hi mulyadi 2012/4/6 Mulyadi Santosa <mulyadi.santosa@gmail.com>:
Hi...
On Fri, Apr 6, 2012 at 09:19, loody <miloody@gmail.com> wrote:
hi all: I am trying to write a driver for my block device which dma support high memory copying. I have register my device as "blk_bounce_any". But my driver cannot see block layer pass high memory to me so far.
perhaps because you need to kmap them first? If I remember correctly, Kmap is used for mapping high memory into kernel virtual memory. Isn't that the job for block layer?
I thought once I declare my block device as "blk_bounce_any", the block layer will pass the physical address of high memory to device.
BTW, is it 32 bit or 64 bit Linux kernel?
32-bits linux kernel.
Is there any user/kernel test program which will purposely send high memory for driver to use? or is there any flag when opening a file in user mode that will use high memory?
I recheck mmap and mmap manual page and I found none of such flag
does that mean mmap can specify which memory to map? if that is true, which range I should use?
-- regards,
Mulyadi Santosa Freelance Linux trainer and consultant
blog: the-hydra.blogspot.com training: mulyaditraining.blogspot.com
Appreciate your help