powerpc: Rework set_dabr so it can take a DABRX value as well

Rework set_dabr to take a DABRX value as well.

Both the pseries and PS3 hypervisors do some checks on the DABRX
values that are passed in the hcall.  This patch stops bogus values
from being passed to hypervisor.  Also, in the case where we are
clearing the breakpoint, where DABR and DABRX are zero, we modify the
DABRX value to make it valid so that the hcall won't fail.

Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h
index ad400a5..121a90b 100644
--- a/arch/powerpc/include/asm/reg.h
+++ b/arch/powerpc/include/asm/reg.h
@@ -208,6 +208,9 @@
 #define SPRN_DABRX	0x3F7	/* Data Address Breakpoint Register Extension */
 #define   DABRX_USER	(1UL << 0)
 #define   DABRX_KERNEL	(1UL << 1)
+#define   DABRX_HYP	(1UL << 2)
+#define   DABRX_BTI	(1UL << 3)
+#define   DABRX_ALL     (DABRX_BTI | DABRX_HYP | DABRX_KERNEL | DABRX_USER)
 #define SPRN_DAR	0x013	/* Data Address Register */
 #define SPRN_DBCR	0x136	/* e300 Data Breakpoint Control Reg */
 #define SPRN_DSISR	0x012	/* Data Storage Interrupt Status Register */