// SPDX-License-Identifier: GPL-2.0-or-later /* * Hypervisor supplied "gpci" ("get performance counter info") performance * counter support * * Author: Cody P Schafer * Copyright 2014 IBM Corporation. */ #define pr_fmt(fmt) "hv-gpci: " fmt #include #include #include #include #include #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 |= (u64)(arg->bytes[i]) << ((length - 1 - (i - offset)) * 8); *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);