Messages in this thread | | | Date | Tue, 17 Oct 2006 15:29:34 +0800 | From | Qi Yong <> | Subject | Re: [RFC][PATCH 3/9] actual generic PAGE_SIZE infrastructure |
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Dave Hansen wrote:
>* Add _ALIGN_UP() which we'll use now and _ALIGN_DOWN(), just for > parity. >* Define ASM_CONST() macro to help using constants in both assembly > and C code. Several architectures have some form of this, and > they will be consolidated around this one. >* Actually create PAGE_SHIFT and PAGE_SIZE macros >* For now, require that architectures enable GENERIC_PAGE_SIZE in > order to get this new code. This option will be removed by the > last patch in the series, and makes the series bisect-safe. >* Note that this moves the compiler.h define outside of the > #ifdef __KERNEL__, but that's OK because it has its own. > >Signed-off-by: Dave Hansen <haveblue@us.ibm.com> >--- > > threadalloc-dave/include/asm-generic/page.h | 31 ++++++++++++++++++-- > threadalloc-dave/mm/Kconfig | 43 ++++++++++++++++++++++++++++ > 2 files changed, 71 insertions(+), 3 deletions(-) > >diff -puN include/asm-generic/page.h~generic-PAGE_SIZE-infrastructure include/asm-generic/page.h >--- threadalloc/include/asm-generic/page.h~generic-PAGE_SIZE-infrastructure 2006-08-30 15:15:00.000000000 -0700 >+++ threadalloc-dave/include/asm-generic/page.h 2006-08-30 15:15:01.000000000 -0700 >@@ -1,11 +1,36 @@ > #ifndef _ASM_GENERIC_PAGE_H > #define _ASM_GENERIC_PAGE_H > >+#include <linux/compiler.h> >+#include <linux/align.h> >+ > #ifdef __KERNEL__ >-#ifndef __ASSEMBLY__ > >-#include <linux/compiler.h> >+#ifdef __ASSEMBLY__ >+#define ASM_CONST(x) x >+#else >+#define __ASM_CONST(x) x##UL >+#define ASM_CONST(x) __ASM_CONST(x) >+#endif >+ >+#ifdef CONFIG_ARCH_GENERIC_PAGE_SIZE >+ >+#define PAGE_SHIFT CONFIG_PAGE_SHIFT >+#define PAGE_SIZE (ASM_CONST(1) << PAGE_SHIFT) > >
Your generic page.h hides PAGE_SIZE under "#ifdef __KERNEL__". That would cause severe userland compile failures.
Most archs have PAGE_SIZE visible to userland. Please keep PAGE_SIZE and its friends outside "#ifdef __KERNEL__".
-- qiyong
>+ >+/* >+ * Subtle: (1 << PAGE_SHIFT) is an int, not an unsigned long. So if we >+ * assign PAGE_MASK to a larger type it gets extended the way we want >+ * (i.e. with 1s in the high bits) >+ */ >+#define PAGE_MASK (~((1 << PAGE_SHIFT) - 1)) > >+/* to align the pointer to the (next) page boundary */ >+#define PAGE_ALIGN(addr) ALIGN(addr, PAGE_SIZE) >+ >+#endif /* CONFIG_ARCH_GENERIC_PAGE_SIZE */ >+ >+#ifndef __ASSEMBLY__ > #ifndef CONFIG_ARCH_HAVE_GET_ORDER > /* Pure 2^n version of get_order */ > static __inline__ __attribute_const__ int get_order(unsigned long size) >@@ -22,7 +47,7 @@ static __inline__ __attribute_const__ in > } > > #endif /* CONFIG_ARCH_HAVE_GET_ORDER */ >-#endif /* __ASSEMBLY__ */ >+#endif /* __ASSEMBLY__ */ > #endif /* __KERNEL__ */ > > #endif /* _ASM_GENERIC_PAGE_H */ > > -- Qi Yong
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