Commit | Line | Data |
---|---|---|
61031952 RZ |
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> | |
5de490da | 17 | #include <linux/uio.h> |
61031952 RZ |
18 | |
19 | #ifdef CONFIG_ARCH_HAS_PMEM_API | |
96601adb | 20 | #define ARCH_MEMREMAP_PMEM MEMREMAP_WB |
40603526 | 21 | #include <asm/pmem.h> |
61031952 | 22 | #else |
96601adb DW |
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 | */ | |
29 | static inline bool __arch_has_wmb_pmem(void) | |
61031952 | 30 | { |
96601adb | 31 | return false; |
61031952 RZ |
32 | } |
33 | ||
96601adb | 34 | static inline void arch_wmb_pmem(void) |
61031952 | 35 | { |
96601adb | 36 | BUG(); |
61031952 RZ |
37 | } |
38 | ||
61031952 RZ |
39 | static inline void arch_memcpy_to_pmem(void __pmem *dst, const void *src, |
40 | size_t n) | |
41 | { | |
42 | BUG(); | |
43 | } | |
5de490da RZ |
44 | |
45 | static inline size_t arch_copy_from_iter_pmem(void __pmem *addr, size_t bytes, | |
46 | struct iov_iter *i) | |
47 | { | |
48 | BUG(); | |
49 | return 0; | |
50 | } | |
51 | ||
52 | static inline void arch_clear_pmem(void __pmem *addr, size_t size) | |
53 | { | |
54 | BUG(); | |
55 | } | |
61031952 RZ |
56 | #endif |
57 | ||
58 | /* | |
59 | * Architectures that define ARCH_HAS_PMEM_API must provide | |
5de490da RZ |
60 | * implementations for arch_memcpy_to_pmem(), arch_wmb_pmem(), |
61 | * arch_copy_from_iter_pmem(), arch_clear_pmem() and arch_has_wmb_pmem(). | |
61031952 | 62 | */ |
61031952 RZ |
63 | static inline void memcpy_from_pmem(void *dst, void __pmem const *src, size_t size) |
64 | { | |
65 | memcpy(dst, (void __force const *) src, size); | |
66 | } | |
67 | ||
96601adb DW |
68 | static inline bool arch_has_pmem_api(void) |
69 | { | |
70 | return IS_ENABLED(CONFIG_ARCH_HAS_PMEM_API); | |
71 | } | |
72 | ||
61031952 | 73 | /** |
96601adb | 74 | * arch_has_wmb_pmem - true if wmb_pmem() ensures durability |
61031952 RZ |
75 | * |
76 | * For a given cpu implementation within an architecture it is possible | |
77 | * that wmb_pmem() resolves to a nop. In the case this returns | |
78 | * false, pmem api users are unable to ensure durability and may want to | |
79 | * fall back to a different data consistency model, or otherwise notify | |
80 | * the user. | |
81 | */ | |
96601adb | 82 | static inline bool arch_has_wmb_pmem(void) |
61031952 | 83 | { |
96601adb | 84 | return arch_has_pmem_api() && __arch_has_wmb_pmem(); |
61031952 RZ |
85 | } |
86 | ||
87 | /* | |
88 | * These defaults seek to offer decent performance and minimize the | |
89 | * window between i/o completion and writes being durable on media. | |
90 | * However, it is undefined / architecture specific whether | |
a639315d | 91 | * ARCH_MEMREMAP_PMEM + default_memcpy_to_pmem is sufficient for |
61031952 RZ |
92 | * making data durable relative to i/o completion. |
93 | */ | |
e836a256 | 94 | static inline void default_memcpy_to_pmem(void __pmem *dst, const void *src, |
61031952 RZ |
95 | size_t size) |
96 | { | |
97 | memcpy((void __force *) dst, src, size); | |
98 | } | |
99 | ||
5de490da RZ |
100 | static inline size_t default_copy_from_iter_pmem(void __pmem *addr, |
101 | size_t bytes, struct iov_iter *i) | |
102 | { | |
103 | return copy_from_iter_nocache((void __force *)addr, bytes, i); | |
104 | } | |
105 | ||
106 | static inline void default_clear_pmem(void __pmem *addr, size_t size) | |
107 | { | |
108 | if (size == PAGE_SIZE && ((unsigned long)addr & ~PAGE_MASK) == 0) | |
109 | clear_page((void __force *)addr); | |
110 | else | |
111 | memset((void __force *)addr, 0, size); | |
112 | } | |
113 | ||
61031952 RZ |
114 | /** |
115 | * memcpy_to_pmem - copy data to persistent memory | |
116 | * @dst: destination buffer for the copy | |
117 | * @src: source buffer for the copy | |
118 | * @n: length of the copy in bytes | |
119 | * | |
120 | * Perform a memory copy that results in the destination of the copy | |
121 | * being effectively evicted from, or never written to, the processor | |
122 | * cache hierarchy after the copy completes. After memcpy_to_pmem() | |
123 | * data may still reside in cpu or platform buffers, so this operation | |
124 | * must be followed by a wmb_pmem(). | |
125 | */ | |
126 | static inline void memcpy_to_pmem(void __pmem *dst, const void *src, size_t n) | |
127 | { | |
128 | if (arch_has_pmem_api()) | |
129 | arch_memcpy_to_pmem(dst, src, n); | |
130 | else | |
131 | default_memcpy_to_pmem(dst, src, n); | |
132 | } | |
133 | ||
134 | /** | |
135 | * wmb_pmem - synchronize writes to persistent memory | |
136 | * | |
137 | * After a series of memcpy_to_pmem() operations this drains data from | |
138 | * cpu write buffers and any platform (memory controller) buffers to | |
139 | * ensure that written data is durable on persistent memory media. | |
140 | */ | |
141 | static inline void wmb_pmem(void) | |
142 | { | |
96601adb | 143 | if (arch_has_wmb_pmem()) |
61031952 | 144 | arch_wmb_pmem(); |
96601adb DW |
145 | else |
146 | wmb(); | |
61031952 | 147 | } |
5de490da RZ |
148 | |
149 | /** | |
150 | * copy_from_iter_pmem - copy data from an iterator to PMEM | |
151 | * @addr: PMEM destination address | |
152 | * @bytes: number of bytes to copy | |
153 | * @i: iterator with source data | |
154 | * | |
155 | * Copy data from the iterator 'i' to the PMEM buffer starting at 'addr'. | |
156 | * This function requires explicit ordering with a wmb_pmem() call. | |
157 | */ | |
158 | static inline size_t copy_from_iter_pmem(void __pmem *addr, size_t bytes, | |
159 | struct iov_iter *i) | |
160 | { | |
161 | if (arch_has_pmem_api()) | |
162 | return arch_copy_from_iter_pmem(addr, bytes, i); | |
163 | return default_copy_from_iter_pmem(addr, bytes, i); | |
164 | } | |
165 | ||
166 | /** | |
167 | * clear_pmem - zero a PMEM memory range | |
168 | * @addr: virtual start address | |
169 | * @size: number of bytes to zero | |
170 | * | |
171 | * Write zeros into the memory range starting at 'addr' for 'size' bytes. | |
172 | * This function requires explicit ordering with a wmb_pmem() call. | |
173 | */ | |
174 | static inline void clear_pmem(void __pmem *addr, size_t size) | |
175 | { | |
176 | if (arch_has_pmem_api()) | |
177 | arch_clear_pmem(addr, size); | |
178 | else | |
179 | default_clear_pmem(addr, size); | |
180 | } | |
61031952 | 181 | #endif /* __PMEM_H__ */ |