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Diffstat (limited to 'arch/powerpc/perf/imc-pmu.c')
-rw-r--r--arch/powerpc/perf/imc-pmu.c342
1 files changed, 249 insertions, 93 deletions
diff --git a/arch/powerpc/perf/imc-pmu.c b/arch/powerpc/perf/imc-pmu.c
index cb50a9e1fd2d..8664a7d297ad 100644
--- a/arch/powerpc/perf/imc-pmu.c
+++ b/arch/powerpc/perf/imc-pmu.c
@@ -6,6 +6,7 @@
* (C) 2017 Anju T Sudhakar, IBM Corporation.
* (C) 2017 Hemant K Shaw, IBM Corporation.
*/
+#include <linux/of.h>
#include <linux/perf_event.h>
#include <linux/slab.h>
#include <asm/opal.h>
@@ -13,6 +14,7 @@
#include <asm/cputhreads.h>
#include <asm/smp.h>
#include <linux/string.h>
+#include <linux/spinlock.h>
/* Nest IMC data structures and variables */
@@ -44,6 +46,16 @@ static DEFINE_PER_CPU(u64 *, trace_imc_mem);
static struct imc_pmu_ref *trace_imc_refc;
static int trace_imc_mem_size;
+/*
+ * Global data structure used to avoid races between thread,
+ * core and trace-imc
+ */
+static struct imc_pmu_ref imc_global_refc = {
+ .lock = __SPIN_LOCK_UNLOCKED(imc_global_refc.lock),
+ .id = 0,
+ .refc = 0,
+};
+
static struct imc_pmu *imc_event_to_pmu(struct perf_event *event)
{
return container_of(event->pmu, struct imc_pmu, pmu);
@@ -61,7 +73,7 @@ static struct attribute *imc_format_attrs[] = {
NULL,
};
-static struct attribute_group imc_format_group = {
+static const struct attribute_group imc_format_group = {
.name = "format",
.attrs = imc_format_attrs,
};
@@ -80,7 +92,7 @@ static struct attribute *trace_imc_format_attrs[] = {
NULL,
};
-static struct attribute_group trace_imc_format_group = {
+static const struct attribute_group trace_imc_format_group = {
.name = "format",
.attrs = trace_imc_format_attrs,
};
@@ -115,7 +127,7 @@ static struct attribute *imc_pmu_cpumask_attrs[] = {
NULL,
};
-static struct attribute_group imc_pmu_cpumask_attr_group = {
+static const struct attribute_group imc_pmu_cpumask_attr_group = {
.attrs = imc_pmu_cpumask_attrs,
};
@@ -229,8 +241,10 @@ static int update_events_in_group(struct device_node *node, struct imc_pmu *pmu)
ct = of_get_child_count(pmu_events);
/* Get the event prefix */
- if (of_property_read_string(node, "events-prefix", &prefix))
+ if (of_property_read_string(node, "events-prefix", &prefix)) {
+ of_node_put(pmu_events);
return 0;
+ }
/* Get a global unit and scale data if available */
if (of_property_read_string(node, "scale", &g_scale))
@@ -244,8 +258,10 @@ static int update_events_in_group(struct device_node *node, struct imc_pmu *pmu)
/* Allocate memory for the events */
pmu->events = kcalloc(ct, sizeof(struct imc_events), GFP_KERNEL);
- if (!pmu->events)
+ if (!pmu->events) {
+ of_node_put(pmu_events);
return -ENOMEM;
+ }
ct = 0;
/* Parse the events and update the struct */
@@ -255,6 +271,8 @@ static int update_events_in_group(struct device_node *node, struct imc_pmu *pmu)
ct++;
}
+ of_node_put(pmu_events);
+
/* Allocate memory for attribute group */
attr_group = kzalloc(sizeof(*attr_group), GFP_KERNEL);
if (!attr_group) {
@@ -281,6 +299,8 @@ static int update_events_in_group(struct device_node *node, struct imc_pmu *pmu)
attr_group->attrs = attrs;
do {
ev_val_str = kasprintf(GFP_KERNEL, "event=0x%x", pmu->events[i].value);
+ if (!ev_val_str)
+ continue;
dev_str = device_str_attr_create(pmu->events[i].name, ev_val_str);
if (!dev_str)
continue;
@@ -288,6 +308,8 @@ static int update_events_in_group(struct device_node *node, struct imc_pmu *pmu)
attrs[j++] = dev_str;
if (pmu->events[i].scale) {
ev_scale_str = kasprintf(GFP_KERNEL, "%s.scale", pmu->events[i].name);
+ if (!ev_scale_str)
+ continue;
dev_str = device_str_attr_create(ev_scale_str, pmu->events[i].scale);
if (!dev_str)
continue;
@@ -297,6 +319,8 @@ static int update_events_in_group(struct device_node *node, struct imc_pmu *pmu)
if (pmu->events[i].unit) {
ev_unit_str = kasprintf(GFP_KERNEL, "%s.unit", pmu->events[i].name);
+ if (!ev_unit_str)
+ continue;
dev_str = device_str_attr_create(ev_unit_str, pmu->events[i].unit);
if (!dev_str)
continue;
@@ -383,7 +407,7 @@ static int ppc_nest_imc_cpu_offline(unsigned int cpu)
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.
