Patch adds performance stats reporting support for nvdimm. Added interface includes support for pmu register/unregister functions. A structure is added called nvdimm_pmu to be used for adding arch/platform specific data such as supported events and pmu event functions like event_init/add/read/del. User could use the standard perf tool to access perf events exposed via pmu.
Signed-off-by: Kajol Jain <kj...@linux.ibm.com> --- drivers/nvdimm/Makefile | 1 + drivers/nvdimm/nd_perf.c | 58 ++++++++++++++++++++++++++++++++++++++++ include/linux/nd.h | 35 ++++++++++++++++++++++++ 3 files changed, 94 insertions(+) create mode 100644 drivers/nvdimm/nd_perf.c diff --git a/drivers/nvdimm/Makefile b/drivers/nvdimm/Makefile index 29203f3d3069..25dba6095612 100644 --- a/drivers/nvdimm/Makefile +++ b/drivers/nvdimm/Makefile @@ -18,6 +18,7 @@ nd_e820-y := e820.o libnvdimm-y := core.o libnvdimm-y += bus.o libnvdimm-y += dimm_devs.o +libnvdimm-y += nd_perf.o libnvdimm-y += dimm.o libnvdimm-y += region_devs.o libnvdimm-y += region.o diff --git a/drivers/nvdimm/nd_perf.c b/drivers/nvdimm/nd_perf.c new file mode 100644 index 000000000000..96280c1ff799 --- /dev/null +++ b/drivers/nvdimm/nd_perf.c @@ -0,0 +1,58 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * nd_perf.c: NVDIMM Device Performance Monitoring Unit support + * + * Perf interface to expose nvdimm performance stats. + * + * Copyright (C) 2021 IBM Corporation + */ + +#define pr_fmt(fmt) "nvdimm_pmu: " fmt + +#include <linux/nd.h> + +int register_nvdimm_pmu(struct nvdimm_pmu *nd_pmu, struct platform_device *pdev) +{ + int rc; + + if (!nd_pmu || !pdev) + return -EINVAL; + + /* event functions like add/del/read/event_init should not be NULL */ + if (WARN_ON_ONCE(!(nd_pmu->event_init && nd_pmu->add && nd_pmu->del && nd_pmu->read))) + return -EINVAL; + + nd_pmu->pmu.task_ctx_nr = perf_invalid_context; + nd_pmu->pmu.name = nd_pmu->name; + nd_pmu->pmu.event_init = nd_pmu->event_init; + nd_pmu->pmu.add = nd_pmu->add; + nd_pmu->pmu.del = nd_pmu->del; + nd_pmu->pmu.read = nd_pmu->read; + + nd_pmu->pmu.attr_groups = nd_pmu->attr_groups; + nd_pmu->pmu.capabilities = PERF_PMU_CAP_NO_INTERRUPT | + PERF_PMU_CAP_NO_EXCLUDE; + + /* + * Add platform_device->dev pointer to nvdimm_pmu to access + * device data in events functions. + */ + nd_pmu->dev = &pdev->dev; + + rc = perf_pmu_register(&nd_pmu->pmu, nd_pmu->name, -1); + if (rc) + return rc; + + pr_info("%s NVDIMM performance monitor support registered\n", + nd_pmu->name); + + return 0; +} +EXPORT_SYMBOL_GPL(register_nvdimm_pmu); + +void unregister_nvdimm_pmu(struct pmu *nd_pmu) +{ + /* handle freeing of memory in arch specific code */ + perf_pmu_unregister(nd_pmu); +} +EXPORT_SYMBOL_GPL(unregister_nvdimm_pmu); diff --git a/include/linux/nd.h b/include/linux/nd.h index ee9ad76afbba..a0e0619256be 100644 --- a/include/linux/nd.h +++ b/include/linux/nd.h @@ -8,6 +8,8 @@ #include <linux/ndctl.h> #include <linux/device.h> #include <linux/badblocks.h> +#include <linux/platform_device.h> +#include <linux/perf_event.h> enum nvdimm_event { NVDIMM_REVALIDATE_POISON, @@ -23,6 +25,39 @@ enum nvdimm_claim_class { NVDIMM_CCLASS_UNKNOWN, }; +/* Event attribute array index */ +#define NVDIMM_PMU_FORMAT_ATTR 0 +#define NVDIMM_PMU_EVENT_ATTR 1 +#define NVDIMM_PMU_NULL_ATTR 2 + +/** + * struct nvdimm_pmu - data structure for nvdimm perf driver + * + * @name: name of the nvdimm pmu device. + * @pmu: pmu data structure for nvdimm performance stats. + * @dev: nvdimm device pointer. + * @functions(event_init/add/del/read): platform specific pmu functions. + * @attr_groups: data structure for events and formats. + */ +struct nvdimm_pmu { + const char *name; + struct pmu pmu; + struct device *dev; + int (*event_init)(struct perf_event *event); + int (*add)(struct perf_event *event, int flags); + void (*del)(struct perf_event *event, int flags); + void (*read)(struct perf_event *event); + /* + * Attribute groups for the nvdimm pmu. Index 0 used for + * format attribute, index 1 used for event attribute and + * index 2 kept as NULL. + */ + const struct attribute_group *attr_groups[3]; +}; + +int register_nvdimm_pmu(struct nvdimm_pmu *nvdimm, struct platform_device *pdev); +void unregister_nvdimm_pmu(struct pmu *pmu); + struct nd_device_driver { struct device_driver drv; unsigned long type; -- 2.27.0