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

 /*
  * Copyright 2015 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_MEDIATEK

 // clang-format off
 #include <errno.h>
 #include <fcntl.h>
 #include <inttypes.h>
 #include <poll.h>
 #include <stdio.h>
 #include <string.h>
 #include <sys/mman.h>
 #include <unistd.h>
 #include <xf86drm.h>
 #include <mediatek_drm.h>
 // clang-format on

 #include "drv_helpers.h"
 #include "drv_priv.h"
 #include "util.h"

 #define TILE_TYPE_LINEAR 0

 #if defined(MTK_MT8183) || defined(MTK_MT8186)
 #define SUPPORTS_YUV422
 #endif

 // All platforms except MT8173 should USE_NV12_FOR_HW_VIDEO_DECODING.
 #if defined(MTK_MT8183) || defined(MTK_MT8186) || defined(MTK_MT8192) || defined(MTK_MT8195)
 #define USE_NV12_FOR_HW_VIDEO_DECODING
 #else
 #define DONT_USE_64_ALIGNMENT_FOR_VIDEO_BUFFERS
 #endif

 // For Mali Sigurd based GPUs, the texture unit reads outside the specified texture dimensions.
 // Therefore, certain formats require extra memory padding to its allocated surface to prevent the
 // hardware from reading outside an allocation. For YVU420, we need additional padding for the last
 // chroma plane.
 #if defined(MTK_MT8186)
 #define USE_EXTRA_PADDING_FOR_YVU420
 #endif

 struct mediatek_private_map_data {
 	void *cached_addr;
 	void *gem_addr;
 	int prime_fd;
 };

 static const uint32_t render_target_formats[] = { DRM_FORMAT_ABGR8888, DRM_FORMAT_ARGB8888,
 						  DRM_FORMAT_RGB565, DRM_FORMAT_XBGR8888,
 						  DRM_FORMAT_XRGB8888 };

 // clang-format off
 static const uint32_t texture_source_formats[] = {
 #ifdef SUPPORTS_YUV422
 	DRM_FORMAT_NV21,
 	DRM_FORMAT_YUYV,
 #endif
 	DRM_FORMAT_ABGR2101010,
 	DRM_FORMAT_ABGR16161616F,
 	DRM_FORMAT_NV12,
 	DRM_FORMAT_YVU420,
 	DRM_FORMAT_YVU420_ANDROID
 };

 static const uint32_t video_yuv_formats[] = {
 	DRM_FORMAT_NV21,
 	DRM_FORMAT_NV12,
 	DRM_FORMAT_YUYV,
 	DRM_FORMAT_YVU420,
 	DRM_FORMAT_YVU420_ANDROID
 };
 // clang-format on

 static bool is_video_yuv_format(uint32_t format)
 {
 	size_t i;
 	for (i = 0; i < ARRAY_SIZE(video_yuv_formats); ++i) {
 		if (format == video_yuv_formats[i])
 			return true;
 	}
 	return false;
 }

 static int mediatek_init(struct driver *drv)
 {
 	struct format_metadata metadata;

 	drv_add_combinations(drv, render_target_formats, ARRAY_SIZE(render_target_formats),
 			     &LINEAR_METADATA, BO_USE_RENDER_MASK | BO_USE_SCANOUT);

 	drv_add_combinations(drv, texture_source_formats, ARRAY_SIZE(texture_source_formats),
 			     &LINEAR_METADATA, BO_USE_TEXTURE_MASK);

 	drv_add_combination(drv, DRM_FORMAT_R8, &LINEAR_METADATA, BO_USE_SW_MASK | BO_USE_LINEAR);

 	/* YUYV format for video overlay and camera subsystem. */
 	drv_add_combination(drv, DRM_FORMAT_YUYV, &LINEAR_METADATA,
 			    BO_USE_HW_VIDEO_DECODER | BO_USE_SCANOUT | BO_USE_LINEAR |
 				BO_USE_TEXTURE);

 	/* Android CTS tests require this. */
 	drv_add_combination(drv, DRM_FORMAT_BGR888, &LINEAR_METADATA, BO_USE_SW_MASK);

