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/******************************************************************************
* hypervisor.c
*
* Communication to/from hypervisor.
*
* Copyright (c) 2002, K A Fraser
*/
#include <linux/config.h>
#include <linux/irq.h>
#include <linux/kernel_stat.h>
#include <asm/atomic.h>
#include <asm/hypervisor.h>
#include <asm/system.h>
#include <asm/ptrace.h>
multicall_entry_t multicall_list[8];
int nr_multicall_ents = 0;
static unsigned long event_mask = 0;
asmlinkage unsigned int do_physirq(int irq, struct pt_regs *regs)
{
int cpu = smp_processor_id();
unsigned long irqs;
shared_info_t *shared = HYPERVISOR_shared_info;
/* do this manually */
kstat.irqs[cpu][irq]++;
ack_hypervisor_event(irq);
barrier();
irqs = xchg(&shared->physirq_pend, 0);
__asm__ __volatile__ (
" push %1 ;"
" sub $4,%%esp ;"
" jmp 3f ;"
"1: btrl %%eax,%0 ;" /* clear bit */
" mov %%eax,(%%esp) ;"
" call do_IRQ ;" /* do_IRQ(event) */
"3: bsfl %0,%%eax ;" /* %eax == bit # */
" jnz 1b ;"
" add $8,%%esp ;"
/* we use %ebx because it is callee-saved */
: : "b" (irqs), "r" (regs)
/* clobbered by callback function calls */
: "eax", "ecx", "edx", "memory" );
/* do this manually */
end_hypervisor_event(irq);
return 0;
}
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;
if ( (events & EVENT_PHYSIRQ) != 0 )
{
do_physirq(_EVENT_PHYSIRQ, regs);
events &= ~EVENT_PHYSIRQ;
}
__asm__ __volatile__ (
" push %1 ;"
" sub $4,%%esp ;"
" jmp 2f ;"
"1: btrl %%eax,%0 ;" /* clear bit */
" add %2,%%eax ;"
" 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), "i" (HYPEREVENT_IRQ_BASE)
/* 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
*/
static void shutdown_hypervisor_event(unsigned int irq)
{
clear_bit(HYPEREVENT_FROM_IRQ(irq), &event_mask);
clear_bit(HYPEREVENT_FROM_IRQ(irq), &HYPERVISOR_shared_info->events_mask);
}
static void enable_hypervisor_event(unsigned int irq)
{
set_bit(HYPEREVENT_FROM_IRQ(irq), &event_mask);
set_bit(HYPEREVENT_FROM_IRQ(irq), &HYPERVISOR_shared_info->events_mask);
if ( test_bit(EVENTS_MASTER_ENABLE_BIT,
&HYPERVISOR_shared_info->events_mask) )
do_hypervisor_callback(NULL);
}
static void disable_hypervisor_event(unsigned int irq)
{
clear_bit(HYPEREVENT_FROM_IRQ(irq), &event_mask);
clear_bit(HYPEREVENT_FROM_IRQ(irq), &HYPERVISOR_shared_info->events_mask);
}
static void ack_hypervisor_event(unsigned int irq)
{
int ev = HYPEREVENT_FROM_IRQ(irq);
if ( !(event_mask & (1<<ev)) )
{
printk("Unexpected hypervisor event %d\n", ev);
atomic_inc(&irq_err_count);
}
set_bit(ev, &HYPERVISOR_shared_info->events_mask);
}
static unsigned int startup_hypervisor_event(unsigned int irq)
{
enable_hypervisor_event(irq);
return 0;
}
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_HYPEREVENT_IRQS; i++ )
{
irq_desc[i + HYPEREVENT_IRQ_BASE].status = IRQ_DISABLED;
irq_desc[i + HYPEREVENT_IRQ_BASE].action = 0;
irq_desc[i + HYPEREVENT_IRQ_BASE].depth = 1;
irq_desc[i + HYPEREVENT_IRQ_BASE].handler = &hypervisor_irq_type;
}
/* Also initialise the physical IRQ handlers. */
physirq_init();
}
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