powerpc/64s/idle: POWER9 implement a separate idle stop function for hotplug

Implement a new function to invoke stop, power9_offline_stop, which is
like power9_idle_stop but used by the cpu hotplug code.

Move KVM secondary state manipulation code to the offline case.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

3 files changed, 20 insertions, 7 deletions

diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h
index bb9cb25ffb20..c4b36a494a63 100644
--- a/arch/powerpc/include/asm/processor.h
+++ b/arch/powerpc/include/asm/processor.h
@@ -518,6 +518,7 @@ extern int powersave_nap;	/* set if nap mode can be used in idle loop */
 extern unsigned long power7_idle_insn(unsigned long type); /* PNV_THREAD_NAP/etc*/
 extern void power7_idle_type(unsigned long type);
 extern unsigned long power9_idle_stop(unsigned long psscr_val);
+extern unsigned long power9_offline_stop(unsigned long psscr_val);
 extern void power9_idle_type(unsigned long stop_psscr_val,
                               unsigned long stop_psscr_mask);
 
diff --git a/arch/powerpc/kernel/idle_book3s.S b/arch/powerpc/kernel/idle_book3s.S
index 89157cf452e3..2896ccf3138d 100644
--- a/arch/powerpc/kernel/idle_book3s.S
+++ b/arch/powerpc/kernel/idle_book3s.S
@@ -325,12 +325,6 @@ enter_winkle:
  * r3 - PSSCR value corresponding to the requested stop state.
  */
 power_enter_stop:
-#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
-        /* Tell KVM we're entering idle */
-        li      r4,KVM_HWTHREAD_IN_IDLE
-        /* DO THIS IN REAL MODE!  See comment above. */
-        stb     r4,HSTATE_HWTHREAD_STATE(r13)
-#endif
 /*
  * Check if we are executing the lite variant with ESL=EC=0
  */
@@ -429,6 +423,24 @@ ALT_FTR_SECTION_END_NESTED_IFSET(CPU_FTR_ARCH_207S, 66);		\
  * Entered with MSR[EE]=0 and no soft-masked interrupts pending.
  * r3 contains desired PSSCR register value.
  */
+_GLOBAL(power9_offline_stop)
+        std     r3, PACA_REQ_PSSCR(r13)
+        mtspr   SPRN_PSSCR,r3
+#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
+        /* Tell KVM we're entering idle */
+        li      r4,KVM_HWTHREAD_IN_IDLE
+        /* DO THIS IN REAL MODE!  See comment above. */
+        stb     r4,HSTATE_HWTHREAD_STATE(r13)
+#endif
+        LOAD_REG_ADDR(r4,power_enter_stop)
+        b       pnv_powersave_common
+        /* No return */
+
+
+/*
+ * Entered with MSR[EE]=0 and no soft-masked interrupts pending.
+ * r3 contains desired PSSCR register value.
+ */
 _GLOBAL(power9_idle_stop)
 BEGIN_FTR_SECTION
         lwz     r5, PACA_DONT_STOP(r13)
diff --git a/arch/powerpc/platforms/powernv/idle.c b/arch/powerpc/platforms/powernv/idle.c
index d9e366bb23da..378fde1f85a8 100644
--- a/arch/powerpc/platforms/powernv/idle.c
+++ b/arch/powerpc/platforms/powernv/idle.c
@@ -511,7 +511,7 @@ unsigned long pnv_cpu_offline(unsigned int cpu)
                 psscr = mfspr(SPRN_PSSCR);
                 psscr = (psscr & ~pnv_deepest_stop_psscr_mask) |
                                                 pnv_deepest_stop_psscr_val;
-                srr1 = power9_idle_stop(psscr);
+                srr1 = power9_offline_stop(psscr);
 
         } else if ((idle_states & OPAL_PM_WINKLE_ENABLED) &&
                    (idle_states & OPAL_PM_LOSE_FULL_CONTEXT)) {