// SPDX-License-Identifier: GPL-2.0 /* * RISC-V performance counter support. * * Copyright (C) 2021 Western Digital Corporation or its affiliates. * * This code is based on ARM perf event code which is in turn based on * sparc64 and x86 code. */ #define pr_fmt(fmt) "riscv-pmu-sbi: " fmt #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define ALT_SBI_PMU_OVERFLOW(__ovl) \ asm volatile(ALTERNATIVE_2( \ "csrr %0, " __stringify(CSR_SCOUNTOVF), \ "csrr %0, " __stringify(THEAD_C9XX_CSR_SCOUNTEROF), \ THEAD_VENDOR_ID, ERRATA_THEAD_PMU, \ CONFIG_ERRATA_THEAD_PMU, \ "csrr %0, " __stringify(ANDES_CSR_SCOUNTEROF), \ ANDES_VENDOR_ID, \ RISCV_ISA_VENDOR_EXT_XANDESPMU + RISCV_VENDOR_EXT_ALTERNATIVES_BASE, \ CONFIG_ANDES_CUSTOM_PMU) \ : "=r" (__ovl) : \ : "memory") #define ALT_SBI_PMU_OVF_CLEAR_PENDING(__irq_mask) \ asm volatile(ALTERNATIVE( \ "csrc " __stringify(CSR_IP) ", %0\n\t", \ "csrc " __stringify(ANDES_CSR_SLIP) ", %0\n\t", \ ANDES_VENDOR_ID, \ RISCV_ISA_VENDOR_EXT_XANDESPMU + RISCV_VENDOR_EXT_ALTERNATIVES_BASE, \ CONFIG_ANDES_CUSTOM_PMU) \ : : "r"(__irq_mask) \ : "memory") #define SYSCTL_NO_USER_ACCESS 0 #define SYSCTL_USER_ACCESS 1 #define SYSCTL_LEGACY 2 #define PERF_EVENT_FLAG_NO_USER_ACCESS BIT(SYSCTL_NO_USER_ACCESS) #define PERF_EVENT_FLAG_USER_ACCESS BIT(SYSCTL_USER_ACCESS) #define PERF_EVENT_FLAG_LEGACY BIT(SYSCTL_LEGACY) PMU_FORMAT_ATTR(event, "config:0-47"); PMU_FORMAT_ATTR(firmware, "config:63"); static bool sbi_v2_available; static DEFINE_STATIC_KEY_FALSE(sbi_pmu_snapshot_available); #define sbi_pmu_snapshot_available() \ static_branch_unlikely(&sbi_pmu_snapshot_available) static struct attribute *riscv_arch_formats_attr[] = { &format_attr_event.attr, &format_attr_firmware.attr, NULL, }; static struct attribute_group riscv_pmu_format_group = { .name = "format", .attrs = riscv_arch_formats_attr, }; static const struct attribute_group *riscv_pmu_attr_groups[] = { &riscv_pmu_format_group, NULL, }; /* Allow user mode access by default */ static int sysctl_perf_user_access __read_mostly = SYSCTL_USER_ACCESS; /* * RISC-V doesn't have heterogeneous harts yet. This need to be part of * per_cpu in case of harts with different pmu counters */ static union sbi_pmu_ctr_info *pmu_ctr_list; static bool riscv_pmu_use_irq; static unsigned int riscv_pmu_irq_num; static unsigned int riscv_pmu_irq_mask; static unsigned int riscv_pmu_irq; /* Cache the available counters in a bitmask */ static unsigned long cmask; struct sbi_pmu_event_data { union { union { struct hw_gen_event { uint32_t event_code:16; uint32_t event_type:4; uint32_t reserved:12; } hw_gen_event; struct hw_cache_event { uint32_t result_id:1; uint32_t op_id:2; uint32_t cache_id:13; uint32_t event_type:4; uint32_t reserved:12; } hw_cache_event; }; uint32_t event_idx; }; }; static struct sbi_pmu_event_data pmu_hw_event_map[] = { [PERF_COUNT_HW_CPU_CYCLES] = {.hw_gen_event = { SBI_PMU_HW_CPU_CYCLES, SBI_PMU_EVENT_TYPE_HW, 0}}, [PERF_COUNT_HW_INSTRUCTIONS] = {.hw_gen_event = { SBI_PMU_HW_INSTRUCTIONS, SBI_PMU_EVENT_TYPE_HW, 0}}, [PERF_COUNT_HW_CACHE_REFERENCES] = {.hw_gen_event = { SBI_PMU_HW_CACHE_REFERENCES, SBI_PMU_EVENT_TYPE_HW, 0}}, [PERF_COUNT_HW_CACHE_MISSES] = {.hw_gen_event = { SBI_PMU_HW_CACHE_MISSES, SBI_PMU_EVENT_TYPE_HW, 0}}, [PERF_COUNT_HW_BRANCH_INSTRUCTIONS] = {.hw_gen_event = { SBI_PMU_HW_BRANCH_INSTRUCTIONS, SBI_PMU_EVENT_TYPE_HW, 0}}, [PERF_COUNT_HW_BRANCH_MISSES] = {.hw_gen_event = { SBI_PMU_HW_BRANCH_MISSES, SBI_PMU_EVENT_TYPE_HW, 0}}, [PERF_COUNT_HW_BUS_CYCLES] = {.hw_gen_event = { SBI_PMU_HW_BUS_CYCLES, SBI_PMU_EVENT_TYPE_HW, 0}}, [PERF_COUNT_HW_STALLED_CYCLES_FRONTEND] = {.hw_gen_event = { SBI_PMU_HW_STALLED_CYCLES_FRONTEND, SBI_PMU_EVENT_TYPE_HW, 0}}, [PERF_COUNT_HW_STALLED_CYCLES_BACKEND] = {.hw_gen_event = { SBI_PMU_HW_STALLED_CYCLES_BACKEND, SBI_PMU_EVENT_TYPE_HW, 0}}, [PERF_COUNT_HW_REF_CPU_CYCLES] = {.hw_gen_event = { SBI_PMU_HW_REF_CPU_CYCLES, SBI_PMU_EVENT_TYPE_HW, 0}}, }; #define C(x) PERF_COUNT_HW_CACHE_##x static struct sbi_pmu_event_data pmu_cache_event_map[PERF_COUNT_HW_CACHE_MAX] [PERF_COUNT_HW_CACHE_OP_MAX] [PERF_COUNT_HW_CACHE_RESULT_MAX] = { [C(L1D)] = { [C(OP_READ)] = { [C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS), C(OP_READ), C(L1D), SBI_PMU_EVENT_TYPE_CACHE, 0}}, [C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS), C(OP_READ), C(L1D), SBI_PMU_EVENT_TYPE_CACHE, 0}}, }, [C(OP_WRITE)] = { [C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS), C(OP_WRITE), C(L1D), SBI_PMU_EVENT_TYPE_CACHE, 0}}, [C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS), C(OP_WRITE), C(L1D), SBI_PMU_EVENT_TYPE_CACHE, 0}}, }, [C(OP_PREFETCH)] = { [C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS), C(OP_PREFETCH), C(L1D), SBI_PMU_EVENT_TYPE_CACHE, 0}}, [C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS), C(OP_PREFETCH), C(L1D), SBI_PMU_EVENT_TYPE_CACHE, 0}}, }, }, [C(L1I)] = { [C(OP_READ)] = { [C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS), C(OP_READ), C(L1I), SBI_PMU_EVENT_TYPE_CACHE, 0}}, [C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS), C(OP_READ), C(L1I), SBI_PMU_EVENT_TYPE_CACHE, 