 	/* Support BO_USE_HW_VIDEO_DECODER for protected content minigbm allocations. */
 	metadata.tiling = TILE_TYPE_LINEAR;
 	metadata.priority = 1;
 	metadata.modifier = DRM_FORMAT_MOD_LINEAR;
 	drv_modify_combination(drv, DRM_FORMAT_YVU420, &metadata, BO_USE_HW_VIDEO_DECODER);
 	drv_modify_combination(drv, DRM_FORMAT_YVU420_ANDROID, &metadata, BO_USE_HW_VIDEO_DECODER);
 #ifdef USE_NV12_FOR_HW_VIDEO_DECODING
 	// TODO(hiroh): Switch to use NV12 for video decoder on MT8173 as well.
 	drv_modify_combination(drv, DRM_FORMAT_NV12, &metadata, BO_USE_HW_VIDEO_DECODER);
 #endif

 	/*
 	 * R8 format is used for Android's HAL_PIXEL_FORMAT_BLOB for input/output from
 	 * hardware decoder/encoder.
 	 */
 	drv_modify_combination(drv, DRM_FORMAT_R8, &metadata,
 			       BO_USE_HW_VIDEO_DECODER | BO_USE_HW_VIDEO_ENCODER |
 				   BO_USE_CAMERA_READ | BO_USE_CAMERA_WRITE |
 				   BO_USE_GPU_DATA_BUFFER | BO_USE_SENSOR_DIRECT_DATA);

 	/* NV12 format for encoding and display. */
 	drv_modify_combination(drv, DRM_FORMAT_NV12, &metadata,
 			       BO_USE_SCANOUT | BO_USE_HW_VIDEO_ENCODER | BO_USE_CAMERA_READ |
 				   BO_USE_CAMERA_WRITE);

 #ifdef MTK_MT8183
 	/* Only for MT8183 Camera subsystem */
 	drv_modify_combination(drv, DRM_FORMAT_NV21, &metadata,
 			       BO_USE_CAMERA_READ | BO_USE_CAMERA_WRITE);
 	drv_modify_combination(drv, DRM_FORMAT_YUYV, &metadata,
 			       BO_USE_CAMERA_READ | BO_USE_CAMERA_WRITE);
 	drv_modify_combination(drv, DRM_FORMAT_YVU420, &metadata,
 			       BO_USE_CAMERA_READ | BO_USE_CAMERA_WRITE);
 	/* Private formats for private reprocessing in camera */
 	drv_add_combination(drv, DRM_FORMAT_MTISP_SXYZW10, &metadata,
 			    BO_USE_CAMERA_READ | BO_USE_CAMERA_WRITE | BO_USE_SW_MASK);
 #endif

 	return drv_modify_linear_combinations(drv);
 }

 static int mediatek_bo_create_with_modifiers(struct bo *bo, uint32_t width, uint32_t height,
 					     uint32_t format, const uint64_t *modifiers,
 					     uint32_t count)
 {
 	int ret;
 	size_t plane;
 	uint32_t stride;
 	struct drm_mtk_gem_create gem_create = { 0 };
 	/*
 	 * We identify the ChromeOS Camera App buffers via these two USE flags. Those buffers need
 	 * the same alignment as the video hardware encoding.
 	 */
 	const bool is_camera_preview =
 	    (bo->meta.use_flags & BO_USE_SCANOUT) && (bo->meta.use_flags & BO_USE_CAMERA_WRITE);

 	if (!drv_has_modifier(modifiers, count, DRM_FORMAT_MOD_LINEAR)) {
 		errno = EINVAL;
 		drv_loge("no usable modifier found\n");
 		return -EINVAL;
 	}

 	/*
 	 * Since the ARM L1 cache line size is 64 bytes, align to that as a
 	 * performance optimization, except for video buffers on certain platforms,
 	 * these should only be accessed from the GPU and VCODEC subsystems (maybe
 	 * also MDP), so it's better to align to macroblocks.
 	 */
 	stride = drv_stride_from_format(format, width, 0);
 #ifdef DONT_USE_64_ALIGNMENT_FOR_VIDEO_BUFFERS
 	const uint32_t alignment = is_video_yuv_format(format) ? 16 : 64;
 	stride = ALIGN(stride, alignment);
 #else
 	stride = ALIGN(stride, 64);
 #endif

 	if ((bo->meta.use_flags & BO_USE_HW_VIDEO_ENCODER) || is_camera_preview) {
 		uint32_t aligned_height = ALIGN(height, 32);
 		uint32_t padding[DRV_MAX_PLANES] = { 0 };

