hi mulyadi

2012/4/6 Mulyadi Santosa [off-list ref]:

Hi...

On Fri, Apr 6, 2012 at 09:19, loody [off-list ref] wrote:

quoted

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.

quoted

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