310 lines
		
	
	
		
			10 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			310 lines
		
	
	
		
			10 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /* SPDX-License-Identifier: ((GPL-2.0 WITH Linux-syscall-note) OR MIT) */
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| /******************************************************************************
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|  * gntdev.h
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|  * 
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|  * Interface to /dev/xen/gntdev.
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|  * 
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|  * Copyright (c) 2007, D G Murray
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|  * Copyright (c) 2018, Oleksandr Andrushchenko, EPAM Systems Inc.
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|  * 
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|  * This program is free software; you can redistribute it and/or
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|  * modify it under the terms of the GNU General Public License version 2
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|  * as published by the Free Software Foundation; or, when distributed
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|  * separately from the Linux kernel or incorporated into other
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|  * software packages, subject to the following license:
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|  * 
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|  * Permission is hereby granted, free of charge, to any person obtaining a copy
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|  * of this source file (the "Software"), to deal in the Software without
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|  * restriction, including without limitation the rights to use, copy, modify,
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|  * merge, publish, distribute, sublicense, and/or sell copies of the Software,
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|  * and to permit persons to whom the Software is furnished to do so, subject to
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|  * the following conditions:
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|  * 
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|  * The above copyright notice and this permission notice shall be included in
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|  * all copies or substantial portions of the Software.
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|  * 
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|  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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|  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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|  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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|  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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|  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
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|  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
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|  * IN THE SOFTWARE.
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|  */
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| 
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| #ifndef __LINUX_PUBLIC_GNTDEV_H__
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| #define __LINUX_PUBLIC_GNTDEV_H__
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| 
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| #include <linux/types.h>
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| 
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| struct ioctl_gntdev_grant_ref {
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| 	/* The domain ID of the grant to be mapped. */
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| 	__u32 domid;
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| 	/* The grant reference of the grant to be mapped. */
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| 	__u32 ref;
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| };
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| 
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| /*
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|  * Inserts the grant references into the mapping table of an instance
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|  * of gntdev. N.B. This does not perform the mapping, which is deferred
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|  * until mmap() is called with @index as the offset.
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|  */
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| #define IOCTL_GNTDEV_MAP_GRANT_REF \
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| _IOC(_IOC_NONE, 'G', 0, sizeof(struct ioctl_gntdev_map_grant_ref))
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| struct ioctl_gntdev_map_grant_ref {
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| 	/* IN parameters */
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| 	/* The number of grants to be mapped. */
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| 	__u32 count;
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| 	__u32 pad;
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| 	/* OUT parameters */
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| 	/* The offset to be used on a subsequent call to mmap(). */
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| 	__u64 index;
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| 	/* Variable IN parameter. */
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| 	/* Array of grant references, of size @count. */
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| 	struct ioctl_gntdev_grant_ref refs[1];
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| };
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| 
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| /*
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|  * Removes the grant references from the mapping table of an instance of
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|  * of gntdev. N.B. munmap() must be called on the relevant virtual address(es)
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|  * before this ioctl is called, or an error will result.
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|  */
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| #define IOCTL_GNTDEV_UNMAP_GRANT_REF \
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| _IOC(_IOC_NONE, 'G', 1, sizeof(struct ioctl_gntdev_unmap_grant_ref))
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| struct ioctl_gntdev_unmap_grant_ref {
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| 	/* IN parameters */
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| 	/* The offset was returned by the corresponding map operation. */
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| 	__u64 index;
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| 	/* The number of pages to be unmapped. */
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| 	__u32 count;
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| 	__u32 pad;
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| };
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| 
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| /*
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|  * Returns the offset in the driver's address space that corresponds
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|  * to @vaddr. This can be used to perform a munmap(), followed by an
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|  * UNMAP_GRANT_REF ioctl, where no state about the offset is retained by
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|  * the caller. The number of pages that were allocated at the same time as
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|  * @vaddr is returned in @count.
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|  *
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|  * N.B. Where more than one page has been mapped into a contiguous range, the
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|  *      supplied @vaddr must correspond to the start of the range; otherwise
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|  *      an error will result. It is only possible to munmap() the entire
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|  *      contiguously-allocated range at once, and not any subrange thereof.
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|  */
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| #define IOCTL_GNTDEV_GET_OFFSET_FOR_VADDR \
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| _IOC(_IOC_NONE, 'G', 2, sizeof(struct ioctl_gntdev_get_offset_for_vaddr))
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| struct ioctl_gntdev_get_offset_for_vaddr {
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| 	/* IN parameters */
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| 	/* The virtual address of the first mapped page in a range. */
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| 	__u64 vaddr;
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| 	/* OUT parameters */
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| 	/* The offset that was used in the initial mmap() operation. */
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| 	__u64 offset;
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| 	/* The number of pages mapped in the VM area that begins at @vaddr. */
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| 	__u32 count;
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| 	__u32 pad;
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| };
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| 
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| /*
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|  * Sets the maximum number of grants that may mapped at once by this gntdev
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|  * instance.
