From 59e6473980f321c16299e12db69d1fabc2644a6f Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Tue, 8 Mar 2016 07:16:07 -0800 Subject: [PATCH] libnvdimm, pmem: clear poison on write If a write is directed at a known bad block perform the following: 1/ write the data 2/ send a clear poison command 3/ invalidate the poison out of the cache hierarchy Cc: Cc: Ross Zwisler Reviewed-by: Vishal Verma Signed-off-by: Dan Williams --- arch/x86/include/asm/pmem.h | 5 ++++ drivers/nvdimm/bus.c | 46 +++++++++++++++++++++++++++++++++++++ drivers/nvdimm/nd.h | 2 ++ drivers/nvdimm/pmem.c | 29 ++++++++++++++++++++++- include/linux/pmem.h | 19 +++++++++++++++ 5 files changed, 100 insertions(+), 1 deletion(-) diff --git a/arch/x86/include/asm/pmem.h b/arch/x86/include/asm/pmem.h index c57fd1ea9689..bf8b35d2035a 100644 --- a/arch/x86/include/asm/pmem.h +++ b/arch/x86/include/asm/pmem.h @@ -137,6 +137,11 @@ static inline void arch_clear_pmem(void __pmem *addr, size_t size) arch_wb_cache_pmem(addr, size); } +static inline void arch_invalidate_pmem(void __pmem *addr, size_t size) +{ + clflush_cache_range((void __force *) addr, size); +} + static inline bool __arch_has_wmb_pmem(void) { /* diff --git a/drivers/nvdimm/bus.c b/drivers/nvdimm/bus.c index cb6fd64b13e3..33557481d452 100644 --- a/drivers/nvdimm/bus.c +++ b/drivers/nvdimm/bus.c @@ -159,6 +159,52 @@ void nvdimm_region_notify(struct nd_region *nd_region, enum nvdimm_event event) } EXPORT_SYMBOL_GPL(nvdimm_region_notify); +long nvdimm_clear_poison(struct device *dev, phys_addr_t phys, + unsigned int len) +{ + struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev); + struct nvdimm_bus_descriptor *nd_desc; + struct nd_cmd_clear_error clear_err; + struct nd_cmd_ars_cap ars_cap; + u32 clear_err_unit, mask; + int cmd_rc, rc; + + if (!nvdimm_bus) + return -ENXIO; + + nd_desc = nvdimm_bus->nd_desc; + if (!nd_desc->ndctl) + return -ENXIO; + + memset(&ars_cap, 0, sizeof(ars_cap)); + ars_cap.address = phys; + ars_cap.length = len; + rc = nd_desc->ndctl(nd_desc, NULL, ND_CMD_ARS_CAP, &ars_cap, + sizeof(ars_cap), &cmd_rc); + if (rc < 0) + return rc; + if (cmd_rc < 0) + return cmd_rc; + clear_err_unit = ars_cap.clear_err_unit; + if (!clear_err_unit || !is_power_of_2(clear_err_unit)) + return -ENXIO; + + mask = clear_err_unit - 1; + if ((phys | len) & mask) + return -ENXIO; + memset(&clear_err, 0, sizeof(clear_err)); + clear_err.address = phys; + clear_err.length = len; + rc = nd_desc->ndctl(nd_desc, NULL, ND_CMD_CLEAR_ERROR, &clear_err, + sizeof(clear_err), &cmd_rc); + if (rc < 0) + return rc; + if (cmd_rc < 0) + return cmd_rc; + return clear_err.cleared; +} +EXPORT_SYMBOL_GPL(nvdimm_clear_poison); + static struct bus_type nvdimm_bus_type = { .name = "nd", .uevent = nvdimm_bus_uevent, diff --git a/drivers/nvdimm/nd.h b/drivers/nvdimm/nd.h index 78b82f6dd191..1799bd97a9ce 100644 --- a/drivers/nvdimm/nd.h +++ b/drivers/nvdimm/nd.h @@ -186,6 +186,8 @@ int nvdimm_init_nsarea(struct nvdimm_drvdata *ndd); int