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/******************************************************************************
* hypervisor.c
*
* Communication to/from hypervisor.
*
* Copyright (c) 2002, K A Fraser
*/
#include <linux/config.h>
#include <asm/atomic.h>
#include <linux/irq.h>
#include <asm/hypervisor.h>
#include <asm/system.h>
#include <asm/ptrace.h>
static unsigned long event_mask = 0;
void frobb(void) {}
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 = shared->events_enable;
shared->events_enable = 0;
barrier();
events = xchg(&shared->events, 0);
events &= event_mask;
__asm__ __volatile__ (
" push %1 ;"
" sub $4,%%esp ;"
" jmp 2f ;"
"1: btrl %%eax,%0 ;" /* clear bit */
" mov %%eax,(%%esp) ;"
" call do_IRQ ;" /* do_IRQ(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(). */
shared->events_enable = flags;
barrier();
}
while ( shared->events );
}
/*
* Define interface to generic handling in irq.c
*/
static unsigned int startup_hypervisor_event(unsigned int irq)
{
set_bit(irq, &event_mask);
return 0;
}
static void shutdown_hypervisor_event(unsigned int irq)
{
clear_bit(irq, &event_mask);
}
static void enable_hypervisor_event(unsigned int irq)
{
set_bit(irq, &event_mask);
}
static void disable_hypervisor_event(unsigned int irq)
{
clear_bit(irq, &event_mask);
}
static void ack_hypervisor_event(unsigned int irq)
{
if ( !(event_mask & (1<<irq)) )
{
printk("Unexpected hypervisor event %d\n", irq);
atomic_inc(&irq_err_count);
}
}
static void end_hypervisor_event(unsigned int irq)
{
}
static struct hw_interrupt_type hypervisor_irq_type = {
"Hypervisor-event",
startup_hypervisor_event,
shutdown_hypervisor_event,
enable_hypervisor_event,
disable_hypervisor_event,
ack_hypervisor_event,
end_hypervisor_event,
NULL
};
void __init init_IRQ(void)
{
int i;
for ( i = 0; i < NR_IRQS; i++ )
{
irq_desc[i].status = IRQ_DISABLED;
irq_desc[i].action = 0;
irq_desc[i].depth = 1;
irq_desc[i].handler = &hypervisor_irq_type;
}
}
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