From f74c89bd80fb3f1328fdf4a44eeba793cdce4222 Mon Sep 17 00:00:00 2001 From: Anju T Sudhakar Date: Wed, 19 Jul 2017 03:06:36 +0530 Subject: [PATCH] powerpc/perf: Add thread IMC PMU support Add support to register Thread In-Memory Collection PMU counters. Patch adds thread 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 | 270 +++++++++++++++++++++++++++++++++++- include/linux/cpuhotplug.h | 1 + 2 files changed, 267 insertions(+), 4 deletions(-) diff --git a/arch/powerpc/perf/imc-pmu.c b/arch/powerpc/perf/imc-pmu.c index 482f8d6d5e65..46cd912af060 100644 --- a/arch/powerpc/perf/imc-pmu.c +++ b/arch/powerpc/perf/imc-pmu.c @@ -37,6 +37,12 @@ static cpumask_t core_imc_cpumask; struct imc_pmu_ref *core_imc_refc; static struct imc_pmu *core_imc_pmu; +/* Thread IMC data structures and variables */ + +static DEFINE_PER_CPU(u64 *, thread_imc_mem); +static struct imc_pmu *thread_imc_pmu; +static int thread_imc_mem_size; + struct imc_pmu *imc_event_to_pmu(struct perf_event *event) { return container_of(event->pmu, struct imc_pmu, pmu); @@ -728,15 +734,188 @@ static int core_imc_event_init(struct perf_event *event) return 0; } -static u64 * get_event_base_addr(struct perf_event *event) +/* + * Allocates a page of memory for each of the online cpus, and write the + * physical base address of that page to the LDBAR for that cpu. + * + * LDBAR Register Layout: + * + * 0 4 8 12 16 20 24 28 + * | - - - - | - - - - | - - - - | - - - - | - - - - | - - - - | - - - - | - - - - | + * | | [ ] [ Counter Address [8:50] + * | * Mode | + * | * PB Scope + * * Enable/Disable + * + * 32 36 40 44 48 52 56 60 + * | - - - - | - - - - | - - - - | - - - - | - - - - | - - - - | - - - - | - - - - | + * Counter Address [8:50] ] + * + */ +static int thread_imc_mem_alloc(int cpu_id, int size) +{ + u64 ldbar_value, *local_mem = per_cpu(thread_imc_mem, cpu_id); + int phys_id = topology_physical_package_id(cpu_id); + + if (!local_mem) { + /* + * This case could happen only once at start, since we dont + * free the memory in cpu offline path. + */ + local_mem = page_address(alloc_pages_node(phys_id, + GFP_KERNEL | __GFP_ZERO | __GFP_THISNODE, + get_order(size))); + if (!local_mem) + return -ENOMEM; + + per_cpu(thread_imc_mem, cpu_id) = local_mem; + } + + ldbar_value = ((u64)local_mem & THREAD_IMC_LDBAR_MASK) | THREAD_IMC_ENABLE; + + mtspr(SPRN_LDBAR, ldbar_value); + return 0; +} + +static int ppc_thread_imc_cpu_online(unsigned int cpu) { + return thread_imc_mem_alloc(cpu, thread_imc_mem_size); +} + +static int ppc_thread_imc_cpu_offline(unsigned int cpu) +{ + mtspr(SPRN_LDBAR, 0); + return 0; +} + +static int thread_imc_cpu_init(void) +{ + return cpuhp_setup_state(CPUHP_AP_PERF_POWERPC_THREAD_IMC_ONLINE, + "perf/powerpc/imc_thread:online", + ppc_thread_imc_cpu_online, + ppc_thread_imc_cpu_offline); +} + +void thread_imc_pmu_sched_task(struct perf_event_context *ctx, + bool sched_in) +{ + int core_id; + struct imc_pmu_ref *ref; + + if (!is_core_imc_mem_inited(smp_processor_id())) + return; + + core_id = smp_processor_id() / threads_per_core; /* - * Subsequent patch will add code to detect