[deliverable/linux.git] / drivers / staging / hv / ring_buffer.h

/*
 *
 * 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>

struct hv_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));

struct hv_ring_buffer_info {
	struct hv_ring_buffer *RingBuffer;
	u32 RingSize;			/* Include the shared header */
	spinlock_t ring_lock;

	u32 RingDataSize;		/* < ringSize */
	u32 RingDataStartOffset;
};

struct hv_ring_buffer_debug_info {
	u32 CurrentInterruptMask;
	u32 CurrentReadIndex;
	u32 CurrentWriteIndex;
	u32 BytesAvailToRead;
	u32 BytesAvailToWrite;
};


/* Interface */


int RingBufferInit(struct hv_ring_buffer_info *RingInfo, void *Buffer,
		   u32 BufferLen);

void RingBufferCleanup(struct hv_ring_buffer_info *RingInfo);

int RingBufferWrite(struct hv_ring_buffer_info *RingInfo,
		    struct scatterlist *sglist,
		    u32 sgcount);

int RingBufferPeek(struct hv_ring_buffer_info *RingInfo, void *Buffer,
		   u32 BufferLen);

int RingBufferRead(struct hv_ring_buffer_info *RingInfo,
		   void *Buffer,
		   u32 BufferLen,
		   u32 Offset);

u32 GetRingBufferInterruptMask(struct hv_ring_buffer_info *RingInfo);

void DumpRingInfo(struct hv_ring_buffer_info *RingInfo, char *Prefix);

void RingBufferGetDebugInfo(struct hv_ring_buffer_info *RingInfo,
			    struct hv_ring_buffer_debug_info *debug_info);

#endif /* _RING_BUFFER_H_ */
Commit	Line	Data
3e7ee490 HJ	1	/*
	2	*
	3	* Copyright (c) 2009, Microsoft Corporation.
	4	*
	5	* This program is free software; you can redistribute it and/or modify it
	6	* under the terms and conditions of the GNU General Public License,
	7	* version 2, as published by the Free Software Foundation.
	8	*
	9	* This program is distributed in the hope it will be useful, but WITHOUT
	10	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	11	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
	12	* more details.
	13	*
	14	* You should have received a copy of the GNU General Public License along with
	15	* this program; if not, write to the Free Software Foundation, Inc., 59 Temple
	16	* Place - Suite 330, Boston, MA 02111-1307 USA.
	17	*
	18	* Authors:
	19	* Haiyang Zhang <haiyangz@microsoft.com>
	20	* Hank Janssen <hjanssen@microsoft.com>
	21	*
	22	*/
	23
	24
	25	#ifndef _RING_BUFFER_H_
	26	#define _RING_BUFFER_H_
	27
b219b3f7	28	#include <linux/scatterlist.h>
3e7ee490	29
4a1b3acc	30	struct hv_ring_buffer {
3523a805 GKH	31	/* Offset in bytes from the start of ring data below */
	32	volatile u32 WriteIndex;
	33
	34	/* Offset in bytes from the start of ring data below */
	35	volatile u32 ReadIndex;
3e7ee490	36
4d643114	37	volatile u32 InterruptMask;
3523a805 GKH	38
	39	/* Pad it to PAGE_SIZE so that data starts on page boundary */
	40	u8 Reserved[4084];
	41
	42	/* NOTE:
	43	* The InterruptMask field is used only for channels but since our
	44	* vmbus connection also uses this data structure and its data starts
	45	* here, we commented out this field.
	46	*/
454f18a9	47	/* volatile u32 InterruptMask; */
3523a805 GKH	48
	49	/*
	50	* Ring data starts here + RingDataStartOffset
	51	* !!! DO NOT place any fields below this !!!
	52	*/
	53	u8 Buffer[0];
4a1b3acc	54	} __attribute__((packed));
3e7ee490	55
8a0e1c55	56	struct hv_ring_buffer_info {
4a1b3acc	57	struct hv_ring_buffer *RingBuffer;
3523a805	58	u32 RingSize; /* Include the shared header */
a98f96ee	59	spinlock_t ring_lock;
3e7ee490	60
3523a805 GKH	61	u32 RingDataSize; /* < ringSize */
3523a805 GKH	62	u32 RingDataStartOffset;
8a0e1c55	63	};
3e7ee490	64
80682b7a	65	struct hv_ring_buffer_debug_info {
3523a805 GKH	66	u32 CurrentInterruptMask;
	67	u32 CurrentReadIndex;
	68	u32 CurrentWriteIndex;
	69	u32 BytesAvailToRead;
	70	u32 BytesAvailToWrite;
80682b7a	71	};
3e7ee490 HJ	72
3e7ee490 HJ	73
454f18a9 BP	74
	75	/* Interface */
	76
3e7ee490	77
8a0e1c55 GKH	78	int RingBufferInit(struct hv_ring_buffer_info RingInfo, void Buffer,
8a0e1c55 GKH	79	u32 BufferLen);
3523a805	80
8a0e1c55	81	void RingBufferCleanup(struct hv_ring_buffer_info *RingInfo);
3523a805	82
8a0e1c55	83	int RingBufferWrite(struct hv_ring_buffer_info *RingInfo,
3523a805 GKH	84	struct scatterlist *sglist,
	85	u32 sgcount);
	86
8a0e1c55 GKH	87	int RingBufferPeek(struct hv_ring_buffer_info RingInfo, void Buffer,
8a0e1c55 GKH	88	u32 BufferLen);
3523a805	89
8a0e1c55	90	int RingBufferRead(struct hv_ring_buffer_info *RingInfo,
3523a805 GKH	91	void *Buffer,
	92	u32 BufferLen,
	93	u32 Offset);
	94
8a0e1c55	95	u32 GetRingBufferInterruptMask(struct hv_ring_buffer_info *RingInfo);
3523a805	96
8a0e1c55	97	void DumpRingInfo(struct hv_ring_buffer_info RingInfo, char Prefix);
3523a805	98
8a0e1c55	99	void RingBufferGetDebugInfo(struct hv_ring_buffer_info *RingInfo,
80682b7a	100	struct hv_ring_buffer_debug_info *debug_info);
3e7ee490	101
454f18a9	102	#endif /* _RING_BUFFER_H_ */