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Date: Tue, 08 Mar 2016 14:47:29 -0800
From: Dan Williams <dan.j.williams@...el.com>
To: linux-nvdimm@...ts.01.org
Cc: Vishal Verma <vishal.l.verma@...el.com>,
Ross Zwisler <ross.zwisler@...ux.intel.com>, x86@...nel.org,
linux-kernel@...r.kernel.org, linux-acpi@...r.kernel.org
Subject: [PATCH 3/3] 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: <x86@...nel.org>
Cc: Vishal Verma <vishal.l.verma@...el.com>
Cc: Ross Zwisler <ross.zwisler@...ux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@...el.com>
---
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
/*
@@ -186,6 +191,20 @@ static inline void clear_pmem(void __pmem *addr, size_t 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
* @size: number of bytes to write back
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