powerpc/powernv: Use deepest stop state when cpu is offlined

If hardware supports stop state, use the deepest stop state when
the cpu is offlined.

Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Shreyas B. Prabhu <shreyas@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/platforms/powernv/idle.c

@@ -252,6 +252,11 @@ static void power9_idle(void)
  */
 u64 pnv_first_deep_stop_state = MAX_STOP_STATE;
 
+/*
+ * Deepest stop idle state. Used when a cpu is offlined
+ */
+u64 pnv_deepest_stop_state;
+
 /*
  * Power ISA 3.0 idle initialization.
  *
@@ -314,8 +319,11 @@ static int __init pnv_arch300_idle_init(struct device_node *np, u32 *flags,
 	}
 
 	/*
-	 * Set pnv_first_deep_stop_state to the first stop level
-	 * to cause hypervisor state loss
+	 * Set pnv_first_deep_stop_state and pnv_deepest_stop_state.
+	 * pnv_first_deep_stop_state should be set to the first stop
+	 * level to cause hypervisor state loss.
+	 * pnv_deepest_stop_state should be set to the deepest stop
+	 * stop state.
 	 */
 	pnv_first_deep_stop_state = MAX_STOP_STATE;
 	for (i = 0; i < dt_idle_states; i++) {
@@ -324,6 +332,9 @@ static int __init pnv_arch300_idle_init(struct device_node *np, u32 *flags,
 		if ((flags[i] & OPAL_PM_LOSE_FULL_CONTEXT) &&
 		     (pnv_first_deep_stop_state > psscr_rl))
 			pnv_first_deep_stop_state = psscr_rl;
+
+		if (pnv_deepest_stop_state < psscr_rl)
+			pnv_deepest_stop_state = psscr_rl;
 	}
 
 out:

arch/powerpc/platforms/powernv/powernv.h

@@ -18,6 +18,7 @@ static inline void pnv_pci_shutdown(void) { }
 #endif
 
 extern u32 pnv_get_supported_cpuidle_states(void);
+extern u64 pnv_deepest_stop_state;
 
 extern void pnv_lpc_init(void);
 

arch/powerpc/platforms/powernv/smp.c

@@ -182,7 +182,9 @@ static void pnv_smp_cpu_kill_self(void)
 
 		ppc64_runlatch_off();
 
-		if (idle_states & OPAL_PM_WINKLE_ENABLED)
+		if (cpu_has_feature(CPU_FTR_ARCH_300))
+			srr1 = power9_idle_stop(pnv_deepest_stop_state);
+		else if (idle_states & OPAL_PM_WINKLE_ENABLED)
 			srr1 = power7_winkle();
 		else if ((idle_states & OPAL_PM_SLEEP_ENABLED) ||
 				(idle_states & OPAL_PM_SLEEP_ENABLED_ER1))