path: root/arch/powerpc/perf/hv-gpci.c

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

static struct attribute_group event_group = {
	.name  = "events",
	/* .attrs is set in init */
};

#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);
}

/* Interface attribute array index to store system information */
#define INTERFACE_PROCESSOR_BUS_TOPOLOGY_ATTR	6
#define INTERFACE_PROCESSOR_CONFIG_ATTR		7
#define INTERFACE_AFFINITY_DOMAIN_VIA_VP_ATTR	8
#define INTERFACE_AFFINITY_DOMAIN_VIA_DOM_ATTR	9
#define INTERFACE_AFFINITY_DOMAIN_VIA_PAR_ATTR	10
#define INTERFACE_NULL_ATTR			11

/* Counter request value to retrieve system information */
enum {
	PROCESSOR_BUS_TOPOLOGY,
	PROCESSOR_CONFIG,
	AFFINITY_DOMAIN_VIA_VP, /* affinity domain via virtual processor */
	AFFINITY_DOMAIN_VIA_DOM, /* affinity domain via domain */
	AFFINITY_DOMAIN_VIA_PAR, /* affinity domain via partition */
};

static int sysinfo_counter_request[] = {
	[PROCESSOR_BUS_TOPOLOGY] = 0xD0,
	[PROCESSOR_CONFIG] = 0x90,
	[AFFINITY_DOMAIN_VIA_VP] = 0xA0,
	[AFFINITY_DOMAIN_VIA_DOM] = 0xB0,
	[AFFINITY_DOMAIN_VIA_PAR] = 0xB1,
};

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

static unsigned long systeminfo_gpci_request(u32 req, u32 starting_index,
			u16 secondary_index, char *buf,
			size_t *n, struct hv_gpci_request_buffer *arg)
{
	unsigned long ret;
	size_t i, j;

	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);

	ret = plpar_hcall_norets(H_GET_PERF_COUNTER_INFO,
			virt_to_phys(arg), HGPCI_REQ_BUFFER_SIZE);

	/*
	 * ret value as 'H_PARAMETER' corresponds to 'GEN_BUF_TOO_SMALL',
	 * which means that the current buffer size cannot accommodate
	 * all the information and a partial buffer returned.
	 * hcall fails incase of ret value other than H_SUCCESS or H_PARAMETER.
	 *
	 * ret value as H_AUTHORITY implies that partition is not permitted to retrieve
	 * performance information, and required to set
	 * "Enable Performance Information Collection" option.
	 */
	if (ret ==</