[PATCH v2 23/29] ARM: kernel: refer to swapper_pg_dir via its symbol

[Nicolas Pitre]

On Sun, 3 Sep 2017, Ard Biesheuvel wrote:

> The location of swapper_pg_dir is relative to the kernel, not to
> PAGE_OFFSET or PHYS_OFFSET. So define the symbol relative to the
> start of the kernel image, and refer to it via its name.

Could it cause a section access mismatch if defined in the __HEAD 
section?

Otherwise

Acked-by: Nicolas Pitre <nico at linaro.org>

> 
> Cc: Russell King <linux at armlinux.org.uk>
> Signed-off-by: Ard Biesheuvel <ard.biesheuvel at linaro.org>
> ---
>  arch/arm/kernel/head.S | 13 ++++---------
>  1 file changed, 4 insertions(+), 9 deletions(-)
> 
> diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S
> index 5d685e86148c..71bc0d037bc9 100644
> --- a/arch/arm/kernel/head.S
> +++ b/arch/arm/kernel/head.S
> @@ -48,14 +48,6 @@
>  #define PMD_ORDER	2
>  #endif
>  
> -	.globl	swapper_pg_dir
> -	.equ	swapper_pg_dir, KERNEL_RAM_VADDR - PG_DIR_SIZE
> -
> -	.macro	pgtbl, rd, phys
> -	add	\rd, \phys, #TEXT_OFFSET
> -	sub	\rd, \rd, #PG_DIR_SIZE
> -	.endm
> -
>  /*
>   * Kernel startup entry point.
>   * ---------------------------
> @@ -77,6 +69,9 @@
>  	.arm
>  
>  	__HEAD
> +	.globl	swapper_pg_dir
> +	.equ	swapper_pg_dir, . - PG_DIR_SIZE
> +
>  ENTRY(stext)
>   ARM_BE8(setend	be )			@ ensure we are in BE8 mode
>  
> @@ -172,7 +167,7 @@ ENDPROC(stext)
>   *  r4 = physical page table address
>   */
>  __create_page_tables:
> -	pgtbl	r4, r8				@ page table address
> +	adr_l	r4, swapper_pg_dir		@ page table address
>  
>  	/*
>  	 * Clear the swapper page table
> -- 
> 2.11.0
> 
>