nvdimm_init_config_data(struct nvdimm_drvdata *ndd); int nvdimm_set_config_data(struct nvdimm_drvdata *ndd, size_t offset, void *buf, size_t len); +long nvdimm_clear_poison(struct device *dev, phys_addr_t phys, + unsigned int len); struct nd_btt *to_nd_btt(struct device *dev); struct nd_gen_sb { diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c index e7b86a7fca0a..adc387236fe7 100644 --- a/drivers/nvdimm/pmem.c +++ b/drivers/nvdimm/pmem.c @@ -62,17 +62,40 @@ static bool is_bad_pmem(struct badblocks *bb, sector_t sector, unsigned int len) return false; } +static void pmem_clear_poison(struct pmem_device *pmem, phys_addr_t offset, + unsigned int len) +{ + struct device *dev = disk_to_dev(pmem->pmem_disk); + sector_t sector; + long cleared; + + sector = (offset - pmem->data_offset) / 512; + cleared = nvdimm_clear_poison(dev, pmem->phys_addr + offset, len); + + if (cleared > 0 && cleared / 512) { + dev_dbg(dev, "%s: %llx clear %ld sector%s\n", + __func__, (unsigned long long) sector, + cleared / 512, cleared / 512 > 1 ? "s" : ""); + badblocks_clear(&pmem->bb, sector, cleared / 512); + } + invalidate_pmem(pmem->virt_addr + offset, len); +} + static int pmem_do_bvec(struct pmem_device *pmem, struct page *page, unsigned int len, unsigned int off, int rw, sector_t sector) { int rc = 0; + bool bad_pmem = false; void *mem = kmap_atomic(page); phys_addr_t pmem_off = sector * 512 + pmem->data_offset; void __pmem *pmem_addr = pmem->virt_addr + pmem_off; + if (unlikely(is_bad_pmem(&pmem->bb, sector, len))) + bad_pmem = true; + if (rw == READ) { - if (unlikely(is_bad_pmem(&pmem->bb, sector, len))) + if (unlikely(bad_pmem)) rc = -EIO; else { memcpy_from_pmem(mem + off, pmem_addr, len); @@ -81,6 +104,10 @@ static int pmem_do_bvec(struct pmem_device *pmem, struct page *page, } else { flush_dcache_page(page); memcpy_to_pmem(pmem_addr, mem + off, len); + if (unlikely(bad_pmem)) { + pmem_clear_poison(pmem, pmem_off, len); + memcpy_to_pmem(pmem_addr, mem + off, len); + } } kunmap_atomic(mem); diff --git a/include/linux/pmem.h b/include/linux/pmem.h index 7c3d11a6b4ad..3ec5309e29f3 100644 --- a/include/linux/pmem.h +++ b/include/linux/pmem.h @@ -58,6 +58,11 @@ static inline void arch_wb_cache_pmem(void __pmem *addr, size_t size) { BUG(); } + +static inline void arch_invalidate_pmem(void __pmem *addr, size_t size) +{ + BUG(); +} #endif /* @@ -185,6 +190,20 @@ static inline void clear_pmem(void __pmem *addr, size_t size) default_clear_pmem(addr, size); } +/** + * invalidate_pmem - flush a pmem range from the cache hierarchy + * @addr: virtual start address + * @size: bytes to invalidate (internally aligned to cache line size) + * + * For platforms that support clearing poison this flushes any poisoned + * ranges out of the cache + */ +static inline void invalidate_pmem(void __pmem *addr, size_t size) +{ + if (arch_has_pmem_api()) + arch_invalidate_pmem(addr, size); +} + /** * wb_cache_pmem - write back processor cache for PMEM memory range * @addr: virtual start address -- 2.20.1