/* 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 { … }; /* * 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. @index should be * considered opaque to userspace, with one exception: if no grant * references have ever been inserted into the mapping table of this * instance, @index will be set to 0. This is necessary to use gntdev * with userspace APIs that expect a file descriptor that can be * mmap()'d at offset 0, such as Wayland. If @count is set to 0, this * ioctl will fail. */ #define IOCTL_GNTDEV_MAP_GRANT_REF … struct ioctl_gntdev_map_grant_ref { … }; /* * Removes the grant references from the mapping table of an instance 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 … struct ioctl_gntdev_unmap_grant_ref { … }; /* * 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 … struct ioctl_gntdev_get_offset_for_vaddr { … }; /* * 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 … struct ioctl_gntdev_set_max_grants { … }; /* * 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 … struct ioctl_gntdev_unmap_notify { … }; struct gntdev_grant_copy_segment { … }; /* * 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 … struct ioctl_gntdev_grant_copy { … }; /* Clear (set to zero) the byte specified by index */ #define UNMAP_NOTIFY_CLEAR_BYTE … /* Send an interrupt on the indicated event channel */ #define UNMAP_NOTIFY_SEND_EVENT … /* * 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 … /* * The buffer is backed with memory allocated with dma_alloc_coherent. */ #define GNTDEV_DMA_FLAG_COHERENT … /* * 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 … struct ioctl_gntdev_dmabuf_exp_from_refs { … }; /* * 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 … struct ioctl_gntdev_dmabuf_exp_wait_released { … }; /* * 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 … struct ioctl_gntdev_dmabuf_imp_to_refs { … }; /* * 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 … struct ioctl_gntdev_dmabuf_imp_release { … }; #endif /* __LINUX_PUBLIC_GNTDEV_H__ */
Codebase Browser
linux