/*
* Code to handle x86 style IRQs plus some generic interrupt stuff.
*
* Copyright (C) 1992 Linus Torvalds
* Copyright (C) 1994, 1995, 1996, 1997, 1998 Ralf Baechle
* Copyright (C) 1999 SuSE GmbH (Philipp Rumpf, prumpf@tux.org)
* Copyright (C) 1999-2000 Grant Grundler
* Copyright (c) 2005 Matthew Wilcox
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2, or (at your option)
* any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <linux/bitops.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/kernel_stat.h>
#include <linux/seq_file.h>
#include <linux/spinlock.h>
#include <linux/types.h>
#include <asm/io.h>
#include <asm/smp.h>
#undef PARISC_IRQ_CR16_COUNTS
extern irqreturn_t timer_interrupt(int, void *, struct pt_regs *);
extern irqreturn_t ipi_interrupt(int, void *, struct pt_regs *);
#define EIEM_MASK(irq) (1UL<<(CPU_IRQ_MAX - irq))
/* Bits in EIEM correlate with cpu_irq_action[].
** Numbered *Big Endian*! (ie bit 0 is MSB)
*/
static volatile unsigned long cpu_eiem = 0;
static void cpu_disable_irq(unsigned int irq)
{
unsigned long eirr_bit = EIEM_MASK(irq);
cpu_eiem &= ~eirr_bit;
/* Do nothing on the other CPUs. If they get this interrupt,
* The & cpu_eiem in the do_cpu_irq_mask() ensures they won't
* handle it, and the set_eiem() at the bottom will ensure it
* then gets disabled */
}
static void cpu_enable_irq(unsigned int irq)
{
unsigned long eirr_bit = EIEM_MASK(irq);
cpu_eiem |= eirr_bit;
/* FIXME: while our interrupts aren't nested, we cannot reset
* the eiem mask if we're already in an interrupt. Once we
* implement nested interrupts, this can go away
*/
if (!in_interrupt())
set_eiem(cpu_eiem);
/* This is just a simple NOP IPI. But what it does is cause
* all the other CPUs to do a set_eiem(cpu_eiem) at the end
* of the interrupt handler */
smp_send_all_nop();
}
static unsigned int cpu_startup_irq(unsigned int irq)
{
cpu_enable_irq(irq);
return 0;
}
void no_ack_irq(unsigned int irq) { }
void no_end_irq(unsigned int irq) { }
#ifdef CONFIG_SMP
int cpu_check_affinity(unsigned int irq, cpumask_t *dest)
{
int cpu_dest;
/* timer and ipi have to always be received on all CPUs */
if (irq == TIMER_IRQ || irq == IPI_IRQ) {
/* Bad linux design decision. The mask has already
* been set; we must reset it */
irq_desc[irq].affinity = CPU_MASK_ALL;
return -EINVAL;
}
/* whatever mask they set, we just allow one CPU */
cpu_dest = first_cpu(*dest);
*dest = cpumask_of_cpu(cpu_dest);
return 0;
}
static void cpu_set_affinity_irq(unsigned int irq, cpumask_t dest)
{
if (cpu_check_affinity(irq, &dest))
return;
irq_desc[irq].affinity = dest;
}
#endif
static struct hw_interrupt_type cpu_interrupt_type = {
.typename = "CPU",
.startup = cpu_startup_irq,
.shutdown = cpu_disable_irq,
.enable = cpu_enable_irq,
.disable = cpu_disable_irq,
.ack = no_ack_irq,
.end = no_end_irq,
#ifdef CONFIG_SMP
.set_affinity = cpu_set_affinity_irq,
#endif
/* XXX: Needs to be written. We managed without it so far, but
* we really ought to write it.
