Subject: Re: mmap() from kernel to user
To: Lennart Augustsson <email@example.com>
From: Kamal R. Prasad <firstname.lastname@example.org>
Date: 11/24/2004 00:29:57
Lennart Augustsson wrote:
> Kamal R. Prasad wrote:
>> Yes -I do want to use mmap(). Since driver and userland library are in
>> different address spaces, I do not know how to give userland ref to
>> the block of memory. The only way I am aware of is to give the
>> filename of the mmap()'ed file i.e. not using anon_map, but that would
>> mean using the filesystem -which I want to avoid.
> So it sounds like you do want to open the device and then mmap() it.
> There is no filesystem involved in that. Just the mmap() "method" for
> the device driver that gives the address for each mapped block.
> And then your driver has to make sure that the kernel buffer is kept
> up-to-date, probably by reading from the device as fast as possible.
> -- Lennart
Is there some src code using the mmap() "method" that does just that?