--- /dev/null
+/* 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__ */
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