1 files changed, 113 insertions, 0 deletions

diff --git a/arch/powerpc/kernel/rtas.c b/arch/powerpc/kernel/rtas.c
index 1fd6e7b2f390..52add6f3e201 100644
--- a/arch/powerpc/kernel/rtas.c
+++ b/arch/powerpc/kernel/rtas.c
@@ -19,6 +19,7 @@
 #include <linux/init.h>
 #include <linux/capability.h>
 #include <linux/delay.h>
+#include <linux/cpu.h>
 #include <linux/smp.h>
 #include <linux/completion.h>
 #include <linux/cpumask.h>
@@ -807,6 +808,95 @@ static void rtas_percpu_suspend_me(void *info)
         __rtas_suspend_cpu((struct rtas_suspend_me_data *)info, 1);
 }
 
+enum rtas_cpu_state {
+        DOWN,
+        UP,
+};
+
+#ifndef CONFIG_SMP
+static int rtas_cpu_state_change_mask(enum rtas_cpu_state state,
+                                cpumask_var_t cpus)
+{
+        if (!cpumask_empty(cpus)) {
+                cpumask_clear(cpus);
+                return -EINVAL;
+        } else
+                return 0;
+}
+#else
+/* On return cpumask will be altered to indicate CPUs changed.
+ * CPUs with states changed will be set in the mask,
+ * CPUs with status unchanged will be unset in the mask. */
+static int rtas_cpu_state_change_mask(enum rtas_cpu_state state,
+                                cpumask_var_t cpus)
+{
+        int cpu;
+        int cpuret = 0;
+        int ret = 0;
+
+        if (cpumask_empty(cpus))
+                return 0;
+
+        for_each_cpu(cpu, cpus) {
+                switch (state) {
+                case DOWN:
+                        cpuret = cpu_down(cpu);
+                        break;
+                case UP:
+                        cpuret = cpu_up(cpu);
+                        break;
+                }
+                if (cpuret) {
+                        pr_debug("%s: cpu_%s for cpu#%d returned %d.\n",
+                                        __func__,
+                                        ((state == UP) ? "up" : "down"),
+                                        cpu, cpuret);
+                        if (!ret)
+                                ret = cpuret;
+                        if (state == UP) {
+                                /* clear bits for unchanged cpus, return */
+                                cpumask_shift_right(cpus, cpus, cpu);
+                                cpumask_shift_left(cpus, cpus, cpu);
+                                break;
+                        } else {
+                                /* clear bit for unchanged cpu, continue */
+                                cpumask_clear_cpu(cpu, cpus);
+                        }
+                }
+        }
+
+        return ret;
+}
+#endif
+
+int rtas_online_cpus_mask(cpumask_var_t cpus)
+{
+        int ret;
+
+        ret = rtas_cpu_state_change_mask(UP, cpus);
+
+        if (ret) {
+                cpumask_var_t tmp_mask;
+
+                if (!alloc_cpumask_var(&tmp_mask, GFP_TEMPORARY))
+                        return ret;
+
+                /* Use tmp_mask to preserve cpus mask from first failure */
+                cpumask_copy(tmp_mask, cpus);
+                rtas_offline_cpus_mask(tmp_mask);
+                free_cpumask_var(tmp_mask);
+        }
+
+        return ret;
+}
+EXPORT_SYMBOL(rtas_online_cpus_mask);
+
+int rtas_offline_cpus_mask(cpumask_var_t cpus)
+{
+        return rtas_cpu_state_change_mask(DOWN, cpus);
+}
+EXPORT_SYMBOL(rtas_offline_cpus_mask);
+
 int rtas_ibm_suspend_me(struct rtas_args *args)
 {
         long state;
@@ -814,6 +904,8 @@ int rtas_ibm_suspend_me(struct rtas_args *args)
         unsigned long retbuf[PLPAR_HCALL_BUFSIZE];
         struct rtas_suspend_me_data data;
         DECLARE_COMPLETION_ONSTACK(done);
+        cpumask_var_t offline_mask;
+        int cpuret;
 
         if (!rtas_service_present("ibm,suspend-me"))
                 return -ENOSYS;
@@ -837,11 +929,24 @@ int rtas_ibm_suspend_me(struct rtas_args *args)
                 return 0;
         }
 
+        if (!alloc_cpumask_var(&offline_mask, GFP_TEMPORARY))
+                return -ENOMEM;
+
         atomic_set(&data.working, 0);
         atomic_set(&data.done, 0);
         atomic_set(&data.error, 0);
         data.token = rtas_token("ibm,suspend-me");
         data.complete = &done;
+
+        /* All present CPUs must be online */
+        cpumask_andnot(offline_mask, cpu_present_mask, cpu_online_mask);
+        cpuret = rtas_online_cpus_mask(offline_mask);
+        if (cpuret) {
+                pr_err("%s: Could not bring present CPUs online.\n", __func__);
+                atomic_set(&data.error, cpuret);
+                goto out;
+        }
+
         stop_topology_update();
 
         /* Call function on all CPUs.  One of us will make the
@@ -857,6 +962,14 @@ int rtas_ibm_suspend_me(struct rtas_args *args)
 
         start_topology_update();
 
+        /* Take down CPUs not online prior to suspend */
+        cpuret = rtas_offline_cpus_mask(offline_mask);
+        if (cpuret)
+                pr_warn("%s: Could not restore CPUs to offline state.\n",
+                                __func__);
+
+out:
+        free_cpumask_var(offline_mask);
         return atomic_read(&data.error);
 }
 #else /* CONFIG_PPC_PSERIES */