+ * count lock and make the reference count on this chip zero.
*/
ref = get_nest_pmu_ref(cpu);
if (!ref)
@@ -445,15 +469,15 @@ static void nest_imc_counters_release(struct perf_event *event)
/*
* 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
+ * lock 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);
+ /* Take the lock for this node and then decrement the reference count */
+ spin_lock(&ref->lock);
if (ref->refc == 0) {
/*
* The scenario where this is true is, when perf session is
@@ -465,7 +489,7 @@ static void nest_imc_counters_release(struct perf_event *event)
* an OPAL call to disable the engine in that node.
*
*/
- mutex_unlock(&ref->lock);
+ spin_unlock(&ref->lock);
return;
}
ref->refc--;
@@ -473,7 +497,7 @@ static void nest_imc_counters_release(struct perf_event *event)
rc = opal_imc_counters_stop(OPAL_IMC_COUNTERS_NEST,
get_hard_smp_processor_id(event->cpu));
if (rc) {
- mutex_unlock(&ref->lock);
+ spin_unlock(&ref->lock);
pr_err("nest-imc: Unable to stop the counters for core %d\n", node_id);
return;
}
@@ -481,7 +505,7 @@ static void nest_imc_counters_release(struct perf_event *event)
WARN(1, "nest-imc: Invalid event reference count\n");
ref->refc = 0;
}
- mutex_unlock(&ref->lock);
+ spin_unlock(&ref->lock);
}
static int nest_imc_event_init(struct perf_event *event)
@@ -511,7 +535,7 @@ static int nest_imc_event_init(struct perf_event *event)
/*
* Nest HW counter memory resides in a per-chip reserve-memory (HOMER).
- * Get the base memory addresss for this cpu.
+ * Get the base memory address for this cpu.
*/
chip_id = cpu_to_chip_id(event->cpu);
@@ -526,7 +550,7 @@ static int nest_imc_event_init(struct perf_event *event)
break;
}
pcni++;
- } while (pcni->vbase != 0);
+ } while (pcni->vbase);
if (!flag)
return -ENODEV;
@@ -540,26 +564,25 @@ static int nest_imc_event_init(struct perf_event *event)
/*
* Get the imc_pmu_ref struct for this node.
- * Take the mutex lock and then increment the count of nest pmu events
- * inited.
+ * Take the 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);
+ spin_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);
+ spin_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);
+ spin_unlock(&ref->lock);
event->destroy = nest_imc_counters_release;
return 0;
@@ -595,9 +618,8 @@ static int core_imc_mem_init(int cpu, int size)
return -ENOMEM;
mem_info->vbase = page_address(page);
- /* Init the mutex */
core_imc_refc[core_id].id = core_id;
- mutex_init(&core_imc_refc[core_id].lock);
+ spin_lock_init(&core_imc_refc[core_id].lock);
rc = opal_imc_counters_init(OPAL_IMC_COUNTERS_CORE,
__pa((void *)mem_info->vbase),
@@ -664,7 +686,7 @@ static int ppc_core_imc_cpu_offline(unsigned int cpu)
/*
* 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.
+ * invokes the offline path for all successfully registered cpus.
* At this stage, core_imc pmu will not be registered and we
* should return here.
*
@@ -686,9 +708,8 @@ static int ppc_core_imc_cpu_offline(unsigned int cpu)
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.