 		for (plane = 0; plane < bo->meta.num_planes; ++plane) {
 			uint32_t plane_stride = drv_stride_from_format(format, stride, plane);
 			padding[plane] = plane_stride *
 					 (32 / drv_vertical_subsampling_from_format(format, plane));
 		}

 		drv_bo_from_format_and_padding(bo, stride, aligned_height, format, padding);
 	} else {
 #ifdef SUPPORTS_YUV422
 		/*
 		 * JPEG Encoder Accelerator requires 16x16 alignment. We want the buffer
 		 * from camera can be put in JEA directly so align the height to 16
 		 * bytes.
 		 */
 		if (format == DRM_FORMAT_NV12)
 			height = ALIGN(height, 16);
 #endif
 		drv_bo_from_format(bo, stride, height, format);

 #ifdef USE_EXTRA_PADDING_FOR_YVU420
 		/* Do the fix after drv_bo_from_format to avoid extra calculations. */
 		if ((format == DRM_FORMAT_YVU420 || format == DRM_FORMAT_YVU420_ANDROID) &&
 		    (bo->meta.use_flags & BO_USE_TEXTURE)) {
 			const size_t last_plane = bo->meta.num_planes - 1;
 			uint32_t padded_last_plane_size = drv_size_from_format(
 			    format, bo->meta.strides[last_plane], ALIGN(height, 4), last_plane);
 			bo->meta.total_size += padded_last_plane_size - bo->meta.sizes[last_plane];

 			/* b/239243515 workaround starts here */
 			height = ALIGN(height, 4);
 			bo->meta.total_size = 0;
 			for (plane = 0; plane < bo->meta.num_planes; plane++) {
 				bo->meta.total_size += drv_size_from_format(
 				    format, bo->meta.strides[plane], height, plane);
 			}
 			/* b/239243515 workaround ends here */
 		}
 #endif
 	}

 	gem_create.size = bo->meta.total_size;

 	ret = drmIoctl(bo->drv->fd, DRM_IOCTL_MTK_GEM_CREATE, &gem_create);
 	if (ret) {
 		drv_loge("DRM_IOCTL_MTK_GEM_CREATE failed (size=%" PRIu64 ")\n", gem_create.size);
 		return -errno;
 	}

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

 	return 0;
 }

 static int mediatek_bo_create(struct bo *bo, uint32_t width, uint32_t height, uint32_t format,
 			      uint64_t use_flags)
 {
 	uint64_t modifiers[] = { DRM_FORMAT_MOD_LINEAR };
 	return mediatek_bo_create_with_modifiers(bo, width, height, format, modifiers,
 						 ARRAY_SIZE(modifiers));
 }

 static void *mediatek_bo_map(struct bo *bo, struct vma *vma, size_t plane, uint32_t map_flags)
 {
 	int ret, prime_fd;
 	struct drm_mtk_gem_map_off gem_map = { 0 };
 	struct mediatek_private_map_data *priv;
 	void *addr = NULL;

 	gem_map.handle = bo->handles[0].u32;

 	ret = drmIoctl(bo->drv->fd, DRM_IOCTL_MTK_GEM_MAP_OFFSET, &gem_map);
 	if (ret) {
 		drv_loge("DRM_IOCTL_MTK_GEM_MAP_OFFSET failed\n");
 		return MAP_FAILED;
 	}

 	prime_fd = drv_bo_get_plane_fd(bo, 0);
 	if (prime_fd < 0) {
 		drv_loge("Failed to get a prime fd\n");
 		return MAP_FAILED;
 	}

 	addr = mmap(0, bo->meta.total_size, drv_get_prot(map_flags), MAP_SHARED, bo->drv->fd,
 		    gem_map.offset);
 	if (addr == MAP_FAILED)
 		goto out_close_prime_fd;

 	vma->length = bo->meta.total_size;

 	priv = calloc(1, sizeof(*priv));
 	if (!priv)
 		goto out_unmap_addr;

 	if (bo->meta.use_flags & BO_USE_RENDERSCRIPT) {
 		priv->cached_addr = calloc(1, bo->meta.total_size);
 		if (!priv->cached_addr)
 			goto out_free_priv;

 		priv->gem_addr = addr;
 		addr = priv->cached_addr;
 	}

 	priv->prime_fd = prime_fd;
 	vma->priv = priv;

 	return addr;

