[IA64] SN: Add support for CPU disable
Add additional support for CPU disable on SN platforms.
Correctly setup the smp_affinity mask for I/O error IRQs.
Restrict the use of the feature to Altix 4000 and 450 systems
running with a CPU disable capable PROM, and do not allow disabling
of CPU 0.
Signed-off-by: John Keller <jpk@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
diff --git a/arch/ia64/sn/kernel/sn2/sn2_smp.c b/arch/ia64/sn/kernel/sn2/sn2_smp.c
index 033c8a9..f3c6932 100644
--- a/arch/ia64/sn/kernel/sn2/sn2_smp.c
+++ b/arch/ia64/sn/kernel/sn2/sn2_smp.c
@@ -40,6 +40,7 @@
#include <asm/sn/shub_mmr.h>
#include <asm/sn/nodepda.h>
#include <asm/sn/rw_mmr.h>
+#include <asm/sn/sn_feature_sets.h>
DEFINE_PER_CPU(struct ptc_stats, ptcstats);
DECLARE_PER_CPU(struct ptc_stats, ptcstats);
@@ -429,6 +430,31 @@
sn_send_IPI_phys(nasid, physid, vector, delivery_mode);
}
+#ifdef CONFIG_HOTPLUG_CPU
+/**
+ * sn_cpu_disable_allowed - Determine if a CPU can be disabled.
+ * @cpu - CPU that is requested to be disabled.
+ *
+ * CPU disable is only allowed on SHub2 systems running with a PROM
+ * that supports CPU disable. It is not permitted to disable the boot processor.
+ */
+bool sn_cpu_disable_allowed(int cpu)
+{
+ if (is_shub2() && sn_prom_feature_available(PRF_CPU_DISABLE_SUPPORT)) {
+ if (cpu != 0)
+ return true;
+ else
+ printk(KERN_WARNING
+ "Disabling the boot processor is not allowed.\n");
+
+ } else
+ printk(KERN_WARNING
+ "CPU disable is not supported on this system.\n");
+
+ return false;
+}
+#endif /* CONFIG_HOTPLUG_CPU */
+
#ifdef CONFIG_PROC_FS
#define PTC_BASENAME "sgi_sn/ptc_statistics"
