From patchwork Wed Mar 15 20:42:26 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Woodhouse X-Patchwork-Id: 9626653 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id EB725604A9 for ; Wed, 15 Mar 2017 20:42:49 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id DC62A2808F for ; Wed, 15 Mar 2017 20:42:49 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id D0681284CB; Wed, 15 Mar 2017 20:42:49 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.9 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID autolearn=ham version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [65.50.211.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 51B762808F for ; Wed, 15 Mar 2017 20:42:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender:Content-Type:Cc: List-Subscribe:List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id: Mime-Version:Date:To:From:Subject:Message-ID:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To: References:List-Owner; bh=GPWcWVAyu7ZReQPWtEB8Mzq8f5tb9B3ovG2e0dbr2yE=; b=j1p x30WmZmAlFY/2TNHJdIa5ooIU9v3komSWjWmQ/LAeREKyQ3XMoK96Sme9/UecHcJ6BhJohU0AW3ik odO4oC/Sib4ggrIeza3ivt6I9fT8RLW97xNwBsjfhg7FYptG8feg1ywJYs40iD7N8RL7vjkxPR5VH DhkEcnUQweMpIBl7oQ5NnFWB6bvweUU2uJT83jeXpdt+8XYt8ejvjMa6XETnpHRzTjhtbVscLbZHd hCachMT6Eg+hEnlGDzvQCd2kBgdsP64A5gRRxplG1BE/JZ0YtJ+cFydrACQ+RR3cpgu8HeOKrLetZ jTlFjjjq+F1UGWHxZPEvPsicnpgAlkA==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.87 #1 (Red Hat Linux)) id 1coFkq-0001FB-8s; Wed, 15 Mar 2017 20:42:44 +0000 Received: from casper.infradead.org ([2001:770:15f::2]) by bombadil.infradead.org with esmtps (Exim 4.87 #1 (Red Hat Linux)) id 1coFkb-0000v2-Et for linux-arm-kernel@bombadil.infradead.org; Wed, 15 Mar 2017 20:42:29 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Mime-Version:Content-Type:Date:Cc:To: From:Subject:Message-ID:Sender:Reply-To:Content-Transfer-Encoding:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:In-Reply-To:References:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=uH5HI4pBUmeBF7L2Fr7aIdz9XfrheX3tha1qdmvsWys=; b=EtpRc8I3HV7AtbckYltgllUyma AHZ39WEcbmQ3ncVk7cSElPnru5YqnEvgrTi6NVqbCuaNDltU0Dkq1neUuFBKw7Y3k4IPmnfigVjPD iVDjL+BulKyYJcJQO3rJFiO0wa/QDO19Vk7iwsucYhUe7nYX9+ldwlkPbWKVerSkDDoxvNQfsbB02 mlrXRF+f5c6Tqr/SAY3vrgUb70bwKWn7aYeEOOjtmFOwR/mr9UDQJ/bMT3WBbqjOopalOgwQJQBp0 rRsffH6mwaH7Mdc8huzE1IKCwzhlzkTYLZCBkqw0ul4z2QRADADxVezsEzqDnjN6pf2w/R3ntLpVs f64a2IQw==; Received: from i7.infradead.org ([90.155.92.213]) by casper.infradead.org with esmtpsa (Exim 4.87 #1 (Red Hat Linux)) id 1coFkZ-0003oH-GO; Wed, 15 Mar 2017 20:42:27 +0000 Message-ID: <1489610546.86622.20.camel@infradead.org> Subject: [PATCH v2 2/4] pci: Add arch_can_pci_mmap_wc() macro From: David Woodhouse To: linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Date: Wed, 15 Mar 2017 20:42:26 +0000 X-Mailer: Evolution 3.22.4 (3.22.4-2.fc25) Mime-Version: 1.0 X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , Catalin Marinas , Will Deacon Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP From: David Woodhouse Most of the almost-identical