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1/* $OpenBSD: highmem.h,v 1.5 2025/02/07 03:03:31 jsg Exp $ */
2/*
3 * Copyright (c) 2013, 2014, 2015 Mark Kettenis
4 *
5 * Permission to use, copy, modify, and distribute this software for any
6 * purpose with or without fee is hereby granted, provided that the above
7 * copyright notice and this permission notice appear in all copies.
8 *
9 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16 */
17
18#ifndef _LINUX_HIGHMEM_H
19#define _LINUX_HIGHMEM_H
20
21#include <sys/param.h>
22#include <uvm/uvm_extern.h>
23#include <linux/uaccess.h>
24#include <asm/pgtable.h>
25
26void *kmap(struct vm_page *);
27void kunmap_va(void *addr);
28
29#define kmap_to_page(ptr) (ptr)
30
31void *kmap_atomic_prot(struct vm_page *, pgprot_t);
32void kunmap_atomic(void *);
33
34static inline void *
35kmap_atomic(struct vm_page *pg)
36{
37 return kmap_atomic_prot(pg, PAGE_KERNEL);
38}
39
40static inline void *
41kmap_local_page(struct vm_page *pg)
42{
43 return kmap_atomic(pg);
44}
45
46static inline void
47kunmap_local(void *addr)
48{
49 kunmap_atomic(addr);
50}
51
52static inline void
53memcpy_from_page(char *dst, struct vm_page *page, size_t off, size_t len)
54{
55 void *src = kmap_atomic(page);
56 memcpy(dst, src + off, len);
57 kunmap_atomic(src);
58}
59
60static inline void
61memcpy_to_page(struct vm_page *page, size_t off, const char *src, size_t len)
62{
63 char *dst = kmap_atomic(page);
64 memcpy(dst + off, src, len);
65 kunmap_atomic(dst);
66}
67
68#endif