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