include/linux/pmem.h

   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  */
  29 static inline void arch_memcpy_to_pmem(void *dst, const void *src, size_t n)
  30 {
  31         BUG();
  32 }
  33
  34 static inline size_t arch_copy_from_iter_pmem(void *addr, size_t bytes,
  35                 struct iov_iter *i)
  36 {
  37         BUG();
  38         return 0;
  39 }
  40
  41 static inline void arch_clear_pmem(void *addr, size_t size)
  42 {
  43         BUG();
  44 }
  45
  46 static inline void arch_wb_cache_pmem(void *addr, size_t size)
  47 {
  48         BUG();
  49 }
  50
  51 static inline void arch_invalidate_pmem(void *addr, size_t size)
  52 {
  53         BUG();
  54 }
  55 #endif
  56
  57 static inline bool arch_has_pmem_api(void)
  58 {
  59         return IS_ENABLED(CONFIG_ARCH_HAS_PMEM_API);
  60 }
  61
  62 /**
  63  * memcpy_to_pmem - copy data to persistent memory
  64  * @dst: destination buffer for the copy
  65  * @src: source buffer for the copy
  66  * @n: length of the copy in bytes
  67  *
  68  * Perform a memory copy that results in the destination of the copy
  69  * being effectively evicted from, or never written to, the processor
  70  * cache hierarchy after the copy completes.  After memcpy_to_pmem()
  71  * data may still reside in cpu or platform buffers, so this operation
  72  * must be followed by a blkdev_issue_flush() on the pmem block device.
  73  */
  74 static inline void memcpy_to_pmem(void *dst, const void *src, size_t n)
  75 {
  76         if (arch_has_pmem_api())
  77                 arch_memcpy_to_pmem(dst, src, n);
  78         else
  79                 memcpy(dst, src, n);
  80 }
  81
  82 /**
  83  * copy_from_iter_pmem - copy data from an iterator to PMEM
  84  * @addr:       PMEM destination address
  85  * @bytes:      number of bytes to copy
  86  * @i:          iterator with source data
  87  *
  88  * Copy data from the iterator 'i' to the PMEM buffer starting at 'addr'.
  89  * See blkdev_issue_flush() note for memcpy_to_pmem().
  90  */
  91 static inline size_t copy_from_iter_pmem(void *addr, size_t bytes,
  92                 struct iov_iter *i)
  93 {
  94         if (arch_has_pmem_api())
  95                 return arch_copy_from_iter_pmem(addr, bytes, i);
  96         return copy_from_iter_nocache(addr, bytes, i);
  97 }
  98
  99 /**
 100  * clear_pmem - zero a PMEM memory range
 101  * @addr:       virtual start address
 102  * @size:       number of bytes to zero
 103  *
 104  * Write zeros into the memory range starting at 'addr' for 'size' bytes.
 105  * See blkdev_issue_flush() note for memcpy_to_pmem().
 106  */
 107 static inline void clear_pmem(void *addr, size_t size)
 108 {
 109         if (arch_has_pmem_api())
 110                 arch_clear_pmem(addr, size);
 111         else
 112                 memset(addr, 0, size);
 113 }
 114
 115 /**
 116  * invalidate_pmem - flush a pmem range from the cache hierarchy
 117  * @addr:       virtual start address
 118  * @size:       bytes to invalidate (internally aligned to cache line size)
 119  *
 120  * For platforms that support clearing poison this flushes any poisoned
 121  * ranges out of the cache
 122  */
 123 static inline void invalidate_pmem(void *addr, size_t size)
 124 {
 125         if (arch_has_pmem_api())
 126                 arch_invalidate_pmem(addr, size);
 127 }
 128
 129 /**
 130  * wb_cache_pmem - write back processor cache for PMEM memory range
 131  * @addr:       virtual start address
 132  * @size:       number of bytes to write back
 133  *
 134  * Write back the processor cache range starting at 'addr' for 'size' bytes.
 135  * See blkdev_issue_flush() note for memcpy_to_pmem().
 136  */
 137 static inline void wb_cache_pmem(void *addr, size_t size)
 138 {
 139         if (arch_has_pmem_api())
 140                 arch_wb_cache_pmem(addr, size);
 141 }
 142 #endif /* __PMEM_H__ */