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