From patchwork Fri Jul 15 14:25:46 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: =?utf-8?b?SsO8cmdlbiBHcm/Dnw==?= X-Patchwork-Id: 12919322 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 D8C2CC433EF for ; Fri, 15 Jul 2022 14:25:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232893AbiGOOZ4 (ORCPT ); Fri, 15 Jul 2022 10:25:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49332 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229846AbiGOOZy (ORCPT ); Fri, 15 Jul 2022 10:25:54 -0400 Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.220.28]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 05A865D0C9; Fri, 15 Jul 2022 07:25:54 -0700 (PDT) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id B7E1134DD1; Fri, 15 Jul 2022 14:25:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1657895152; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=Tle2lhJhQp2g1mDXUt7ZR3944PM4JXbq65HXWxNQb9s=; b=Q72RTBuD7k4s6+lQaBTvP7XBaVckub1f8rXxhmEYqk15ECh+YhcXULfMBDLX5wgm3sUevt Sy7CZREhmcgK5mvyF/r2pt77ayU0bXXrwGbDnpImxAQ+rgRtXXPu8V7PVQ1DGDimwk99Ch U5mq93BlCh5EhiuDrT92+X1e6paGPnE= Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 2F88F13754; Fri, 15 Jul 2022 14:25:52 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id wkAkCvB40WK+QQAAMHmgww (envelope-from ); Fri, 15 Jul 2022 14:25:52 +0000 From: Juergen Gross To: xen-devel@lists.xenproject.org, x86@kernel.org, linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org Cc: brchuckz@netscape.net, jbeulich@suse.com, Juergen Gross , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , "H. Peter Anvin" , "# 5 . 17" , "Rafael J. Wysocki" , Pavel Machek , Andy Lutomirski , Peter Zijlstra , Boris Ostrovsky Subject: [PATCH 0/3] x86: make pat and mtrr independent from each other Date: Fri, 15 Jul 2022 16:25:46 +0200 Message-Id: <20220715142549.25223-1-jgross@suse.com> X-Mailer: git-send-email 2.35.3 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org Today PAT can't be used without MTRR being available, unless MTRR is at least configured via CONFIG_MTRR and the system is running as Xen PV guest. In this case PAT is automatically available via the hypervisor, but the PAT MSR can't be modified by the kernel and MTRR is disabled. As an additional complexity the availability of PAT can't be queried via pat_enabled() in the Xen PV case, as the lack of MTRR will set PAT to be disabled. This leads to some drivers believing that not all cache modes are available, resulting in failures or degraded functionality. The same applies to a kernel built with no MTRR support: it won't allow to use the PAT MSR, even if there is no technical reason for that, other than setting up PAT on all cpus the same way (which is a requirement of the processor's cache management) is relying on some MTRR specific code. Fix all of that by: - moving the function needed by PAT from MTRR specific code one level up - adding a PAT indirection layer supporting the 3 cases "no or disabled PAT", "PAT under kernel control", and "PAT under Xen control" - removing the dependency of PAT on MTRR Juergen Gross (3): x86: move some code out of arch/x86/kernel/cpu/mtrr x86: add wrapper functions for mtrr functions handling also pat x86: decouple pat and mtrr handling arch/x86/include/asm/memtype.h | 13 ++- arch/x86/include/asm/mtrr.h | 27 ++++-- arch/x86/include/asm/processor.h | 10 +++ arch/x86/kernel/cpu/common.c | 123 +++++++++++++++++++++++++++- arch/x86/kernel/cpu/mtrr/generic.c | 90 ++------------------ arch/x86/kernel/cpu/mtrr/mtrr.c | 58 ++++--------- arch/x86/kernel/cpu/mtrr/mtrr.h | 1 - arch/x86/kernel/setup.c | 12 +-- arch/x86/kernel/smpboot.c | 8 +- arch/x86/mm/pat/memtype.c | 127 +++++++++++++++++++++-------- arch/x86/power/cpu.c | 2 +- arch/x86/xen/enlighten_pv.c | 4 + 12 files changed, 289 insertions(+), 186 deletions(-)