From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailgw.kylinos.cn (mailgw.kylinos.cn [124.126.103.232]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 11368448B9A; Tue, 18 Aug 2026 09:44:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=124.126.103.232 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787046266; cv=none; b=AcXj/5pfxOyeDv08df1ojsjGIP1jDGUg5ldRUeia4eLFXJ7wmB9n9QB8zwAaYgqFbtbKycE2vWL/PQydXa1qTSYuCgOyRLssBH8DyNNnXTZxvkvb2khaX5ZsJz+WPCU8Vy25nfuaqpyEHlMMKP7dJfdscIMxEwOsamwq8aSNjgE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787046266; c=relaxed/simple; bh=+NlAcR9Xot/qrtblrGS2ZXJqxEpstEcu6m44vnGnB7Q=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=XMLj4dG4nq2gBC+VMUfo4fc9AYj0c7wBeYlyhqP315yZs8684jitsL8WNYvEK7kWZgdKx5sY649U4mfHQRQHU/ZjcaJ1DnxyYOOP7EbQ2WyQJuojr8yh694qcOSnd8ghdKYl0Qt+sWYCCDoFcT3dsEf9sP+tKKmAOjZ68BDTaZE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=kylinos.cn; spf=pass smtp.mailfrom=kylinos.cn; arc=none smtp.client-ip=124.126.103.232 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=kylinos.cn Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=kylinos.cn X-UUID: 60c2f81c9ae911f19a56ed5b684f684d-20260818 X-CID-P-RULE: Release_Ham X-CID-O-INFO: VERSION:1.3.19,REQID:10c2699f-1ac5-4ebe-9e77-cd577d86eece,IP:0,U RL:0,TC:0,Content:0,EDM:0,RT:0,SF:0,FILE:0,BULK:0,RULE:Release_Ham,ACTION: release,TS:0 X-CID-META: VersionHash:7db8b62,CLOUDID:fa69c7c4ded2daf118ea4f197c639993,BulkI D:nil,BulkQuantity:0,SF:81|82|102|865|898,TC:nil,Content:0|15|50,EDM:-3,IP :nil,URL:0,File:nil,RT:nil,Bulk:nil,QS:nil,BEC:nil,COL:0,OSI:0,OSA:0,AV:0, LES:1,SPR:NO,DKR:0,DKP:0,BRR:0,BRE:0,ARC:0 X-CID-BVR: 2,SSN|SDN X-CID-BAS: 2,SSN|SDN,0,_ X-CID-FACTOR: TF_CID_SPAM_SNR X-CID-RHF: D41D8CD98F00B204E9800998ECF8427E X-UUID: 60c2f81c9ae911f19a56ed5b684f684d-20260818 X-User: liuxixin@kylinos.cn Received: from [127.0.1.1] [(10.44.16.150)] by mailgw.kylinos.cn (envelope-from ) (Generic MTA with TLSv1.3 TLS_AES_256_GCM_SHA384 256/256) with ESMTP id 1797780881; Tue, 18 Aug 2026 17:44:16 +0800 From: Xixin Liu To: linux-riscv@lists.infradead.org Cc: atish.patra@linux.dev, anup@brainfault.org, will@kernel.org, mark.rutland@arm.com, pjw@kernel.org, palmer@dabbelt.com, aou@eecs.berkeley.edu, alex@ghiti.fr, linux-arm-kernel@lists.infradead.org, linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org, liuxixin@kylinos.cn Subject: [PATCH v2 2/2] perf: RISC-V: store available counter mask as bitmap Date: Tue, 18 Aug 2026 17:10:00 +0800 Message-ID: In-Reply-To: References: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Mailer: patches/scripts/send-local.py The available-counter mask was a single unsigned long, but iteration uses RISCV_MAX_COUNTERS, which is 64. On RV32 that reads past the object. Filling with an unsigned-long bit at index 32 and above is also wrong. Use DECLARE_BITMAP and set_bit/bitmap helpers. Walk each bitmap word into CFG_MATCH when checking events, when allocating an index, and when stopping all counters. Set the counter base to i times BITS_PER_LONG. Share