powerpc/kexec: Wait for online/possible CPUs only.

kexec_perpare_cpus_wait() iterates i through NR_CPUS to check
paca[i].kexec_state of each to make sure they have quiesced.
However now we have dynamic PACA allocation, paca[NR_CPUS] is not necessarily
valid and we overrun the array;  spurious "cpu is not possible, ignoring"
errors result.  This patch iterates for_each_online_cpu so stays
within the bounds of paca[] -- and every CPU is now 'possible'.

Signed-off-by: Matt Evans <matt@ozlabs.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

1 files changed, 1 insertions, 17 deletions

diff --git a/arch/powerpc/kernel/machine_kexec_64.c b/arch/powerpc/kernel/machine_kexec_64.c
index 26f9900f773c..ed31a29c4ff7 100644
--- a/arch/powerpc/kernel/machine_kexec_64.c
+++ b/arch/powerpc/kernel/machine_kexec_64.c
@@ -182,28 +182,12 @@ static void kexec_prepare_cpus_wait(int wait_state)
 
         my_cpu = get_cpu();
         /* Make sure each CPU has atleast made it to the state we need */
-        for (i=0; i < NR_CPUS; i++) {
+        for_each_online_cpu(i) {
                 if (i == my_cpu)
                         continue;
 
                 while (paca[i].kexec_state < wait_state) {
                         barrier();
-                        if (!cpu_possible(i)) {
-                                printk("kexec: cpu %d hw_cpu_id %d is not"
-                                                " possible, ignoring\n",
-                                                i, paca[i].hw_cpu_id);
-                                break;
-                        }
-                        if (!cpu_online(i)) {
-                                /* Fixme: this can be spinning in
-                                 * pSeries_secondary_wait with a paca
-                                 * waiting for it to go online.
-                                 */
-                                printk("kexec: cpu %d hw_cpu_id %d is not"
-                                                " online, ignoring\n",
-                                                i, paca[i].hw_cpu_id);
-                                break;
-                        }
                         if (i != notified) {
                                 printk( "kexec: waiting for cpu %d (physical"
                                                 " %d) to enter %i state\n",