linux/arch/sparc64/kernel/irq.c

856 lines
20 KiB
C

/* $Id: irq.c,v 1.114 2002/01/11 08:45:38 davem Exp $
* irq.c: UltraSparc IRQ handling/init/registry.
*
* Copyright (C) 1997 David S. Miller (davem@caip.rutgers.edu)
* Copyright (C) 1998 Eddie C. Dost (ecd@skynet.be)
* Copyright (C) 1998 Jakub Jelinek (jj@ultra.linux.cz)
*/
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/ptrace.h>
#include <linux/errno.h>
#include <linux/kernel_stat.h>
#include <linux/signal.h>
#include <linux/mm.h>
#include <linux/interrupt.h>
#include <linux/slab.h>
#include <linux/random.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/bootmem.h>
#include <linux/irq.h>
#include <linux/msi.h>
#include <asm/ptrace.h>
#include <asm/processor.h>
#include <asm/atomic.h>
#include <asm/system.h>
#include <asm/irq.h>
#include <asm/io.h>
#include <asm/sbus.h>
#include <asm/iommu.h>
#include <asm/upa.h>
#include <asm/oplib.h>
#include <asm/prom.h>
#include <asm/timer.h>
#include <asm/smp.h>
#include <asm/starfire.h>
#include <asm/uaccess.h>
#include <asm/cache.h>
#include <asm/cpudata.h>
#include <asm/auxio.h>
#include <asm/head.h>
/* UPA nodes send interrupt packet to UltraSparc with first data reg
* value low 5 (7 on Starfire) bits holding the IRQ identifier being
* delivered. We must translate this into a non-vector IRQ so we can
* set the softint on this cpu.
*
* To make processing these packets efficient and race free we use
* an array of irq buckets below. The interrupt vector handler in
* entry.S feeds incoming packets into per-cpu pil-indexed lists.
* The IVEC handler does not need to act atomically, the PIL dispatch
* code uses CAS to get an atomic snapshot of the list and clear it
* at the same time.
*
* If you make changes to ino_bucket, please update hand coded assembler
* of the vectored interrupt trap handler(s) in entry.S and sun4v_ivec.S
*/
struct ino_bucket {
/* Next handler in per-CPU IRQ worklist. We know that
* bucket pointers have the high 32-bits clear, so to
* save space we only store the bits we need.
*/
/*0x00*/unsigned int irq_chain;
/* Virtual interrupt number assigned to this INO. */
/*0x04*/unsigned int virt_irq;
};
#define NUM_IVECS (IMAP_INR + 1)
struct ino_bucket ivector_table[NUM_IVECS] __attribute__ ((aligned (SMP_CACHE_BYTES)));
#define __irq_ino(irq) \
(((struct ino_bucket *)(unsigned long)(irq)) - &ivector_table[0])
#define __bucket(irq) ((struct ino_bucket *)(unsigned long)(irq))
#define __irq(bucket) ((unsigned int)(unsigned long)(bucket))
/* This has to be in the main kernel image, it cannot be
* turned into per-cpu data. The reason is that the main
* kernel image is locked into the TLB and this structure
* is accessed from the vectored interrupt trap handler. If
* access to this structure takes a TLB miss it could cause
* the 5-level sparc v9 trap stack to overflow.
