From fc0c2028135c7f75fce36b90e44efb8003a9173b Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Tue, 8 Mar 2016 10:30:19 -0800 Subject: [PATCH 1/1] x86, pmem: use memcpy_mcsafe() for memcpy_from_pmem() Update the definition of memcpy_from_pmem() to return 0 or a negative error code. Implement x86/arch_memcpy_from_pmem() with memcpy_mcsafe(). Cc: Borislav Petkov Cc: Tony Luck Cc: Thomas Gleixner Cc: Andy Lutomirski Cc: Peter Zijlstra Cc: Andrew Morton Cc: Linus Torvalds Acked-by: Ingo Molnar Reviewed-by: Ross Zwisler Signed-off-by: Dan Williams --- arch/x86/include/asm/pmem.h | 9 +++++++++ drivers/nvdimm/pmem.c | 4 ++-- include/linux/pmem.h | 22 ++++++++++++++++------ 3 files changed, 27 insertions(+), 8 deletions(-) diff --git a/arch/x86/include/asm/pmem.h b/arch/x86/include/asm/pmem.h index bf8b35d2035a..fbc5e92e1ecc 100644 --- a/arch/x86/include/asm/pmem.h +++ b/arch/x86/include/asm/pmem.h @@ -47,6 +47,15 @@ static inline void arch_memcpy_to_pmem(void __pmem *dst, const void *src, BUG(); } +static inline int arch_memcpy_from_pmem(void *dst, const void __pmem *src, + size_t n) +{ + if (static_cpu_has(X86_FEATURE_MCE_RECOVERY)) + return memcpy_mcsafe(dst, (void __force *) src, n); + memcpy(dst, (void __force *) src, n); + return 0; +} + /** * arch_wmb_pmem - synchronize writes to persistent memory * diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c index ca5721c306bb..cc31c6f1f88e 100644 --- a/drivers/nvdimm/pmem.c +++ b/drivers/nvdimm/pmem.c @@ -99,7 +99,7 @@ static int pmem_do_bvec(struct pmem_device *pmem, struct page *page, if (unlikely(bad_pmem)) rc = -EIO; else { - memcpy_from_pmem(mem + off, pmem_addr, len); + rc = memcpy_from_pmem(mem + off, pmem_addr, len); flush_dcache_page(page); } } else { @@ -295,7 +295,7 @@ static int pmem_rw_bytes(struct nd_namespace_common *ndns, if (unlikely(is_bad_pmem(&pmem->bb, offset / 512, sz_align))) return -EIO; - memcpy_from_pmem(buf, pmem->virt_addr + offset, size); + return memcpy_from_pmem(buf, pmem->virt_addr + offset, size); } else { memcpy_to_pmem(pmem->virt_addr + offset, buf, size); wmb_pmem(); diff --git a/include/linux/pmem.h b/include/linux/pmem.h index 3ec5309e29f3..ac6d872ce067 100644 --- a/include/linux/pmem.h +++ b/include/linux/pmem.h @@ -42,6 +42,13 @@ static inline void arch_memcpy_to_pmem(void __pmem *dst, const void *src, BUG(); } +static inline int arch_memcpy_from_pmem(void *dst, const void __pmem *src, + size_t n) +{ + BUG(); + return -EFAULT; +} + static inline size_t arch_copy_from_iter_pmem(void __pmem *addr, size_t bytes, struct iov_iter *i) { @@ -66,14 +73,17 @@ static inline void arch_invalidate_pmem(void __pmem *addr, size_t size) #endif /* - * Architectures that define ARCH_HAS_PMEM_API must provide - * implementations for arch_memcpy_to_pmem(), arch_wmb_pmem(), - * arch_copy_from_iter_pmem(), arch_clear_pmem(), arch_wb_cache_pmem() - * and arch_has_wmb_pmem(). + * 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 void memcpy_from_pmem(void *dst, void __pmem const *src, size_t size) +static inline int memcpy_from_pmem(void *dst, void __pmem const *src, + size_t size) { - memcpy(dst, (void __force const *) src, size); + return arch_memcpy_from_pmem(dst, src, size); } static inline bool arch_has_pmem_api(void) -- 2.34.1