Re: [PATCH v13 4/5] powerpc/perf: Add core imc pmu support
From: Madhavan Srinivasan
Date: Sat Jul 22 2017 - 03:13:00 EST
my bad, missed to change the authership of this patch.
From: Anju T Sudhakar <anju@xxxxxxxxxxxxxxxxxx>
On Wednesday 19 July 2017 03:06 AM, Madhavan Srinivasan wrote:
Add support to register Core In-Memory Collection pmu counters.
Patch adds core imc specific data structures, along with memory
init functions and cpuhotplug support.
Signed-off-by: Anju T Sudhakar <anju@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Hemant Kumar <hemant@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Madhavan Srinivasan <maddy@xxxxxxxxxxxxxxxxxx>
---
arch/powerpc/perf/imc-pmu.c | 303 +++++++++++++++++++++++++++++++++++++++++++-
include/linux/cpuhotplug.h | 1 +
2 files changed, 299 insertions(+), 5 deletions(-)
diff --git a/arch/powerpc/perf/imc-pmu.c b/arch/powerpc/perf/imc-pmu.c
index 6e00ea7358a2..cd8ba3b98d29 100644
--- a/arch/powerpc/perf/imc-pmu.c
+++ b/arch/powerpc/perf/imc-pmu.c
@@ -18,7 +18,6 @@
#include <asm/smp.h>
#include <linux/string.h>
-//Nest imc data structures and variable
/*
* Used to avoid races in counting the nest-pmu units during hotplug
* register and unregister
@@ -30,6 +29,11 @@ static cpumask_t nest_imc_cpumask;
struct imc_pmu_ref *nest_imc_refc;
static int nest_pmus;
+//Core imc data structs 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);
@@ -61,11 +65,13 @@ 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;
}
@@ -485,6 +491,240 @@ 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)
{
/*
@@ -563,12 +803,15 @@ 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;
}
@@ -620,6 +863,22 @@ 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.
@@ -640,6 +899,12 @@ 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]);
@@ -655,11 +920,11 @@ 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 */
@@ -670,6 +935,27 @@ 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;
}
@@ -695,7 +981,6 @@ 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 +1006,14 @@ 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,