From 87ee158ec8896fdb0bec186be36f9a7ace54aca0 Mon Sep 17 00:00:00 2001 From: Andrey Konovalov Date: Tue, 16 Apr 2024 11:13:39 +0200 Subject: libcamera: dma_heaps: extend DmaHeap class to support system heap Add an argument to the constructor to specify dma heaps type(s) to use. Can be DmaHeapFlag::Cma and/or DmaHeapFlag::System. By default DmaHeapFlag::Cma is used. If both DmaHeapFlag::Cma and DmaHeapFlag::System are set, CMA heap is tried first. Tested-by: Bryan O'Donoghue # sc8280xp Lenovo x13s Tested-by: Pavel Machek Reviewed-by: Milan Zamazal Reviewed-by: Pavel Machek Reviewed-by: Laurent Pinchart Signed-off-by: Andrey Konovalov Signed-off-by: Hans de Goede Signed-off-by: Kieran Bingham --- src/libcamera/dma_heaps.cpp | 69 ++++++++++++++++++++++++++++++++++++--------- 1 file changed, 55 insertions(+), 14 deletions(-) (limited to 'src') diff --git a/src/libcamera/dma_heaps.cpp b/src/libcamera/dma_heaps.cpp index e543045d..b4509e72 100644 --- a/src/libcamera/dma_heaps.cpp +++ b/src/libcamera/dma_heaps.cpp @@ -19,9 +19,11 @@ /** * \file dma_heaps.cpp - * \brief CMA dma-heap allocator + * \brief dma-heap allocator */ +namespace libcamera { + /* * /dev/dma_heap/linux,cma is the dma-heap allocator, which allows dmaheap-cma * to only have to worry about importing. @@ -29,40 +31,79 @@ * Annoyingly, should the cma heap size be specified on the kernel command line * instead of DT, the heap gets named "reserved" instead. */ -static constexpr std::array heapNames = { - "/dev/dma_heap/linux,cma", - "/dev/dma_heap/reserved" + +#ifndef __DOXYGEN__ +struct DmaHeapInfo { + DmaHeap::DmaHeapFlag type; + const char *deviceNodeName; }; +#endif -namespace libcamera { +static constexpr std::array heapInfos = { { + { DmaHeap::DmaHeapFlag::Cma, "/dev/dma_heap/linux,cma" }, + { DmaHeap::DmaHeapFlag::Cma, "/dev/dma_heap/reserved" }, + { DmaHeap::DmaHeapFlag::System, "/dev/dma_heap/system" }, +} }; LOG_DEFINE_CATEGORY(DmaHeap) /** * \class DmaHeap - * \brief Helper class for CMA dma-heap allocations + * \brief Helper class for dma-heap allocations + * + * DMA heaps are kernel devices that provide an API to allocate memory from + * different pools called "heaps", wrap each allocated piece of memory in a + * dmabuf object, and return the dmabuf file descriptor to userspace. Multiple + * heaps can be provided by the system, with different properties for the + * underlying memory. + * + * This class wraps a DMA heap selected at construction time, and exposes + * functions to manage memory allocation. + */ + +/** + * \enum DmaHeap::DmaHeapFlag + * \brief Type of the dma-heap + * \var DmaHeap::Cma + * \brief Allocate from a CMA dma-heap, providing physically-contiguous memory + * \var DmaHeap::System + * \brief Allocate from the system dma-heap, using the page allocator */ /** - * \brief Construct a DmaHeap that owns a CMA dma-heap file descriptor + * \typedef DmaHeap::DmaHeapFlags + * \brief A bitwise combination of DmaHeap::DmaHeapFlag values + */ + +/** + * \brief Construct a DmaHeap of a given type + * \param[in] type The type(s) of the dma-heap(s) to allocate from * - * Looks for a CMA dma-heap device to use. If it fails to open any dma-heap - * device, an invalid DmaHeap object is constructed. + * The DMA heap type is selected with the \a type parameter, which defaults to + * the CMA heap. If no heap of the given type can be accessed, the constructed + * DmaHeap instance is invalid as indicated by the isValid() function. * - * Check the new DmaHeap object with isValid before using it. + * Multiple types can be selected by combining type flags, in which case the + * constructed DmaHeap will match one of the types. If the system provides + * multiple heaps that match the requested types, which heap is used is + * undefined. */ -DmaHeap::DmaHeap() +DmaHeap::DmaHeap(DmaHeapFlags type) { - for (const char *name : heapNames) { - int ret = ::open(name, O_RDWR | O_CLOEXEC, 0); + for (const auto &info : heapInfos) { + if (!(type & info.type)) + continue; + + int ret = ::open(info.deviceNodeName, O_RDWR | O_CLOEXEC, 0); if (ret < 0) { ret = errno; LOG(DmaHeap, Debug) - << "Failed to open " << name << ": " + << "Failed to open " << info.deviceNodeName << ": " << strerror(ret); continue; } + LOG(DmaHeap, Debug) << "Using " << info.deviceNodeName; dmaHeapHandle_ = UniqueFD(ret); break; } -- cgit v1.2.1