2015-08-19 02:55:36 +07:00
|
|
|
/*
|
|
|
|
* Copyright(c) 2015 Intel Corporation. All rights reserved.
|
|
|
|
*
|
|
|
|
* This program is free software; you can redistribute it and/or modify
|
|
|
|
* it under the terms of version 2 of the GNU General Public License as
|
|
|
|
* published by the Free Software Foundation.
|
|
|
|
*
|
|
|
|
* This program is distributed in the hope that it will be useful, but
|
|
|
|
* WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
|
|
* General Public License for more details.
|
|
|
|
*/
|
|
|
|
#ifndef __ASM_X86_PMEM_H__
|
|
|
|
#define __ASM_X86_PMEM_H__
|
|
|
|
|
|
|
|
#include <linux/uaccess.h>
|
|
|
|
#include <asm/cacheflush.h>
|
|
|
|
#include <asm/cpufeature.h>
|
|
|
|
#include <asm/special_insns.h>
|
|
|
|
|
|
|
|
#ifdef ARCH_HAS_NOCACHE_UACCESS
|
|
|
|
|
|
|
|
/**
|
|
|
|
* arch_memcpy_to_pmem - copy data to persistent memory
|
|
|
|
* @dst: destination buffer for the copy
|
|
|
|
* @src: source buffer for the copy
|
|
|
|
* @n: length of the copy in bytes
|
|
|
|
*
|
|
|
|
* Copy data to persistent memory media via non-temporal stores so that
|
|
|
|
* a subsequent arch_wmb_pmem() can flush cpu and memory controller
|
|
|
|
* write buffers to guarantee durability.
|
|
|
|
*/
|
|
|
|
static inline void arch_memcpy_to_pmem(void __pmem *dst, const void *src,
|
|
|
|
size_t n)
|
|
|
|
{
|
|
|
|
int unwritten;
|
|
|
|
|
|
|
|
/*
|
|
|
|
* We are copying between two kernel buffers, if
|
|
|
|
* __copy_from_user_inatomic_nocache() returns an error (page
|
|
|
|
* fault) we would have already reported a general protection fault
|
|
|
|
* before the WARN+BUG.
|
|
|
|
*/
|
|
|
|
unwritten = __copy_from_user_inatomic_nocache((void __force *) dst,
|
|
|
|
(void __user *) src, n);
|
|
|
|
if (WARN(unwritten, "%s: fault copying %p <- %p unwritten: %d\n",
|
|
|
|
__func__, dst, src, unwritten))
|
|
|
|
BUG();
|
|
|
|
}
|
|
|
|
|
|
|
|
/**
|
|
|
|
* arch_wmb_pmem - synchronize writes to persistent memory
|
|
|
|
*
|
|
|
|
* After a series of arch_memcpy_to_pmem() operations this drains data
|
|
|
|
* from cpu write buffers and any platform (memory controller) buffers
|
|
|
|
* to ensure that written data is durable on persistent memory media.
|
|
|
|
*/
|
|
|
|
static inline void arch_wmb_pmem(void)
|
|
|
|
{
|
|
|
|
/*
|
|
|
|
* wmb() to 'sfence' all previous writes such that they are
|
|
|
|
* architecturally visible to 'pcommit'. Note, that we've
|
|
|
|
* already arranged for pmem writes to avoid the cache via
|
|
|
|
* arch_memcpy_to_pmem().
|
|
|
|
*/
|
|
|
|
wmb();
|
|
|
|
pcommit_sfence();
|
|
|
|
}
|
|
|
|
|
2015-08-19 02:55:37 +07:00
|
|
|
static inline bool arch_has_wmb_pmem(void)
|
2015-08-19 02:55:36 +07:00
|
|
|
{
|
|
|
|
#ifdef CONFIG_X86_64
|
|
|
|
/*
|
|
|
|
* We require that wmb() be an 'sfence', that is only guaranteed on
|
|
|
|
* 64-bit builds
|
|
|
|
*/
|
|
|
|
return static_cpu_has(X86_FEATURE_PCOMMIT);
|
|
|
|
#else
|
|
|
|
return false;
|
|
|
|
#endif
|
|
|
|
}
|
|
|
|
#else /* ARCH_HAS_NOCACHE_UACCESS i.e. ARCH=um */
|
|
|
|
extern void arch_memcpy_to_pmem(void __pmem *dst, const void *src, size_t n);
|
|
|
|
extern void arch_wmb_pmem(void);
|
|
|
|
|
|
|
|
static inline bool __arch_has_wmb_pmem(void)
|
|
|
|
{
|
|
|
|
return false;
|
|
|
|
}
|
|
|
|
#endif
|
|
|
|
|
|
|
|
#endif /* __ASM_X86_PMEM_H__ */
|