[RFC Patch 6/6] Adapt kexec and samples code to recognise PPC64 hardware breakpoint usage

[Geert Uytterhoeven]

On Fri, 15 May 2009, Michael Ellerman wrote:
> On Thu, 2009-05-14 at 15:59 +0200, Geert Uytterhoeven wrote:
> > On Thu, 14 May 2009, K.Prasad wrote:
> > > Modify kexec code to disable DABR registers before a reboot. Adapt the samples
> > > code to populate PPC64-arch specific fields.
> > > 
> > > Signed-off-by: K.Prasad <prasad at linux.vnet.ibm.com>
> > > ---
> > >  arch/powerpc/kernel/machine_kexec_64.c   |    6 
> > >  samples/hw_breakpoint/data_breakpoint.c  |    4 
> > > 
> > > Index: linux-2.6-tip.hbkpt/arch/powerpc/kernel/machine_kexec_64.c
> > > ===================================================================
> > > --- linux-2.6-tip.hbkpt.orig/arch/powerpc/kernel/machine_kexec_64.c	2009-05-14 00:17:24.000000000 +0530
> > > +++ linux-2.6-tip.hbkpt/arch/powerpc/kernel/machine_kexec_64.c	2009-05-14 09:48:09.000000000 +0530
> > > @@ -24,6 +24,7 @@
> > >  #include <asm/sections.h>	/* _end */
> > >  #include <asm/prom.h>
> > >  #include <asm/smp.h>
> > > +#include <asm/hw_breakpoint.h>
> > >  
> > >  int default_machine_kexec_prepare(struct kimage *image)
> > >  {
> > > @@ -214,6 +215,9 @@
> > >  	put_cpu();
> > >  
> > >  	local_irq_disable();
> > > +#ifdef CONFIG_PPC64
> >    ^^^^^^^^^^^^^^^^^^^
> > > +	hw_breakpoint_disable();
> > > +#endif
> >    ^^^^^^
> > 
> > What about providing a dummy definition of hw_breakpoint_disable()
> > in <asm/hw_breakpoint.h> if !CONFIG_PPC64?
> 
> That would be good.
> 
> What would be better, is to notice that machine_kexec_64.c is only ever
> built for 64-bit - hence the name. And so no ifdefs or anything else is
> required.

Right ;-)

But that can't be said for other files, like e.g. arch/powerpc/kernel/ptrace.c.

With kind regards,

Geert Uytterhoeven
Software Architect
Techsoft Centre

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