[IA64] Kexec: Set protection key of identity mapping of EFI in alt_itlb_miss

Set protection key of identity mapping of EFI in alt_itlb_miss.
This will also set the protection key for identity mapped EFI memory
handled by itlb_miss, as it branches to alt_itlb_miss

Without this HP rx3600 machines will not boot

Cc: Isaku Yamahata <yamahata@valinux.co.jp>
Cc: Alex Williamson <alex.williamson@hp.com>
Signed-off-by: Simon Horman <horms@verge.net.au>

Index: xen-unstable.hg/xen/arch/ia64/xen/ivt.S
===================================================================
--- xen-unstable.hg.orig/xen/arch/ia64/xen/ivt.S	2008-02-05 16:18:56.000000000 +0900
+++ xen-unstable.hg/xen/arch/ia64/xen/ivt.S	2008-02-05 16:18:56.000000000 +0900
@@ -186,7 +186,12 @@ ENTRY(alt_itlb_miss)
 	;;
 late_alt_itlb_miss:
 	mov r21=cr.ipsr
+	cmp.eq p6,p0=0x18,r22   // address == 0xe...
+	cmp.eq p7,p0=0x1c,r22   // address == 0xf...
 	movl r17=PAGE_KERNEL
+	;;
+(p6)	movl r17=(__DIRTY_BITS | _PAGE_AR_RWX | _PAGE_PL_PRIV | _PAGE_MA_UC)
+(p7)	movl r17=(__DIRTY_BITS | _PAGE_AR_RWX)
 	movl r19=(((1 << IA64_MAX_PHYS_BITS) - 1) & ~0xfff)
 	;;
 	mov r20=cr.itir