arch/powerpc/perf/hv-gpci.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * Hypervisor supplied "gpci" ("get performance counter info") performance
  * counter support
  *
  * Author: Cody P Schafer <cody@linux.vnet.ibm.com>
  * Copyright 2014 IBM Corporation.
  */

 #define pr_fmt(fmt) "hv-gpci: " fmt

 #include <linux/init.h>
 #include <linux/perf_event.h>
 #include <asm/firmware.h>
 #include <asm/hvcall.h>
 #include <asm/io.h>

 #include "hv-gpci.h"
 #include "hv-common.h"

 /*
  * Example usage:
  *  perf stat -e 'hv_gpci/counter_info_version=3,offset=0,length=8,
  *		  secondary_index=0,starting_index=0xffffffff,request=0x10/' ...
  */

 /* u32 */
 EVENT_DEFINE_RANGE_FORMAT(request, config, 0, 31);
 /* u32 */
 /*
  * Note that starting_index, phys_processor_idx, sibling_part_id,
  * hw_chip_id, partition_id all refer to the same bit range. They
  * are basically aliases for the starting_index. The specific alias
  * used depends on the event. See REQUEST_IDX_KIND in hv-gpci-requests.h
  */
 EVENT_DEFINE_RANGE_FORMAT(starting_index, config, 32, 63);
 EVENT_DEFINE_RANGE_FORMAT_LITE(phys_processor_idx, config, 32, 63);
 EVENT_DEFINE_RANGE_FORMAT_LITE(sibling_part_id, config, 32, 63);
 EVENT_DEFINE_RANGE_FORMAT_LITE(hw_chip_id, config, 32, 63);
 EVENT_DEFINE_RANGE_FORMAT_LITE(partition_id, config, 32, 63);

 /* u16 */
 EVENT_DEFINE_RANGE_FORMAT(secondary_index, config1, 0, 15);
 /* u8 */
 EVENT_DEFINE_RANGE_FORMAT(counter_info_version, config1, 16, 23);
 /* u8, bytes of data (1-8) */
 EVENT_DEFINE_RANGE_FORMAT(length, config1, 24, 31);
 /* u32, byte offset */
 EVENT_DEFINE_RANGE_FORMAT(offset, config1, 32, 63);

 static cpumask_t hv_gpci_cpumask;

 static struct attribute *format_attrs[] = {
 	&format_attr_request.attr,
 	&format_attr_starting_index.attr,
 	&format_attr_phys_processor_idx.attr,
 	&format_attr_sibling_part_id.attr,
 	&format_attr_hw_chip_id.attr,
 	&format_attr_partition_id.attr,
 	&format_attr_secondary_index.attr,
 	&format_attr_counter_info_version.attr,

 	&format_attr_offset.attr,
 	&format_attr_length.attr,
 	NULL,
 };

 static struct attribute_group format_group = {
 	.name = "format",
 	.attrs = format_attrs,
 };

 static struct attribute_group event_group = {
 	.name  = "events",
 	.attrs = hv_gpci_event_attrs,
 };

 #define HV_CAPS_ATTR(_name, _format)				\
 static ssize_t _name##_show(struct device *dev,			\
 			    struct device_attribute *attr,	\
 			    char *page)				\
 {								\
 	struct hv_perf_caps caps;				\
 	unsigned long hret = hv_perf_caps_get(&caps);		\
 	if (hret)						\
 		return -EIO;					\
 								\
 	return sprintf(page, _format, caps._name);		\
 }								\
 static struct device_attribute hv_caps_attr_##_name = __ATTR_RO(_name)

 static ssize_t kernel_version_show(struct device *dev,
 				   struct device_attribute *attr,
 				   char *page)
 {
 	return sprintf(page, "0x%x\n", COUNTER_INFO_VERSION_CURRENT);
 }

 static ssize_t cpumask_show(struct device *dev,
 			    struct device_attribute *attr, char *buf)
 {
 	return cpumap_print_to_pagebuf(true, buf, &hv_gpci_cpumask);
 }

 static DEVICE_ATTR_RO(kernel_version);
 static DEVICE_ATTR_RO(cpumask);

