diff options
| -rw-r--r-- | arch/powerpc/perf/hv-gpci.c | 294 |
1 files changed, 294 insertions, 0 deletions
diff --git a/arch/powerpc/perf/hv-gpci.c b/arch/powerpc/perf/hv-gpci.c new file mode 100644 index 000000000000..278ba7b9c2b5 --- /dev/null +++ b/arch/powerpc/perf/hv-gpci.c @@ -0,0 +1,294 @@ +/* + * Hypervisor supplied "gpci" ("get performance counter info") performance + * counter support + * + * Author: Cody P Schafer <cody@linux.vnet.ibm.com> + * Copyright 2014 IBM Corporation. + * + * 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. + */ + +#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 */ +EVENT_DEFINE_RANGE_FORMAT(starting_index, 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_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, +}; + +#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); +} + +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, + &interface_group, + NULL, +}; + +#define GPCI_MAX_DATA_BYTES \ + (1024 - sizeof(struct hv_get_perf_counter_info_params)) + +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 { + struct hv_get_perf_counter_info_params params; + uint8_t bytes[GPCI_MAX_DATA_BYTES]; + } __packed __aligned(sizeof(uint64_t)) arg = { + .params = { + .counter_request = cpu_to_be32(req), + .starting_index = cpu_to_be32(starting_index), + .secondary_index = cpu_to_be16(secondary_index), + .counter_info_version_in = version_in, + } + }; + + ret = plpar_hcall_norets(H_GET_PERF_COUNTER_INFO, + virt_to_phys(&arg), sizeof(arg)); + if (ret) { + pr_devel("hcall failed: 0x%lx\n", ret); + return ret; + } + + /* + * 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; + 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; + } + + /* unsupported modes and filters */ + if (event->attr.exclude_user || + event->attr.exclude_kernel || + event->attr.exclude_hv || + event->attr.exclude_idle || + event->attr.exclude_host || + event->attr.exclude_guest || + is_sampling_event(event)) /* no sampling */ + 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) > GPCI_MAX_DATA_BYTES) { + pr_devel("request outside of buffer: %zu > %zu\n", + (size_t)event_get_offset(event) + length, + GPCI_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 int h_gpci_event_idx(struct perf_event *event) +{ + 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, + .event_idx = h_gpci_event_idx, +}; + +static int hv_gpci_init(void) +{ + int r; + unsigned long hret; + struct hv_perf_caps caps; + + if (!firmware_has_feature(FW_FEATURE_LPAR)) { + pr_info("not a virtualized system, not enabling\n"); + return -ENODEV; + } + + hret = hv_perf_caps_get(&caps); + if (hret) { + pr_info("could not obtain capabilities, error 0x%80lx, not enabling\n", + hret); + return -ENODEV; + } + + r = perf_pmu_register(&h_gpci_pmu, h_gpci_pmu.name, -1); + if (r) + return r; + + return 0; +} + +device_initcall(hv_gpci_init); |