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|  *
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|  * N.B. This must be called before any other ioctl is performed on the device.
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|  */
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| #define IOCTL_GNTDEV_SET_MAX_GRANTS \
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| _IOC(_IOC_NONE, 'G', 3, sizeof(struct ioctl_gntdev_set_max_grants))
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| struct ioctl_gntdev_set_max_grants {
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| 	/* IN parameter */
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| 	/* The maximum number of grants that may be mapped at once. */
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| 	__u32 count;
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| };
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| 
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| /*
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|  * Sets up an unmap notification within the page, so that the other side can do
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|  * cleanup if this side crashes. Required to implement cross-domain robust
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|  * mutexes or close notification on communication channels.
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|  *
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|  * Each mapped page only supports one notification; multiple calls referring to
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|  * the same page overwrite the previous notification. You must clear the
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|  * notification prior to the IOCTL_GNTALLOC_DEALLOC_GREF if you do not want it
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|  * to occur.
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|  */
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| #define IOCTL_GNTDEV_SET_UNMAP_NOTIFY \
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| _IOC(_IOC_NONE, 'G', 7, sizeof(struct ioctl_gntdev_unmap_notify))
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| struct ioctl_gntdev_unmap_notify {
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| 	/* IN parameters */
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| 	/* Offset in the file descriptor for a byte within the page (same as
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| 	 * used in mmap). If using UNMAP_NOTIFY_CLEAR_BYTE, this is the byte to
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| 	 * be cleared. Otherwise, it can be any byte in the page whose
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| 	 * notification we are adjusting.
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| 	 */
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| 	__u64 index;
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| 	/* Action(s) to take on unmap */
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| 	__u32 action;
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| 	/* Event channel to notify */
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| 	__u32 event_channel_port;
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| };
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| 
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| struct gntdev_grant_copy_segment {
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| 	union {
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| 		void __user *virt;
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| 		struct {
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| 			grant_ref_t ref;
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| 			__u16 offset;
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| 			domid_t domid;
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| 		} foreign;
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| 	} source, dest;
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| 	__u16 len;
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| 
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| 	__u16 flags;  /* GNTCOPY_* */
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| 	__s16 status; /* GNTST_* */
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| };
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| 
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| /*
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|  * Copy between grant references and local buffers.
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|  *
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|  * The copy is split into @count @segments, each of which can copy
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|  * to/from one grant reference.
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|  *
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|  * Each segment is similar to struct gnttab_copy in the hypervisor ABI
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|  * except the local buffer is specified using a virtual address
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|  * (instead of a GFN and offset).
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|  *
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|  * The local buffer may cross a Xen page boundary -- the driver will
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|  * split segments into multiple ops if required.
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|  *
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|  * Returns 0 if all segments have been processed and @status in each
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|  * segment is valid.  Note that one or more segments may have failed
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|  * (status != GNTST_okay).
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|  *
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|  * If the driver had to split a segment into two or more ops, @status
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|  * includes the status of the first failed op for that segment (or
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|  * GNTST_okay if all ops were successful).
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|  *
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|  * If -1 is returned, the status of all segments is undefined.
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|  *
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|  * EINVAL: A segment has local buffers for both source and
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|  *         destination.
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|  * EINVAL: A segment crosses the boundary of a foreign page.
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|  * EFAULT: A segment's local buffer is not accessible.
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|  */
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| #define IOCTL_GNTDEV_GRANT_COPY \
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| 	_IOC(_IOC_NONE, 'G', 8, sizeof(struct ioctl_gntdev_grant_copy))
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| struct ioctl_gntdev_grant_copy {
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| 	unsigned int count;
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| 	struct gntdev_grant_copy_segment __user *segments;
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| };
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| 
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| /* Clear (set to zero) the byte specified by index */
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| #define UNMAP_NOTIFY_CLEAR_BYTE 0x1
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| /* Send an interrupt on the indicated event channel */
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| #define UNMAP_NOTIFY_SEND_EVENT 0x2
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| 
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| /*
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|  * Flags to be used while requesting memory mapping's backing storage
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|  * to be allocated with DMA API.
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|  */
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| 
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| /*
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|  * The buffer is backed with memory allocated with dma_alloc_wc.