*/
#define irq_work(__cpu) &(trap_block[(__cpu)].irq_worklist)
static unsigned int virt_to_real_irq_table[NR_IRQS];
static unsigned char virt_irq_alloc(unsigned int real_irq)
{
unsigned char ent;
BUILD_BUG_ON(NR_IRQS >= 256);
for (ent = 1; ent < NR_IRQS; ent++) {
if (!virt_to_real_irq_table[ent])
break;
}
if (ent >= NR_IRQS) {
printk(KERN_ERR "IRQ: Out of virtual IRQs.\n");
return 0;
}
virt_to_real_irq_table[ent] = real_irq;
return ent;
}
static void virt_irq_free(unsigned int virt_irq)
{
unsigned int real_irq;
if (virt_irq >= NR_IRQS)
return;
real_irq = virt_to_real_irq_table[virt_irq];
virt_to_real_irq_table[virt_irq] = 0;
__bucket(real_irq)->virt_irq = 0;
}
static unsigned int virt_to_real_irq(unsigned char virt_irq)
{
return virt_to_real_irq_table[virt_irq];
}
/*
* /proc/interrupts printing:
*/
int show_interrupts(struct seq_file *p, void *v)
{
int i = *(loff_t *) v, j;
struct irqaction * action;
unsigned long flags;
if (i == 0) {
seq_printf(p, " ");
for_each_online_cpu(j)
seq_printf(p, "CPU%d ",j);
seq_putc(p, '\n');
}
if (i < NR_IRQS) {
spin_lock_irqsave(&irq_desc[i].lock, flags);
action = irq_desc[i].action;
if (!action)
goto skip;
seq_printf(p, "%3d: ",i);
#ifndef CONFIG_SMP
seq_printf(p, "%10u ", kstat_irqs(i));
#else
for_each_online_cpu(j)
seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
#endif
seq_printf(p, " %9s", irq_desc[i].chip->typename);
seq_printf(p, " %s", action->name);
for (action=action->next; action; action = action->next)
seq_printf(p, ", %s", action->name);
seq_putc(p, '\n');
skip:
spin_unlock_irqrestore(&irq_desc[i].lock, flags);
}
return 0;
}
extern unsigned long real_hard_smp_processor_id(void);
static unsigned int sun4u_compute_tid(unsigned long imap, unsigned long cpuid)
{
unsigned int tid;
if (this_is_starfire) {
tid = starfire_translate(imap, cpuid);
tid <<= IMAP_TID_SHIFT;
tid &= IMAP_TID_UPA;
} else {
if (tlb_type == cheetah || tlb_type == cheetah_plus) {
unsigned long ver;
__asm__ ("rdpr %%ver, %0" : "=r" (ver));
if ((ver >> 32UL) == __JALAPENO_ID ||
(ver >> 32UL) == __SERRANO_ID) {
tid = cpuid << IMAP_TID_SHIFT;
tid &= IMAP_TID_JBUS;
} else {
unsigned int a = cpuid & 0x1f;
unsigned int n = (cpuid >> 5) & 0x1f;
tid = ((a << IMAP_AID_SHIFT) |
(n << IMAP_NID_SHIFT));
tid &= (IMAP_AID_SAFARI |
IMAP_NID_SAFARI);;
}
} else {
tid = cpuid << IMAP_TID_SHIFT;
tid &= IMAP_TID_UPA;
}
}
return tid;
}
struct irq_handler_data {
unsigned long iclr;
unsigned long imap;
void (*pre_handler)(unsigned int, void *, void *);
void *pre_handler_arg1;
void *pre_handler_arg2;
};
static inline struct ino_bucket *virt_irq_to_bucket(unsigned int virt_irq)
{
unsigned int real_irq = virt_to_real_irq(virt_irq);
struct ino_bucket *bucket = NULL;
if (likely(real_irq))
bucket = __bucket(real_irq);
return bucket;
}
#ifdef CONFIG_SMP
static int irq_choose_cpu(unsigned int virt_irq)
{
cpumask_t mask = irq_desc[virt_irq].affinity;
int cpuid;
if (cpus_equal(mask, CPU_MASK_ALL)) {
static int irq_rover;
static DEFINE_SPINLOCK(irq_rover_lock);
unsigned long flags;
/* Round-robin distribution... */
do_round_robin:
spin_lock_irqsave(&irq_rover_lock, flags);
while (!cpu_online(irq_rover)) {
if (++irq_rover >= NR_CPUS)
irq_rover = 0;
}
cpuid = irq_rover;
do {
if (++irq_rover >= NR_CPUS)
irq_rover = 0;
} while (!cpu_online(irq_rover));
spin_unlock_irqrestore(&irq_rover_lock, flags);
} else {
cpumask_t tmp;
cpus_and(tmp, cpu_online_map, mask);
if (cpus_empty(tmp))
goto do_round_robin;
cpuid = first_cpu(tmp);
}
return cpuid;
}
#else
static int irq_choose_cpu(unsigned int virt_irq)
{
return real_hard_smp_processor_id();
}
#endif
static void sun4u_irq_enable(unsigned int virt_irq)
{
struct irq_handler_data *data = get_irq_chip_data(virt_irq);
