gem_init failed\n");
 		free(i915_dev);
 		return -EINVAL;
 	}

 	drv->priv = i915_dev;

 	return i915_add_combinations(drv);
 }

 static void i915_close(struct driver *drv)
 {
 	struct i915_device *i915_dev = drv->priv;
 	drm_intel_bufmgr_destroy(i915_dev->mgr);
 	free(i915_dev);
 	drv->priv = NULL;
 }

 static int i915_bo_create(struct bo *bo, uint32_t width, uint32_t height, uint32_t format,
 			  uint32_t flags)
 {
 	int ret;
 	size_t plane;
 	char name[20];
 	uint32_t stride;
 	uint32_t tiling_mode;
 	struct i915_bo *i915_bo;

 	stride = drv_stride_from_format(format, width, 0);
 	struct i915_device *i915_dev = (struct i915_device *)bo->drv->priv;

 	if (flags & (BO_USE_CURSOR | BO_USE_LINEAR | BO_USE_SW_READ_OFTEN | BO_USE_SW_WRITE_OFTEN))
 		tiling_mode = I915_TILING_NONE;
 	else if (flags & BO_USE_SCANOUT)
 		tiling_mode = I915_TILING_X;
 	else
 		tiling_mode = I915_TILING_Y;

 	/*
 	 * Align the Y plane to 128 bytes so the chroma planes would be aligned
 	 * to 64 byte boundaries. This is an Intel HW requirement.
 	 */
 	if (format == DRM_FORMAT_YVU420 || format == DRM_FORMAT_YVU420_ANDROID) {
 		stride = ALIGN(stride, 128);
 		tiling_mode = I915_TILING_NONE;
 	}

 	ret = i915_align_dimensions(bo, tiling_mode, &stride, &height);
 	if (ret)
 		return ret;

 	drv_bo_from_format(bo, stride, height, format);

 	snprintf(name, sizeof(name), "i915-buffer-%u", i915_dev->count);
 	i915_dev->count++;

 	i915_bo = calloc(1, sizeof(*i915_bo));
 	if (!i915_bo)
 		return -ENOMEM;

 	bo->priv = i915_bo;

 	i915_bo->ibos[0] = drm_intel_bo_alloc(i915_dev->mgr, name, bo->total_size, 0);
 	if (!i915_bo->ibos[0]) {
 		fprintf(stderr, "drv: drm_intel_bo_alloc failed");
 		free(i915_bo);
 		bo->priv = NULL;
 		return -ENOMEM;
 	}

 	for (plane = 0; plane < bo->num_planes; plane++) {
 		if (plane > 0)
 			drm_intel_bo_reference(i915_bo->ibos[0]);

 		bo->handles[plane].u32 = i915_bo->ibos[0]->handle;
 		i915_bo->ibos[plane] = i915_bo->ibos[0];
 	}

 	bo->tiling = tiling_mode;

 	ret = drm_intel_bo_set_tiling(i915_bo->ibos[0], &bo->tiling, bo->strides[0]);

 	if (ret || bo->tiling != tiling_mode) {
 		fprintf(stderr, "drv: drm_intel_gem_bo_set_tiling failed errno=%x, stride=%x\n",
 			errno, bo->strides[0]);
 		/* Calls i915 bo destroy. */
 		bo->drv->backend->bo_destroy(bo);
 		return -errno;
 	}

 	return 0;
 }

 static int i915_bo_destroy(struct bo *bo)
 {
 	size_t plane;
 	struct i915_bo *i915_bo = bo->priv;

 	for (plane = 0; plane < bo->num_planes; plane++)
 		drm_intel_bo_unreference(i915_bo->ibos[plane]);

 	free(i915_bo);
 	bo->priv = NULL;

 	return 0;
 }

 static int i915_bo_import(struct bo *bo, struct drv_import_fd_data *data)
 {
 	size_t plane;
 	uint32_t swizzling;
 	struct i915_bo *i915_bo;
 	struct i915_device *i915_dev = bo->drv->priv;

 	i915_bo = calloc(1, sizeof(*i915_bo));
 	if (!i915_bo)
 		return -ENOMEM;

 	bo->priv = i915_bo;

