From 7dda24bacc05ae4e43b75aab347e4df07e002502 Mon Sep 17 00:00:00 2001 From: Atish Patra Date: Sat, 20 Apr 2024 08:17:19 -0700 Subject: [PATCH] drivers/perf: riscv: Read upper bits of a firmware counter SBI v2.0 introduced a explicit function to read the upper 32 bits for any firmware counter width that is longer than 32bits. This is only applicable for RV32 where firmware counter can be 64 bit. Reviewed-by: Andrew Jones Acked-by: Palmer Dabbelt Reviewed-by: Conor Dooley Reviewed-by: Anup Patel Signed-off-by: Atish Patra Link: https://lore.kernel.org/r/20240420151741.962500-4-atishp@rivosinc.com Signed-off-by: Anup Patel --- drivers/perf/riscv_pmu_sbi.c | 25 ++++++++++++++++++++----- 1 file changed, 20 insertions(+), 5 deletions(-) diff --git a/drivers/perf/riscv_pmu_sbi.c b/drivers/perf/riscv_pmu_sbi.c index 3e44d2fb8bf81..1823ffb25d358 100644 --- a/drivers/perf/riscv_pmu_sbi.c +++ b/drivers/perf/riscv_pmu_sbi.c @@ -57,6 +57,8 @@ asm volatile(ALTERNATIVE( \ PMU_FORMAT_ATTR(event, "config:0-47"); PMU_FORMAT_ATTR(firmware, "config:63"); +static bool sbi_v2_available; + static struct attribute *riscv_arch_formats_attr[] = { &format_attr_event.attr, &format_attr_firmware.attr, @@ -511,19 +513,29 @@ 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; + union sbi_pmu_ctr_info info = pmu_ctr_list[idx]; 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; + 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 { - 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; + val |= ((u64)riscv_pmu_ctr_read_csr(info.csr + 0x80)) << 32; } return val; @@ -1135,6 +1147,9 @@ static int __init pmu_sbi_devinit(void) 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); -- 2.30.2