18279b467a
Prior to this change arch_has_wmb_pmem() was only called by arch_has_pmem_api(). Both arch_has_wmb_pmem() and arch_has_pmem_api() checked to make sure that CONFIG_ARCH_HAS_PMEM_API was enabled. Instead, remove the old arch_has_wmb_pmem() wrapper to be rid of one extra layer of indirection and the redundant CONFIG_ARCH_HAS_PMEM_API check. Rename __arch_has_wmb_pmem() to arch_has_wmb_pmem() since we no longer have a wrapper, and just have arch_has_pmem_api() call the architecture specific arch_has_wmb_pmem() directly. Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
93 lines
2.6 KiB
C
93 lines
2.6 KiB
C
/*
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* Copyright(c) 2015 Intel Corporation. All rights reserved.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of version 2 of the GNU General Public License as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*/
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#ifndef __ASM_X86_PMEM_H__
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#define __ASM_X86_PMEM_H__
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#include <linux/uaccess.h>
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#include <asm/cacheflush.h>
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#include <asm/cpufeature.h>
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#include <asm/special_insns.h>
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#ifdef ARCH_HAS_NOCACHE_UACCESS
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/**
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* arch_memcpy_to_pmem - copy data to persistent memory
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* @dst: destination buffer for the copy
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* @src: source buffer for the copy
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* @n: length of the copy in bytes
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*
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* Copy data to persistent memory media via non-temporal stores so that
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* a subsequent arch_wmb_pmem() can flush cpu and memory controller
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* write buffers to guarantee durability.
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*/
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static inline void arch_memcpy_to_pmem(void __pmem *dst, const void *src,
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size_t n)
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{
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int unwritten;
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/*
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* We are copying between two kernel buffers, if
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* __copy_from_user_inatomic_nocache() returns an error (page
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* fault) we would have already reported a general protection fault
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* before the WARN+BUG.
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*/
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unwritten = __copy_from_user_inatomic_nocache((void __force *) dst,
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(void __user *) src, n);
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if (WARN(unwritten, "%s: fault copying %p <- %p unwritten: %d\n",
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__func__, dst, src, unwritten))
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BUG();
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}
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/**
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* arch_wmb_pmem - synchronize writes to persistent memory
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*
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* After a series of arch_memcpy_to_pmem() operations this drains data
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* from cpu write buffers and any platform (memory controller) buffers
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* to ensure that written data is durable on persistent memory media.
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*/
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static inline void arch_wmb_pmem(void)
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{
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/*
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* wmb() to 'sfence' all previous writes such that they are
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* architecturally visible to 'pcommit'. Note, that we've
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* already arranged for pmem writes to avoid the cache via
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* arch_memcpy_to_pmem().
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*/
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wmb();
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pcommit_sfence();
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}
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static inline bool arch_has_wmb_pmem(void)
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{
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#ifdef CONFIG_X86_64
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/*
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* We require that wmb() be an 'sfence', that is only guaranteed on
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* 64-bit builds
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*/
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return static_cpu_has(X86_FEATURE_PCOMMIT);
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#else
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return false;
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#endif
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}
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#else /* ARCH_HAS_NOCACHE_UACCESS i.e. ARCH=um */
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extern void arch_memcpy_to_pmem(void __pmem *dst, const void *src, size_t n);
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extern void arch_wmb_pmem(void);
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static inline bool __arch_has_wmb_pmem(void)
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{
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return false;
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}
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#endif
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#endif /* __ASM_X86_PMEM_H__ */
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