From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) (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 D7A661DF744; Thu, 17 Oct 2024 16:59:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.176.79.56 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729184393; cv=none; b=LG7LDeg7n2wZgwrPl+dIa+FPov4cjpWomF5QmGsEP8JpwOfy0vzPECU2IkiTquK/BhJgTFraYNGtnlQdae06b+KYgCZdMq+5DQ1q1ikCfIh1zz3YOcExkOJU61X1CT6EgGtAgkcX2gvCeVL+Rwx7IkLWfDCsUmPU3e7lmxQPCe8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729184393; c=relaxed/simple; bh=ARY6QB40hS8SjbiQQrQF8tLLS7fueNq5q3sRfcztBfo=; h=Date:From:To:CC:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=ljL9GoL3GP6PueP1XcYfliTk24Q17bmB9ylg6eTxMVYHxbQGHqCBZCXhpjXcWuDAkxRmpoT6wsYCTMzli+ltvb8/khAqvuKoXMUiw6lmqXB54f1BSuLqrtAhbFX5PEmcZcI7ITYpdsEbc/aeIGda77h3Y3rpU1Zh67PA+5qTWk8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=Huawei.com; spf=pass smtp.mailfrom=huawei.com; arc=none smtp.client-ip=185.176.79.56 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=Huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Received: from mail.maildlp.com (unknown [172.18.186.216]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4XTvCr6hG1z6K6kS; Fri, 18 Oct 2024 00:58:00 +0800 (CST) Received: from frapeml500008.china.huawei.com (unknown [7.182.85.71]) by mail.maildlp.com (Postfix) with ESMTPS id 871F7140B67; Fri, 18 Oct 2024 00:59:45 +0800 (CST) Received: from localhost (10.126.174.164) by frapeml500008.china.huawei.com (7.182.85.71) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.1.2507.39; Thu, 17 Oct 2024 18:59:44 +0200 Date: Thu, 17 Oct 2024 17:59:42 +0100 From: Jonathan Cameron To: "Luck, Tony" CC: "Jiang, Dave" , "linux-cxl@vger.kernel.org" , "linux-acpi@vger.kernel.org" , "rafael@kernel.org" , "bp@alien8.de" , "Williams, Dan J" , "dave@stgolabs.net" , "Schofield, Alison" , "Weiny, Ira" Subject: Re: [RFC PATCH 4/6] acpi/hmat: Add helper functions to provide extended linear cache translation Message-ID: <20241017175942.000072b4@Huawei.com> In-Reply-To: References: <20240927142108.1156362-1-dave.jiang@intel.com> <20240927142108.1156362-5-dave.jiang@intel.com> <20241017173326.0000191a@Huawei.com> Organization: Huawei Technologies Research and Development (UK) Ltd. X-Mailer: Claws Mail 4.1.0 (GTK 3.24.33; x86_64-w64-mingw32) Precedence: bulk X-Mailing-List: linux-acpi@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-ClientProxiedBy: lhrpeml500002.china.huawei.com (7.191.160.78) To frapeml500008.china.huawei.com (7.182.85.71) On Thu, 17 Oct 2024 16:46:35 +0000 "Luck, Tony" wrote: > > What does the I/O hole correspond to in the system? > > PCIe mmio mapped space. 32-bit devices must have addresses below 4G > so X86 systems have a physical memory map that looks like: > > 0 - 2G: RAM > 2G-4G: MMIO > 4G-end of memory: RAM > end of memory-infinity: 64-bit MMIO > > Depending on how much MMIO there is different systems put the > dividing line at other addresses than 2G. Ah, thanks. So this weird cache setup might be not quite linear module N aliases as described in the ACPI spec (System vs host physical addresses I guess). Had wrong mental model :( Ouch. > > -Tony >