 out_free_priv:
 	free(priv);
 out_unmap_addr:
 	munmap(addr, bo->meta.total_size);
 out_close_prime_fd:
 	close(prime_fd);
 	return MAP_FAILED;
 }

 static int mediatek_bo_unmap(struct bo *bo, struct vma *vma)
 {
 	if (vma->priv) {
 		struct mediatek_private_map_data *priv = vma->priv;

 		if (priv->cached_addr) {
 			vma->addr = priv->gem_addr;
 			free(priv->cached_addr);
 		}

 		close(priv->prime_fd);
 		free(priv);
 		vma->priv = NULL;
 	}

 	return munmap(vma->addr, vma->length);
 }

 static int mediatek_bo_invalidate(struct bo *bo, struct mapping *mapping)
 {
 	struct mediatek_private_map_data *priv = mapping->vma->priv;

 	if (priv) {
 		struct pollfd fds = {
 			.fd = priv->prime_fd,
 		};

 		if (mapping->vma->map_flags & BO_MAP_WRITE)
 			fds.events |= POLLOUT;

 		if (mapping->vma->map_flags & BO_MAP_READ)
 			fds.events |= POLLIN;

 		poll(&fds, 1, -1);
 		if (fds.revents != fds.events)
 			drv_loge("poll prime_fd failed\n");

 		if (priv->cached_addr)
 			memcpy(priv->cached_addr, priv->gem_addr, bo->meta.total_size);
 	}

 	return 0;
 }

 static int mediatek_bo_flush(struct bo *bo, struct mapping *mapping)
 {
 	struct mediatek_private_map_data *priv = mapping->vma->priv;
 	if (priv && priv->cached_addr && (mapping->vma->map_flags & BO_MAP_WRITE))
 		memcpy(priv->gem_addr, priv->cached_addr, bo->meta.total_size);

 	return 0;
 }

 static void mediatek_resolve_format_and_use_flags(struct driver *drv, uint32_t format,
 						  uint64_t use_flags, uint32_t *out_format,
 						  uint64_t *out_use_flags)
 {
 	*out_format = format;
 	*out_use_flags = use_flags;
 	switch (format) {
 	case DRM_FORMAT_FLEX_IMPLEMENTATION_DEFINED:
 #ifdef MTK_MT8183
 		/* Only MT8183 Camera subsystem offers private reprocessing
 		 * capability. CAMERA_READ indicates the buffer is intended for
 		 * reprocessing and hence given the private format for MTK. */
 		if (use_flags & BO_USE_CAMERA_READ) {
 			*out_format = DRM_FORMAT_MTISP_SXYZW10;
 			break;
 		}
 #endif
 		if (use_flags & BO_USE_CAMERA_WRITE) {
 			*out_format = DRM_FORMAT_NV12;
 			break;
 		}

 		/* HACK: See b/28671744 */
 		*out_format = DRM_FORMAT_XBGR8888;
 		*out_use_flags &= ~BO_USE_HW_VIDEO_ENCODER;
 		break;
 	case DRM_FORMAT_FLEX_YCbCr_420_888:
 #ifdef USE_NV12_FOR_HW_VIDEO_DECODING
 		// TODO(hiroh): Switch to use NV12 for video decoder on MT8173 as well.
 		if (use_flags & (BO_USE_HW_VIDEO_DECODER)) {
 			*out_format = DRM_FORMAT_NV12;
 			break;
 		}
 #endif
 		if (use_flags &
 		    (BO_USE_CAMERA_READ | BO_USE_CAMERA_WRITE | BO_USE_HW_VIDEO_ENCODER)) {
 			*out_format = DRM_FORMAT_NV12;
 			break;
 		}

 		/* HACK: See b/139714614 */
 		*out_format = DRM_FORMAT_YVU420;
 		*out_use_flags &= ~BO_USE_SCANOUT;
 		break;
 	default:
 		break;
 	}
 	/* Mediatek doesn't support YUV overlays */
 	if (is_video_yuv_format(format))
 		*out_use_flags &= ~BO_USE_SCANOUT;
 }

 const struct backend backend_mediatek = {
 	.name = "mediatek",
 	.init = mediatek_init,
 	.bo_create = mediatek_bo_create,
 	.bo_create_with_modifiers = mediatek_bo_create_with_modifiers,
 	.bo_destroy = drv_gem_bo_destroy,
 	.bo_import = drv_prime_bo_import,
 	.bo_map = mediatek_bo_map,
 	.bo_unmap = mediatek_bo_unmap,
 	.bo_invalidate = mediatek_bo_invalidate,
 	.bo_flush = mediatek_bo_flush,
 	.resolve_format_and_use_flags = mediatek_resolve_format_and_use_flags,
 };

