2 * Copyright(c) 2015 Intel Corporation. All rights reserved.
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.
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.
17 #include <linux/uio.h>
19 #ifdef CONFIG_ARCH_HAS_PMEM_API
20 #define ARCH_MEMREMAP_PMEM MEMREMAP_WB
23 #define ARCH_MEMREMAP_PMEM MEMREMAP_WT
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.
29 static inline bool __arch_has_wmb_pmem(void)
34 static inline void arch_wmb_pmem(void)
39 static inline void arch_memcpy_to_pmem(void __pmem
*dst
, const void *src
,
45 static inline size_t arch_copy_from_iter_pmem(void __pmem
*addr
, size_t bytes
,
52 static inline void arch_clear_pmem(void __pmem
*addr
, size_t size
)
59 * Architectures that define ARCH_HAS_PMEM_API must provide
60 * implementations for arch_memcpy_to_pmem(), arch_wmb_pmem(),
61 * arch_copy_from_iter_pmem(), arch_clear_pmem() and arch_has_wmb_pmem().
63 static inline void memcpy_from_pmem(void *dst
, void __pmem
const *src
, size_t size
)
65 memcpy(dst
, (void __force
const *) src
, size
);
68 static inline void memunmap_pmem(struct device
*dev
, void __pmem
*addr
)
70 devm_memunmap(dev
, (void __force
*) addr
);
73 static inline bool arch_has_pmem_api(void)
75 return IS_ENABLED(CONFIG_ARCH_HAS_PMEM_API
);
79 * arch_has_wmb_pmem - true if wmb_pmem() ensures durability
81 * For a given cpu implementation within an architecture it is possible
82 * that wmb_pmem() resolves to a nop. In the case this returns
83 * false, pmem api users are unable to ensure durability and may want to
84 * fall back to a different data consistency model, or otherwise notify
87 static inline bool arch_has_wmb_pmem(void)
89 return arch_has_pmem_api() && __arch_has_wmb_pmem();
93 * These defaults seek to offer decent performance and minimize the
94 * window between i/o completion and writes being durable on media.
95 * However, it is undefined / architecture specific whether
96 * default_memremap_pmem + default_memcpy_to_pmem is sufficient for
97 * making data durable relative to i/o completion.
99 static inline void default_memcpy_to_pmem(void __pmem
*dst
, const void *src
,
102 memcpy((void __force
*) dst
, src
, size
);
105 static inline size_t default_copy_from_iter_pmem(void __pmem
*addr
,
106 size_t bytes
, struct iov_iter
*i
)
108 return copy_from_iter_nocache((void __force
*)addr
, bytes
, i
);
111 static inline void default_clear_pmem(void __pmem
*addr
, size_t size
)
113 if (size
== PAGE_SIZE
&& ((unsigned long)addr
& ~PAGE_MASK
) == 0)
114 clear_page((void __force
*)addr
);
116 memset((void __force
*)addr
, 0, size
);
120 * memremap_pmem - map physical persistent memory for pmem api
121 * @offset: physical address of persistent memory
122 * @size: size of the mapping
124 * Establish a mapping of the architecture specific memory type expected
125 * by memcpy_to_pmem() and wmb_pmem(). For example, it may be
126 * the case that an uncacheable or writethrough mapping is sufficient,
127 * or a writeback mapping provided memcpy_to_pmem() and
128 * wmb_pmem() arrange for the data to be written through the
129 * cache to persistent media.
131 static inline void __pmem
*memremap_pmem(struct device
*dev
,
132 resource_size_t offset
, unsigned long size
)
134 return (void __pmem
*) devm_memremap(dev
, offset
, size
,
139 * memcpy_to_pmem - copy data to persistent memory
140 * @dst: destination buffer for the copy
141 * @src: source buffer for the copy
142 * @n: length of the copy in bytes
144 * Perform a memory copy that results in the destination of the copy
145 * being effectively evicted from, or never written to, the processor
146 * cache hierarchy after the copy completes. After memcpy_to_pmem()
147 * data may still reside in cpu or platform buffers, so this operation
148 * must be followed by a wmb_pmem().
150 static inline void memcpy_to_pmem(void __pmem
*dst
, const void *src
, size_t n
)
152 if (arch_has_pmem_api())
153 arch_memcpy_to_pmem(dst
, src
, n
);
155 default_memcpy_to_pmem(dst
, src
, n
);
159 * wmb_pmem - synchronize writes to persistent memory
161 * After a series of memcpy_to_pmem() operations this drains data from
162 * cpu write buffers and any platform (memory controller) buffers to
163 * ensure that written data is durable on persistent memory media.
165 static inline void wmb_pmem(void)
167 if (arch_has_wmb_pmem())
174 * copy_from_iter_pmem - copy data from an iterator to PMEM
175 * @addr: PMEM destination address
176 * @bytes: number of bytes to copy
177 * @i: iterator with source data
179 * Copy data from the iterator 'i' to the PMEM buffer starting at 'addr'.
180 * This function requires explicit ordering with a wmb_pmem() call.
182 static inline size_t copy_from_iter_pmem(void __pmem
*addr
, size_t bytes
,
185 if (arch_has_pmem_api())
186 return arch_copy_from_iter_pmem(addr
, bytes
, i
);
187 return default_copy_from_iter_pmem(addr
, bytes
, i
);
191 * clear_pmem - zero a PMEM memory range
192 * @addr: virtual start address
193 * @size: number of bytes to zero
195 * Write zeros into the memory range starting at 'addr' for 'size' bytes.
196 * This function requires explicit ordering with a wmb_pmem() call.
198 static inline void clear_pmem(void __pmem
*addr
, size_t size
)
200 if (arch_has_pmem_api())
201 arch_clear_pmem(addr
, size
);
203 default_clear_pmem(addr
, size
);
205 #endif /* __PMEM_H__ */
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