versions of pci_mmap_page_range() silently ignore the 'write_combine' argument and give uncached mappings. Yet we allow the PCIIOC_WRITE_COMBINE ioctl in /proc/bus/pci, expose the 'resourceX_wc' file in sysfs, and allow an attempted mapping to apparently succeed. To fix this, introduce a macro arch_can_pci_mmap_wc() which indicates whether the platform can do a write-combining mapping. On x86 this ends up being pat_enabled(), while the few other platforms that support it can just set it to a literal '1'. Signed-off-by: David Woodhouse --- Documentation/filesystems/sysfs-pci.txt | 4 ++++ arch/arm64/include/asm/pci.h | 1 + arch/ia64/include/asm/pci.h | 2 ++ arch/powerpc/include/asm/pci.h | 5 +++-- arch/x86/include/asm/pci.h | 2 ++ arch/xtensa/include/asm/pci.h | 6 +++++- arch/xtensa/kernel/pci.c | 2 +- drivers/pci/pci-sysfs.c | 6 ++++-- drivers/pci/proc.c | 17 ++++++++++------- 9 files changed, 32 insertions(+), 13 deletions(-) diff --git a/Documentation/filesystems/sysfs-pci.txt b/Documentation/filesystems/sysfs-pci.txt index 6ea1ced..25b7f1c 100644 --- a/Documentation/filesystems/sysfs-pci.txt +++ b/Documentation/filesystems/sysfs-pci.txt @@ -117,6 +117,10 @@ code must define HAVE_PCI_MMAP and provide a pci_mmap_page_range function. Platforms are free to only support subsets of the mmap functionality, but useful return codes should be provided. +Platforms which support write-combining maps of PCI resources must define +arch_can_pci_mmap_wc() which shall evaluate to non-zero at runtime when +write-combining is permitted. + Legacy resources are protected by the HAVE_PCI_LEGACY define. Platforms wishing to support legacy functionality should define it and provide pci_legacy_read, pci_legacy_write and pci_mmap_legacy_page_range functions. diff --git a/arch/arm64/include/asm/pci.h b/arch/arm64/include/asm/pci.h index f73734f..53b1541 100644 --- a/arch/arm64/include/asm/pci.h +++ b/arch/arm64/include/asm/pci.h @@ -38,6 +38,7 @@ static inline int pci_proc_domain(struct pci_bus *bus) #endif /* CONFIG_PCI */ #define HAVE_PCI_MMAP +#define arch_can_pci_mmap_wc() 1 extern int pci_mmap_page_range(struct pci_dev *dev, struct vm_area_struct *vma, enum pci_mmap_state mmap_state, int write_combine); diff --git a/arch/ia64/include/asm/pci.h b/arch/ia64/include/asm/pci.h index c0835b0..6283758 100644 --- a/arch/ia64/include/asm/pci.h +++ b/arch/ia64/include/asm/pci.h @@ -51,6 +51,8 @@ extern unsigned long ia64_max_iommu_merge_mask; #define PCI_DMA_BUS_IS_PHYS (ia64_max_iommu_merge_mask == ~0UL) #define HAVE_PCI_MMAP +#define arch_can_pci_mmap_wc() 1 + extern int pci_mmap_page_range (struct pci_dev *dev, struct vm_area_struct *vma, enum pci_mmap_state mmap_state, int write_combine); #define HAVE_PCI_LEGACY diff --git a/arch/powerpc/include/asm/pci.h b/arch/powerpc/include/asm/pci.h index 93eded8..b5b68c6 100644 --- a/arch/powerpc/include/asm/pci.h +++ b/arch/powerpc/include/asm/pci.h @@ -81,8 +81,9 @@ struct vm_area_struct; int pci_mmap_page_range(struct pci_dev *pdev, struct vm_area_struct *vma, enum pci_mmap_state mmap_state, int