bufferinfo/BufferInfoMapperMetadata.cpp

/*
 * Copyright (C) 2020 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#if __ANDROID_API__ >= 30

#define LOG_TAG "drmhwc"

#include "BufferInfoMapperMetadata.h"

#include <drm/drm_fourcc.h>
#include <ui/GraphicBufferMapper.h>
#include <xf86drm.h>
#include <xf86drmMode.h>

#include <cinttypes>

#include "utils/log.h"

namespace android {

namespace {

std::optional<std::pair<uint32_t, uint32_t>> GetAlignedDimensions(
    const ui::PlaneLayout &layout) {
  if (layout.sampleIncrementInBits == 0 || layout.strideInBytes == 0) {
    ALOGW("Invalid plane layout");
    return std::nullopt;
  }

  constexpr uint32_t kBitsPerByte = 8;
  return std::pair{layout.strideInBytes * kBitsPerByte /
                       layout.sampleIncrementInBits,
                   layout.totalSizeInBytes / layout.strideInBytes};
}

}  // namespace

BufferInfoGetter *BufferInfoMapperMetadata::CreateInstance() {
  if (GraphicBufferMapper::getInstance().getMapperVersion() <
      GraphicBufferMapper::GRALLOC_4)
    return nullptr;

  return new BufferInfoMapperMetadata();
}

/* The implementation below makes assumptions on the order and number of file
 * descriptors that Gralloc places in the native_handle_t and as such it very
 * likely needs to be adapted to match the particular Gralloc implementation
 * used in the system. For this reason it is been declared as a weak symbol,
 * so that it can be overridden.
 */
int __attribute__((weak))
BufferInfoMapperMetadata::GetFds(buffer_handle_t handle, BufferInfo *bo) {
  int fd_index = 0;

  if (handle->numFds <= 0) {
    ALOGE("Handle has no fds");
    return android::BAD_VALUE;
  }

  for (int i = 0; i < kBufferMaxPlanes; i++) {
    /* If no size, we're out of usable planes */
    if (bo->sizes[i] <= 0) {
      if (i == 0) {
        ALOGE("Bad handle metadata");
        return android::BAD_VALUE;
      }
      break;
    }

    /*
     * If the offset is zero, its multi-buffer
     * so move to the next fd
     */
    if (i != 0 && bo->offsets[i] == 0) {
      fd_index++;
      if (fd_index >= handle->numFds) {
        ALOGE("Handle has no more fds");
        return android::BAD_VALUE;
      }
    }

    bo->prime_fds[i] = handle->data[fd_index];
    if (bo->prime_fds[i] <= 0) {
      ALOGE("Invalid prime fd");
      return android::BAD_VALUE;
    }
  }

  return 0;
}

auto BufferInfoMapperMetadata::GetBoInfo(buffer_handle_t handle)
    -> std::optional<BufferInfo> {
  GraphicBufferMapper &mapper = GraphicBufferMapper::getInstance();
  if (handle == nullptr)
    return {};

  BufferInfo bi{};

  int err = mapper.getPixelFormatFourCC(handle, &bi.format);
  if (err != 0) {
    ALOGE("Failed to get FourCC format err=%d", err);
    return {};
  }

  err = mapper.getPixelFormatModifier(handle, &bi.modifiers[0]);
  if (err != 0) {
    ALOGE("Failed to get DRM Modifier err=%d", err);
    return {};
  }

  uint64_t width = 0;
  err = mapper.getWidth(handle, &width);
  if (err != 0) {
    ALOGE("Failed to get Width err=%d", err);
    return {};
  }
  bi.width = static_cast<uint32_t>(width);

  uint64_t height = 0;
  err = mapper.getHeight(handle, &height);
  if (err != 0) {
    ALOGE("Failed to get Height err=%d", err);
    return {};
  }
  bi.height = static_cast<uint32_t>(height);

  std::vector<ui::PlaneLayout> layouts;
  err = mapper.getPlaneLayouts(handle, &layouts);
  if (err != 0) {
    ALOGE("Failed to get Plane Layouts err=%d", err);
    return {};
  }

  for (uint32_t i = 0; i < layouts.size(); i++) {
    bi.modifiers[i] = bi.modifiers[0];
    bi.pitches[i] = layouts[i].strideInBytes;
    bi.offsets[i] = layouts[i].offsetInBytes;
    bi.sizes[i] = layouts[i].totalSizeInBytes;
  }

  uint64_t usage = 0;
  err = mapper.getUsage(handle, &usage);
  if (err != 0) {
    ALOGE("Failed to get Usage err=%d", err);
    return {};
  }

  if ((usage & GRALLOC_USAGE_CURSOR) != 0) {
    if (layouts.size() > 1) {
      ALOGW("Multiplanar format buffer alignment not supported");
    } else {
      auto aligned = GetAlignedDimensions(layouts[0]);
      if (aligned.has_value()) {
        bi.width = aligned->first;
        bi.height = aligned->second;
      }
    }
  }

  err = GetFds(handle, &bi);
  if (err != 0) {
    ALOGE("Failed to get fds (err=%d)", err);
    return {};
  }

  return bi;
}

}  // namespace android

#endif