 	/*
 	 * When self-importing, libdrm_intel increments the reference count
 	 * on the drm_intel_bo. It also returns the same drm_intel_bo per GEM
 	 * handle. Thus, we don't need to increase the reference count
 	 * (i.e, drv_increment_reference_count) when importing with this
 	 * backend.
 	 */
 	for (plane = 0; plane < bo->num_planes; plane++) {

 		i915_bo->ibos[plane] = drm_intel_bo_gem_create_from_prime(
 		    i915_dev->mgr, data->fds[plane], data->sizes[plane]);

 		if (!i915_bo->ibos[plane]) {
 			/*
 			 * Need to call GEM close on planes that were opened,
 			 * if any. Adjust the num_planes variable to be the
 			 * plane that failed, so GEM close will be called on
 			 * planes before that plane.
 			 */
 			bo->num_planes = plane;
 			i915_bo_destroy(bo);
 			fprintf(stderr, "drv: i915: failed to import failed");
 			return -EINVAL;
 		}

 		bo->handles[plane].u32 = i915_bo->ibos[plane]->handle;
 	}

 	if (drm_intel_bo_get_tiling(i915_bo->ibos[0], &bo->tiling, &swizzling)) {
 		fprintf(stderr, "drv: drm_intel_bo_get_tiling failed");
 		i915_bo_destroy(bo);
 		return -EINVAL;
 	}

 	return 0;
 }

 static void *i915_bo_map(struct bo *bo, struct map_info *data, size_t plane)
 {
 	int ret;
 	struct i915_bo *i915_bo = bo->priv;

 	if (bo->tiling == I915_TILING_NONE)
 		/* TODO(gsingh): use bo_map flags to determine if we should
 		 * enable writing.
 		 */
 		ret = drm_intel_bo_map(i915_bo->ibos[0], 1);
 	else
 		ret = drm_intel_gem_bo_map_gtt(i915_bo->ibos[0]);

 	if (ret) {
 		fprintf(stderr, "drv: i915_bo_map failed.");
 		return MAP_FAILED;
 	}

 	return i915_bo->ibos[0]->virtual;
 }

 static int i915_bo_unmap(struct bo *bo, struct map_info *data)
 {
 	int ret;
 	struct i915_bo *i915_bo = bo->priv;

 	if (bo->tiling == I915_TILING_NONE)
 		ret = drm_intel_bo_unmap(i915_bo->ibos[0]);
 	else
 		ret = drm_intel_gem_bo_unmap_gtt(i915_bo->ibos[0]);

 	return ret;
 }

 static uint32_t i915_resolve_format(uint32_t format)
 {
 	switch (format) {
 	case DRM_FORMAT_FLEX_IMPLEMENTATION_DEFINED:
 		/*HACK: See b/28671744 */
 		return DRM_FORMAT_XBGR8888;
 	case DRM_FORMAT_FLEX_YCbCr_420_888:
 		return DRM_FORMAT_YVU420_ANDROID;
 	default:
 		return format;
 	}
 }

 struct backend backend_i915 = {
 	.name = "i915",
 	.init = i915_init,
 	.close = i915_close,
 	.bo_create = i915_bo_create,
 	.bo_destroy = i915_bo_destroy,
 	.bo_import = i915_bo_import,
 	.bo_map = i915_bo_map,
 	.bo_unmap = i915_bo_unmap,
 	.resolve_format = i915_resolve_format,
 };

 #endif
	/*
	* Copyright 2014 The Chromium OS Authors. All rights reserved.
	* Use of this source code is governed by a BSD-style license that can be
	* found in the LICENSE file.
	*/

	#ifdef DRV_I915

	#include <errno.h>
	#include <i915_drm.h>
	#include <intel_bufmgr.h>
	#include <string.h>
	#include <sys/mman.h>
	#include <xf86drm.h>

	#include "drv_priv.h"
	#include "helpers.h"
	#include "util.h"

	static const uint32_t tileable_formats[] = { DRM_FORMAT_ARGB1555, DRM_FORMAT_ABGR8888,
	DRM_FORMAT_ARGB8888, DRM_FORMAT_RGB565,
	DRM_FORMAT_XBGR8888, DRM_FORMAT_XRGB1555,
	DRM_FORMAT_XRGB8888, DRM_FORMAT_UYVY,
	DRM_FORMAT_YUYV };

	static const uint32_t linear_only_formats[] = { DRM_FORMAT_GR88, DRM_FORMAT_R8, DRM_FORMAT_YVU420,
	DRM_FORMAT_YVU420_ANDROID };

