x86, dax, pmem: remove indirection around memcpy_from_pmem()

memcpy_from_pmem() maps directly to memcpy_mcsafe(). The wrapper
serves no real benefit aside from affording a more generic function name
than the x86-specific 'mcsafe'. However this would not be the first time
that x86 terminology leaked into the global namespace. For lack of
better name, just use memcpy_mcsafe() directly.

This conversion also catches a place where we should have been using
plain memcpy, acpi_nfit_blk_single_io().

Cc: <x86@kernel.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Jeff Moyer <jmoyer@redhat.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Acked-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

7 files changed, 12 insertions, 32 deletions

diff --git a/arch/x86/include/asm/pmem.h b/arch/x86/include/asm/pmem.h
index 529bb4a6487a..d5a22bac9988 100644
--- a/arch/x86/include/asm/pmem.h
+++ b/arch/x86/include/asm/pmem.h
@@ -44,11 +44,6 @@ static inline void arch_memcpy_to_pmem(void *dst, const void *src, size_t n)
                 BUG();
 }
 
-static inline int arch_memcpy_from_pmem(void *dst, const void *src, size_t n)
-{
-        return memcpy_mcsafe(dst, src, n);
-}
-
 /**
  * arch_wb_cache_pmem - write back a cache range with CLWB
  * @vaddr:      virtual start address
diff --git a/arch/x86/include/asm/string_64.h b/arch/x86/include/asm/string_64.h
index a164862d77e3..733bae07fb29 100644
--- a/arch/x86/include/asm/string_64.h
+++ b/arch/x86/include/asm/string_64.h
@@ -79,6 +79,7 @@ int strcmp(const char *cs, const char *ct);
 #define memset(s, c, n) __memset(s, c, n)
 #endif
 
+#define __HAVE_ARCH_MEMCPY_MCSAFE 1
 __must_check int memcpy_mcsafe_unrolled(void *dst, const void *src, size_t cnt);
 DECLARE_STATIC_KEY_FALSE(mcsafe_key);
 
diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c
index c8ea9d698cd0..d0c07b2344e4 100644
--- a/drivers/acpi/nfit/core.c
+++ b/drivers/acpi/nfit/core.c
@@ -1783,8 +1783,7 @@ static int acpi_nfit_blk_single_io(struct nfit_blk *nfit_blk,
                                 mmio_flush_range((void __force *)
                                         mmio->addr.aperture + offset, c);
 
-                        memcpy_from_pmem(iobuf + copied,
-                                        mmio->addr.aperture + offset, c);
+                        memcpy(iobuf + copied, mmio->addr.aperture + offset, c);
                 }
 
                 copied += c;
diff --git a/drivers/nvdimm/claim.c b/drivers/nvdimm/claim.c
index ca6d572c48fc..3a35e8028b9c 100644
--- a/drivers/nvdimm/claim.c
+++ b/drivers/nvdimm/claim.c
@@ -239,7 +239,7 @@ static int nsio_rw_bytes(struct nd_namespace_common *ndns,
         if (rw == READ) {
                 if (unlikely(is_bad_pmem(&nsio->bb, sector, sz_align)))
                         return -EIO;
-                return memcpy_from_pmem(buf, nsio->addr + offset, size);
+                return memcpy_mcsafe(buf, nsio->addr + offset, size);
         }
 
         if (unlikely(is_bad_pmem(&nsio->bb, sector, sz_align))) {
diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
index 85b85633d674..3b3dab73d741 100644
--- a/drivers/nvdimm/pmem.c
+++ b/drivers/nvdimm/pmem.c
@@ -89,7 +89,7 @@ static int read_pmem(struct page *page, unsigned int off,
         int rc;
         void *mem = kmap_atomic(page);
 
-        rc = memcpy_from_pmem(mem + off, pmem_addr, len);
+        rc = memcpy_mcsafe(mem + off, pmem_addr, len);
         kunmap_atomic(mem);
         if (rc)
                 return -EIO;
diff --git a/include/linux/pmem.h b/include/linux/pmem.h
index e856c2cb0fe8..71ecf3d46aac 100644
--- a/include/linux/pmem.h
+++ b/include/linux/pmem.h
@@ -31,12 +31,6 @@ static inline void arch_memcpy_to_pmem(void *dst, const void *src, size_t n)
         BUG();
 }
 
-static inline int arch_memcpy_from_pmem(void *dst, const void *src, size_t n)
-{
-        BUG();
-        return -EFAULT;
-}
-
 static inline size_t arch_copy_from_iter_pmem(void *addr, size_t bytes,
                 struct iov_iter *i)
 {
@@ -65,23 +59,6 @@ static inline bool arch_has_pmem_api(void)
         return IS_ENABLED(CONFIG_ARCH_HAS_PMEM_API);
 }
 
-/*
- * memcpy_from_pmem - read from persistent memory with error handling
- * @dst: destination buffer
- * @src: source buffer
- * @size: transfer length
- *
- * Returns 0 on success negative error code on failure.
- */
-static inline int memcpy_from_pmem(void *dst, void const *src, size_t size)
-{
-        if (arch_has_pmem_api())
-                return arch_memcpy_from_pmem(dst, src, size);
-        else
-                memcpy(dst, src, size);
-        return 0;
-}
-
 /**
  * memcpy_to_pmem - copy data to persistent memory
  * @dst: destination buffer for the copy
diff --git a/include/linux/string.h b/include/linux/string.h
index 26b6f6a66f83..9d6f189157e2 100644
--- a/include/linux/string.h
+++ b/include/linux/string.h
@@ -114,6 +114,14 @@ extern int memcmp(const void *,const void *,__kernel_size_t);
 #ifndef __HAVE_ARCH_MEMCHR
 extern void * memchr(const void *,int,__kernel_size_t);
 #endif
+#ifndef __HAVE_ARCH_MEMCPY_MCSAFE
+static inline __must_check int memcpy_mcsafe(void *dst, const void *src,
+                size_t cnt)
+{
+        memcpy(dst, src, cnt);
+        return 0;
+}
+#endif
 void *memchr_inv(const void *s, int c, size_t n);
 char *strreplace(char *s, char old, char new);