Re: [PATCH 3/8] swiotlb: factor out a nr_slots helper

Christoph Hellwig
2021-02-05T09:45:22Z

On Thu, Feb 04, 2021 at 10:09:02PM +0000, Robin Murphy wrote:
>> diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
>> index 838dbad10ab916..0c0b81799edbdb 100644
>> --- a/kernel/dma/swiotlb.c
>> +++ b/kernel/dma/swiotlb.c
>> @@ -194,6 +194,11 @@ static inline unsigned long io_tlb_offset(unsigned long val)
>> return val & (IO_TLB_SEGSIZE - 1);
>> }
>> +static unsigned long nr_slots(u64 val)
>> +{
>> + return ALIGN(val, 1 << IO_TLB_SHIFT) >> IO_TLB_SHIFT;
>
> Would DIV_ROUND_UP(val, 1 << IOTLB_SHIFT) be even clearer?

Not sure it is all that much cleaner, but it does fit a common pattern,
so I'll switch to that.