	struct i915_device {
	int gen;
	drm_intel_bufmgr *mgr;
	uint32_t count;
	};

	struct i915_bo {
	drm_intel_bo *ibos[DRV_MAX_PLANES];
	};

	static int get_gen(int device_id)
	{
	const uint16_t gen3_ids[] = { 0x2582, 0x2592, 0x2772, 0x27A2, 0x27AE,
	0x29C2, 0x29B2, 0x29D2, 0xA001, 0xA011 };
	unsigned i;
	for (i = 0; i < ARRAY_SIZE(gen3_ids); i++)
	if (gen3_ids[i] == device_id)
	return 3;

	return 4;
	}

	static int i915_add_kms_item(struct driver drv, const struct kms_item item)
	{
	uint32_t i;
	struct combination *combo;

	/*
	* Older hardware can't scanout Y-tiled formats. Newer devices can, and
	* report this functionality via format modifiers.
	*/
	for (i = 0; i < drv->backend->combos.size; i++) {
	combo = &drv->backend->combos.data[i];
	if (combo->format == item->format) {
	if ((combo->metadata.tiling == I915_TILING_Y &&
	item->modifier == I915_FORMAT_MOD_Y_TILED) \|\|
	(combo->metadata.tiling == I915_TILING_X &&
	item->modifier == I915_FORMAT_MOD_X_TILED)) {
	combo->metadata.modifier = item->modifier;
	combo->usage \|= item->usage;
	} else if (combo->metadata.tiling != I915_TILING_Y) {
	combo->usage \|= item->usage;
	}
	}
	}

	return 0;
	}

	static int i915_add_combinations(struct driver *drv)
	{
	int ret;
	uint32_t i, num_items;
	struct kms_item *items;
	struct format_metadata metadata;
	uint64_t flags = BO_COMMON_USE_MASK;

	metadata.tiling = I915_TILING_NONE;
	metadata.priority = 1;
	metadata.modifier = DRM_FORMAT_MOD_NONE;

	ret = drv_add_combinations(drv, linear_only_formats, ARRAY_SIZE(linear_only_formats),
	&metadata, flags);
	if (ret)
	return ret;

	ret = drv_add_combinations(drv, tileable_formats, ARRAY_SIZE(tileable_formats), &metadata,
	flags);
	if (ret)
	return ret;

	drv_modify_combination(drv, DRM_FORMAT_XRGB8888, &metadata, BO_USE_CURSOR \| BO_USE_SCANOUT);
	drv_modify_combination(drv, DRM_FORMAT_ARGB8888, &metadata, BO_USE_CURSOR \| BO_USE_SCANOUT);

	flags &= ~BO_USE_SW_WRITE_OFTEN;
	flags &= ~BO_USE_SW_READ_OFTEN;
	flags &= ~BO_USE_LINEAR;

	metadata.tiling = I915_TILING_X;
	metadata.priority = 2;

	ret = drv_add_combinations(drv, tileable_formats, ARRAY_SIZE(tileable_formats), &metadata,
	flags);
	if (ret)
	return ret;

	metadata.tiling = I915_TILING_Y;
	metadata.priority = 3;

	ret = drv_add_combinations(drv, tileable_formats, ARRAY_SIZE(tileable_formats), &metadata,
	flags);
	if (ret)
	return ret;

	items = drv_query_kms(drv, &num_items);
	if (!items \|\| !num_items)
	return 0;

	for (i = 0; i < num_items; i++) {
	ret = i915_add_kms_item(drv, &items[i]);
	if (ret) {
	free(items);
	return ret;
	}
	}

	free(items);
	return 0;
	}

	static int i915_align_dimensions(struct bo bo, uint32_t tiling, uint32_t stride,
	uint32_t *aligned_height)
	{
	struct i915_device *i915 = bo->drv->priv;
	uint32_t horizontal_alignment = 4;
	uint32_t vertical_alignment = 4;

	switch (tiling) {
	default:
	case I915_TILING_NONE:
	horizontal_alignment = 64;
	break;

	case I915_TILING_X:
	horizontal_alignment = 512;
	vertical_alignment = 8;
	break;

	case I915_TILING_Y:
	if (i915->gen == 3) {
	horizontal_alignment = 512;
	vertical_alignment = 8;
	} else {
	horizontal_alignment = 128;
	vertical_alignment = 32;
	}
	break;
	}