+ * If this is the last cpu in this core then skip taking reference
+ * count 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));
@@ -698,6 +719,16 @@ static int ppc_core_imc_cpu_offline(unsigned int cpu)
return -EINVAL;
ref->refc = 0;
+ /*
+ * Reduce the global reference count, if this is the
+ * last cpu in this core and core-imc event running
+ * in this cpu.
+ */
+ spin_lock(&imc_global_refc.lock);
+ if (imc_global_refc.id == IMC_DOMAIN_CORE)
+ imc_global_refc.refc--;
+
+ spin_unlock(&imc_global_refc.lock);
}
return 0;
}
@@ -710,6 +741,23 @@ static int core_imc_pmu_cpumask_init(void)
ppc_core_imc_cpu_offline);
}
+static void reset_global_refc(struct perf_event *event)
+{
+ spin_lock(&imc_global_refc.lock);
+ imc_global_refc.refc--;
+
+ /*
+ * If no other thread is running any
+ * event for this domain(thread/core/trace),
+ * set the global id to zero.
+ */
+ if (imc_global_refc.refc <= 0) {
+ imc_global_refc.refc = 0;
+ imc_global_refc.id = 0;
+ }
+ spin_unlock(&imc_global_refc.lock);
+}
+
static void core_imc_counters_release(struct perf_event *event)
{
int rc, core_id;
@@ -720,17 +768,17 @@ static void core_imc_counters_release(struct perf_event *event)
/*
* 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
+ * lock 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 */
+ /* Take the lock and decrement the refernce count for this core */
ref = &core_imc_refc[core_id];
if (!ref)
return;
- mutex_lock(&ref->lock);
+ spin_lock(&ref->lock);
if (ref->refc == 0) {
/*
* The scenario where this is true is, when perf session is
@@ -742,7 +790,7 @@ static void core_imc_counters_release(struct perf_event *event)
* an OPAL call to disable the engine in that core.
*
*/
- mutex_unlock(&ref->lock);
+ spin_unlock(&ref->lock);
return;
}
ref->refc--;
@@ -750,7 +798,7 @@ static void core_imc_counters_release(struct perf_event *event)
rc = opal_imc_counters_stop(OPAL_IMC_COUNTERS_CORE,
get_hard_smp_processor_id(event->cpu));
if (rc) {
- mutex_unlock(&ref->lock);
+ spin_unlock(&ref->lock);
pr_err("IMC: Unable to stop the counters for core %d\n", core_id);
return;
}
@@ -758,7 +806,9 @@ static void core_imc_counters_release(struct perf_event *event)
WARN(1, "core-imc: Invalid event reference count\n");
ref->refc = 0;
}
- mutex_unlock(&ref->lock);
+ spin_unlock(&ref->lock);
+
+ reset_global_refc(event);
}
static int core_imc_event_init(struct perf_event *event)
@@ -794,7 +844,6 @@ static int core_imc_event_init(struct perf_event *event)
if ((!pcmi->vbase))
return -ENODEV;
- /* Get the core_imc mutex for this core */
ref = &core_imc_refc[core_id];
if (!ref)
return -EINVAL;
@@ -802,22 +851,45 @@ static int core_imc_event_init(struct perf_event *event)
/*
* 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 yes, take the lock and enable the core counters.
* If not, just increment the count in core_imc_refc struct.
*/
- mutex_lock(&ref->lock);
+ spin_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);
+ spin_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);
+ spin_unlock(&ref->lock);
+
+ /*
+ * Since the system can run either in accumulation or trace-mode
+ * of IMC at a time, core-imc events are allowed only if no other
+ * trace/thread imc events are enabled/monitored.
+ *
+ * Take the global lock, and check the refc.id
+ * to know whether any other trace/thread imc
+ * events are running.
+ */
+ spin_lock(&imc_global_refc.lock);
+ if (imc_global_refc.id == 0 || imc_global_refc.id == IMC_DOMAIN_CORE) {
+ /*
+ * No other trace/thread imc events are running in
+ * the system, so set the refc.id to core-imc.
+ */
+ imc_global_refc.id = IMC_DOMAIN_CORE;
+ imc_global_refc.refc++;
+ } else {
+ spin_unlock(&imc_global_refc.lock);
+ return -EBUSY;
+ }
+ spin_unlock(&imc_global_refc.lock);
event->hw.event_base = (u64)pcmi->vbase + (config & IMC_EVENT_OFFSET_MASK);
event->destroy = core_imc_counters_release;
@@ -877,7 +949,23 @@ static int ppc_thread_imc_cpu_online(unsigned int cpu)
static int ppc_thread_imc_cpu_offline(unsigned int cpu)
{
- mtspr(SPRN_LDBAR, 0);
+ /*
+ * Set the bit 0 of LDBAR to zero.
