ia64/pv_ops/xen: paravirtualize ivt.S for xen.

paravirtualize ivt.S for xen by multi compile.

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

2 files changed, 67 insertions, 1 deletions

diff --git a/arch/ia64/xen/Makefile b/arch/ia64/xen/Makefile
index 7cb4247f90be..5c87e4a79d39 100644
--- a/arch/ia64/xen/Makefile
+++ b/arch/ia64/xen/Makefile
@@ -2,5 +2,19 @@
 # Makefile for Xen components
 #
 
-obj-y := hypercall.o xensetup.o xen_pv_ops.o \
+obj-y := hypercall.o xenivt.o xensetup.o xen_pv_ops.o \
          hypervisor.o xencomm.o xcom_hcall.o grant-table.o
+
+AFLAGS_xenivt.o += -D__IA64_ASM_PARAVIRTUALIZED_XEN
+
+# xen multi compile
+ASM_PARAVIRT_MULTI_COMPILE_SRCS = ivt.S
+ASM_PARAVIRT_OBJS = $(addprefix xen-,$(ASM_PARAVIRT_MULTI_COMPILE_SRCS:.S=.o))
+obj-y += $(ASM_PARAVIRT_OBJS)
+define paravirtualized_xen
+AFLAGS_$(1) += -D__IA64_ASM_PARAVIRTUALIZED_XEN
+endef
+$(foreach o,$(ASM_PARAVIRT_OBJS),$(eval $(call paravirtualized_xen,$(o))))
+
+$(obj)/xen-%.o: $(src)/../kernel/%.S FORCE
+        $(call if_changed_dep,as_o_S)
diff --git a/arch/ia64/xen/xenivt.S b/arch/ia64/xen/xenivt.S
new file mode 100644
index 000000000000..3e71d50584d9
--- /dev/null
+++ b/arch/ia64/xen/xenivt.S
@@ -0,0 +1,52 @@
+/*
+ * arch/ia64/xen/ivt.S
+ *
+ * Copyright (C) 2005 Hewlett-Packard Co
+ *      Dan Magenheimer <dan.magenheimer@hp.com>
+ *
+ * Copyright (c) 2008 Isaku Yamahata <yamahata at valinux co jp>
+ *                    VA Linux Systems Japan K.K.
+ *                    pv_ops.
+ */
+
+#include <asm/asmmacro.h>
+#include <asm/kregs.h>
+#include <asm/pgtable.h>
+
+#include "../kernel/minstate.h"
+
+        .section .text,"ax"
+GLOBAL_ENTRY(xen_event_callback)
+        mov r31=pr              // prepare to save predicates
+        ;;
+        SAVE_MIN_WITH_COVER     // uses r31; defines r2 and r3
+        ;;
+        movl r3=XSI_PSR_IC
+        mov r14=1
+        ;;
+        st4 [r3]=r14
+        ;;
+        adds r3=8,r2            // set up second base pointer for SAVE_REST
+        srlz.i                  // ensure everybody knows psr.ic is back on
+        ;;
+        SAVE_REST
+        ;;
+1:
+        alloc r14=ar.pfs,0,0,1,0 // must be first in an insn group
+        add out0=16,sp          // pass pointer to pt_regs as first arg
+        ;;
+        br.call.sptk.many b0=xen_evtchn_do_upcall
+        ;;
+        movl r20=XSI_PSR_I_ADDR
+        ;;
+        ld8 r20=[r20]
+        ;;
+        adds r20=-1,r20         // vcpu_info->evtchn_upcall_pending
+        ;;
+        ld1 r20=[r20]
+        ;;
+        cmp.ne p6,p0=r20,r0     // if there are pending events,
+        (p6) br.spnt.few 1b     // call evtchn_do_upcall again.
+        br.sptk.many xen_leave_kernel   // we know ia64_leave_kernel is
+                                        // paravirtualized as xen_leave_kernel
+END(xen_event_callback)