helpers.c - platform/external/minigbm - Gitiles

 /*
  * 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.
  */

 #include <assert.h>
 #include <errno.h>
 #include <stdbool.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <sys/mman.h>
 #include <xf86drm.h>
 #include <xf86drmMode.h>

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

 static uint32_t subsample_stride(uint32_t stride, uint32_t format, size_t plane)
 {

 	if (plane != 0) {
 		switch (format) {
 		case DRM_FORMAT_YVU420:
 		case DRM_FORMAT_YVU420_ANDROID:
 			stride = DIV_ROUND_UP(stride, 2);
 			break;
 		}
 	}

 	return stride;
 }

 static uint32_t bpp_from_format(uint32_t format, size_t plane)
 {
 	assert(plane < drv_num_planes_from_format(format));

 	switch (format) {
 	case DRM_FORMAT_BGR233:
 	case DRM_FORMAT_C8:
 	case DRM_FORMAT_R8:
 	case DRM_FORMAT_RGB332:
 	case DRM_FORMAT_YVU420:
 	case DRM_FORMAT_YVU420_ANDROID:
 		return 8;

 	case DRM_FORMAT_NV12:
 	case DRM_FORMAT_NV21:
 		return (plane == 0) ? 8 : 4;

 	case DRM_FORMAT_ABGR1555:
 	case DRM_FORMAT_ABGR4444:
 	case DRM_FORMAT_ARGB1555:
 	case DRM_FORMAT_ARGB4444:
 	case DRM_FORMAT_BGR565:
 	case DRM_FORMAT_BGRA4444:
 	case DRM_FORMAT_BGRA5551:
 	case DRM_FORMAT_BGRX4444:
 	case DRM_FORMAT_BGRX5551:
 	case DRM_FORMAT_GR88:
 	case DRM_FORMAT_RG88:
 	case DRM_FORMAT_RGB565:
 	case DRM_FORMAT_RGBA4444:
 	case DRM_FORMAT_RGBA5551:
 	case DRM_FORMAT_RGBX4444:
 	case DRM_FORMAT_RGBX5551:
 	case DRM_FORMAT_UYVY:
 	case DRM_FORMAT_VYUY:
 	case DRM_FORMAT_XBGR1555:
 	case DRM_FORMAT_XBGR4444:
 	case DRM_FORMAT_XRGB1555:
 	case DRM_FORMAT_XRGB4444:
 	case DRM_FORMAT_YUYV:
 	case DRM_FORMAT_YVYU:
 		return 16;

 	case DRM_FORMAT_BGR888:
 	case DRM_FORMAT_RGB888:
 		return 24;

 	case DRM_FORMAT_ABGR2101010:
 	case DRM_FORMAT_ABGR8888:
 	case DRM_FORMAT_ARGB2101010:
 	case DRM_FORMAT_ARGB8888:
 	case DRM_FORMAT_AYUV:
 	case DRM_FORMAT_BGRA1010102:
 	case DRM_FORMAT_BGRA8888:
 	case DRM_FORMAT_BGRX1010102:
 	case DRM_FORMAT_BGRX8888:
 	case DRM_FORMAT_RGBA1010102:
 	case DRM_FORMAT_RGBA8888:
 	case DRM_FORMAT_RGBX1010102:
 	case DRM_FORMAT_RGBX8888:
 	case DRM_FORMAT_XBGR2101010:
 	case DRM_FORMAT_XBGR8888:
 	case DRM_FORMAT_XRGB2101010:
 	case DRM_FORMAT_XRGB8888:
 		return 32;
 	}

 	fprintf(stderr, "drv: UNKNOWN FORMAT %d\n", format);
 	return 0;
 }

 uint32_t drv_bo_get_stride_in_pixels(struct bo *bo)
 {
 	uint32_t bytes_per_pixel = DIV_ROUND_UP(bpp_from_format(bo->format, 0), 8);
 	return DIV_ROUND_UP(bo->strides[0], bytes_per_pixel);
 }

 /*
  * This function returns the stride for a given format, width and plane.
  */
 uint32_t drv_stride_from_format(uint32_t format, uint32_t width, size_t plane)
 {
 	uint32_t stride = DIV_ROUND_UP(width * bpp_from_format(format, plane), 8);

 	/*
 	 * The stride of Android YV12 buffers is required to be aligned to 16 bytes
 	 * (see <system/graphics.h>).
 	 */
 	if (format == DRM_FORMAT_YVU420_ANDROID)
 		stride = (plane == 0) ? ALIGN(stride, 32) : ALIGN(stride, 16);

 	return stride;
 }

 uint32_t drv_size_from_format(uint32_t format, uint32_t stride, uint32_t height, size_t plane)
 {
 	assert(plane < drv_num_planes_from_format(format));
 	uint32_t vertical_subsampling;

 	switch (format) {
 	case DRM_FORMAT_NV12:
 	case DRM_FORMAT_YVU420:
 	case DRM_FORMAT_YVU420_ANDROID:
 		vertical_subsampling = (plane == 0) ? 1 : 2;
 		break;
 	default:
 		vertical_subsampling = 1;
 	}

 	return stride * DIV_ROUND_UP(height, vertical_subsampling);
 }

 /*
  * This function fills in the buffer object given the driver aligned stride of
  * the first plane, height and a format. This function assumes there is just
  * one kernel buffer per buffer object.
  */
 int drv_bo_from_format(struct bo *bo, uint32_t stride, uint32_t aligned_height, uint32_t format)
 {

 	size_t p, num_planes;
 	uint32_t offset = 0;

 	num_planes = drv_num_planes_from_format(format);
 	assert(num_planes);