+ *
+ * If bit 0 of LDBAR is unset, it will stop posting
+ * the counter data to memory.
+ * For thread-imc, bit 0 of LDBAR will be set to 1 in the
+ * event_add function. So reset this bit here, to stop the updates
+ * to memory in the cpu_offline path.
+ */
+ mtspr(SPRN_LDBAR, (mfspr(SPRN_LDBAR) & (~(1UL << 63))));
+
+ /* Reduce the refc if thread-imc event running on this cpu */
+ spin_lock(&imc_global_refc.lock);
+ if (imc_global_refc.id == IMC_DOMAIN_THREAD)
+ imc_global_refc.refc--;
+ spin_unlock(&imc_global_refc.lock);
+
return 0;
}
@@ -898,7 +986,7 @@ static int thread_imc_event_init(struct perf_event *event)
if (event->attr.type != event->pmu->type)
return -ENOENT;
- if (!capable(CAP_SYS_ADMIN))
+ if (!perfmon_capable())
return -EACCES;
/* Sampling not supported */
@@ -916,7 +1004,22 @@ static int thread_imc_event_init(struct perf_event *event)
if (!target)
return -EINVAL;
+ spin_lock(&imc_global_refc.lock);
+ /*
+ * Check if any other trace/core imc events are running in the
+ * system, if not set the global id to thread-imc.
+ */
+ if (imc_global_refc.id == 0 || imc_global_refc.id == IMC_DOMAIN_THREAD) {
+ imc_global_refc.id = IMC_DOMAIN_THREAD;
+ imc_global_refc.refc++;
+ } else {
+ spin_unlock(&imc_global_refc.lock);
+ return -EBUSY;
+ }
+ spin_unlock(&imc_global_refc.lock);
+
event->pmu->task_ctx_nr = perf_sw_context;
+ event->destroy = reset_global_refc;
return 0;
}
@@ -928,16 +1031,16 @@ static bool is_thread_imc_pmu(struct perf_event *event)
return false;
}
-static u64 * get_event_base_addr(struct perf_event *event)
+static __be64 *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 (__be64 *)(addr + (event->attr.config & IMC_EVENT_OFFSET_MASK));
}
- return (u64 *)event->hw.event_base;
+ return (__be64 *)event->hw.event_base;
}
static void thread_imc_pmu_start_txn(struct pmu *pmu,
@@ -961,7 +1064,8 @@ static int thread_imc_pmu_commit_txn(struct pmu *pmu)
static u64 imc_read_counter(struct perf_event *event)
{
- u64 *addr, data;
+ __be64 *addr;
+ u64 data;
/*
* In-Memory Collection (IMC) counters are free flowing counters.
@@ -1035,25 +1139,25 @@ static int thread_imc_event_add(struct perf_event *event, int flags)
/*
* 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 yes, take the 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);
+ spin_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);
+ spin_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);
+ spin_unlock(&ref->lock);
return 0;
}
@@ -1063,17 +1167,19 @@ static void thread_imc_event_del(struct perf_event *event, int flags)
int core_id;
struct imc_pmu_ref *ref;
- mtspr(SPRN_LDBAR, 0);
-
core_id = smp_processor_id() / threads_per_core;
ref = &core_imc_refc[core_id];
+ if (!ref) {
+ pr_debug("imc: Failed to get event reference count\n");
+ return;
+ }
- mutex_lock(&ref->lock);
+ spin_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);
+ spin_unlock(&ref->lock);
pr_err("thread-imc: Unable to stop the counters\
for core %d\n", core_id);
return;
@@ -1081,7 +1187,11 @@ static void thread_imc_event_del(struct perf_event *event, int flags)
} else if (ref->refc < 0) {
ref->refc = 0;
}
- mutex_unlock(&ref->lock);
+ spin_unlock(&ref->lock);
+
+ /* Set bit 0 of LDBAR to zero, to stop posting updates to memory */
+ mtspr(SPRN_LDBAR, (mfspr(SPRN_LDBAR) & (~(1UL << 63))));
+
/*
* Take a snapshot and calculate the delta and update
* the event counter values.
