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>

5 files changed, 8 insertions, 3 deletions

diff --git a/arch/powerpc/include/asm/debug.h b/arch/powerpc/include/asm/debug.h
index 716d2f089eb..32de2577bb6 100644
--- a/arch/powerpc/include/asm/debug.h
+++ b/arch/powerpc/include/asm/debug.h
@@ -44,7 +44,7 @@ static inline int debugger_dabr_match(struct pt_regs *regs) { return 0; }
 static inline int debugger_fault_handler(struct pt_regs *regs) { return 0; }
 #endif
 
-extern int set_dabr(unsigned long dabr);
+extern int set_dabr(unsigned long dabr, unsigned long dabrx);
 #ifdef CONFIG_PPC_ADV_DEBUG_REGS
 extern void do_send_trap(struct pt_regs *regs, unsigned long address,
                          unsigned long error_code, int signal_code, int brkpt);
diff --git a/arch/powerpc/include/asm/hw_breakpoint.h b/arch/powerpc/include/asm/hw_breakpoint.h
index 39b323e80c3..c6f48eb5299 100644
--- a/arch/powerpc/include/asm/hw_breakpoint.h
+++ b/arch/powerpc/include/asm/hw_breakpoint.h
@@ -61,7 +61,7 @@ extern void ptrace_triggered(struct perf_event *bp,
                         struct perf_sample_data *data, struct pt_regs *regs);
 static inline void hw_breakpoint_disable(void)
 {
-        set_dabr(0);
+        set_dabr(0, 0);
 }
 extern void thread_change_pc(struct task_struct *tsk, struct pt_regs *regs);
 
diff --git a/arch/powerpc/include/asm/machdep.h b/arch/powerpc/include/asm/machdep.h
index 42ce570812c..236b4779ec4 100644
--- a/arch/powerpc/include/asm/machdep.h
+++ b/arch/powerpc/include/asm/machdep.h
@@ -180,7 +180,8 @@ struct machdep_calls {
         void            (*enable_pmcs)(void);
 
         /* Set DABR for this platform, leave empty for default implemenation */
-        int             (*set_dabr)(unsigned long dabr);
+        int             (*set_dabr)(unsigned long dabr,
+                                    unsigned long dabrx);
 
 #ifdef CONFIG_PPC32     /* XXX for now */
         /* A general init function, called by ppc_init in init/main.c.
diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h
index 7e7fa13e466..83efc6e8154 100644
--- a/arch/powerpc/include/asm/processor.h
+++ b/arch/powerpc/include/asm/processor.h
@@ -219,6 +219,7 @@ struct thread_struct {
 #endif /* CONFIG_HAVE_HW_BREAKPOINT */
 #endif
         unsigned long   dabr;           /* Data address breakpoint register */
+        unsigned long   dabrx;          /*      ... extension  */
         unsigned long   trap_nr;        /* last trap # on this thread */
 #ifdef CONFIG_ALTIVEC
         /* Complete AltiVec register set */
diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h
index ad400a535d2..121a90bbf77 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 */