 #endif
	/*
	* Copyright 2015 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_MEDIATEK

	// clang-format off
	#include <errno.h>
	#include <fcntl.h>
	#include <inttypes.h>
	#include <poll.h>
	#include <stdio.h>
	#include <string.h>
	#include <sys/mman.h>
	#include <unistd.h>
	#include <xf86drm.h>
	#include <mediatek_drm.h>
	// clang-format on

	#include "drv_helpers.h"
	#include "drv_priv.h"
	#include "util.h"

	#define TILE_TYPE_LINEAR 0

	#if defined(MTK_MT8183) \|\| defined(MTK_MT8186)
	#define SUPPORTS_YUV422
	#endif

	// All platforms except MT8173 should USE_NV12_FOR_HW_VIDEO_DECODING.
	#if defined(MTK_MT8183) \|\| defined(MTK_MT8186) \|\| defined(MTK_MT8192) \|\| defined(MTK_MT8195)
	#define USE_NV12_FOR_HW_VIDEO_DECODING
	#else
	#define DONT_USE_64_ALIGNMENT_FOR_VIDEO_BUFFERS
	#endif

	// For Mali Sigurd based GPUs, the texture unit reads outside the specified texture dimensions.
	// Therefore, certain formats require extra memory padding to its allocated surface to prevent the
	// hardware from reading outside an allocation. For YVU420, we need additional padding for the last
	// chroma plane.
	#if defined(MTK_MT8186)
	#define USE_EXTRA_PADDING_FOR_YVU420
	#endif

	struct mediatek_private_map_data {
	void *cached_addr;
	void *gem_addr;
	int prime_fd;
	};

	static const uint32_t render_target_formats[] = { DRM_FORMAT_ABGR8888, DRM_FORMAT_ARGB8888,
	DRM_FORMAT_RGB565, DRM_FORMAT_XBGR8888,
	DRM_FORMAT_XRGB8888 };

	// clang-format off
	static const uint32_t texture_source_formats[] = {
	#ifdef SUPPORTS_YUV422
	DRM_FORMAT_NV21,
	DRM_FORMAT_YUYV,
	#endif
	DRM_FORMAT_ABGR2101010,
	DRM_FORMAT_ABGR16161616F,
	DRM_FORMAT_NV12,
	DRM_FORMAT_YVU420,
	DRM_FORMAT_YVU420_ANDROID
	};

	static const uint32_t video_yuv_formats[] = {
	DRM_FORMAT_NV21,
	DRM_FORMAT_NV12,
	DRM_FORMAT_YUYV,
	DRM_FORMAT_YVU420,
	DRM_FORMAT_YVU420_ANDROID
	};
	// clang-format on

	static bool is_video_yuv_format(uint32_t format)
	{
	size_t i;
	for (i = 0; i < ARRAY_SIZE(video_yuv_formats); ++i) {
	if (format == video_yuv_formats[i])
	return true;
	}
	return false;
	}

	static int mediatek_init(struct driver *drv)
	{
	struct format_metadata metadata;

	drv_add_combinations(drv, render_target_formats, ARRAY_SIZE(render_target_formats),
	&LINEAR_METADATA, BO_USE_RENDER_MASK \| BO_USE_SCANOUT);

	drv_add_combinations(drv, texture_source_formats, ARRAY_SIZE(texture_source_formats),
	&LINEAR_METADATA, BO_USE_TEXTURE_MASK);

	drv_add_combination(drv, DRM_FORMAT_R8, &LINEAR_METADATA, BO_USE_SW_MASK \| BO_USE_LINEAR);

	/* YUYV format for video overlay and camera subsystem. */
	drv_add_combination(drv, DRM_FORMAT_YUYV, &LINEAR_METADATA,
	BO_USE_HW_VIDEO_DECODER \| BO_USE_SCANOUT \| BO_USE_LINEAR \|
	BO_USE_TEXTURE);

	/* Android CTS tests require this. */
	drv_add_combination(drv, DRM_FORMAT_BGR888, &LINEAR_METADATA, BO_USE_SW_MASK);

