code.delx.au - pulseaudio/blob - src/modules/xen/gntdev.h

   1 /*
   2  * This file is copied from the linux kernel headers. It defines the standard
   3  * interface to the xen/gntdev device.
   4  *
   5  */
   6
   7 /******************************************************************************
   8  * gntdev.h
   9  *
  10  * Interface to /dev/xen/gntdev.
  11  *
  12  * Copyright (c) 2007, D G Murray
  13  *
  14  * This program is free software; you can redistribute it and/or
  15  * modify it under the terms of the GNU General Public License version 2
  16  * as published by the Free Software Foundation; or, when distributed
  17  * separately from the Linux kernel or incorporated into other
  18  * software packages, subject to the following license:
  19  *
  20  * Permission is hereby granted, free of charge, to any person obtaining a copy
  21  * of this source file (the "Software"), to deal in the Software without
  22  * restriction, including without limitation the rights to use, copy, modify,
  23  * merge, publish, distribute, sublicense, and/or sell copies of the Software,
  24  * and to permit persons to whom the Software is furnished to do so, subject to
  25  * the following conditions:
  26  *
  27  * The above copyright notice and this permission notice shall be included in
  28  * all copies or substantial portions of the Software.
  29  *
  30  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  31  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  32  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  33  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  34  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  35  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
  36  * IN THE SOFTWARE.
  37  */
  38
  39 #ifndef __LINUX_PUBLIC_GNTDEV_H__
  40 #define __LINUX_PUBLIC_GNTDEV_H__
  41
  42 struct ioctl_gntdev_grant_ref {
  43         /* The domain ID of the grant to be mapped. */
  44         uint32_t domid;
  45         /* The grant reference of the grant to be mapped. */
  46         uint32_t ref;
  47 };
  48
  49 /*
  50  * Inserts the grant references into the mapping table of an instance
  51  * of gntdev. N.B. This does not perform the mapping, which is deferred
  52  * until mmap() is called with @index as the offset.
  53  */
  54 #define IOCTL_GNTDEV_MAP_GRANT_REF \
  55 _IOC(_IOC_NONE, 'G', 0, sizeof(struct ioctl_gntdev_map_grant_ref))
  56 struct ioctl_gntdev_map_grant_ref {
  57         /* IN parameters */
  58         /* The number of grants to be mapped. */
  59         uint32_t count;
  60         uint32_t pad;
  61         /* OUT parameters */
  62         /* The offset to be used on a subsequent call to mmap(). */
  63         uint64_t index;
  64         /* Variable IN parameter. */
  65         /* Array of grant references, of size @count. */
  66         struct ioctl_gntdev_grant_ref refs[1];
  67 };
  68
  69 /*
  70  * Removes the grant references from the mapping table of an instance of
  71  * of gntdev. N.B. munmap() must be called on the relevant virtual address(es)
  72  * before this ioctl is called, or an error will result.
  73  */
  74 #define IOCTL_GNTDEV_UNMAP_GRANT_REF \
  75 _IOC(_IOC_NONE, 'G', 1, sizeof(struct ioctl_gntdev_unmap_grant_ref))
  76 struct ioctl_gntdev_unmap_grant_ref {
  77         /* IN parameters */
  78         /* The offset was returned by the corresponding map operation. */
  79         uint64_t index;
  80         /* The number of pages to be unmapped. */
  81         uint32_t count;
  82         uint32_t pad;
  83 };
  84
  85 /*
  86  * Returns the offset in the driver's address space that corresponds
  87  * to @vaddr. This can be used to perform a munmap(), followed by an
  88  * UNMAP_GRANT_REF ioctl, where no state about the offset is retained by
  89  * the caller. The number of pages that were allocated at the same time as
  90  * @vaddr is returned in @count.
  91  *
  92  * N.B. Where more than one page has been mapped into a contiguous range, the
  93  *      supplied @vaddr must correspond to the start of the range; otherwise
  94  *      an error will result. It is only possible to munmap() the entire
  95  *      contiguously-allocated range at once, and not any subrange thereof.
  96  */
  97 #define IOCTL_GNTDEV_GET_OFFSET_FOR_VADDR \
  98 _IOC(_IOC_NONE, 'G', 2, sizeof(struct ioctl_gntdev_get_offset_for_vaddr))
  99 struct ioctl_gntdev_get_offset_for_vaddr {
 100         /* IN parameters */
 101         /* The virtual address of the first mapped page in a range. */
 102         uint64_t vaddr;
 103         /* OUT parameters */
 104         /* The offset that was used in the initial mmap() operation. */
 105         uint64_t offset;
 106         /* The number of pages mapped in the VM area that begins at @vaddr. */
 107         uint32_t count;
 108         uint32_t pad;
 109 };
 110
 111 /*
 112  * Sets the maximum number of grants that may mapped at once by this gntdev
 113  * instance.
 114  *
 115  * N.B. This must be called before any other ioctl is performed on the device.
 116  */
 117 #define IOCTL_GNTDEV_SET_MAX_GRANTS \
 118 _IOC(_IOC_NONE, 'G', 3, sizeof(struct ioctl_gntdev_set_max_grants))
 119 struct ioctl_gntdev_set_max_grants {
 120         /* IN parameter */
 121         /* The maximum number of grants that may be mapped at once. */
 122         uint32_t count;
 123 };
 124
 125 /*
 126  * Sets up an unmap notification within the page, so that the other side can do
 127  * cleanup if this side crashes. Required to implement cross-domain robust
 128  * mutexes or close notification on communication channels.
 129  *
 130  * Each mapped page only supports one notification; multiple calls referring to
 131  * the same page overwrite the previous notification. You must clear the
 132  * notification prior to the IOCTL_GNTALLOC_DEALLOC_GREF if you do not want it
 133  * to occur.
 134  */
 135 #define IOCTL_GNTDEV_SET_UNMAP_NOTIFY \
 136 _IOC(_IOC_NONE, 'G', 7, sizeof(struct ioctl_gntdev_unmap_notify))
 137 struct ioctl_gntdev_unmap_notify {
 138         /* IN parameters */
 139         /* Offset in the file descriptor for a byte within the page (same as
 140          * used in mmap). If using UNMAP_NOTIFY_CLEAR_BYTE, this is the byte to
 141          * be cleared. Otherwise, it can be any byte in the page whose
 142          * notification we are adjusting.
 143          */
 144         uint64_t index;
 145         /* Action(s) to take on unmap */
 146         uint32_t action;
 147         /* Event channel to notify */
 148         uint32_t event_channel_port;
 149 };
 150
 151 /* Clear (set to zero) the byte specified by index */
 152 #define UNMAP_NOTIFY_CLEAR_BYTE 0x1
 153 /* Send an interrupt on the indicated event channel */
 154 #define UNMAP_NOTIFY_SEND_EVENT 0x2
 155
 156 #endif /* __LINUX_PUBLIC_GNTDEV_H__ */