From patchwork Mon Jul 3 12:46:42 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexandre Ghiti X-Patchwork-Id: 13300038 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id A221BEB64DC for ; Mon, 3 Jul 2023 12:52:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=2gkixuBxUhEicXjGDEUOTfnNKMRiFNEDnLSI/1zMzN0=; b=SAQWfxIu6H91Hb mSz1SrT0f6qsJpEy+LlZX9cefozf4ItaPTayaIxsaiCrXqtYL39f8/jYk/IhV69HaNmikR0C6APn2 nxOyRvlloVt5b14+hRJPkPglV8WtFcb8IsJHOhb5Llyv7DsYCi4O6UaclbuCuteLZ5/ENFqwg4WTv tmWxklxjoB329XQmlP3qhmTyFeHFL1BZuVkakQE2FJLoWCQ6HJJKZiYFWbf3+2+MR6KLl9yYTRYRC c8oryLYv3Ee+iSEFguJG0HyeRMZUoQ8w3y3lXIh99pnuYAJsOVZBoiGOzE5NU90pXS1Di+HttqllL p4/YW73du9Y11NDuXJoA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qGJ2A-00AXdN-14; Mon, 03 Jul 2023 12:52:02 +0000 Received: from mail-wr1-x430.google.com ([2a00:1450:4864:20::430]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1qGJ26-00AXaL-2f for linux-riscv@lists.infradead.org; Mon, 03 Jul 2023 12:52:00 +0000 Received: by mail-wr1-x430.google.com with SMTP id ffacd0b85a97d-31297125334so3749583f8f.0 for ; Mon, 03 Jul 2023 05:51:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=rivosinc-com.20221208.gappssmtp.com; s=20221208; t=1688388715; x=1690980715; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=ZCeWMY4/agdKjOcZQsz9uVIpEMibHxn6xO98sYlIUOg=; b=Tznjz1yQSiexpcUQrGx/dfamAweEDsi+ZhChFoC+CScdfP4dQkjMEt5yYAcSCnjTj5 prbJxeDQoLA9Vps91R8TcYta5h9vcxsZqKQJGQOS4Ad0Ln+5xvt+hccO0IKxm50qu0dp 057O0xpyWz0St5XPT3Bpfvck/cw4/QeN1u6efsal6J1JxgZcLzuZWpEXUMQTbcCOV2wP FjNwU7DVfJOEWAUDwx9fSjN8ypCLBSoYAah6iDhbfXR36fI6L/dCEm4gh9i3dMkmE7J+ 0EBDiDTYGHaVsztDfRyiRaXieRo1fJVxfF7Y2Wp1mTT3PlSLTnVxBLL9El3PqMV4w3ij 0I9Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1688388715; x=1690980715; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=ZCeWMY4/agdKjOcZQsz9uVIpEMibHxn6xO98sYlIUOg=; b=fPekZyqBoE4YCCW5qmORyx43oMK177RGBLuSFaKEjyQ25C407CEMFPEdOVpfcTV6C8 qStal1e/LBP+BpmOyihodrIXfPkLh0qNnPR8RaoOeK4N9RwTCfpsiYYdOAf8oOhdgbKS GgJM8A+00BOk4Hcdu0XNk0vYiCKGmdLvA0vi+iMkUwWq+QO92DRptsM4duCB5r+C7HRP 4Pop1CvY310cncSeHqG2Iyvm5bfcnlfeqzrk4Zpgav9xvYGe/TlJgyPh6iK0ZutBIN0r RfV56jc0+/vcdlsI0tkC1YrwwAjHfehgCxyJ3V32Ttfgv9S15fCXeFDzI/OjZuMdH8i/ LECw== X-Gm-Message-State: AC+VfDxCT/c/JC1VaP5s8leKX+oZL/kUbDMJX+XQK144h4/SIA9PWF/p +VroKbVYRQVhj8HBBRKhW69c0A== X-Google-Smtp-Source: ACHHUZ6L/2B+7rqmbA0qSqdtpgKONqNqBBfw4eWPQLPnIrM4e13gOeEYnGpRaZblqJRK0Eh9+AaAaw== X-Received: by 2002:a5d:4586:0:b0:314:3f1:cebf with SMTP id p6-20020a5d4586000000b0031403f1cebfmr14543697wrq.28.1688388715260; Mon, 03 Jul 2023 05:51:55 -0700 (PDT) Received: from alex-rivos.home (amontpellier-656-1-456-62.w92-145.abo.wanadoo.fr. [92.145.124.62]) by smtp.gmail.com with ESMTPSA id w10-20020adfcd0a000000b003141f96ed36sm9280510wrm.0.2023.07.03.05.51.54 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 03 Jul 2023 05:51:54 -0700 (PDT) From: Alexandre Ghiti To: Jonathan Corbet , Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Mark Rutland , Alexander Shishkin , Jiri Olsa , Namhyung Kim , Ian Rogers , Paul Walmsley , Palmer Dabbelt , Albert Ou , Atish Patra , Anup Patel , Will Deacon , Rob Herring , Andrew Jones , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, linux-riscv@lists.infradead.org, linux-arm-kernel@lists.infradead.org Cc: Alexandre Ghiti Subject: [PATCH v4 05/10] riscv: Prepare for user-space perf event mmap support Date: Mon, 3 Jul 2023 14:46:42 +0200 Message-Id: <20230703124647.215952-6-alexghiti@rivosinc.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230703124647.215952-1-alexghiti@rivosinc.com> References: <20230703124647.215952-1-alexghiti@rivosinc.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230703_055158_872053_53BA8E8E X-CRM114-Status: GOOD ( 20.62 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org Provide all the necessary bits in the generic riscv pmu driver to be able to mmap perf events in userspace: the heavy lifting lies in the driver backend, namely the legacy and sbi implementations. Note that arch_perf_update_userpage is almost a copy of arm64 code. Signed-off-by: Alexandre Ghiti Reviewed-by: Andrew Jones Reviewed-by: Atish Patra --- drivers/perf/riscv_pmu.c | 105 +++++++++++++++++++++++++++++++++ include/linux/perf/riscv_pmu.h | 4 ++ 2 files changed, 109 insertions(+) diff --git a/drivers/perf/riscv_pmu.c b/drivers/perf/riscv_pmu.c index ebca5eab9c9b..432ad2e80ce3 100644 --- a/drivers/perf/riscv_pmu.c +++ b/drivers/perf/riscv_pmu.c @@ -14,9 +14,73 @@ #include #include #include +#include #include +static bool riscv_perf_user_access(struct perf_event *event) +{ + return ((event->attr.type == PERF_TYPE_HARDWARE) || + (event->attr.type == PERF_TYPE_HW_CACHE) || + (event->attr.type == PERF_TYPE_RAW)) && + !!(event->hw.flags & PERF_EVENT_FLAG_USER_READ_CNT); +} + +void arch_perf_update_userpage(struct perf_event *event, + struct perf_event_mmap_page *userpg, u64 now) +{ + struct clock_read_data *rd; + unsigned int seq; + u64 ns; + + userpg->cap_user_time = 0; + userpg->cap_user_time_zero = 0; + userpg->cap_user_time_short = 0; + userpg->cap_user_rdpmc = riscv_perf_user_access(event); + + userpg->pmc_width = 64; + + do { + rd = sched_clock_read_begin(&seq); + + userpg->time_mult = rd->mult; + userpg->time_shift = rd->shift; + userpg->time_zero = rd->epoch_ns; + userpg->time_cycles = rd->epoch_cyc; + userpg->time_mask = rd->sched_clock_mask; + + /* + * Subtract the cycle base, such that software that + * doesn't know about cap_user_time_short still 'works' + * assuming no wraps. + */ + ns = mul_u64_u32_shr(rd->epoch_cyc, rd->mult, rd->shift); + userpg->time_zero -= ns; + + } while (sched_clock_read_retry(seq)); + + userpg->time_offset = userpg->time_zero - now; + + /* + * time_shift is not expected to be greater than 31 due to + * the original published conversion algorithm shifting a + * 32-bit value (now