diff options
Diffstat (limited to 'drivers/perf/riscv_pmu_sbi.c')
| -rw-r--r-- | drivers/perf/riscv_pmu_sbi.c | 1135 |
1 files changed, 1135 insertions, 0 deletions
diff --git a/drivers/perf/riscv_pmu_sbi.c b/drivers/perf/riscv_pmu_sbi.c new file mode 100644 index 0000000000..cd8a2b9efd --- /dev/null +++ b/drivers/perf/riscv_pmu_sbi.c @@ -0,0 +1,1135 @@ +// 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 <linux/mod_devicetable.h> +#include <linux/perf/riscv_pmu.h> +#include <linux/platform_device.h> +#include <linux/irq.h> +#include <linux/irqdomain.h> +#include <linux/of_irq.h> +#include <linux/of.h> +#include <linux/cpu_pm.h> +#include <linux/sched/clock.h> + +#include <asm/errata_list.h> +#include <asm/sbi.h> +#include <asm/hwcap.h> + +#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 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; + +/* 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 const 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 const 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 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) { + 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 = 1UL << (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; + + 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 u64 pmu_sbi_ctr_read(struct perf_event *event) +{ + struct hw_perf_event *hwc = &event->hw; + int idx = hwc->idx; + struct sbiret ret; + union sbi_pmu_ctr_info info; + u64 val = 0; + + 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) + val = ret.value; + } else { + info = pmu_ctr_list[idx]; + val = riscv_pmu_ctr_read_csr(info.csr); + if (IS_ENABLED(CONFIG_32BIT)) + val = ((u64)riscv_pmu_ctr_read_csr(info.csr + 0x80)) << 31 | val; + } + + 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) | (1 << 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) & ~(1 << 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; + +#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; + + if ((hwc->flags & PERF_EVENT_FLAG_USER_ACCESS) && + (hwc->flags & PERF_EVENT_FLAG_USER_READ_CNT)) + pmu_sbi_reset_scounteren((void *)event); + + ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_STOP, hwc->idx, 1, flag, 0, 0, 0); + 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, 0, 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); + + /* No need to check the error here as we can't do anything about the error */ + sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_STOP, 0, + cpu_hw_evt->used_hw_ctrs[0], 0, 0, 0, 0); +} + +/* + * 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_overflow_mask(struct riscv_pmu *pmu, + unsigned long ctr_ovf_mask) +{ + int idx = 0; + struct cpu_hw_events *cpu_hw_evt = this_cpu_ptr(pmu->hw_events); + 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; + + ctr_start_mask = cpu_hw_evt->used_hw_ctrs[0] & ~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, 0, 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 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; + unsigned long overflow; + unsigned long overflowed_ctrs = 0; + struct cpu_hw_events *cpu_hw_evt = dev; + u64 start_clock = sched_clock(); + + 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) { + csr_clear(CSR_SIP, BIT(riscv_pmu_irq_num)); + 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 */ + ALT_SBI_PMU_OVERFLOW(overflow); + + /* + * Overflow interrupt pending bit should only be cleared after stopping + * all the counters to avoid any race condition. + */ + csr_clear(CSR_SIP, BIT(riscv_pmu_irq_num)); + + /* 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; + + /* compute hardware counter index */ + hidx = info->csr - CSR_CYCLE; + /* check if the corresponding bit is set in sscountovf */ + if (!(overflow & (1 << hidx))) + continue; + + /* + * Keep a track of overflowed counters so that they can be started + * with updated initial value. + */ + overflowed_ctrs |= 1 << lidx; + hw_evt = &event->hw; + riscv_pmu_event_update(event); + 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); + } + } + + 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; + csr_clear(CSR_IP, BIT(riscv_pmu_irq_num)); + csr_set(CSR_IE, BIT(riscv_pmu_irq_num)); + enable_percpu_irq(riscv_pmu_irq, IRQ_TYPE_NONE); + } + + 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); + csr_clear(CSR_IE, BIT(riscv_pmu_irq_num)); + } + + /* Disable all counters access for user mode now */ + csr_write(CSR_SCOUNTEREN, 0x0); + + 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; + } + + 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) +{ + 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(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->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 = cpuhp_state_add_instance(CPUHP_AP_PERF_RISCV_STARTING, &pmu->node); + if (ret) + return ret; + + 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; + + register_sysctl("kernel", sbi_pmu_sysctl_table); + + 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; + } + + 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) |