lkml.org 
[lkml]   [2019]   [Feb]   [18]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
SubjectRe: [PATCH 01/13] arm64: mm: Add p?d_large() definitions
Date
On Fri, Feb 15, 2019 at 05:02:22PM +0000, Steven Price wrote:
> From: James Morse <james.morse@arm.com>
>
> Exposing the pud/pgd levels of the page tables to walk_page_range() means
> we may come across the exotic large mappings that come with large areas
> of contiguous memory (such as the kernel's linear map).
>
> Expose p?d_large() from each architecture to detect these large mappings.
>
> arm64 already has these macros defined, but with a different name.
> p?d_large() is used by s390, sparc and x86. Only arm/arm64 use p?d_sect().
> Add a macro to allow both names.
>
> By not providing a pgd_large(), we get the generic version that always
> returns 0.

This last sentence isn't true until a subsequent patch, so it's probably
worth dropping it to avoid confusion.

Thanks,
Mark.

>
> Signed-off-by: James Morse <james.morse@arm.com>
> Signed-off-by: Steven Price <steven.price@arm.com>
> ---
> arch/arm64/include/asm/pgtable.h | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
> index de70c1eabf33..09d308921625 100644
> --- a/arch/arm64/include/asm/pgtable.h
> +++ b/arch/arm64/include/asm/pgtable.h
> @@ -428,6 +428,7 @@ extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
> PMD_TYPE_TABLE)
> #define pmd_sect(pmd)((pmd_val(pmd) & PMD_TYPE_MASK) == \
> PMD_TYPE_SECT)
> +#define pmd_large(x)pmd_sect(x)
>
> #if defined(CONFIG_ARM64_64K_PAGES) || CONFIG_PGTABLE_LEVELS < 3
> #define pud_sect(pud)(0)
> @@ -435,6 +436,7 @@ extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
> #else
> #define pud_sect(pud)((pud_val(pud) & PUD_TYPE_MASK) == \
> PUD_TYPE_SECT)
> +#define pud_large(x)pud_sect(x)
> #define pud_table(pud)((pud_val(pud) & PUD_TYPE_MASK) == \
> PUD_TYPE_TABLE)
> #endif
> --
> 2.20.1
>
IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.

\
 
 \ /
  Last update: 2019-02-18 12:16    [W:0.108 / U:28.144 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site