From patchwork Wed Jan 3 11:55:52 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "D, Lakshmi Sowjanya" X-Patchwork-Id: 13509949 Received: from mgamail.intel.com (mgamail.intel.com [192.55.52.88]) (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 053BF18EB8; Wed, 3 Jan 2024 11:56:16 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="Wcb9MHcR" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1704282977; x=1735818977; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=ZPkSKpjHiCLvC9ZF7FXCFqefztas4HRUN72CS6lqsI8=; b=Wcb9MHcRtS2bnwncLyxjYjyjwn0vl3qcvdz6TdDrW2HoKnn8Cray5Kkx b2WFB+0Pk4Mawtvr7KYAz/EAluM43b6GZuKRleUTmYzYXEIBCzPttmr+3 8AqVqZXhdimCu1xX5O4WYCx8YHJG/93csSxsAklfAolqwyRg0RKXmvmmE A5Cvt1g8KaKSoM9vwGtYr3W9n9bAc5KgjWU3TLBkWgzyVm4u/igZeJYR5 AGFr+UVu4ISdXWWMLrWqBNAVYtwpMZi4NvdBKOJU/MzJjnrSgbkk2+lLb nEqEGSsPT1XUHwBcPbdZym55trfewsoMtYM/2VEp4RtfW7jejJC+HefiU Q==; X-IronPort-AV: E=McAfee;i="6600,9927,10941"; a="428169417" X-IronPort-AV: E=Sophos;i="6.04,327,1695711600"; d="scan'208";a="428169417" Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 03 Jan 2024 03:56:16 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10941"; a="1111348031" X-IronPort-AV: E=Sophos;i="6.04,327,1695711600"; d="scan'208";a="1111348031" Received: from inlubt0316.iind.intel.com ([10.191.20.213]) by fmsmga005.fm.intel.com with ESMTP; 03 Jan 2024 03:56:09 -0800 From: lakshmi.sowjanya.d@intel.com To: tglx@linutronix.de, jstultz@google.com, giometti@enneenne.com, corbet@lwn.net, linux-kernel@vger.kernel.org Cc: x86@kernel.org, netdev@vger.kernel.org, linux-doc@vger.kernel.org, intel-wired-lan@lists.osuosl.org, andriy.shevchenko@linux.intel.com, eddie.dong@intel.com, christopher.s.hall@intel.com, jesse.brandeburg@intel.com, davem@davemloft.net, alexandre.torgue@foss.st.com, joabreu@synopsys.com, mcoquelin.stm32@gmail.com, perex@perex.cz, linux-sound@vger.kernel.org, anthony.l.nguyen@intel.com, pandith.n@intel.com, mallikarjunappa.sangannavar@intel.com, thejesh.reddy.t.r@intel.com, lakshmi.sowjanya.d@intel.com Subject: [RFC PATCH v3 01/11] x86/tsc: Add base clock properties in clocksource structure Date: Wed, 3 Jan 2024 17:25:52 +0530 Message-Id: <20240103115602.19044-2-lakshmi.sowjanya.d@intel.com> X-Mailer: git-send-email 2.35.3 In-Reply-To: <20240103115602.19044-1-lakshmi.sowjanya.d@intel.com> References: <20240103115602.19044-1-lakshmi.sowjanya.d@intel.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Patchwork-State: RFC From: Lakshmi Sowjanya D Add hardware abstraction, struct clocksource_base in clocksource. Add clocksource ID for x86 ART(Always Running Timer). Co-developed-by: Thomas Gleixner Signed-off-by: Thomas Gleixner Co-developed-by: Christopher S. Hall Signed-off-by: Christopher S. Hall Signed-off-by: Lakshmi Sowjanya D --- arch/x86/kernel/tsc.c | 43 ++++++++++++++++++--------------- include/linux/clocksource.h | 27 +++++++++++++++++++++ include/linux/clocksource_ids.h | 1 + 3 files changed, 52 insertions(+), 19 deletions(-) diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c index 868f09966b0f..035ae5bec2e8 100644 --- a/arch/x86/kernel/tsc.c +++ b/arch/x86/kernel/tsc.c @@ -51,9 +51,9 @@ int tsc_clocksource_reliable; static int __read_mostly tsc_force_recalibrate; -static u32 art_to_tsc_numerator; -static u32 art_to_tsc_denominator; -static u64 art_to_tsc_offset; +static struct clocksource_base art_base_clk = { + .id = CSID_X86_ART, +}; static bool have_art; struct cyc2ns { @@ -1075,7 +1075,7 @@ core_initcall(cpufreq_register_tsc_scaling); */ static void __init detect_art(void) { - unsigned int unused[2]; + unsigned int unused; if (boot_cpu_data.cpuid_level < ART_CPUID_LEAF) return; @@ -1090,13 +1090,14 @@ static void __init detect_art(void) tsc_async_resets) return; - cpuid(ART_CPUID_LEAF, &art_to_tsc_denominator, - &art_to_tsc_numerator, unused, unused+1); + cpuid(ART_CPUID_LEAF, &art_base_clk.denominator, + &art_base_clk.numerator, &art_base_clk.freq_khz, &unused); - if (art_to_tsc_denominator < ART_MIN_DENOMINATOR) + art_base_clk.freq_khz /= KHZ; + if (art_base_clk.denominator < ART_MIN_DENOMINATOR) return; - rdmsrl(MSR_IA32_TSC_ADJUST, art_to_tsc_offset); + rdmsrl(MSR_IA32_TSC_ADJUST, art_base_clk.offset); /* Make this sticky over multiple CPU init calls */ setup_force_cpu_cap(X86_FEATURE_ART); @@ -1304,13 +1305,13 @@ struct system_counterval_t convert_art_to_tsc(u64 art) { u64 tmp, res, rem; - rem = do_div(art, art_to_tsc_denominator); + rem = do_div(art, art_base_clk.denominator); - res = art * art_to_tsc_numerator; - tmp = rem * art_to_tsc_numerator; + res = art * art_base_clk.numerator; + tmp = rem * art_base_clk.numerator; - do_div(tmp, art_to_tsc_denominator); - res += tmp + art_to_tsc_offset; + do_div(tmp, art_base_clk.denominator); + res += tmp + art_base_clk.offset; return (struct system_counterval_t) { .cs_id = have_art ? CSID_X86_TSC : CSID_GENERIC, @@ -1351,7 +1352,6 @@ struct system_counterval_t convert_art_ns_to_tsc(u64 art_ns) do_div(tmp, USEC_PER_SEC); res += tmp; - return (struct system_counterval_t) { .cs_id = have_art ? CSID_X86_TSC : CSID_GENERIC, .cycles = res @@ -1359,7 +1359,6 @@ struct system_counterval_t convert_art_ns_to_tsc(u64 art_ns) } EXPORT_SYMBOL(convert_art_ns_to_tsc); - static void tsc_refine_calibration_work(struct work_struct *work); static DECLARE_DELAYED_WORK(tsc_irqwork, tsc_refine_calibration_work); /** @@ -1461,8 +1460,10 @@ static void tsc_refine_calibration_work(struct work_struct *work) if (tsc_unstable) goto unreg; - if (boot_cpu_has(X86_FEATURE_ART)) + if (boot_cpu_has(X86_FEATURE_ART)) { have_art = true; + clocksource_tsc.base = &art_base_clk; + } clocksource_register_khz(&clocksource_tsc, tsc_khz); unreg: clocksource_unregister(&clocksource_tsc_early); @@ -1487,8 +1488,10 @@ static int __init init_tsc_clocksource(void) * the refined calibration and directly register it as a clocksource. */ if (boot_cpu_has(X86_FEATURE_TSC_KNOWN_FREQ)) { - if (boot_cpu_has(X86_FEATURE_ART)) + if (boot_cpu_has(X86_FEATURE_ART)) { have_art = true; + clocksource_tsc.base = &art_base_clk; + } clocksource_register_khz(&clocksource_tsc, tsc_khz); clocksource_unregister(&clocksource_tsc_early); @@ -1512,10 +1515,12 @@ static bool __init determine_cpu_tsc_frequencies(bool early) if (early) { cpu_khz = x86_platform.calibrate_cpu(); - if (tsc_early_khz) + if (tsc_early_khz) { tsc_khz = tsc_early_khz; - else + } else { tsc_khz = x86_platform.calibrate_tsc(); + clocksource_tsc.freq_khz = tsc_khz; + } } else { /* We should not be here with non-native cpu calibration */ WARN_ON(x86_platform.calibrate_cpu != native_calibrate_cpu); diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h index 1d42d4b17327..0a1110a0e660 100644 --- a/include/linux/clocksource.h +++ b/include/linux/clocksource.h @@ -21,6 +21,7 @@ #include #include +struct clocksource_base; struct clocksource; struct module; @@ -48,6 +49,7 @@ struct module; * @archdata: Optional arch-specific data * @max_cycles: Maximum safe cycle value which won't overflow on * multiplication + * @freq_khz: Clocksource frequency in khz. * @name: Pointer to clocksource name * @list: List head for registration (internal) * @rating: Rating value for selection (higher is better) @@ -70,6 +72,8 @@ struct module; * validate the clocksource from which the snapshot was * taken. * @flags: Flags describing special properties + * @base: Hardware abstraction for clock on which a clocksource + * is based * @enable: Optional function to enable the clocksource * @disable: Optional function to disable the clocksource * @suspend: Optional suspend function for the clocksource @@ -105,12 +109,14 @@ struct clocksource { struct arch_clocksource_data archdata; #endif u64 max_cycles; + u32 freq_khz; const char *name; struct list_head list; int rating; enum clocksource_ids id; enum vdso_clock_mode vdso_clock_mode; unsigned long flags; + struct clocksource_base *base; int (*enable)(struct clocksource *cs); void (*disable)(struct clocksource *cs); @@ -294,4 +300,25 @@ static inline void timer_probe(void) {} extern ulong max_cswd_read_retries; void clocksource_verify_percpu(struct clocksource *cs); +/** + * struct clocksource_base - hardware abstraction for clock on which a clocksource + * is based + * @id: Defaults to CSID_GENERIC. The id value is used for conversion + * functions which require that the current clocksource is based + * on a clocksource_base with a particular ID in certain snapshot + * functions to allow callers to validate the clocksource from + * which the snapshot was taken. + * @freq_khz: Nominal frequency of the base clock in kHz + * @offset: Offset between the base clock and the clocksource + * @numerator: Numerator of the clock ratio between base clock and the clocksource + * @denominator: Denominator of the clock ratio between base clock and the clocksource + */ +struct clocksource_base { + enum clocksource_ids id; + u32 freq_khz; + u64 offset; + u32 numerator; + u32 denominator; +}; + #endif /* _LINUX_CLOCKSOURCE_H */ diff --git a/include/linux/clocksource_ids.h b/include/linux/clocksource_ids.h index a4fa3436940c..2bb4d8c2f1b0 100644 --- a/include/linux/clocksource_ids.h +++ b/include/linux/clocksource_ids.h @@ -9,6 +9,7 @@ enum clocksource_ids { CSID_X86_TSC_EARLY, CSID_X86_TSC, CSID_X86_KVM_CLK, + CSID_X86_ART, CSID_MAX, };