RE: [PATCH][2.6][2/5]Support for HPET based timer

["Pallipadi, Venkatesh" <venkatesh.pallipadi@intel.com>]

Yes. I hadn't thought about early_ioremap option. There seems to be
multiple ways of doing early ioremap: bt_ioremap() and boot_ioremap(). I
will look at them closer and work on changing HPET code to use one of
these in place of fixmap.

Thanks,
-Venkatesh  

> -----Original Message-----
> From: Mikael Pettersson [mailto:mikpe@csd.uu.se] 
> Sent: Wednesday, August 20, 2003 3:47 AM
> To: Andi Kleen
> Cc: Vojtech Pavlik; linux-kernel@vger.kernel.org; Pallipadi, Venkatesh
> Subject: Re: [PATCH][2.6][2/5]Support for HPET based timer
> 
> 
> Andi Kleen writes:
>  > Vojtech Pavlik <vojtech@suse.cz> writes:
>  > 
>  > > On Tue, Aug 19, 2003 at 05:18:50PM -0700, Pallipadi, 
> Venkatesh wrote:
>  > > 
>  > > > Fixmap is for HPET memory map address access. As the timer
>  > > > initialization happen 
>  > > > early in the boot sequence (before vm initialization), 
> we need to have
>  > > > fixmap() 
>  > > > and fix_to_virt() to access HPET memory map address.
>  > > 
>  > > Ahh, yes, you're right. You can't use ioremap at that 
> time. Actually I
>  > > did the same on x86_64 not only because of vsyscalls.
>  > 
>  > iirc i386 has an ioremap_early or somesuch.
> 
> bt_ioremap(). I wrote it to support early DMI scan so DMI data
> could be used to blacklist BIOSen that break local APICs.
> This was done pretty much just to handle Dell laptops.
>