Re: [PATCH 3/3] xen/x86: Implement x86_apic_ops

[Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>]

On Tue, Mar 20, 2012 at 06:31:37PM -0700, Suresh Siddha wrote:
> On Tue, 2012-03-20 at 20:12 -0400, Konrad Rzeszutek Wilk wrote:
> > Or rather just implement one different function as opposed
> > to the native one : the read function.
> > 
> > We synthesize the values.
> > 
> > Suggested-by:  Suresh Siddha <suresh.b.siddha@intel.com>
> > Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
> > ---
> >  arch/x86/xen/Makefile    |    2 +-
> >  arch/x86/xen/apic.c      |   17 +++++++++++++++++
> >  arch/x86/xen/enlighten.c |    2 ++
> >  arch/x86/xen/xen-ops.h   |    4 ++++
> >  4 files changed, 24 insertions(+), 1 deletions(-)
> >  create mode 100644 arch/x86/xen/apic.c
> > 
> > diff --git a/arch/x86/xen/Makefile b/arch/x86/xen/Makefile
> > index add2c2d..96ab2c0 100644
> > --- a/arch/x86/xen/Makefile
> > +++ b/arch/x86/xen/Makefile
> > @@ -20,5 +20,5 @@ obj-$(CONFIG_EVENT_TRACING) += trace.o
> >  obj-$(CONFIG_SMP)		+= smp.o
> >  obj-$(CONFIG_PARAVIRT_SPINLOCKS)+= spinlock.o
> >  obj-$(CONFIG_XEN_DEBUG_FS)	+= debugfs.o
> > -obj-$(CONFIG_XEN_DOM0)		+= vga.o
> > +obj-$(CONFIG_XEN_DOM0)		+= apic.o vga.o
> >  obj-$(CONFIG_SWIOTLB_XEN)	+= pci-swiotlb-xen.o
> > diff --git a/arch/x86/xen/apic.c b/arch/x86/xen/apic.c
> > new file mode 100644
> > index 0000000..c53b3ef
> > --- /dev/null
> > +++ b/arch/x86/xen/apic.c
> > @@ -0,0 +1,17 @@
> > +#include <linux/init.h>
> > +#include <asm/x86_init.h>
> > +
> > +unsigned int xen_io_apic_read(unsigned apic, unsigned reg)
> > +{
> > +	if (reg == 0x1)
> > +		return 0x00170020;
> > +	else if (reg == 0x0)
> > +		return 0x00000000;
> 
> For IO-APIC ID register (0), you can probably use the argument 'apic' to
> set the ID bits in the returned register.

ok, that would be just
return 0x0000000 | apic

right? Since the last 8 bits are the apic value?
> 
> > +
> > +	return 0xfd;
> 
> 0xff might be better.

<nods> Done!