Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
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linux
1/*
2 * Copyright(c) 2015 Intel Corporation. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of version 2 of the GNU General Public License as
6 * published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful, but
9 * WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 */
13#ifndef __PMEM_H__
14#define __PMEM_H__
15
16#include <linux/io.h>
17#include <linux/uio.h>
18
19#ifdef CONFIG_ARCH_HAS_PMEM_API
20#define ARCH_MEMREMAP_PMEM MEMREMAP_WB
21#include <asm/pmem.h>
22#else
23#define ARCH_MEMREMAP_PMEM MEMREMAP_WT
24/*
25 * These are simply here to enable compilation, all call sites gate
26 * calling these symbols with arch_has_pmem_api() and redirect to the
27 * implementation in asm/pmem.h.
28 */
29static inline void arch_memcpy_to_pmem(void *dst, const void *src, size_t n)
30{
31 BUG();
32}
33
34static inline int arch_memcpy_from_pmem(void *dst, const void *src, size_t n)
35{
36 BUG();
37 return -EFAULT;
38}
39
40static inline size_t arch_copy_from_iter_pmem(void *addr, size_t bytes,
41 struct iov_iter *i)
42{
43 BUG();
44 return 0;
45}
46
47static inline void arch_clear_pmem(void *addr, size_t size)
48{
49 BUG();
50}
51
52static inline void arch_wb_cache_pmem(void *addr, size_t size)
53{
54 BUG();
55}
56
57static inline void arch_invalidate_pmem(void *addr, size_t size)
58{
59 BUG();
60}
61#endif
62
63static inline bool arch_has_pmem_api(void)
64{
65 return IS_ENABLED(CONFIG_ARCH_HAS_PMEM_API);
66}
67
68/*
69 * memcpy_from_pmem - read from persistent memory with error handling
70 * @dst: destination buffer
71 * @src: source buffer
72 * @size: transfer length
73 *
74 * Returns 0 on success negative error code on failure.
75 */
76static inline int memcpy_from_pmem(void *dst, void const *src, size_t size)
77{
78 if (arch_has_pmem_api())
79 return arch_memcpy_from_pmem(dst, src, size);
80 else
81 memcpy(dst, src, size);
82 return 0;
83}
84
85/**
86 * memcpy_to_pmem - copy data to persistent memory
87 * @dst: destination buffer for the copy
88 * @src: source buffer for the copy
89 * @n: length of the copy in bytes
90 *
91 * Perform a memory copy that results in the destination of the copy
92 * being effectively evicted from, or never written to, the processor
93 * cache hierarchy after the copy completes. After memcpy_to_pmem()
94 * data may still reside in cpu or platform buffers, so this operation
95 * must be followed by a blkdev_issue_flush() on the pmem block device.
96 */
97static inline void memcpy_to_pmem(void *dst, const void *src, size_t n)
98{
99 if (arch_has_pmem_api())
100 arch_memcpy_to_pmem(dst, src, n);
101 else
102 memcpy(dst, src, n);
103}
104
105/**
106 * copy_from_iter_pmem - copy data from an iterator to PMEM
107 * @addr: PMEM destination address
108 * @bytes: number of bytes to copy
109 * @i: iterator with source data
110 *
111 * Copy data from the iterator 'i' to the PMEM buffer starting at 'addr'.
112 * See blkdev_issue_flush() note for memcpy_to_pmem().
113 */
114static inline size_t copy_from_iter_pmem(void *addr, size_t bytes,
115 struct iov_iter *i)
116{
117 if (arch_has_pmem_api())
118 return arch_copy_from_iter_pmem(addr, bytes, i);
119 return copy_from_iter_nocache(addr, bytes, i);
120}
121
122/**
123 * clear_pmem - zero a PMEM memory range
124 * @addr: virtual start address
125 * @size: number of bytes to zero
126 *
127 * Write zeros into the memory range starting at 'addr' for 'size' bytes.
128 * See blkdev_issue_flush() note for memcpy_to_pmem().
129 */
130static inline void clear_pmem(void *addr, size_t size)
131{
132 if (arch_has_pmem_api())
133 arch_clear_pmem(addr, size);
134 else
135 memset(addr, 0, size);
136}
137
138/**
139 * invalidate_pmem - flush a pmem range from the cache hierarchy
140 * @addr: virtual start address
141 * @size: bytes to invalidate (internally aligned to cache line size)
142 *
143 * For platforms that support clearing poison this flushes any poisoned
144 * ranges out of the cache
145 */
146static inline void invalidate_pmem(void *addr, size_t size)
147{
148 if (arch_has_pmem_api())
149 arch_invalidate_pmem(addr, size);
150}
151
152/**
153 * wb_cache_pmem - write back processor cache for PMEM memory range
154 * @addr: virtual start address
155 * @size: number of bytes to write back
156 *
157 * Write back the processor cache range starting at 'addr' for 'size' bytes.
158 * See blkdev_issue_flush() note for memcpy_to_pmem().
159 */
160static inline void wb_cache_pmem(void *addr, size_t size)
161{
162 if (arch_has_pmem_api())
163 arch_wb_cache_pmem(addr, size);
164}
165#endif /* __PMEM_H__ */