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 */
arch_memcpy_to_pmem(void * dst,const void * src,size_t n)29 static inline void arch_memcpy_to_pmem(void *dst, const void *src, size_t n)
30 {
31 BUG();
32 }
33
arch_memcpy_from_pmem(void * dst,const void * src,size_t n)34 static inline int arch_memcpy_from_pmem(void *dst, const void *src, size_t n)
35 {
36 BUG();
37 return -EFAULT;
38 }
39
arch_copy_from_iter_pmem(void * addr,size_t bytes,struct iov_iter * i)40 static 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
arch_clear_pmem(void * addr,size_t size)47 static inline void arch_clear_pmem(void *addr, size_t size)
48 {
49 BUG();
50 }
51
arch_wb_cache_pmem(void * addr,size_t size)52 static inline void arch_wb_cache_pmem(void *addr, size_t size)
53 {
54 BUG();
55 }
56
arch_invalidate_pmem(void * addr,size_t size)57 static inline void arch_invalidate_pmem(void *addr, size_t size)
58 {
59 BUG();
60 }
61 #endif
62
arch_has_pmem_api(void)63 static 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 */
memcpy_from_pmem(void * dst,void const * src,size_t size)76 static 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 */
memcpy_to_pmem(void * dst,const void * src,size_t n)97 static 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 */
copy_from_iter_pmem(void * addr,size_t bytes,struct iov_iter * i)114 static 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 */
clear_pmem(void * addr,size_t size)130 static 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 */
invalidate_pmem(void * addr,size_t size)146 static 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 */
wb_cache_pmem(void * addr,size_t size)160 static 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__ */
166