diff options
Diffstat (limited to 'arch/powerpc/perf/imc-pmu.c')
| -rw-r--r-- | arch/powerpc/perf/imc-pmu.c | 1410 |
1 files changed, 1410 insertions, 0 deletions
diff --git a/arch/powerpc/perf/imc-pmu.c b/arch/powerpc/perf/imc-pmu.c new file mode 100644 index 000000000..555322677 --- /dev/null +++ b/arch/powerpc/perf/imc-pmu.c @@ -0,0 +1,1410 @@ +/* + * In-Memory Collection (IMC) Performance Monitor counter support. + * + * Copyright (C) 2017 Madhavan Srinivasan, IBM Corporation. + * (C) 2017 Anju T Sudhakar, IBM Corporation. + * (C) 2017 Hemant K Shaw, IBM Corporation. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or later version. + */ +#include <linux/perf_event.h> +#include <linux/slab.h> +#include <asm/opal.h> +#include <asm/imc-pmu.h> +#include <asm/cputhreads.h> +#include <asm/smp.h> +#include <linux/string.h> + +/* Nest IMC data structures and variables */ + +/* + * Used to avoid races in counting the nest-pmu units during hotplug + * register and unregister + */ +static DEFINE_MUTEX(nest_init_lock); +static DEFINE_PER_CPU(struct imc_pmu_ref *, local_nest_imc_refc); +static struct imc_pmu **per_nest_pmu_arr; +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; + +/* 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); +} + +PMU_FORMAT_ATTR(event, "config:0-40"); +PMU_FORMAT_ATTR(offset, "config:0-31"); +PMU_FORMAT_ATTR(rvalue, "config:32"); +PMU_FORMAT_ATTR(mode, "config:33-40"); +static struct attribute *imc_format_attrs[] = { + &format_attr_event.attr, + &format_attr_offset.attr, + &format_attr_rvalue.attr, + &format_attr_mode.attr, + NULL, +}; + +static struct attribute_group imc_format_group = { + .name = "format", + .attrs = imc_format_attrs, +}; + +/* Get the cpumask printed to a buffer "buf" */ +static ssize_t imc_pmu_cpumask_get_attr(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct pmu *pmu = dev_get_drvdata(dev); + struct imc_pmu *imc_pmu = container_of(pmu, struct imc_pmu, pmu); + cpumask_t *active_mask; + + 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; + } + + return cpumap_print_to_pagebuf(true, buf, active_mask); +} + +static DEVICE_ATTR(cpumask, S_IRUGO, imc_pmu_cpumask_get_attr, NULL); + +static struct attribute *imc_pmu_cpumask_attrs[] = { + &dev_attr_cpumask.attr, + NULL, +}; + +static struct attribute_group imc_pmu_cpumask_attr_group = { + .attrs = imc_pmu_cpumask_attrs, +}; + +/* device_str_attr_create : Populate event "name" and string "str" in attribute */ +static struct attribute *device_str_attr_create(const char *name, const char *str) +{ + struct perf_pmu_events_attr *attr; + + attr = kzalloc(sizeof(*attr), GFP_KERNEL); + if (!attr) + return NULL; + sysfs_attr_init(&attr->attr.attr); + + attr->event_str = str; + attr->attr.attr.name = name; + attr->attr.attr.mode = 0444; + attr->attr.show = perf_event_sysfs_show; + + return &attr->attr.attr; +} + +static int imc_parse_event(struct device_node *np, const char *scale, + const char *unit, const char *prefix, + u32 base, struct imc_events *event) +{ + const char *s; + u32 reg; + + if (of_property_read_u32(np, "reg", ®)) + goto error; + /* Add the base_reg value to the "reg" */ + event->value = base + reg; + + if (of_property_read_string(np, "event-name", &s)) + goto error; + + event->name = kasprintf(GFP_KERNEL, "%s%s", prefix, s); + if (!event->name) + goto error; + + if (of_property_read_string(np, "scale", &s)) + s = scale; + + if (s) { + event->scale = kstrdup(s, GFP_KERNEL); + if (!event->scale) + goto error; + } + + if (of_property_read_string(np, "unit", &s)) + s = unit; + + if (s) { + event->unit = kstrdup(s, GFP_KERNEL); + if (!event->unit) + goto error; + } + + return 0; +error: + kfree(event->unit); + kfree(event->scale); + kfree(event->name); + return -EINVAL; +} + +/* + * imc_free_events: Function to cleanup the events list, having + * "nr_entries". + */ +static void imc_free_events(struct imc_events *events, int nr_entries) +{ + int i; + + /* Nothing to clean, return */ + if (!events) + return; + for (i = 0; i < nr_entries; i++) { + kfree(events[i].unit); + kfree(events[i].scale); + kfree(events[i].name); + } + + kfree(events); +} + +/* + * update_events_in_group: Update the "events" information in an attr_group + * and assign the attr_group to the pmu "pmu". + */ +static int update_events_in_group(struct device_node *node, struct imc_pmu *pmu) +{ + struct attribute_group *attr_group; + struct attribute **attrs, *dev_str; + struct device_node *np, *pmu_events; + u32 handle, base_reg; + int i = 0, j = 0, ct, ret; + const char *prefix, *g_scale, *g_unit; + const char *ev_val_str, *ev_scale_str, *ev_unit_str; + + if (!of_property_read_u32(node, "events", &handle)) + pmu_events = of_find_node_by_phandle(handle); + else + return 0; + + /* Did not find any node with a given phandle */ + if (!pmu_events) + return 0; + + /* Get a count of number of child nodes */ + ct = of_get_child_count(pmu_events); + + /* Get the event prefix */ + if (of_property_read_string(node, "events-prefix", &prefix)) + return 0; + + /* Get a global unit and scale data if available */ + if (of_property_read_string(node, "scale", &g_scale)) + g_scale = NULL; + + if (of_property_read_string(node, "unit", &g_unit)) + g_unit = NULL; + + /* "reg" property gives out the base offset of the counters data */ + of_property_read_u32(node, "reg", &base_reg); + + /* Allocate memory for the events */ + pmu->events = kcalloc(ct, sizeof(struct imc_events), GFP_KERNEL); + if (!pmu->events) + return -ENOMEM; + + ct = 0; + /* Parse the events and update the struct */ + for_each_child_of_node(pmu_events, np) { + ret = imc_parse_event(np, g_scale, g_unit, prefix, base_reg, &pmu->events[ct]); + if (!ret) + ct++; + } + + /* Allocate memory for attribute group */ + attr_group = kzalloc(sizeof(*attr_group), GFP_KERNEL); + if (!attr_group) { + imc_free_events(pmu->events, ct); + return -ENOMEM; + } + + /* + * Allocate memory for attributes. + * Since we have count of events for this pmu, we also allocate + * memory for the scale and unit attribute for now. + * "ct" has the total event structs added from the events-parent node. + * So allocate three times the "ct" (this includes event, event_scale and + * event_unit). + */ + attrs = kcalloc(((ct * 3) + 1), sizeof(struct attribute *), GFP_KERNEL); + if (!attrs) { + kfree(attr_group); + imc_free_events(pmu->events, ct); + return -ENOMEM; + } + + attr_group->name = "events"; + attr_group->attrs = attrs; + do { + ev_val_str = kasprintf(GFP_KERNEL, "event=0x%x", pmu->events[i].value); + dev_str = device_str_attr_create(pmu->events[i].name, ev_val_str); + if (!dev_str) + continue; + + attrs[j++] = dev_str; + if (pmu->events[i].scale) { + ev_scale_str = kasprintf(GFP_KERNEL, "%s.scale", pmu->events[i].name); + dev_str = device_str_attr_create(ev_scale_str, pmu->events[i].scale); + if (!dev_str) + continue; + + attrs[j++] = dev_str; + } + + if (pmu->events[i].unit) { + ev_unit_str = kasprintf(GFP_KERNEL, "%s.unit", pmu->events[i].name); + dev_str = device_str_attr_create(ev_unit_str, pmu->events[i].unit); + if (!dev_str) + continue; + + attrs[j++] = dev_str; + } + } while (++i < ct); + + /* Save the event attribute */ + pmu->attr_groups[IMC_EVENT_ATTR] = attr_group; + + return 0; +} + +/* get_nest_pmu_ref: Return the imc_pmu_ref struct for the given node */ +static struct imc_pmu_ref *get_nest_pmu_ref(int cpu) +{ + return per_cpu(local_nest_imc_refc, cpu); +} + +static void nest_change_cpu_context(int old_cpu, int new_cpu) +{ + struct imc_pmu **pn = per_nest_pmu_arr; + + if (old_cpu < 0 || new_cpu < 0) + return; + + while (*pn) { + perf_pmu_migrate_context(&(*pn)->pmu, old_cpu, new_cpu); + pn++; + } +} + +static int ppc_nest_imc_cpu_offline(unsigned int cpu) +{ + int nid, target = -1; + const struct cpumask *l_cpumask; + struct imc_pmu_ref *ref; + + /* + * Check in the designated list for this cpu. Dont bother + * if not one of them. + */ + if (!cpumask_test_and_clear_cpu(cpu, &nest_imc_cpumask)) + return 0; + + /* + * Check whether