 HV_CAPS_ATTR(version, "0x%x\n");
 HV_CAPS_ATTR(ga, "%d\n");
 HV_CAPS_ATTR(expanded, "%d\n");
 HV_CAPS_ATTR(lab, "%d\n");
 HV_CAPS_ATTR(collect_privileged, "%d\n");

 static struct attribute *interface_attrs[] = {
 	&dev_attr_kernel_version.attr,
 	&hv_caps_attr_version.attr,
 	&hv_caps_attr_ga.attr,
 	&hv_caps_attr_expanded.attr,
 	&hv_caps_attr_lab.attr,
 	&hv_caps_attr_collect_privileged.attr,
 	NULL,
 };

 static struct attribute *cpumask_attrs[] = {
 	&dev_attr_cpumask.attr,
 	NULL,
 };

 static struct attribute_group cpumask_attr_group = {
 	.attrs = cpumask_attrs,
 };

 static struct attribute_group interface_group = {
 	.name = "interface",
 	.attrs = interface_attrs,
 };

 static const struct attribute_group *attr_groups[] = {
 	&format_group,
 	&event_group,
 	&interface_group,
 	&cpumask_attr_group,
 	NULL,
 };

 static DEFINE_PER_CPU(char, hv_gpci_reqb[HGPCI_REQ_BUFFER_SIZE]) __aligned(sizeof(uint64_t));

 static unsigned long single_gpci_request(u32 req, u32 starting_index,
 		u16 secondary_index, u8 version_in, u32 offset, u8 length,
 		u64 *value)
 {
 	unsigned long ret;
 	size_t i;
 	u64 count;
 	struct hv_gpci_request_buffer *arg;

 	arg = (void *)get_cpu_var(hv_gpci_reqb);
 	memset(arg, 0, HGPCI_REQ_BUFFER_SIZE);

 	arg->params.counter_request = cpu_to_be32(req);
 	arg->params.starting_index = cpu_to_be32(starting_index);
 	arg->params.secondary_index = cpu_to_be16(secondary_index);
 	arg->params.counter_info_version_in = version_in;

 	ret = plpar_hcall_norets(H_GET_PERF_COUNTER_INFO,
 			virt_to_phys(arg), HGPCI_REQ_BUFFER_SIZE);
 	if (ret) {
 		pr_devel("hcall failed: 0x%lx\n", ret);
 		goto out;
 	}

 	/*
 	 * we verify offset and length are within the zeroed buffer at event
 	 * init.
 	 */
 	count = 0;
 	for (i = offset; i < offset + length; i++)
 		count |= arg->bytes[i] << (i - offset);

 	*value = count;
 out:
 	put_cpu_var(hv_gpci_reqb);
 	return ret;
 }

 static u64 h_gpci_get_value(struct perf_event *event)
 {
 	u64 count;
 	unsigned long ret = single_gpci_request(event_get_request(event),
 					event_get_starting_index(event),
 					event_get_secondary_index(event),
 					event_get_counter_info_version(event),
 					event_get_offset(event),
 					event_get_length(event),
 					&count);
 	if (ret)
 		return 0;
 	return count;
 }

 static void h_gpci_event_update(struct perf_event *event)
 {
 	s64 prev;
 	u64 now = h_gpci_get_value(event);
 	prev = local64_xchg(&event->hw.prev_count, now);
 	local64_add(now - prev, &event->count);
 }

 static void h_gpci_event_start(struct perf_event *event, int flags)
 {
 	local64_set(&event->hw.prev_count, h_gpci_get_value(event));
 }

 static void h_gpci_event_stop(struct perf_event *event, int flags)
 {
 	h_gpci_event_update(event);
 }

 static int h_gpci_event_add(struct perf_event *event, int flags)
 {
 	if (flags & PERF_EF_START)
 		h_gpci_event_start(event, flags);

 	return 0;
 }

 static int h_gpci_event_init(struct perf_event *event)
 {
 	u64 count;
 	u8 length;