0}}, }, [C(OP_WRITE)] = { [C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS), C(OP_WRITE), C(L1I), SBI_PMU_EVENT_TYPE_CACHE, 0}}, [C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS), C(OP_WRITE), C(L1I), SBI_PMU_EVENT_TYPE_CACHE, 0}}, }, [C(OP_PREFETCH)] = { [C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS), C(OP_PREFETCH), C(L1I), SBI_PMU_EVENT_TYPE_CACHE, 0}}, [C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS), C(OP_PREFETCH), C(L1I), SBI_PMU_EVENT_TYPE_CACHE, 0}}, }, }, [C(LL)] = { [C(OP_READ)] = { [C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS), C(OP_READ), C(LL), SBI_PMU_EVENT_TYPE_CACHE, 0}}, [C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS), C(OP_READ), C(LL), SBI_PMU_EVENT_TYPE_CACHE, 0}}, }, [C(OP_WRITE)] = { [C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS), C(OP_WRITE), C(LL), SBI_PMU_EVENT_TYPE_CACHE, 0}}, [C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS), C(OP_WRITE), C(LL), SBI_PMU_EVENT_TYPE_CACHE, 0}}, }, [C(OP_PREFETCH)] = { [C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS), C(OP_PREFETCH), C(LL), SBI_PMU_EVENT_TYPE_CACHE, 0}}, [C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS), C(OP_PREFETCH), C(LL), SBI_PMU_EVENT_TYPE_CACHE, 0}}, }, }, [C(DTLB)] = { [C(OP_READ)] = { [C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS), C(OP_READ), C(DTLB), SBI_PMU_EVENT_TYPE_CACHE, 0}}, [C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS), C(OP_READ), C(DTLB), SBI_PMU_EVENT_TYPE_CACHE, 0}}, }, [C(OP_WRITE)] = { [C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS), C(OP_WRITE), C(DTLB), SBI_PMU_EVENT_TYPE_CACHE, 0}}, [C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS), C(OP_WRITE), C(DTLB), SBI_PMU_EVENT_TYPE_CACHE, 0}}, }, [C(OP_PREFETCH)] = { [C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS), C(OP_PREFETCH), C(DTLB), SBI_PMU_EVENT_TYPE_CACHE, 0}}, [C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS), C(OP_PREFETCH), C(DTLB), SBI_PMU_EVENT_TYPE_CACHE, 0}}, }, }, [C(ITLB)] = { [C(OP_READ)] = { [C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS), C(OP_READ), C(ITLB), SBI_PMU_EVENT_TYPE_CACHE, 0}}, [C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS), C(OP_READ), C(ITLB), SBI_PMU_EVENT_TYPE_CACHE, 0}}, }, [C(OP_WRITE)] = { [C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS), C(OP_WRITE), C(ITLB), SBI_PMU_EVENT_TYPE_CACHE, 0}}, [C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS), C(OP_WRITE), C(ITLB), SBI_PMU_EVENT_TYPE_CACHE, 0}}, }, [C(OP_PREFETCH)] = { [C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS), C(OP_PREFETCH), C(ITLB), SBI_PMU_EVENT_TYPE_CACHE, 0}}, [C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS), C(OP_PREFETCH), C(ITLB), SBI_PMU_EVENT_TYPE_CACHE, 0}}, }, }, [C(BPU)] = { [C(OP_READ)] = { [C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS), C(OP_READ), C(BPU), SBI_PMU_EVENT_TYPE_CACHE, 0}}, [C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS), C(OP_READ), C(BPU), SBI_PMU_EVENT_TYPE_CACHE, 0}}, }, [C(OP_WRITE)] = { [C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS), C(OP_WRITE), C(BPU), SBI_PMU_EVENT_TYPE_CACHE, 0}}, [C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS), C(OP_WRITE), C(BPU), SBI_PMU_EVENT_TYPE_CACHE, 0}}, }, [C(OP_PREFETCH)] = { [C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS), C(OP_PREFETCH), C(BPU), SBI_PMU_EVENT_TYPE_CACHE, 0}}, [C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS), C(OP_PREFETCH), C(BPU), SBI_PMU_EVENT_TYPE_CACHE, 0}}, }, }, [C(NODE)] = { [C(OP_READ)] = { [C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS), C(OP_READ), C(NODE), SBI_PMU_EVENT_TYPE_CACHE, 0}}, [C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS), C(OP_READ), C(NODE), SBI_PMU_EVENT_TYPE_CACHE, 0}}, }, [C(OP_WRITE)] = { [C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS), C(OP_WRITE), C(NODE), SBI_PMU_EVENT_TYPE_CACHE, 0}}, [C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS), C(OP_WRITE), C(NODE), SBI_PMU_EVENT_TYPE_CACHE, 0}}, }, [C(OP_PREFETCH)] = { [C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS), C(OP_PREFETCH), C(NODE), SBI_PMU_EVENT_TYPE_CACHE, 0}}, [C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS), C(OP_PREFETCH), C(NODE), SBI_PMU_EVENT_TYPE_CACHE, 0}}, }, }, }; static void pmu_sbi_check_event(struct sbi_pmu_event_data *edata) { struct sbiret ret; ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_CFG_MATCH, 0, cmask, 0, edata->event_idx, 0, 0); if (!ret.error) { sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_STOP, ret.value, 0x1, SBI_PMU_STOP_FLAG_RESET, 0, 0, 0); } else if (ret.error == SBI_ERR_NOT_SUPPORTED) { /* This event cannot be monitored by any counter */ edata->event_idx = -EINVAL; } } static void pmu_sbi_check_std_events(struct work_struct *work) { for (int i = 0; i < ARRAY_SIZE(pmu_hw_event_map); i++) pmu_sbi_check_event(&pmu_hw_event_map[i]); for (int i = 0; i < ARRAY_SIZE(pmu_cache_event_map); i++) for (int j = 0; j < ARRAY_SIZE(pmu_cache_event_map[i]); j++) for (int k = 0; k < ARRAY_SIZE(pmu_cache_event_map[i][j]); k++) pmu_sbi_check_event(&pmu_cache_event_map[i][j][k]); } static DECLARE_WORK(check_std_events_work, pmu_sbi_check_std_events); static