Re: [Xen-devel] [PATCH v1 04/47] pci: add pci_ioremap_wc_bar()
From: Konrad Rzeszutek Wilk <hidden>
Date: 2015-03-25 20:04:33
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On Fri, Mar 20, 2015 at 04:17:54PM -0700, Luis R. Rodriguez wrote:
From: "Luis R. Rodriguez" <redacted> This lets drivers take advanate of PAT when available. This
s/advanate/advantage/
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() (de33c442e)
Please mention the title of the patch too: "x86 PAT: fix performance drop for glx, use UC minus for ioremap(), ioremap_nocache() and pci_mmap_page_range()"
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Cc: Suresh Siddha <redacted> Cc: Venkatesh Pallipadi <redacted> Cc: Ingo Molnar <redacted> Cc: Thomas Gleixner <redacted> Cc: Juergen Gross <jgross@suse.com> Cc: Daniel Vetter <redacted> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Dave Airlie <airlied@redhat.com> Cc: Antonino Daplas <adaplas@gmail.com> Cc: Jean-Christophe Plagniol-Villard <redacted> Cc: Tomi Valkeinen <redacted> Cc: linux-fbdev@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Luis R. Rodriguez <redacted> --- 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 81f06e8..6afd507 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c@@ -137,6 +137,20 @@ void __iomem *pci_ioremap_bar(struct pci_dev *pdev, int bar) pci_resource_len(pdev, bar)); } 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);
Would it be better to use dev_warn ? That way you can see which BDF it is? Thought WARN will give a nice stack-trace that should easily point to the driver so perhaps not.. Either way - up to you.
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+ 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 48diff --git a/include/linux/pci.h b/include/linux/pci.h index 211e9da..c235b09 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h@@ -1667,6 +1667,7 @@ 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_enable_sriov(struct pci_dev *dev, int nr_virtfn);-- 2.3.2.209.gd67f9d5.dirty _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel