[IA64] Do not call SN_SAL_SET_CPU_NUMBER twice on cpu 0

This is an SN specific patch.

Architectually, cpu_init is always called twice on cpu 0
and thus resulted in two SN_SAL_SET_CPU_NUMBER calls.

This was harmless in production kernel; however, it can
cause problem on booting up a crashdump kernel at Altix.

Here is the patch that detects the second sn_cpu_init
call and skips the second call to SN_SAL_SET_CPU_NUMBER.

Signed-Off-By: Jay Lan <jlan@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

diff --git a/arch/ia64/sn/kernel/setup.c b/arch/ia64/sn/kernel/setup.c
index a934ad0..8571e52 100644 (file)
--- a/arch/ia64/sn/kernel/setup.c
+++ b/arch/ia64/sn/kernel/setup.c
@@ -580,7 +580,7 @@ void __cpuinit sn_cpu_init(void)
        int slice;
        int cnode;
        int i;
-       static int wars_have_been_checked;
+       static int wars_have_been_checked, set_cpu0_number;
 
        cpuid = smp_processor_id();
        if (cpuid == 0 && IS_MEDUSA()) {
@@ -605,8 +605,16 @@ void __cpuinit sn_cpu_init(void)
        /*
         * Don't check status. The SAL call is not supported on all PROMs
         * but a failure is harmless.
+        * Architechtuallly, cpu_init is always called twice on cpu 0. We
+        * should set cpu_number on cpu 0 once.
         */
-       (void) ia64_sn_set_cpu_number(cpuid);
+       if (cpuid == 0) {
+               if (!set_cpu0_number) {
+                       (void) ia64_sn_set_cpu_number(cpuid);
+                       set_cpu0_number = 1;
+               }
+       } else
+               (void) ia64_sn_set_cpu_number(cpuid);
 
        /*
         * The boot cpu makes this call again after platform initialization is