int pmu_sbi_ctr_get_width(int idx) { return pmu_ctr_list[idx].width; } static bool pmu_sbi_ctr_is_fw(int cidx) { union sbi_pmu_ctr_info *info; info = &pmu_ctr_list[cidx]; if (!info) return false; return (info->type == SBI_PMU_CTR_TYPE_FW) ? true : false; } /* * Returns the counter width of a programmable counter and number of hardware * counters. As we don't support heterogeneous CPUs yet, it is okay to just * return the counter width of the first programmable counter. */ int riscv_pmu_get_hpm_info(u32 *hw_ctr_width, u32 *num_hw_ctr) { int i; union sbi_pmu_ctr_info *info; u32 hpm_width = 0, hpm_count = 0; if (!cmask) return -EINVAL; for_each_set_bit(i, &cmask, RISCV_MAX_COUNTERS) { info = &pmu_ctr_list[i]; if (!info) continue; if (!hpm_width && info->csr != CSR_CYCLE && info->csr != CSR_INSTRET) hpm_width = info->width; if (info->type == SBI_PMU_CTR_TYPE_HW) hpm_count++; } *hw_ctr_width = hpm_width; *num_hw_ctr = hpm_count; return 0; } EXPORT_SYMBOL_GPL(riscv_pmu_get_hpm_info); static uint8_t pmu_sbi_csr_index(struct perf_event *event) { return pmu_ctr_list[event->hw.idx].csr - CSR_CYCLE; } static unsigned long pmu_sbi_get_filter_flags(struct perf_event *event) { unsigned long cflags = 0; bool guest_events = false; if (event->attr.config1 & RISCV_PMU_CONFIG1_GUEST_EVENTS) guest_events = true; if (event->attr.exclude_kernel) cflags |= guest_events ? SBI_PMU_CFG_FLAG_SET_VSINH : SBI_PMU_CFG_FLAG_SET_SINH; if (event->attr.exclude_user) cflags |= guest_events ? SBI_PMU_CFG_FLAG_SET_VUINH : SBI_PMU_CFG_FLAG_SET_UINH; if (guest_events && event->attr.exclude_hv) cflags |= SBI_PMU_CFG_FLAG_SET_SINH; if (event->attr.exclude_host) cflags |= SBI_PMU_CFG_FLAG_SET_UINH | SBI_PMU_CFG_FLAG_SET_SINH; if (event->attr.exclude_guest) cflags |= SBI_PMU_CFG_FLAG_SET_VSINH | SBI_PMU_CFG_FLAG_SET_VUINH; return cflags; } static int pmu_sbi_ctr_get_idx(struct perf_event *event) { struct hw_perf_event *hwc = &event->hw; struct riscv_pmu *rvpmu = to_riscv_pmu(event->pmu); struct cpu_hw_events *cpuc = this_cpu_ptr(rvpmu->hw_events); struct sbiret ret; int idx; uint64_t cbase = 0, cmask = rvpmu->cmask; unsigned long cflags = 0; cflags = pmu_sbi_get_filter_flags(event); /* * In legacy mode, we have to force the fixed counters for those events * but not in the user access mode as we want to use the other counters * that support sampling/filtering. */ if ((hwc->flags & PERF_EVENT_FLAG_LEGACY) && (event->attr.type == PERF_TYPE_HARDWARE)) { if (event->attr.config == PERF_COUNT_HW_CPU_CYCLES) { cflags |= SBI_PMU_CFG_FLAG_SKIP_MATCH; cmask = 1; } else if (event->attr.config == PERF_COUNT_HW_INSTRUCTIONS) { cflags |= SBI_PMU_CFG_FLAG_SKIP_MATCH; cmask = BIT(CSR_INSTRET - CSR_CYCLE); } } /* retrieve the available counter index */ #if defined(CONFIG_32BIT) ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_CFG_MATCH, cbase, cmask, cflags, hwc->event_base, hwc->config, hwc->config >> 32); #else ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_CFG_MATCH, cbase, cmask, cflags, hwc->event_base, hwc->config, 0); #endif if (ret.error) { pr_debug("Not able to find a counter for event %lx config %llx\n", hwc->event_base, hwc->config); return sbi_err_map_linux_errno(ret.error); } idx = ret.value; if (!test_bit(idx, &rvpmu->cmask) || !pmu_ctr_list[idx].value) return -ENOENT; /* Additional sanity check for the counter id */ if (pmu_sbi_ctr_is_fw(idx)) { if (!test_and_set_bit(idx, cpuc->used_fw_ctrs)) return idx; } else { if (!test_and_set_bit(idx, cpuc->used_hw_ctrs)) return idx; } return -ENOENT; } static void pmu_sbi_ctr_clear_idx(struct perf_event *event) { struct hw_perf_event *hwc = &event->hw; struct riscv_pmu *rvpmu = to_riscv_pmu(event->pmu); struct cpu_hw_events *cpuc = this_cpu_ptr(rvpmu->hw_events); int idx = hwc->idx; if (pmu_sbi_ctr_is_fw(idx)) clear_bit(idx, cpuc->used_fw_ctrs); else clear_bit(idx, cpuc->used_hw_ctrs); } static int pmu_event_find_cache(u64 config) { unsigned int cache_type, cache_op, cache_result, ret; cache_type = (config >> 0) & 0xff; if (cache_type >= PERF_COUNT_HW_CACHE_MAX) return -EINVAL; cache_op = (config >> 8) & 0xff; if (cache_op >= PERF_COUNT_HW_CACHE_OP_MAX) return -EINVAL; cache_result = (config >> 16) & 0xff; if (cache_result >= PERF_COUNT_HW_CACHE_RESULT_MAX) return -EINVAL; ret = pmu_cache_event_map[cache_type][cache_op][cache_result].event_idx; return ret; } static bool pmu_sbi_is_fw_event(struct perf_event *event) { u32 type = event->attr.type; u64 config = event->attr.config; if ((type == PERF_TYPE_RAW) && ((config >> 63) == 1)) return true; else return false; } static int pmu_sbi_event_map(struct perf_event *event, u64 *econfig) { u32 type = event->attr.type; u64 config = event->attr.config; int bSoftware; u64 raw_config_val; int ret; /* * Ensure we are finished checking standard hardware events for * validity before allowing userspace to configure any events. */ flush_work(&check_std_events_work); switch (type) { case PERF_TYPE_HARDWARE: if (config >= PERF_COUNT_HW_MAX) return -EINVAL; ret = pmu_hw_event_map[event->attr.config].event_idx; break; case PERF_TYPE_HW_CACHE: ret = pmu_event_find_cache(config); break; case PERF_TYPE_RAW: /* * As per