File write buffers moved to non-cached memory for SAME70

3 files changed, 29 insertions, 15 deletions

diff --git a/src/Storage/FileStore.cpp b/src/Storage/FileStore.cpp
index 516065cf..57d335e7 100644
--- a/src/Storage/FileStore.cpp
+++ b/src/Storage/FileStore.cpp
@@ -93,7 +93,7 @@ bool FileStore::Open(const char* filePath, OpenMode mode, uint32_t preAllocSize)
 			// Also try to allocate a write buffer so we can perform faster writes
 			// We only do this if the mode is write, not append, because we don't want to use up a large buffer to append messages to the log file,
 			// especially as we need to flush messages to SD card regularly.
-			// Currently, append mode is used for the log file and for appending simulated print times to GCodes files (which required read access too).
+			// Currently, append mode is used for the log file and for appending simulated print times to GCodes files (which require read access too).
 			if (mode == OpenMode::write || mode == OpenMode::writeWithCrc)
 			{
 				writeBuffer = MassStorage::AllocateWriteBuffer();
@@ -497,7 +497,7 @@ bool FileStore::Write(const char *s, size_t len) noexcept
 			{
 				do
 				{
-					size_t bytesStored = writeBuffer->Store(s + totalBytesWritten, len - totalBytesWritten);
+					const size_t bytesStored = writeBuffer->Store(s + totalBytesWritten, len - totalBytesWritten);
 					if (writeBuffer->BytesLeft() == 0)
 					{
 						const size_t bytesToWrite = writeBuffer->BytesStored();
diff --git a/src/Storage/FileWriteBuffer.h b/src/Storage/FileWriteBuffer.h
index bd3804db..0708f042 100644
--- a/src/Storage/FileWriteBuffer.h
+++ b/src/Storage/FileWriteBuffer.h
@@ -32,13 +32,17 @@ const size_t FileWriteBufLen = 4096;
 class FileWriteBuffer
 {
 public:
+#if SAME70
+	FileWriteBuffer(FileWriteBuffer *n, char *storage) noexcept : next(n), index(0), buf(storage) { }
+#else
 	FileWriteBuffer(FileWriteBuffer *n) noexcept : next(n), index(0) { }
+#endif
 
 	FileWriteBuffer *Next() const noexcept { return next; }
 	void SetNext(FileWriteBuffer *n) noexcept { next = n; }
 
-	char *Data() noexcept { return reinterpret_cast<char *>(data32); }
-	const char *Data() const noexcept { return reinterpret_cast<const char *>(data32); }
+	char *Data() noexcept { return buf; }
+	const char *Data() const noexcept { return buf; }
 	const size_t BytesStored() const noexcept { return index; }
 	const size_t BytesLeft() const noexcept { return FileWriteBufLen - index; }
 
@@ -50,13 +54,17 @@ private:
 	FileWriteBuffer *next;
 
 	size_t index;
-	uint32_t data32[FileWriteBufLen / sizeof(uint32_t)];	// 32-bit aligned buffer for better HSMCI performance
+#if SAME70
+	char *buf;
+#else
+	alignas(4) char buf[FileWriteBufLen];								// 32-bit aligned buffer for better HSMCI performance
+#endif
 };
 
 inline size_t FileWriteBuffer::Store(const char *data, size_t length) noexcept
 {
 	size_t bytesToStore = min<size_t>(BytesLeft(), length);
-	memcpy(Data() + index, data, bytesToStore);
+	memcpy(buf + index, data, bytesToStore);
 	index += bytesToStore;
 	return bytesToStore;
 }
diff --git a/src/Storage/MassStorage.cpp b/src/Storage/MassStorage.cpp
index dbfe0cf2..dbb8c7db 100644
--- a/src/Storage/MassStorage.cpp
+++ b/src/Storage/MassStorage.cpp
@@ -29,9 +29,10 @@ static_assert(SD_MMC_MEM_CNT == NumSdCards);
 
 // Private data and methods
 
-#if SAME70
-alignas(4) static __nocache uint8_t sectorBuffers[512][NumSdCards];
-#endif
+# if SAME70
+alignas(4) static __nocache uint8_t sectorBuffers[NumSdCards][512];
+alignas(4) static __nocache char writeBufferStorage[NumFileWriteBuffers][FileWriteBufLen];
+# endif
 
 enum class CardDetectState : uint8_t
 {
@@ -121,6 +122,7 @@ static FileInfoParser infoParser;
 static DIR findDir;
 static FileWriteBuffer *freeWriteBuffers;
 #endif
+
 #if HAS_MASS_STORAGE || HAS_LINUX_INTERFACE
 static Mutex fsMutex;
 static FileStore files[MAX_FILES];
@@ -167,14 +169,14 @@ static FileStore files[MAX_FILES];
 FileWriteBuffer *MassStorage::AllocateWriteBuffer() noexcept
 {
 	MutexLocker lock(fsMutex);
-	if (freeWriteBuffers == nullptr)
-	{
-		return nullptr;
-	}
 
 	FileWriteBuffer * const buffer = freeWriteBuffers;
-	freeWriteBuffers = buffer->Next();
-	buffer->SetNext(nullptr);
+	if (buffer != nullptr)
+	{
+		freeWriteBuffers = buffer->Next();
+		buffer->SetNext(nullptr);
+		buffer->DataTaken();				// make sure that the write pointer is clear
+	}
 	return buffer;
 }
 
@@ -271,7 +273,11 @@ void MassStorage::Init() noexcept
 	freeWriteBuffers = nullptr;
 	for (size_t i = 0; i < NumFileWriteBuffers; ++i)
 	{
+#if SAME70
+		freeWriteBuffers = new FileWriteBuffer(freeWriteBuffers, writeBufferStorage[i]);
+#else
 		freeWriteBuffers = new FileWriteBuffer(freeWriteBuffers);
+#endif
 	}
 
 	for (size_t card = 0; card < NumSdCards; ++card)