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git.proxmox.com Git - mirror_ubuntu-zesty-kernel.git/blob - include/linux/pmem.h
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 int arch_memcpy_from_pmem(void *dst
, const void __pmem
*src
,
52 static inline size_t arch_copy_from_iter_pmem(void __pmem
*addr
, size_t bytes
,
59 static inline void arch_clear_pmem(void __pmem
*addr
, size_t size
)
64 static inline void arch_wb_cache_pmem(void __pmem
*addr
, size_t size
)
69 static inline void arch_invalidate_pmem(void __pmem
*addr
, size_t size
)
76 * memcpy_from_pmem - read from persistent memory with error handling
77 * @dst: destination buffer
79 * @size: transfer length
81 * Returns 0 on success negative error code on failure.
83 static inline int memcpy_from_pmem(void *dst
, void __pmem
const *src
,
86 return arch_memcpy_from_pmem(dst
, src
, size
);
89 static inline bool arch_has_pmem_api(void)
91 return IS_ENABLED(CONFIG_ARCH_HAS_PMEM_API
);
95 * arch_has_wmb_pmem - true if wmb_pmem() ensures durability
97 * For a given cpu implementation within an architecture it is possible
98 * that wmb_pmem() resolves to a nop. In the case this returns
99 * false, pmem api users are unable to ensure durability and may want to
100 * fall back to a different data consistency model, or otherwise notify
103 static inline bool arch_has_wmb_pmem(void)
105 return arch_has_pmem_api() && __arch_has_wmb_pmem();
109 * These defaults seek to offer decent performance and minimize the
110 * window between i/o completion and writes being durable on media.
111 * However, it is undefined / architecture specific whether
112 * ARCH_MEMREMAP_PMEM + default_memcpy_to_pmem is sufficient for
113 * making data durable relative to i/o completion.
115 static inline void default_memcpy_to_pmem(void __pmem
*dst
, const void *src
,
118 memcpy((void __force
*) dst
, src
, size
);
121 static inline size_t default_copy_from_iter_pmem(void __pmem
*addr
,
122 size_t bytes
, struct iov_iter
*i
)
124 return copy_from_iter_nocache((void __force
*)addr
, bytes
, i
);
127 static inline void default_clear_pmem(void __pmem
*addr
, size_t size
)
129 if (size
== PAGE_SIZE
&& ((unsigned long)addr
& ~PAGE_MASK
) == 0)
130 clear_page((void __force
*)addr
);
132 memset((void __force
*)addr
, 0, size
);
136 * memcpy_to_pmem - copy data to persistent memory
137 * @dst: destination buffer for the copy
138 * @src: source buffer for the copy
139 * @n: length of the copy in bytes
141 * Perform a memory copy that results in the destination of the copy
142 * being effectively evicted from, or never written to, the processor
143 * cache hierarchy after the copy completes. After memcpy_to_pmem()
144 * data may still reside in cpu or platform buffers, so this operation
145 * must be followed by a wmb_pmem().
147 static inline void memcpy_to_pmem(void __pmem
*dst
, const void *src
, size_t n
)
149 if (arch_has_pmem_api())
150 arch_memcpy_to_pmem(dst
, src
, n
);
152 default_memcpy_to_pmem(dst
, src
, n
);
156 * wmb_pmem - synchronize writes to persistent memory
158 * After a series of memcpy_to_pmem() operations this drains data from
159 * cpu write buffers and any platform (memory controller) buffers to
160 * ensure that written data is durable on persistent memory media.
162 static inline void wmb_pmem(void)
164 if (arch_has_wmb_pmem())
171 * copy_from_iter_pmem - copy data from an iterator to PMEM
172 * @addr: PMEM destination address
173 * @bytes: number of bytes to copy
174 * @i: iterator with source data
176 * Copy data from the iterator 'i' to the PMEM buffer starting at 'addr'.
177 * This function requires explicit ordering with a wmb_pmem() call.
179 static inline size_t copy_from_iter_pmem(void __pmem
*addr
, size_t bytes
,
182 if (arch_has_pmem_api())
183 return arch_copy_from_iter_pmem(addr
, bytes
, i
);
184 return default_copy_from_iter_pmem(addr
, bytes
, i
);
188 * clear_pmem - zero a PMEM memory range
189 * @addr: virtual start address
190 * @size: number of bytes to zero
192 * Write zeros into the memory range starting at 'addr' for 'size' bytes.
193 * This function requires explicit ordering with a wmb_pmem() call.
195 static inline void clear_pmem(void __pmem
*addr
, size_t size
)
197 if (arch_has_pmem_api())
198 arch_clear_pmem(addr
, size
);
200 default_clear_pmem(addr
, size
);
204 * invalidate_pmem - flush a pmem range from the cache hierarchy
205 * @addr: virtual start address
206 * @size: bytes to invalidate (internally aligned to cache line size)
208 * For platforms that support clearing poison this flushes any poisoned
209 * ranges out of the cache
211 static inline void invalidate_pmem(void __pmem
*addr
, size_t size
)
213 if (arch_has_pmem_api())
214 arch_invalidate_pmem(addr
, size
);
218 * wb_cache_pmem - write back processor cache for PMEM memory range
219 * @addr: virtual start address
220 * @size: number of bytes to write back
222 * Write back the processor cache range starting at 'addr' for 'size' bytes.
223 * This function requires explicit ordering with a wmb_pmem() call.
225 static inline void wb_cache_pmem(void __pmem
*addr
, size_t size
)
227 if (arch_has_pmem_api())
228 arch_wb_cache_pmem(addr
, size
);
230 #endif /* __PMEM_H__ */