 	/*
 	 * HAL_PIXEL_FORMAT_YV12 requires that (see <system/graphics.h>):
 	 *  - the aligned height is same as the buffer's height.
 	 *  - the chroma stride is 16 bytes aligned, i.e., the luma's strides
 	 *    is 32 bytes aligned.
 	 */
 	if (format == DRM_FORMAT_YVU420_ANDROID) {
 		assert(aligned_height == bo->height);
 		assert(stride == ALIGN(stride, 32));
 	}

 	for (p = 0; p < num_planes; p++) {
 		bo->strides[p] = subsample_stride(stride, format, p);
 		bo->sizes[p] = drv_size_from_format(format, bo->strides[p], aligned_height, p);
 		bo->offsets[p] = offset;
 		offset += bo->sizes[p];
 	}

 	bo->total_size = offset;
 	return 0;
 }

 int drv_dumb_bo_create(struct bo *bo, uint32_t width, uint32_t height, uint32_t format,
 		       uint64_t use_flags)
 {
 	int ret;
 	size_t plane;
 	uint32_t aligned_width, aligned_height;
 	struct drm_mode_create_dumb create_dumb;

 	aligned_width = width;
 	aligned_height = height;
 	if (format == DRM_FORMAT_YVU420_ANDROID) {
 		/*
 		 * Align width to 32 pixels, so chroma strides are 16 bytes as
 		 * Android requires.
 		 */
 		aligned_width = ALIGN(width, 32);
 	}

 	if (format == DRM_FORMAT_YVU420_ANDROID || format == DRM_FORMAT_YVU420) {
 		aligned_height = 3 * DIV_ROUND_UP(height, 2);
 	}

 	memset(&create_dumb, 0, sizeof(create_dumb));
 	create_dumb.height = aligned_height;
 	create_dumb.width = aligned_width;
 	create_dumb.bpp = bpp_from_format(format, 0);
 	create_dumb.flags = 0;

 	ret = drmIoctl(bo->drv->fd, DRM_IOCTL_MODE_CREATE_DUMB, &create_dumb);
 	if (ret) {
 		fprintf(stderr, "drv: DRM_IOCTL_MODE_CREATE_DUMB failed\n");
 		return ret;
 	}

 	drv_bo_from_format(bo, create_dumb.pitch, height, format);

 	for (plane = 0; plane < bo->num_planes; plane++)
 		bo->handles[plane].u32 = create_dumb.handle;

 	bo->total_size = create_dumb.size;
 	return 0;
 }

 int drv_dumb_bo_destroy(struct bo *bo)
 {
 	struct drm_mode_destroy_dumb destroy_dumb;
 	int ret;

 	memset(&destroy_dumb, 0, sizeof(destroy_dumb));
 	destroy_dumb.handle = bo->handles[0].u32;

 	ret = drmIoctl(bo->drv->fd, DRM_IOCTL_MODE_DESTROY_DUMB, &destroy_dumb);
 	if (ret) {
 		fprintf(stderr, "drv: DRM_IOCTL_MODE_DESTROY_DUMB failed (handle=%x)\n",
 			bo->handles[0].u32);
 		return ret;
 	}

 	return 0;
 }

 int drv_gem_bo_destroy(struct bo *bo)
 {
 	struct drm_gem_close gem_close;
 	int ret, error = 0;
 	size_t plane, i;

 	for (plane = 0; plane < bo->num_planes; plane++) {
 		for (i = 0; i < plane; i++)
 			if (bo->handles[i].u32 == bo->handles[plane].u32)
 				break;
 		/* Make sure close hasn't already been called on this handle */
 		if (i != plane)
 			continue;

 		memset(&gem_close, 0, sizeof(gem_close));
 		gem_close.handle = bo->handles[plane].u32;

 		ret = drmIoctl(bo->drv->fd, DRM_IOCTL_GEM_CLOSE, &gem_close);
 		if (ret) {
 			fprintf(stderr, "drv: DRM_IOCTL_GEM_CLOSE failed (handle=%x) error %d\n",
 				bo->handles[plane].u32, ret);
 			error = ret;
 		}
 	}

 	return error;
 }

 int drv_prime_bo_import(struct bo *bo, struct drv_import_fd_data *data)
 {
 	int ret;
 	size_t plane;
 	struct drm_prime_handle prime_handle;

 	for (plane = 0; plane < bo->num_planes; plane++) {
 		memset(&prime_handle, 0, sizeof(prime_handle));
 		prime_handle.fd = data->fds[plane];

 		ret = drmIoctl(bo->drv->fd, DRM_IOCTL_PRIME_FD_TO_HANDLE, &prime_handle);

 		if (ret) {
 			fprintf(stderr, "drv: DRM_IOCTL_PRIME_FD_TO_HANDLE failed (fd=%u)\n",
 				prime_handle.fd);

