path: root/contrib/libs/linux-headers/xen/gntdev.h

/* SPDX-License-Identifier: ((GPL-2.0 WITH Linux-syscall-note) OR MIT) */ 
/****************************************************************************** 
 * gntdev.h 
 *  
 * Interface to /dev/xen/gntdev. 
 *  
 * Copyright (c) 2007, D G Murray 
 * Copyright (c) 2018, Oleksandr Andrushchenko, EPAM Systems Inc. 
 *  
 * 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__ 
 
#include <linux/types.h> 
 
struct ioctl_gntdev_grant_ref { 
	/* The domain ID of the grant to be mapped. */ 
	__u32 domid; 
	/* The grant reference of the grant to be mapped. */ 
	__u32 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. */ 
	__u32 count; 
	__u32 pad; 
	/* OUT parameters */ 
	/* The offset to be used on a subsequent call to mmap(). */ 
	__u64 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. */ 
	__u64 index; 
	/* The number of pages to be unmapped. */ 
	__u32 count; 
	__u32 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. */ 
	__u64 vaddr; 
	/* OUT parameters */ 
	/* The offset that was used in the initial mmap() operation. */ 
	__u64 offset; 
	/* The number of pages mapped in the VM area that begins at @vaddr. */ 
	__u32 count; 
	__u32 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. */ 
	__u32 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. 
	 */ 
	__u64 index; 
	/* Action(s) to take on unmap */ 
	__u32 action; 
	/* Event channel to notify */ 
	__u32 event_channel_port; 
}; 
 
struct gntdev_grant_copy_segment { 
	union { 
		void *virt; 
		struct { 
			grant_ref_t ref; 
			__u16 offset; 
			domid_t domid; 
		} foreign; 
	} source, dest; 
	__u16 len; 
 
	__u16 flags;  /* GNTCOPY_* */ 
	__s16 status; /* GNTST_* */ 
}; 
 
/* 
 * Copy between grant references and local buffers. 
 * 
 * The copy is split into @count @segments, each of which can copy 
 * to/from one grant reference. 
 * 
 * Each segment is similar to struct gnttab_copy in the hypervisor ABI 
 * except the local buffer is specified using a virtual address 
 * (instead of a GFN and offset). 
 * 
 * The local buffer may cross a Xen page boundary -- the driver will 
 * split segments into multiple ops if required. 
 * 
 * Returns 0 if all segments have been processed and @status in each 
 * segment is valid.  Note that one or more segments may have failed 
 * (status != GNTST_okay). 
 * 
 * If the driver had to split a segment into two or more ops, @status 
 * includes the status of the first failed op for that segment (or 
 * GNTST_okay if all ops were successful). 
 * 
 * If -1 is returned, the status of all segments is undefined. 
 * 
 * EINVAL: A segment has local buffers for both source and 
 *         destination. 
 * EINVAL: A segment crosses the boundary of a foreign page. 
 * EFAULT: A segment's local buffer is not accessible. 
 */ 
#define IOCTL_GNTDEV_GRANT_COPY \ 
	_IOC(_IOC_NONE, 'G', 8, sizeof(struct ioctl_gntdev_grant_copy)) 
struct ioctl_gntdev_grant_copy { 
	unsigned int count; 
	struct gntdev_grant_copy_segment *segments; 
}; 
 
/* 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 
 
/* 
 * Flags to be used while requesting memory mapping's backing storage 
 * to be allocated with DMA API. 
 */ 
 
/* 
 * The buffer is backed with memory allocated with dma_alloc_wc. 
 */ 
#define GNTDEV_DMA_FLAG_WC		(1 << 0) 
 
/* 
 * The buffer is backed with memory allocated with dma_alloc_coherent. 
 */ 
#define GNTDEV_DMA_FLAG_COHERENT	(1 << 1) 
 