 	/* Not our event */
 	if (event->attr.type != event->pmu->type)
 		return -ENOENT;

 	/* config2 is unused */
 	if (event->attr.config2) {
 		pr_devel("config2 set when reserved\n");
 		return -EINVAL;
 	}

 	/* no branch sampling */
 	if (has_branch_stack(event))
 		return -EOPNOTSUPP;

 	length = event_get_length(event);
 	if (length < 1 || length > 8) {
 		pr_devel("length invalid\n");
 		return -EINVAL;
 	}

 	/* last byte within the buffer? */
 	if ((event_get_offset(event) + length) > HGPCI_MAX_DATA_BYTES) {
 		pr_devel("request outside of buffer: %zu > %zu\n",
 				(size_t)event_get_offset(event) + length,
 				HGPCI_MAX_DATA_BYTES);
 		return -EINVAL;
 	}

 	/* check if the request works... */
 	if (single_gpci_request(event_get_request(event),
 				event_get_starting_index(event),
 				event_get_secondary_index(event),
 				event_get_counter_info_version(event),
 				event_get_offset(event),
 				length,
 				&count)) {
 		pr_devel("gpci hcall failed\n");
 		return -EINVAL;
 	}

 	return 0;
 }

 static struct pmu h_gpci_pmu = {
 	.task_ctx_nr = perf_invalid_context,

 	.name = "hv_gpci",
 	.attr_groups = attr_groups,
 	.event_init  = h_gpci_event_init,
 	.add         = h_gpci_event_add,
 	.del         = h_gpci_event_stop,
 	.start       = h_gpci_event_start,
 	.stop        = h_gpci_event_stop,
 	.read        = h_gpci_event_update,
 	.capabilities = PERF_PMU_CAP_NO_EXCLUDE,
 };

 static int ppc_hv_gpci_cpu_online(unsigned int cpu)
 {
 	if (cpumask_empty(&hv_gpci_cpumask))
 		cpumask_set_cpu(cpu, &hv_gpci_cpumask);

 	return 0;
 }

 static int ppc_hv_gpci_cpu_offline(unsigned int cpu)
 {
 	int target;

 	/* Check if exiting cpu is used for collecting gpci events */
 	if (!cpumask_test_and_clear_cpu(cpu, &hv_gpci_cpumask))
 		return 0;

 	/* Find a new cpu to collect gpci events */
 	target = cpumask_last(cpu_active_mask);

 	if (target < 0 || target >= nr_cpu_ids) {
 		pr_err("hv_gpci: CPU hotplug init failed\n");
 		return -1;
 	}

 	/* Migrate gpci events to the new target */
 	cpumask_set_cpu(target, &hv_gpci_cpumask);
 	perf_pmu_migrate_context(&h_gpci_pmu, cpu, target);

 	return 0;
 }

 static int hv_gpci_cpu_hotplug_init(void)
 {
 	return cpuhp_setup_state(CPUHP_AP_PERF_POWERPC_HV_GPCI_ONLINE,
 			  "perf/powerpc/hv_gcpi:online",
 			  ppc_hv_gpci_cpu_online,
 			  ppc_hv_gpci_cpu_offline);
 }

 static int hv_gpci_init(void)
 {
 	int r;
 	unsigned long hret;
 	struct hv_perf_caps caps;

 	hv_gpci_assert_offsets_correct();

 	if (!firmware_has_feature(FW_FEATURE_LPAR)) {
 		pr_debug("not a virtualized system, not enabling\n");
 		return -ENODEV;
 	}

 	hret = hv_perf_caps_get(&caps);
 	if (hret) {
 		pr_debug("could not obtain capabilities, not enabling, rc=%ld\n",
 				hret);
 		return -ENODEV;
 	}

 	/* init cpuhotplug */
 	r = hv_gpci_cpu_hotplug_init();
 	if (r)
 		return r;