*/
.retrigger = NULL,
};
int show_interrupts(struct seq_file *p, void *v)
{
int i = *(loff_t *) v, j;
unsigned long flags;
if (i == 0) {
seq_puts(p, " ");
for_each_online_cpu(j)
seq_printf(p, " CPU%d", j);
#ifdef PARISC_IRQ_CR16_COUNTS
seq_printf(p, " [min/avg/max] (CPU cycle counts)");
#endif
seq_putc(p, '\n');
}
if (i < NR_IRQS) {
struct irqaction *action;
spin_lock_irqsave(&irq_desc[i].lock, flags);
action = irq_desc[i].action;
if (!action)
goto skip;
seq_printf(p, "%3d: ", i);
#ifdef CONFIG_SMP
for_each_online_cpu(j)
seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
#else
seq_printf(p, "%10u ", kstat_irqs(i));
#endif
seq_printf(p, " %14s", irq_desc[i].chip->typename);
#ifndef PARISC_IRQ_CR16_COUNTS
seq_printf(p, " %s", action->name);
while ((action = action->next))
seq_printf(p, ", %s", action->name);
#else
for ( ;action; action = action->next) {
unsigned int k, avg, min, max;
min = max = action->cr16_hist[0];
for (avg = k = 0; k < PARISC_CR16_HIST_SIZE; k++) {
int hist = action->cr16_hist[k];
if (hist) {
avg += hist;
} else
break;
if (hist > max) max = hist;
if (hist < min) min = hist;
}
avg /= k;
seq_printf(p, " %s[%d/%d/%d]", action->name,
min,avg,max);
}
#endif
seq_putc(p, '\n');
skip:
spin_unlock_irqrestore(&irq_desc[i].lock, flags);
}
return 0;
}
/*
** The following form a "set": Virtual IRQ, Transaction Address, Trans Data.
** Respectively, these map to IRQ region+EIRR, Processor HPA, EIRR bit.
**
** To use txn_XXX() interfaces, get a Virtual IRQ first.
** Then use that to get the Transaction address and data.
*/
int cpu_claim_irq(unsigned int irq, struct hw_interrupt_type *type, void *data)
{
if (irq_desc[irq].action)
return -EBUSY;
if (irq_desc[irq].chip != &cpu_interrupt_type)
return -EBUSY;
if (type) {
irq_desc[irq].chip = type;
irq_desc[irq].chip_data = data;
cpu_interrupt_type.enable(irq);
}
return 0;
}
int txn_claim_irq(int irq)
{
return cpu_claim_irq(irq, NULL, NULL) ? -1 : irq;
}
/*
* The bits_wide parameter accommodates the limitations of the HW/SW which
* use these bits:
* Legacy PA I/O (GSC/NIO): 5 bits (architected EIM register)
* V-class (EPIC): 6 bits
* N/L/A-class (iosapic): 8 bits
* PCI 2.2 MSI: 16 bits
* Some PCI devices: 32 bits (Symbios SCSI/ATM/HyperFabric)
*
* On the service provider side:
* o PA 1.1 (and PA2.0 narrow mode) 5-bits (width of EIR register)
* o PA 2.0 wide mode 6-bits (per processor)
* o IA64 8-bits (0-256 total)
*
* So a Legacy PA I/O device on a PA 2.0 box can't use all the bits supported
* by the processor...and the N/L-class I/O subsystem supports more bits than
* PA2.0 has. The first case is the problem.
*/
int txn_alloc_irq(unsigned int bits_wide)
{
int irq;
/* never return irq 0 cause that's the interval timer */
for (irq = CPU_IRQ_BASE + 1; irq <= CPU_IRQ_MAX; irq++) {
if (cpu_claim_irq(irq, NULL, NULL) < 0)
continue;
if ((irq - CPU_IRQ_BASE) >= (1 << bits_wide))
continue;
return irq;
}
/* unlikely, but be prepared */
return -1;
}
unsigned long txn_affinity_addr(unsigned int irq, int cpu)
{
#ifdef CONFIG_SMP
irq_desc[irq].affinity = cpumask_of_cpu(cpu);
#endif
return cpu_data[cpu].txn_addr;
}
unsigned long txn_alloc_addr(unsigned int virt_irq)
{
static int next_cpu = -1;
next_cpu++; /* assign to "next" CPU we want this bugger on */
/* validate entry */
while ((next_cpu < NR_CPUS) && (!cpu_data[next_cpu].txn_addr ||
!cpu_online(next_cpu)))
next_cpu++;
if (next_cpu >= NR_CPUS)
next_cpu = 0; /* nothing else, assign monarch */
return txn_affinity_addr(virt_irq, next_cpu);
}
unsigned int txn_alloc_data(unsigned int virt_irq)
{
return virt_irq - CPU_IRQ_BASE;
}
/* ONLY called from entry.S:intr_extint() */
void do_cpu_irq_mask(struct pt_regs *regs)
{
unsigned long eirr_val;
irq_enter();
/*
* Don't allow TIMER or IPI nested interrupts.
