libcamera: pipeline: raspberrypi: DmaHeaps: Use UniqueFD for a file descriptor

Manages a file descriptor owned by DmaHeaps for a dma handle by
UniqueFD. Furthermore, DmaHeaps::alloc() creates a new file
descriptor and the returned file descriptor is owned by a caller.
This also clarifies it by changing the returned value to UniqueFD.

Signed-off-by: Hirokazu Honda <hiroh@chromium.org>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Hirokazu Honda <hiroh@chromium.org>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>

src/libcamera/pipeline/raspberrypi/dma_heaps.cpp

@@ -35,7 +35,6 @@ LOG_DECLARE_CATEGORY(RPI)
 namespace RPi {
 
 DmaHeap::DmaHeap()
-	: dmaHeapHandle_(-1)
 {
 	for (const char *name : heapNames) {
 		int ret = ::open(name, O_RDWR, 0);
@@ -46,49 +45,44 @@ DmaHeap::DmaHeap()
 			continue;
 		}
 
-		dmaHeapHandle_ = ret;
+		dmaHeapHandle_ = UniqueFD(ret);
 		break;
 	}
 
-	if (dmaHeapHandle_ < 0)
+	if (!dmaHeapHandle_.isValid())
 		LOG(RPI, Error) << "Could not open any dmaHeap device";
 }
 
-DmaHeap::~DmaHeap()
-{
-	if (dmaHeapHandle_ > -1)
-		::close(dmaHeapHandle_);
-}
+DmaHeap::~DmaHeap() = default;
 
-FileDescriptor DmaHeap::alloc(const char *name, std::size_t size)
+UniqueFD DmaHeap::alloc(const char *name, std::size_t size)
 {
 	int ret;
 
 	if (!name)
-		return FileDescriptor();
+		return {};
 
 	struct dma_heap_allocation_data alloc = {};
 
 	alloc.len = size;
 	alloc.fd_flags = O_CLOEXEC | O_RDWR;
 
-	ret = ::ioctl(dmaHeapHandle_, DMA_HEAP_IOCTL_ALLOC, &alloc);
-
+	ret = ::ioctl(dmaHeapHandle_.get(), DMA_HEAP_IOCTL_ALLOC, &alloc);
 	if (ret < 0) {
 		LOG(RPI, Error) << "dmaHeap allocation failure for "
 				<< name;
-		return FileDescriptor();
+		return {};
 	}
 
-	ret = ::ioctl(alloc.fd, DMA_BUF_SET_NAME, name);
+	UniqueFD allocFd(alloc.fd);
+	ret = ::ioctl(allocFd.get(), DMA_BUF_SET_NAME, name);
 	if (ret < 0) {
 		LOG(RPI, Error) << "dmaHeap naming failure for "
 				<< name;
-		::close(alloc.fd);
-		return FileDescriptor();
+		return {};
 	}
 
-	return FileDescriptor(std::move(alloc.fd));
+	return allocFd;
 }
 
 } /* namespace RPi */

src/libcamera/pipeline/raspberrypi/dma_heaps.h

@@ -7,7 +7,9 @@
 
 #pragma once
 
-#include <libcamera/base/file_descriptor.h>
+#include <stddef.h>
+
+#include <libcamera/base/unique_fd.h>
 
 namespace libcamera {
 
@@ -18,11 +20,11 @@ class DmaHeap
 public:
 	DmaHeap();
 	~DmaHeap();
-	bool isValid() const { return dmaHeapHandle_ > -1; }
-	FileDescriptor alloc(const char *name, std::size_t size);
+	bool isValid() const { return dmaHeapHandle_.isValid(); }
+	UniqueFD alloc(const char *name, std::size_t size);
 
 private:
-	int dmaHeapHandle_;
+	UniqueFD dmaHeapHandle_;
 };
 
 } /* namespace RPi */

src/libcamera/pipeline/raspberrypi/raspberrypi.cpp

@@ -1393,7 +1393,7 @@ int RPiCameraData::configureIPA(const CameraConfiguration *config)
 
 	/* Allocate the lens shading table via dmaHeap and pass to the IPA. */
 	if (!lsTable_.isValid()) {
-		lsTable_ = dmaHeap_.alloc("ls_grid", ipa::RPi::MaxLsGridSize);
+		lsTable_ = FileDescriptor(dmaHeap_.alloc("ls_grid", ipa::RPi::MaxLsGridSize));
 		if (!lsTable_.isValid())
 			return -ENOMEM;