[PATCH] powerpc: Set nr_cpu_ids early and use it to free PACAs

[Benjamin Herrenschmidt <benh@kernel.crashing.org>]

From: Ryan Grimm <grimm@us.ibm.com>

Without this, "holes" in the CPU numbering can cause us to
free too many PACAs

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
---
 arch/powerpc/kernel/paca.c         |    2 +-
 arch/powerpc/kernel/setup-common.c |    3 +++
 2 files changed, 4 insertions(+), 1 deletions(-)

diff --git a/arch/powerpc/kernel/paca.c b/arch/powerpc/kernel/paca.c
index f4adf89..10f0aad 100644
--- a/arch/powerpc/kernel/paca.c
+++ b/arch/powerpc/kernel/paca.c
@@ -203,7 +203,7 @@ void __init free_unused_pacas(void)
 {
 	int new_size;
 
-	new_size = PAGE_ALIGN(sizeof(struct paca_struct) * num_possible_cpus());
+	new_size = PAGE_ALIGN(sizeof(struct paca_struct) * nr_cpu_ids);
 
 	if (new_size >= paca_size)
 		return;
diff --git a/arch/powerpc/kernel/setup-common.c b/arch/powerpc/kernel/setup-common.c
index 9d4882a..21f30cb 100644
--- a/arch/powerpc/kernel/setup-common.c
+++ b/arch/powerpc/kernel/setup-common.c
@@ -509,6 +509,9 @@ void __init smp_setup_cpu_maps(void)
 	 */
 	cpu_init_thread_core_maps(nthreads);
 
+	/* Now that possible cpus are set, set nr_cpu_ids for later use */
+	nr_cpu_ids = find_last_bit(cpumask_bits(cpu_possible_mask),NR_CPUS) + 1;
+
 	free_unused_pacas();
 }
 #endif /* CONFIG_SMP */