@@ -1118,9 +1228,8 @@ static int trace_imc_mem_alloc(int cpu_id, int size)
}
}
- /* Init the mutex, if not already */
trace_imc_refc[core_id].id = core_id;
- mutex_init(&trace_imc_refc[core_id].lock);
+ spin_lock_init(&trace_imc_refc[core_id].lock);
mtspr(SPRN_LDBAR, 0);
return 0;
@@ -1133,7 +1242,18 @@ static int ppc_trace_imc_cpu_online(unsigned int cpu)
static int ppc_trace_imc_cpu_offline(unsigned int cpu)
{
- mtspr(SPRN_LDBAR, 0);
+ /*
+ * No need to set bit 0 of LDBAR to zero, as
+ * it is set to zero for imc trace-mode
+ *
+ * Reduce the refc if any trace-imc event running
+ * on this cpu.
+ */
+ spin_lock(&imc_global_refc.lock);
+ if (imc_global_refc.id == IMC_DOMAIN_TRACE)
+ imc_global_refc.refc--;
+ spin_unlock(&imc_global_refc.lock);
+
return 0;
}
@@ -1178,11 +1298,30 @@ static int trace_imc_prepare_sample(struct trace_imc_data *mem,
header->size = sizeof(*header) + event->header_size;
header->misc = 0;
- if (is_kernel_addr(data->ip))
- header->misc |= PERF_RECORD_MISC_KERNEL;
- else
- header->misc |= PERF_RECORD_MISC_USER;
-
+ if (cpu_has_feature(CPU_FTR_ARCH_31)) {
+ switch (IMC_TRACE_RECORD_VAL_HVPR(be64_to_cpu(READ_ONCE(mem->val)))) {
+ case 0:/* when MSR HV and PR not set in the trace-record */
+ header->misc |= PERF_RECORD_MISC_GUEST_KERNEL;
+ break;
+ case 1: /* MSR HV is 0 and PR is 1 */
+ header->misc |= PERF_RECORD_MISC_GUEST_USER;
+ break;
+ case 2: /* MSR HV is 1 and PR is 0 */
+ header->misc |= PERF_RECORD_MISC_KERNEL;
+ break;
+ case 3: /* MSR HV is 1 and PR is 1 */
+ header->misc |= PERF_RECORD_MISC_USER;
+ break;
+ default:
+ pr_info("IMC: Unable to set the flag based on MSR bits\n");
+ break;
+ }
+ } else {
+ if (is_kernel_addr(data->ip))
+ header->misc |= PERF_RECORD_MISC_KERNEL;
+ else
+ header->misc |= PERF_RECORD_MISC_USER;
+ }
perf_event_header__init_id(header, data, event);
return 0;
@@ -1207,7 +1346,7 @@ static void dump_trace_imc_data(struct perf_event *event)
/* If this is a valid record, create the sample */
struct perf_output_handle handle;
- if (perf_output_begin(&handle, event, header.size))
+ if (perf_output_begin(&handle, &data, event, header.size))
return;
perf_output_sample(&handle, &header, &data, event);
@@ -1226,29 +1365,26 @@ static int trace_imc_event_add(struct perf_event *event, int flags)
local_mem = get_trace_imc_event_base_addr();
ldbar_value = ((u64)local_mem & THREAD_IMC_LDBAR_MASK) | TRACE_IMC_ENABLE;
- if (core_imc_refc)
- ref = &core_imc_refc[core_id];
+ /* trace-imc reference count */
+ if (trace_imc_refc)
+ ref = &trace_imc_refc[core_id];
if (!ref) {
- /* If core-imc is not enabled, use trace-imc reference count */
- if (trace_imc_refc)
- ref = &trace_imc_refc[core_id];
- if (!ref)
- return -EINVAL;
+ pr_debug("imc: Failed to get the event reference count\n");
+ return -EINVAL;
}
+
mtspr(SPRN_LDBAR, ldbar_value);
- mutex_lock(&ref->lock);
+ spin_lock(&ref->lock);
if (ref->refc == 0) {
if (opal_imc_counters_start(OPAL_IMC_COUNTERS_TRACE,
get_hard_smp_processor_id(smp_processor_id()))) {
- mutex_unlock(&ref->lock);
+ spin_unlock(&ref->lock);
pr_err("trace-imc: Unable to start the counters for core %d\n", core_id);
- mtspr(SPRN_LDBAR, 0);
return -EINVAL;
}
}
++ref->refc;
- mutex_unlock(&ref->lock);
