Re: [PATCH v5 4/5] arm64: introduce pfn_valid_region()

From: Ard Biesheuvel
Date: Mon Apr 02 2018 - 02:59:12 EST


On 2 April 2018 at 04:30, Jia He <hejianet@xxxxxxxxx> wrote:
> This is the preparation for further optimizing in early_pfn_valid
> on arm and arm64.
>

Same as before
- please share the code between ARM and arm64. if necessary, you can
invent a new HAVE_ARCH_xxx symbol that is only defined by ARM and
arm64
- please explain what the patch does and more importantly, why

> Signed-off-by: Jia He <jia.he@xxxxxxxxxxxxxxxx>
> ---
> arch/arm/include/asm/page.h | 3 ++-
> arch/arm/mm/init.c | 24 ++++++++++++++++++++++++
> arch/arm64/include/asm/page.h | 3 ++-
> arch/arm64/mm/init.c | 24 ++++++++++++++++++++++++
> 4 files changed, 52 insertions(+), 2 deletions(-)
>
> diff --git a/arch/arm/include/asm/page.h b/arch/arm/include/asm/page.h
> index f38909c..3bd810e 100644
> --- a/arch/arm/include/asm/page.h
> +++ b/arch/arm/include/asm/page.h
> @@ -158,9 +158,10 @@ typedef struct page *pgtable_t;
>
> #ifdef CONFIG_HAVE_ARCH_PFN_VALID
> extern int early_region_idx;
> -extern int pfn_valid(unsigned long);
> +extern int pfn_valid(unsigned long pfn);
> extern unsigned long memblock_next_valid_pfn(unsigned long pfn);
> #define skip_to_last_invalid_pfn(pfn) (memblock_next_valid_pfn(pfn) - 1)
> +extern int pfn_valid_region(unsigned long pfn);
> #endif
>
> #include <asm/memory.h>
> diff --git a/arch/arm/mm/init.c b/arch/arm/mm/init.c
> index 06ed190..bdcbf58 100644
> --- a/arch/arm/mm/init.c
> +++ b/arch/arm/mm/init.c
> @@ -201,6 +201,30 @@ int pfn_valid(unsigned long pfn)
> }
> EXPORT_SYMBOL(pfn_valid);
>
> +int pfn_valid_region(unsigned long pfn)
> +{
> + unsigned long start_pfn, end_pfn;
> + struct memblock_type *type = &memblock.memory;
> + struct memblock_region *regions = type->regions;
> +
> + if (early_region_idx != -1) {
> + start_pfn = PFN_DOWN(regions[early_region_idx].base);
> + end_pfn = PFN_DOWN(regions[early_region_idx].base +
> + regions[early_region_idx].size);
> +
> + if (pfn >= start_pfn && pfn < end_pfn)
> + return !memblock_is_nomap(
> + &regions[early_region_idx]);
> + }
> +
> + early_region_idx = memblock_search_pfn_regions(pfn);
> + if (early_region_idx == -1)
> + return false;
> +
> + return !memblock_is_nomap(&regions[early_region_idx]);
> +}
> +EXPORT_SYMBOL(pfn_valid_region);
> +
> /* HAVE_MEMBLOCK is always enabled on arm */
> unsigned long __init_memblock memblock_next_valid_pfn(unsigned long pfn)
> {
> diff --git a/arch/arm64/include/asm/page.h b/arch/arm64/include/asm/page.h
> index f0d8c8e5..7087b63 100644
> --- a/arch/arm64/include/asm/page.h
> +++ b/arch/arm64/include/asm/page.h
> @@ -39,9 +39,10 @@ typedef struct page *pgtable_t;
>
> #ifdef CONFIG_HAVE_ARCH_PFN_VALID
> extern int early_region_idx;
> -extern int pfn_valid(unsigned long);
> +extern int pfn_valid(unsigned long pfn);
> extern unsigned long memblock_next_valid_pfn(unsigned long pfn);
> #define skip_to_last_invalid_pfn(pfn) (memblock_next_valid_pfn(pfn) - 1)
> +extern int pfn_valid_region(unsigned long pfn);
> #endif
>
> #include <asm/memory.h>
> diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
> index 342e4e2..a1646b6 100644
> --- a/arch/arm64/mm/init.c
> +++ b/arch/arm64/mm/init.c
> @@ -293,6 +293,30 @@ int pfn_valid(unsigned long pfn)
> }
> EXPORT_SYMBOL(pfn_valid);
>
> +int pfn_valid_region(unsigned long pfn)
> +{
> + unsigned long start_pfn, end_pfn;
> + struct memblock_type *type = &memblock.memory;
> + struct memblock_region *regions = type->regions;
> +
> + if (early_region_idx != -1) {
> + start_pfn = PFN_DOWN(regions[early_region_idx].base);
> + end_pfn = PFN_DOWN(regions[early_region_idx].base +
> + regions[early_region_idx].size);
> +
> + if (pfn >= start_pfn && pfn < end_pfn)
> + return !memblock_is_nomap(
> + &regions[early_region_idx]);
> + }
> +
> + early_region_idx = memblock_search_pfn_regions(pfn);
> + if (early_region_idx == -1)
> + return false;
> +
> + return !memblock_is_nomap(&regions[early_region_idx]);
> +}
> +EXPORT_SYMBOL(pfn_valid_region);
> +
> /* HAVE_MEMBLOCK is always enabled on arm64 */
> unsigned long __init_memblock memblock_next_valid_pfn(unsigned long pfn)
> {
> --
> 2.7.4
>