the CFG_MATCH ecall through a small helper so the 32-bit argument split is not duplicated. On qemu-system-riscv32 the probe bitmap has bits above XLEN set, so the first word alone is not enough. Fixes: e9991434596f ("RISC-V: Add perf platform driver based on SBI PMU extension") Assisted-by: DeepSeek:deepseek-v3 Signed-off-by: Xixin Liu --- drivers/perf/riscv_pmu_legacy.c | 5 +- drivers/perf/riscv_pmu_sbi.c | 88 ++++++++++++++++++++++++++++------------ include/linux/perf/riscv_pmu.h | 2 3 files changed, 66 insertions(+), 29 deletions(-) diff --git a/drivers/perf/riscv_pmu_legacy.c b/drivers/perf/riscv_pmu_legacy.c --- a/drivers/perf/riscv_pmu_legacy.c +++ b/drivers/perf/riscv_pmu_legacy.c @@ -111,8 +111,9 @@ static void pmu_legacy_init(struct riscv_pmu *pmu) { pr_info("Legacy PMU implementation is available\n"); - pmu->cmask = BIT(RISCV_PMU_LEGACY_CYCLE) | - BIT(RISCV_PMU_LEGACY_INSTRET); + bitmap_zero(pmu->cmask, RISCV_MAX_COUNTERS); + set_bit(RISCV_PMU_LEGACY_CYCLE, pmu->cmask); + set_bit(RISCV_PMU_LEGACY_INSTRET, pmu->cmask); pmu->ctr_start = pmu_legacy_ctr_start; pmu->ctr_stop = NULL; pmu->event_map = pmu_legacy_event_map; diff --git a/drivers/perf/riscv_pmu_sbi.c b/drivers/perf/riscv_pmu_sbi.c --- a/drivers/perf/riscv_pmu_sbi.c +++ b/drivers/perf/riscv_pmu_sbi.c @@ -97,7 +97,7 @@ static unsigned int riscv_pmu_irq_mask; static unsigned int riscv_pmu_irq; /* Cache the available counters in a bitmask */ -static unsigned long cmask; +static DECLARE_BITMAP(cmask, RISCV_MAX_COUNTERS); struct sbi_pmu_event_data { union { @@ -298,16 +298,38 @@ static struct sbi_pmu_event_data pmu_cache_event_map[PERF_COUNT_HW_CACHE_MAX] }, }; +static struct sbiret pmu_sbi_ctr_cfg_match(unsigned long cbase, + unsigned long ctr_mask, + unsigned long cflags, + unsigned long event_idx, + u64 config) +{ +#if defined(CONFIG_32BIT) + return sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_CFG_MATCH, cbase, + ctr_mask, cflags, event_idx, config, config >> 32); +#else + return sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_CFG_MATCH, cbase, + ctr_mask, cflags, event_idx, config, 0); +#endif +} + static void pmu_sbi_check_event(struct sbi_pmu_event_data *edata) { - struct sbiret ret; + struct sbiret ret = { .error = SBI_ERR_NOT_SUPPORTED }; + int i; - 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) { + for (i = 0; i < BITS_TO_LONGS(RISCV_MAX_COUNTERS); i++) { + if (!cmask[i]) + continue; + ret = pmu_sbi_ctr_cfg_match(i * BITS_PER_LONG, cmask[i], 0, + edata->event_idx, 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); + return; + } + } + if (ret.error == SBI_ERR_NOT_SUPPORTED) { /* This event cannot be monitored by any counter */ edata->event_idx = -ENOENT; } @@ -353,10 +375,10 @@ int riscv_pmu_get_hpm_info(u32 *hw_ctr_width, u32 *num_hw_ctr) union sbi_pmu_ctr_info *info; u32 hpm_width = 0, hpm_count = 0; - if (!cmask) + if (bitmap_empty(cmask, RISCV_MAX_COUNTERS)) return -EINVAL; - for_each_set_bit(i, &cmask, RISCV_MAX_COUNTERS) { + for_each_set_bit(i, cmask, RISCV_MAX_COUNTERS) { info = &pmu_ctr_list[i]; if (!info) continue; @@ -405,8 +427,8 @@ static int pmu_sbi_ctr_get_idx(struct perf_event *event) 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; + int idx, i; + uint64_t cbase = 0, cmask = 0; unsigned long cflags = 0; cflags = pmu_sbi_get_filter_flags(event); @@ -427,14 +449,21 @@ static int pmu_sbi_ctr_get_idx(struct perf_event *event) } /* 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 (cmask) { + ret = pmu_sbi_ctr_cfg_match(cbase, cmask, cflags, hwc->event_base, + hwc->config); + } else { + ret.error = SBI_ERR_NOT_SUPPORTED; + for (i = 0; i < BITS_TO_LONGS(RISCV_MAX_COUNTERS); i++) { + if (!rvpmu->cmask[i]) + continue; + cbase = i * BITS_PER_LONG; + ret = pmu_sbi_ctr_cfg_match(cbase, rvpmu->cmask[i], cflags, + hwc->event_base, hwc->config); + if (!ret.error) + break; + } + } if (ret.error) { pr_debug("Not able to find a counter for event %lx config %llx\n", hwc->event_base, hwc->config); @@ -442,7 +471,7 @@ static int pmu_sbi_ctr_get_idx(struct perf_event *event) } idx = ret.value; - if (!test_bit(idx, &rvpmu->cmask) || !pmu_ctr_list[idx].value) + if (!test_bit(idx, rvpmu->cmask) || !pmu_ctr_list[idx].value) return -ENOENT; /* Additional sanity check for the counter id */ @@ -794,7 +823,7 @@ static int pmu_sbi_get_ctrinfo(int nctr, unsigned long *mask) /* The logical counter ids are not expected to be contiguous */ continue; - *mask |= BIT(i); + set_bit(i, mask); cinfo.value = ret.value; if (cinfo.type == SBI_PMU_CTR_TYPE_FW) @@ -811,12 +840,19 @@ static int pmu_sbi_get_ctrinfo(int nctr, unsigned long *mask) static inline void pmu_sbi_stop_all(struct riscv_pmu *pmu) { + int i; + /* * 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); + for (i = 0; i < BITS_TO_LONGS(RISCV_MAX_COUNTERS); i++) { + if (!pmu->cmask[i]) + continue; + sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_STOP, + i * BITS_PER_LONG, pmu->cmask[i], + SBI_PMU_STOP_FLAG_RESET, 0, 0, 0); + } } static inline void pmu_sbi_stop_hw_ctrs(struct riscv_pmu *pmu) @@ -1353,7 +1389,7 @@ static int pmu_sbi_device_probe(struct platform_device *pdev) } /* cache all the information about counters now */ - if (pmu_sbi_get_ctrinfo(num_counters, &cmask)) + if (pmu_sbi_get_ctrinfo(num_counters, cmask)) goto out_free; ret = pmu_sbi_setup_irqs(pmu, pdev); @@ -1365,7 +1401,7 @@ static int pmu_sbi_device_probe(struct platform_device *pdev) pmu->pmu.attr_groups = riscv_pmu_attr_groups; pmu->pmu.parent = &pdev->dev; - pmu->cmask = cmask; + bitmap_copy(pmu->cmask, cmask, RISCV_MAX_COUNTERS); pmu->ctr_start = pmu_sbi_ctr_start; pmu->ctr_stop = pmu_sbi_ctr_stop; pmu->event_map = pmu_sbi_event_map; diff --git a/include/linux/perf/riscv_pmu.h b/include/linux/perf/riscv_pmu.h --- a/include/linux/perf/riscv_pmu.h +++ b/include/linux/perf/riscv_pmu.h @@ -55,7 +55,7 @@ struct riscv_pmu { irqreturn_t (*handle_irq)(int irq_num, void *dev); - unsigned long cmask; + DECLARE_BITMAP(cmask, RISCV_MAX_COUNTERS); u64 (*ctr_read)(struct perf_event *event); int (*ctr_get_idx)(struct perf_event *event); int (*ctr_get_width)(int idx); -- 2.43.0