linux/arch/powerpc/perf/hv-gpci.c
Thomas Gleixner 2874c5fd28 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:32 -07:00

309 lines
7.6 KiB
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 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 DEVICE_ATTR_RO(kernel_version);
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_group interface_group = {
.name = "interface",
.attrs = interface_attrs,
};
static const struct attribute_group *attr_groups[] = {
&format_group,
&event_group,
&interface_group,
NULL,
};
#define HGPCI_REQ_BUFFER_SIZE 4096
#define HGPCI_MAX_DATA_BYTES \
(HGPCI_REQ_BUFFER_SIZE - sizeof(struct hv_get_perf_counter_info_params))
static DEFINE_PER_CPU(char, hv_gpci_reqb[HGPCI_REQ_BUFFER_SIZE]) __aligned(sizeof(uint64_t));
struct hv_gpci_request_buffer {
struct hv_get_perf_counter_info_params params;
uint8_t bytes[HGPCI_MAX_DATA_BYTES];
} __packed;
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 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;
}
/* 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);