Re: [PATCH v1 04/47] pci: add pci_ioremap_wc_bar()

Andy Lutomirski
2015-03-20T23:50:59Z

On Fri, Mar 20, 2015 at 4:17 PM, Luis R. Rodriguez
<mcgrof@do-not-panic.com> wrote:
> From: "Luis R. Rodriguez" <mcgrof@suse.com>
>
> This lets drivers take advanate 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)
>
> Cc: Suresh Siddha <suresh.b.siddha@intel.com>
> Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
> Cc: Ingo Molnar <mingo@elte.hu>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Cc: Juergen Gross <jgross@suse.com>
> Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
> Cc: Andy Lutomirski <luto@amacapital.net>
> Cc: Dave Airlie <airlied@redhat.com>
> Cc: Antonino Daplas <adaplas@gmail.com>
> Cc: Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com>
> Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
> Cc: linux-fbdev@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
> Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com>
> ---
> 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);
> + return NULL;
> + }

if (WARN_ON(...))?

--Andy