 			/*
 			 * 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;
 			drv_gem_bo_destroy(bo);
 			return ret;
 		}

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

 	for (plane = 0; plane < bo->num_planes; plane++) {
 		pthread_mutex_lock(&bo->drv->driver_lock);
 		drv_increment_reference_count(bo->drv, bo, plane);
 		pthread_mutex_unlock(&bo->drv->driver_lock);
 	}

 	return 0;
 }

 void *drv_dumb_bo_map(struct bo *bo, struct vma *vma, size_t plane, uint32_t map_flags)
 {
 	int ret;
 	size_t i;
 	struct drm_mode_map_dumb map_dumb;

 	memset(&map_dumb, 0, sizeof(map_dumb));
 	map_dumb.handle = bo->handles[plane].u32;

 	ret = drmIoctl(bo->drv->fd, DRM_IOCTL_MODE_MAP_DUMB, &map_dumb);
 	if (ret) {
 		fprintf(stderr, "drv: DRM_IOCTL_MODE_MAP_DUMB failed \n");
 		return MAP_FAILED;
 	}

 	for (i = 0; i < bo->num_planes; i++)
 		if (bo->handles[i].u32 == bo->handles[plane].u32)
 			vma->length += bo->sizes[i];

 	return mmap(0, vma->length, drv_get_prot(map_flags), MAP_SHARED, bo->drv->fd,
 		    map_dumb.offset);
 }

 int drv_bo_munmap(struct bo *bo, struct vma *vma)
 {
 	return munmap(vma->addr, vma->length);
 }

 int drv_mapping_destroy(struct bo *bo)
 {
 	int ret;
 	size_t plane;
 	struct mapping *mapping;
 	uint32_t idx;

 	/*
 	 * This function is called right before the buffer is destroyed. It will free any mappings
 	 * associated with the buffer.
 	 */

 	idx = 0;
 	for (plane = 0; plane < bo->num_planes; plane++) {
 		while (idx < drv_array_size(bo->drv->mappings)) {
 			mapping = (struct mapping *)drv_array_at_idx(bo->drv->mappings, idx);
 			if (mapping->vma->handle != bo->handles[plane].u32) {
 				idx++;
 				continue;
 			}

 			if (!--mapping->vma->refcount) {
 				ret = bo->drv->backend->bo_unmap(bo, mapping->vma);
 				if (ret) {
 					fprintf(stderr, "drv: munmap failed");
 					return ret;
 				}

 				free(mapping->vma);
 			}

 			/* This shrinks and shifts the array, so don't increment idx. */
 			drv_array_remove(bo->drv->mappings, idx);
 		}
 	}

 	return 0;
 }

 int drv_get_prot(uint32_t map_flags)
 {
 	return (BO_MAP_WRITE & map_flags) ? PROT_WRITE | PROT_READ : PROT_READ;
 }

 uintptr_t drv_get_reference_count(struct driver *drv, struct bo *bo, size_t plane)
 {
 	void *count;
 	uintptr_t num = 0;

 	if (!drmHashLookup(drv->buffer_table, bo->handles[plane].u32, &count))
 		num = (uintptr_t)(count);

 	return num;
 }

 void drv_increment_reference_count(struct driver *drv, struct bo *bo, size_t plane)
 {
 	uintptr_t num = drv_get_reference_count(drv, bo, plane);

 	/* If a value isn't in the table, drmHashDelete is a no-op */
 	drmHashDelete(drv->buffer_table, bo->handles[plane].u32);
 	drmHashInsert(drv->buffer_table, bo->handles[plane].u32, (void *)(num + 1));
 }

 void drv_decrement_reference_count(struct driver *drv, struct bo *bo, size_t plane)
 {
 	uintptr_t num = drv_get_reference_count(drv, bo, plane);

 	drmHashDelete(drv->buffer_table, bo->handles[plane].u32);

 	if (num > 0)
 		drmHashInsert(drv->buffer_table, bo->handles[plane].u32, (void *)(num - 1));
 }

 uint32_t drv_log_base2(uint32_t value)
 {
 	int ret = 0;

 	while (value >>= 1)
 		++ret;

 	return ret;
 }

 void drv_add_combinations(struct driver *drv, const uint32_t *formats, uint32_t num_formats,
 			  struct format_metadata *metadata, uint64_t use_flags)
 {
 	uint32_t i;

 	for (i = 0; i < num_formats; i++) {
 		struct combination combo = { .format = formats[i],
 					     .metadata = *metadata,
 					     .use_flags = use_flags };

