Static mappings at boottime

Russell King - ARM Linux linux at arm.linux.org.uk
Sat Jan 30 10:39:21 EST 2010


On Sun, Jan 31, 2010 at 12:13:42AM +0900, Khushhua Mogambo wrote:
> On Sat, Jan 30, 2010 at 11:55 PM, Russell King - ARM Linux
> <linux at arm.linux.org.uk> wrote:
> > On Sat, Jan 30, 2010 at 11:47:36PM +0900, Khushhua Mogambo wrote:
> >> And pass already mapped Virtual addr(and not phys addr) to device drivers
> >>  via IORESOURCE_MEM.
> >
> > But you can't do this.  Resources take physical addresses, not virtual
> > addresses.
>  but phys addr and virt addr is both u32 numbers
>  how can kernel detect i passes virt and not phys address?

No, virtual addresses are _pointers_, not integers.

> 
> >> i thinks that way i can do most use of virtual address space for ioremap
> >> and I can set VMALLOC size to maximum possible. also drivers doesnt have
> >> to worry about mapping(and no addr space is mapped twice in two code pieces)
> >>
> >> is it considered good kernel porting practice? can we face any problem
> >> after some times?
> >
> > Definitely not.
> sorry i asks two opposite qeustions same time.
> i am hopeful "Definitely not" is reply of second question ^^

It was in reply to the first question.



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