diff mbox

[5/9] x86, pmem: use __mcsafe_copy() for memcpy_from_pmem()

Message ID 20160106072313.40900.12731.stgit@dwillia2-desk3.amr.corp.intel.com
State New, archived
Headers show

Commit Message

Dan Williams Jan. 6, 2016, 7:23 a.m. UTC
In support of large capacity persistent memory use __mcsafe_copy() for
pmem I/O.  This allows the pmem driver to support an error model similar
to disks when machine check recovery is available.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: x86@kernel.org
Cc: Borislav Petkov <bp@suse.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
 arch/x86/include/asm/pmem.h |   16 ++++++++++++++++
 drivers/nvdimm/Kconfig      |    1 +
 drivers/nvdimm/pmem.c       |   10 ++++++----
 include/linux/pmem.h        |   17 +++++++++++++----
 4 files changed, 36 insertions(+), 8 deletions(-)


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diff mbox

Patch

diff --git a/arch/x86/include/asm/pmem.h b/arch/x86/include/asm/pmem.h
index d8ce3ec816ab..4ef301e78a2b 100644
--- a/arch/x86/include/asm/pmem.h
+++ b/arch/x86/include/asm/pmem.h
@@ -17,6 +17,7 @@ 
 #include <asm/cacheflush.h>
 #include <asm/cpufeature.h>
 #include <asm/special_insns.h>
+#include <asm/string.h>
 
 #ifdef CONFIG_ARCH_HAS_PMEM_API
 /**
@@ -47,6 +48,21 @@  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 (IS_ENABLED(CONFIG_MCE_KERNEL_RECOVERY)) {
+		struct mcsafe_ret ret;
+
+		ret = __mcsafe_copy(dst, (void __force *) src, n);
+		if (ret.remain)
+			return -EIO;
+		return 0;
+	}
+	memcpy(dst, (void __force *) src, n);
+	return 0;
+}
+
 /**
  * arch_wmb_pmem - synchronize writes to persistent memory
  *
diff --git a/drivers/nvdimm/Kconfig b/drivers/nvdimm/Kconfig
index 53c11621d5b1..fe5885d01fd8 100644
--- a/drivers/nvdimm/Kconfig
+++ b/drivers/nvdimm/Kconfig
@@ -22,6 +22,7 @@  config BLK_DEV_PMEM
 	depends on HAS_IOMEM
 	select ND_BTT if BTT
 	select ND_PFN if NVDIMM_PFN
+	select MCE_KERNEL_RECOVERY if X86_MCE && X86_64
 	help
 	  Memory ranges for PMEM are described by either an NFIT
 	  (NVDIMM Firmware Interface Table, see CONFIG_NFIT_ACPI), a
diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
index 8744235b5be2..d8e14e962327 100644
--- a/drivers/nvdimm/pmem.c
+++ b/drivers/nvdimm/pmem.c
@@ -62,6 +62,7 @@  static bool is_bad_pmem(struct badblocks *bb, sector_t sector, unsigned int len)
 static int pmem_do_bvec(struct block_device *bdev, struct page *page,
 		unsigned int len, unsigned int off, int rw, sector_t sector)
 {
+	int rc = 0;
 	void *mem = kmap_atomic(page);
 	struct gendisk *disk = bdev->bd_disk;
 	struct pmem_device *pmem = disk->private_data;
@@ -71,7 +72,7 @@  static int pmem_do_bvec(struct block_device *bdev, struct page *page,
 	if (rw == READ) {
 		if (unlikely(is_bad_pmem(disk->bb, sector, len)))
 			return -EIO;
-		memcpy_from_pmem(mem + off, pmem_addr, len);
+		rc = memcpy_from_pmem(mem + off, pmem_addr, len);
 		flush_dcache_page(page);
 	} else {
 		flush_dcache_page(page);
@@ -79,7 +80,7 @@  static int pmem_do_bvec(struct block_device *bdev, struct page *page,
 	}
 
 	kunmap_atomic(mem);
-	return 0;
+	return rc;
 }
 
 static blk_qc_t pmem_make_request(struct request_queue *q, struct bio *bio)
@@ -237,6 +238,7 @@  static int pmem_rw_bytes(struct nd_namespace_common *ndns,
 		resource_size_t offset, void *buf, size_t size, int rw)
 {
 	struct pmem_device *pmem = dev_get_drvdata(ndns->claim);
+	int rc = 0;
 
 	if (unlikely(offset + size > pmem->size)) {
 		dev_WARN_ONCE(&ndns->dev, 1, "request out of range\n");
@@ -244,13 +246,13 @@  static int pmem_rw_bytes(struct nd_namespace_common *ndns,
 	}
 
 	if (rw == READ)
-		memcpy_from_pmem(buf, pmem->virt_addr + offset, size);
+		rc = memcpy_from_pmem(buf, pmem->virt_addr + offset, size);
 	else {
 		memcpy_to_pmem(pmem->virt_addr + offset, buf, size);
 		wmb_pmem();
 	}
 
-	return 0;
+	return rc;
 }
 
 static int nd_pfn_init(struct nd_pfn *nd_pfn)
diff --git a/include/linux/pmem.h b/include/linux/pmem.h
index acfea8ce4a07..0e57a5beab21 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 0;
+}
+
 static inline size_t arch_copy_from_iter_pmem(void __pmem *addr, size_t bytes,
 		struct iov_iter *i)
 {
@@ -57,12 +64,14 @@  static inline void arch_clear_pmem(void __pmem *addr, size_t size)
 
 /*
  * 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() and arch_has_wmb_pmem().
+ * implementations for arch_memcpy_to_pmem(), arch_memcpy_from_pmem(),
+ * arch_wmb_pmem(), arch_copy_from_iter_pmem(), arch_clear_pmem() and
+ * arch_has_wmb_pmem().
  */
-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)