From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.alien8.de (mail.alien8.de [65.109.113.108]) (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 0DF5F34A794; Fri, 6 Mar 2026 10:46:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=65.109.113.108 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772793983; cv=none; b=CDV3S2J17KDN5Z71gkocyURYo7vVy1YhQtUqv3RqoNr4+lnP35AtTVGLzqG85xNTCnxq0CNNT6W3XyX1Y55yHDu74+J9JaIucoId5gP+bGWXXwzf+ALWAmC2ao7xv5b2sgAscVO8eoH5x3rMwfCh1I1AzKIS8rLl4NVV8N93yc0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772793983; c=relaxed/simple; bh=DytPJVWYAm4Wg2/XbzEmYMNnO3h8berMMtkHIDxewNw=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=tVz0d+1pBcV0cOQzTPgVHMGRzNJ7YUyNl8W2GrCjoZQIELCft2Cur7K4vzDmkBoRzNh0Rx+3vJTHidMgKUwnbhR660b+yalusPrE0AE44hAYkjNrhb8EGvKHZq2LKfYBNsh1b6yRVL0fhCDDASl0YrDmt71o8/zM3jiiYf29IRc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=alien8.de; spf=pass smtp.mailfrom=alien8.de; dkim=pass (4096-bit key) header.d=alien8.de header.i=@alien8.de header.b=A7yjEwi+; arc=none smtp.client-ip=65.109.113.108 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=alien8.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=alien8.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (4096-bit key) header.d=alien8.de header.i=@alien8.de header.b="A7yjEwi+" Received: from localhost (localhost.localdomain [127.0.0.1]) by mail.alien8.de (SuperMail on ZX Spectrum 128k) with ESMTP id E0E3140E0163; Fri, 6 Mar 2026 10:46:11 +0000 (UTC) X-Virus-Scanned: Debian amavisd-new at mail.alien8.de Authentication-Results: mail.alien8.de (amavisd-new); dkim=pass (4096-bit key) header.d=alien8.de Received: from mail.alien8.de ([127.0.0.1]) by localhost (mail.alien8.de [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id 4e4XMhoLWWGS; Fri, 6 Mar 2026 10:46:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=alien8; t=1772793967; bh=fJtwjIlBAjA3TEbIna0Icg3uhOYjYdlUmgEG9ABfNCg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=A7yjEwi+/R7cEWbrAq8fgpwufGy5PswIB068+ZAmiIWH+q4IEzF+GdGNT07pkoGAo vVOV+1xOMSPiaeUFW1fekxRz4QngvsPr2HQKBhvdYbBv+ItQbSWRr3SPGJ2qKOu3J6 1OVmigcJ1puHeNJb8Bemo2Bayath7IVWTYZBf4KqdIwyAaZ4LUOTpp908GELFn6eA0 Q4W2ozGOgvjMM75IPBsq/cIzqxHmZyy3v8YcpT1EZQQDbTgnn2TjOyXVwD4UtfDA7p yft3WtVVf2wJcyv0eTmlX4pVL5K3COPjwjuZPdSXxdiCLqRRWDOk7ARgCIyztzNQMP ONnP2zl04ECtczW00xiBiXVrgAK7e+o6R5DlpoyK0tT+oJIIaO67jAerRAY4X9cGgg n4RSHsRlLPrhwuF1jX0LPCQJAnccqKbKlWoq1XGqf8ivIj5xGn7250Ah227kdIZt6a oeIIE6x3C6GfmtNAt14A/PN7sWsQJO/Oa2RvFhgKgi0Y+aKC6miw8MbA51kJJLxiPe +vbnzlX8ZsnESFG0ZVorFCSD2vwNxnHF7y0Dg+tByo53RvoKGivQA2cRUaMZREMRFn B+Wube5jqSD9XA4nuAOtokDiVn46hml0Lc9rzO+2uE6haXTg2rh4egVEOt0rOiaKDb li7xJC+RL2fGj/2bZ3GlWBj8= Received: from zn.tnic (pd9530d5e.dip0.t-ipconnect.de [217.83.13.94]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature ECDSA (P-256) server-digest SHA256) (No client certificate requested) by mail.alien8.de (SuperMail on ZX Spectrum 128k) with UTF8SMTPSA id 41CF240E0031; Fri, 6 Mar 2026 10:45:55 +0000 (UTC) Date: Fri, 6 Mar 2026 11:45:48 +0100 From: Borislav Petkov To: "Gautham R. Shenoy" Cc: Mario Limonciello , "Rafael J . Wysocki" , Viresh Kumar , K Prateek Nayak , linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, "H. Peter Anvin" , Dave Hansen , Thomas Gleixner , Ingo Molnar , x86@kernel.org Subject: Re: [PATCH 4/9] x86/cpufeatures: Add AMD CPPC Performance Priority feature. Message-ID: <20260306104548.GCaaqwXNcglOEfp5D2@fat_crate.local> References: <20260306095753.17155-1-gautham.shenoy@amd.com> <20260306095753.17155-5-gautham.shenoy@amd.com> 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-Disposition: inline In-Reply-To: <20260306095753.17155-5-gautham.shenoy@amd.com> On Fri, Mar 06, 2026 at 03:27:48PM +0530, Gautham R. Shenoy wrote: > Some future AMD processors have feature named "CPPC Performance > Priority" which lets userspace specify different floor performance > levels for different CPUs. The platform firmware takes these different > floor performance levels into consideration while throttling the CPUs > under power/thermal constraints. The presence of this feature is > indicated by bit 16 of the EDX register for CPUID leaf > 0x80000007. More details can be found in AMD Publication titled "AMD64 > Collaborative Processor Performance Control (CPPC) Performance > Priority" Revision 1.10. > > Define a new feature bit named X86_FEATURE_CPPC_PERF_PRIO to map to > CPUID 0x80000007.EDX[16]. > > Signed-off-by: Gautham R. Shenoy > --- > Link to AMD publication describing this feature: https://docs.amd.com/v/u/en-US/69206_1.10_AMD64_CPPC_PUB > > arch/x86/include/asm/cpufeatures.h | 2 +- > arch/x86/kernel/cpu/scattered.c | 1 + > tools/arch/x86/include/asm/cpufeatures.h | 2 +- > 3 files changed, 3 insertions(+), 2 deletions(-) Reviewed-by: Borislav Petkov (AMD) -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette