1 files changed, 19 insertions, 18 deletions

diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index 5971c85df136..4b01a25e29ef 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -146,7 +146,7 @@ END_FW_FTR_SECTION_IFSET(FW_FEATURE_SPLPAR)
         REST_2GPRS(7,r1)
         addi    r9,r1,STACK_FRAME_OVERHEAD
 #endif
-        clrrdi  r11,r1,THREAD_SHIFT
+        CURRENT_THREAD_INFO(r11, r1)
         ld      r10,TI_FLAGS(r11)
         andi.   r11,r10,_TIF_SYSCALL_T_OR_A
         bne-    syscall_dotrace
@@ -181,7 +181,7 @@ syscall_exit:
         bl      .do_show_syscall_exit
         ld      r3,RESULT(r1)
 #endif
-        clrrdi  r12,r1,THREAD_SHIFT
+        CURRENT_THREAD_INFO(r12, r1)
 
         ld      r8,_MSR(r1)
 #ifdef CONFIG_PPC_BOOK3S
@@ -197,7 +197,16 @@ syscall_exit:
         wrteei  0
 #else
         ld      r10,PACAKMSR(r13)
-        mtmsrd  r10,1
+        /*
+         * For performance reasons we clear RI the same time that we
+         * clear EE. We only need to clear RI just before we restore r13
+         * below, but batching it with EE saves us one expensive mtmsrd call.
+         * We have to be careful to restore RI if we branch anywhere from
+         * here (eg syscall_exit_work).
+         */
+        li      r9,MSR_RI
+        andc    r11,r10,r9
+        mtmsrd  r11,1
 #endif /* CONFIG_PPC_BOOK3E */
 
         ld      r9,TI_FLAGS(r12)
@@ -214,17 +223,6 @@ BEGIN_FTR_SECTION
 END_FTR_SECTION_IFCLR(CPU_FTR_STCX_CHECKS_ADDRESS)
         andi.   r6,r8,MSR_PR
         ld      r4,_LINK(r1)
-        /*
-         * Clear RI before restoring r13.  If we are returning to
-         * userspace and we take an exception after restoring r13,
-         * we end up corrupting the userspace r13 value.
-         */
-#ifdef CONFIG_PPC_BOOK3S
-        /* No MSR:RI on BookE */
-        li      r12,MSR_RI
-        andc    r11,r10,r12
-        mtmsrd  r11,1                   /* clear MSR.RI */
-#endif /* CONFIG_PPC_BOOK3S */
 
         beq-    1f
         ACCOUNT_CPU_USER_EXIT(r11, r12)
@@ -262,7 +260,7 @@ syscall_dotrace:
         ld      r7,GPR7(r1)
         ld      r8,GPR8(r1)
         addi    r9,r1,STACK_FRAME_OVERHEAD
-        clrrdi  r10,r1,THREAD_SHIFT
+        CURRENT_THREAD_INFO(r10, r1)
         ld      r10,TI_FLAGS(r10)
         b       .Lsyscall_dotrace_cont
 
@@ -271,6 +269,9 @@ syscall_enosys:
         b       syscall_exit
         
 syscall_exit_work:
+#ifdef CONFIG_PPC_BOOK3S
+        mtmsrd  r10,1           /* Restore RI */
+#endif
         /* If TIF_RESTOREALL is set, don't scribble on either r3 or ccr.
          If TIF_NOERROR is set, just save r3 as it is. */
 
@@ -499,7 +500,7 @@ END_MMU_FTR_SECTION_IFSET(MMU_FTR_1T_SEGMENT)
 2:
 #endif /* !CONFIG_PPC_BOOK3S */
 
-        clrrdi  r7,r8,THREAD_SHIFT      /* base of new stack */
+        CURRENT_THREAD_INFO(r7, r8)  /* base of new stack */
         /* Note: this uses SWITCH_FRAME_SIZE rather than INT_FRAME_SIZE
            because we don't need to leave the 288-byte ABI gap at the
            top of the kernel stack. */
@@ -558,7 +559,7 @@ _GLOBAL(ret_from_except_lite)
         mtmsrd  r10,1             /* Update machine state */
 #endif /* CONFIG_PPC_BOOK3E */
 
-        clrrdi  r9,r1,THREAD_SHIFT      /* current_thread_info() */
+        CURRENT_THREAD_INFO(r9, r1)
         ld      r3,_MSR(r1)
         ld      r4,TI_FLAGS(r9)
         andi.   r3,r3,MSR_PR
@@ -601,7 +602,7 @@ resume_kernel:
 1:      bl      .preempt_schedule_irq
 
         /* Re-test flags and eventually loop */
-        clrrdi  r9,r1,THREAD_SHIFT
+        CURRENT_THREAD_INFO(r9, r1)
         ld      r4,TI_FLAGS(r9)
         andi.   r0,r4,_TIF_NEED_RESCHED
         bne     1b