 		drv_array_append(drv->combos, &combo);
 	}
 }

 void drv_modify_combination(struct driver *drv, uint32_t format, struct format_metadata *metadata,
 			    uint64_t use_flags)
 {
 	uint32_t i;
 	struct combination *combo;
 	/* Attempts to add the specified flags to an existing combination. */
 	for (i = 0; i < drv_array_size(drv->combos); i++) {
 		combo = (struct combination *)drv_array_at_idx(drv->combos, i);
 		if (combo->format == format && combo->metadata.tiling == metadata->tiling &&
 		    combo->metadata.modifier == metadata->modifier)
 			combo->use_flags |= use_flags;
 	}
 }

 struct drv_array *drv_query_kms(struct driver *drv)
 {
 	struct drv_array *kms_items;
 	uint64_t plane_type, use_flag;
 	uint32_t i, j, k;

 	drmModePlanePtr plane;
 	drmModePropertyPtr prop;
 	drmModePlaneResPtr resources;
 	drmModeObjectPropertiesPtr props;

 	kms_items = drv_array_init(sizeof(struct kms_item));
 	if (!kms_items)
 		goto out;

 	/*
 	 * The ability to return universal planes is only complete on
 	 * ChromeOS kernel versions >= v3.18.  The SET_CLIENT_CAP ioctl
 	 * therefore might return an error code, so don't check it.  If it
 	 * fails, it'll just return the plane list as overlay planes, which is
 	 * fine in our case (our drivers already have cursor bits set).
 	 * modetest in libdrm does the same thing.
 	 */
 	drmSetClientCap(drv->fd, DRM_CLIENT_CAP_UNIVERSAL_PLANES, 1);

 	resources = drmModeGetPlaneResources(drv->fd);
 	if (!resources)
 		goto out;

 	for (i = 0; i < resources->count_planes; i++) {
 		plane = drmModeGetPlane(drv->fd, resources->planes[i]);
 		if (!plane)
 			goto out;

 		props = drmModeObjectGetProperties(drv->fd, plane->plane_id, DRM_MODE_OBJECT_PLANE);
 		if (!props)
 			goto out;

 		for (j = 0; j < props->count_props; j++) {
 			prop = drmModeGetProperty(drv->fd, props->props[j]);
 			if (prop) {
 				if (strcmp(prop->name, "type") == 0) {
 					plane_type = props->prop_values[j];
 				}

 				drmModeFreeProperty(prop);
 			}
 		}

 		switch (plane_type) {
 		case DRM_PLANE_TYPE_OVERLAY:
 		case DRM_PLANE_TYPE_PRIMARY:
 			use_flag = BO_USE_SCANOUT;
 			break;
 		case DRM_PLANE_TYPE_CURSOR:
 			use_flag = BO_USE_CURSOR;
 			break;
 		default:
 			assert(0);
 		}

 		for (j = 0; j < plane->count_formats; j++) {
 			bool found = false;
 			for (k = 0; k < drv_array_size(kms_items); k++) {
 				struct kms_item *item = drv_array_at_idx(kms_items, k);
 				if (item->format == plane->formats[j] &&
 				    item->modifier == DRM_FORMAT_MOD_INVALID) {
 					item->use_flags |= use_flag;
 					found = true;
 					break;
 				}
 			}

 			if (!found) {
 				struct kms_item item = { .format = plane->formats[j],
 							 .modifier = DRM_FORMAT_MOD_INVALID,
 							 .use_flags = use_flag };

 				drv_array_append(kms_items, &item);
 			}
 		}

 		drmModeFreeObjectProperties(props);
 		drmModeFreePlane(plane);
 	}

 	drmModeFreePlaneResources(resources);
 out:
 	if (kms_items && !drv_array_size(kms_items)) {
 		drv_array_destroy(kms_items);
 		return NULL;
 	}

 	return kms_items;
 }

 int drv_modify_linear_combinations(struct driver *drv)
 {
 	uint32_t i, j;
 	struct kms_item *item;
 	struct combination *combo;
 	struct drv_array *kms_items;

 	/*
 	 * All current drivers can scanout linear XRGB8888/ARGB8888 as a primary
 	 * plane and as a cursor. Some drivers don't support
 	 * drmModeGetPlaneResources, so add the combination here. Note that the
 	 * kernel disregards the alpha component of ARGB unless it's an overlay
 	 * plane.
 	 */
 	drv_modify_combination(drv, DRM_FORMAT_XRGB8888, &LINEAR_METADATA,
 			       BO_USE_CURSOR | BO_USE_SCANOUT);
 	drv_modify_combination(drv, DRM_FORMAT_ARGB8888, &LINEAR_METADATA,
 			       BO_USE_CURSOR | BO_USE_SCANOUT);

 	kms_items = drv_query_kms(drv);
 	if (!kms_items)
 		return 0;

 	for (i = 0; i < drv_array_size(kms_items); i++) {
 		item = (struct kms_item *)drv_array_at_idx(kms_items, i);
 		for (j = 0; j < drv_array_size(drv->combos); j++) {
 			combo = drv_array_at_idx(drv->combos, j);
 			if (item->format == combo->format)
 				combo->use_flags |= BO_USE_SCANOUT;
 		}
 	}

 	drv_array_destroy(kms_items);
 	return 0;
 }

 /*
  * Pick the best modifier from modifiers, according to the ordering
  * given by modifier_order.
  */
 uint64_t drv_pick_modifier(const uint64_t *modifiers, uint32_t count,
 			   const uint64_t *modifier_order, uint32_t order_count)
 {
 	uint32_t i, j;

 	for (i = 0; i < order_count; i++) {
 		for (j = 0; j < count; j++) {
 			if (modifiers[j] == modifier_order[i]) {
 				return modifiers[j];
 			}
 		}
 	}

 	return DRM_FORMAT_MOD_LINEAR;
 }
	/*
	* 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.
	*/

