Re: [PATCH] [1/1] CPU-i386-Geode: Chipset access macros do not work as expected (2nd try)

[Andrew Morton <akpm@linux-foundation.org>]

On Mon, 30 Apr 2007 17:33:41 +0200
Juergen Beisert <juergen127@kreuzholzen.de> wrote:

> From: Juergen Beisert <juergen.beisert@weihenstephan.org>
> 
> Replace NSC/Cyrix specific chipset access macros by inlined functions.
> With the macros a line like this fails (and does nothing):
> 	setCx86(CX86_CCR2, getCx86(CX86_CCR2) | 0x88);
> With inlined functions this line will work as expected.
> 
> Note about a side effect: Seems on Geode GX1 based systems the
> "suspend on halt power saving feature" was never enabled due to this
> wrong macro expansion. With inlined functions it will be enabled, but
> this will stop the TSC when the CPU runs into a HLT instruction.
> Kernel outputs something like this:
> 	Clocksource tsc unstable (delta = -472746897 ns)
> Tested on a Geode GX1 system.
> 
> This is the second version with some modifications suggested by
> Mikael Pettersson
> 
> Signed-off-by: Juergen Beisert <juergen.beisert@weihenstephan.org>
> 
> Index: linux-2.6.21/include/asm-i386/processor.h
> ===================================================================
> --- linux-2.6.21.orig/include/asm-i386/processor.h
> +++ linux-2.6.21/include/asm-i386/processor.h
> @@ -202,37 +202,6 @@ static inline void clear_in_cr4 (unsigne
>  	write_cr4(cr4);
>  }
> 
> -/*
> - *      NSC/Cyrix CPU configuration register indexes
> - */
> -
> -#define CX86_PCR0 0x20
> -#define CX86_GCR  0xb8
> -#define CX86_CCR0 0xc0
> -#define CX86_CCR1 0xc1
> -#define CX86_CCR2 0xc2
> -#define CX86_CCR3 0xc3
> -#define CX86_CCR4 0xe8
> -#define CX86_CCR5 0xe9
> -#define CX86_CCR6 0xea
> -#define CX86_CCR7 0xeb
> -#define CX86_PCR1 0xf0
> -#define CX86_DIR0 0xfe
> -#define CX86_DIR1 0xff
> -#define CX86_ARR_BASE 0xc4
> -#define CX86_RCR_BASE 0xdc

This clashes with Andi's "msr-index" patch:

ftp://ftp.firstfloor.org/pub/ak/x86_64/quilt/patches/msr-index

Perhaps it'd be best to wait until msr-index goes upstream and to raise a
patch then.  Or to redo and retest against 2.6.21-rc7-mm2, which includes
msr-index.

Also, include/asm-x86_64/processor.h has a getCx86(), too.  Does it also
need fixing?