Current File : //usr/src/kernels/3.10.0-1160.81.1.el7.centos.plus.x86_64/include/xen/gntdev.h
/******************************************************************************
* gntdev.h
*
* Interface to /dev/xen/gntdev.
*
* Copyright (c) 2007, D G Murray
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License version 2
* as published by the Free Software Foundation; or, when distributed
* separately from the Linux kernel or incorporated into other
* software packages, subject to the following license:
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this source file (the "Software"), to deal in the Software without
* restriction, including without limitation the rights to use, copy, modify,
* merge, publish, distribute, sublicense, and/or sell copies of the Software,
* and to permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
* IN THE SOFTWARE.
*/
#ifndef __LINUX_PUBLIC_GNTDEV_H__
#define __LINUX_PUBLIC_GNTDEV_H__
struct ioctl_gntdev_grant_ref {
/* The domain ID of the grant to be mapped. */
uint32_t domid;
/* The grant reference of the grant to be mapped. */
uint32_t ref;
};
/*
* Inserts the grant references into the mapping table of an instance
* of gntdev. N.B. This does not perform the mapping, which is deferred
* until mmap() is called with @index as the offset.
*/
#define IOCTL_GNTDEV_MAP_GRANT_REF \
_IOC(_IOC_NONE, 'G', 0, sizeof(struct ioctl_gntdev_map_grant_ref))
struct ioctl_gntdev_map_grant_ref {
/* IN parameters */
/* The number of grants to be mapped. */
uint32_t count;
uint32_t pad;
/* OUT parameters */
/* The offset to be used on a subsequent call to mmap(). */
uint64_t index;
/* Variable IN parameter. */
/* Array of grant references, of size @count. */
struct ioctl_gntdev_grant_ref refs[1];
};
/*
* Removes the grant references from the mapping table of an instance of
* of gntdev. N.B. munmap() must be called on the relevant virtual address(es)
* before this ioctl is called, or an error will result.
*/
#define IOCTL_GNTDEV_UNMAP_GRANT_REF \
_IOC(_IOC_NONE, 'G', 1, sizeof(struct ioctl_gntdev_unmap_grant_ref))
struct ioctl_gntdev_unmap_grant_ref {
/* IN parameters */
/* The offset was returned by the corresponding map operation. */
uint64_t index;
/* The number of pages to be unmapped. */
uint32_t count;
uint32_t pad;
};
/*
* Returns the offset in the driver's address space that corresponds
* to @vaddr. This can be used to perform a munmap(), followed by an
* UNMAP_GRANT_REF ioctl, where no state about the offset is retained by
* the caller. The number of pages that were allocated at the same time as
* @vaddr is returned in @count.
*
* N.B. Where more than one page has been mapped into a contiguous range, the
* supplied @vaddr must correspond to the start of the range; otherwise
* an error will result. It is only possible to munmap() the entire
* contiguously-allocated range at once, and not any subrange thereof.
*/
#define IOCTL_GNTDEV_GET_OFFSET_FOR_VADDR \
_IOC(_IOC_NONE, 'G', 2, sizeof(struct ioctl_gntdev_get_offset_for_vaddr))
struct ioctl_gntdev_get_offset_for_vaddr {
/* IN parameters */
/* The virtual address of the first mapped page in a range. */
uint64_t vaddr;
/* OUT parameters */
/* The offset that was used in the initial mmap() operation. */
uint64_t offset;
/* The number of pages mapped in the VM area that begins at @vaddr. */
uint32_t count;
uint32_t pad;
};
/*
* Sets the maximum number of grants that may mapped at once by this gntdev
* instance.
*
* N.B. This must be called before any other ioctl is performed on the device.
*/
#define IOCTL_GNTDEV_SET_MAX_GRANTS \
_IOC(_IOC_NONE, 'G', 3, sizeof(struct ioctl_gntdev_set_max_grants))
struct ioctl_gntdev_set_max_grants {
/* IN parameter */
/* The maximum number of grants that may be mapped at once. */
uint32_t count;
};
/*
* Sets up an unmap notification within the page, so that the other side can do
* cleanup if this side crashes. Required to implement cross-domain robust
* mutexes or close notification on communication channels.
*
* Each mapped page only supports one notification; multiple calls referring to
* the same page overwrite the previous notification. You must clear the
* notification prior to the IOCTL_GNTALLOC_DEALLOC_GREF if you do not want it
* to occur.
*/
#define IOCTL_GNTDEV_SET_UNMAP_NOTIFY \
_IOC(_IOC_NONE, 'G', 7, sizeof(struct ioctl_gntdev_unmap_notify))
struct ioctl_gntdev_unmap_notify {
/* IN parameters */
/* Offset in the file descriptor for a byte within the page (same as
* used in mmap). If using UNMAP_NOTIFY_CLEAR_BYTE, this is the byte to
* be cleared. Otherwise, it can be any byte in the page whose
* notification we are adjusting.
*/
uint64_t index;
/* Action(s) to take on unmap */
uint32_t action;
/* Event channel to notify */
uint32_t event_channel_port;
};
/* Clear (set to zero) the byte specified by index */
#define UNMAP_NOTIFY_CLEAR_BYTE 0x1
/* Send an interrupt on the indicated event channel */
#define UNMAP_NOTIFY_SEND_EVENT 0x2
#endif /* __LINUX_PUBLIC_GNTDEV_H__ */
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