	#include <assert.h>
	#include <errno.h>
	#include <stdbool.h>
	#include <stdio.h>
	#include <stdlib.h>
	#include <string.h>
	#include <sys/mman.h>
	#include <xf86drm.h>
	#include <xf86drmMode.h>

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

	static uint32_t subsample_stride(uint32_t stride, uint32_t format, size_t plane)
	{

	if (plane != 0) {
	switch (format) {
	case DRM_FORMAT_YVU420:
	case DRM_FORMAT_YVU420_ANDROID:
	stride = DIV_ROUND_UP(stride, 2);
	break;
	}
	}

	return stride;
	}

	static uint32_t bpp_from_format(uint32_t format, size_t plane)
	{
	assert(plane < drv_num_planes_from_format(format));

	switch (format) {
	case DRM_FORMAT_BGR233:
	case DRM_FORMAT_C8:
	case DRM_FORMAT_R8:
	case DRM_FORMAT_RGB332:
	case DRM_FORMAT_YVU420:
	case DRM_FORMAT_YVU420_ANDROID:
	return 8;

	case DRM_FORMAT_NV12:
	case DRM_FORMAT_NV21:
	return (plane == 0) ? 8 : 4;

	case DRM_FORMAT_ABGR1555:
	case DRM_FORMAT_ABGR4444:
	case DRM_FORMAT_ARGB1555:
	case DRM_FORMAT_ARGB4444:
	case DRM_FORMAT_BGR565:
	case DRM_FORMAT_BGRA4444:
	case DRM_FORMAT_BGRA5551:
	case DRM_FORMAT_BGRX4444:
	case DRM_FORMAT_BGRX5551:
	case DRM_FORMAT_GR88:
	case DRM_FORMAT_RG88:
	case DRM_FORMAT_RGB565:
	case DRM_FORMAT_RGBA4444:
	case DRM_FORMAT_RGBA5551:
	case DRM_FORMAT_RGBX4444:
	case DRM_FORMAT_RGBX5551:
	case DRM_FORMAT_UYVY:
	case DRM_FORMAT_VYUY:
	case DRM_FORMAT_XBGR1555:
	case DRM_FORMAT_XBGR4444:
	case DRM_FORMAT_XRGB1555:
	case DRM_FORMAT_XRGB4444:
	case DRM_FORMAT_YUYV:
	case DRM_FORMAT_YVYU:
	return 16;

	case DRM_FORMAT_BGR888:
	case DRM_FORMAT_RGB888:
	return 24;

	case DRM_FORMAT_ABGR2101010:
	case DRM_FORMAT_ABGR8888:
	case DRM_FORMAT_ARGB2101010:
	case DRM_FORMAT_ARGB8888:
	case DRM_FORMAT_AYUV:
	case DRM_FORMAT_BGRA1010102:
	case DRM_FORMAT_BGRA8888:
	case DRM_FORMAT_BGRX1010102:
	case DRM_FORMAT_BGRX8888:
	case DRM_FORMAT_RGBA1010102:
	case DRM_FORMAT_RGBA8888:
	case DRM_FORMAT_RGBX1010102:
	case DRM_FORMAT_RGBX8888:
	case DRM_FORMAT_XBGR2101010:
	case DRM_FORMAT_XBGR8888:
	case DRM_FORMAT_XRGB2101010:
	case DRM_FORMAT_XRGB8888:
	return 32;
	}

	fprintf(stderr, "drv: UNKNOWN FORMAT %d\n", format);
	return 0;
	}

	uint32_t drv_bo_get_stride_in_pixels(struct bo *bo)
	{
	uint32_t bytes_per_pixel = DIV_ROUND_UP(bpp_from_format(bo->format, 0), 8);
	return DIV_ROUND_UP(bo->strides[0], bytes_per_pixel);
	}

	/*
	* This function returns the stride for a given format, width and plane.
	*/
	uint32_t drv_stride_from_format(uint32_t format, uint32_t width, size_t plane)
	{
	uint32_t stride = DIV_ROUND_UP(width * bpp_from_format(format, plane), 8);