 	/* sampling not supported */
 	h_gpci_pmu.capabilities |= PERF_PMU_CAP_NO_INTERRUPT;

 	r = perf_pmu_register(&h_gpci_pmu, h_gpci_pmu.name, -1);
 	if (r)
 		return r;

 	return 0;
 }

 device_initcall(hv_gpci_init);
	// SPDX-License-Identifier: GPL-2.0-or-later
	/*
	* Hypervisor supplied "gpci" ("get performance counter info") performance
	* counter support
	*
	* Author: Cody P Schafer <cody@linux.vnet.ibm.com>
	* Copyright 2014 IBM Corporation.
	*/

	#define pr_fmt(fmt) "hv-gpci: " fmt

	#include <linux/init.h>
	#include <linux/perf_event.h>
	#include <asm/firmware.h>
	#include <asm/hvcall.h>
	#include <asm/io.h>

	#include "hv-gpci.h"
	#include "hv-common.h"

	/*
	* Example usage:
	* perf stat -e 'hv_gpci/counter_info_version=3,offset=0,length=8,
	* secondary_index=0,starting_index=0xffffffff,request=0x10/' ...
	*/

	/* u32 */
	EVENT_DEFINE_RANGE_FORMAT(request, config, 0, 31);
	/* u32 */
	/*
	* Note that starting_index, phys_processor_idx, sibling_part_id,
	* hw_chip_id, partition_id all refer to the same bit range. They
	* are basically aliases for the starting_index. The specific alias
	* used depends on the event. See REQUEST_IDX_KIND in hv-gpci-requests.h
	*/
	EVENT_DEFINE_RANGE_FORMAT(starting_index, config, 32, 63);
	EVENT_DEFINE_RANGE_FORMAT_LITE(phys_processor_idx, config, 32, 63);
	EVENT_DEFINE_RANGE_FORMAT_LITE(sibling_part_id, config, 32, 63);
	EVENT_DEFINE_RANGE_FORMAT_LITE(hw_chip_id, config, 32, 63);
	EVENT_DEFINE_RANGE_FORMAT_LITE(partition_id, config, 32, 63);

	/* u16 */
	EVENT_DEFINE_RANGE_FORMAT(secondary_index, config1, 0, 15);
	/* u8 */
	EVENT_DEFINE_RANGE_FORMAT(counter_info_version, config1, 16, 23);
	/* u8, bytes of data (1-8) */
	EVENT_DEFINE_RANGE_FORMAT(length, config1, 24, 31);
	/* u32, byte offset */
	EVENT_DEFINE_RANGE_FORMAT(offset, config1, 32, 63);

	static cpumask_t hv_gpci_cpumask;

	static struct attribute *format_attrs[] = {
	&format_attr_request.attr,
	&format_attr_starting_index.attr,
	&format_attr_phys_processor_idx.attr,
	&format_attr_sibling_part_id.attr,
	&format_attr_hw_chip_id.attr,
	&format_attr_partition_id.attr,
	&format_attr_secondary_index.attr,
	&format_attr_counter_info_version.attr,

	&format_attr_offset.attr,
	&format_attr_length.attr,
	NULL,
	};

	static struct attribute_group format_group = {
	.name = "format",
	.attrs = format_attrs,
	};

	static struct attribute_group event_group = {
	.name = "events",
	.attrs = hv_gpci_event_attrs,
	};

	#define HV_CAPS_ATTR(_name, _format) \
	static ssize_t _name##_show(struct device *dev, \
	struct device_attribute *attr, \
	char *page) \
	{ \
	struct hv_perf_caps caps; \
	unsigned long hret = hv_perf_caps_get(&caps); \
	if (hret) \
	return -EIO; \
	\
	return sprintf(page, _format, caps._name); \
	} \
	static struct device_attribute hv_caps_attr_##_name = __ATTR_RO(_name)

	static ssize_t kernel_version_show(struct device *dev,
	struct device_attribute *attr,
	char *page)
	{
	return sprintf(page, "0x%x\n", COUNTER_INFO_VERSION_CURRENT);
	}

	static ssize_t cpumask_show(struct device *dev,
	struct device_attribute attr, char buf)
	{
	return cpumap_print_to_pagebuf(true, buf, &hv_gpci_cpumask);
	}

	static DEVICE_ATTR_RO(kernel_version);
	static DEVICE_ATTR_RO(cpumask);