caller imc pmu - * and return accordingly. + * imc pmus 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 counters. + * If not, just increment the count in ref count struct. */ + ref = &core_imc_refc[core_id]; + if (!ref) + return; + + if (sched_in) { + mutex_lock(&ref->lock); + if (ref->refc == 0) { + if (opal_imc_counters_start(OPAL_IMC_COUNTERS_CORE, + get_hard_smp_processor_id(smp_processor_id()))) { + mutex_unlock(&ref->lock); + pr_err("thread-imc: Unable to start the counter\ + for core %d\n", core_id); + return; + } + } + ++ref->refc; + mutex_unlock(&ref->lock); + } else { + mutex_lock(&ref->lock); + ref->refc--; + if (ref->refc == 0) { + if (opal_imc_counters_stop(OPAL_IMC_COUNTERS_CORE, + get_hard_smp_processor_id(smp_processor_id()))) { + mutex_unlock(&ref->lock); + pr_err("thread-imc: Unable to stop the counters\ + for core %d\n", core_id); + return; + } + } else if (ref->refc < 0) { + ref->refc = 0; + } + mutex_unlock(&ref->lock); + } + + return; +} + +static int thread_imc_event_init(struct perf_event *event) +{ + u32 config = event->attr.config; + struct task_struct *target; + struct imc_pmu *pmu; + + if (event->attr.type != event->pmu->type) + return -ENOENT; + + /* Sampling not supported */ + if (event->hw.sample_period) + return -EINVAL; + + event->hw.idx = -1; + pmu = imc_event_to_pmu(event); + + /* Sanity check for config offset */ + if (((config & IMC_EVENT_OFFSET_MASK) > pmu->counter_mem_size)) + return -EINVAL; + + target = event->hw.target; + if (!target) + return -EINVAL; + + event->pmu->task_ctx_nr = perf_sw_context; + return 0; +} + +static bool is_thread_imc_pmu(struct perf_event *event) +{ + if (!strncmp(event->pmu->name, "thread_imc", strlen("thread_imc"))) + return true; + + return false; +} + +static u64 * get_event_base_addr(struct perf_event *event) +{ + u64 addr; + + if (is_thread_imc_pmu(event)) { + addr = (u64)per_cpu(thread_imc_mem, smp_processor_id()); + return (u64 *)(addr + (event->attr.config & IMC_EVENT_OFFSET_MASK)); + } + return (u64 *)event->hw.event_base; } +static void thread_imc_pmu_start_txn(struct pmu *pmu, + unsigned int txn_flags) +{ + if (txn_flags & ~PERF_PMU_TXN_ADD) + return; + perf_pmu_disable(pmu); +} + +static void thread_imc_pmu_cancel_txn(struct pmu *pmu) +{ + perf_pmu_enable(pmu); +} + +static int thread_imc_pmu_commit_txn(struct pmu *pmu) +{ + perf_pmu_enable(pmu); + return 0; +} + static u64 imc_read_counter(struct perf_event *event) { u64 *addr, data; @@ -794,6 +973,26 @@ static int imc_event_add(struct perf_event *event, int flags) return 0; } +static int thread_imc_event_add(struct perf_event *event, int flags) +{ + if (flags & PERF_EF_START) + imc_event_start(event, flags); + + /* Enable the sched_task to start the engine */ + perf_sched_cb_inc(event->ctx->pmu); + return 0; +} + +static void thread_imc_event_del(struct perf_event *event, int flags) +{ + /* + * Take a snapshot and calculate the delta and update + * the event counter values. + */ + imc_event_update(event); + perf_sched_cb_dec(event->ctx->pmu); +} + /* update_pmu_ops : Populate the appropriate operations for "pmu" */ static int update_pmu_ops(struct imc_pmu *pmu) { @@ -815,6 +1014,15 @@ static int update_pmu_ops(struct imc_pmu *pmu) pmu->pmu.event_init = core_imc_event_init; pmu->attr_groups[IMC_CPUMASK_ATTR] = &imc_pmu_cpumask_attr_group; break; + case IMC_DOMAIN_THREAD: + pmu->pmu.event_init = thread_imc_event_init; + pmu->pmu.sched_task = thread_imc_pmu_sched_task; + pmu->pmu.add = thread_imc_event_add; + pmu->pmu.del = thread_imc_event_del; + pmu->pmu.start_txn = thread_imc_pmu_start_txn; + pmu->pmu.cancel_txn = thread_imc_pmu_cancel_txn; + pmu->pmu.commit_txn = thread_imc_pmu_commit_txn; + break; default: break; } @@ -882,6 +1090,31 @@ static void cleanup_all_core_imc_memory(void) kfree(core_imc_refc); } +static void thread_imc_ldbar_disable(void *dummy) +{ + /* + * By Zeroing LDBAR, we disable thread-imc + * updates. + */ + mtspr(SPRN_LDBAR, 0); +} + +void thread_imc_disable(void) +{ + on_each_cpu(thread_imc_ldbar_disable, NULL, 1); +} + +static void cleanup_all_thread_imc_memory(void) +{ + int i, order = get_order(thread_imc_mem_size); + + for_each_online_cpu(i) { + if (per_cpu(thread_imc_mem, i)) + free_pages((u64)per_cpu(thread_imc_mem, i), order); + + } +} + /* * Common function to unregister cpu hotplug callback and * free the memory. @@ -908,6 +1141,12 @@ static void imc_common_cpuhp_mem_free(struct imc_pmu *pmu_ptr) cleanup_all_core_imc_memory(); } + /* Free thread_imc memory */ + if (pmu_ptr->domain == IMC_DOMAIN_THREAD) { + cpuhp_remove_state(CPUHP_AP_PERF_POWERPC_THREAD_IMC_ONLINE); + cleanup_all_thread_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]); @@ -923,7 +1162,7 @@ static int imc_mem_init(struct imc_pmu *pmu_ptr, struct device_node *parent, int pmu_index) { const char *s; - int nr_cores; + int nr_cores, cpu, res; if (of_property_read_string(parent, "name", &s)) return -ENODEV; @@ -959,6 +1198,21 @@ static int imc_mem_init(struct imc_pmu *pmu_ptr, struct device_node *parent, core_imc_pmu = pmu_ptr; break; + case IMC_DOMAIN_THREAD: + /* Update the pmu name */ + pmu_ptr->pmu.name = kasprintf(GFP_KERNEL, "%s%s", s, "_imc"); + if (!pmu_ptr->pmu.name) + return -ENOMEM; + + thread_imc_mem_size = pmu_ptr->counter_mem_size; + for_each_online_cpu(cpu) { + res = thread_imc_mem_alloc(cpu, pmu_ptr->counter_mem_size); + if (res) + return res; + } + + thread_imc_pmu = pmu_ptr; + break; default: return -EINVAL; } @@ -1016,6 +1270,14 @@ int init_imc_pmu(struct device_node *parent, struct imc_pmu *pmu_ptr, int pmu_id return ret; } + break; + case IMC_DOMAIN_THREAD: + ret = thread_imc_cpu_init(); + if (ret) { + cleanup_all_thread_imc_memory(); + return ret; + } + break; default: return -1; /* Unknown domain */ diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h index 1be505db0090..1bc7dcfbf7b3 100644 --- a/include/linux/cpuhotplug.h +++ b/include/linux/cpuhotplug.h @@ -141,6 +141,7 @@ enum cpuhp_state { CPUHP_AP_PERF_ARM_QCOM_L3_ONLINE, CPUHP_AP_PERF_POWERPC_NEST_IMC_ONLINE, CPUHP_AP_PERF_POWERPC_CORE_IMC_ONLINE, + CPUHP_AP_PERF_POWERPC_THREAD_IMC_ONLINE, CPUHP_AP_WORKQUEUE_ONLINE, CPUHP_AP_RCUTREE_ONLINE, CPUHP_AP_ONLINE_DYN, -- 2.30.2