[PATCH v2 2/7] pmem, x86: move x86 PMEM API to new pmem.h header

From: Ross Zwisler
Date: Thu Aug 13 2015 - 12:51:51 EST


Move the x86 PMEM API implementation out of asm/cacheflush.h and into
its own header asm/pmem.h. This will allow members of the PMEM API to
be more easily identified on this and other architectures.

Signed-off-by: Ross Zwisler <ross.zwisler@xxxxxxxxxxxxxxx>
Suggested-by: Christoph Hellwig <hch@xxxxxx>
---
MAINTAINERS | 1 +
arch/x86/include/asm/cacheflush.h | 71 ------------------------------
arch/x86/include/asm/pmem.h | 92 +++++++++++++++++++++++++++++++++++++++
include/linux/pmem.h | 2 +-
4 files changed, 94 insertions(+), 72 deletions(-)
create mode 100644 arch/x86/include/asm/pmem.h

diff --git a/MAINTAINERS b/MAINTAINERS
index a9ae6c1..d0b5a08 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -6165,6 +6165,7 @@ Q: https://patchwork.kernel.org/project/linux-nvdimm/list/
S: Supported
F: drivers/nvdimm/pmem.c
F: include/linux/pmem.h
+F: arch/*/include/asm/pmem.h

LINUX FOR IBM pSERIES (RS/6000)
M: Paul Mackerras <paulus@xxxxxxxxxx>
diff --git a/arch/x86/include/asm/cacheflush.h b/arch/x86/include/asm/cacheflush.h
index 9bf3ea1..471418a 100644
--- a/arch/x86/include/asm/cacheflush.h
+++ b/arch/x86/include/asm/cacheflush.h
@@ -109,75 +109,4 @@ static inline int rodata_test(void)
}
#endif

-#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();
-}
-
-static inline bool __arch_has_wmb_pmem(void)
-{
-#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_CACHEFLUSH_H */
diff --git a/arch/x86/include/asm/pmem.h b/arch/x86/include/asm/pmem.h
new file mode 100644
index 0000000..f43462c
--- /dev/null
+++ b/arch/x86/include/asm/pmem.h
@@ -0,0 +1,92 @@
+/*
+ * 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();
+}
+
+static inline bool __arch_has_wmb_pmem(void)
+{
+#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__ */
diff --git a/include/linux/pmem.h b/include/linux/pmem.h
index d211404..5dad6d1 100644
--- a/include/linux/pmem.h
+++ b/include/linux/pmem.h
@@ -16,7 +16,7 @@
#include <linux/io.h>

#ifdef CONFIG_ARCH_HAS_PMEM_API
-#include <asm/cacheflush.h>
+#include <asm/pmem.h>
#else
static inline void arch_wmb_pmem(void)
{
--
2.1.0

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