On Tue, Apr 21, 2015 at 01:20:31PM -0700, Luis R. Rodriguez wrote:
> From: "Luis R. Rodriguez" <mcg...@suse.com>
>
> This lets drivers take advantage of PAT when available. This
> 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 titled "x86 PAT: fix performance
> drop for glx, use UC minus for ioremap(), ioremap_nocache() and
> pci_mmap_page_range()")
>
> Cc: Toshi Kani <toshi.k...@hp.com>
> Cc: Bjorn Helgaas <bhelg...@google.com>
> Cc: Suresh Siddha <sbsid...@gmail.com>
> Cc: Ingo Molnar <mi...@elte.hu>
> Cc: Thomas Gleixner <t...@linutronix.de>
> Cc: Juergen Gross <jgr...@suse.com>
> Cc: Daniel Vetter <daniel.vet...@ffwll.ch>
> Cc: Andy Lutomirski <l...@amacapital.net>
> Cc: Dave Airlie <airl...@redhat.com>
> Cc: Antonino Daplas <adap...@gmail.com>
> Cc: Jean-Christophe Plagniol-Villard <plagn...@jcrosoft.com>
> Cc: Tomi Valkeinen <tomi.valkei...@ti.com>
> Cc: Ville Syrjälä <syrj...@sci.fi>
> Cc: Mel Gorman <mgor...@suse.de>
> Cc: Vlastimil Babka <vba...@suse.cz>
> Cc: Borislav Petkov <b...@suse.de>
> Cc: Davidlohr Bueso <dbu...@suse.de>
> Cc: linux-fb...@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
> Signed-off-by: Luis R. Rodriguez <mcg...@suse.com>
I don't have any objection to this, and I can apply the follow-on patches
as well, given the appropriate acks and prerequisite patches (ioremap_wc()
implementation).
> ---
> 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 687af72..fd14f10 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 bc50bb0..490ca41 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_iov_virtfn_bus(struct pci_dev *dev, int id);
> --
> 2.3.2.209.gd67f9d5.dirty
>
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
