Re: [PATCH v2 3/4] ARM: nommu: display vectors base

From: Russell King - ARM Linux
Date: Mon Jan 30 2017 - 09:12:02 EST


On Sun, Jan 22, 2017 at 08:52:12AM +0530, afzal mohammed wrote:
> The exception base address is now dynamically estimated for no-MMU,
> display it. As it is the case, now limit VECTORS_BASE usage to MMU
> scenario.
>
> Signed-off-by: afzal mohammed <afzal.mohd.ma@xxxxxxxxx>

As I wrote elsewhere...

> diff --git a/arch/arm/include/asm/memory.h b/arch/arm/include/asm/memory.h
> index 0b5416fe7709..9ae474bf84fc 100644
> --- a/arch/arm/include/asm/memory.h
> +++ b/arch/arm/include/asm/memory.h
> @@ -83,6 +83,8 @@
> #define IOREMAP_MAX_ORDER 24
> #endif
>
> +#define VECTORS_BASE UL(0xffff0000)
> +
> #else /* CONFIG_MMU */
>
> /*
> @@ -111,8 +113,6 @@
>
> #endif /* !CONFIG_MMU */
>
> -#define VECTORS_BASE UL(0xffff0000)

I think adding a definition for VECTORS_BASE in asm/memory.h for nommu:

extern unsigned long vectors_base;
#define VECTORS_BASE vectors_base

> diff --git a/arch/arm/mm/init.c b/arch/arm/mm/init.c
> index 823e119a5daa..9c68e3aba87c 100644
> --- a/arch/arm/mm/init.c
> +++ b/arch/arm/mm/init.c
> @@ -522,7 +522,12 @@ void __init mem_init(void)
> " .data : 0x%p" " - 0x%p" " (%4td kB)\n"
> " .bss : 0x%p" " - 0x%p" " (%4td kB)\n",
>
> +#ifdef CONFIG_MMU
> MLK(VECTORS_BASE, VECTORS_BASE + PAGE_SIZE),
> +#else
> + MLK(vectors_base, vectors_base + PAGE_SIZE),
> +#endif

will mean that this conditional becomes unnecessary.

> diff --git a/arch/arm/mm/mm.h b/arch/arm/mm/mm.h
> index ce727d47275c..546f09437fca 100644
> --- a/arch/arm/mm/mm.h
> +++ b/arch/arm/mm/mm.h
> @@ -79,8 +79,9 @@ struct static_vm {
> extern struct list_head static_vmlist;
> extern struct static_vm *find_static_vm_vaddr(void *vaddr);
> extern __init void add_static_vm_early(struct static_vm *svm);
> -
> -#endif
> +#else /* CONFIG_MMU */
> +extern unsigned long vectors_base;
> +#endif /* CONFIG_MMU */

and you don't need this here either.

Thanks.

--
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