-
+ spin_unlock(&ref->lock);
return 0;
}
@@ -1274,50 +1410,69 @@ static void trace_imc_event_del(struct perf_event *event, int flags)
int core_id = smp_processor_id() / threads_per_core;
struct imc_pmu_ref *ref = NULL;
- if (core_imc_refc)
- ref = &core_imc_refc[core_id];
+ if (trace_imc_refc)
+ ref = &trace_imc_refc[core_id];
if (!ref) {
- /* If core-imc is not enabled, use trace-imc reference count */
- if (trace_imc_refc)
- ref = &trace_imc_refc[core_id];
- if (!ref)
- return;
+ pr_debug("imc: Failed to get event reference count\n");
+ return;
}
- mtspr(SPRN_LDBAR, 0);
- mutex_lock(&ref->lock);
+
+ spin_lock(&ref->lock);
ref->refc--;
if (ref->refc == 0) {
if (opal_imc_counters_stop(OPAL_IMC_COUNTERS_TRACE,
get_hard_smp_processor_id(smp_processor_id()))) {
- mutex_unlock(&ref->lock);
+ spin_unlock(&ref->lock);
pr_err("trace-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);
+ spin_unlock(&ref->lock);
+
trace_imc_event_stop(event, flags);
}
static int trace_imc_event_init(struct perf_event *event)
{
- struct task_struct *target;
-
if (event->attr.type != event->pmu->type)
return -ENOENT;
- if (!capable(CAP_SYS_ADMIN))
+ if (!perfmon_capable())
return -EACCES;
/* Return if this is a couting event */
if (event->attr.sample_period == 0)
return -ENOENT;
+ /*
+ * Take the global lock, and make sure
+ * no other thread is running any core/thread imc
+ * events
+ */
+ spin_lock(&imc_global_refc.lock);
+ if (imc_global_refc.id == 0 || imc_global_refc.id == IMC_DOMAIN_TRACE) {
+ /*
+ * No core/thread imc events are running in the
+ * system, so set the refc.id to trace-imc.
+ */
+ imc_global_refc.id = IMC_DOMAIN_TRACE;
+ imc_global_refc.refc++;
+ } else {
+ spin_unlock(&imc_global_refc.lock);
+ return -EBUSY;
+ }
+ spin_unlock(&imc_global_refc.lock);
+
event->hw.idx = -1;
- target = event->hw.target;
- event->pmu->task_ctx_nr = perf_hw_context;
+ /*
+ * There can only be a single PMU for perf_hw_context events which is assigned to
+ * core PMU. Hence use "perf_sw_context" for trace_imc.
+ */
+ event->pmu->task_ctx_nr = perf_sw_context;
+ event->destroy = reset_global_refc;
return 0;
}
@@ -1359,6 +1514,7 @@ static int update_pmu_ops(struct imc_pmu *pmu)
pmu->pmu.stop = trace_imc_event_stop;
pmu->pmu.read = trace_imc_event_read;
pmu->attr_groups[IMC_FORMAT_ATTR] = &trace_imc_format_group;
+ break;
default:
break;
}
@@ -1380,10 +1536,10 @@ static int init_nest_pmu_ref(void)
i = 0;
for_each_node(nid) {
/*
- * Mutex lock to avoid races while tracking the number of
+ * Take the lock to avoid races while tracking the number of
* sessions using the chip's nest pmu units.
*/
- mutex_init(&nest_imc_refc[i].lock);
+ spin_lock_init(&nest_imc_refc[i].lock);
/*
* Loop to init the "id" with the node_id. Variable "i" initialized to
@@ -1429,10 +1585,10 @@ static void cleanup_all_core_imc_memory(void)
static void thread_imc_ldbar_disable(void *dummy)
{
/*
- * By Zeroing LDBAR, we disable thread-imc
- * updates.
+ * By setting 0th bit of LDBAR to zero, we disable thread-imc
+ * updates to memory.
*/
- mtspr(SPRN_LDBAR, 0);
+ mtspr(SPRN_LDBAR, (mfspr(SPRN_LDBAR) & (~(1UL << 63))));
}
void thread_imc_disable(void)
generated by cgit (git 2.34.1) at 2024-05-09 14:51:14 +0000