Hi Christophe, Arnd, On 02/17/23 at 01:46pm, Christophe Leroy wrote: > > > Le 17/02/2023 à 14:31, Baoquan He a écrit : > > On 02/16/23 at 04:18pm, Arnd Bergmann wrote: > >> On Thu, Feb 16, 2023, at 16:02, Baoquan He wrote: > >>> On 02/16/23 at 01:50pm, Matthew Wilcox wrote: > >>> It's not if including asm-generic/iomap.h. The ARCH_HAS_IOREMAP_xx is to > >>> avoid redefinition there. > >>> > >>> include/asm-generic/iomap.h: > >>> ---- > >>> #ifndef ARCH_HAS_IOREMAP_WC > >>> #define ioremap_wc ioremap > >>> #endif > >> > >> I'd change that to the usual '#ifndef ioremap_wc' in that case. > > > > Not sure if I got you. Kill all ARCH_HAS_IOREMAP_xxx in kernel? If yes, > > sounds like a good idea. > > > > At least kill that one at the first place in your series, and then the > other ones in a follow-up series maybe. I made a patch to remove all ARCH_HAS_IOREMAP_xx macros in architectures and the ifdeffery of ARCH_HAS_IOREMAP_xx in asm-generic/iomap.h. But the change will cause building error as below. Becuase we usually have '#include <asm-generic/iomap.h>' at the beginning of arch/xx/include/asm/io.h, and have '#include <asm-generic/io.h>' at the end of arch/xx/include/asm/io.h. For architecutres which has ARCH_HAS_IOREMAP_xx defining, we need move ''#include <asm-generic/iomap.h> dowe to below '#include <asm-generic/io.h>'. Please help check if it's still worth doing. ***move '#include <asm-generic/iomap.h>' below '#include <asm-generic/io.h>' *** diff --git a/arch/x86/include/asm/io.h b/arch/x86/include/asm/io.h index 8ab68cde1f13..a8d55fc62959 100644 --- a/arch/x86/include/asm/io.h +++ b/arch/x86/include/asm/io.h @@ -209,8 +209,6 @@ void memset_io(volatile void __iomem *, int, size_t); #define memcpy_toio memcpy_toio #define memset_io memset_io -#include <asm-generic/iomap.h> - /* * ISA space is 'always mapped' on a typical x86 system, no need to * explicitly ioremap() it. The fact that the ISA IO space is mapped @@ -329,6 +327,8 @@ extern bool is_early_ioremap_ptep(pte_t *ptep); #include <asm-generic/io.h> #undef PCI_IOBASE +#include <asm-generic/iomap.h> + #ifdef CONFIG_MTRR extern int __must_check arch_phys_wc_index(int handle); #define arch_phys_wc_index arch_phys_wc_index ***Building error after removing ARCH_HAS_IOREMAP_xx *** In file included from ./include/linux/io.h:13, from ./include/linux/irq.h:20, from ./include/xen/events.h:6, from arch/x86/entry/common.c:25: ./arch/x86/include/asm/io.h:321: warning: "ioremap_wc" redefined 321 | #define ioremap_wc ioremap_wc | In file included from ./arch/x86/include/asm/io.h:212: ./include/asm-generic/iomap.h:97: note: this is the location of the previous definition 97 | #define ioremap_wc ioremap | ./arch/x86/include/asm/io.h:323: warning: "ioremap_wt" redefined 323 | #define ioremap_wt ioremap_wt | ./include/asm-generic/iomap.h:101: note: this is the location of the previous definition 101 | #define ioremap_wt ioremap