From 7d0ecc0bd83dc2b2f46087f955c9572073e45aca Mon Sep 17 00:00:00 2001 From: Davidlohr Bueso Date: Thu, 20 Feb 2025 14:02:34 -0800 Subject: [PATCH] cxl/pmem: Export dirty shutdown count via sysfs Similar to how the acpi_nfit driver exports Optane dirty shutdown count, introduce: /sys/bus/cxl/devices/nvdimm-bridge0/ndbusX/nmemY/cxl/dirty_shutdown Under the conditions that 1) dirty shutdown can be set, 2) Device GPF DVSEC exists, and 3) the count itself can be retrieved. Suggested-by: Dan Williams Signed-off-by: Davidlohr Bueso Reviewed-by: Dave Jiang Reviewed-by: Ira Weiny Reviewed-by: Jonathan Cameron Link: https://patch.msgid.link/20250220220235.276831-4-dave@stgolabs.net Signed-off-by: Dave Jiang --- Documentation/ABI/testing/sysfs-bus-cxl | 12 +++ Documentation/driver-api/cxl/maturity-map.rst | 2 +- drivers/cxl/core/mbox.c | 21 +++++ drivers/cxl/cxl.h | 1 + drivers/cxl/cxlmem.h | 13 ++++ drivers/cxl/pmem.c | 77 +++++++++++++++++-- 6 files changed, 117 insertions(+), 9 deletions(-) diff --git a/Documentation/ABI/testing/sysfs-bus-cxl b/Documentation/ABI/testing/sysfs-bus-cxl index 3f5627a1210a..a7491d214098 100644 --- a/Documentation/ABI/testing/sysfs-bus-cxl +++ b/Documentation/ABI/testing/sysfs-bus-cxl @@ -586,3 +586,15 @@ Description: See Documentation/ABI/stable/sysfs-devices-node. access0 provides the number to the closest initiator and access1 provides the number to the closest CPU. + + +What: /sys/bus/cxl/devices/nvdimm-bridge0/ndbusX/nmemY/cxl/dirty_shutdown +Date: Feb, 2025 +KernelVersion: v6.15 +Contact: linux-cxl@vger.kernel.org +Description: + (RO) The device dirty shutdown count value, which is the number + of times the device could have incurred in potential data loss. + The count is persistent across power loss and wraps back to 0 + upon overflow. If this file is not present, the device does not + have the necessary support for dirty tracking. diff --git a/Documentation/driver-api/cxl/maturity-map.rst b/Documentation/driver-api/cxl/maturity-map.rst index 99dd2c841e69..a2288f9df658 100644 --- a/Documentation/driver-api/cxl/maturity-map.rst +++ b/Documentation/driver-api/cxl/maturity-map.rst @@ -130,7 +130,7 @@ Mailbox commands * [0] Switch CCI * [3] Timestamp * [1] PMEM labels -* [1] PMEM GPF / Dirty Shutdown +* [3] PMEM GPF / Dirty Shutdown * [0] Scan Media PMU diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c index 3687c8da1927..ec7b70ae5c06 100644 --- a/drivers/cxl/core/mbox.c +++ b/drivers/cxl/core/mbox.c @@ -1308,6 +1308,27 @@ int cxl_mem_create_range_info(struct cxl_memdev_state *mds) } EXPORT_SYMBOL_NS_GPL(cxl_mem_create_range_info, "CXL"); +int cxl_get_dirty_count(struct cxl_memdev_state *mds, u32 *count) +{ + struct cxl_mailbox *cxl_mbox = &mds->cxlds.cxl_mbox; + struct cxl_mbox_get_health_info_out hi; + struct cxl_mbox_cmd mbox_cmd; + int rc; + + mbox_cmd = (struct cxl_mbox_cmd) { + .opcode = CXL_MBOX_OP_GET_HEALTH_INFO, + .size_out = sizeof(hi), + .payload_out = &hi, + }; + + rc = cxl_internal_send_cmd(cxl_mbox, &mbox_cmd); + if (!rc) + *count = le32_to_cpu(hi.dirty_shutdown_cnt); + + return rc; +} +EXPORT_SYMBOL_NS_GPL(cxl_get_dirty_count, "CXL"); + int cxl_arm_dirty_shutdown(struct cxl_memdev_state *mds) { struct cxl_mailbox *cxl_mbox = &mds->cxlds.cxl_mbox; diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h index fc4edd5536b9..b265347cedce 100644 --- a/drivers/cxl/cxl.h +++ b/drivers/cxl/cxl.h @@ -563,6 +563,7 @@ struct cxl_nvdimm { struct device dev; struct cxl_memdev *cxlmd; u8 dev_id[CXL_DEV_ID_LEN]; /* for nvdimm, string of 'serial' */ + u64 dirty_shutdowns; }; struct cxl_pmem_region_mapping { diff --git a/drivers/cxl/cxlmem.h b/drivers/cxl/cxlmem.h index 0e2df6904454..236e418d26f4 100644 --- a/drivers/cxl/cxlmem.h +++ b/drivers/cxl/cxlmem.h @@ -693,6 +693,18 @@ struct cxl_mbox_set_partition_info { #define CXL_SET_PARTITION_IMMEDIATE_FLAG BIT(0) +/* Get Health Info Output Payload CXL 3.2 Spec 8.2.10.9.3.1 Table 8-148 */ +struct cxl_mbox_get_health_info_out { + u8 health_status; + u8 media_status; + u8 additional_status; + u8 life_used; + __le16 device_temperature; + __le32 dirty_shutdown_cnt; + __le32 