* Allowing any single interrupt to nest can lead to that CPU
* handling interrupts with all enabled interrupts unmasked.
*/
set_eiem(0UL);
/* 1) only process IRQs that are enabled/unmasked (cpu_eiem)
* 2) We loop here on EIRR contents in order to avoid
* nested interrupts or having to take another interrupt
* when we could have just handled it right away.
*/
for (;;) {
unsigned long bit = (1UL << (BITS_PER_LONG - 1));
unsigned int irq;
eirr_val = mfctl(23) & cpu_eiem;
if (!eirr_val)
break;
mtctl(eirr_val, 23); /* reset bits we are going to process */
/* Work our way from MSb to LSb...same order we alloc EIRs */
for (irq = TIMER_IRQ; eirr_val && bit; bit>>=1, irq++) {
#ifdef CONFIG_SMP
cpumask_t dest = irq_desc[irq].affinity;
#endif
if (!(bit & eirr_val))
continue;
/* clear bit in mask - can exit loop sooner */
eirr_val &= ~bit;
#ifdef CONFIG_SMP
/* FIXME: because generic set affinity mucks
* with the affinity before sending it to us
* we can get the situation where the affinity is
* wrong for our CPU type interrupts */
if (irq != TIMER_IRQ && irq != IPI_IRQ &&
!cpu_isset(smp_processor_id(), dest)) {
int cpu = first_cpu(dest);
printk(KERN_DEBUG "redirecting irq %d from CPU %d to %d\n",
irq, smp_processor_id(), cpu);
gsc_writel(irq + CPU_IRQ_BASE,
cpu_data[cpu].hpa);
continue;
}
#endif
__do_IRQ(irq, regs);
}
}
set_eiem(cpu_eiem); /* restore original mask */
irq_exit();
}
static struct irqaction timer_action = {
.handler = timer_interrupt,
.name = "timer",
.flags = SA_INTERRUPT,
};
#ifdef CONFIG_SMP
static struct irqaction ipi_action = {
.handler = ipi_interrupt,
.name = "IPI",
.flags = SA_INTERRUPT,
};
#endif
static void claim_cpu_irqs(void)
{
int i;
for (i = CPU_IRQ_BASE; i <= CPU_IRQ_MAX; i++) {
irq_desc[i].chip = &cpu_interrupt_type;
}
irq_desc[TIMER_IRQ].action = &timer_action;
irq_desc[TIMER_IRQ].status |= IRQ_PER_CPU;
#ifdef CONFIG_SMP
irq_desc[IPI_IRQ].action = &ipi_action;
irq_desc[IPI_IRQ].status = IRQ_PER_CPU;
#endif
}
void __init init_IRQ(void)
{
local_irq_disable(); /* PARANOID - should already be disabled */
mtctl(~0UL, 23); /* EIRR : clear all pending external intr */
claim_cpu_irqs();
#ifdef CONFIG_SMP
if (!cpu_eiem)
cpu_eiem = EIEM_MASK(IPI_IRQ) | EIEM_MASK(TIMER_IRQ);
#else
cpu_eiem = EIEM_MASK(TIMER_IRQ);
#endif
set_eiem(cpu_eiem); /* EIEM : enable all external intr */
}
void ack_bad_irq(unsigned int irq)
{
printk("unexpected IRQ %d\n", irq);
}
