[POWERPC] Fix per-cpu allocation on oldworld SMP powermacs

The per-cpu area(a) for the secondary CPU(s) isn't getting allocated
on old SMP powermacs that don't have the secondary CPU(s) listed in
the device tree, as per-cpu areas are now only allocated for CPUs in
the cpu_possible_map, and we aren't setting the bits for the secondary
CPU(s) until smp_prepare_cpus(), which is after per-cpu allocation.
Therefore this sets the bits for CPUs 1..3 in cpu_possible_map in
pmac_setup_arch, so they get per-cpu data allocated.

Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 12 insertions, 1 deletions

diff --git a/arch/powerpc/platforms/powermac/setup.c b/arch/powerpc/platforms/powermac/setup.c
index 07b1c4ec428d..956571526a57 100644
--- a/arch/powerpc/platforms/powermac/setup.c
+++ b/arch/powerpc/platforms/powermac/setup.c
@@ -363,8 +363,19 @@ static void __init pmac_setup_arch(void)
                 smp_ops = &core99_smp_ops;
         }
 #ifdef CONFIG_PPC32
-        else
+        else {
+                /*
+                 * We have to set bits in cpu_possible_map here since the
+                 * secondary CPU(s) aren't in the device tree, and
+                 * setup_per_cpu_areas only allocates per-cpu data for
+                 * CPUs in the cpu_possible_map.
+                 */
+                int cpu;
+
+                for (cpu = 1; cpu < 4 && cpu < NR_CPUS; ++cpu)
+                        cpu_set(cpu, cpu_possible_map);
                 smp_ops = &psurge_smp_ops;
+        }
 #endif
 #endif /* CONFIG_SMP */