	/* Support BO_USE_HW_VIDEO_DECODER for protected content minigbm allocations. */
	metadata.tiling = TILE_TYPE_LINEAR;
	metadata.priority = 1;
	metadata.modifier = DRM_FORMAT_MOD_LINEAR;
	drv_modify_combination(drv, DRM_FORMAT_YVU420, &metadata, BO_USE_HW_VIDEO_DECODER);
	drv_modify_combination(drv, DRM_FORMAT_YVU420_ANDROID, &metadata, BO_USE_HW_VIDEO_DECODER);
	#ifdef USE_NV12_FOR_HW_VIDEO_DECODING
	// TODO(hiroh): Switch to use NV12 for video decoder on MT8173 as well.
	drv_modify_combination(drv, DRM_FORMAT_NV12, &metadata, BO_USE_HW_VIDEO_DECODER);
	#endif

	/*
	* R8 format is used for Android's HAL_PIXEL_FORMAT_BLOB for input/output from
	* hardware decoder/encoder.
	*/
	drv_modify_combination(drv, DRM_FORMAT_R8, &metadata,
	BO_USE_HW_VIDEO_DECODER \| BO_USE_HW_VIDEO_ENCODER \|
	BO_USE_CAMERA_READ \| BO_USE_CAMERA_WRITE \|
	BO_USE_GPU_DATA_BUFFER \| BO_USE_SENSOR_DIRECT_DATA);

	/* NV12 format for encoding and display. */
	drv_modify_combination(drv, DRM_FORMAT_NV12, &metadata,
	BO_USE_SCANOUT \| BO_USE_HW_VIDEO_ENCODER \| BO_USE_CAMERA_READ \|
	BO_USE_CAMERA_WRITE);

	#ifdef MTK_MT8183
	/* Only for MT8183 Camera subsystem */
	drv_modify_combination(drv, DRM_FORMAT_NV21, &metadata,
	BO_USE_CAMERA_READ \| BO_USE_CAMERA_WRITE);
	drv_modify_combination(drv, DRM_FORMAT_YUYV, &metadata,
	BO_USE_CAMERA_READ \| BO_USE_CAMERA_WRITE);
	drv_modify_combination(drv, DRM_FORMAT_YVU420, &metadata,
	BO_USE_CAMERA_READ \| BO_USE_CAMERA_WRITE);
	/* Private formats for private reprocessing in camera */
	drv_add_combination(drv, DRM_FORMAT_MTISP_SXYZW10, &metadata,
	BO_USE_CAMERA_READ \| BO_USE_CAMERA_WRITE \| BO_USE_SW_MASK);
	#endif

	return drv_modify_linear_combinations(drv);
	}

	static int mediatek_bo_create_with_modifiers(struct bo *bo, uint32_t width, uint32_t height,
	uint32_t format, const uint64_t *modifiers,
	uint32_t count)
	{
	int ret;
	size_t plane;
	uint32_t stride;
	struct drm_mtk_gem_create gem_create = { 0 };
	/*
	* We identify the ChromeOS Camera App buffers via these two USE flags. Those buffers need
	* the same alignment as the video hardware encoding.
	*/
	const bool is_camera_preview =
	(bo->meta.use_flags & BO_USE_SCANOUT) && (bo->meta.use_flags & BO_USE_CAMERA_WRITE);

	if (!drv_has_modifier(modifiers, count, DRM_FORMAT_MOD_LINEAR)) {
	errno = EINVAL;
	drv_loge("no usable modifier found\n");
	return -EINVAL;
	}

	/*
	* Since the ARM L1 cache line size is 64 bytes, align to that as a
	* performance optimization, except for video buffers on certain platforms,
	* these should only be accessed from the GPU and VCODEC subsystems (maybe
	* also MDP), so it's better to align to macroblocks.
	*/
	stride = drv_stride_from_format(format, width, 0);
	#ifdef DONT_USE_64_ALIGNMENT_FOR_VIDEO_BUFFERS
	const uint32_t alignment = is_video_yuv_format(format) ? 16 : 64;
	stride = ALIGN(stride, alignment);
	#else
	stride = ALIGN(stride, 64);
	#endif

	if ((bo->meta.use_flags & BO_USE_HW_VIDEO_ENCODER) \|\| is_camera_preview) {
	uint32_t aligned_height = ALIGN(height, 32);
	uint32_t padding[DRV_MAX_PLANES] = { 0 };

