Re: [PATCH 4/5] SCSI: add cpu cache flushes after kmapping and modifying a page

[Tejun Heo <htejun@gmail.com>]

Christoph Hellwig wrote:
> On Sun, Jun 04, 2006 at 12:41:20PM +0900, Tejun Heo wrote:
>>  			local_irq_save(flags);
>>  			buf = kmap_atomic(sg->page, KM_IRQ0) + sg->offset;
>>  			memcpy(buf, tw_dev->generic_buffer_virt[request_id], sg->length);
>> +			flush_kernel_dcache_page(kmap_atomic_to_page(buf - sg->offset));
>>  			kunmap_atomic(buf - sg->offset, KM_IRQ0);
>>  			local_irq_restore(flags);
> 
> all these should switch to scsi_kmap_atomic_sg which should do the
> flush_kernel_dcache_page call for you.
> 

This is not specific to scsi or block.  This is a common problem for all 
kmap users.  As I wrote in the other mail, I think this should be 
mandated at the kmap/kunmap() interface.

-- 
tejun