On Fri, 30 Aug 2002, Balaji, Pavan wrote:
>
> I'm a little bit confused about this vmapbuf() thing. This is what I think,
> correct me if I'm wrong.
>
> I have this User Virtual address, userbuf --> associated to physadd
>
> Now, I do vmapbuf(physadd), and I get a Kernel Virtual Address associated to
> this "physadd". Now, I write to this Kernel Virtual Address and it reflects
> in userbuf? OhmyGod!!! Is that what it's supposed to do? Hope it doesn't
> oops my machine..
no that is correct. this function is for making user space buffers map
into kernel space..
you just want the second half of this..
Now I have a question for you....
how do you know what pages you want to map into kernel virtual space?
>
> Also, if this is right, how do I get the kernel virtual address it's
> associated to? The function returns a void.
The buf steucture is updated to hold KV addresses for the region.
'bp' is a pointer to a complicated struct that defines the buffer, not
to the address of the buffer itself.
>
> Thanx.
>
> Pavan Balaji,
> Intel Corporation
> Email: [EMAIL PROTECTED]
>
> "Only the Paranoid Survive" -- Andy Grove
>
>
> > -----Original Message-----
> > From: Julian Elischer [mailto:[EMAIL PROTECTED]]
> > Sent: Friday, August 30, 2002 3:20 PM
> > To: Balaji, Pavan
> > Cc: '[EMAIL PROTECTED]'
> > Subject: Re: Copying from Virtual Address Space to Physical Address
> >
> >
> >
> >
> > On Fri, 30 Aug 2002, Julian Elischer wrote:
> >
> > > Physio() does this.. first it finds the physical addresses
> > of the user
> > > pages targetted, then it maps those pages into kernel
> > space, and then it
> > > initiates IO to them. (this actually needs to change but
> > for now it's
> > > true.
> >
> >
> > to correct myself..
> > physio() calls vmapbuf(bp) in order to do it..
> >
> >
>
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