	*aligned_height = ALIGN(bo->height, vertical_alignment);
	if (i915->gen > 3) {
	stride = ALIGN(stride, horizontal_alignment);
	} else {
	while (*stride > horizontal_alignment)
	horizontal_alignment <<= 1;

	*stride = horizontal_alignment;
	}

	if (i915->gen <= 3 && *stride > 8192)
	return -EINVAL;

	return 0;
	}

	static int i915_init(struct driver *drv)
	{
	struct i915_device *i915_dev;
	drm_i915_getparam_t get_param;
	int device_id;
	int ret;

	i915_dev = calloc(1, sizeof(*i915_dev));
	if (!i915_dev)
	return -1;

	memset(&get_param, 0, sizeof(get_param));
	get_param.param = I915_PARAM_CHIPSET_ID;
	get_param.value = &device_id;
	ret = drmIoctl(drv->fd, DRM_IOCTL_I915_GETPARAM, &get_param);
	if (ret) {
	fprintf(stderr, "drv: DRM_IOCTL_I915_GETPARAM failed\n");
	free(i915_dev);
	return -EINVAL;
	}

	i915_dev->gen = get_gen(device_id);
	i915_dev->count = 0;

	i915_dev->mgr = drm_intel_bufmgr_gem_init(drv->fd, 16 * 1024);
	if (!i915_dev->mgr) {
	fprintf(stderr, "drv: drm_intel_bufmgr_gem_init failed\n");
	free(i915_dev);
	return -EINVAL;
	}

	drv->priv = i915_dev;

	return i915_add_combinations(drv);
	}

	static void i915_close(struct driver *drv)
	{
	struct i915_device *i915_dev = drv->priv;
	drm_intel_bufmgr_destroy(i915_dev->mgr);
	free(i915_dev);
	drv->priv = NULL;
	}

	static int i915_bo_create(struct bo *bo, uint32_t width, uint32_t height, uint32_t format,
	uint32_t flags)
	{
	int ret;
	size_t plane;
	char name[20];
	uint32_t stride;
	uint32_t tiling_mode;
	struct i915_bo *i915_bo;

	stride = drv_stride_from_format(format, width, 0);
	struct i915_device i915_dev = (struct i915_device )bo->drv->priv;

	if (flags & (BO_USE_CURSOR \| BO_USE_LINEAR \| BO_USE_SW_READ_OFTEN \| BO_USE_SW_WRITE_OFTEN))
	tiling_mode = I915_TILING_NONE;
	else if (flags & BO_USE_SCANOUT)
	tiling_mode = I915_TILING_X;
	else
	tiling_mode = I915_TILING_Y;

	/*
	* Align the Y plane to 128 bytes so the chroma planes would be aligned
	* to 64 byte boundaries. This is an Intel HW requirement.
	*/
	if (format == DRM_FORMAT_YVU420 \|\| format == DRM_FORMAT_YVU420_ANDROID) {
	stride = ALIGN(stride, 128);
	tiling_mode = I915_TILING_NONE;
	}

	ret = i915_align_dimensions(bo, tiling_mode, &stride, &height);
	if (ret)
	return ret;

	drv_bo_from_format(bo, stride, height, format);

	snprintf(name, sizeof(name), "i915-buffer-%u", i915_dev->count);
	i915_dev->count++;

	i915_bo = calloc(1, sizeof(*i915_bo));
	if (!i915_bo)
	return -ENOMEM;

	bo->priv = i915_bo;

	i915_bo->ibos[0] = drm_intel_bo_alloc(i915_dev->mgr, name, bo->total_size, 0);
	if (!i915_bo->ibos[0]) {
	fprintf(stderr, "drv: drm_intel_bo_alloc failed");
	free(i915_bo);
	bo->priv = NULL;
	return -ENOMEM;
	}

	for (plane = 0; plane < bo->num_planes; plane++) {
	if (plane > 0)
	drm_intel_bo_reference(i915_bo->ibos[0]);

	bo->handles[plane].u32 = i915_bo->ibos[0]->handle;
	i915_bo->ibos[plane] = i915_bo->ibos[0];
	}

	bo->tiling = tiling_mode;

	ret = drm_intel_bo_set_tiling(i915_bo->ibos[0], &bo->tiling, bo->strides[0]);

