[PATCH 07/10] powerpc/64e/interrupt: handle bad_page_fault in C

[Christophe Leroy]

Le 15/03/2021 à 04:17, Nicholas Piggin a écrit :
> With non-volatile registers saved on interrupt, bad_page_fault
> can now be called by do_page_fault.
> 
> Signed-off-by: Nicholas Piggin <npiggin at gmail.com>
> ---
>   arch/powerpc/kernel/exceptions-64e.S | 6 ------
>   arch/powerpc/mm/fault.c              | 5 +----
>   2 files changed, 1 insertion(+), 10 deletions(-)
> 
> diff --git a/arch/powerpc/kernel/exceptions-64e.S b/arch/powerpc/kernel/exceptions-64e.S
> index a059ab3542c2..b08c84e0fa56 100644
> --- a/arch/powerpc/kernel/exceptions-64e.S
> +++ b/arch/powerpc/kernel/exceptions-64e.S
> @@ -937,12 +937,6 @@ storage_fault_common:
>   	ld	r14,PACA_EXGEN+EX_R14(r13)
>   	ld	r15,PACA_EXGEN+EX_R15(r13)
>   	bl	do_page_fault
> -	cmpdi	r3,0
> -	bne-	1f
> -	b	interrupt_return
> -	mr	r4,r3
> -	addi	r3,r1,STACK_FRAME_OVERHEAD
> -	bl	__bad_page_fault

Then __bad_page_fault() can be static now.

>   	b	interrupt_return
>   
>   /*
> diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c
> index 2e54bac99a22..44833660b21d 100644
> --- a/arch/powerpc/mm/fault.c
> +++ b/arch/powerpc/mm/fault.c
> @@ -552,12 +552,9 @@ static long __do_page_fault(struct pt_regs *regs)
>   	if (likely(entry)) {
>   		instruction_pointer_set(regs, extable_fixup(entry));
>   		return 0;
> -	} else if (!IS_ENABLED(CONFIG_PPC_BOOK3E_64)) {
> +	} else {
>   		__bad_page_fault(regs, err);
>   		return 0;
> -	} else {
> -		/* 32 and 64e handle the bad page fault in asm */
> -		return err;
>   	}
>   }
>   NOKPROBE_SYMBOL(__do_page_fault);
>