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/******************************************************************************
* hypervisor.c
*
* Communication to/from hypervisor.
*
* Copied from XenoLinux and adjusted by Rolf.Neugebauer@intel.com
*
* Copyright (c) 2002, K A Fraser
*/
#include <os.h>
#include <hypervisor.h>
static unsigned long event_mask = 0;
static unsigned long ev_err_count;
void do_hypervisor_callback(struct pt_regs *regs)
{
unsigned long events, flags;
shared_info_t *shared = HYPERVISOR_shared_info;
do {
/* Specialised local_irq_save(). */
flags = test_and_clear_bit(EVENTS_MASTER_ENABLE_BIT,
&shared->events_mask);
barrier();
events = xchg(&shared->events, 0);
events &= event_mask;
/* 'events' now contains some pending events to handle. */
__asm__ __volatile__ (
" push %1 ;"
" sub $4,%%esp ;"
" jmp 2f ;"
"1: btrl %%eax,%0 ;" /* clear bit */
" mov %%eax,(%%esp) ;"
" call do_event ;" /* do_event(event) */
"2: bsfl %0,%%eax ;" /* %eax == bit # */
" jnz 1b ;"
" add $8,%%esp ;"
/* we use %ebx because it is callee-saved */
: : "b" (events), "r" (regs)
/* clobbered by callback function calls */
: "eax", "ecx", "edx", "memory" );
/* Specialised local_irq_restore(). */
if ( flags ) set_bit(EVENTS_MASTER_ENABLE_BIT, &shared->events_mask);
barrier();
}
while ( shared->events );
}
/*
* Define interface to generic handling in irq.c
*/
void enable_hypervisor_event(unsigned int ev)
{
set_bit(ev, &event_mask);
set_bit(ev, &HYPERVISOR_shared_info->events_mask);
if ( test_bit(EVENTS_MASTER_ENABLE_BIT,
&HYPERVISOR_shared_info->events_mask) )
do_hypervisor_callback(NULL);
}
void disable_hypervisor_event(unsigned int ev)
{
clear_bit(ev, &event_mask);
clear_bit(ev, &HYPERVISOR_shared_info->events_mask);
}
void ack_hypervisor_event(unsigned int ev)
{
if ( !(event_mask & (1<<ev)) )
{
//printk("Unexpected hypervisor event %d\n", ev);
atomic_inc((atomic_t *)&ev_err_count);
}
set_bit(ev, &HYPERVISOR_shared_info->events_mask);
}
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