Update the definition of memcpy_from_pmem() to return 0 or -EIO on error. Implement x86::arch_memcpy_from_pmem() with memcpy_mcsafe().
Cc: Borislav Petkov <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Tony Luck <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Ross Zwisler <[email protected]> Cc: Linus Torvalds <[email protected]> Signed-off-by: Dan Williams <[email protected]> --- Note that this patch is built on a merge of tip/ras/core, tip/x86/asm, and nvdimm/for-4.6/acpi6.1 for the following reasons (respectively): 1/ memcpy_mcsafe() itself 2/ X86_FEATURE_MCE_RECOVERY cpu capability 3/ merge with the new 'clear poison' implementation: https://lists.01.org/pipermail/linux-nvdimm/2016-March/004826.html arch/x86/include/asm/pmem.h | 9 +++++++++ drivers/nvdimm/pmem.c | 4 ++-- include/linux/pmem.h | 14 ++++++++------ 3 files changed, 19 insertions(+), 8 deletions(-) diff --git a/arch/x86/include/asm/pmem.h b/arch/x86/include/asm/pmem.h index bf8b35d2035a..4df3820535c6 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) ? 0 : -EIO; + 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 adc387236fe7..2022d08c60ce 100644 --- a/drivers/nvdimm/pmem.c +++ b/drivers/nvdimm/pmem.c @@ -98,7 +98,7 @@ 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..c46c5cf6538e 100644 --- a/include/linux/pmem.h +++ b/include/linux/pmem.h @@ -66,14 +66,16 @@ 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 + * + * Returns 0 on success -EIO 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)
