ia64/pv_ops/xen: paravirtualize read/write ar.itc and ar.itm

paravirtualize ar.itc and ar.itm in order to support save/restore.

Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: Tony Luck <tony.luck@intel.com>

1 files changed, 21 insertions, 0 deletions

diff --git a/arch/ia64/include/asm/xen/inst.h b/arch/ia64/include/asm/xen/inst.h
index e8e01b28d2ae..90537dc15efe 100644
--- a/arch/ia64/include/asm/xen/inst.h
+++ b/arch/ia64/include/asm/xen/inst.h
@@ -113,6 +113,27 @@
 .endm
 #define MOV_FROM_PSR(pred, reg, clob)   __MOV_FROM_PSR pred, reg, clob
 
+/* assuming ar.itc is read with interrupt disabled. */
+#define MOV_FROM_ITC(pred, pred_clob, reg, clob)                \
+(pred)  movl clob = XSI_ITC_OFFSET;                             \
+        ;;                                                      \
+(pred)  ld8 clob = [clob];                                      \
+(pred)  mov reg = ar.itc;                                       \
+        ;;                                                      \
+(pred)  add reg = reg, clob;                                    \
+        ;;                                                      \
+(pred)  movl clob = XSI_ITC_LAST;                               \
+        ;;                                                      \
+(pred)  ld8 clob = [clob];                                      \
+        ;;                                                      \
+(pred)  cmp.geu.unc pred_clob, p0 = clob, reg;                  \
+        ;;                                                      \
+(pred_clob)     add reg = 1, clob;                              \
+        ;;                                                      \
+(pred)  movl clob = XSI_ITC_LAST;                               \
+        ;;                                                      \
+(pred)  st8 [clob] = reg
+
 
 #define MOV_TO_IFA(reg, clob)   \
         movl clob = XSI_IFA;    \