From c43996f4001de629af4a4d6713782e883677e5b9 Mon Sep 17 00:00:00 2001 From: "Luis R. Rodriguez" Date: Mon, 24 Aug 2015 12:13:23 -0700 Subject: [PATCH] PCI: Add pci_ioremap_wc_bar() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This lets drivers take advantage of PAT when available. It should help with the transition of converting video drivers over to ioremap_wc() to help with the goal of eventually using _PAGE_CACHE_UC over _PAGE_CACHE_UC_MINUS on x86 on ioremap_nocache(), see: de33c442ed2a ("x86 PAT: fix performance drop for glx, use UC minus for ioremap(), ioremap_nocache() and pci_mmap_page_range()") Signed-off-by: Luis R. Rodriguez Signed-off-by: Borislav Petkov Acked-by: Arnd Bergmann Cc: Cc: Andrew Morton Cc: Andy Lutomirski Cc: Antonino Daplas Cc: Bjorn Helgaas Cc: Daniel Vetter Cc: Dave Airlie Cc: Davidlohr Bueso Cc: H. Peter Anvin Cc: Jean-Christophe Plagniol-Villard Cc: Juergen Gross Cc: Linus Torvalds Cc: Mel Gorman Cc: Peter Zijlstra Cc: Suresh Siddha Cc: Thomas Gleixner Cc: Tomi Valkeinen Cc: Toshi Kani Cc: Ville Syrjälä Cc: Vlastimil Babka Cc: airlied@linux.ie Cc: benh@kernel.crashing.org Cc: dan.j.williams@intel.com Cc: konrad.wilk@oracle.com Cc: linux-fbdev@vger.kernel.org Cc: linux-pci@vger.kernel.org Cc: mst@redhat.com Cc: vinod.koul@intel.com Cc: xen-devel@lists.xensource.com Link: http://lkml.kernel.org/r/1440443613-13696-2-git-send-email-mcgrof@do-not-panic.com Signed-off-by: Ingo Molnar --- drivers/pci/pci.c | 14 ++++++++++++++ include/linux/pci.h | 1 + 2 files changed, 15 insertions(+) diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 0008c950452c..fdae37b473f8 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -138,6 +138,20 @@ void __iomem *pci_ioremap_bar(struct pci_dev *pdev, int bar) return ioremap_nocache(res->start, resource_size(res)); } EXPORT_SYMBOL_GPL(pci_ioremap_bar); + +void __iomem *pci_ioremap_wc_bar(struct pci_dev *pdev, int bar) +{ + /* + * Make sure the BAR is actually a memory resource, not an IO resource + */ + if (!(pci_resource_flags(pdev, bar) & IORESOURCE_MEM)) { + WARN_ON(1); + return NULL; + } + return ioremap_wc(pci_resource_start(pdev, bar), + pci_resource_len(pdev, bar)); +} +EXPORT_SYMBOL_GPL(pci_ioremap_wc_bar); #endif #define PCI_FIND_CAP_TTL 48 diff --git a/include/linux/pci.h b/include/linux/pci.h index 8a0321a8fb59..985dd392e5f2 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -1661,6 +1661,7 @@ static inline void pci_mmcfg_late_init(void) { } int pci_ext_cfg_avail(void); void __iomem *pci_ioremap_bar(struct pci_dev *pdev, int bar); +void __iomem *pci_ioremap_wc_bar(struct pci_dev *pdev, int bar); #ifdef CONFIG_PCI_IOV int pci_iov_virtfn_bus(struct pci_dev *dev, int id); -- GitLab