Commit 012ae244 authored by Anju T Sudhakar's avatar Anju T Sudhakar Committed by Michael Ellerman
Browse files

powerpc/perf: Trace imc PMU functions 



Add PMU functions to support trace-imc.

Signed-off-by: default avatarAnju T Sudhakar <anju@linux.vnet.ibm.com>
Reviewed-by: default avatarMadhavan Srinivasan <maddy@linux.vnet.ibm.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent 72c69dcd

arch/powerpc/perf/imc-pmu.c

+204 −1
Original line number Diff line number Diff line
@@ -53,7 +53,7 @@ static 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(event, "config:0-61");

PMU_FORMAT_ATTR(offset, "config:0-31");

PMU_FORMAT_ATTR(rvalue, "config:32");

PMU_FORMAT_ATTR(mode, "config:33-40");
@@ -70,6 +70,25 @@ static struct attribute_group imc_format_group = { 
	.attrs = imc_format_attrs,

};



/* Format attribute for imc trace-mode */

PMU_FORMAT_ATTR(cpmc_reserved, "config:0-19");

PMU_FORMAT_ATTR(cpmc_event, "config:20-27");

PMU_FORMAT_ATTR(cpmc_samplesel, "config:28-29");

PMU_FORMAT_ATTR(cpmc_load, "config:30-61");

static struct attribute *trace_imc_format_attrs[] = {

	&format_attr_event.attr,

	&format_attr_cpmc_reserved.attr,

	&format_attr_cpmc_event.attr,

	&format_attr_cpmc_samplesel.attr,

	&format_attr_cpmc_load.attr,

	NULL,

};



static struct attribute_group trace_imc_format_group = {

.name = "format",

.attrs = trace_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,
@@ -1113,6 +1132,182 @@ static int trace_imc_cpu_init(void) 
			  ppc_trace_imc_cpu_offline);

}



static u64 get_trace_imc_event_base_addr(void)

{

	return (u64)per_cpu(trace_imc_mem, smp_processor_id());

}



/*

 * Function to parse trace-imc data obtained

 * and to prepare the perf sample.

 */

static int trace_imc_prepare_sample(struct trace_imc_data *mem,

				    struct perf_sample_data *data,

				    u64 *prev_tb,

				    struct perf_event_header *header,

				    struct perf_event *event)

{

	/* Sanity checks for a valid record */

	if (be64_to_cpu(READ_ONCE(mem->tb1)) > *prev_tb)

		*prev_tb = be64_to_cpu(READ_ONCE(mem->tb1));

	else

		return -EINVAL;



	if ((be64_to_cpu(READ_ONCE(mem->tb1)) & IMC_TRACE_RECORD_TB1_MASK) !=

			 be64_to_cpu(READ_ONCE(mem->tb2)))

		return -EINVAL;



	/* Prepare perf sample */

	data->ip =  be64_to_cpu(READ_ONCE(mem->ip));

	data->period = event->hw.last_period;



	header->type = PERF_RECORD_SAMPLE;

	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;



	perf_event_header__init_id(header, data, event);



	return 0;

}



static void dump_trace_imc_data(struct perf_event *event)

{

	struct trace_imc_data *mem;

	int i, ret;

	u64 prev_tb = 0;



	mem = (struct trace_imc_data *)get_trace_imc_event_base_addr();

	for (i = 0; i < (trace_imc_mem_size / sizeof(struct trace_imc_data));

		i++, mem++) {

		struct perf_sample_data data;

		struct perf_event_header header;



		ret = trace_imc_prepare_sample(mem, &data, &prev_tb, &header, event);

		if (ret) /* Exit, if not a valid record */

			break;

		else {

			/* If this is a valid record, create the sample */

			struct perf_output_handle handle;



			if (perf_output_begin(&handle, event, header.size))

				return;



			perf_output_sample(&handle, &header, &data, event);

			perf_output_end(&handle);

		}

	}

}



static int trace_imc_event_add(struct perf_event *event, int flags)

{

	int core_id = smp_processor_id() / threads_per_core;

	struct imc_pmu_ref *ref = NULL;

	u64 local_mem, ldbar_value;



	/* Set trace-imc bit in ldbar and load ldbar with per-thread memory address */

	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];

	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;

	}

	mtspr(SPRN_LDBAR, ldbar_value);

	mutex_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);

			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);



	return 0;

}



static void trace_imc_event_read(struct perf_event *event)

{

	return;

}



static void trace_imc_event_stop(struct perf_event *event, int flags)

{

	u64 local_mem = get_trace_imc_event_base_addr();

	dump_trace_imc_data(event);

	memset((void *)local_mem, 0, sizeof(u64));

}



static void trace_imc_event_start(struct perf_event *event, int flags)

{

	return;

}



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 (!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;

	}

	mtspr(SPRN_LDBAR, 0);

	mutex_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);

			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);

	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))

		return -EACCES;



	/* Return if this is a couting event */

	if (event->attr.sample_period == 0)

		return -ENOENT;



	event->hw.idx = -1;

	target = event->hw.target;



	event->pmu->task_ctx_nr = perf_hw_context;

	return 0;

}



/* update_pmu_ops : Populate the appropriate operations for "pmu" */

static int update_pmu_ops(struct imc_pmu *pmu)

{
@@ -1143,6 +1338,14 @@ static int update_pmu_ops(struct imc_pmu *pmu) 
		pmu->pmu.cancel_txn = thread_imc_pmu_cancel_txn;

		pmu->pmu.commit_txn = thread_imc_pmu_commit_txn;

		break;

	case IMC_DOMAIN_TRACE:

		pmu->pmu.event_init = trace_imc_event_init;

		pmu->pmu.add = trace_imc_event_add;

		pmu->pmu.del = trace_imc_event_del;

		pmu->pmu.start = trace_imc_event_start;

		pmu->pmu.stop = trace_imc_event_stop;

		pmu->pmu.read = trace_imc_event_read;

		pmu->attr_groups[IMC_FORMAT_ATTR] = &trace_imc_format_group;

	default:

		break;

	}