On Wed, Mar 25, 2015 at 04:03:46PM -0400, Konrad Rzeszutek Wilk wrote: > On Fri, Mar 20, 2015 at 04:17:54PM -0700, Luis R. Rodriguez wrote: > > From: "Luis R. Rodriguez" <[email protected]> > > > > This lets drivers take advanate of PAT when available. This > > s/advanate/advantage/
Amended. > > 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()" Added. > > > > Cc: Suresh Siddha <[email protected]> > > Cc: Venkatesh Pallipadi <[email protected]> > > Cc: Ingo Molnar <[email protected]> > > Cc: Thomas Gleixner <[email protected]> > > Cc: Juergen Gross <[email protected]> > > Cc: Daniel Vetter <[email protected]> > > Cc: Andy Lutomirski <[email protected]> > > Cc: Dave Airlie <[email protected]> > > Cc: Antonino Daplas <[email protected]> > > Cc: Jean-Christophe Plagniol-Villard <[email protected]> > > Cc: Tomi Valkeinen <[email protected]> > > Cc: [email protected] > > Cc: [email protected] > > Signed-off-by: Luis R. Rodriguez <[email protected]> > > --- > > 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. I'm sticking to the style and use as with pci_ioremap_bar(). Whatever we pick we should make both use the same. More information is always better and since we do have dev_warn(), it would be nice to use that however within its use on both pci_ioremap_wc_bar() and pci_ioremap_bar() we have a use of the pdev with pci_resource_flags() and I believe if pdev is NULL we'd get a NULL dereference (dev_driver_string() is used), so it would seem it might be best to stick with a simple WARN_ON(). Arjan, any preference? Obviously if pdev is NULL your driver is dumb but as folks develop drivers this should be expected. Luis -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
