path: root/include/linux/hyperv.h

/*
 *
 * Copyright (c) 2011, 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>
 *   K. Y. Srinivasan <kys@microsoft.com>
 *
 */

#ifndef _HYPERV_H
#define _HYPERV_H

#include <uapi/linux/hyperv.h>
#include <uapi/asm/hyperv.h>

#include <linux/types.h>
#include <linux/scatterlist.h>
#include <linux/list.h>
#include <linux/timer.h>
#include <linux/workqueue.h>
#include <linux/completion.h>
#include <linux/device.h>
#include <linux/mod_devicetable.h>


#define MAX_PAGE_BUFFER_COUNT				32
#define MAX_MULTIPAGE_BUFFER_COUNT			32 /* 128K */

#pragma pack(push, 1)

/* Single-page buffer */
struct hv_page_buffer {
	u32 len;
	u32 offset;
	u64 pfn;
};

/* Multiple-page buffer */
struct hv_multipage_buffer {
	/* Length and Offset determines the # of pfns in the array */
	u32 len;
	u32 offset;
	u64 pfn_array[MAX_MULTIPAGE_BUFFER_COUNT];
};

/*
 * Multiple-page buffer array; the pfn array is variable size:
 * The number of entries in the PFN array is determined by
 * "len" and "offset".
 */
struct hv_mpb_array {
	/* Length and Offset determines the # of pfns in the array */
	u32 len;
	u32 offset;
	u64 pfn_array[];
};

/* 0x18 includes the proprietary packet header */
#define MAX_PAGE_BUFFER_PACKET		(0x18 +			\
					(sizeof(struct hv_page_buffer) * \
					 MAX_PAGE_BUFFER_COUNT))
#define MAX_MULTIPAGE_BUFFER_PACKET	(0x18 +			\
					 sizeof(struct hv_multipage_buffer))


#pragma pack(pop)

struct hv_ring_buffer {
	/* Offset in bytes from the start of ring data below */
	u32 write_index;

	/* Offset in bytes from the start of ring data below */
	u32 read_index;

	u32 interrupt_mask;

	/*
	 * Win8 uses some of the reserved bits to implement
	 * interrupt driven flow management. On the send side
	 * we can request that the receiver interrupt the sender
	 * when the ring transitions from being full to being able
	 * to handle a message of size "pending_send_sz".
	 *
	 * Add necessary state for this enhancement.
	 */
	u32 pending_send_sz;

	u32 reserved1[12];

	union {
		struct {
			u32 feat_pending_send_sz:1;
		};
		u32 value;
	} feature_bits;

	/* Pad it to PAGE_SIZE so that data starts on page boundary */
	u8	reserved2[4028];

	/*
	 * Ring data starts here + RingDataStartOffset
	 * !!! DO NOT place any fields below this !!!
	 */
	u8 buffer[0];
} __packed;

struct hv_ring_buffer_info {
	struct hv_ring_buffer *ring_buffer;
	u32 ring_size;			/* Include the shared header */
	spinlock_t ring_lock;

	u32 ring_datasize;		/* < ring_size */
	u32 ring_data_startoffset;
};

/*
 *
 * hv_get_ringbuffer_availbytes()
 *
 * Get number of bytes available to read and to write to
 * for the specified ring buffer
 */
static inline void
hv_get_ringbuffer_availbytes(struct hv_ring_buffer_info *rbi,
			  u32 *read, u32 *write)
{
	u32 read_loc, write_loc, dsize;

	smp_read_barrier_depends();

	/* Capture the read/write indices before they changed */
	read_loc = rbi->ring_buffer->read_index;
	write_loc = rbi->ring_buffer->write_index;
	dsize = rbi->ring_datasize;

	*write = write_loc >= read_loc ? dsize - (write_loc - read_loc) :
		read_loc - write_loc;
	*read = dsize - *write;
}

/*
 * VMBUS version is 32 bit entity broken up into
 * two 16 bit quantities: major_number. minor_number.
 *
 * 0 . 13 (Windows Server 2008)
 * 1 . 1  (Windows 7)
 * 2 . 4  (Windows 8)
 * 3 . 0  (Windows 8 R2)
 * 4 . 0  (Windows 10)
 */

#define VERSION_WS2008  ((0 << 16) | (13))
#define VERSION_WIN7    ((1 << 16) | (1))
#define VERSION_WIN8    ((2 << 16) | (4))
#define VERSION_WIN8_1    ((3 << 16) | (0))
#define VERSION_WIN10	((4 << 16) | (0))

#define VERSION_INVAL -1

#define VERSION_CURRENT VERSION_WIN10

/* Make maximum size of pipe payload of 16K */
#define MAX_PIPE_DATA_PAYLOAD		(sizeof(u8) * 16384)

/* Define PipeMode values. */
#define VMBUS_PIPE_TYPE_BYTE		0x00000000
#define VMBUS_PIPE_TYPE_MESSAGE		0x00000004

/* The size of the user defined data buffer for non-pipe offers. */
#define MAX_USER_DEFINED_BYTES		120

/* The size of the user defined data buffer for pipe offers. */
#define MAX_PIPE_USER_DEFINED_BYTES	116

/*
 * At the center of the Channel Management library is the Channel Offer. This
 * struct contains the fundamental information about an offer.
 */
struct vmbus_channel_offer {
	uuid_le if_type;
	uuid_le if_instance;

	/*
	 * These two fields are not currently used.
	 */
	u64 reserved1;
	u64 reserved2;

	u16 chn_flags;
	u16 mmio_megabytes;		/* in bytes * 1024 * 1024 */

	union {
		/* Non-pipes: The user has MAX_USER_DEFINED_BYTES bytes. */