if (likely(data)) {
unsigned long cpuid, imap;
unsigned int tid;
cpuid = irq_choose_cpu(virt_irq);
imap = data->imap;
tid = sun4u_compute_tid(imap, cpuid);
upa_writel(tid | IMAP_VALID, imap);
}
}
static void sun4u_irq_disable(unsigned int virt_irq)
{
struct irq_handler_data *data = get_irq_chip_data(virt_irq);
if (likely(data)) {
unsigned long imap = data->imap;
u32 tmp = upa_readl(imap);
tmp &= ~IMAP_VALID;
upa_writel(tmp, imap);
}
}
static void sun4u_irq_end(unsigned int virt_irq)
{
struct irq_handler_data *data = get_irq_chip_data(virt_irq);
if (likely(data))
upa_writel(ICLR_IDLE, data->iclr);
}
static void sun4v_irq_enable(unsigned int virt_irq)
{
struct ino_bucket *bucket = virt_irq_to_bucket(virt_irq);
unsigned int ino = bucket - &ivector_table[0];
if (likely(bucket)) {
unsigned long cpuid;
int err;
cpuid = irq_choose_cpu(virt_irq);
err = sun4v_intr_settarget(ino, cpuid);
if (err != HV_EOK)
printk("sun4v_intr_settarget(%x,%lu): err(%d)\n",
ino, cpuid, err);
err = sun4v_intr_setenabled(ino, HV_INTR_ENABLED);
if (err != HV_EOK)
printk("sun4v_intr_setenabled(%x): err(%d)\n",
ino, err);
}
}
static void sun4v_irq_disable(unsigned int virt_irq)
{
struct ino_bucket *bucket = virt_irq_to_bucket(virt_irq);
unsigned int ino = bucket - &ivector_table[0];
if (likely(bucket)) {
int err;
err = sun4v_intr_setenabled(ino, HV_INTR_DISABLED);
if (err != HV_EOK)
printk("sun4v_intr_setenabled(%x): "
"err(%d)\n", ino, err);
}
}
#ifdef CONFIG_PCI_MSI
static void sun4v_msi_enable(unsigned int virt_irq)
{
sun4v_irq_enable(virt_irq);
unmask_msi_irq(virt_irq);
}
static void sun4v_msi_disable(unsigned int virt_irq)
{
mask_msi_irq(virt_irq);
sun4v_irq_disable(virt_irq);
}
#endif
static void sun4v_irq_end(unsigned int virt_irq)
{
struct ino_bucket *bucket = virt_irq_to_bucket(virt_irq);
unsigned int ino = bucket - &ivector_table[0];
if (likely(bucket)) {
int err;
err = sun4v_intr_setstate(ino, HV_INTR_STATE_IDLE);
if (err != HV_EOK)
printk("sun4v_intr_setstate(%x): "
"err(%d)\n", ino, err);
}
}
static void run_pre_handler(unsigned int virt_irq)
{
struct ino_bucket *bucket = virt_irq_to_bucket(virt_irq);
struct irq_handler_data *data = get_irq_chip_data(virt_irq);
if (likely(data->pre_handler)) {
data->pre_handler(__irq_ino(__irq(bucket)),
data->pre_handler_arg1,
data->pre_handler_arg2);
}
}
static struct irq_chip sun4u_irq = {
.typename = "sun4u",
.enable = sun4u_irq_enable,
.disable = sun4u_irq_disable,
.end = sun4u_irq_end,
};
static struct irq_chip sun4u_irq_ack = {
.typename = "sun4u+ack",
.enable = sun4u_irq_enable,
.disable = sun4u_irq_disable,
.ack = run_pre_handler,
.end = sun4u_irq_end,
};
static struct irq_chip sun4v_irq = {
.typename = "sun4v",
.enable = sun4v_irq_enable,
.disable = sun4v_irq_disable,
.end = sun4v_irq_end,
};
static struct irq_chip sun4v_irq_ack = {
.typename = "sun4v+ack",
.enable = sun4v_irq_enable,
.disable = sun4v_irq_disable,
.ack = run_pre_handler,
.end = sun4v_irq_end,
};
#ifdef CONFIG_PCI_MSI
static struct irq_chip sun4v_msi = {
.typename = "sun4v+msi",
.mask = mask_msi_irq,
.unmask = unmask_msi_irq,
.enable = sun4v_msi_enable,
.disable = sun4v_msi_disable,
.ack = run_pre_handler,
.end = sun4v_irq_end,
};
#endif
void irq_install_pre_handler(int virt_irq,
void (*func)(unsigned int, void *, void *),
void *arg1, void *arg2)
{
struct irq_handler_data *data = get_irq_chip_data(virt_irq);
struct irq_chip *chip;
data->pre_handler = func;
data->pre_handler_arg1 = arg1;
data->pre_handler_arg2 = arg2;
chip = get_irq_chip(virt_irq);
if (chip == &sun4u_irq_ack ||
chip == &sun4v_irq_ack
#ifdef CONFIG_PCI_MSI
|| chip == &sun4v_msi
#endif
)
return;
chip = (chip == &sun4u_irq ?
