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)
57 static inline void arch_wb_cache_pmem(void __pmem *addr, size_t size)
62 static inline void arch_invalidate_pmem(void __pmem *addr, size_t size)
69 * Architectures that define ARCH_HAS_PMEM_API must provide
70 * implementations for arch_memcpy_to_pmem(), arch_wmb_pmem(),
71 * arch_copy_from_iter_pmem(), arch_clear_pmem(), arch_wb_cache_pmem()
72 * and arch_has_wmb_pmem().
74 static inline void memcpy_from_pmem(void *dst, void __pmem const *src, size_t size)
76 memcpy(dst, (void __force const *) src, size);
79 static inline bool arch_has_pmem_api(void)
81 return IS_ENABLED(CONFIG_ARCH_HAS_PMEM_API);
85 * arch_has_wmb_pmem - true if wmb_pmem() ensures durability
87 * For a given cpu implementation within an architecture it is possible
88 * that wmb_pmem() resolves to a nop. In the case this returns
89 * false, pmem api users are unable to ensure durability and may want to
90 * fall back to a different data consistency model, or otherwise notify
93 static inline bool arch_has_wmb_pmem(void)
95 return arch_has_pmem_api() && __arch_has_wmb_pmem();
99 * These defaults seek to offer decent performance and minimize the
100 * window between i/o completion and writes being durable on media.
101 * However, it is undefined / architecture specific whether
102 * ARCH_MEMREMAP_PMEM + default_memcpy_to_pmem is sufficient for
103 * making data durable relative to i/o completion.
105 static inline void default_memcpy_to_pmem(void __pmem *dst, const void *src,
108 memcpy((void __force *) dst, src, size);
111 static inline size_t default_copy_from_iter_pmem(void __pmem *addr,
112 size_t bytes, struct iov_iter *i)
114 return copy_from_iter_nocache((void __force *)addr, bytes, i);
117 static inline void default_clear_pmem(void __pmem *addr, size_t size)
119 if (size == PAGE_SIZE && ((unsigned long)addr & ~PAGE_MASK) == 0)
120 clear_page((void __force *)addr);
122 memset((void __force *)addr, 0, size);
126 * memcpy_to_pmem - copy data to persistent memory
127 * @dst: destination buffer for the copy
128 * @src: source buffer for the copy
129 * @n: length of the copy in bytes
131 * Perform a memory copy that results in the destination of the copy
132 * being effectively evicted from, or never written to, the processor
133 * cache hierarchy after the copy completes. After memcpy_to_pmem()
134 * data may still reside in cpu or platform buffers, so this operation
135 * must be followed by a wmb_pmem().
137 static inline void memcpy_to_pmem(void __pmem *dst, const void *src, size_t n)
139 if (arch_has_pmem_api())
140 arch_memcpy_to_pmem(dst, src, n);
142 default_memcpy_to_pmem(dst, src, n);
146 * wmb_pmem - synchronize writes to persistent memory
148 * After a series of memcpy_to_pmem() operations this drains data from
149 * cpu write buffers and any platform (memory controller) buffers to
150 * ensure that written data is durable on persistent memory media.
152 static inline void wmb_pmem(void)
154 if (arch_has_wmb_pmem())
161 * copy_from_iter_pmem - copy data from an iterator to PMEM
162 * @addr: PMEM destination address
163 * @bytes: number of bytes to copy
164 * @i: iterator with source data
166 * Copy data from the iterator 'i' to the PMEM buffer starting at 'addr'.
167 * This function requires explicit ordering with a wmb_pmem() call.
169 static inline size_t copy_from_iter_pmem(void __pmem *addr, size_t bytes,
172 if (arch_has_pmem_api())
173 return arch_copy_from_iter_pmem(addr, bytes, i);
174 return default_copy_from_iter_pmem(addr, bytes, i);
178 * clear_pmem - zero a PMEM memory range
179 * @addr: virtual start address
180 * @size: number of bytes to zero
182 * Write zeros into the memory range starting at 'addr' for 'size' bytes.
183 * This function requires explicit ordering with a wmb_pmem() call.
185 static inline void clear_pmem(void __pmem *addr, size_t size)
187 if (arch_has_pmem_api())
188 arch_clear_pmem(addr, size);
190 default_clear_pmem(addr, size);
194 * invalidate_pmem - flush a pmem range from the cache hierarchy
195 * @addr: virtual start address
196 * @size: bytes to invalidate (internally aligned to cache line size)
198 * For platforms that support clearing poison this flushes any poisoned
199 * ranges out of the cache
201 static inline void invalidate_pmem(void __pmem *addr, size_t size)
203 if (arch_has_pmem_api())
204 arch_invalidate_pmem(addr, size);
208 * wb_cache_pmem - write back processor cache for PMEM memory range
209 * @addr: virtual start address
210 * @size: number of bytes to write back
212 * Write back the processor cache range starting at 'addr' for 'size' bytes.
213 * This function requires explicit ordering with a wmb_pmem() call.
215 static inline void wb_cache_pmem(void __pmem *addr, size_t size)
217 if (arch_has_pmem_api())
218 arch_wb_cache_pmem(addr, size);
220 #endif /* __PMEM_H__ */