1 files changed, 21 insertions, 0 deletions

diff --git a/arch/powerpc/kernel/prom_init.c b/arch/powerpc/kernel/prom_init.c
index 12e656ffe60e..5fe2842e8bab 100644
--- a/arch/powerpc/kernel/prom_init.c
+++ b/arch/powerpc/kernel/prom_init.c
@@ -196,6 +196,8 @@ static int __initdata mem_reserve_cnt;
 
 static cell_t __initdata regbuf[1024];
 
+static bool rtas_has_query_cpu_stopped;
+
 
 /*
  * Error results ... some OF calls will return "-1" on error, some
@@ -1574,6 +1576,11 @@ static void __init prom_instantiate_rtas(void)
         prom_setprop(rtas_node, "/rtas", "linux,rtas-entry",
                      &val, sizeof(val));
 
+        /* Check if it supports "query-cpu-stopped-state" */
+        if (prom_getprop(rtas_node, "query-cpu-stopped-state",
+                         &val, sizeof(val)) != PROM_ERROR)
+                rtas_has_query_cpu_stopped = true;
+
 #if defined(CONFIG_PPC_POWERNV) && defined(__BIG_ENDIAN__)
         /* PowerVN takeover hack */
         prom_rtas_data = base;
@@ -1815,6 +1822,18 @@ static void __init prom_hold_cpus(void)
                 = (void *) LOW_ADDR(__secondary_hold_acknowledge);
         unsigned long secondary_hold = LOW_ADDR(__secondary_hold);
 
+        /*
+         * On pseries, if RTAS supports "query-cpu-stopped-state",
+         * we skip this stage, the CPUs will be started by the
+         * kernel using RTAS.
+         */
+        if ((of_platform == PLATFORM_PSERIES ||
+             of_platform == PLATFORM_PSERIES_LPAR) &&
+            rtas_has_query_cpu_stopped) {
+                prom_printf("prom_hold_cpus: skipped\n");
+                return;
+        }
+
         prom_debug("prom_hold_cpus: start...\n");
         prom_debug("    1) spinloop       = 0x%x\n", (unsigned long)spinloop);
         prom_debug("    1) *spinloop      = 0x%x\n", *spinloop);
@@ -3011,6 +3030,8 @@ unsigned long __init prom_init(unsigned long r3, unsigned long r4,
          * On non-powermacs, put all CPUs in spin-loops.
          *
          * PowerMacs use a different mechanism to spin CPUs
+         *
+         * (This must be done after instanciating RTAS)
          */
         if (of_platform != PLATFORM_POWERMAC &&
             of_platform != PLATFORM_OPAL)