&sun4u_irq_ack : &sun4v_irq_ack);
set_irq_chip(virt_irq, chip);
}
unsigned int build_irq(int inofixup, unsigned long iclr, unsigned long imap)
{
struct ino_bucket *bucket;
struct irq_handler_data *data;
int ino;
BUG_ON(tlb_type == hypervisor);
ino = (upa_readl(imap) & (IMAP_IGN | IMAP_INO)) + inofixup;
bucket = &ivector_table[ino];
if (!bucket->virt_irq) {
bucket->virt_irq = virt_irq_alloc(__irq(bucket));
set_irq_chip(bucket->virt_irq, &sun4u_irq);
}
data = get_irq_chip_data(bucket->virt_irq);
if (unlikely(data))
goto out;
data = kzalloc(sizeof(struct irq_handler_data), GFP_ATOMIC);
if (unlikely(!data)) {
prom_printf("IRQ: kzalloc(irq_handler_data) failed.\n");
prom_halt();
}
set_irq_chip_data(bucket->virt_irq, data);
data->imap = imap;
data->iclr = iclr;
out:
return bucket->virt_irq;
}
unsigned int sun4v_build_irq(u32 devhandle, unsigned int devino)
{
struct ino_bucket *bucket;
struct irq_handler_data *data;
unsigned long sysino;
BUG_ON(tlb_type != hypervisor);
sysino = sun4v_devino_to_sysino(devhandle, devino);
bucket = &ivector_table[sysino];
if (!bucket->virt_irq) {
bucket->virt_irq = virt_irq_alloc(__irq(bucket));
set_irq_chip(bucket->virt_irq, &sun4v_irq);
}
data = get_irq_chip_data(bucket->virt_irq);
if (unlikely(data))
goto out;
data = kzalloc(sizeof(struct irq_handler_data), GFP_ATOMIC);
if (unlikely(!data)) {
prom_printf("IRQ: kzalloc(irq_handler_data) failed.\n");
prom_halt();
}
set_irq_chip_data(bucket->virt_irq, data);
/* Catch accidental accesses to these things. IMAP/ICLR handling
* is done by hypervisor calls on sun4v platforms, not by direct
* register accesses.
*/
data->imap = ~0UL;
data->iclr = ~0UL;
out:
return bucket->virt_irq;
}
#ifdef CONFIG_PCI_MSI
unsigned int sun4v_build_msi(u32 devhandle, unsigned int *virt_irq_p,
unsigned int msi_start, unsigned int msi_end)
{
struct ino_bucket *bucket;
struct irq_handler_data *data;
unsigned long sysino;
unsigned int devino;
BUG_ON(tlb_type != hypervisor);
/* Find a free devino in the given range. */
for (devino = msi_start; devino < msi_end; devino++) {
sysino = sun4v_devino_to_sysino(devhandle, devino);
bucket = &ivector_table[sysino];
if (!bucket->virt_irq)
break;
}
if (devino >= msi_end)
return 0;
sysino = sun4v_devino_to_sysino(devhandle, devino);
bucket = &ivector_table[sysino];
bucket->virt_irq = virt_irq_alloc(__irq(bucket));
*virt_irq_p = bucket->virt_irq;
set_irq_chip(bucket->virt_irq, &sun4v_msi);
data = get_irq_chip_data(bucket->virt_irq);
if (unlikely(data))
return devino;
data = kzalloc(sizeof(struct irq_handler_data), GFP_ATOMIC);
if (unlikely(!data)) {
