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>

diff --git a/arch/powerpc/kernel/machine_kexec_64.c b/arch/powerpc/kernel/machine_kexec_64.c
index 26f9900..ed31a29 100644 (file)
--- 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",