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>

3 files changed, 10 insertions, 2 deletions

diff --git a/include/asm-sparc64/kgdb.h b/include/asm-sparc64/kgdb.h
new file mode 100644
index 000000000000..aa6532fd3a13
--- /dev/null
+++ b/include/asm-sparc64/kgdb.h
@@ -0,0 +1 @@
+#include <asm-sparc/kgdb.h>
diff --git a/include/asm-sparc64/system.h b/include/asm-sparc64/system.h
index 53eae091a171..6897ac31be41 100644
--- a/include/asm-sparc64/system.h
+++ b/include/asm-sparc64/system.h
@@ -180,12 +180,13 @@ do {	if (test_thread_flag(TIF_PERFCTR)) {				\
         "ldx    [%%sp + 2047 + 0x70], %%i6\n\t"                         \
         "ldx    [%%sp + 2047 + 0x78], %%i7\n\t"                         \
         "ldx    [%%g6 + %9], %%g4\n\t"                                  \
-        "brz,pt %%o7, 1f\n\t"                                           \
+        "brz,pt %%o7, switch_to_pc\n\t"                                 \
         " mov   %%g7, %0\n\t"                                           \
         "sethi  %%hi(ret_from_syscall), %%g1\n\t"                       \
         "jmpl   %%g1 + %%lo(ret_from_syscall), %%g0\n\t"                \
         " nop\n\t"                                                      \
-        "1:\n\t"                                                        \
+        ".globl switch_to_pc\n\t"                                       \
+        "switch_to_pc:\n\t"                                             \
         : "=&r" (last), "=r" (current), "=r" (current_thread_info_reg), \
           "=r" (__local_per_cpu_offset)                                 \
         : "0" (task_thread_info(next)),                                 \
diff --git a/include/asm-sparc64/ttable.h b/include/asm-sparc64/ttable.h
index d3cc4eff39a6..1b55538b944f 100644
--- a/include/asm-sparc64/ttable.h
+++ b/include/asm-sparc64/ttable.h
@@ -175,6 +175,12 @@
 #define KPROBES_TRAP(lvl) TRAP_ARG(bad_trap, lvl)
 #endif
 
+#ifdef CONFIG_KGDB
+#define KGDB_TRAP(lvl) TRAP_IRQ(kgdb_trap, lvl)
+#else
+#define KGDB_TRAP(lvl) TRAP_ARG(bad_trap, lvl)
+#endif
+
 #define SUN4V_ITSB_MISS                                 \
         ldxa    [%g0] ASI_SCRATCHPAD, %g2;              \
         ldx     [%g2 + HV_FAULT_I_ADDR_OFFSET], %g4;    \