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

[Nicholas Piggin <npiggin@gmail.com>]

Christophe Leroy's on August 20, 2019 5:44 pm:
> 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() ?

Oh good catch, I guess we need to keep a free_vm_area here.

Thanks,
Nick