[PATCH 1/3] nfit, libnvdimm: clear poison command support

From: Dan Williams
Date: Tue Mar 08 2016 - 17:48:09 EST


Add the boiler-plate for a 'clear error' command based on section
9.20.7.6 "Function Index 4 - Clear Uncorrectable Error" from the ACPI
6.1 specification, and add a reference implementation in nfit_test.

Cc: Vishal Verma <vishal.l.verma@xxxxxxxxx>
Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
---
drivers/acpi/nfit.c | 12 +++++++++++-
drivers/nvdimm/bus.c | 19 +++++++++++++++++++
include/uapi/linux/ndctl.h | 13 +++++++++++++
tools/testing/nvdimm/test/nfit.c | 29 +++++++++++++++++++++++++++++
4 files changed, 72 insertions(+), 1 deletion(-)

diff --git a/drivers/acpi/nfit.c b/drivers/acpi/nfit.c
index 0def4ebf5d43..c067d7414007 100644
--- a/drivers/acpi/nfit.c
+++ b/drivers/acpi/nfit.c
@@ -87,6 +87,7 @@ static struct acpi_device *to_acpi_dev(struct acpi_nfit_desc *acpi_desc)

static int xlat_status(void *buf, unsigned int cmd)
{
+ struct nd_cmd_clear_error *clear_err;
struct nd_cmd_ars_status *ars_status;
struct nd_cmd_ars_start *ars_start;
struct nd_cmd_ars_cap *ars_cap;
@@ -149,6 +150,15 @@ static int xlat_status(void *buf, unsigned int cmd)
if (ars_status->status >> 16)
return -EIO;
break;
+ case ND_CMD_CLEAR_ERROR:
+ clear_err = buf;
+ if (clear_err->status & 0xffff)
+ return -EIO;
+ if (!clear_err->cleared)
+ return -EIO;
+ if (clear_err->length > clear_err->cleared)
+ return clear_err->cleared;
+ break;
default:
break;
}
@@ -1002,7 +1012,7 @@ static void acpi_nfit_init_dsms(struct acpi_nfit_desc *acpi_desc)
if (!adev)
return;

- for (i = ND_CMD_ARS_CAP; i <= ND_CMD_ARS_STATUS; i++)
+ for (i = ND_CMD_ARS_CAP; i <= ND_CMD_CLEAR_ERROR; i++)
if (acpi_check_dsm(adev->handle, uuid, 1, 1ULL << i))
set_bit(i, &nd_desc->dsm_mask);
}
diff --git a/drivers/nvdimm/bus.c b/drivers/nvdimm/bus.c
index 2e9ac22595ec..cb6fd64b13e3 100644
--- a/drivers/nvdimm/bus.c
+++ b/drivers/nvdimm/bus.c
@@ -421,6 +421,12 @@ static const struct nd_cmd_desc __nd_cmd_bus_descs[] = {
.out_num = 3,
.out_sizes = { 4, 4, UINT_MAX, },
},
+ [ND_CMD_CLEAR_ERROR] = {
+ .in_num = 2,
+ .in_sizes = { 8, 8, },
+ .out_num = 3,
+ .out_sizes = { 4, 4, 8, },
+ },
};

const struct nd_cmd_desc *nd_cmd_bus_desc(int cmd)
@@ -489,6 +495,13 @@ void wait_nvdimm_bus_probe_idle(struct device *dev)
} while (true);
}

+static int pmem_active(struct device *dev, void *data)
+{
+ if (is_nd_pmem(dev) && dev->driver)
+ return -EBUSY;
+ return 0;
+}
+
/* set_config requires an idle interleave set */
static int nd_cmd_clear_to_send(struct nvdimm_bus *nvdimm_bus,
struct nvdimm *nvdimm, unsigned int cmd)
@@ -503,6 +516,11 @@ static int nd_cmd_clear_to_send(struct nvdimm_bus *nvdimm_bus,
return rc;
}

+ /* require clear error to go through the pmem driver */
+ if (!nvdimm && cmd == ND_CMD_CLEAR_ERROR)
+ return device_for_each_child(&nvdimm_bus->dev, NULL,
+ pmem_active);
+
if (!nvdimm || cmd != ND_CMD_SET_CONFIG_DATA)
return 0;

@@ -551,6 +569,7 @@ static int __nd_ioctl(struct nvdimm_bus *nvdimm_bus, struct nvdimm *nvdimm,
case ND_CMD_VENDOR:
case ND_CMD_SET_CONFIG_DATA:
case ND_CMD_ARS_START:
+ case ND_CMD_CLEAR_ERROR:
dev_dbg(&nvdimm_bus->dev, "'%s' command while read-only.\n",
nvdimm ? nvdimm_cmd_name(cmd)
: nvdimm_bus_cmd_name(cmd));
diff --git a/include/uapi/linux/ndctl.h b/include/uapi/linux/ndctl.h
index cc68b92124d4..0f001c571cdd 100644
--- a/include/uapi/linux/ndctl.h
+++ b/include/uapi/linux/ndctl.h
@@ -98,6 +98,14 @@ struct nd_cmd_ars_status {
} __packed records[0];
} __packed;

+struct nd_cmd_clear_error {
+ __u64 address;
+ __u64 length;
+ __u32 status;
+ __u8 reserved[4];
+ __u64 cleared;
+} __packed;
+
enum {
ND_CMD_IMPLEMENTED = 0,

