On 01/03/2023 03:42, Baoquan He wrote: > diff --git a/drivers/net/ethernet/sfc/io.h b/drivers/net/ethernet/sfc/io.h > index 30439cc83a89..07f99ad14bf3 100644 > --- a/drivers/net/ethernet/sfc/io.h > +++ b/drivers/net/ethernet/sfc/io.h > @@ -70,7 +70,7 @@ > */ > #ifdef CONFIG_X86_64 > /* PIO is a win only if write-combining is possible */ > -#ifdef ARCH_HAS_IOREMAP_WC > +#ifdef ioremap_wc > #define EFX_USE_PIO 1 > #endif > #endif So I don't know how valid what we're doing here is... > diff --git a/include/asm-generic/iomap.h b/include/asm-generic/iomap.h > index 08237ae8b840..196087a8126e 100644 > --- a/include/asm-generic/iomap.h > +++ b/include/asm-generic/iomap.h > @@ -93,15 +93,15 @@ extern void __iomem *ioport_map(unsigned long port, unsigned int nr); > extern void ioport_unmap(void __iomem *); > #endif > > -#ifndef ARCH_HAS_IOREMAP_WC > +#ifndef ioremap_wc > #define ioremap_wc ioremap > #endif ... but it looks like this will break it, since in sfc/io.h `#ifdef ioremap_wc` will always be true (if I'm correctly understanding what we get via #include <linux/io.h>, which I'm probably not because asm includes always confuse me). I.e. we're not just interested in "can code that calls ioremap_wc compile?", we care about whether we actually get WC, because we're making an optimisation decision based on it.