lkml.org 
[lkml]   [2018]   [Sep]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    SubjectRe: [RESEND PATCH v4 1/6] arm64/mm: Introduce the init_pg_dir.
    From
    Date
    Hi Jun,

    On 22/08/18 10:54, Jun Yao wrote:
    > To make the swapper_pg_dir read only, we will move it to the rodata
    > section. And force the kernel to set up the initial page table in
    > the init_pg_dir. After generating all levels page table, we copy
    > only the top level into the swapper_pg_dir during paging_init().

    Could you add v3's
    | Add init_pg_dir to vmlinux.lds.S and boiler-plate
    | clearing/cleaning/invalidating it in head.S.

    too. This makes it obvious that 'init_pg_dir isn't used yet' is deliberate.

    Reviewed-by: James Morse <james.morse@arm.com>


    Some boring nits:

    > diff --git a/arch/arm64/include/asm/assembler.h b/arch/arm64/include/asm/assembler.h
    > index 0bcc98dbba56..eb363a915c0e 100644
    > --- a/arch/arm64/include/asm/assembler.h
    > +++ b/arch/arm64/include/asm/assembler.h
    > @@ -456,6 +456,35 @@ USER(\label, ic ivau, \tmp2) // invalidate I line PoU

    > +/*
    > + * clear_pages - clear contiguous pages
    > + *
    > + * start, end: page aligend virtual addresses

    (Nit: aligned)


    > + */
    > + .macro clear_pages, start:req, end:req

    > diff --git a/arch/arm64/kernel/vmlinux.lds.S b/arch/arm64/kernel/vmlinux.lds.S
    > index 605d1b60469c..61d7cee3eaa6 100644
    > --- a/arch/arm64/kernel/vmlinux.lds.S
    > +++ b/arch/arm64/kernel/vmlinux.lds.S
    > @@ -68,6 +68,12 @@ jiffies = jiffies_64;
    > #define TRAMP_TEXT
    > #endif
    >
    > +#define INIT_PG_TABLES \

    ^ These are tabs ...

    > + . = ALIGN(PAGE_SIZE); \

    ^ ... but these are spaces.

    > + init_pg_dir = .; \
    > + . += SWAPPER_DIR_SIZE; \
    > + init_pg_end = .;

    Please pick one and stick with it. The macro above,
    CONFIG_UNMAP_KERNEL_AT_EL0, uses tabs, please do the same.



    Thanks,

    James

    \
     
     \ /
      Last update: 2018-09-07 11:57    [W:4.197 / U:0.432 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site