LXR linux/arch/ia64/xen/xenivt.S

   1/*
   2 * arch/ia64/xen/ivt.S
   3 *
   4 * Copyright (C) 2005 Hewlett-Packard Co
   5 *      Dan Magenheimer <dan.magenheimer@hp.com>
   6 *
   7 * Copyright (c) 2008 Isaku Yamahata <yamahata at valinux co jp>
   8 *                    VA Linux Systems Japan K.K.
   9 *                    pv_ops.
  10 */
  11
  12#include <asm/asmmacro.h>
  13#include <asm/kregs.h>
  14#include <asm/pgtable.h>
  15
  16#include "../kernel/minstate.h"
  17
  18        .section .text,"ax"
  19GLOBAL_ENTRY(xen_event_callback)
  20        mov r31=pr              // prepare to save predicates
  21        ;;
  22        SAVE_MIN_WITH_COVER     // uses r31; defines r2 and r3
  23        ;;
  24        movl r3=XSI_PSR_IC
  25        mov r14=1
  26        ;;
  27        st4 [r3]=r14
  28        ;;
  29        adds r3=8,r2            // set up second base pointer for SAVE_REST
  30        srlz.i                  // ensure everybody knows psr.ic is back on
  31        ;;
  32        SAVE_REST
  33        ;;
  341:
  35        alloc r14=ar.pfs,0,0,1,0 // must be first in an insn group
  36        add out0=16,sp          // pass pointer to pt_regs as first arg
  37        ;;
  38        br.call.sptk.many b0=xen_evtchn_do_upcall
  39        ;;
  40        movl r20=XSI_PSR_I_ADDR
  41        ;;
  42        ld8 r20=[r20]
  43        ;;
  44        adds r20=-1,r20         // vcpu_info->evtchn_upcall_pending
  45        ;;
  46        ld1 r20=[r20]
  47        ;;
  48        cmp.ne p6,p0=r20,r0     // if there are pending events,
  49        (p6) br.spnt.few 1b     // call evtchn_do_upcall again.
  50        br.sptk.many xen_leave_kernel   // we know ia64_leave_kernel is
  51                                        // paravirtualized as xen_leave_kernel
  52END(xen_event_callback)
  53