nest_imc is registered. We could end up here if the + * cpuhotplug callback registration fails. i.e, callback invokes the + * offline path for all successfully registered nodes. At this stage, + * nest_imc pmu will not be registered and we should return here. + * + * We return with a zero since this is not an offline failure. And + * cpuhp_setup_state() returns the actual failure reason to the caller, + * which in turn will call the cleanup routine. + */ + if (!nest_pmus) + return 0; + + /* + * Now that this cpu is one of the designated, + * find a next cpu a) which is online and b) in same chip. + */ + nid = cpu_to_node(cpu); + l_cpumask = cpumask_of_node(nid); + target = cpumask_any_but(l_cpumask, cpu); + + /* + * Update the cpumask with the target cpu and + * migrate the context if needed + */ + if (target >= 0 && target < nr_cpu_ids) { + cpumask_set_cpu(target, &nest_imc_cpumask); + nest_change_cpu_context(cpu, target); + } else { + opal_imc_counters_stop(OPAL_IMC_COUNTERS_NEST, + get_hard_smp_processor_id(cpu)); + /* + * If this is the last cpu in this chip then, skip the reference + * count mutex lock and make the reference count on this chip zero. + */ + ref = get_nest_pmu_ref(cpu); + if (!ref) + return -EINVAL; + + ref->refc = 0; + } + return 0; +} + +static int ppc_nest_imc_cpu_online(unsigned int cpu) +{ + const struct cpumask *l_cpumask; + static struct cpumask tmp_mask; + int res; + + /* Get the cpumask of this node */ + l_cpumask = cpumask_of_node(cpu_to_node(cpu)); + + /* + * If this is not the first online CPU on this node, then + * just return. + */ + if (cpumask_and(&tmp_mask, l_cpumask, &nest_imc_cpumask)) + return 0; + + /* + * If this is the first online cpu on this node + * disable the nest counters by making an OPAL call. + */ + res = opal_imc_counters_stop(OPAL_IMC_COUNTERS_NEST, + get_hard_smp_processor_id(cpu)); + if (res) + return res; + + /* Make this CPU the designated target for counter collection */ + cpumask_set_cpu(cpu, &nest_imc_cpumask); + return 0; +} + +static int nest_pmu_cpumask_init(void) +{ + return cpuhp_setup_state(CPUHP_AP_PERF_POWERPC_NEST_IMC_ONLINE, + "perf/powerpc/imc:online", + ppc_nest_imc_cpu_online, + ppc_nest_imc_cpu_offline); +} + +static void nest_imc_counters_release(struct perf_event *event) +{ + int rc, node_id; + struct imc_pmu_ref *ref; + + if (event->cpu < 0) + return; + + node_id = cpu_to_node(event->cpu); + + /* + * See if we need to disable the nest 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 nest counters. + */ + ref = get_nest_pmu_ref(event->cpu); + if (!ref) + return; + + /* Take the mutex lock for this node and then decrement the reference count */ + mutex_lock(&ref->lock); + if (ref->refc == 0) { + /* + * The scenario where this is true is, when perf session is + * started, followed by offlining of all cpus in a given node. + * + * In the cpuhotplug offline path, ppc_nest_imc_cpu_offline() + * function set the ref->count to zero, if the cpu which is + * about to offline is the last cpu in a given node and make + * an OPAL call to disable the engine in that node. + * + */ + mutex_unlock(&ref->lock); + return; + } + ref->refc--; + if (ref->refc == 0) { + rc = opal_imc_counters_stop(OPAL_IMC_COUNTERS_NEST, + get_hard_smp_processor_id(event->cpu)); + if (rc) { + mutex_unlock(&ref->lock); + pr_err("nest-imc: Unable to stop the counters for core %d\n", node_id); + return; + } + } else if (ref->refc < 0) { + WARN(1, "nest-imc: Invalid event reference count\n"); + ref->refc = 0; + } + mutex_unlock(&ref->lock); +} + +static int nest_imc_event_init(struct perf_event *event) +{ + int chip_id, rc, node_id; + u32 l_config, config = event->attr.config; + struct imc_mem_info *pcni; + struct imc_pmu *pmu; + struct imc_pmu_ref *ref; + bool flag = false; + + 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; + + pmu = imc_event_to_pmu(event); + + /* Sanity check for config (event offset) */ + if ((config & IMC_EVENT_OFFSET_MASK) > pmu->counter_mem_size) + return -EINVAL; + + /* + * Nest HW counter memory resides in a per-chip reserve-memory (HOMER). + * Get the base memory addresss for this cpu. + */ + chip_id = cpu_to_chip_id(event->cpu); + + /* Return, if chip_id is not valid */ + if (chip_id < 0) + return -ENODEV; + + pcni = pmu->mem_info; + do { + if (pcni->id == chip_id) { + flag = true; + break; + } + pcni++; + } while (pcni->vbase != 0); + + if (!flag) + return -ENODEV; + + /* + * Add the event offset to the base address. + */ + l_config = config & IMC_EVENT_OFFSET_MASK; + event->hw.event_base = (u64)pcni->vbase + l_config; + node_id = cpu_to_node(event->cpu); + + /* + * Get the imc_pmu_ref struct for this node. + * Take the mutex lock and then increment the count of nest pmu events + * inited. + */ + ref = get_nest_pmu_ref(event->cpu); + if (!ref) + return -EINVAL; + + mutex_lock(&ref->lock); + if (ref->refc == 0) { + rc = opal_imc_counters_start(OPAL_IMC_COUNTERS_NEST, + get_hard_smp_processor_id(event->cpu)); + if (rc) { + mutex_unlock(&ref->lock); + pr_err("nest-imc: Unable to start the counters for node %d\n", + node_id); + return rc; + } + } + ++ref->refc; + mutex_unlock(&ref->lock); + + event->destroy = nest_imc_counters_release; + 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 nid, 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. + */ + nid = cpu_to_node(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(nid, + GFP_KERNEL | __GFP_ZERO | __GFP_THISNODE | + __GFP_NOWARN, 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 core_id; + int ncpu; + 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; + + /* + * Check whether core_imc is registered. We could end up here + * if the cpuhotplug callback registration fails. i.e, callback + * invokes the offline path for all sucessfully registered cpus. + * At this stage, core_imc pmu will not be registered and we + * should return here. + * + * We return with a zero since this is not an offline failure. + * And cpuhp_setup_state() returns the actual failure reason + * to the caller, which inturn will call the cleanup routine. + */ + if (!core_imc_pmu->pmu.event_init) + 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); + if (ref->refc == 0) { + /* + * The scenario where this is true is, when perf session is + * started, followed by offlining of all cpus in a given core. + * + * In the cpuhotplug offline path, ppc_core_imc_cpu_offline() + * function set the ref->count to zero, if the cpu which is + * about to offline is the last cpu in a given core and make + * an OPAL call to disable the engine in that core. + * + */ + mutex_unlock(&ref->lock); + return; + } + 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; +} + +/* + * 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 nid = cpu_to_node(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(nid, + GFP_KERNEL | __GFP_ZERO | __GFP_THISNODE | + __GFP_NOWARN, 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); +} + +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; + + /* + * In-Memory Collection (IMC) counters are free flowing counters. + * So we take a snapshot of the counter value on enable and save it + * to calculate the delta at later stage to present the event counter + * value. + */ + addr = get_event_base_addr(event); + data = be64_to_cpu(READ_ONCE(*addr)); + local64_set(&event->hw.prev_count, data); + + return data; +} + +static void imc_event_update(struct perf_event *event) +{ + u64 counter_prev, counter_new, final_count; + + counter_prev = local64_read(&event->hw.prev_count); + counter_new = imc_read_counter(event); + final_count = counter_new - counter_prev; + + /* Update the delta to the event count */ + local64_add(final_count, &event->count); +} + +static void imc_event_start(struct perf_event *event, int flags) +{ + /* + * In Memory Counters are free flowing counters. HW or the microcode + * keeps adding to the counter offset in memory. To get event + * counter value, we snapshot the value here and we calculate + * delta at later point. + */ + imc_read_counter(event); +} + +static void imc_event_stop(struct perf_event *event, int flags) +{ + /* + * Take a snapshot and calculate the delta and update + * the event counter values. + */ + imc_event_update(event); +} + +static int imc_event_add(struct perf_event *event, int flags) +{ + if (flags & PERF_EF_START) + imc_event_start(event, flags); + + return 0; +} + +static int thread_imc_event_add(struct perf_event *event, int flags) +{ + int core_id; + struct imc_pmu_ref *ref; + + if (flags & PERF_EF_START) + imc_event_start(event, flags); + + if (!is_core_imc_mem_inited(smp_processor_id())) + return -EINVAL; + + core_id = smp_processor_id() / threads_per_core; + /* + * 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 -EINVAL; + + 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 -EINVAL; + } + } + ++ref->refc; + mutex_unlock(&ref->lock); + return 0; +} + +static void thread_imc_event_del(struct perf_event *event, int flags) +{ + + int core_id; + struct imc_pmu_ref *ref; + + /* + * Take a snapshot and calculate the delta and update + * the event counter values. + */ + imc_event_update(event); + + core_id = smp_processor_id() / threads_per_core; + ref = &core_imc_refc[core_id]; + + 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); +} + +/* update_pmu_ops : Populate the appropriate operations for "pmu" */ +static int update_pmu_ops(struct imc_pmu *pmu) +{ + pmu->pmu.task_ctx_nr = perf_invalid_context; + pmu->pmu.add = imc_event_add; + pmu->pmu.del = imc_event_stop; + pmu->pmu.start = imc_event_start; + pmu->pmu.stop = imc_event_stop; + pmu->pmu.read = imc_event_update; + pmu->pmu.attr_groups = pmu->attr_groups; + pmu->attr_groups[IMC_FORMAT_ATTR] = &imc_format_group; + + 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; + case IMC_DOMAIN_THREAD: + pmu->pmu.event_init = thread_imc_event_init; + 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; + } + + return 0; +} + +/* init_nest_pmu_ref: Initialize the imc_pmu_ref struct for all the nodes */ +static int init_nest_pmu_ref(void) +{ + int nid, i, cpu; + + nest_imc_refc = kcalloc(num_possible_nodes(), sizeof(*nest_imc_refc), + GFP_KERNEL); + + if (!nest_imc_refc) + return -ENOMEM; + + i = 0; + for_each_node(nid) { + /* + * Mutex lock to avoid races while tracking the number of + * sessions using the chip's nest pmu units. + */ + mutex_init(&nest_imc_refc[i].lock); + + /* + * Loop to init the "id" with the node_id. Variable "i" initialized to + * 0 and will be used as index to the array. "i" will not go off the + * end of the array since the "for_each_node" loops for "N_POSSIBLE" + * nodes only. + */ + nest_imc_refc[i++].id = nid; + } + + /* + * Loop to init the per_cpu "local_nest_imc_refc" with the proper + * "nest_imc_refc" index. This makes get_nest_pmu_ref() alot simple. + */ + for_each_possible_cpu(cpu) { + nid = cpu_to_node(cpu); + for (i = 0; i < num_possible_nodes(); i++) { + if (nest_imc_refc[i].id == nid) { + per_cpu(local_nest_imc_refc, cpu) = &nest_imc_refc[i]; + break; + } + } + } + return 0; +} + +static void cleanup_all_core_imc_memory(void) +{ + int i, nr_cores = DIV_ROUND_UP(num_possible_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[i].vbase, get_order(size)); + } + + kfree(ptr); + 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); + + } +} + +/* Function to free the attr_groups which are dynamically allocated */ +static void imc_common_mem_free(struct imc_pmu *pmu_ptr) +{ + if (pmu_ptr->attr_groups[IMC_EVENT_ATTR]) + kfree(pmu_ptr->attr_groups[IMC_EVENT_ATTR]->attrs); + kfree(pmu_ptr->attr_groups[IMC_EVENT_ATTR]); +} + +/* + * Common function to unregister cpu hotplug callback and + * free the memory. + * TODO: Need to handle pmu unregistering, which will be + * done in followup series. + */ +static void imc_common_cpuhp_mem_free(struct imc_pmu *pmu_ptr) +{ + if (pmu_ptr->domain == IMC_DOMAIN_NEST) { + mutex_lock(&nest_init_lock); + if (nest_pmus == 