[libcamera-devel] [PATCH v2 03/18] libcamera: dma_heaps: extend DmaHeap class to support system heap

[Hans de Goede]

From: Andrey Konovalov <andrey.konovalov at linaro.org>

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.

Signed-off-by: Andrey Konovalov <andrey.konovalov at linaro.org>
Signed-off-by: Hans de Goede <hdegoede at redhat.com>
Tested-by: Bryan O'Donoghue <bryan.odonoghue at linaro.org> # sc8280xp Lenovo x13s
Tested-by: Pavel Machek <pavel at ucw.cz>
---
 include/libcamera/internal/dma_heaps.h | 12 +++++++-
 src/libcamera/dma_heaps.cpp            | 39 +++++++++++++++-----------
 2 files changed, 34 insertions(+), 17 deletions(-)

diff --git a/include/libcamera/internal/dma_heaps.h b/include/libcamera/internal/dma_heaps.h
index cff8f140..22aa1007 100644
--- a/include/libcamera/internal/dma_heaps.h
+++ b/include/libcamera/internal/dma_heaps.h
@@ -9,6 +9,7 @@
 
 #include <stddef.h>
 
+#include <libcamera/base/flags.h>
 #include <libcamera/base/unique_fd.h>
 
 namespace libcamera {
@@ -16,7 +17,14 @@ namespace libcamera {
 class DmaHeap
 {
 public:
-	DmaHeap();
+	enum class DmaHeapFlag {
+		Cma = (1 << 0),
+		System = (1 << 1),
+	};
+
+	using DmaHeapFlags = Flags<DmaHeapFlag>;
+
+	DmaHeap(DmaHeapFlags flags = DmaHeapFlag::Cma);
 	~DmaHeap();
 	bool isValid() const { return dmaHeapHandle_.isValid(); }
 	UniqueFD alloc(const char *name, std::size_t size);
@@ -25,4 +33,6 @@ private:
 	UniqueFD dmaHeapHandle_;
 };
 
+LIBCAMERA_FLAGS_ENABLE_OPERATORS(DmaHeap::DmaHeapFlag)
+
 } /* namespace libcamera */
diff --git a/src/libcamera/dma_heaps.cpp b/src/libcamera/dma_heaps.cpp
index 7444d9c2..177de31b 100644
--- a/src/libcamera/dma_heaps.cpp
+++ b/src/libcamera/dma_heaps.cpp
@@ -16,6 +16,8 @@
 
 #include "libcamera/internal/dma_heaps.h"
 
+namespace libcamera {
+
 /*
  * /dev/dma-heap/linux,cma is the dma-heap allocator, which allows dmaheap-cma
  * to only have to worry about importing.
@@ -23,28 +25,33 @@
  * 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<const char *, 2> heapNames = {
-	"/dev/dma_heap/linux,cma",
-	"/dev/dma_heap/reserved"
+static constexpr std::array<std::pair<DmaHeap::DmaHeapFlag, const char *>, 3> heapNames = {
+	/* CMA heap names first */
+	std::make_pair(DmaHeap::DmaHeapFlag::Cma, "/dev/dma_heap/linux,cma"),
+	std::make_pair(DmaHeap::DmaHeapFlag::Cma, "/dev/dma_heap/reserved"),
+	std::make_pair(DmaHeap::DmaHeapFlag::System, "/dev/dma_heap/system")
 };
 
-namespace libcamera {
-
 LOG_DEFINE_CATEGORY(DmaHeap)
 
-DmaHeap::DmaHeap()
+DmaHeap::DmaHeap(DmaHeapFlags flags)
 {
-	for (const char *name : heapNames) {
-		int ret = ::open(name, O_RDWR | O_CLOEXEC, 0);
-		if (ret < 0) {
-			ret = errno;
-			LOG(DmaHeap, Debug) << "Failed to open " << name << ": "
-					<< strerror(ret);
-			continue;
-		}
+	int ret;
 
-		dmaHeapHandle_ = UniqueFD(ret);
-		break;
+	for (const auto &name : heapNames) {
+		if (flags & name.first) {
+			ret = ::open(name.second, O_RDWR | O_CLOEXEC, 0);
+			if (ret < 0) {
+				ret = errno;
+				LOG(DmaHeap, Debug) << "Failed to open " << name.second << ": "
+						    << strerror(ret);
+				continue;
+			}
+
+			LOG(DmaHeap, Debug) << "Using " << name.second;
+			dmaHeapHandle_ = UniqueFD(ret);
+			break;
+		}
 	}
 
 	if (!dmaHeapHandle_.isValid())
-- 
2.43.0