1 files changed, 23 insertions, 7 deletions

diff --git a/arch/powerpc/kernel/idle_book3s.S b/arch/powerpc/kernel/idle_book3s.S
index 5f61cc0349c0..6fd08219248d 100644
--- a/arch/powerpc/kernel/idle_book3s.S
+++ b/arch/powerpc/kernel/idle_book3s.S
@@ -276,19 +276,21 @@ power_enter_stop:
  */
         andis.   r4,r3,PSSCR_EC_ESL_MASK_SHIFTED
         clrldi   r3,r3,60 /* r3 = Bits[60:63] = Requested Level (RL) */
-        bne      1f
+        bne      .Lhandle_esl_ec_set
         IDLE_STATE_ENTER_SEQ(PPC_STOP)
         li      r3,0  /* Since we didn't lose state, return 0 */
         b       pnv_wakeup_noloss
+
+.Lhandle_esl_ec_set:
 /*
  * Check if the requested state is a deep idle state.
  */
-1:      LOAD_REG_ADDRBASE(r5,pnv_first_deep_stop_state)
+        LOAD_REG_ADDRBASE(r5,pnv_first_deep_stop_state)
         ld      r4,ADDROFF(pnv_first_deep_stop_state)(r5)
         cmpd    r3,r4
-        bge     2f
+        bge     .Lhandle_deep_stop
         IDLE_STATE_ENTER_SEQ_NORET(PPC_STOP)
-2:
+.Lhandle_deep_stop:
 /*
  * Entering deep idle state.
  * Clear thread bit in PACA_CORE_IDLE_STATE, save SPRs to
@@ -447,9 +449,23 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300)
 _GLOBAL(pnv_wakeup_tb_loss)
         ld      r1,PACAR1(r13)
         /*
-         * Before entering any idle state, the NVGPRs are saved in the stack
-         * and they are restored before switching to the process context. Hence
-         * until they are restored, they are free to be used.
+         * Before entering any idle state, the NVGPRs are saved in the stack.
+         * If there was a state loss, or PACA_NAPSTATELOST was set, then the
+         * NVGPRs are restored. If we are here, it is likely that state is lost,
+         * but not guaranteed -- neither ISA207 nor ISA300 tests to reach
+         * here are the same as the test to restore NVGPRS:
+         * PACA_THREAD_IDLE_STATE test for ISA207, PSSCR test for ISA300,
+         * and SRR1 test for restoring NVGPRs.
+         *
+         * We are about to clobber NVGPRs now, so set NAPSTATELOST to
+         * guarantee they will always be restored. This might be tightened
+         * with careful reading of specs (particularly for ISA300) but this
+         * is already a slow wakeup path and it's simpler to be safe.
+         */
+        li      r0,1
+        stb     r0,PACA_NAPSTATELOST(r13)
+
+        /*
          *
          * Save SRR1 and LR in NVGPRs as they might be clobbered in
          * opal_call() (called in CHECK_HMI_INTERRUPT). SRR1 is required