	HV_CAPS_ATTR(version, "0x%x\n");
	HV_CAPS_ATTR(ga, "%d\n");
	HV_CAPS_ATTR(expanded, "%d\n");
	HV_CAPS_ATTR(lab, "%d\n");
	HV_CAPS_ATTR(collect_privileged, "%d\n");

	static struct attribute *interface_attrs[] = {
	&dev_attr_kernel_version.attr,
	&hv_caps_attr_version.attr,
	&hv_caps_attr_ga.attr,
	&hv_caps_attr_expanded.attr,
	&hv_caps_attr_lab.attr,
	&hv_caps_attr_collect_privileged.attr,
	NULL,
	};

	static struct attribute *cpumask_attrs[] = {
	&dev_attr_cpumask.attr,
	NULL,
	};

	static struct attribute_group cpumask_attr_group = {
	.attrs = cpumask_attrs,
	};

	static struct attribute_group interface_group = {
	.name = "interface",
	.attrs = interface_attrs,
	};

	static const struct attribute_group *attr_groups[] = {
	&format_group,
	&event_group,
	&interface_group,
	&cpumask_attr_group,
	NULL,
	};

	static DEFINE_PER_CPU(char, hv_gpci_reqb[HGPCI_REQ_BUFFER_SIZE]) __aligned(sizeof(uint64_t));

	static unsigned long single_gpci_request(u32 req, u32 starting_index,
	u16 secondary_index, u8 version_in, u32 offset, u8 length,
	u64 *value)
	{
	unsigned long ret;
	size_t i;
	u64 count;
	struct hv_gpci_request_buffer *arg;

	arg = (void *)get_cpu_var(hv_gpci_reqb);
	memset(arg, 0, HGPCI_REQ_BUFFER_SIZE);

	arg->params.counter_request = cpu_to_be32(req);
	arg->params.starting_index = cpu_to_be32(starting_index);
	arg->params.secondary_index = cpu_to_be16(secondary_index);
	arg->params.counter_info_version_in = version_in;

	ret = plpar_hcall_norets(H_GET_PERF_COUNTER_INFO,
	virt_to_phys(arg), HGPCI_REQ_BUFFER_SIZE);
	if (ret) {
	pr_devel("hcall failed: 0x%lx\n", ret);
	goto out;
	}

	/*
	* we verify offset and length are within the zeroed buffer at event
	* init.
	*/
	count = 0;
	for (i = offset; i < offset + length; i++)
	count \|= arg->bytes[i] << (i - offset);

	*value = count;
	out:
	put_cpu_var(hv_gpci_reqb);
	return ret;
	}

	static u64 h_gpci_get_value(struct perf_event *event)
	{
	u64 count;
	unsigned long ret = single_gpci_request(event_get_request(event),
	event_get_starting_index(event),
	event_get_secondary_index(event),
	event_get_counter_info_version(event),
	event_get_offset(event),
	event_get_length(event),
	&count);
	if (ret)
	return 0;
	return count;
	}

	static void h_gpci_event_update(struct perf_event *event)
	{
	s64 prev;
	u64 now = h_gpci_get_value(event);
	prev = local64_xchg(&event->hw.prev_count, now);
	local64_add(now - prev, &event->count);
	}

	static void h_gpci_event_start(struct perf_event *event, int flags)
	{
	local64_set(&event->hw.prev_count, h_gpci_get_value(event));
	}

	static void h_gpci_event_stop(struct perf_event *event, int flags)
	{
	h_gpci_event_update(event);
	}

	static int h_gpci_event_add(struct perf_event *event, int flags)
	{
	if (flags & PERF_EF_START)
	h_gpci_event_start(event, flags);

	return 0;
	}

	static int h_gpci_event_init(struct perf_event *event)
	{
	u64 count;
	u8 length;