SBI specification, the upper 16 bits must be unused for * a raw event. Use the MSB (63b) to distinguish between hardware * raw event and firmware events. */ bSoftware = config >> 63; raw_config_val = config & RISCV_PMU_RAW_EVENT_MASK; if (bSoftware) { ret = (raw_config_val & 0xFFFF) | (SBI_PMU_EVENT_TYPE_FW << 16); } else { ret = RISCV_PMU_RAW_EVENT_IDX; *econfig = raw_config_val; } break; default: ret = -EINVAL; break; } return ret; } static void pmu_sbi_snapshot_free(struct riscv_pmu *pmu) { int cpu; for_each_possible_cpu(cpu) { struct cpu_hw_events *cpu_hw_evt = per_cpu_ptr(pmu->hw_events, cpu); if (!cpu_hw_evt->snapshot_addr) continue; free_page((unsigned long)cpu_hw_evt->snapshot_addr); cpu_hw_evt->snapshot_addr = NULL; cpu_hw_evt->snapshot_addr_phys = 0; } } static int pmu_sbi_snapshot_alloc(struct riscv_pmu *pmu) { int cpu; struct page *snapshot_page; for_each_possible_cpu(cpu) { struct cpu_hw_events *cpu_hw_evt = per_cpu_ptr(pmu->hw_events, cpu); snapshot_page = alloc_page(GFP_ATOMIC | __GFP_ZERO); if (!snapshot_page) { pmu_sbi_snapshot_free(pmu); return -ENOMEM; } cpu_hw_evt->snapshot_addr = page_to_virt(snapshot_page); cpu_hw_evt->snapshot_addr_phys = page_to_phys(snapshot_page); } return 0; } static int pmu_sbi_snapshot_disable(void) { struct sbiret ret; ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_SNAPSHOT_SET_SHMEM, SBI_SHMEM_DISABLE, SBI_SHMEM_DISABLE, 0, 0, 0, 0); if (ret.error) { pr_warn("failed to disable snapshot shared memory\n"); return sbi_err_map_linux_errno(ret.error); } return 0; } static int pmu_sbi_snapshot_setup(struct riscv_pmu *pmu, int cpu) { struct cpu_hw_events *cpu_hw_evt; struct sbiret ret = {0}; cpu_hw_evt = per_cpu_ptr(pmu->hw_events, cpu); if (!cpu_hw_evt->snapshot_addr_phys) return -EINVAL; if (cpu_hw_evt->snapshot_set_done) return 0; if (IS_ENABLED(CONFIG_32BIT)) ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_SNAPSHOT_SET_SHMEM, cpu_hw_evt->snapshot_addr_phys, (u64)(cpu_hw_evt->snapshot_addr_phys) >> 32, 0, 0, 0, 0); else ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_SNAPSHOT_SET_SHMEM, cpu_hw_evt->snapshot_addr_phys, 0, 0, 0, 0, 0); /* Free up the snapshot area memory and fall back to SBI PMU calls without snapshot */ if (ret.error) { if (ret.error != SBI_ERR_NOT_SUPPORTED) pr_warn("pmu snapshot setup failed with error %ld\n", ret.error); return sbi_err_map_linux_errno(ret.error); } memset(cpu_hw_evt->snapshot_cval_shcopy, 0, sizeof(u64) * RISCV_MAX_COUNTERS); cpu_hw_evt->snapshot_set_done = true; return 0; } static u64 pmu_sbi_ctr_read(struct perf_event *event) { struct hw_perf_event *hwc = &event->hw; int idx = hwc->idx; struct sbiret ret; u64 val = 0; struct riscv_pmu *pmu = to_riscv_pmu(event->pmu); struct cpu_hw_events *cpu_hw_evt = this_cpu_ptr(pmu->hw_events); struct riscv_pmu_snapshot_data *sdata = cpu_hw_evt->snapshot_addr; union sbi_pmu_ctr_info info = pmu_ctr_list[idx]; /* Read the value from the shared memory directly only if counter is stopped */ if (sbi_pmu_snapshot_available() && (hwc->state & PERF_HES_STOPPED)) { val = sdata->ctr_values[idx]; return val; } if (pmu_sbi_is_fw_event(event)) { ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_FW_READ, hwc->idx, 0, 0, 0, 0, 0); if (ret.error) return 0; val = ret.value; if (IS_ENABLED(CONFIG_32BIT) && sbi_v2_available && info.width >= 32) { ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_FW_READ_HI, hwc->idx, 0, 0, 0, 0, 0); if (!ret.error) val |= ((u64)ret.value << 32); else WARN_ONCE(1, "Unable to read upper 32 bits of firmware counter error: %ld\n", ret.error); } } else { val = riscv_pmu_ctr_read_csr(info.csr); if (IS_ENABLED(CONFIG_32BIT)) val |= ((u64)riscv_pmu_ctr_read_csr(info.csr + 0x80)) << 32; } return val; } static void pmu_sbi_set_scounteren(void *arg) { struct perf_event *event = (struct perf_event *)arg; if (event->hw.idx != -1) csr_write(CSR_SCOUNTEREN, csr_read(CSR_SCOUNTEREN) | BIT(pmu_sbi_csr_index(event))); } static void pmu_sbi_reset_scounteren(void *arg) { struct perf_event *event = (struct perf_event *)arg; if (event->hw.idx != -1) csr_write(CSR_SCOUNTEREN, csr_read(CSR_SCOUNTEREN) & ~BIT(pmu_sbi_csr_index(event))); } static void pmu_sbi_ctr_start(struct perf_event *event, u64 ival) { struct sbiret ret; struct hw_perf_event *hwc = &event->hw; unsigned long flag = SBI_PMU_START_FLAG_SET_INIT_VALUE; /* There is no benefit setting SNAPSHOT FLAG for a single counter */ #if defined(CONFIG_32BIT) ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_START, hwc->idx, 1, flag, ival, ival >> 32, 0); #else ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_START, hwc->idx, 1, flag, ival, 0, 0); #endif if (ret.error && (ret.error != SBI_ERR_ALREADY_STARTED)) pr_err("Starting counter idx %d failed with error %d\n", hwc->idx, sbi_err_map_linux_errno(ret.error)); if ((hwc->flags & PERF_EVENT_FLAG_USER_ACCESS) && (hwc->flags & PERF_EVENT_FLAG_USER_READ_CNT)) pmu_sbi_set_scounteren((void *)event); } static void pmu_sbi_ctr_stop(struct perf_event *event, unsigned long flag) { struct sbiret ret; struct hw_perf_event *hwc = &event->hw; struct riscv_pmu *pmu = to_riscv_pmu(event->pmu); struct cpu_hw_events *cpu_hw_evt = this_cpu_ptr(pmu->hw_events); struct riscv_pmu_snapshot_data *sdata = cpu_hw_evt->snapshot_addr; if ((hwc->flags & PERF_EVENT_FLAG_USER_ACCESS) && (hwc->flags & PERF_EVENT_FLAG_USER_READ_CNT)) pmu_sbi_reset_scounteren((void *)event); if (sbi_pmu_snapshot_available()) flag |= SBI_PMU_STOP_FLAG_TAKE_SNAPSHOT; ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_STOP, hwc->idx, 1, flag, 0, 0, 0); if (!ret.error && sbi_pmu_snapshot_available()) { /* * The counter snapshot is based on the index base specified by hwc->idx. * The actual counter value is updated in shared memory at index 0 when counter * mask is 0x01. To ensure accurate counter values, it's necessary to transfer * the counter value to shared memory. However, if hwc->idx is zero, the counter * value is already correctly updated in shared memory, requiring no further * adjustment. */ if (hwc->idx > 0) { sdata->ctr_values[hwc->idx] = sdata->ctr_values[0]; sdata->ctr_values[0] = 0; } } else if (ret.error && (ret.error != SBI_ERR_ALREADY_STOPPED) && flag != SBI_PMU_STOP_FLAG_RESET) { pr_err("Stopping counter idx %d failed with error %d\n", hwc->idx, sbi_err_map_linux_errno(ret.error)); } } static int pmu_sbi_find_num_ctrs(void) { struct sbiret ret; ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_NUM_COUNTERS, 0, 0, 0, 0, 0, 0); if (!ret.error) return ret.value; else return sbi_err_map_linux_errno(ret.error); } static int pmu_sbi_get_ctrinfo(int nctr, unsigned long *mask) { struct sbiret ret; int i, num_hw_ctr = 0, num_fw_ctr = 0; union sbi_pmu_ctr_info cinfo; pmu_ctr_list = kcalloc(nctr, sizeof(*pmu_ctr_list), GFP_KERNEL); if (!pmu_ctr_list) return -ENOMEM; for (i = 0; i < nctr; i++) { ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_GET_INFO, i, 0, 0, 0, 0, 0); if (ret.error) /* The logical counter ids are not expected to be contiguous */ continue; *mask |= BIT(i); cinfo.value = ret.value; if (cinfo.type == SBI_PMU_CTR_TYPE_FW) num_fw_ctr++; else num_hw_ctr++; pmu_ctr_list[i].value = cinfo.value; } pr_info("%d firmware and %d hardware counters\n", num_fw_ctr, num_hw_ctr); return 0; } static inline void pmu_sbi_stop_all(struct riscv_pmu *pmu) { /* * No need to check the error because we are disabling all the counters * which may include counters that are not enabled yet. */ sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_STOP, 0, pmu->cmask, SBI_PMU_STOP_FLAG_RESET, 0, 0, 0); } static inline void pmu_sbi_stop_hw_ctrs(struct riscv_pmu *pmu) { struct cpu_hw_events *cpu_hw_evt = this_cpu_ptr(pmu->hw_events); struct riscv_pmu_snapshot_data *sdata = cpu_hw_evt->snapshot_addr; unsigned long flag = 0; int i, idx; struct sbiret ret; u64 temp_ctr_overflow_mask = 0; if (sbi_pmu_snapshot_available()) flag = SBI_PMU_STOP_FLAG_TAKE_SNAPSHOT; /* Reset the shadow copy to avoid save/restore any value from previous overflow */ memset(cpu_hw_evt->snapshot_cval_shcopy, 0, sizeof(u64) * RISCV_MAX_COUNTERS); for (i = 0; i < BITS_TO_LONGS(RISCV_MAX_COUNTERS); i++) { /* No need to check the error here as we can't do anything about the error */ ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_STOP, i * BITS_PER_LONG, cpu_hw_evt->used_hw_ctrs[i], flag, 0, 0, 0); if (!ret.error && sbi_pmu_snapshot_available()) { /* Save the counter values to avoid clobbering */ for_each_set_bit(idx, &cpu_hw_evt->used_hw_ctrs[i], BITS_PER_LONG) cpu_hw_evt->snapshot_cval_shcopy[i * BITS_PER_LONG + idx] = sdata->ctr_values[idx]; /* Save the overflow mask to avoid clobbering */ temp_ctr_overflow_mask |= sdata->ctr_overflow_mask << (i * BITS_PER_LONG); } } /* Restore the counter values to the shared memory for used hw counters */ if (sbi_pmu_snapshot_available()) { for_each_set_bit(idx, cpu_hw_evt->used_hw_ctrs, RISCV_MAX_COUNTERS) sdata->ctr_values[idx] = cpu_hw_evt->snapshot_cval_shcopy[idx]; if (temp_ctr_overflow_mask) sdata->ctr_overflow_mask = temp_ctr_overflow_mask; } } /* * This function starts all the used counters in two step approach. * Any counter that did not overflow can be start in a single step * while the overflowed counters need to be started with updated initialization * value. */ static inline void pmu_sbi_start_ovf_ctrs_sbi(struct cpu_hw_events *cpu_hw_evt, u64 ctr_ovf_mask) { int idx = 0, i; struct perf_event *event; unsigned long flag = SBI_PMU_START_FLAG_SET_INIT_VALUE; unsigned long ctr_start_mask = 0; uint64_t max_period; struct hw_perf_event *hwc; u64 init_val = 0; for (i = 0; i < BITS_TO_LONGS(RISCV_MAX_COUNTERS); i++) { ctr_start_mask = cpu_hw_evt->used_hw_ctrs[i] & ~ctr_ovf_mask; /* Start all the counters that did not overflow in a single shot */ sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_START, i * BITS_PER_LONG, ctr_start_mask, 0, 0, 0, 0); } /* Reinitialize and start all the counter that overflowed */ while (ctr_ovf_mask) { if (ctr_ovf_mask & 0x01) { event = cpu_hw_evt->events[idx]; hwc = &event->hw; max_period = riscv_pmu_ctr_get_width_mask(event); init_val = local64_read(&hwc->prev_count) & max_period; #if defined(CONFIG_32BIT) sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_START, idx, 1, flag, init_val, init_val >> 32, 0); #else sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_START, idx, 