1 files changed, 10 insertions, 6 deletions

diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
index 4085aaa9478f..2232aff66059 100644
--- a/arch/powerpc/kernel/setup_64.c
+++ b/arch/powerpc/kernel/setup_64.c
@@ -520,9 +520,6 @@ static void __init irqstack_early_init(void)
 #ifdef CONFIG_PPC_BOOK3E
 static void __init exc_lvl_early_init(void)
 {
-        extern unsigned int interrupt_base_book3e;
-        extern unsigned int exc_debug_debug_book3e;
-
         unsigned int i;
 
         for_each_possible_cpu(i) {
@@ -535,8 +532,7 @@ static void __init exc_lvl_early_init(void)
         }
 
         if (cpu_has_feature(CPU_FTR_DEBUG_LVL_EXC))
-                patch_branch(&interrupt_base_book3e + (0x040 / 4) + 1,
-                             (unsigned long)&exc_debug_debug_book3e, 0);
+                patch_exception(0x040, exc_debug_debug_book3e);
 }
 #else
 #define exc_lvl_early_init()
@@ -544,7 +540,8 @@ static void __init exc_lvl_early_init(void)
 
 /*
  * Stack space used when we detect a bad kernel stack pointer, and
- * early in SMP boots before relocation is enabled.
+ * early in SMP boots before relocation is enabled. Exclusive emergency
+ * stack for machine checks.
  */
 static void __init emergency_stack_init(void)
 {
@@ -567,6 +564,13 @@ static void __init emergency_stack_init(void)
                 sp  = memblock_alloc_base(THREAD_SIZE, THREAD_SIZE, limit);
                 sp += THREAD_SIZE;
                 paca[i].emergency_sp = __va(sp);
+
+#ifdef CONFIG_PPC_BOOK3S_64
+                /* emergency stack for machine check exception handling. */
+                sp  = memblock_alloc_base(THREAD_SIZE, THREAD_SIZE, limit);
+                sp += THREAD_SIZE;
+                paca[i].mc_emergency_sp = __va(sp);
+#endif
         }
 }