[IA64] Count disabled cpus as potential hot-pluggable CPUs

Minor updates to earlier patch.
- Added to documentation to add ia64 as well.
- Minor clarification on how to use disabled cpus
- used plain max instead of max_t per Andew Morton.

Signed-off-by: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

1 files changed, 8 insertions, 11 deletions

diff --git a/arch/ia64/kernel/acpi.c b/arch/ia64/kernel/acpi.c
index 34795ede72e0..ecd44bdc8394 100644
--- a/arch/ia64/kernel/acpi.c
+++ b/arch/ia64/kernel/acpi.c
@@ -794,24 +794,21 @@ __init void prefill_possible_map(void)
         int possible, disabled_cpus;
 
         disabled_cpus = total_cpus - available_cpus;
+
         if (additional_cpus == -1) {
-                if (disabled_cpus > 0) {
-                        possible = total_cpus;
+                if (disabled_cpus > 0)
                         additional_cpus = disabled_cpus;
-                }
-                else {
-                        possible = available_cpus;
+                else
                         additional_cpus = 0;
-                }
-        } else {
-                possible = available_cpus + additional_cpus;
-        }
+        }
+
+        possible = available_cpus + additional_cpus;
+
         if (possible > NR_CPUS)
                 possible = NR_CPUS;
 
         printk(KERN_INFO "SMP: Allowing %d CPUs, %d hotplug CPUs\n",
-                possible,
-                max_t(int, additional_cpus, 0));
+                possible, max((possible - available_cpus), 0));
 
         for (i = 0; i < possible; i++)
                 cpu_set(i, cpu_possible_map);