Blackfin arch: add supporting for double fault debug handling

Signed-off-by: Robin Getz <rgetz@blackfin.uclinux.org>
Signed-off-by: Mike Frysinger <vapier.adi@gmail.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>

1 files changed, 37 insertions, 3 deletions

diff --git a/arch/blackfin/mach-common/head.S b/arch/blackfin/mach-common/head.S
index 191b4e974c4..7cb21cfcbf2 100644
--- a/arch/blackfin/mach-common/head.S
+++ b/arch/blackfin/mach-common/head.S
@@ -90,12 +90,46 @@ ENTRY(__start)
         [p0] = R0;
         SSYNC;
 
-        /* Save RETX, in case of doublefault */
-        p0.l = ___retx;
-        p0.h = ___retx;
+        /* in case of double faults, save a few things */
+        p0.l = _init_retx;
+        p0.h = _init_retx;
         R0 = RETX;
         [P0] = R0;
 
+#ifdef CONFIG_DEBUG_DOUBLEFAULT
+        /* Only save these if we are storing them,
+         * This happens here, since L1 gets clobbered
+         * below
+         */
+        p0.l = _saved_retx;
+        p0.h = _saved_retx;
+        p1.l = _init_saved_retx;
+        p1.h = _init_saved_retx;
+        r0 = [p0];
+        [p1] = r0;
+
+        p0.l = _saved_dcplb_fault_addr;
+        p0.h = _saved_dcplb_fault_addr;
+        p1.l = _init_saved_dcplb_fault_addr;
+        p1.h = _init_saved_dcplb_fault_addr;
+        r0 = [p0];
+        [p1] = r0;
+
+        p0.l = _saved_icplb_fault_addr;
+        p0.h = _saved_icplb_fault_addr;
+        p1.l = _init_saved_icplb_fault_addr;
+        p1.h = _init_saved_icplb_fault_addr;
+        r0 = [p0];
+        [p1] = r0;
+
+        p0.l = _saved_seqstat;
+        p0.h = _saved_seqstat;
+        p1.l = _init_saved_seqstat;
+        p1.h = _init_saved_seqstat;
+        r0 = [p0];
+        [p1] = r0;
+#endif
+
         /* Initialize stack pointer */
         sp.l = lo(INITIAL_STACK);
         sp.h = hi(INITIAL_STACK);