1 files changed, 101 insertions, 0 deletions
diff --git a/drivers/staging/hv/ring_buffer.h b/drivers/staging/hv/ring_buffer.h
new file mode 100644
index 000000000000..6202157e145d
--- /dev/null
+++ b/drivers/staging/hv/ring_buffer.h
@@ -0,0 +1,101 @@
+/*
+ *
+ * Copyright (c) 2009, Microsoft Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
+ * Place - Suite 330, Boston, MA 02111-1307 USA.
+ *
+ * Authors:
+ *   Haiyang Zhang <haiyangz@microsoft.com>
+ *   Hank Janssen  <hjanssen@microsoft.com>
+ *
+ */
+
+
+#ifndef _RING_BUFFER_H_
+#define _RING_BUFFER_H_
+
+#include <linux/scatterlist.h>
+
+typedef struct _RING_BUFFER {
+	/* Offset in bytes from the start of ring data below */
+	volatile u32 WriteIndex;
+
+	/* Offset in bytes from the start of ring data below */
+	volatile u32 ReadIndex;
+
+	volatile u32 InterruptMask;
+
+	/* Pad it to PAGE_SIZE so that data starts on page boundary */
+	u8	Reserved[4084];
+
+	/* NOTE:
+	 * The InterruptMask field is used only for channels but since our
+	 * vmbus connection also uses this data structure and its data starts
+	 * here, we commented out this field.
+	 */
+	/* volatile u32 InterruptMask; */
+
+	/*
+	 * Ring data starts here + RingDataStartOffset
+	 * !!! DO NOT place any fields below this !!!
+	 */
+	u8 Buffer[0];
+} __attribute__((packed)) RING_BUFFER;
+
+typedef struct _RING_BUFFER_INFO {
+	RING_BUFFER *RingBuffer;
+	u32 RingSize;			/* Include the shared header */
+	spinlock_t ring_lock;
+
+	u32 RingDataSize;		/* < ringSize */
+	u32 RingDataStartOffset;
+
+} RING_BUFFER_INFO;
+
+typedef struct _RING_BUFFER_DEBUG_INFO {
+	u32 CurrentInterruptMask;
+	u32 CurrentReadIndex;
+	u32 CurrentWriteIndex;
+	u32 BytesAvailToRead;
+	u32 BytesAvailToWrite;
+} RING_BUFFER_DEBUG_INFO;
+
+
+
+/* Interface */
+
+
+int RingBufferInit(RING_BUFFER_INFO *RingInfo, void *Buffer, u32 BufferLen);
+
+void RingBufferCleanup(RING_BUFFER_INFO *RingInfo);
+
+int RingBufferWrite(RING_BUFFER_INFO *RingInfo,
+		    struct scatterlist *sglist,
+		    u32 sgcount);
+
+int RingBufferPeek(RING_BUFFER_INFO *RingInfo, void *Buffer, u32 BufferLen);
+
+int RingBufferRead(RING_BUFFER_INFO *RingInfo,
+		   void *Buffer,
+		   u32 BufferLen,
+		   u32 Offset);
+
+u32 GetRingBufferInterruptMask(RING_BUFFER_INFO *RingInfo);
+
+void DumpRingInfo(RING_BUFFER_INFO *RingInfo, char *Prefix);
+
+void RingBufferGetDebugInfo(RING_BUFFER_INFO *RingInfo,
+			    RING_BUFFER_DEBUG_INFO *DebugInfo);
+
+#endif /* _RING_BUFFER_H_ */