/* irq.c: FRV IRQ handling
*
* Copyright (C) 2003, 2004 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* 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 of the License, or (at your option) any later version.
*/
/*
* (mostly architecture independent, will move to kernel/irq.c in 2.5.)
*
* IRQs are in fact implemented a bit like signal handlers for the kernel.
* Naturally it's not a 1:1 relation, but there are similarities.
*/
#include <linux/config.h>
#include <linux/ptrace.h>
#include <linux/errno.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/ioport.h>
#include <linux/interrupt.h>
#include <linux/timex.h>
#include <linux/slab.h>
#include <linux/random.h>
#include <linux/smp_lock.h>
#include <linux/init.h>
#include <linux/kernel_stat.h>
#include <linux/irq.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/module.h>
#include <asm/atomic.h>
#include <asm/io.h>
#include <asm/smp.h>
#include <asm/system.h>
#include <asm/bitops.h>
#include <asm/uaccess.h>
#include <asm/pgalloc.h>
#include <asm/delay.h>
#include <asm/irq.h>
#include <asm/irc-regs.h>
#include <asm/irq-routing.h>
#include <asm/gdb-stub.h>
extern void __init fpga_init(void);
extern void __init route_mb93493_irqs(void);
static void register_irq_proc (unsigned int irq);
/*
* Special irq handlers.
*/
irqreturn_t no_action(int cpl, void *dev_id, struct pt_regs *regs) { return IRQ_HANDLED; }
atomic_t irq_err_count;
/*
* Generic, controller-independent functions:
*/
int show_interrupts(struct seq_file *p, void *v)
{
struct irqaction *action;
struct irq_group *group;
unsigned long flags;
int level, grp, ix, i, j;
i = *(loff_t *) v;
switch (i) {
case 0:
seq_printf(p, " ");
for (j = 0; j < NR_CPUS; j++)
if (cpu_online(j))
seq_printf(p, "CPU%d ",j);
seq_putc(p, '\n');
break;
case 1 ... NR_IRQ_GROUPS * NR_IRQ_ACTIONS_PER_GROUP:
local_irq_save(flags);
grp = (i - 1) / NR_IRQ_ACTIONS_PER_GROUP;
group = irq_groups[grp];
if (!group)
goto skip;
ix = (i - 1) % NR_IRQ_ACTIONS_PER_GROUP;
action = group->actions[ix];
if (!action)
goto skip;
seq_printf(p, "%3d: ", i - 1);
#ifndef CONFIG_SMP
seq_printf(p, "%10u ", kstat_irqs(i));
#else
for (j = 0; j < NR_CPUS; j++)
if (cpu_online(j))
seq_printf(p, "%10u ", kstat_cpu(j).irqs[i - 1]);
#endif
level = group->sources[ix]->level - frv_irq_levels;
seq_printf(p, " %12s@%x", group->sources[ix]->muxname, level);
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:
local_irq_restore(flags);
break;
case NR_IRQ_GROUPS * NR_IRQ_ACTIONS_PER_GROUP + 1:
seq_printf(p, "ERR: %10u\n", atomic_read(&irq_err_count));
break;
default:
break;
}
return 0;
}
/*
* Generic enable/disable code: this just calls
* down into the PIC-specific version for the actual
* hardware disable after having gotten the irq
* controller lock.
*/
/**
* disable_irq_nosync - disable an irq without waiting
* @irq: Interrupt to disable
*
* Disable the selected interrupt line. Disables and Enables are
* nested.
* Unlike disable_irq(), this function does not ensure existing
* instances of the IRQ handler have completed before returning.
*
* This function may be called from IRQ context.
*/
void disable_irq_nosync(unsigned int irq)
{
struct irq_source *source;
struct irq_group *group;
struct irq_level *level;
unsigned long flags;
int idx = irq & (NR_IRQ_ACTIONS_PER_GROUP - 1);
group = irq_groups[irq >> NR_IRQ_LOG2_ACTIONS_PER_GROUP];
if (!group)
BUG();
source = group->sources[idx];
if (!source)
BUG();
level = source->level;
spin_lock_irqsave(&level->lock, flags);
if (group->control) {
if (!group->disable_cnt[idx]++)
group->control(group, idx, 0);
} else if (!level->disable_count++) {
__set_MASK(level - frv_irq_levels);
}
spin_unlock_irqrestore(&level->lock, flags);
}
EXPORT_SYMBOL(disable_irq_nosync);
/**
* disable_irq - disable an irq and wait for completion
* @irq: Interrupt to disable
*
* Disable the selected interrupt line. Enables and Disables are
* nested.
* This function waits for any pending IRQ handlers for this interrupt
* to complete before returning. If you use this function while
* holding a resource the IRQ handler may need you will deadlock.
