[IA64] fix boot panic caused by offline CPUs

This fixes a regression introduced by 2c6e6db41f01b6b4eb98809350827c9678996698
"Minimize per_cpu reservations."  That patch incorrectly used information about
what CPUs are possible that was not yet initialized by ACPI.  The end result
was that per_cpu structures for offline CPUs were not initialized causing a
NULL pointer reference.

Since we cannot do the full acpi_boot_init() call any earlier, the simplest
fix is to just parse the MADT for SAPIC entries early to find the CPU
info.  This should also allow for some cleanup of the code added by the
"Minimize per_cpu reservations".  This patch just fixes the regressions, the
cleanup will come in a later patch.

Signed-off-by: Doug Chapman <doug.chapman@hp.com>
Signed-off-by: Alex Chiang <achiang@hp.com>
CC: Robin Holt <holt@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

1 files changed, 4 insertions, 3 deletions

diff --git a/arch/ia64/kernel/setup.c b/arch/ia64/kernel/setup.c
index ae7911702bf8..bf441f49682c 100644
--- a/arch/ia64/kernel/setup.c
+++ b/arch/ia64/kernel/setup.c
@@ -561,8 +561,12 @@ setup_arch (char **cmdline_p)
 #ifdef CONFIG_ACPI
         /* Initialize the ACPI boot-time table parser */
         acpi_table_init();
+        early_acpi_boot_init();
 # ifdef CONFIG_ACPI_NUMA
         acpi_numa_init();
+#ifdef CONFIG_ACPI_HOTPLUG_CPU
+        prefill_possible_map();
+#endif
         per_cpu_scan_finalize((cpus_weight(early_cpu_possible_map) == 0 ?
                 32 : cpus_weight(early_cpu_possible_map)),
                 additional_cpus > 0 ? additional_cpus : 0);
@@ -853,9 +857,6 @@ void __init
 setup_per_cpu_areas (void)
 {
         /* start_kernel() requires this... */
-#ifdef CONFIG_ACPI_HOTPLUG_CPU
-        prefill_possible_map();
-#endif
 }
 
 /*