1, flag, init_val, 0, 0); #endif perf_event_update_userpage(event); } ctr_ovf_mask = ctr_ovf_mask >> 1; idx++; } } static inline void pmu_sbi_start_ovf_ctrs_snapshot(struct cpu_hw_events *cpu_hw_evt, u64 ctr_ovf_mask) { int i, idx = 0; struct perf_event *event; unsigned long flag = SBI_PMU_START_FLAG_INIT_SNAPSHOT; u64 max_period, init_val = 0; struct hw_perf_event *hwc; struct riscv_pmu_snapshot_data *sdata = cpu_hw_evt->snapshot_addr; for_each_set_bit(idx, cpu_hw_evt->used_hw_ctrs, RISCV_MAX_COUNTERS) { if (ctr_ovf_mask & BIT(idx)) { event = cpu_hw_evt->events[idx]; hwc = &event->hw; max_period = riscv_pmu_ctr_get_width_mask(event); init_val = local64_read(&hwc->prev_count) & max_period; cpu_hw_evt->snapshot_cval_shcopy[idx] = init_val; } /* * We do not need to update the non-overflow counters the previous * value should have been there already. */ } for (i = 0; i < BITS_TO_LONGS(RISCV_MAX_COUNTERS); i++) { /* Restore the counter values to relative indices for used hw counters */ for_each_set_bit(idx, &cpu_hw_evt->used_hw_ctrs[i], BITS_PER_LONG) sdata->ctr_values[idx] = cpu_hw_evt->snapshot_cval_shcopy[idx + i * BITS_PER_LONG]; /* Start all the counters in a single shot */ sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_START, idx * BITS_PER_LONG, cpu_hw_evt->used_hw_ctrs[i], flag, 0, 0, 0); } } static void pmu_sbi_start_overflow_mask(struct riscv_pmu *pmu, u64 ctr_ovf_mask) { struct cpu_hw_events *cpu_hw_evt = this_cpu_ptr(pmu->hw_events); if (sbi_pmu_snapshot_available()) pmu_sbi_start_ovf_ctrs_snapshot(cpu_hw_evt, ctr_ovf_mask); else pmu_sbi_start_ovf_ctrs_sbi(cpu_hw_evt, ctr_ovf_mask); } static irqreturn_t pmu_sbi_ovf_handler(int irq, void *dev) { struct perf_sample_data data; struct pt_regs *regs; struct hw_perf_event *hw_evt; union sbi_pmu_ctr_info *info; int lidx, hidx, fidx; struct riscv_pmu *pmu; struct perf_event *event; u64 overflow; u64 overflowed_ctrs = 0; struct cpu_hw_events *cpu_hw_evt = dev; u64 start_clock = sched_clock(); struct riscv_pmu_snapshot_data *sdata = cpu_hw_evt->snapshot_addr; if (WARN_ON_ONCE(!cpu_hw_evt)) return IRQ_NONE; /* Firmware counter don't support overflow yet */ fidx = find_first_bit(cpu_hw_evt->used_hw_ctrs, RISCV_MAX_COUNTERS); if (fidx == RISCV_MAX_COUNTERS) { csr_clear(CSR_SIP, BIT(riscv_pmu_irq_num)); return IRQ_NONE; } event = cpu_hw_evt->events[fidx]; if (!event) { ALT_SBI_PMU_OVF_CLEAR_PENDING(riscv_pmu_irq_mask); return IRQ_NONE; } pmu = to_riscv_pmu(event->pmu); pmu_sbi_stop_hw_ctrs(pmu); /* Overflow status register should only be read after counter are stopped */ if (sbi_pmu_snapshot_available()) overflow = sdata->ctr_overflow_mask; else ALT_SBI_PMU_OVERFLOW(overflow); /* * Overflow interrupt pending bit should only be cleared after stopping * all the counters to avoid any race condition. */ ALT_SBI_PMU_OVF_CLEAR_PENDING(riscv_pmu_irq_mask); /* No overflow bit is set */ if (!overflow) return IRQ_NONE; regs = get_irq_regs(); for_each_set_bit(lidx, cpu_hw_evt->used_hw_ctrs, RISCV_MAX_COUNTERS) { struct perf_event *event = cpu_hw_evt->events[lidx]; /* Skip if invalid event or user did not request a sampling */ if (!event || !is_sampling_event(event)) continue; info = &pmu_ctr_list[lidx]; /* Do a sanity check */ if (!info || info->type != SBI_PMU_CTR_TYPE_HW) continue; if (sbi_pmu_snapshot_available()) /* SBI implementation already updated the logical indicies */ hidx = lidx; else /* compute hardware counter index */ hidx = info->csr - CSR_CYCLE; /* check if the corresponding bit is set in sscountovf or overflow mask in shmem */ if (!(overflow & BIT(hidx))) continue; /* * Keep a track of overflowed counters so that they can be started * with updated initial value. */ overflowed_ctrs |= BIT(lidx); hw_evt = &event->hw; /* Update the event states here so that we know the state while reading */ hw_evt->state |= PERF_HES_STOPPED; riscv_pmu_event_update(event); hw_evt->state |= PERF_HES_UPTODATE; perf_sample_data_init(&data, 0, hw_evt->last_period); if (riscv_pmu_event_set_period(event)) { /* * Unlike other ISAs, RISC-V don't have to disable interrupts * to avoid throttling here. As per the specification, the * interrupt remains disabled until the OF bit is set. * Interrupts are enabled again only during the start. * TODO: We will need to stop the guest counters once * virtualization support is added. */ perf_event_overflow(event, &data, regs); } /* Reset the state as we are going to start the counter after the loop */ hw_evt->state = 0; } pmu_sbi_start_overflow_mask(pmu, overflowed_ctrs); perf_sample_event_took(sched_clock() - start_clock); return IRQ_HANDLED; } static int pmu_sbi_starting_cpu(unsigned int cpu, struct hlist_node *node) { struct riscv_pmu *pmu = hlist_entry_safe(node, struct riscv_pmu, node); struct cpu_hw_events *cpu_hw_evt = this_cpu_ptr(pmu->hw_events); /* * We keep enabling userspace access to CYCLE, TIME and INSTRET via the * legacy option but that will be removed in the future. */ if (sysctl_perf_user_access == SYSCTL_LEGACY) csr_write(CSR_SCOUNTEREN, 0x7); else csr_write(CSR_SCOUNTEREN, 0x2); /* Stop all the counters so that they can be enabled from perf */ pmu_sbi_stop_all(pmu); if (riscv_pmu_use_irq) { cpu_hw_evt->irq = riscv_pmu_irq; ALT_SBI_PMU_OVF_CLEAR_PENDING(riscv_pmu_irq_mask); enable_percpu_irq(riscv_pmu_irq, IRQ_TYPE_NONE); } if (sbi_pmu_snapshot_available()) return pmu_sbi_snapshot_setup(pmu, cpu); return 0; } static int pmu_sbi_dying_cpu(unsigned int cpu, struct hlist_node *node) { if (riscv_pmu_use_irq) { disable_percpu_irq(riscv_pmu_irq); } /* Disable all counters access for user mode now */ csr_write(CSR_SCOUNTEREN, 0x0); if (sbi_pmu_snapshot_available()) return pmu_sbi_snapshot_disable(); return 0; } static int pmu_sbi_setup_irqs(struct riscv_pmu *pmu, struct platform_device *pdev) { int ret; struct cpu_hw_events __percpu *hw_events = pmu->hw_events; struct irq_domain *domain = NULL; if (riscv_isa_extension_available(NULL, SSCOFPMF)) { riscv_pmu_irq_num = RV_IRQ_PMU; riscv_pmu_use_irq = true; } else if (IS_ENABLED(CONFIG_ERRATA_THEAD_PMU) && riscv_cached_mvendorid(0) == THEAD_VENDOR_ID && riscv_cached_marchid(0) == 0 && riscv_cached_mimpid(0) == 0) { riscv_pmu_irq_num = THEAD_C9XX_RV_IRQ_PMU; riscv_pmu_use_irq = true; } else if (riscv_has_vendor_extension_unlikely(ANDES_VENDOR_ID, RISCV_ISA_VENDOR_EXT_XANDESPMU) && IS_ENABLED(CONFIG_ANDES_CUSTOM_PMU)) { riscv_pmu_irq_num = ANDES_SLI_CAUSE_BASE + ANDES_RV_IRQ_PMOVI; riscv_pmu_use_irq = true; } riscv_pmu_irq_mask = BIT(riscv_pmu_irq_num % BITS_PER_LONG); if (!riscv_pmu_use_irq) return -EOPNOTSUPP; domain = irq_find_matching_fwnode(riscv_get_intc_hwnode(), DOMAIN_BUS_ANY); if (!domain) { pr_err("Failed to find INTC IRQ root domain\n"); return -ENODEV; } riscv_pmu_irq = irq_create_mapping(domain, riscv_pmu_irq_num); if (!riscv_pmu_irq) { pr_err("Failed to map PMU interrupt for node\n"); return -ENODEV; } ret = request_percpu_irq(riscv_pmu_irq, pmu_sbi_ovf_handler, "riscv-pmu", hw_events); if (ret) { pr_err("registering percpu irq failed [%d]\n", ret); return ret; } return 0; } #ifdef CONFIG_CPU_PM static int riscv_pm_pmu_notify(struct notifier_block *b, unsigned long cmd, void *v) { struct riscv_pmu *rvpmu = container_of(b, struct riscv_pmu, riscv_pm_nb); struct cpu_hw_events *cpuc = this_cpu_ptr(rvpmu->hw_events); int enabled = bitmap_weight(cpuc->used_hw_ctrs, RISCV_MAX_COUNTERS); struct perf_event *event; int idx; if (!enabled) return NOTIFY_OK; for (idx = 0; idx < RISCV_MAX_COUNTERS; idx++) { event = cpuc->events[idx]; if (!event) continue; switch (cmd) { case CPU_PM_ENTER: /* * Stop and update the counter */ riscv_pmu_stop(event, PERF_EF_UPDATE); break; case CPU_PM_EXIT: case CPU_PM_ENTER_FAILED: /* * Restore and enable the counter. */ riscv_pmu_start(event, PERF_EF_RELOAD); break; default: break; } } return NOTIFY_OK; } static int riscv_pm_pmu_register(struct riscv_pmu *pmu) { pmu->riscv_pm_nb.notifier_call = riscv_pm_pmu_notify; return cpu_pm_register_notifier(&pmu->riscv_pm_nb); } static void riscv_pm_pmu_unregister(struct riscv_pmu *pmu) { cpu_pm_unregister_notifier(&pmu->riscv_pm_nb); } #else static inline int riscv_pm_pmu_register(struct riscv_pmu *pmu) { return 0; } static inline void riscv_pm_pmu_unregister(struct riscv_pmu *pmu) { } #endif static void riscv_pmu_destroy(struct riscv_pmu *pmu) { if (sbi_v2_available) { if (sbi_pmu_snapshot_available()) { pmu_sbi_snapshot_disable(); pmu_sbi_snapshot_free(pmu); } } riscv_pm_pmu_unregister(pmu); cpuhp_state_remove_instance(CPUHP_AP_PERF_RISCV_STARTING, &pmu->node); } static void pmu_sbi_event_init(struct perf_event *event) { /* * The permissions are set at event_init so that we do not depend * on the sysctl value that can change. */ if (sysctl_perf_user_access == SYSCTL_NO_USER_ACCESS) event->hw.flags |= PERF_EVENT_FLAG_NO_USER_ACCESS; else if (sysctl_perf_user_access == SYSCTL_USER_ACCESS) event->hw.flags |= PERF_EVENT_FLAG_USER_ACCESS; else event->hw.flags |= PERF_EVENT_FLAG_LEGACY; } static void pmu_sbi_event_mapped(struct perf_event *event, struct mm_struct *mm) { if (event->hw.flags & PERF_EVENT_FLAG_NO_USER_ACCESS) return; if (event->hw.flags & PERF_EVENT_FLAG_LEGACY) { if (event->attr.config != PERF_COUNT_HW_CPU_CYCLES && event->attr.config != PERF_COUNT_HW_INSTRUCTIONS) { return; } } /* * The user mmapped the event to directly access it: this is where * we determine based on sysctl_perf_user_access if we grant userspace * the direct access to this event. That means that within the same * task, some events may be directly accessible and some other may not, * if the user changes the value of sysctl_perf_user_accesss in the * meantime. */ event->hw.flags |= PERF_EVENT_FLAG_USER_READ_CNT; /* * We must enable userspace access *before* advertising in the user page * that it is possible to do so to avoid any race. * And we must notify all cpus here because threads that currently run * on other cpus will try to directly access the counter too without * calling pmu_sbi_ctr_start. */ if (event->hw.flags & PERF_EVENT_FLAG_USER_ACCESS) on_each_cpu_mask(mm_cpumask(mm), pmu_sbi_set_scounteren, (void *)event, 1); } static void pmu_sbi_event_unmapped(struct perf_event *event, struct mm_struct *mm) { if (event->hw.flags & PERF_EVENT_FLAG_NO_USER_ACCESS) return; if (event->hw.flags & PERF_EVENT_FLAG_LEGACY) { if (event->attr.config != PERF_COUNT_HW_CPU_CYCLES && event->attr.config != PERF_COUNT_HW_INSTRUCTIONS) { return; } } /* * Here we can directly remove user access since the user does not have * access to the user page anymore so we avoid the racy window where the * user could have read cap_user_rdpmc to true right before we disable * it. */ event->hw.flags &= ~PERF_EVENT_FLAG_USER_READ_CNT; if (event->hw.flags & PERF_EVENT_FLAG_USER_ACCESS) on_each_cpu_mask(mm_cpumask(mm), pmu_sbi_reset_scounteren, (void *)event, 1); } static void riscv_pmu_update_counter_access(void *info) { if (sysctl_perf_user_access == SYSCTL_LEGACY) csr_write(CSR_SCOUNTEREN, 0x7); else csr_write(CSR_SCOUNTEREN, 0x2); } static int riscv_pmu_proc_user_access_handler(const struct ctl_table *table, int write, void *buffer, size_t *lenp, loff_t *ppos) { int prev = sysctl_perf_user_access; int ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos); /* * Test against the previous value since we clear SCOUNTEREN when * sysctl_perf_user_access is set to SYSCTL_USER_ACCESS, but we should * not do that if that was already the case. */ if (ret || !write || prev == sysctl_perf_user_access) return ret; on_each_cpu(riscv_pmu_update_counter_access, NULL, 1); return 0; } static struct ctl_table sbi_pmu_sysctl_table[] = { { .procname = "perf_user_access", .data = &sysctl_perf_user_access, .maxlen = sizeof(unsigned int), .mode = 0644, .proc_handler = riscv_pmu_proc_user_access_handler, .extra1 = SYSCTL_ZERO, .extra2 = SYSCTL_TWO, }, }; static int pmu_sbi_device_probe(struct platform_device *pdev) { struct riscv_pmu *pmu = NULL; int ret = -ENODEV; int num_counters; pr_info("SBI PMU extension is available\n"); pmu = riscv_pmu_alloc(); if (!pmu) return -ENOMEM; num_counters = pmu_sbi_find_num_ctrs(); if (num_counters < 0) { pr_err("SBI PMU extension doesn't provide any counters\n"); goto out_free; } /* It is possible to get from SBI more than max number of counters */ if (num_counters > RISCV_MAX_COUNTERS) { num_counters = RISCV_MAX_COUNTERS; pr_info("SBI returned more than maximum number of counters. Limiting the number of counters to %d\n", num_counters); } /* cache all the information about counters now */ if (pmu_sbi_get_ctrinfo(num_counters, &cmask)) goto out_free; ret = pmu_sbi_setup_irqs(pmu, pdev); if (ret < 0) { pr_info("Perf sampling/filtering is not supported as sscof extension is not available\n"); pmu->pmu.capabilities |= PERF_PMU_CAP_NO_INTERRUPT; pmu->pmu.capabilities |= PERF_PMU_CAP_NO_EXCLUDE; } pmu->pmu.attr_groups = riscv_pmu_attr_groups; pmu->pmu.parent = &pdev->dev; pmu->cmask = cmask; pmu->ctr_start = pmu_sbi_ctr_start; pmu->ctr_stop = pmu_sbi_ctr_stop; pmu->event_map = pmu_sbi_event_map; pmu->ctr_get_idx = pmu_sbi_ctr_get_idx; pmu->ctr_get_width = pmu_sbi_ctr_get_width; pmu->ctr_clear_idx = pmu_sbi_ctr_clear_idx; pmu->ctr_read = pmu_sbi_ctr_read; pmu->event_init = pmu_sbi_event_init; pmu->event_mapped = pmu_sbi_event_mapped; pmu->event_unmapped = pmu_sbi_event_unmapped; pmu->csr_index = pmu_sbi_csr_index; ret = riscv_pm_pmu_register(pmu); if (ret) goto out_unregister; ret = perf_pmu_register(&pmu->pmu, "cpu", PERF_TYPE_RAW); if (ret) goto out_unregister; /* SBI PMU Snapsphot is only available in SBI v2.0 */ if (sbi_v2_available) { int cpu; ret = pmu_sbi_snapshot_alloc(pmu); if (ret) goto out_unregister; cpu = get_cpu(); ret = pmu_sbi_snapshot_setup(pmu, cpu); if (ret) { /* Snapshot is an optional feature. Continue if not available */ pmu_sbi_snapshot_free(pmu); } else { pr_info("SBI PMU snapshot detected\n"); /* * We enable it once here for the boot cpu. If snapshot shmem setup * fails during cpu hotplug process, it will fail to start the cpu * as we can not handle hetergenous PMUs with different snapshot * capability. */ static_branch_enable(&sbi_pmu_snapshot_available); } put_cpu(); } register_sysctl("kernel", sbi_pmu_sysctl_table); ret = cpuhp_state_add_instance(CPUHP_AP_PERF_RISCV_STARTING, &pmu->node); if (ret) goto out_unregister; /* Asynchronously check which standard events are available */ schedule_work(&check_std_events_work); return 0; out_unregister: riscv_pmu_destroy(pmu); out_free: kfree(pmu); return ret; } static struct platform_driver pmu_sbi_driver = { .probe = pmu_sbi_device_probe, .driver = { .name = RISCV_PMU_SBI_PDEV_NAME, }, }; static int __init pmu_sbi_devinit(void) { int ret; struct platform_device *pdev; if (sbi_spec_version < sbi_mk_version(0, 3) || !sbi_probe_extension(SBI_EXT_PMU)) { return 0; } if (sbi_spec_version >= sbi_mk_version(2, 0)) sbi_v2_available = true; ret = cpuhp_setup_state_multi(CPUHP_AP_PERF_RISCV_STARTING, "perf/riscv/pmu:starting", pmu_sbi_starting_cpu, pmu_sbi_dying_cpu); if (ret) { pr_err("CPU hotplug notifier could not be registered: %d\n", ret); return ret; } ret = platform_driver_register(&pmu_sbi_driver); if (ret) return ret; pdev = platform_device_register_simple(RISCV_PMU_SBI_PDEV_NAME, -1, NULL, 0); if (IS_ERR(pdev)) { platform_driver_unregister(&pmu_sbi_driver); return PTR_ERR(pdev); } /* Notify legacy implementation that SBI pmu is available*/ riscv_pmu_legacy_skip_init(); return ret; } device_initcall(pmu_sbi_devinit)