[IA64] bugfix: nptcg breaks cpu-hotadd

If "max_purges" from PAL is 0, it actually means 1.

However it was not handled later when a hot-added cpu pass the
max_purges from PAL.  This makes systems easy to go BUG_ON().

Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

diff --git a/arch/ia64/mm/tlb.c b/arch/ia64/mm/tlb.c
index d52ec4e..8caf424 100644 (file)
--- a/arch/ia64/mm/tlb.c
+++ b/arch/ia64/mm/tlb.c
@@ -168,7 +168,10 @@ setup_ptcg_sem(int max_purges, int nptcg_from)
        static int firstcpu = 1;
 
        if (toolatetochangeptcgsem) {
-               BUG_ON(max_purges < nptcg);
+               if (nptcg_from == NPTCG_FROM_PAL && max_purges == 0)
+                       BUG_ON(1 < nptcg);
+               else
+                       BUG_ON(max_purges < nptcg);
                return;
        }