From patchwork Tue May 3 13:22:07 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: 12835800 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 gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 9A386C433FE for ; Tue, 3 May 2022 13:22:16 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 2DDA810FFFC; Tue, 3 May 2022 13:22:13 +0000 (UTC) Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.220.29]) by gabe.freedesktop.org (Postfix) with ESMTPS id 6C84710FFF8; Tue, 3 May 2022 13:22:12 +0000 (UTC) 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-out2.suse.de (Postfix) with ESMTPS id F0C3B1F749; Tue, 3 May 2022 13:22:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1651584131; 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: in-reply-to:in-reply-to:references:references; bh=vpkV8V5Y+6Vb55bRfQcavzTocu4t1BaNWLiM7KsOY1Y=; b=ubKL3UxTpmVXRWOdBpBxP1Blc7iCSFjpprMuVtEqjUkNxvt5KgAL1kIcTNjkGyUG/j5v7g eP8pHFW6Rm0suxVOYcYDsv/lL+qGJmUY9KnmCMOK0w391MnS/4uG7jTU1+tHyDmy49tmTD f4U0Tn/Uxnm7o0c9V2tpCWb8OLMoFfk= 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 6806513ABE; Tue, 3 May 2022 13:22:10 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id iNYLGIIscWIASAAAMHmgww (envelope-from ); Tue, 03 May 2022 13:22:10 +0000 From: Juergen Gross To: xen-devel@lists.xenproject.org, x86@kernel.org, linux-kernel@vger.kernel.org, intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org Date: Tue, 3 May 2022 15:22:07 +0200 Message-Id: <20220503132207.17234-3-jgross@suse.com> X-Mailer: git-send-email 2.35.3 In-Reply-To: <20220503132207.17234-1-jgross@suse.com> References: <20220503132207.17234-1-jgross@suse.com> MIME-Version: 1.0 Subject: [Intel-gfx] [PATCH 2/2] x86/pat: add functions to query specific cache mode availability X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Juergen Gross , Andy Lutomirski , Peter Zijlstra , Dave Hansen , David Airlie , Rodrigo Vivi , Ingo Molnar , Borislav Petkov , jbeulich@suse.com, "H. Peter Anvin" , Thomas Gleixner Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" Some drivers are using pat_enabled() in order to test availability of special caching modes (WC and UC-). This will lead to false negatives in case the system was booted e.g. with the "nopat" variant and the BIOS did setup the PAT MSR supporting the queried mode, or if the system is running as a Xen PV guest. Add test functions for those caching modes instead and use them at the appropriate places. For symmetry reasons export the already existing x86_has_pat_wp() for modules, too. Fixes: bdd8b6c98239 ("drm/i915: replace X86_FEATURE_PAT with pat_enabled()") Fixes: ae749c7ab475 ("PCI: Add arch_can_pci_mmap_wc() macro") Signed-off-by: Juergen Gross --- arch/x86/include/asm/memtype.h | 2 ++ arch/x86/include/asm/pci.h | 2 +- arch/x86/mm/init.c | 25 +++++++++++++++++++++--- drivers/gpu/drm/i915/gem/i915_gem_mman.c | 8 ++++---- 4 files changed, 29 insertions(+), 8 deletions(-) diff --git a/arch/x86/include/asm/memtype.h b/arch/x86/include/asm/memtype.h index 9ca760e430b9..d00e0be854d4 100644 --- a/arch/x86/include/asm/memtype.h +++ b/arch/x86/include/asm/memtype.h @@ -25,6 +25,8 @@ extern void memtype_free_io(resource_size_t start, resource_size_t end); extern bool pat_pfn_immune_to_uc_mtrr(unsigned long pfn); bool x86_has_pat_wp(void); +bool x86_has_pat_wc(void); +bool x86_has_pat_uc_minus(void); enum page_cache_mode pgprot2cachemode(pgprot_t pgprot); #endif /* _ASM_X86_MEMTYPE_H */ diff --git a/arch/x86/include/asm/pci.h b/arch/x86/include/asm/pci.h index f3fd5928bcbb..a5742268dec1 100644 --- a/arch/x86/include/asm/pci.h +++ b/arch/x86/include/asm/pci.h @@ -94,7 +94,7 @@ int pcibios_set_irq_routing(struct pci_dev *dev, int pin, int irq); #define HAVE_PCI_MMAP -#define arch_can_pci_mmap_wc() pat_enabled() +#define arch_can_pci_mmap_wc() x86_has_pat_wc() #define ARCH_GENERIC_PCI_MMAP_RESOURCE #ifdef CONFIG_PCI diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c index 71e182ebced3..b6431f714dc2 100644 --- a/arch/x86/mm/init.c +++ b/arch/x86/mm/init.c @@ -77,12 +77,31 @@ static uint8_t __pte2cachemode_tbl[8] = { [__pte2cm_idx(_PAGE_PWT | _PAGE_PCD | _PAGE_PAT)] = _PAGE_CACHE_MODE_UC, }; -/* Check that the write-protect PAT entry is set for write-protect */ +static bool x86_has_pat_mode(unsigned int mode) +{ + return __pte2cachemode_tbl[__cachemode2pte_tbl[mode]] == mode; +} + +/* Check that PAT supports write-protect */ bool x86_has_pat_wp(void) { - return __pte2cachemode_tbl[__cachemode2pte_tbl[_PAGE_CACHE_MODE_WP]] == - _PAGE_CACHE_MODE_WP; + return x86_has_pat_mode(_PAGE_CACHE_MODE_WP); +} +EXPORT_SYMBOL_GPL(x86_has_pat_wp); + +/* Check that PAT supports WC */ +bool x86_has_pat_wc(void) +{ + return x86_has_pat_mode(_PAGE_CACHE_MODE_WC); +} +EXPORT_SYMBOL_GPL(x86_has_pat_wc); + +/* Check that PAT supports UC- */ +bool x86_has_pat_uc_minus(void) +{ + return x86_has_pat_mode(_PAGE_CACHE_MODE_UC_MINUS); } +EXPORT_SYMBOL_GPL(x86_has_pat_uc_minus); enum page_cache_mode pgprot2cachemode(pgprot_t pgprot) { diff --git a/drivers/gpu/drm/i915/gem/i915_gem_mman.c b/drivers/gpu/drm/i915/gem/i915_gem_mman.c index 0c5c43852e24..f43ecf3f63eb 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_mman.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_mman.c @@ -76,7 +76,7 @@ i915_gem_mmap_ioctl(struct drm_device *dev, void *data, if (args->flags & ~(I915_MMAP_WC)) return -EINVAL; - if (args->flags & I915_MMAP_WC && !pat_enabled()) + if (args->flags & I915_MMAP_WC && !x86_has_pat_wc()) return -ENODEV; obj = i915_gem_object_lookup(file, args->handle); @@ -757,7 +757,7 @@ i915_gem_dumb_mmap_offset(struct drm_file *file, if (HAS_LMEM(to_i915(dev))) mmap_type = I915_MMAP_TYPE_FIXED; - else if (pat_enabled()) + else if (x86_has_pat_wc()) mmap_type = I915_MMAP_TYPE_WC; else if (!i915_ggtt_has_aperture(to_gt(i915)->ggtt)) return -ENODEV; @@ -813,7 +813,7 @@ i915_gem_mmap_offset_ioctl(struct drm_device *dev, void *data, break; case I915_MMAP_OFFSET_WC: - if (!pat_enabled()) + if (!x86_has_pat_wc()) return -ENODEV; type = I915_MMAP_TYPE_WC; break; @@ -823,7 +823,7 @@ i915_gem_mmap_offset_ioctl(struct drm_device *dev, void *data, break; case I915_MMAP_OFFSET_UC: - if (!pat_enabled()) + if (!x86_has_pat_uc_minus()) return -ENODEV; type = I915_MMAP_TYPE_UC; break;