@@ -105,6 +113,7 @@ enum {
ND_CMD_ARS_CAP = 1,
ND_CMD_ARS_START = 2,
ND_CMD_ARS_STATUS = 3,
+ ND_CMD_CLEAR_ERROR = 4,

/* per-dimm commands */
ND_CMD_SMART = 1,
@@ -129,6 +138,7 @@ static inline const char *nvdimm_bus_cmd_name(unsigned cmd)
[ND_CMD_ARS_CAP] = "ars_cap",
[ND_CMD_ARS_START] = "ars_start",
[ND_CMD_ARS_STATUS] = "ars_status",
+ [ND_CMD_CLEAR_ERROR] = "clear_error",
};

if (cmd < ARRAY_SIZE(names) && names[cmd])
@@ -187,6 +197,9 @@ static inline const char *nvdimm_cmd_name(unsigned cmd)
#define ND_IOCTL_ARS_STATUS _IOWR(ND_IOCTL, ND_CMD_ARS_STATUS,\
struct nd_cmd_ars_status)

+#define ND_IOCTL_CLEAR_ERROR _IOWR(ND_IOCTL, ND_CMD_CLEAR_ERROR,\
+ struct nd_cmd_ars_status)
+
#define ND_DEVICE_DIMM 1 /* nd_dimm: container for "config data" */
#define ND_DEVICE_REGION_PMEM 2 /* nd_region: (parent of PMEM namespaces) */
#define ND_DEVICE_REGION_BLK 3 /* nd_region: (parent of BLK namespaces) */
diff --git a/tools/testing/nvdimm/test/nfit.c b/tools/testing/nvdimm/test/nfit.c
index 1555c09efba1..3187322eeed7 100644
--- a/tools/testing/nvdimm/test/nfit.c
+++ b/tools/testing/nvdimm/test/nfit.c
@@ -223,6 +223,7 @@ static int nfit_test_cmd_set_config_data(struct nd_cmd_set_config_hdr *nd_cmd,
}

#define NFIT_TEST_ARS_RECORDS 4
+#define NFIT_TEST_CLEAR_ERR_UNIT 256

static int nfit_test_cmd_ars_cap(struct nd_cmd_ars_cap *nd_cmd,
unsigned int buf_len)
@@ -233,6 +234,7 @@ static int nfit_test_cmd_ars_cap(struct nd_cmd_ars_cap *nd_cmd,
nd_cmd->max_ars_out = sizeof(struct nd_cmd_ars_status)
+ NFIT_TEST_ARS_RECORDS * sizeof(struct nd_ars_record);
nd_cmd->status = (ND_ARS_PERSISTENT | ND_ARS_VOLATILE) << 16;
+ nd_cmd->clear_err_unit = NFIT_TEST_CLEAR_ERR_UNIT;

return 0;
}
@@ -306,6 +308,28 @@ static int nfit_test_cmd_ars_status(struct ars_state *ars_state,
return 0;
}

+static int nfit_test_cmd_clear_error(struct nd_cmd_clear_error *clear_err,
+ unsigned int buf_len, int *cmd_rc)
+{
+ const u64 mask = NFIT_TEST_CLEAR_ERR_UNIT - 1;
+ if (buf_len < sizeof(*clear_err))
+ return -EINVAL;
+
+ if ((clear_err->address & mask) || (clear_err->length & mask))
+ return -EINVAL;
+
+ /*
+ * Report 'all clear' success for all commands even though a new
+ * scrub will find errors again. This is enough to have the
+ * error removed from the 'badblocks' tracking in the pmem
+ * driver.
+ */
+ clear_err->status = 0;
+ clear_err->cleared = clear_err->length;
+ *cmd_rc = 0;
+ return 0;
+}
+
static int nfit_test_ctl(struct nvdimm_bus_descriptor *nd_desc,
struct nvdimm *nvdimm, unsigned int cmd, void *buf,
unsigned int buf_len, int *cmd_rc)
@@ -365,6 +389,9 @@ static int nfit_test_ctl(struct nvdimm_bus_descriptor *nd_desc,
rc = nfit_test_cmd_ars_status(ars_state, buf, buf_len,
cmd_rc);
break;
+ case ND_CMD_CLEAR_ERROR:
+ rc = nfit_test_cmd_clear_error(buf, buf_len, cmd_rc);
+ break;
default:
return -ENOTTY;
}
@@ -1230,6 +1257,7 @@ static void nfit_test0_setup(struct nfit_test *t)
set_bit(ND_CMD_ARS_CAP, &acpi_desc->bus_dsm_force_en);
set_bit(ND_CMD_ARS_START, &acpi_desc->bus_dsm_force_en);
set_bit(ND_CMD_ARS_STATUS, &acpi_desc->bus_dsm_force_en);
+ set_bit(ND_CMD_CLEAR_ERROR, &acpi_desc->bus_dsm_force_en);
}

static void nfit_test1_setup(struct nfit_test *t)
@@ -1290,6 +1318,7 @@ static void nfit_test1_setup(struct nfit_test *t)
set_bit(ND_CMD_ARS_CAP, &acpi_desc->bus_dsm_force_en);
set_bit(ND_CMD_ARS_START, &acpi_desc->bus_dsm_force_en);
set_bit(ND_CMD_ARS_STATUS, &acpi_desc->bus_dsm_force_en);
+ set_bit(ND_CMD_CLEAR_ERROR, &acpi_desc->bus_dsm_force_en);
}

static int nfit_test_blk_do_io(struct nd_blk_region *ndbr, resource_size_t dpa,