prom_printf("IRQ: kzalloc(irq_handler_data) failed.\n");
prom_halt();
}
set_irq_chip_data(bucket->virt_irq, data);
data->imap = ~0UL;
data->iclr = ~0UL;
return devino;
}
void sun4v_destroy_msi(unsigned int virt_irq)
{
virt_irq_free(virt_irq);
}
#endif
void ack_bad_irq(unsigned int virt_irq)
{
struct ino_bucket *bucket = virt_irq_to_bucket(virt_irq);
unsigned int ino = 0xdeadbeef;
if (bucket)
ino = bucket - &ivector_table[0];
printk(KERN_CRIT "Unexpected IRQ from ino[%x] virt_irq[%u]\n",
ino, virt_irq);
}
#ifndef CONFIG_SMP
extern irqreturn_t timer_interrupt(int, void *);
void timer_irq(int irq, struct pt_regs *regs)
{
unsigned long clr_mask = 1 << irq;
unsigned long tick_mask = tick_ops->softint_mask;
struct pt_regs *old_regs;
if (get_softint() & tick_mask) {
irq = 0;
clr_mask = tick_mask;
}
clear_softint(clr_mask);
old_regs = set_irq_regs(regs);
irq_enter();
kstat_this_cpu.irqs[0]++;
timer_interrupt(irq, NULL);
irq_exit();
set_irq_regs(old_regs);
}
#endif
void handler_irq(int irq, struct pt_regs *regs)
{
struct ino_bucket *bucket;
struct pt_regs *old_regs;
clear_softint(1 << irq);
old_regs = set_irq_regs(regs);
irq_enter();
/* Sliiiick... */
bucket = __bucket(xchg32(irq_work(smp_processor_id()), 0));
while (bucket) {
struct ino_bucket *next = __bucket(bucket->irq_chain);
bucket->irq_chain = 0;
__do_IRQ(bucket->virt_irq);
bucket = next;
}
irq_exit();
set_irq_regs(old_regs);
}
struct sun5_timer {
u64 count0;
u64 limit0;
u64 count1;
u64 limit1;
};
static struct sun5_timer *prom_timers;
static u64 prom_limit0, prom_limit1;
static void map_prom_timers(void)
{
struct device_node *dp;
unsigned int *addr;
/* PROM timer node hangs out in the top level of device siblings... */
dp = of_find_node_by_path("/");
dp = dp->child;
while (dp) {
if (!strcmp(dp->name, "counter-timer"))
break;
dp = dp->sibling;
}
/* Assume if node is not present, PROM uses different tick mechanism
* which we should not care about.
*/
if (!dp) {
prom_timers = (struct sun5_timer *) 0;
return;
}
/* If PROM is really using this, it must be mapped by him. */
addr = of_get_property(dp, "address", NULL);
if (!addr) {
prom_printf("PROM does not have timer mapped, trying to continue.\n");
prom_timers = (struct sun5_timer *) 0;
return;
}
prom_timers = (struct sun5_timer *) ((unsigned long)addr[0]);
}
static void kill_prom_timer(void)
{
if (!prom_timers)
return;
/* Save them away for later. */
prom_limit0 = prom_timers->limit0;
prom_limit1 = prom_timers->limit1;
/* Just as in sun4c/sun4m PROM uses timer which ticks at IRQ 14.
* We turn both off here just to be paranoid.
