From mboxrd@z Thu Jan 1 00:00:00 1970 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3348BC71153 for ; Mon, 28 Aug 2023 10:05:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230319AbjH1KF0 (ORCPT ); Mon, 28 Aug 2023 06:05:26 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45508 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230314AbjH1KFI (ORCPT ); Mon, 28 Aug 2023 06:05:08 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 44C58C6 for ; Mon, 28 Aug 2023 03:05:06 -0700 (PDT) From: Thomas Gleixner DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1693217104; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=llI1bC4UzeF1tVpvR70IMRjfXqcAoAEBqzcLWKtWhGI=; b=iCwoszyg4aUkMhKh03Et0dqmSC8BLO6k7Yg1lqNFGeEIIprCrs1F3ANsGfN8oEaCep4kjd /bEGnTCgCMT7VFfmyireMxzZZ3T1kgL2VZRvEso+F1+YFEMc8E0Gs5ilMZ4LYJVydLSx0R JpJLDGGPai11L6LYmWGjIQzm3xPQ9lovEy/W43ibhDW7LZYWQ80xpDZdrR/jkcOlkNn613 tUz0PtgD92TrP7JjrkNSih9vpBrKSs/LBx7IwXohdkSmqpcWW3YPdo2kYsWv+oD1gqCuJZ quiLTxP/CTI9b02rQS+nzHC46SBtdJdLOQZ1YiRdhmYCfvmH8PwSunSmS7WS3A== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1693217104; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=llI1bC4UzeF1tVpvR70IMRjfXqcAoAEBqzcLWKtWhGI=; b=nJzkC/3ohbsu3iEeb8BjQ42XMWxfH2kuvG31ItxyKrzZMmCKTEP2a1fN37zSXu7iH1FG02 ATwKHIRwXRphsRBA== To: K Prateek Nayak , LKML Cc: x86@kernel.org, Tom Lendacky , Andrew Cooper , Arjan van de Ven , Huang Rui , Juergen Gross , Dimitri Sivanich , Michael Kelley , Wei Liu , Pu Wen , Qiuxu Zhuo , Sohil Mehta , Gautham Shenoy Subject: Re: [patch V4 24/41] x86/cpu: Provide cpu_init/parse_topology() In-Reply-To: <934072fe-eca2-44df-94e7-9fed1dc8b502@amd.com> References: <20230814085006.593997112@linutronix.de> <20230814085113.471353147@linutronix.de> <934072fe-eca2-44df-94e7-9fed1dc8b502@amd.com> Date: Mon, 28 Aug 2023 12:05:03 +0200 Message-ID: <87r0nn8ots.ffs@tglx> MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Prateek! On Mon, Aug 28 2023 at 11:37, K. Prateek Nayak wrote: > On 8/14/2023 2:24 PM, Thomas Gleixner wrote: > > Since these enums come from the description of level type of CPUID leaf > 0x1f, can we have a short description clarifying what each signify. This > will also help clarify the mappings for AMD's extended CPUID leaf > 0x80000026 (specifically for CCX and CCD level types). I had following > in my mind: Makes sense. > TOPO_MODULE_DOMAIN, > + /* > + * If exists, represents a group of tiles within > + * an instance of the next domain > + * > + * On Intel: This level contains a group of Tile > + * type as described by CPUID leaf 0x1f > + * > + * On AMD: This is the group of "Complex" type > + * instances as described by CPUID leaf > + * 0x8000_0026 > + */ > TOPO_TILE_DOMAIN, > + /* > + * If exists, represents a group of dies within an > + * instance of the next domain > + * > + * On Intel: This level contains group of Die > + * type as described by CPUID leaf 0x1f > + * > + * On AMD: This is the group of "CCD (Die)" > + * type instances as described by CPUID leaf > + * 0x8000_0026 > + */ > TOPO_DIE_DOMAIN, > + /* > + * If exists, represents a group of packages > + * within the root domain > + */ > TOPO_PKG_DOMAIN, > + /* Topmost domain with a singular instance */ > TOPO_ROOT_DOMAIN, > TOPO_MAX_DOMAIN, > }; Now this begs the obvious question what the actual meaning of these domains is and what's their relevance for the kernel. It's probably undisputed what SMT/CORE mean and what their relevance is. The PKG/DIE domains are pretty clear too. Now we have: MODULE (Intel only) TILE Intel, AMD names it "Complex" So here are the questions: - is TILE to "Complex" the proper mapping? - which information is conveyed by MODULE and TILE? - Are these really different between AMD and Intel or is this some naming convention issue which needs to be resolved? Thanks, tglx