	if (ret \|\| bo->tiling != tiling_mode) {
	fprintf(stderr, "drv: drm_intel_gem_bo_set_tiling failed errno=%x, stride=%x\n",
	errno, bo->strides[0]);
	/* Calls i915 bo destroy. */
	bo->drv->backend->bo_destroy(bo);
	return -errno;
	}

	return 0;
	}

	static int i915_bo_destroy(struct bo *bo)
	{
	size_t plane;
	struct i915_bo *i915_bo = bo->priv;

	for (plane = 0; plane < bo->num_planes; plane++)
	drm_intel_bo_unreference(i915_bo->ibos[plane]);

	free(i915_bo);
	bo->priv = NULL;

	return 0;
	}

	static int i915_bo_import(struct bo bo, struct drv_import_fd_data data)
	{
	size_t plane;
	uint32_t swizzling;
	struct i915_bo *i915_bo;
	struct i915_device *i915_dev = bo->drv->priv;

	i915_bo = calloc(1, sizeof(*i915_bo));
	if (!i915_bo)
	return -ENOMEM;

	bo->priv = i915_bo;

	/*
	* When self-importing, libdrm_intel increments the reference count
	* on the drm_intel_bo. It also returns the same drm_intel_bo per GEM
	* handle. Thus, we don't need to increase the reference count
	* (i.e, drv_increment_reference_count) when importing with this
	* backend.
	*/
	for (plane = 0; plane < bo->num_planes; plane++) {

	i915_bo->ibos[plane] = drm_intel_bo_gem_create_from_prime(
	i915_dev->mgr, data->fds[plane], data->sizes[plane]);

	if (!i915_bo->ibos[plane]) {
	/*
	* Need to call GEM close on planes that were opened,
	* if any. Adjust the num_planes variable to be the
	* plane that failed, so GEM close will be called on
	* planes before that plane.
	*/
	bo->num_planes = plane;
	i915_bo_destroy(bo);
	fprintf(stderr, "drv: i915: failed to import failed");
	return -EINVAL;
	}

	bo->handles[plane].u32 = i915_bo->ibos[plane]->handle;
	}

	if (drm_intel_bo_get_tiling(i915_bo->ibos[0], &bo->tiling, &swizzling)) {
	fprintf(stderr, "drv: drm_intel_bo_get_tiling failed");
	i915_bo_destroy(bo);
	return -EINVAL;
	}

	return 0;
	}

	static void i915_bo_map(struct bo bo, struct map_info *data, size_t plane)
	{
	int ret;
	struct i915_bo *i915_bo = bo->priv;

	if (bo->tiling == I915_TILING_NONE)
	/* TODO(gsingh): use bo_map flags to determine if we should
	* enable writing.
	*/
	ret = drm_intel_bo_map(i915_bo->ibos[0], 1);
	else
	ret = drm_intel_gem_bo_map_gtt(i915_bo->ibos[0]);

	if (ret) {
	fprintf(stderr, "drv: i915_bo_map failed.");
	return MAP_FAILED;
	}

	return i915_bo->ibos[0]->virtual;
	}

	static int i915_bo_unmap(struct bo bo, struct map_info data)
	{
	int ret;
	struct i915_bo *i915_bo = bo->priv;

	if (bo->tiling == I915_TILING_NONE)
	ret = drm_intel_bo_unmap(i915_bo->ibos[0]);
	else
	ret = drm_intel_gem_bo_unmap_gtt(i915_bo->ibos[0]);

	return ret;
	}

	static uint32_t i915_resolve_format(uint32_t format)
	{
	switch (format) {
	case DRM_FORMAT_FLEX_IMPLEMENTATION_DEFINED:
	/HACK: See b/28671744 /
	return DRM_FORMAT_XBGR8888;
	case DRM_FORMAT_FLEX_YCbCr_420_888:
	return DRM_FORMAT_YVU420_ANDROID;
	default:
	return format;
	}
	}

	struct backend backend_i915 = {
	.name = "i915",
	.init = i915_init,
	.close = i915_close,
	.bo_create = i915_bo_create,
	.bo_destroy = i915_bo_destroy,
	.bo_import = i915_bo_import,
	.bo_map = i915_bo_map,
	.bo_unmap = i915_bo_unmap,
	.resolve_format = i915_resolve_format,
	};

	#endif