*/
prom_timers->limit0 = 0;
prom_timers->limit1 = 0;
/* Wheee, eat the interrupt packet too... */
__asm__ __volatile__(
" mov 0x40, %%g2\n"
" ldxa [%%g0] %0, %%g1\n"
" ldxa [%%g2] %1, %%g1\n"
" stxa %%g0, [%%g0] %0\n"
" membar #Sync\n"
: /* no outputs */
: "i" (ASI_INTR_RECEIVE), "i" (ASI_INTR_R)
: "g1", "g2");
}
void init_irqwork_curcpu(void)
{
int cpu = hard_smp_processor_id();
trap_block[cpu].irq_worklist = 0;
}
static void __cpuinit register_one_mondo(unsigned long paddr, unsigned long type)
{
unsigned long num_entries = 128;
unsigned long status;
status = sun4v_cpu_qconf(type, paddr, num_entries);
if (status != HV_EOK) {
prom_printf("SUN4V: sun4v_cpu_qconf(%lu:%lx:%lu) failed, "
"err %lu\n", type, paddr, num_entries, status);
prom_halt();
}
}
static void __cpuinit sun4v_register_mondo_queues(int this_cpu)
{
struct trap_per_cpu *tb = &trap_block[this_cpu];
register_one_mondo(tb->cpu_mondo_pa, HV_CPU_QUEUE_CPU_MONDO);
register_one_mondo(tb->dev_mondo_pa, HV_CPU_QUEUE_DEVICE_MONDO);
register_one_mondo(tb->resum_mondo_pa, HV_CPU_QUEUE_RES_ERROR);
register_one_mondo(tb->nonresum_mondo_pa, HV_CPU_QUEUE_NONRES_ERROR);
}
static void __cpuinit alloc_one_mondo(unsigned long *pa_ptr, int use_bootmem)
{
void *page;
if (use_bootmem)
page = alloc_bootmem_low_pages(PAGE_SIZE);
else
page = (void *) get_zeroed_page(GFP_ATOMIC);
if (!page) {
prom_printf("SUN4V: Error, cannot allocate mondo queue.\n");
prom_halt();
}
*pa_ptr = __pa(page);
}
static void __cpuinit alloc_one_kbuf(unsigned long *pa_ptr, int use_bootmem)
{
void *page;
if (use_bootmem)
page = alloc_bootmem_low_pages(PAGE_SIZE);
else
page = (void *) get_zeroed_page(GFP_ATOMIC);
if (!page) {
prom_printf("SUN4V: Error, cannot allocate kbuf page.\n");
prom_halt();
}
*pa_ptr = __pa(page);
}
static void __cpuinit init_cpu_send_mondo_info(struct trap_per_cpu *tb, int use_bootmem)
{
#ifdef CONFIG_SMP
void *page;
BUILD_BUG_ON((NR_CPUS * sizeof(u16)) > (PAGE_SIZE - 64));
if (use_bootmem)
page = alloc_bootmem_low_pages(PAGE_SIZE);
else
page = (void *) get_zeroed_page(GFP_ATOMIC);
if (!page) {
prom_printf("SUN4V: Error, cannot allocate cpu mondo page.\n");
prom_halt();
}
tb->cpu_mondo_block_pa = __pa(page);
tb->cpu_list_pa = __pa(page + 64);
#endif
}
/* Allocate and register the mondo and error queues for this cpu. */
void __cpuinit sun4v_init_mondo_queues(int use_bootmem, int cpu, int alloc, int load)
{
struct trap_per_cpu *tb = &trap_block[cpu];
if (alloc) {
alloc_one_mondo(&tb->cpu_mondo_pa, use_bootmem);
alloc_one_mondo(&tb->dev_mondo_pa, use_bootmem);
alloc_one_mondo(&tb->resum_mondo_pa, use_bootmem);
alloc_one_kbuf(&tb->resum_kernel_buf_pa, use_bootmem);
alloc_one_mondo(&tb->nonresum_mondo_pa, use_bootmem);
alloc_one_kbuf(&tb->nonresum_kernel_buf_pa, use_bootmem);
init_cpu_send_mondo_info(tb, use_bootmem);
}
if (load) {
if (cpu != hard_smp_processor_id()) {
prom_printf("SUN4V: init mondo on cpu %d not %d\n",
cpu, hard_smp_processor_id());
prom_halt();
}
sun4v_register_mondo_queues(cpu);
}
}
static struct irqaction timer_irq_action = {
.name = "timer",
};
/* Only invoked on boot processor. */
void __init init_IRQ(void)
{
map_prom_timers();
kill_prom_timer();
memset(&ivector_table[0], 0, sizeof(ivector_table));
if (tlb_type == hypervisor)
sun4v_init_mondo_queues(1, hard_smp_processor_id(), 1, 1);
/* We need to clear any IRQ's pending in the soft interrupt
* registers, a spurious one could be left around from the
* PROM timer which we just disabled.
*/
clear_softint(get_softint());
/* Now that ivector table is initialized, it is safe
* to receive IRQ vector traps. We will normally take
* one or two right now, in case some device PROM used
* to boot us wants to speak to us. We just ignore them.
*/
__asm__ __volatile__("rdpr %%pstate, %%g1\n\t"
"or %%g1, %0, %%g1\n\t"
"wrpr %%g1, 0x0, %%pstate"
: /* No outputs */
: "i" (PSTATE_IE)
: "g1");
irq_desc[0].action = &timer_irq_action;
}