	/*
	* The stride of Android YV12 buffers is required to be aligned to 16 bytes
	* (see <system/graphics.h>).
	*/
	if (format == DRM_FORMAT_YVU420_ANDROID)
	stride = (plane == 0) ? ALIGN(stride, 32) : ALIGN(stride, 16);

	return stride;
	}

	uint32_t drv_size_from_format(uint32_t format, uint32_t stride, uint32_t height, size_t plane)
	{
	assert(plane < drv_num_planes_from_format(format));
	uint32_t vertical_subsampling;

	switch (format) {
	case DRM_FORMAT_NV12:
	case DRM_FORMAT_YVU420:
	case DRM_FORMAT_YVU420_ANDROID:
	vertical_subsampling = (plane == 0) ? 1 : 2;
	break;
	default:
	vertical_subsampling = 1;
	}

	return stride * DIV_ROUND_UP(height, vertical_subsampling);
	}

	/*
	* This function fills in the buffer object given the driver aligned stride of
	* the first plane, height and a format. This function assumes there is just
	* one kernel buffer per buffer object.
	*/
	int drv_bo_from_format(struct bo *bo, uint32_t stride, uint32_t aligned_height, uint32_t format)
	{

	size_t p, num_planes;
	uint32_t offset = 0;

	num_planes = drv_num_planes_from_format(format);
	assert(num_planes);

	/*
	* HAL_PIXEL_FORMAT_YV12 requires that (see <system/graphics.h>):
	* - the aligned height is same as the buffer's height.
	* - the chroma stride is 16 bytes aligned, i.e., the luma's strides
	* is 32 bytes aligned.
	*/
	if (format == DRM_FORMAT_YVU420_ANDROID) {
	assert(aligned_height == bo->height);
	assert(stride == ALIGN(stride, 32));
	}

	for (p = 0; p < num_planes; p++) {
	bo->strides[p] = subsample_stride(stride, format, p);
	bo->sizes[p] = drv_size_from_format(format, bo->strides[p], aligned_height, p);
	bo->offsets[p] = offset;
	offset += bo->sizes[p];
	}

	bo->total_size = offset;
	return 0;
	}

	int drv_dumb_bo_create(struct bo *bo, uint32_t width, uint32_t height, uint32_t format,
	uint64_t use_flags)
	{
	int ret;
	size_t plane;
	uint32_t aligned_width, aligned_height;
	struct drm_mode_create_dumb create_dumb;

	aligned_width = width;
	aligned_height = height;
	if (format == DRM_FORMAT_YVU420_ANDROID) {
	/*
	* Align width to 32 pixels, so chroma strides are 16 bytes as
	* Android requires.
	*/
	aligned_width = ALIGN(width, 32);
	}

	if (format == DRM_FORMAT_YVU420_ANDROID \|\| format == DRM_FORMAT_YVU420) {
	aligned_height = 3 * DIV_ROUND_UP(height, 2);
	}

	memset(&create_dumb, 0, sizeof(create_dumb));
	create_dumb.height = aligned_height;
	create_dumb.width = aligned_width;
	create_dumb.bpp = bpp_from_format(format, 0);
	create_dumb.flags = 0;

	ret = drmIoctl(bo->drv->fd, DRM_IOCTL_MODE_CREATE_DUMB, &create_dumb);
	if (ret) {
	fprintf(stderr, "drv: DRM_IOCTL_MODE_CREATE_DUMB failed\n");
	return ret;
	}

	drv_bo_from_format(bo, create_dumb.pitch, height, format);

	for (plane = 0; plane < bo->num_planes; plane++)
	bo->handles[plane].u32 = create_dumb.handle;

	bo->total_size = create_dumb.size;
	return 0;
	}

	int drv_dumb_bo_destroy(struct bo *bo)
	{
	struct drm_mode_destroy_dumb destroy_dumb;
	int ret;

	memset(&destroy_dumb, 0, sizeof(destroy_dumb));
	destroy_dumb.handle = bo->handles[0].u32;

	ret = drmIoctl(bo->drv->fd, DRM_IOCTL_MODE_DESTROY_DUMB, &destroy_dumb);
	if (ret) {
	fprintf(stderr, "drv: DRM_IOCTL_MODE_DESTROY_DUMB failed (handle=%x)\n",
	bo->handles[0].u32);
	return ret;
	}

	return 0;
	}

	int drv_gem_bo_destroy(struct bo *bo)
	{
	struct drm_gem_close gem_close;
	int ret, error = 0;
	size_t plane, i;

	for (plane = 0; plane < bo->num_planes; plane++) {
	for (i = 0; i < plane; i++)
	if (bo->handles[i].u32 == bo->handles[plane].u32)
	break;
	/* Make sure close hasn't already been called on this handle */
	if (i != plane)
	continue;

	memset(&gem_close, 0, sizeof(gem_close));
	gem_close.handle = bo->handles[plane].u32;

	ret = drmIoctl(bo->drv->fd, DRM_IOCTL_GEM_CLOSE, &gem_close);
	if (ret) {
	fprintf(stderr, "drv: DRM_IOCTL_GEM_CLOSE failed (handle=%x) error %d\n",
	bo->handles[plane].u32, ret);
	error = ret;
	}
	}

	return error;
	}

	int drv_prime_bo_import(struct bo bo, struct drv_import_fd_data data)
	{
	int ret;
	size_t plane;
	struct drm_prime_handle prime_handle;

	for (plane = 0; plane < bo->num_planes; plane++) {
	memset(&prime_handle, 0, sizeof(prime_handle));
	prime_handle.fd = data->fds[plane];

	ret = drmIoctl(bo->drv->fd, DRM_IOCTL_PRIME_FD_TO_HANDLE, &prime_handle);

	if (ret) {
	fprintf(stderr, "drv: DRM_IOCTL_PRIME_FD_TO_HANDLE failed (fd=%u)\n",
	prime_handle.fd);

