[IA64] Wire in the MCA/INIT handler stacks

Wire the MCA/INIT handler stacks into DTR[2] and track them in
IA64_KR(CURRENT_STACK).  This gives the MCA/INIT handler stacks the
same TLB status as normal kernel stacks.  Reload the old CURRENT_STACK
data on return from OS to SAL.

Signed-off-by: Keith Owens <kaos@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/include/asm-ia64/mca.h b/include/asm-ia64/mca.h
index 97a28b8b2ddd..c7d9c9ed38ba 100644
--- a/include/asm-ia64/mca.h
+++ b/include/asm-ia64/mca.h
@@ -80,7 +80,12 @@ struct ia64_sal_os_state {
         u64                     sal_ra;                 /* Return address in SAL, physical */
         u64                     sal_gp;                 /* GP of the SAL - physical */
         pal_min_state_area_t    *pal_min_state;         /* from R17.  physical in asm, virtual in C */
+        /* Previous values of IA64_KR(CURRENT) and IA64_KR(CURRENT_STACK).
+         * Note: if the MCA/INIT recovery code wants to resume to a new context
+         * then it must change these values to reflect the new kernel stack.
+         */
         u64                     prev_IA64_KR_CURRENT;   /* previous value of IA64_KR(CURRENT) */
+        u64                     prev_IA64_KR_CURRENT_STACK;
         struct task_struct      *prev_task;             /* previous task, NULL if it is not useful */
         /* Some interrupt registers are not saved in minstate, pt_regs or
          * switch_stack.  Because MCA/INIT can occur when interrupts are