specifies a 64-bit value) - refer + * perf_event_mmap_page documentation in perf_event.h. + */ + if (userpg->time_shift == 32) { + userpg->time_shift = 31; + userpg->time_mult >>= 1; + } + + /* + * Internal timekeeping for enabled/running/stopped times + * is always computed with the sched_clock. + */ + userpg->cap_user_time = 1; + userpg->cap_user_time_zero = 1; + userpg->cap_user_time_short = 1; +} + static unsigned long csr_read_num(int csr_num) { #define switchcase_csr_read(__csr_num, __val) {\ @@ -171,6 +235,8 @@ int riscv_pmu_event_set_period(struct perf_event *event) local64_set(&hwc->prev_count, (u64)-left); + perf_event_update_userpage(event); + return overflow; } @@ -267,6 +333,9 @@ static int riscv_pmu_event_init(struct perf_event *event) hwc->idx = -1; hwc->event_base = mapped_event; + if (rvpmu->event_init) + rvpmu->event_init(event); + if (!is_sampling_event(event)) { /* * For non-sampling runs, limit the sample_period to half @@ -283,6 +352,39 @@ static int riscv_pmu_event_init(struct perf_event *event) return 0; } +static int riscv_pmu_event_idx(struct perf_event *event) +{ + struct riscv_pmu *rvpmu = to_riscv_pmu(event->pmu); + + if (!(event->hw.flags & PERF_EVENT_FLAG_USER_READ_CNT)) + return 0; + + if (rvpmu->csr_index) + return rvpmu->csr_index(event) + 1; + + return 0; +} + +static void riscv_pmu_event_mapped(struct perf_event *event, struct mm_struct *mm) +{ + struct riscv_pmu *rvpmu = to_riscv_pmu(event->pmu); + + if (rvpmu->event_mapped) { + rvpmu->event_mapped(event, mm); + perf_event_update_userpage(event); + } +} + +static void riscv_pmu_event_unmapped(struct perf_event *event, struct mm_struct *mm) +{ + struct riscv_pmu *rvpmu = to_riscv_pmu(event->pmu); + + if (rvpmu->event_unmapped) { + rvpmu->event_unmapped(event, mm); + perf_event_update_userpage(event); + } +} + struct riscv_pmu *riscv_pmu_alloc(void) { struct riscv_pmu *pmu; @@ -307,6 +409,9 @@ struct riscv_pmu *riscv_pmu_alloc(void) } pmu->pmu = (struct pmu) { .event_init = riscv_pmu_event_init, + .event_mapped = riscv_pmu_event_mapped, + .event_unmapped = riscv_pmu_event_unmapped, + .event_idx = riscv_pmu_event_idx, .add = riscv_pmu_add, .del = riscv_pmu_del, .start = riscv_pmu_start, diff --git a/include/linux/perf/riscv_pmu.h b/include/linux/perf/riscv_pmu.h index 5deeea0be7cb..43282e22ebe1 100644 --- a/include/linux/perf/riscv_pmu.h +++ b/include/linux/perf/riscv_pmu.h @@ -55,6 +55,10 @@ struct riscv_pmu { void (*ctr_start)(struct perf_event *event, u64 init_val); void (*ctr_stop)(struct perf_event *event, unsigned long flag); int (*event_map)(struct perf_event *event, u64 *config); + void (*event_init)(struct perf_event *event); + void (*event_mapped)(struct perf_event *event, struct mm_struct *mm); + void (*event_unmapped)(struct perf_event *event, struct mm_struct *mm); + uint8_t (*csr_index)(struct perf_event *event); struct cpu_hw_events __percpu *hw_events; struct hlist_node node;