From 39a846db1d574a498511ffccd75223a35cdcb059 Mon Sep 17 00:00:00 2001 From: Anju T Sudhakar Date: Wed, 19 Jul 2017 03:06:35 +0530 Subject: [PATCH] powerpc/perf: Add core IMC PMU support Add support to register Core In-Memory Collection PMU counters. Patch adds core IMC specific data structures, along with memory init functions and CPU hotplug support. Signed-off-by: Anju T Sudhakar Signed-off-by: Hemant Kumar Signed-off-by: Madhavan Srinivasan Signed-off-by: Michael Ellerman --- arch/powerpc/perf/imc-pmu.c | 303 +++++++++++++++++++++++++++++++++++- include/linux/cpuhotplug.h | 1 + 2 files changed, 300 insertions(+), 4 deletions(-) diff --git a/arch/powerpc/perf/imc-pmu.c b/arch/powerpc/perf/imc-pmu.c index 4543faa1bb0d..482f8d6d5e65 100644 --- a/arch/powerpc/perf/imc-pmu.c +++ b/arch/powerpc/perf/imc-pmu.c @@ -31,6 +31,12 @@ static cpumask_t nest_imc_cpumask; struct imc_pmu_ref *nest_imc_refc; static int nest_pmus; +/* Core IMC data structures and variables */ + +static cpumask_t core_imc_cpumask; +struct imc_pmu_ref *core_imc_refc; +static struct imc_pmu *core_imc_pmu; + struct imc_pmu *imc_event_to_pmu(struct perf_event *event) { return container_of(event->pmu, struct imc_pmu, pmu); @@ -62,11 +68,13 @@ static ssize_t imc_pmu_cpumask_get_attr(struct device *dev, struct imc_pmu *imc_pmu = container_of(pmu, struct imc_pmu, pmu); cpumask_t *active_mask; - /* Subsequenct patch will add more pmu types here */ switch(imc_pmu->domain){ case IMC_DOMAIN_NEST: active_mask = &nest_imc_cpumask; break; + case IMC_DOMAIN_CORE: + active_mask = &core_imc_cpumask; + break; default: return 0; } @@ -486,6 +494,240 @@ static int nest_imc_event_init(struct perf_event *event) return 0; } +/* + * core_imc_mem_init : Initializes memory for the current core. + * + * Uses alloc_pages_node() and uses the returned address as an argument to + * an opal call to configure the pdbar. The address sent as an argument is + * converted to physical address before the opal call is made. This is the + * base address at which the core imc counters are populated. + */ +static int core_imc_mem_init(int cpu, int size) +{ + int phys_id, rc = 0, core_id = (cpu / threads_per_core); + struct imc_mem_info *mem_info; + + /* + * alloc_pages_node() will allocate memory for core in the + * local node only. + */ + phys_id = topology_physical_package_id(cpu); + mem_info = &core_imc_pmu->mem_info[core_id]; + mem_info->id = core_id; + + /* We need only vbase for core counters */ + mem_info->vbase = page_address(alloc_pages_node(phys_id, + GFP_KERNEL | __GFP_ZERO | __GFP_THISNODE, + get_order(size))); + if (!mem_info->vbase) + return -ENOMEM; + + /* Init the mutex */ + core_imc_refc[core_id].id = core_id; + mutex_init(&core_imc_refc[core_id].lock); + + rc = opal_imc_counters_init(OPAL_IMC_COUNTERS_CORE, + __pa((void *)mem_info->vbase), + get_hard_smp_processor_id(cpu)); + if (rc) { + free_pages((u64)mem_info->vbase, get_order(size)); + mem_info->vbase = NULL; + } + + return rc; +} + +static bool is_core_imc_mem_inited(int cpu) +{ + struct imc_mem_info *mem_info; + int core_id = (cpu / threads_per_core); + + mem_info = &core_imc_pmu->mem_info[core_id]; + if (!mem_info->vbase) + return false; + + return true; +} + +static int ppc_core_imc_cpu_online(unsigned int cpu) +{ + const struct cpumask *l_cpumask; + static struct cpumask tmp_mask; + int ret = 0; + + /* Get the cpumask for this core */ + l_cpumask = cpu_sibling_mask(cpu); + + /* If a cpu for this core is already set, then, don't do anything */ + if (cpumask_and(&tmp_mask, l_cpumask, &core_imc_cpumask)) + return 0; + + if (!is_core_imc_mem_inited(cpu)) { + ret = core_imc_mem_init(cpu, core_imc_pmu->counter_mem_size); + if (ret) { + pr_info("core_imc memory allocation for cpu %d failed\n", cpu); + return ret; + } + } + + /* set the cpu in the mask */ + cpumask_set_cpu(cpu, &core_imc_cpumask); + return 0; +} + +static int ppc_core_imc_cpu_offline(unsigned int cpu) +{ + unsigned int ncpu, core_id; + struct imc_pmu_ref *ref; + + /* + * clear this cpu out of the mask, if not present in the mask, + * don't bother doing anything. + */ + if (!cpumask_test_and_clear_cpu(cpu, &core_imc_cpumask)) + return 0; + + /* Find any online cpu in that core except the current "cpu" */ + ncpu = cpumask_any_but(cpu_sibling_mask(cpu), cpu); + + if (ncpu >= 0 && ncpu < nr_cpu_ids) { + cpumask_set_cpu(ncpu, &core_imc_cpumask); + perf_pmu_migrate_context(&core_imc_pmu->pmu, cpu, ncpu); + } else { + /* + * If this is the last cpu in this core then, skip taking refernce + * count mutex lock for this core and directly zero "refc" for + * this core. + */ + opal_imc_counters_stop(OPAL_IMC_COUNTERS_CORE, + get_hard_smp_processor_id(cpu)); + core_id = cpu / threads_per_core; + ref = &core_imc_refc[core_id]; + if (!ref) + return -EINVAL; + + ref->refc = 0; + } + return 0; +} + +static int core_imc_pmu_cpumask_init(void) +{ + return cpuhp_setup_state(CPUHP_AP_PERF_POWERPC_CORE_IMC_ONLINE, + "perf/powerpc/imc_core:online", + ppc_core_imc_cpu_online, + ppc_core_imc_cpu_offline); +} + +static void core_imc_counters_release(struct perf_event *event) +{ + int rc, core_id; + struct imc_pmu_ref *ref; + + if (event->cpu < 0) + return; + /* + * See if we need to disable the IMC PMU. + * If no events are currently in use, then we have to take a + * mutex to ensure that we don't race with another task doing + * enable or disable the core counters. + */ + core_id = event->cpu / threads_per_core; + + /* Take the mutex lock and decrement the refernce count for this core */ + ref = &core_imc_refc[core_id]; + if (!ref) + return; + + mutex_lock(&ref->lock); + ref->refc--; + if (ref->refc == 0) { + rc = opal_imc_counters_stop(OPAL_IMC_COUNTERS_CORE, + get_hard_smp_processor_id(event->cpu)); + if (rc) { + mutex_unlock(&ref->lock); + pr_err("IMC: Unable to stop the counters for core %d\n", core_id); + return; + } + } else if (ref->refc < 0) { + WARN(1, "core-imc: Invalid event reference count\n"); + ref->refc = 0; + } + mutex_unlock(&ref->lock); +} + +static int core_imc_event_init(struct perf_event *event) +{ + int core_id, rc; + u64 config = event->attr.config; + struct imc_mem_info *pcmi; + struct imc_pmu *pmu; + struct imc_pmu_ref *ref; + + if (event->attr.type != event->pmu->type) + return -ENOENT; + + /* Sampling not supported */ + if (event->hw.sample_period) + return -EINVAL; + + /* unsupported modes and filters */ + if (event->attr.exclude_user || + event->attr.exclude_kernel || + event->attr.exclude_hv || + event->attr.exclude_idle || + event->attr.exclude_host || + event->attr.exclude_guest) + return -EINVAL; + + if (event->cpu < 0) + return -EINVAL; + + event->hw.idx = -1; + pmu = imc_event_to_pmu(event); + + /* Sanity check for config (event offset) */ + if (((config & IMC_EVENT_OFFSET_MASK) > pmu->counter_mem_size)) + return -EINVAL; + + if (!is_core_imc_mem_inited(event->cpu)) + return -ENODEV; + + core_id = event->cpu / threads_per_core; + pcmi = &core_imc_pmu->mem_info[core_id]; + if ((!pcmi->vbase)) + return -ENODEV; + + /* Get the core_imc mutex for this core */ + ref = &core_imc_refc[core_id]; + if (!ref) + return -EINVAL; + + /* + * Core pmu units are enabled only when it is used. + * See if this is triggered for the first time. + * If yes, take the mutex lock and enable the core counters. + * If not, just increment the count in core_imc_refc struct. + */ + mutex_lock(&ref->lock); + if (ref->refc == 0) { + rc = opal_imc_counters_start(OPAL_IMC_COUNTERS_CORE, + get_hard_smp_processor_id(event->cpu)); + if (rc) { + mutex_unlock(&ref->lock); + pr_err("core-imc: Unable to start the counters for core %d\n", + core_id); + return