Re: [PATCH 1/3] powerpc/64: __ioremap_at clean up in the error case

[Christophe Leroy <christophe.leroy@c-s.fr>]

Hi Nick,

Le 10/06/2019 à 05:08, Nicholas Piggin a écrit :
> __ioremap_at error handling is wonky, it requires caller to clean up
> after it. Implement a helper that does the map and error cleanup and
> remove the requirement from the caller.
> 
> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
> ---
> 
> This series is a different approach to the problem, using the generic
> ioremap_page_range directly which reduces added code, and moves
> the radix specific code into radix files. Thanks to Christophe for
> pointing out various problems with the previous patch.
> 
>   arch/powerpc/mm/pgtable_64.c | 27 ++++++++++++++++++++-------
>   1 file changed, 20 insertions(+), 7 deletions(-)
> 
> diff --git a/arch/powerpc/mm/pgtable_64.c b/arch/powerpc/mm/pgtable_64.c
> index d2d976ff8a0e..6bd3660388aa 100644
> --- a/arch/powerpc/mm/pgtable_64.c
> +++ b/arch/powerpc/mm/pgtable_64.c

[...]

> @@ -182,8 +197,6 @@ void __iomem * __ioremap_caller(phys_addr_t addr, unsigned long size,
>   
>   		area->phys_addr = paligned;
>   		ret = __ioremap_at(paligned, area->addr, size, prot);
> -		if (!ret)
> -			vunmap(area->addr);

AFAICS, ioremap_range() calls unmap_kernel_range() in the error case,
but I can't see that that function does the vunmap(), does it ?. If not, 
who frees the area allocated by __get_vm_area_caller() ?

Christophe