1 files changed, 58 insertions, 41 deletions

diff --git a/arch/powerpc/kernel/rtas.c b/arch/powerpc/kernel/rtas.c
index 214780798289..52e95c2158c0 100644
--- a/arch/powerpc/kernel/rtas.c
+++ b/arch/powerpc/kernel/rtas.c
@@ -19,6 +19,9 @@
 #include <linux/init.h>
 #include <linux/capability.h>
 #include <linux/delay.h>
+#include <linux/smp.h>
+#include <linux/completion.h>
+#include <linux/cpumask.h>
 
 #include <asm/prom.h>
 #include <asm/rtas.h>
@@ -34,6 +37,8 @@
 #include <asm/lmb.h>
 #include <asm/udbg.h>
 #include <asm/syscalls.h>
+#include <asm/smp.h>
+#include <asm/atomic.h>
 
 struct rtas_t rtas = {
         .lock = SPIN_LOCK_UNLOCKED
@@ -41,8 +46,10 @@ struct rtas_t rtas = {
 EXPORT_SYMBOL(rtas);
 
 struct rtas_suspend_me_data {
-        long waiting;
-        struct rtas_args *args;
+        atomic_t working; /* number of cpus accessing this struct */
+        int token; /* ibm,suspend-me */
+        int error;
+        struct completion *complete; /* wait on this until working == 0 */
 };
 
 DEFINE_SPINLOCK(rtas_data_buf_lock);
@@ -657,50 +664,62 @@ static int ibm_suspend_me_token = RTAS_UNKNOWN_SERVICE;
 #ifdef CONFIG_PPC_PSERIES
 static void rtas_percpu_suspend_me(void *info)
 {
-        int i;
         long rc;
-        long flags;
+        unsigned long msr_save;
+        int cpu;
         struct rtas_suspend_me_data *data =
                 (struct rtas_suspend_me_data *)info;
 
-        /*
-         * We use "waiting" to indicate our state.  As long
-         * as it is >0, we are still trying to all join up.
-         * If it goes to 0, we have successfully joined up and
-         * one thread got H_CONTINUE.  If any error happens,
-         * we set it to <0.
-         */
-        local_irq_save(flags);
-        do {
-                rc = plpar_hcall_norets(H_JOIN);
-                smp_rmb();
-        } while (rc == H_SUCCESS && data->waiting > 0);
-        if (rc == H_SUCCESS)
-                goto out;
+        atomic_inc(&data->working);
+
+        /* really need to ensure MSR.EE is off for H_JOIN */
+        msr_save = mfmsr();
+        mtmsr(msr_save & ~(MSR_EE));
+
+        rc = plpar_hcall_norets(H_JOIN);
+
+        mtmsr(msr_save);
 
-        if (rc == H_CONTINUE) {
-                data->waiting = 0;
-                data->args->args[data->args->nargs] =
-                        rtas_call(ibm_suspend_me_token, 0, 1, NULL);
-                for_each_possible_cpu(i)
-                        plpar_hcall_norets(H_PROD,i);
+        if (rc == H_SUCCESS) {
+                /* This cpu was prodded and the suspend is complete. */
+                goto out;
+        } else if (rc == H_CONTINUE) {
+                /* All other cpus are in H_JOIN, this cpu does
+                 * the suspend.
+                 */
+                printk(KERN_DEBUG "calling ibm,suspend-me on cpu %i\n",
+                       smp_processor_id());
+                data->error = rtas_call(data->token, 0, 1, NULL);
+
+                if (data->error)
+                        printk(KERN_DEBUG "ibm,suspend-me returned %d\n",
+                               data->error);
         } else {
-                data->waiting = -EBUSY;
-                printk(KERN_ERR "Error on H_JOIN hypervisor call\n");
+                printk(KERN_ERR "H_JOIN on cpu %i failed with rc = %ld\n",
+                       smp_processor_id(), rc);
+                data->error = rc;
         }
-
+        /* This cpu did the suspend or got an error; in either case,
+         * we need to prod all other other cpus out of join state.
+         * Extra prods are harmless.
+         */
+        for_each_online_cpu(cpu)
+                plpar_hcall_norets(H_PROD, get_hard_smp_processor_id(cpu));
 out:
-        local_irq_restore(flags);
-        return;
+        if (atomic_dec_return(&data->working) == 0)
+                complete(data->complete);
 }
 
 static int rtas_ibm_suspend_me(struct rtas_args *args)
 {
-        int i;
         long state;
         long rc;
         unsigned long retbuf[PLPAR_HCALL_BUFSIZE];
         struct rtas_suspend_me_data data;
+        DECLARE_COMPLETION_ONSTACK(done);
+
+        if (!rtas_service_present("ibm,suspend-me"))
+                return -ENOSYS;
 
         /* Make sure the state is valid */
         rc = plpar_hcall(H_VASI_STATE, retbuf,
@@ -721,25 +740,23 @@ static int rtas_ibm_suspend_me(struct rtas_args *args)
                 return 0;
         }
 
-        data.waiting = 1;
-        data.args = args;
+        atomic_set(&data.working, 0);
+        data.token = rtas_token("ibm,suspend-me");
+        data.error = 0;
+        data.complete = &done;
 
         /* Call function on all CPUs.  One of us will make the
          * rtas call
          */
         if (on_each_cpu(rtas_percpu_suspend_me, &data, 1, 0))
-                data.waiting = -EINVAL;
+                data.error = -EINVAL;
 
-        if (data.waiting != 0)
-                printk(KERN_ERR "Error doing global join\n");
+        wait_for_completion(&done);
 
-        /* Prod each CPU.  This won't hurt, and will wake
-         * anyone we successfully put to sleep with H_JOIN.
-         */
-        for_each_possible_cpu(i)
-                plpar_hcall_norets(H_PROD, i);
+        if (data.error != 0)
+                printk(KERN_ERR "Error doing global join\n");
 
-        return data.waiting;
+        return data.error;
 }
 #else /* CONFIG_PPC_PSERIES */
 static int rtas_ibm_suspend_me(struct rtas_args *args)