1.1 --- a/linux-2.6.10-xen-sparse/arch/xen/kernel/evtchn.c	Mon Feb 21 19:13:13 2005 +0000
     1.2 +++ b/linux-2.6.10-xen-sparse/arch/xen/kernel/evtchn.c	Tue Feb 22 09:36:11 2005 +0000
     1.3 @@ -92,42 +92,36 @@ void force_evtchn_callback(void)
     1.4      (void)HYPERVISOR_xen_version(0);
     1.5  }
     1.6  
     1.7 +/* NB. Interrupts are disabled on entry. */
     1.8  asmlinkage void evtchn_do_upcall(struct pt_regs *regs)
     1.9  {
    1.10      unsigned long  l1, l2;
    1.11      unsigned int   l1i, l2i, port;
    1.12      int            irq;
    1.13 -    unsigned long  flags;
    1.14      shared_info_t *s = HYPERVISOR_shared_info;
    1.15  
    1.16 -    local_irq_save(flags);
    1.17 -    
    1.18 -    while ( s->vcpu_data[0].evtchn_upcall_pending )
    1.19 +    s->vcpu_data[0].evtchn_upcall_pending = 0;
    1.20 +
    1.21 +    /* NB. No need for a barrier here -- XCHG is a barrier on x86. */
    1.22 +    l1 = xchg(&s->evtchn_pending_sel, 0);
    1.23 +    while ( l1 != 0 )
    1.24      {
    1.25 -        s->vcpu_data[0].evtchn_upcall_pending = 0;
    1.26 -        /* NB. No need for a barrier here -- XCHG is a barrier on x86. */
    1.27 -        l1 = xchg(&s->evtchn_pending_sel, 0);
    1.28 -        while ( (l1i = ffs(l1)) != 0 )
    1.29 -        {
    1.30 -            l1i--;
    1.31 -            l1 &= ~(1 << l1i);
    1.32 +        l1i = __ffs(l1);
    1.33 +        l1 &= ~(1 << l1i);
    1.34          
    1.35 -            l2 = s->evtchn_pending[l1i] & ~s->evtchn_mask[l1i];
    1.36 -            while ( (l2i = ffs(l2)) != 0 )
    1.37 -            {
    1.38 -                l2i--;
    1.39 -                l2 &= ~(1 << l2i);
    1.40 +        l2 = s->evtchn_pending[l1i] & ~s->evtchn_mask[l1i];
    1.41 +        while ( l2 != 0 )
    1.42 +        {
    1.43 +            l2i = __ffs(l2);
    1.44 +            l2 &= ~(1 << l2i);
    1.45              
    1.46 -                port = (l1i << 5) + l2i;
    1.47 -                if ( (irq = evtchn_to_irq[port]) != -1 )
    1.48 -                    do_IRQ(irq, regs);
    1.49 -                else
    1.50 -                    evtchn_device_upcall(port);
    1.51 -            }
    1.52 +            port = (l1i << 5) + l2i;
    1.53 +            if ( (irq = evtchn_to_irq[port]) != -1 )
    1.54 +                do_IRQ(irq, regs);
    1.55 +            else
    1.56 +                evtchn_device_upcall(port);
    1.57          }
    1.58      }
    1.59 -
    1.60 -    local_irq_restore(flags);
    1.61  }
    1.62  
    1.63  static int find_unbound_irq(void)