	/*
	* 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;
	drv_gem_bo_destroy(bo);
	return ret;
	}

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

	for (plane = 0; plane < bo->num_planes; plane++) {
	pthread_mutex_lock(&bo->drv->driver_lock);
	drv_increment_reference_count(bo->drv, bo, plane);
	pthread_mutex_unlock(&bo->drv->driver_lock);
	}

	return 0;
	}

	void drv_dumb_bo_map(struct bo bo, struct vma *vma, size_t plane, uint32_t map_flags)
	{
	int ret;
	size_t i;
	struct drm_mode_map_dumb map_dumb;

	memset(&map_dumb, 0, sizeof(map_dumb));
	map_dumb.handle = bo->handles[plane].u32;

	ret = drmIoctl(bo->drv->fd, DRM_IOCTL_MODE_MAP_DUMB, &map_dumb);
	if (ret) {
	fprintf(stderr, "drv: DRM_IOCTL_MODE_MAP_DUMB failed \n");
	return MAP_FAILED;
	}

	for (i = 0; i < bo->num_planes; i++)
	if (bo->handles[i].u32 == bo->handles[plane].u32)
	vma->length += bo->sizes[i];

	return mmap(0, vma->length, drv_get_prot(map_flags), MAP_SHARED, bo->drv->fd,
	map_dumb.offset);
	}

	int drv_bo_munmap(struct bo bo, struct vma vma)
	{
	return munmap(vma->addr, vma->length);
	}

	int drv_mapping_destroy(struct bo *bo)
	{
	int ret;
	size_t plane;
	struct mapping *mapping;
	uint32_t idx;

	/*
	* This function is called right before the buffer is destroyed. It will free any mappings
	* associated with the buffer.
	*/

	idx = 0;
	for (plane = 0; plane < bo->num_planes; plane++) {
	while (idx < drv_array_size(bo->drv->mappings)) {
	mapping = (struct mapping *)drv_array_at_idx(bo->drv->mappings, idx);
	if (mapping->vma->handle != bo->handles[plane].u32) {
	idx++;
	continue;
	}

	if (!--mapping->vma->refcount) {
	ret = bo->drv->backend->bo_unmap(bo, mapping->vma);
	if (ret) {
	fprintf(stderr, "drv: munmap failed");
	return ret;
	}

	free(mapping->vma);
	}

	/* This shrinks and shifts the array, so don't increment idx. */
	drv_array_remove(bo->drv->mappings, idx);
	}
	}

	return 0;
	}

	int drv_get_prot(uint32_t map_flags)
	{
	return (BO_MAP_WRITE & map_flags) ? PROT_WRITE \| PROT_READ : PROT_READ;
	}

	uintptr_t drv_get_reference_count(struct driver drv, struct bo bo, size_t plane)
	{
	void *count;
	uintptr_t num = 0;

	if (!drmHashLookup(drv->buffer_table, bo->handles[plane].u32, &count))
	num = (uintptr_t)(count);

	return num;
	}

	void drv_increment_reference_count(struct driver drv, struct bo bo, size_t plane)
	{
	uintptr_t num = drv_get_reference_count(drv, bo, plane);

	/* If a value isn't in the table, drmHashDelete is a no-op */
	drmHashDelete(drv->buffer_table, bo->handles[plane].u32);
	drmHashInsert(drv->buffer_table, bo->handles[plane].u32, (void *)(num + 1));
	}

	void drv_decrement_reference_count(struct driver drv, struct bo bo, size_t plane)
	{
	uintptr_t num = drv_get_reference_count(drv, bo, plane);

	drmHashDelete(drv->buffer_table, bo->handles[plane].u32);

	if (num > 0)
	drmHashInsert(drv->buffer_table, bo->handles[plane].u32, (void *)(num - 1));
	}

	uint32_t drv_log_base2(uint32_t value)
	{
	int ret = 0;

	while (value >>= 1)
	++ret;

	return ret;
	}

	void drv_add_combinations(struct driver drv, const uint32_t formats, uint32_t num_formats,
	struct format_metadata *metadata, uint64_t use_flags)
	{
	uint32_t i;

	for (i = 0; i < num_formats; i++) {
	struct combination combo = { .format = formats[i],
	.metadata = *metadata,
	.use_flags = use_flags };

	drv_array_append(drv->combos, &combo);
	}
	}

	void drv_modify_combination(struct driver drv, uint32_t format, struct format_metadata metadata,
	uint64_t use_flags)
	{
	uint32_t i;
	struct combination *combo;
	/* Attempts to add the specified flags to an existing combination. */
	for (i = 0; i < drv_array_size(drv->combos); i++) {
	combo = (struct combination *)drv_array_at_idx(drv->combos, i);
	if (combo->format == format && combo->metadata.tiling == metadata->tiling &&
	combo->metadata.modifier == metadata->modifier)
	combo->use_flags \|= use_flags;
	}
	}

	struct drv_array drv_query_kms(struct driver drv)
	{
	struct drv_array *kms_items;
	uint64_t plane_type, use_flag;
	uint32_t i, j, k;

	drmModePlanePtr plane;
	drmModePropertyPtr prop;
	drmModePlaneResPtr resources;
	drmModeObjectPropertiesPtr props;

	kms_items = drv_array_init(sizeof(struct kms_item));
	if (!kms_items)
	goto out;