	for (plane = 0; plane < bo->meta.num_planes; ++plane) {
	uint32_t plane_stride = drv_stride_from_format(format, stride, plane);
	padding[plane] = plane_stride *
	(32 / drv_vertical_subsampling_from_format(format, plane));
	}

	drv_bo_from_format_and_padding(bo, stride, aligned_height, format, padding);
	} else {
	#ifdef SUPPORTS_YUV422
	/*
	* JPEG Encoder Accelerator requires 16x16 alignment. We want the buffer
	* from camera can be put in JEA directly so align the height to 16
	* bytes.
	*/
	if (format == DRM_FORMAT_NV12)
	height = ALIGN(height, 16);
	#endif
	drv_bo_from_format(bo, stride, height, format);

	#ifdef USE_EXTRA_PADDING_FOR_YVU420
	/* Do the fix after drv_bo_from_format to avoid extra calculations. */
	if ((format == DRM_FORMAT_YVU420 \|\| format == DRM_FORMAT_YVU420_ANDROID) &&
	(bo->meta.use_flags & BO_USE_TEXTURE)) {
	const size_t last_plane = bo->meta.num_planes - 1;
	uint32_t padded_last_plane_size = drv_size_from_format(
	format, bo->meta.strides[last_plane], ALIGN(height, 4), last_plane);
	bo->meta.total_size += padded_last_plane_size - bo->meta.sizes[last_plane];

	/* b/239243515 workaround starts here */
	height = ALIGN(height, 4);
	bo->meta.total_size = 0;
	for (plane = 0; plane < bo->meta.num_planes; plane++) {
	bo->meta.total_size += drv_size_from_format(
	format, bo->meta.strides[plane], height, plane);
	}
	/* b/239243515 workaround ends here */
	}
	#endif
	}

	gem_create.size = bo->meta.total_size;

	ret = drmIoctl(bo->drv->fd, DRM_IOCTL_MTK_GEM_CREATE, &gem_create);
	if (ret) {
	drv_loge("DRM_IOCTL_MTK_GEM_CREATE failed (size=%" PRIu64 ")\n", gem_create.size);
	return -errno;
	}

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

	return 0;
	}

	static int mediatek_bo_create(struct bo *bo, uint32_t width, uint32_t height, uint32_t format,
	uint64_t use_flags)
	{
	uint64_t modifiers[] = { DRM_FORMAT_MOD_LINEAR };
	return mediatek_bo_create_with_modifiers(bo, width, height, format, modifiers,
	ARRAY_SIZE(modifiers));
	}

	static void mediatek_bo_map(struct bo bo, struct vma *vma, size_t plane, uint32_t map_flags)
	{
	int ret, prime_fd;
	struct drm_mtk_gem_map_off gem_map = { 0 };
	struct mediatek_private_map_data *priv;
	void *addr = NULL;

	gem_map.handle = bo->handles[0].u32;

	ret = drmIoctl(bo->drv->fd, DRM_IOCTL_MTK_GEM_MAP_OFFSET, &gem_map);
	if (ret) {
	drv_loge("DRM_IOCTL_MTK_GEM_MAP_OFFSET failed\n");
	return MAP_FAILED;
	}

	prime_fd = drv_bo_get_plane_fd(bo, 0);
	if (prime_fd < 0) {
	drv_loge("Failed to get a prime fd\n");
	return MAP_FAILED;
	}

	addr = mmap(0, bo->meta.total_size, drv_get_prot(map_flags), MAP_SHARED, bo->drv->fd,
	gem_map.offset);
	if (addr == MAP_FAILED)
	goto out_close_prime_fd;

	vma->length = bo->meta.total_size;

	priv = calloc(1, sizeof(*priv));
	if (!priv)
	goto out_unmap_addr;

	if (bo->meta.use_flags & BO_USE_RENDERSCRIPT) {
	priv->cached_addr = calloc(1, bo->meta.total_size);
	if (!priv->cached_addr)
	goto out_free_priv;

	priv->gem_addr = addr;
	addr = priv->cached_addr;
	}

	priv->prime_fd = prime_fd;
	vma->priv = priv;

	return addr;

	out_free_priv:
	free(priv);
	out_unmap_addr:
	munmap(addr, bo->meta.total_size);
	out_close_prime_fd:
	close(prime_fd);
	return MAP_FAILED;
	}

