Re: [PATCH v3 4/5] arm64: introduce pfn_valid_region()

[Wei Yang]

On Sun, Mar 25, 2018 at 08:02:18PM -0700, Jia He wrote:
>This is the preparation for further optimizing in early_pfn_valid
>on arm64.
>
>Signed-off-by: Jia He <jia.he@xxxxxxxxxxxxxxxx>
>---
> arch/arm64/include/asm/page.h |  3 ++-
> arch/arm64/mm/init.c          | 25 ++++++++++++++++++++++++-
> 2 files changed, 26 insertions(+), 2 deletions(-)
>
>diff --git a/arch/arm64/include/asm/page.h b/arch/arm64/include/asm/page.h
>index 60d02c8..da2cba3 100644
>--- a/arch/arm64/include/asm/page.h
>+++ b/arch/arm64/include/asm/page.h
>@@ -38,7 +38,8 @@ extern void clear_page(void *to);
> typedef struct page *pgtable_t;
> 
> #ifdef CONFIG_HAVE_ARCH_PFN_VALID
>-extern int pfn_valid(unsigned long);
>+extern int pfn_valid(unsigned long pfn);
>+extern int pfn_valid_region(unsigned long pfn, int *last_idx);
> #endif
> 
> #include <asm/memory.h>
>diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
>index 00e7b90..06433d5 100644
>--- a/arch/arm64/mm/init.c
>+++ b/arch/arm64/mm/init.c
>@@ -290,7 +290,30 @@ int pfn_valid(unsigned long pfn)
> 	return memblock_is_map_memory(pfn << PAGE_SHIFT);
> }
> EXPORT_SYMBOL(pfn_valid);
>-#endif
>+
>+int pfn_valid_region(unsigned long pfn, int *last_idx)
>+{
>+	unsigned long start_pfn, end_pfn;
>+	struct memblock_type *type = &memblock.memory;
>+
>+	if (*last_idx != -1) {
>+		start_pfn = PFN_DOWN(type->regions[*last_idx].base);

PFN_UP() should be used.

>+		end_pfn= PFN_DOWN(type->regions[*last_idx].base +
>+					type->regions[*last_idx].size);
>+
>+		if (pfn >= start_pfn && pfn < end_pfn)
>+			return !memblock_is_nomap(
>+				&memblock.memory.regions[*last_idx]);

Could use type->regions directly.

>+	}
>+
>+	*last_idx = memblock_search_pfn_regions(pfn);
>+	if (*last_idx == -1)
>+		return false;
>+
>+	return !memblock_is_nomap(&memblock.memory.regions[*last_idx]);

Could use type->regions directly.

Well, since your check memblock.memory.regions, how about use a variable
equals memblock.memory.regions directly instead of type->regions?

For example:

struct memblock_region *regions = memblock.memory.regions;

>+}
>+EXPORT_SYMBOL(pfn_valid_region);
>+#endif /*CONFIG_HAVE_ARCH_PFN_VALID*/
> 
> #ifndef CONFIG_SPARSEMEM
> static void __init arm64_memory_present(void)
>-- 
>2.7.4

-- 
Wei Yang
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