	/* Not our event */
	if (event->attr.type != event->pmu->type)
	return -ENOENT;

	/* config2 is unused */
	if (event->attr.config2) {
	pr_devel("config2 set when reserved\n");
	return -EINVAL;
	}

	/* no branch sampling */
	if (has_branch_stack(event))
	return -EOPNOTSUPP;

	length = event_get_length(event);
	if (length < 1 \|\| length > 8) {
	pr_devel("length invalid\n");
	return -EINVAL;
	}

	/* last byte within the buffer? */
	if ((event_get_offset(event) + length) > HGPCI_MAX_DATA_BYTES) {
	pr_devel("request outside of buffer: %zu > %zu\n",
	(size_t)event_get_offset(event) + length,
	HGPCI_MAX_DATA_BYTES);
	return -EINVAL;
	}

	/* check if the request works... */
	if (single_gpci_request(event_get_request(event),
	event_get_starting_index(event),
	event_get_secondary_index(event),
	event_get_counter_info_version(event),
	event_get_offset(event),
	length,
	&count)) {
	pr_devel("gpci hcall failed\n");
	return -EINVAL;
	}

	return 0;
	}

	static struct pmu h_gpci_pmu = {
	.task_ctx_nr = perf_invalid_context,

	.name = "hv_gpci",
	.attr_groups = attr_groups,
	.event_init = h_gpci_event_init,
	.add = h_gpci_event_add,
	.del = h_gpci_event_stop,
	.start = h_gpci_event_start,
	.stop = h_gpci_event_stop,
	.read = h_gpci_event_update,
	.capabilities = PERF_PMU_CAP_NO_EXCLUDE,
	};

	static int ppc_hv_gpci_cpu_online(unsigned int cpu)
	{
	if (cpumask_empty(&hv_gpci_cpumask))
	cpumask_set_cpu(cpu, &hv_gpci_cpumask);

	return 0;
	}

	static int ppc_hv_gpci_cpu_offline(unsigned int cpu)
	{
	int target;

	/* Check if exiting cpu is used for collecting gpci events */
	if (!cpumask_test_and_clear_cpu(cpu, &hv_gpci_cpumask))
	return 0;

	/* Find a new cpu to collect gpci events */
	target = cpumask_last(cpu_active_mask);

	if (target < 0 \|\| target >= nr_cpu_ids) {
	pr_err("hv_gpci: CPU hotplug init failed\n");
	return -1;
	}

	/* Migrate gpci events to the new target */
	cpumask_set_cpu(target, &hv_gpci_cpumask);
	perf_pmu_migrate_context(&h_gpci_pmu, cpu, target);

	return 0;
	}

	static int hv_gpci_cpu_hotplug_init(void)
	{
	return cpuhp_setup_state(CPUHP_AP_PERF_POWERPC_HV_GPCI_ONLINE,
	"perf/powerpc/hv_gcpi:online",
	ppc_hv_gpci_cpu_online,
	ppc_hv_gpci_cpu_offline);
	}

	static int hv_gpci_init(void)
	{
	int r;
	unsigned long hret;
	struct hv_perf_caps caps;

	hv_gpci_assert_offsets_correct();

	if (!firmware_has_feature(FW_FEATURE_LPAR)) {
	pr_debug("not a virtualized system, not enabling\n");
	return -ENODEV;
	}

	hret = hv_perf_caps_get(&caps);
	if (hret) {
	pr_debug("could not obtain capabilities, not enabling, rc=%ld\n",
	hret);
	return -ENODEV;
	}

	/* init cpuhotplug */
	r = hv_gpci_cpu_hotplug_init();
	if (r)
	return r;

	/* sampling not supported */
	h_gpci_pmu.capabilities \|= PERF_PMU_CAP_NO_INTERRUPT;

	r = perf_pmu_register(&h_gpci_pmu, h_gpci_pmu.name, -1);
	if (r)
	return r;

	return 0;
	}

	device_initcall(hv_gpci_init);