	static int mediatek_bo_unmap(struct bo bo, struct vma vma)
	{
	if (vma->priv) {
	struct mediatek_private_map_data *priv = vma->priv;

	if (priv->cached_addr) {
	vma->addr = priv->gem_addr;
	free(priv->cached_addr);
	}

	close(priv->prime_fd);
	free(priv);
	vma->priv = NULL;
	}

	return munmap(vma->addr, vma->length);
	}

	static int mediatek_bo_invalidate(struct bo bo, struct mapping mapping)
	{
	struct mediatek_private_map_data *priv = mapping->vma->priv;

	if (priv) {
	struct pollfd fds = {
	.fd = priv->prime_fd,
	};

	if (mapping->vma->map_flags & BO_MAP_WRITE)
	fds.events \|= POLLOUT;

	if (mapping->vma->map_flags & BO_MAP_READ)
	fds.events \|= POLLIN;

	poll(&fds, 1, -1);
	if (fds.revents != fds.events)
	drv_loge("poll prime_fd failed\n");

	if (priv->cached_addr)
	memcpy(priv->cached_addr, priv->gem_addr, bo->meta.total_size);
	}

	return 0;
	}

	static int mediatek_bo_flush(struct bo bo, struct mapping mapping)
	{
	struct mediatek_private_map_data *priv = mapping->vma->priv;
	if (priv && priv->cached_addr && (mapping->vma->map_flags & BO_MAP_WRITE))
	memcpy(priv->gem_addr, priv->cached_addr, bo->meta.total_size);

	return 0;
	}

	static void mediatek_resolve_format_and_use_flags(struct driver *drv, uint32_t format,
	uint64_t use_flags, uint32_t *out_format,
	uint64_t *out_use_flags)
	{
	*out_format = format;
	*out_use_flags = use_flags;
	switch (format) {
	case DRM_FORMAT_FLEX_IMPLEMENTATION_DEFINED:
	#ifdef MTK_MT8183
	/* Only MT8183 Camera subsystem offers private reprocessing
	* capability. CAMERA_READ indicates the buffer is intended for
	* reprocessing and hence given the private format for MTK. */
	if (use_flags & BO_USE_CAMERA_READ) {
	*out_format = DRM_FORMAT_MTISP_SXYZW10;
	break;
	}
	#endif
	if (use_flags & BO_USE_CAMERA_WRITE) {
	*out_format = DRM_FORMAT_NV12;
	break;
	}

	/* HACK: See b/28671744 */
	*out_format = DRM_FORMAT_XBGR8888;
	*out_use_flags &= ~BO_USE_HW_VIDEO_ENCODER;
	break;
	case DRM_FORMAT_FLEX_YCbCr_420_888:
	#ifdef USE_NV12_FOR_HW_VIDEO_DECODING
	// TODO(hiroh): Switch to use NV12 for video decoder on MT8173 as well.
	if (use_flags & (BO_USE_HW_VIDEO_DECODER)) {
	*out_format = DRM_FORMAT_NV12;
	break;
	}
	#endif
	if (use_flags &
	(BO_USE_CAMERA_READ \| BO_USE_CAMERA_WRITE \| BO_USE_HW_VIDEO_ENCODER)) {
	*out_format = DRM_FORMAT_NV12;
	break;
	}

	/* HACK: See b/139714614 */
	*out_format = DRM_FORMAT_YVU420;
	*out_use_flags &= ~BO_USE_SCANOUT;
	break;
	default:
	break;
	}
	/* Mediatek doesn't support YUV overlays */
	if (is_video_yuv_format(format))
	*out_use_flags &= ~BO_USE_SCANOUT;
	}

	const struct backend backend_mediatek = {
	.name = "mediatek",
	.init = mediatek_init,
	.bo_create = mediatek_bo_create,
	.bo_create_with_modifiers = mediatek_bo_create_with_modifiers,
	.bo_destroy = drv_gem_bo_destroy,
	.bo_import = drv_prime_bo_import,
	.bo_map = mediatek_bo_map,
	.bo_unmap = mediatek_bo_unmap,
	.bo_invalidate = mediatek_bo_invalidate,
	.bo_flush = mediatek_bo_flush,
	.resolve_format_and_use_flags = mediatek_resolve_format_and_use_flags,
	};

	#endif