sparc: Add kgdb support.

Current limitations:

1) On SMP single stepping has some fundamental issues,
   shared with other sw single-step architectures such
   as mips and arm.

2) On 32-bit sparc we don't support SMP kgdb yet.  That
   requires some reworking of the IPI mechanisms and
   infrastructure on that platform.

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 10 insertions, 0 deletions

diff --git a/arch/sparc64/kernel/misctrap.S b/arch/sparc64/kernel/misctrap.S
index b257497ddde1..753b4f031bfb 100644
--- a/arch/sparc64/kernel/misctrap.S
+++ b/arch/sparc64/kernel/misctrap.S
@@ -1,3 +1,13 @@
+#ifdef CONFIG_KGDB
+        .globl          arch_kgdb_breakpoint
+        .type           arch_kgdb_breakpoint,#function
+arch_kgdb_breakpoint:
+        ta              0x72
+        retl
+         nop
+        .size           arch_kgdb_breakpoint,.-arch_kgdb_breakpoint
+#endif
+
         .type           __do_privact,#function
 __do_privact:
         mov             TLB_SFSR, %g3