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|  */
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| #define GNTDEV_DMA_FLAG_WC		(1 << 0)
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| 
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| /*
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|  * The buffer is backed with memory allocated with dma_alloc_coherent.
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|  */
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| #define GNTDEV_DMA_FLAG_COHERENT	(1 << 1)
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| 
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| /*
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|  * Create a dma-buf [1] from grant references @refs of count @count provided
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|  * by the foreign domain @domid with flags @flags.
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|  *
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|  * By default dma-buf is backed by system memory pages, but by providing
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|  * one of the GNTDEV_DMA_FLAG_XXX flags it can also be created as
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|  * a DMA write-combine or coherent buffer, e.g. allocated with dma_alloc_wc/
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|  * dma_alloc_coherent.
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|  *
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|  * Returns 0 if dma-buf was successfully created and the corresponding
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|  * dma-buf's file descriptor is returned in @fd.
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|  *
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|  * [1] Documentation/driver-api/dma-buf.rst
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|  */
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| 
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| #define IOCTL_GNTDEV_DMABUF_EXP_FROM_REFS \
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| 	_IOC(_IOC_NONE, 'G', 9, \
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| 	     sizeof(struct ioctl_gntdev_dmabuf_exp_from_refs))
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| struct ioctl_gntdev_dmabuf_exp_from_refs {
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| 	/* IN parameters. */
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| 	/* Specific options for this dma-buf: see GNTDEV_DMA_FLAG_XXX. */
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| 	__u32 flags;
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| 	/* Number of grant references in @refs array. */
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| 	__u32 count;
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| 	/* OUT parameters. */
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| 	/* File descriptor of the dma-buf. */
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| 	__u32 fd;
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| 	/* The domain ID of the grant references to be mapped. */
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| 	__u32 domid;
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| 	/* Variable IN parameter. */
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| 	/* Array of grant references of size @count. */
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| 	__u32 refs[1];
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| };
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| 
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| /*
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|  * This will block until the dma-buf with the file descriptor @fd is
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|  * released. This is only valid for buffers created with
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|  * IOCTL_GNTDEV_DMABUF_EXP_FROM_REFS.
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|  *
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|  * If within @wait_to_ms milliseconds the buffer is not released
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|  * then -ETIMEDOUT error is returned.
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|  * If the buffer with the file descriptor @fd does not exist or has already
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|  * been released, then -ENOENT is returned. For valid file descriptors
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|  * this must not be treated as error.
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|  */
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| #define IOCTL_GNTDEV_DMABUF_EXP_WAIT_RELEASED \
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| 	_IOC(_IOC_NONE, 'G', 10, \
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| 	     sizeof(struct ioctl_gntdev_dmabuf_exp_wait_released))
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| struct ioctl_gntdev_dmabuf_exp_wait_released {
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| 	/* IN parameters */
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| 	__u32 fd;
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| 	__u32 wait_to_ms;
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| };
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| 
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| /*
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|  * Import a dma-buf with file descriptor @fd and export granted references
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|  * to the pages of that dma-buf into array @refs of size @count.
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|  */
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| #define IOCTL_GNTDEV_DMABUF_IMP_TO_REFS \
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| 	_IOC(_IOC_NONE, 'G', 11, \
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| 	     sizeof(struct ioctl_gntdev_dmabuf_imp_to_refs))
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| struct ioctl_gntdev_dmabuf_imp_to_refs {
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| 	/* IN parameters. */
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| 	/* File descriptor of the dma-buf. */
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| 	__u32 fd;
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| 	/* Number of grant references in @refs array. */
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| 	__u32 count;
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| 	/* The domain ID for which references to be granted. */
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| 	__u32 domid;
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| 	/* Reserved - must be zero. */
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| 	__u32 reserved;
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| 	/* OUT parameters. */
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| 	/* Array of grant references of size @count. */
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| 	__u32 refs[1];
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| };
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| 
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| /*
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|  * This will close all references to the imported buffer with file descriptor
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|  * @fd, so it can be released by the owner. This is only valid for buffers
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|  * created with IOCTL_GNTDEV_DMABUF_IMP_TO_REFS.
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|  */
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| #define IOCTL_GNTDEV_DMABUF_IMP_RELEASE \
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| 	_IOC(_IOC_NONE, 'G', 12, \
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| 	     sizeof(struct ioctl_gntdev_dmabuf_imp_release))
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| struct ioctl_gntdev_dmabuf_imp_release {
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| 	/* IN parameters */
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| 	__u32 fd;
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| 	__u32 reserved;
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| };
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| 
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| #endif /* __LINUX_PUBLIC_GNTDEV_H__ */
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