Messages in this thread | | | Subject | Re: [PATCH 2/2] arm64/mm: Use CONT_SHIFT to define CONT_PTE_SHIFT | From | Gavin Shan <> | Date | Thu, 10 Sep 2020 18:31:38 +1000 |
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Hi Anshuman,
On 9/10/20 4:17 PM, Anshuman Khandual wrote: > On 09/08/2020 12:49 PM, Gavin Shan wrote: >> The macro CONT_PTE_SHIFT actually depends on CONT_SHIFT, which has >> been defined in page-def.h, based on CONFIG_ARM64_CONT_SHIFT. Lets >> reflect the dependency. >> >> Signed-off-by: Gavin Shan <gshan@redhat.com> >> --- >> arch/arm64/include/asm/pgtable-hwdef.h | 4 +--- >> 1 file changed, 1 insertion(+), 3 deletions(-) >> >> diff --git a/arch/arm64/include/asm/pgtable-hwdef.h b/arch/arm64/include/asm/pgtable-hwdef.h >> index 8a399e666837..0bd9469f4323 100644 >> --- a/arch/arm64/include/asm/pgtable-hwdef.h >> +++ b/arch/arm64/include/asm/pgtable-hwdef.h >> @@ -81,14 +81,12 @@ >> /* >> * Contiguous page definitions. >> */ >> +#define CONT_PTE_SHIFT (CONT_SHIFT + PAGE_SHIFT) >> #ifdef CONFIG_ARM64_64K_PAGES >> -#define CONT_PTE_SHIFT (5 + PAGE_SHIFT) >> #define CONT_PMD_SHIFT (5 + PMD_SHIFT) >> #elif defined(CONFIG_ARM64_16K_PAGES) >> -#define CONT_PTE_SHIFT (7 + PAGE_SHIFT) >> #define CONT_PMD_SHIFT (5 + PMD_SHIFT) >> #else >> -#define CONT_PTE_SHIFT (4 + PAGE_SHIFT) >> #define CONT_PMD_SHIFT (4 + PMD_SHIFT) >> #endif > Could not a similar CONT_PMD be created from a new CONFIG_ARM64_CONT_PMD > config option, which would help unify CONT_PMD_SHIFT here as well ? >
I was thinking of it, to have CONFIG_ARM64_CONT_PMD and defined the following macros in arch/arm64/include/asm/page-def.h:
#define CONT_PMD_SHIFT CONFIG_ARM64_CONT_PMD_SHIFT #define CONT_PMD_SIZE (_AC(1, UL) << (CONT_PMD_SHIFT + PMD_SHIFT) #define CONT_PMD_MASK (~(CONT_PMD_SIZE - 1))
PMD_SHIFT is variable because PMD could be folded into PUD or PGD, depending on the kernel configuration. PMD_SHIFT is declared in arch/arm64/include/asm/pgtable-types.h, which isn't supposed to be included in "page-def.h".
So the peroper way to handle this might be drop the continuous page macros in page-def.h and introduce the following ones into pgtable-hwdef.h. I will post v2 to do this if it sounds good to you.
#define CONT_PTE_SHIFT (CONFIG_ARM64_CONT_PTE_SHIFT + PAGE_SHIFT) #define CONT_PMD_SHIFT (CONFIG_ARM64_CONT_PMD_SHIFT + PMD_SHIFT)
Thanks, Gavin
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