/* 
 * Create a dma-buf [1] from grant references @refs of count @count provided 
 * by the foreign domain @domid with flags @flags. 
 * 
 * By default dma-buf is backed by system memory pages, but by providing 
 * one of the GNTDEV_DMA_FLAG_XXX flags it can also be created as 
 * a DMA write-combine or coherent buffer, e.g. allocated with dma_alloc_wc/ 
 * dma_alloc_coherent. 
 * 
 * Returns 0 if dma-buf was successfully created and the corresponding 
 * dma-buf's file descriptor is returned in @fd. 
 * 
 * [1] Documentation/driver-api/dma-buf.rst 
 */ 
 
#define IOCTL_GNTDEV_DMABUF_EXP_FROM_REFS \ 
	_IOC(_IOC_NONE, 'G', 9, \ 
	     sizeof(struct ioctl_gntdev_dmabuf_exp_from_refs)) 
struct ioctl_gntdev_dmabuf_exp_from_refs { 
	/* IN parameters. */ 
	/* Specific options for this dma-buf: see GNTDEV_DMA_FLAG_XXX. */ 
	__u32 flags; 
	/* Number of grant references in @refs array. */ 
	__u32 count; 
	/* OUT parameters. */ 
	/* File descriptor of the dma-buf. */ 
	__u32 fd; 
	/* The domain ID of the grant references to be mapped. */ 
	__u32 domid; 
	/* Variable IN parameter. */ 
	/* Array of grant references of size @count. */ 
	__u32 refs[1]; 
}; 
 
/* 
 * This will block until the dma-buf with the file descriptor @fd is 
 * released. This is only valid for buffers created with 
 * IOCTL_GNTDEV_DMABUF_EXP_FROM_REFS. 
 * 
 * If within @wait_to_ms milliseconds the buffer is not released 
 * then -ETIMEDOUT error is returned. 
 * If the buffer with the file descriptor @fd does not exist or has already 
 * been released, then -ENOENT is returned. For valid file descriptors 
 * this must not be treated as error. 
 */ 
#define IOCTL_GNTDEV_DMABUF_EXP_WAIT_RELEASED \ 
	_IOC(_IOC_NONE, 'G', 10, \ 
	     sizeof(struct ioctl_gntdev_dmabuf_exp_wait_released)) 
struct ioctl_gntdev_dmabuf_exp_wait_released { 
	/* IN parameters */ 
	__u32 fd; 
	__u32 wait_to_ms; 
}; 
 
/* 
 * Import a dma-buf with file descriptor @fd and export granted references 
 * to the pages of that dma-buf into array @refs of size @count. 
 */ 
#define IOCTL_GNTDEV_DMABUF_IMP_TO_REFS \ 
	_IOC(_IOC_NONE, 'G', 11, \ 
	     sizeof(struct ioctl_gntdev_dmabuf_imp_to_refs)) 
struct ioctl_gntdev_dmabuf_imp_to_refs { 
	/* IN parameters. */ 
	/* File descriptor of the dma-buf. */ 
	__u32 fd; 
	/* Number of grant references in @refs array. */ 
	__u32 count; 
	/* The domain ID for which references to be granted. */ 
	__u32 domid; 
	/* Reserved - must be zero. */ 
	__u32 reserved; 
	/* OUT parameters. */ 
	/* Array of grant references of size @count. */ 
	__u32 refs[1]; 
}; 
 
/* 
 * This will close all references to the imported buffer with file descriptor 
 * @fd, so it can be released by the owner. This is only valid for buffers 
 * created with IOCTL_GNTDEV_DMABUF_IMP_TO_REFS. 
 */ 
#define IOCTL_GNTDEV_DMABUF_IMP_RELEASE \ 
	_IOC(_IOC_NONE, 'G', 12, \ 
	     sizeof(struct ioctl_gntdev_dmabuf_imp_release)) 
struct ioctl_gntdev_dmabuf_imp_release { 
	/* IN parameters */ 
	__u32 fd; 
	__u32 reserved; 
}; 
 
#endif /* __LINUX_PUBLIC_GNTDEV_H__ */