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/*
*
* 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>
#include "include/osd.h"
typedef struct _RING_BUFFER {
volatile u32 WriteIndex; /* Offset in bytes from the start of ring data below */
volatile u32 ReadIndex; /* Offset in bytes from the start of ring data below */
volatile u32 InterruptMask;
u8 Reserved[4084]; /* Pad it to PAGE_SIZE so that data starts on page boundary */
/* 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 */
static int
RingBufferInit(
RING_BUFFER_INFO *RingInfo,
void * Buffer,
u32 BufferLen
);
static void
RingBufferCleanup(
RING_BUFFER_INFO *RingInfo
);
static int
RingBufferWrite(
RING_BUFFER_INFO *RingInfo,
struct scatterlist *sglist,
u32 sgcount
);
static int
RingBufferPeek(
RING_BUFFER_INFO *RingInfo,
void * Buffer,
u32 BufferLen
);
static int
RingBufferRead(
RING_BUFFER_INFO *RingInfo,
void * Buffer,
u32 BufferLen,
u32 Offset
);
static u32
GetRingBufferInterruptMask(
RING_BUFFER_INFO *RingInfo
);
static void
DumpRingInfo(
RING_BUFFER_INFO* RingInfo,
char *Prefix
);
static void
RingBufferGetDebugInfo(
RING_BUFFER_INFO *RingInfo,
RING_BUFFER_DEBUG_INFO *DebugInfo
);
#endif /* _RING_BUFFER_H_ */
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