dma_buf_allocator.h

/* SPDX-License-Identifier: LGPL-2.1-or-later */
/*
 * Copyright (C) 2020, Raspberry Pi Ltd
 *
 * Helper class for dma-buf allocations.
 */

#pragma once

#include <memory>
#include <string>
#include <vector>

#include <libcamera/base/flags.h>
#include <libcamera/base/shared_fd.h>
#include <libcamera/base/unique_fd.h>

namespace libcamera {

class FrameBuffer;

class DmaBufAllocator
{
public:
    enum class DmaBufAllocatorFlag {
        CmaHeap = 1 << 0,
        SystemHeap = 1 << 1,
        UDmaBuf = 1 << 2,
    };

    using DmaBufAllocatorFlags = Flags<DmaBufAllocatorFlag>;

    DmaBufAllocator(DmaBufAllocatorFlags flags = DmaBufAllocatorFlag::CmaHeap);
    ~DmaBufAllocator();
    bool isValid() const { return providerHandle_.isValid(); }
    UniqueFD alloc(const char *name, std::size_t size);

    int exportBuffers(unsigned int count,
              const std::vector<unsigned int> &planeSizes,
              std::vector<std::unique_ptr<FrameBuffer>> *buffers);

private:
    std::unique_ptr<FrameBuffer> createBuffer(
        std::string name, const std::vector<unsigned int> &planeSizes);

    UniqueFD allocFromHeap(const char *name, std::size_t size);
    UniqueFD allocFromUDmaBuf(const char *name, std::size_t size);
    UniqueFD providerHandle_;
    DmaBufAllocatorFlag type_;
};

class DmaSyncer final
{
public:
    enum class SyncType {
        Read = 0,
        Write,
        ReadWrite,
    };

    explicit DmaSyncer(SharedFD fd, SyncType type = SyncType::ReadWrite);

    ~DmaSyncer();

private:
    void sync(uint64_t step);

    SharedFD fd_;
    uint64_t flags_ = 0;
};

LIBCAMERA_FLAGS_ENABLE_OPERATORS(DmaBufAllocator::DmaBufAllocatorFlag)

} /* namespace libcamera */