Re: [PATCH v6 04/11] powerpc/mce_power: Use functions to track lockless pgtbl walks

[Christophe Leroy <christophe.leroy@xxxxxx>]

Le 06/02/2020 à 04:08, Leonardo Bras a écrit :
> Applies the new functions used for tracking lockless pgtable walks on
> addr_to_pfn().
>
> local_irq_{save,restore} is already inside {begin,end}_lockless_pgtbl_walk,
> so there is no need to repeat it here.
>
> Signed-off-by: Leonardo Bras <leonardo@xxxxxxxxxxxxx>
> ---
>   arch/powerpc/kernel/mce_power.c | 6 +++---
>   1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/arch/powerpc/kernel/mce_power.c b/arch/powerpc/kernel/mce_power.c
> index 1cbf7f1a4e3d..a9e38ef4e437 100644
> --- a/arch/powerpc/kernel/mce_power.c
> +++ b/arch/powerpc/kernel/mce_power.c
> @@ -29,7 +29,7 @@ unsigned long addr_to_pfn(struct pt_regs *regs, unsigned long addr)
>   {
>   	pte_t *ptep;
>   	unsigned int shift;
> -	unsigned long pfn, flags;
> +	unsigned long pfn, irq_mask;

Why change the name ? flags is a well known historical name.

>   	struct mm_struct *mm;
>   
>   	if (user_mode(regs))
> @@ -37,7 +37,7 @@ unsigned long addr_to_pfn(struct pt_regs *regs, unsigned long addr)
>   	else
>   		mm = &init_mm;
>   
> -	local_irq_save(flags);
> +	irq_mask = begin_lockless_pgtbl_walk();
>   	ptep = __find_linux_pte(mm->pgd, addr, NULL, &shift);
>   
>   	if (!ptep || pte_special(*ptep)) {
> @@ -53,7 +53,7 @@ unsigned long addr_to_pfn(struct pt_regs *regs, unsigned long addr)
>   	}
>   
>   out:
> -	local_irq_restore(flags);
> +	end_lockless_pgtbl_walk(irq_mask);
>   	return pfn;
>   }
>   

Christophe