From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.18]) (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 8FF4D1C75EB for ; Wed, 20 Nov 2024 19:53:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1732132415; cv=none; b=Xb7zMqjWi5fKtnsEMV5H7KCYF9vvQczljzrcZ/ezGLicyOm6kjf3aBeCrETD2Fv207HhYOie1KzAvjd9fZy8ay8rTZPxFhTNNA3BhOXxHqsFlwJtT11Ej6hqsEcY3rmmtKwb0za33cZVzlpPr+9KzQn5k8gOWEhFXQ301lJ6T50= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1732132415; c=relaxed/simple; bh=XGEydlqDd6ucRMq17/SAt12CAeMPRM0NGmY+dJiGY24=; h=Subject:To:Cc:From:Date:References:In-Reply-To:Message-Id; b=cJqUKYuUh9SQVsSJsg3VBO3VbbK5PdsupwI/5Ggs1UjOVbty5oMvht9/6xHZvpMuGEq7cJkCql1PBQwJGoHPGmJBpnR7joB/VoUCbuVBIVLc75v8k45hwOKcrBDczXgAbE/FHjJWQ8Z+n+xb4su4qeVI+iuIoehgixqL7zqy0CM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=none smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=YbT3ADRA; arc=none smtp.client-ip=192.198.163.18 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="YbT3ADRA" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1732132413; x=1763668413; h=subject:to:cc:from:date:references:in-reply-to: message-id; bh=XGEydlqDd6ucRMq17/SAt12CAeMPRM0NGmY+dJiGY24=; b=YbT3ADRAgTxPj8Ibrf2vkRJIrV6acMOcQF67r3FgDdo0B3tJoJbJTY3x qKNprZ8DLemnnYz6/V8euT0FkIM5Bc4pSWl07mrdgnKFiP/a8gu/+5a1b ixzG47lvJsGx6LVqUVoCYm6TEmXjQQXM4OwLIVNNomp/pyzWP7NMehgUx VnV5cInRiJxNB0pnZh8aKz88JYIsTQJWEmu2XNR288Ke3hunYiyPSISEb X5jRDGJ0sBL0LJM1tR5X7EONHpzdq2SaN/IhNVb5/DVisqyd+Qme1DDj6 kc/xozmlTqU0CFMDFc32RLI6gwZopdhN/ZWmo5n5I/DuhxMExOvZHinyw w==; X-CSE-ConnectionGUID: 1T9AHZchQPeLVp8+sK2qeg== X-CSE-MsgGUID: 1wTUHFtsTLK4Jxwk9pWt4Q== X-IronPort-AV: E=McAfee;i="6700,10204,11262"; a="31580950" X-IronPort-AV: E=Sophos;i="6.12,170,1728975600"; d="scan'208";a="31580950" Received: from orviesa002.jf.intel.com ([10.64.159.142]) by fmvoesa112.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Nov 2024 11:53:33 -0800 X-CSE-ConnectionGUID: yo+fgcG1RpyGIIP7BMm2FA== X-CSE-MsgGUID: mK1a3HZWQ1ykmjbQRy/cKQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.12,170,1728975600"; d="scan'208";a="120884162" Received: from davehans-spike.ostc.intel.com (HELO localhost.localdomain) ([10.165.164.11]) by orviesa002.jf.intel.com with ESMTP; 20 Nov 2024 11:53:33 -0800 Subject: [PATCH 04/11] x86/acpi: Check MWAIT feature instead of CPUID level To: linux-kernel@vger.kernel.org Cc: x86@kernel.org,tglx@linutronix.de,bp@alien8.de,rafael@kernel.org,lenb@kernel.org,dave.jiang@intel.com,irenic.rajneesh@gmail.com,david.e.box@intel.com,Dave Hansen From: Dave Hansen Date: Wed, 20 Nov 2024 11:53:32 -0800 References: <20241120195327.26E06A69@davehans-spike.ostc.intel.com> In-Reply-To: <20241120195327.26E06A69@davehans-spike.ostc.intel.com> Message-Id: <20241120195332.929A7C44@davehans-spike.ostc.intel.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: From: Dave Hansen I think this code is possibly buggy. The CPU could have a high c->cpuid_level and not support MWAIT at all. It is much more clear to just check for MWAIT support directly. Also, because of the CPU level dependency code, any CPU that has X86_FEATURE_MWAIT also has a high-enough CPUID level. Check X86_FEATURE_MWAIT instead of the CPUID level. Signed-off-by: Dave Hansen --- b/arch/x86/kernel/acpi/cstate.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff -puN arch/x86/kernel/acpi/cstate.c~mwait-leaf-checks-3 arch/x86/kernel/acpi/cstate.c --- a/arch/x86/kernel/acpi/cstate.c~mwait-leaf-checks-3 2024-11-20 11:44:17.225650902 -0800 +++ b/arch/x86/kernel/acpi/cstate.c 2024-11-20 11:44:17.225650902 -0800 @@ -173,7 +173,7 @@ int acpi_processor_ffh_cstate_probe(unsi struct cpuinfo_x86 *c = &cpu_data(cpu); long retval; - if (!cpu_cstate_entry || c->cpuid_level < CPUID_MWAIT_LEAF) + if (!cpu_cstate_entry || cpu_has(c, X86_FEATURE_MWAIT)) return -1; if (reg->bit_offset != NATIVE_CSTATE_BEYOND_HALT) _