	/*
	* The ability to return universal planes is only complete on
	* ChromeOS kernel versions >= v3.18. The SET_CLIENT_CAP ioctl
	* therefore might return an error code, so don't check it. If it
	* fails, it'll just return the plane list as overlay planes, which is
	* fine in our case (our drivers already have cursor bits set).
	* modetest in libdrm does the same thing.
	*/
	drmSetClientCap(drv->fd, DRM_CLIENT_CAP_UNIVERSAL_PLANES, 1);

	resources = drmModeGetPlaneResources(drv->fd);
	if (!resources)
	goto out;

	for (i = 0; i < resources->count_planes; i++) {
	plane = drmModeGetPlane(drv->fd, resources->planes[i]);
	if (!plane)
	goto out;

	props = drmModeObjectGetProperties(drv->fd, plane->plane_id, DRM_MODE_OBJECT_PLANE);
	if (!props)
	goto out;

	for (j = 0; j < props->count_props; j++) {
	prop = drmModeGetProperty(drv->fd, props->props[j]);
	if (prop) {
	if (strcmp(prop->name, "type") == 0) {
	plane_type = props->prop_values[j];
	}

	drmModeFreeProperty(prop);
	}
	}

	switch (plane_type) {
	case DRM_PLANE_TYPE_OVERLAY:
	case DRM_PLANE_TYPE_PRIMARY:
	use_flag = BO_USE_SCANOUT;
	break;
	case DRM_PLANE_TYPE_CURSOR:
	use_flag = BO_USE_CURSOR;
	break;
	default:
	assert(0);
	}

	for (j = 0; j < plane->count_formats; j++) {
	bool found = false;
	for (k = 0; k < drv_array_size(kms_items); k++) {
	struct kms_item *item = drv_array_at_idx(kms_items, k);
	if (item->format == plane->formats[j] &&
	item->modifier == DRM_FORMAT_MOD_INVALID) {
	item->use_flags \|= use_flag;
	found = true;
	break;
	}
	}

	if (!found) {
	struct kms_item item = { .format = plane->formats[j],
	.modifier = DRM_FORMAT_MOD_INVALID,
	.use_flags = use_flag };

	drv_array_append(kms_items, &item);
	}
	}

	drmModeFreeObjectProperties(props);
	drmModeFreePlane(plane);
	}

	drmModeFreePlaneResources(resources);
	out:
	if (kms_items && !drv_array_size(kms_items)) {
	drv_array_destroy(kms_items);
	return NULL;
	}

	return kms_items;
	}

	int drv_modify_linear_combinations(struct driver *drv)
	{
	uint32_t i, j;
	struct kms_item *item;
	struct combination *combo;
	struct drv_array *kms_items;

	/*
	* All current drivers can scanout linear XRGB8888/ARGB8888 as a primary
	* plane and as a cursor. Some drivers don't support
	* drmModeGetPlaneResources, so add the combination here. Note that the
	* kernel disregards the alpha component of ARGB unless it's an overlay
	* plane.
	*/
	drv_modify_combination(drv, DRM_FORMAT_XRGB8888, &LINEAR_METADATA,
	BO_USE_CURSOR \| BO_USE_SCANOUT);
	drv_modify_combination(drv, DRM_FORMAT_ARGB8888, &LINEAR_METADATA,
	BO_USE_CURSOR \| BO_USE_SCANOUT);

	kms_items = drv_query_kms(drv);
	if (!kms_items)
	return 0;

	for (i = 0; i < drv_array_size(kms_items); i++) {
	item = (struct kms_item *)drv_array_at_idx(kms_items, i);
	for (j = 0; j < drv_array_size(drv->combos); j++) {
	combo = drv_array_at_idx(drv->combos, j);
	if (item->format == combo->format)
	combo->use_flags \|= BO_USE_SCANOUT;
	}
	}

	drv_array_destroy(kms_items);
	return 0;
	}

	/*
	* Pick the best modifier from modifiers, according to the ordering
	* given by modifier_order.
	*/
	uint64_t drv_pick_modifier(const uint64_t *modifiers, uint32_t count,
	const uint64_t *modifier_order, uint32_t order_count)
	{
	uint32_t i, j;

	for (i = 0; i < order_count; i++) {
	for (j = 0; j < count; j++) {
	if (modifiers[j] == modifier_order[i]) {
	return modifiers[j];
	}
	}
	}

	return DRM_FORMAT_MOD_LINEAR;
	}