1) { + cpuhp_remove_state(CPUHP_AP_PERF_POWERPC_NEST_IMC_ONLINE); + kfree(nest_imc_refc); + kfree(per_nest_pmu_arr); + per_nest_pmu_arr = NULL; + } + + if (nest_pmus > 0) + nest_pmus--; + 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(); + } + + /* 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(); + } +} + +/* + * Function to unregister thread-imc if core-imc + * is not registered. + */ +void unregister_thread_imc(void) +{ + imc_common_cpuhp_mem_free(thread_imc_pmu); + imc_common_mem_free(thread_imc_pmu); + perf_pmu_unregister(&thread_imc_pmu->pmu); +} + +/* + * imc_mem_init : Function to support memory allocation for core imc. + */ +static int imc_mem_init(struct imc_pmu *pmu_ptr, struct device_node *parent, + int pmu_index) +{ + const char *s; + int nr_cores, cpu, res = -ENOMEM; + + if (of_property_read_string(parent, "name", &s)) + return -ENODEV; + + switch (pmu_ptr->domain) { + case IMC_DOMAIN_NEST: + /* Update the pmu name */ + pmu_ptr->pmu.name = kasprintf(GFP_KERNEL, "%s%s_imc", "nest_", s); + if (!pmu_ptr->pmu.name) + goto err; + + /* Needed for hotplug/migration */ + if (!per_nest_pmu_arr) { + per_nest_pmu_arr = kcalloc(get_max_nest_dev() + 1, + sizeof(struct imc_pmu *), + GFP_KERNEL); + if (!per_nest_pmu_arr) + goto err; + } + 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) + goto err; + + nr_cores = DIV_ROUND_UP(num_possible_cpus(), threads_per_core); + pmu_ptr->mem_info = kcalloc(nr_cores, sizeof(struct imc_mem_info), + GFP_KERNEL); + + if (!pmu_ptr->mem_info) + goto err; + + core_imc_refc = kcalloc(nr_cores, sizeof(struct imc_pmu_ref), + GFP_KERNEL); + + if (!core_imc_refc) { + kfree(pmu_ptr->mem_info); + goto err; + } + + 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) + goto err; + + 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) { + cleanup_all_thread_imc_memory(); + goto err; + } + } + + thread_imc_pmu = pmu_ptr; + break; + default: + return -EINVAL; + } + + return 0; +err: + return res; +} + +/* + * init_imc_pmu : Setup and register the IMC pmu device. + * + * @parent: Device tree unit node + * @pmu_ptr: memory allocated for this pmu + * @pmu_idx: Count of nest pmc registered + * + * init_imc_pmu() setup pmu cpumask and registers for a cpu hotplug callback. + * Handles failure cases and accordingly frees memory. + */ +int init_imc_pmu(struct device_node *parent, struct imc_pmu *pmu_ptr, int pmu_idx) +{ + int ret; + + ret = imc_mem_init(pmu_ptr, parent, pmu_idx); + if (ret) + goto err_free_mem; + + switch (pmu_ptr->domain) { + case IMC_DOMAIN_NEST: + /* + * Nest imc pmu need only one cpu per chip, we initialize the + * cpumask for the first nest imc pmu and use the same for the + * rest. To handle the cpuhotplug callback unregister, we track + * the number of nest pmus in "nest_pmus". + */ + mutex_lock(&nest_init_lock); + if (nest_pmus == 0) { + ret = init_nest_pmu_ref(); + if (ret) { + mutex_unlock(&nest_init_lock); + kfree(per_nest_pmu_arr); + per_nest_pmu_arr = NULL; + goto err_free_mem; + } + /* Register for cpu hotplug notification. */ + ret = nest_pmu_cpumask_init(); + if (ret) { + mutex_unlock(&nest_init_lock); + kfree(nest_imc_refc); + kfree(per_nest_pmu_arr); + per_nest_pmu_arr = NULL; + goto err_free_mem; + } + } + 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(); + goto err_free_mem; + } + + break; + case IMC_DOMAIN_THREAD: + ret = thread_imc_cpu_init(); + if (ret) { + cleanup_all_thread_imc_memory(); + goto err_free_mem; + } + + break; + default: + return -EINVAL; /* Unknown domain */ + } + + ret = update_events_in_group(parent, pmu_ptr); + if (ret) + goto err_free_cpuhp_mem; + + ret = update_pmu_ops(pmu_ptr); + if (ret) + goto err_free_cpuhp_mem; + + ret = perf_pmu_register(&pmu_ptr->pmu, pmu_ptr->pmu.name, -1); + if (ret) + goto err_free_cpuhp_mem; + + pr_info("%s performance monitor hardware support registered\n", + pmu_ptr->pmu.name); + + return 0; + +err_free_cpuhp_mem: + imc_common_cpuhp_mem_free(pmu_ptr); +err_free_mem: + imc_common_mem_free(pmu_ptr); + return ret; +} |