rc; + } + } + ++ref->refc; + mutex_unlock(&ref->lock); + + event->hw.event_base = (u64)pcmi->vbase + (config & IMC_EVENT_OFFSET_MASK); + event->destroy = core_imc_counters_release; + return 0; +} + static u64 * get_event_base_addr(struct perf_event *event) { /* @@ -564,12 +806,15 @@ static int update_pmu_ops(struct imc_pmu *pmu) pmu->pmu.attr_groups = pmu->attr_groups; pmu->attr_groups[IMC_FORMAT_ATTR] = &imc_format_group; - /* Subsequenct patch will add more pmu types here */ switch (pmu->domain) { case IMC_DOMAIN_NEST: pmu->pmu.event_init = nest_imc_event_init; pmu->attr_groups[IMC_CPUMASK_ATTR] = &imc_pmu_cpumask_attr_group; break; + case IMC_DOMAIN_CORE: + pmu->pmu.event_init = core_imc_event_init; + pmu->attr_groups[IMC_CPUMASK_ATTR] = &imc_pmu_cpumask_attr_group; + break; default: break; } @@ -621,6 +866,22 @@ static int init_nest_pmu_ref(void) return 0; } +static void cleanup_all_core_imc_memory(void) +{ + int i, nr_cores = num_present_cpus() / threads_per_core; + struct imc_mem_info *ptr = core_imc_pmu->mem_info; + int size = core_imc_pmu->counter_mem_size; + + /* mem_info will never be NULL */ + for (i = 0; i < nr_cores; i++) { + if (ptr[i].vbase) + free_pages((u64)ptr->vbase, get_order(size)); + } + + kfree(ptr); + kfree(core_imc_refc); +} + /* * Common function to unregister cpu hotplug callback and * free the memory. @@ -641,6 +902,12 @@ static void imc_common_cpuhp_mem_free(struct imc_pmu *pmu_ptr) mutex_unlock(&nest_init_lock); } + /* Free core_imc memory */ + if (pmu_ptr->domain == IMC_DOMAIN_CORE) { + cpuhp_remove_state(CPUHP_AP_PERF_POWERPC_CORE_IMC_ONLINE); + cleanup_all_core_imc_memory(); + } + /* Only free the attr_groups which are dynamically allocated */ kfree(pmu_ptr->attr_groups[IMC_EVENT_ATTR]->attrs); kfree(pmu_ptr->attr_groups[IMC_EVENT_ATTR]); @@ -656,11 +923,11 @@ static int imc_mem_init(struct imc_pmu *pmu_ptr, struct device_node *parent, int pmu_index) { const char *s; + int nr_cores; if (of_property_read_string(parent, "name", &s)) return -ENODEV; - /* Subsequenct patch will add more pmu types here */ switch (pmu_ptr->domain) { case IMC_DOMAIN_NEST: /* Update the pmu name */ @@ -671,6 +938,27 @@ static int imc_mem_init(struct imc_pmu *pmu_ptr, struct device_node *parent, /* Needed for hotplug/migration */ per_nest_pmu_arr[pmu_index] = pmu_ptr; break; + case IMC_DOMAIN_CORE: + /* Update the pmu name */ + pmu_ptr->pmu.name = kasprintf(GFP_KERNEL, "%s%s", s, "_imc"); + if (!pmu_ptr->pmu.name) + return -ENOMEM; + + nr_cores = num_present_cpus() / threads_per_core; + pmu_ptr->mem_info = kcalloc(nr_cores, sizeof(struct imc_mem_info), + GFP_KERNEL); + + if (!pmu_ptr->mem_info) + return -ENOMEM; + + core_imc_refc = kcalloc(nr_cores, sizeof(struct imc_pmu_ref), + GFP_KERNEL); + + if (!core_imc_refc) + return -ENOMEM; + + core_imc_pmu = pmu_ptr; + break; default: return -EINVAL; } @@ -696,7 +984,6 @@ int init_imc_pmu(struct device_node *parent, struct imc_pmu *pmu_ptr, int pmu_id if (ret) goto err_free; - /* Subsequenct patch will add more pmu types here */ switch (pmu_ptr->domain) { case IMC_DOMAIN_NEST: /* @@ -721,6 +1008,14 @@ int init_imc_pmu(struct device_node *parent, struct imc_pmu *pmu_ptr, int pmu_id } nest_pmus++; mutex_unlock(&nest_init_lock); + break; + case IMC_DOMAIN_CORE: + ret = core_imc_pmu_cpumask_init(); + if (ret) { + cleanup_all_core_imc_memory(); + return ret; + } + break; default: return -1; /* Unknown domain */ diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h index 0853a14b1fa1..1be505db0090 100644 --- a/include/linux/cpuhotplug.h +++ b/include/linux/cpuhotplug.h @@ -140,6 +140,7 @@ enum cpuhp_state { CPUHP_AP_PERF_ARM_QCOM_L2_ONLINE, CPUHP_AP_PERF_ARM_QCOM_L3_ONLINE, CPUHP_AP_PERF_POWERPC_NEST_IMC_ONLINE, + CPUHP_AP_PERF_POWERPC_CORE_IMC_ONLINE, CPUHP_AP_WORKQUEUE_ONLINE, CPUHP_AP_RCUTREE_ONLINE, CPUHP_AP_ONLINE_DYN, -- 2.30.2