diff options
| -rw-r--r-- | include/libcamera/internal/dma_buf_allocator.h | 21 | ||||
| -rw-r--r-- | src/libcamera/dma_buf_allocator.cpp | 74 |
2 files changed, 95 insertions, 0 deletions
diff --git a/include/libcamera/internal/dma_buf_allocator.h b/include/libcamera/internal/dma_buf_allocator.h index 9211d483..fc5de2c1 100644 --- a/include/libcamera/internal/dma_buf_allocator.h +++ b/include/libcamera/internal/dma_buf_allocator.h @@ -12,6 +12,7 @@ #include <vector> #include <libcamera/base/flags.h> +#include <libcamera/base/shared_fd.h> #include <libcamera/base/unique_fd.h> namespace libcamera { @@ -48,6 +49,26 @@ private: 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 */ diff --git a/src/libcamera/dma_buf_allocator.cpp b/src/libcamera/dma_buf_allocator.cpp index 262eb53a..3cc52f96 100644 --- a/src/libcamera/dma_buf_allocator.cpp +++ b/src/libcamera/dma_buf_allocator.cpp @@ -262,4 +262,78 @@ DmaBufAllocator::createBuffer(std::string name, return std::make_unique<FrameBuffer>(planes); } +/** + * \class DmaSyncer + * \brief Helper class for dma-buf's synchronization + * + * This class wraps a userspace dma-buf's synchronization process with an + * object's lifetime. + * + * It's used when the user needs to access a dma-buf with CPU, mostly mapped + * with MappedFrameBuffer, so that the buffer is synchronized between CPU and + * ISP. + */ + +/** + * \enum DmaSyncer::SyncType + * \brief Read and/or write access via the CPU map + * \var DmaSyncer::Read + * \brief Indicates that the mapped dma-buf will be read by the client via the + * CPU map + * \var DmaSyncer::Write + * \brief Indicates that the mapped dm-buf will be written by the client via the + * CPU map + * \var DmaSyncer::ReadWrite + * \brief Indicates that the mapped dma-buf will be read and written by the + * client via the CPU map + */ + +/** + * \brief Construct a DmaSyncer with a dma-buf's fd and the access type + * \param[in] fd The dma-buf's file descriptor to synchronize + * \param[in] type Read and/or write access via the CPU map + */ +DmaSyncer::DmaSyncer(SharedFD fd, SyncType type) + : fd_(fd) +{ + switch (type) { + case SyncType::Read: + flags_ = DMA_BUF_SYNC_READ; + break; + case SyncType::Write: + flags_ = DMA_BUF_SYNC_WRITE; + break; + case SyncType::ReadWrite: + flags_ = DMA_BUF_SYNC_RW; + break; + } + + sync(DMA_BUF_SYNC_START); +} + +DmaSyncer::~DmaSyncer() +{ + sync(DMA_BUF_SYNC_END); +} + +void DmaSyncer::sync(uint64_t step) +{ + struct dma_buf_sync sync = { + .flags = flags_ | step + }; + + int ret; + do { + ret = ioctl(fd_.get(), DMA_BUF_IOCTL_SYNC, &sync); + } while (ret && (errno == EINTR || errno == EAGAIN)); + + if (ret) { + ret = errno; + LOG(DmaBufAllocator, Error) + << "Unable to sync dma fd: " << fd_.get() + << ", err: " << strerror(ret) + << ", flags: " << sync.flags; + } +} + } /* namespace libcamera */ |