corrected_volatile_error_cnt; + __le32 corrected_persistent_error_cnt; +} __packed; + /* Set Shutdown State Input Payload CXL 3.2 Spec 8.2.10.9.3.5 Table 8-152 */ struct cxl_mbox_set_shutdown_state_in { u8 state; @@ -834,6 +846,7 @@ void cxl_event_trace_record(const struct cxl_memdev *cxlmd, enum cxl_event_log_type type, enum cxl_event_type event_type, const uuid_t *uuid, union cxl_event *evt); +int cxl_get_dirty_count(struct cxl_memdev_state *mds, u32 *count); int cxl_arm_dirty_shutdown(struct cxl_memdev_state *mds); int cxl_set_timestamp(struct cxl_memdev_state *mds); int cxl_poison_state_init(struct cxl_memdev_state *mds); diff --git a/drivers/cxl/pmem.c b/drivers/cxl/pmem.c index 6b284962592f..81db5d629049 100644 --- a/drivers/cxl/pmem.c +++ b/drivers/cxl/pmem.c @@ -42,15 +42,44 @@ static ssize_t id_show(struct device *dev, struct device_attribute *attr, char * } static DEVICE_ATTR_RO(id); +static ssize_t dirty_shutdown_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct nvdimm *nvdimm = to_nvdimm(dev); + struct cxl_nvdimm *cxl_nvd = nvdimm_provider_data(nvdimm); + + return sysfs_emit(buf, "%llu\n", cxl_nvd->dirty_shutdowns); +} +static DEVICE_ATTR_RO(dirty_shutdown); + static struct attribute *cxl_dimm_attributes[] = { &dev_attr_id.attr, &dev_attr_provider.attr, + &dev_attr_dirty_shutdown.attr, NULL }; +#define CXL_INVALID_DIRTY_SHUTDOWN_COUNT ULLONG_MAX +static umode_t cxl_dimm_visible(struct kobject *kobj, + struct attribute *a, int n) +{ + if (a == &dev_attr_dirty_shutdown.attr) { + struct device *dev = kobj_to_dev(kobj); + struct nvdimm *nvdimm = to_nvdimm(dev); + struct cxl_nvdimm *cxl_nvd = nvdimm_provider_data(nvdimm); + + if (cxl_nvd->dirty_shutdowns == + CXL_INVALID_DIRTY_SHUTDOWN_COUNT) + return 0; + } + + return a->mode; +} + static const struct attribute_group cxl_dimm_attribute_group = { .name = "cxl", .attrs = cxl_dimm_attributes, + .is_visible = cxl_dimm_visible }; static const struct attribute_group *cxl_dimm_attribute_groups[] = { @@ -58,6 +87,38 @@ static const struct attribute_group *cxl_dimm_attribute_groups[] = { NULL }; +static void cxl_nvdimm_arm_dirty_shutdown_tracking(struct cxl_nvdimm *cxl_nvd) +{ + struct cxl_memdev *cxlmd = cxl_nvd->cxlmd; + struct cxl_dev_state *cxlds = cxlmd->cxlds; + struct cxl_memdev_state *mds = to_cxl_memdev_state(cxlds); + struct device *dev = &cxl_nvd->dev; + u32 count; + + /* + * Dirty tracking is enabled and exposed to the user, only when: + * - dirty shutdown on the device can be set, and, + * - the device has a Device GPF DVSEC (albeit unused), and, + * - the Get Health Info cmd can retrieve the device's dirty count. + */ + cxl_nvd->dirty_shutdowns = CXL_INVALID_DIRTY_SHUTDOWN_COUNT; + + if (cxl_arm_dirty_shutdown(mds)) { + dev_warn(dev, "GPF: could not set dirty shutdown state\n"); + return; + } + + if (!cxl_gpf_get_dvsec(cxlds->dev, false)) + return; + + if (cxl_get_dirty_count(mds, &count)) { + dev_warn(dev, "GPF: could not retrieve dirty count\n"); + return; + } + + cxl_nvd->dirty_shutdowns = count; +} + static int cxl_nvdimm_probe(struct device *dev) { struct cxl_nvdimm *cxl_nvd = to_cxl_nvdimm(dev); @@ -78,20 +139,20 @@ static int cxl_nvdimm_probe(struct device *dev) set_bit(ND_CMD_GET_CONFIG_SIZE, &cmd_mask); set_bit(ND_CMD_GET_CONFIG_DATA, &cmd_mask); set_bit(ND_CMD_SET_CONFIG_DATA, &cmd_mask); - nvdimm = __nvdimm_create(cxl_nvb->nvdimm_bus, cxl_nvd, - cxl_dimm_attribute_groups, flags, - cmd_mask, 0, NULL, cxl_nvd->dev_id, - cxl_security_ops, NULL); - if (!nvdimm) - return -ENOMEM; /* * Set dirty shutdown now, with the expectation that the device * clear it upon a successful GPF flow. The exception to this * is upon Viral detection, per CXL 3.2 section 12.4.2. */ - if (cxl_arm_dirty_shutdown(mds)) - dev_warn(dev, "GPF: could not dirty shutdown state\n"); + cxl_nvdimm_arm_dirty_shutdown_tracking(cxl_nvd); + + nvdimm = __nvdimm_create(cxl_nvb->nvdimm_bus, cxl_nvd, + cxl_dimm_attribute_groups, flags, + cmd_mask, 0, NULL, cxl_nvd->dev_id, + cxl_security_ops, NULL); + if (!nvdimm) + return -ENOMEM; dev_set_drvdata(dev, nvdimm); return devm_add_action_or_reset(dev, unregister_nvdimm, nvdimm); -- 2.50.1