Messages in this thread |  | | From | Andrea Righi <> | Subject | Re: [PATCH -mm] PAGE_ALIGN(): correctly handle 64-bit values on 32-bit architectures (v2) | Date | Mon, 16 Jun 2008 10:35:37 +0200 (MEST) |
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Paul Mackerras wrote: > Andrea Righi writes: > >> Also move the PAGE_ALIGN() definitions out of include/asm-*/page.h in >> include/linux/mm.h. > > I'd rather see it in some other place than this, because > include/linux/mm.h is a large header that includes quite a lot of > other stuff. What's wrong with leaving it in each arch's page.h and > only changing it on those archs that have both 32-bit and 64-bit > variants? Or perhaps there is some other, lower-level header in > include/linux where it could go?
I think the only evident advantage of this is to have a single implementation, instead of dealing with (potentially) N different implementations.
Maybe a different place could be linux/mm_types.h, it's not so small, but at least it's smaller than linux/mm.h. However, it's a bit ugly to put a "function" in a file called mm_types.h.
Anyway, I've to say that fixing PAGE_ALIGN and leaving it in each page.h for now would be surely a simpler solution and would introduce less potential errors.
> >> diff --git a/arch/powerpc/boot/of.c b/arch/powerpc/boot/of.c >> index 61d9899..6bc72b1 100644 >> --- a/arch/powerpc/boot/of.c >> +++ b/arch/powerpc/boot/of.c >> @@ -8,6 +8,7 @@ >> */ >> #include <stdarg.h> >> #include <stddef.h> >> +#include <linux/mm.h> >> #include "types.h" >> #include "elf.h" >> #include "string.h" >> diff --git a/arch/powerpc/boot/page.h b/arch/powerpc/boot/page.h >> index 14eca30..aa42298 100644 >> --- a/arch/powerpc/boot/page.h >> +++ b/arch/powerpc/boot/page.h >> @@ -28,7 +28,4 @@ >> /* align addr on a size boundary - adjust address up if needed */ >> #define _ALIGN(addr,size) _ALIGN_UP(addr,size) >> >> -/* to align the pointer to the (next) page boundary */ >> -#define PAGE_ALIGN(addr) _ALIGN(addr, PAGE_SIZE) >> - >> #endif /* _PPC_BOOT_PAGE_H */ > > These parts are NAKed, because arch/powerpc/boot is a separate program > that doesn't use the kernel include files.
OK, so we also shouldn't use the linux/kernel.h's ALIGN() here, but leave the local _ALIGN() definition, right?
> >> diff --git a/include/asm-powerpc/page.h b/include/asm-powerpc/page.h >> index cffdf0e..e088545 100644 >> --- a/include/asm-powerpc/page.h >> +++ b/include/asm-powerpc/page.h >> @@ -119,9 +119,6 @@ extern phys_addr_t kernstart_addr; >> /* align addr on a size boundary - adjust address up if needed */ >> #define _ALIGN(addr,size) _ALIGN_UP(addr,size) >> >> -/* to align the pointer to the (next) page boundary */ >> -#define PAGE_ALIGN(addr) _ALIGN(addr, PAGE_SIZE) >> - >> /* >> * Don't compare things with KERNELBASE or PAGE_OFFSET to test for >> * "kernelness", use is_kernel_addr() - it should do what you want. > > We had already come across this issue on powerpc, and we fixed it by > making sure that the type of PAGE_MASK was int, not unsigned int. > However, I have no objection to using the ALIGN() macro from > include/linux/kernel.h instead.
Thanks, -Andrea
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