write_combine); -/* Tell drivers/pci/proc.c that we have pci_mmap_page_range() */ -#define HAVE_PCI_MMAP 1 +/* Tell drivers/pci/proc.c that we have pci_mmap_page_range() and it does WC */ +#define HAVE_PCI_MMAP 1 +#define arch_can_pci_mmap_wc() 1 extern int pci_legacy_read(struct pci_bus *bus, loff_t port, u32 *val, size_t count); diff --git a/arch/x86/include/asm/pci.h b/arch/x86/include/asm/pci.h index 1411dbe..f6e22c2 100644 --- a/arch/x86/include/asm/pci.h +++ b/arch/x86/include/asm/pci.h @@ -7,6 +7,7 @@ #include #include #include +#include #include #ifdef __KERNEL__ @@ -102,6 +103,7 @@ 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() extern int pci_mmap_page_range(struct pci_dev *dev, struct vm_area_struct *vma, enum pci_mmap_state mmap_state, int write_combine); diff --git a/arch/xtensa/include/asm/pci.h b/arch/xtensa/include/asm/pci.h index 5d6bd93..f106879 100644 --- a/arch/xtensa/include/asm/pci.h +++ b/arch/xtensa/include/asm/pci.h @@ -51,7 +51,11 @@ int pci_mmap_page_range(struct pci_dev *pdev, struct vm_area_struct *vma, enum pci_mmap_state mmap_state, int write_combine); /* Tell drivers/pci/proc.c that we have pci_mmap_page_range() */ -#define HAVE_PCI_MMAP 1 +#define HAVE_PCI_MMAP 1 + +/* This was wrapped in #if 0 since the first merge of xtensa support... +#define arch_can_pci_mmap_wc() 1 +*/ #endif /* __KERNEL__ */ diff --git a/arch/xtensa/kernel/pci.c b/arch/xtensa/kernel/pci.c index b848cc3..c5944d3 100644 --- a/arch/xtensa/kernel/pci.c +++ b/arch/xtensa/kernel/pci.c @@ -345,7 +345,7 @@ __pci_mmap_set_pgprot(struct pci_dev *dev, struct vm_area_struct *vma, /* Set to write-through */ prot = (prot & _PAGE_CA_MASK) | _PAGE_CA_WT; -#if 0 +#ifdef arch_can_pci_mmap_wc if (!write_combine) prot |= _PAGE_WRITETHRU; #endif diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c index 25d010d..e0474f3 100644 --- a/drivers/pci/pci-sysfs.c +++ b/drivers/pci/pci-sysfs.c @@ -1206,10 +1206,12 @@ static int pci_create_resource_files(struct pci_dev *pdev) continue; retval = pci_create_attr(pdev, i, 0); +#ifdef arch_can_pci_mmap_wc /* for prefetchable resources, create a WC mappable file */ - if (!retval && pdev->resource[i].flags & IORESOURCE_PREFETCH) + if (!retval && arch_can_pci_mmap_wc() && + pdev->resource[i].flags & IORESOURCE_PREFETCH) retval = pci_create_attr(pdev, i, 1); - +#endif if (retval) { pci_remove_resource_files(pdev); return retval; diff --git a/drivers/pci/proc.c b/drivers/pci/proc.c index f82710a..5cd960c 100644 --- a/drivers/pci/proc.c +++ b/drivers/pci/proc.c @@ -209,15 +209,18 @@ static long proc_bus_pci_ioctl(struct file *file, unsigned int cmd, fpriv->mmap_state = pci_mmap_mem; break; +#ifdef arch_can_pci_mmap_wc case PCIIOC_WRITE_COMBINE: - if (arg) - fpriv->write_combine = 1; - else - fpriv->write_combine = 0; - break; - + if (arch_can_pci_mmap_wc()) { + if (arg) + fpriv->write_combine = 1; + else + fpriv->write_combine = 0; + break; + } + /* If arch decided it can't, fall through... */ +#endif /* arch_can_pci_mmap_wc */ #endif /* HAVE_PCI_MMAP */ - default: ret = -EINVAL; break;