*
* This function may be called - with care - from IRQ context.
*/
void disable_irq(unsigned int irq)
{
disable_irq_nosync(irq);
#ifdef CONFIG_SMP
if (!local_irq_count(smp_processor_id())) {
do {
barrier();
} while (irq_desc[irq].status & IRQ_INPROGRESS);
}
#endif
}
EXPORT_SYMBOL(disable_irq);
/**
* enable_irq - enable handling of an irq
* @irq: Interrupt to enable
*
* Undoes the effect of one call to disable_irq(). If this
* matches the last disable, processing of interrupts on this
* IRQ line is re-enabled.
*
* This function may be called from IRQ context.
*/
void enable_irq(unsigned int irq)
{
struct irq_source *source;
struct irq_group *group;
struct irq_level *level;
unsigned long flags;
int idx = irq & (NR_IRQ_ACTIONS_PER_GROUP - 1);
int count;
group = irq_groups[irq >> NR_IRQ_LOG2_ACTIONS_PER_GROUP];
if (!group)
BUG();
source = group->sources[idx];
if (!source)
BUG();
level = source->level;
spin_lock_irqsave(&level->lock, flags);
if (group->control)
count = group->disable_cnt[idx];
else
count = level->disable_count;
switch (count) {
case 1:
if (group->control) {
if (group->actions[idx])
group->control(group, idx, 1);
} else {
if (level->usage)
__clr_MASK(level - frv_irq_levels);
}
/* fall-through */
default:
count--;
break;
case 0:
printk("enable_irq(%u) unbalanced from %p\n", irq, __builtin_return_address(0));
}
if (group->control)
group->disable_cnt[idx] = count;
else
level->disable_count = count;
spin_unlock_irqrestore(&level->lock, flags);
}
EXPORT_SYMBOL(enable_irq);
/*****************************************************************************/
/*
* handles all normal device IRQ's
* - registers are referred to by the __frame variable (GR28)
* - IRQ distribution is complicated in this arch because of the many PICs, the
* way they work and the way they cascade
*/
asmlinkage void do_IRQ(void)
{
struct irq_source *source;
int level, cpu;
level = (__frame->tbr >> 4) & 0xf;
cpu = smp_processor_id();
#if 0
{
static u32 irqcount;
*(volatile u32 *) 0xe1200004 = ~((irqcount++ << 8) | level);
*(volatile u16 *) 0xffc00100 = (u16) ~0x9999;
mb();
}
#endif
if ((unsigned long) __frame - (unsigned long) (current + 1) < 512)
BUG();
__set_MASK(level);
__clr_RC(level);
__clr_IRL();
kstat_this_cpu.irqs[level]++;
irq_enter();
for (source = frv_irq_levels[level].sources; source; source = source->next)
source->doirq(source);
irq_exit();
__clr_MASK(level);
/* only process softirqs if we didn't interrupt another interrupt handler */
if ((__frame->psr & PSR_PIL) == PSR_PIL_0)
if (local_softirq_pending())
do_softirq();
#ifdef CONFIG_PREEMPT
local_irq_disable();
while (--current->preempt_count == 0) {
if (!(__frame->psr & PSR_S) ||
current->need_resched == 0 ||
in_interrupt())
break;
current->preempt_count++;
local_irq_enable();
preempt_schedule();
local_irq_disable();
}
#endif
#if 0
{
*(volatile u16 *) 0xffc00100 = (u16) ~0x6666;
mb();
}
#endif
} /* end do_IRQ() */
/*****************************************************************************/
/*
* handles all NMIs when not co-opted by the debugger
* - registers are referred to by the __frame variable (GR28)
*/
asmlinkage void do_NMI(void)
{
} /* end do_NMI() */
/*****************************************************************************/
/**
* request_irq - allocate an interrupt line
* @irq: Interrupt line to allocate
* @handler: Function to be called when the IRQ occurs
* @irqflags: Interrupt type flags
* @devname: An ascii name for the claiming device
* @dev_id: A cookie passed back to the handler function
*
* This call allocates interrupt resources and enables the
* interrupt line and IRQ handling. From the point this
* call is made your handler function may be invoked. Since
* your handler function must clear any interrupt the board
* raises, you must take care both to initialise your hardware
* and to set up the interrupt handler in the right order.
*
* Dev_id must be globally unique. Normally the address of the
* device data structure is used as the cookie. Since the handler
* receives this value it makes sense to use it.
*
* If your interrupt is shared you must pass a non NULL dev_id
* as this is required when freeing the interrupt.
*
* Flags:
*
* SA_SHIRQ Interrupt is shared
*
* SA_INTERRUPT Disable local interrupts while processing
*
* SA_SAMPLE_RANDOM The interrupt can be used for entropy
*
*/
int request_irq(unsigned int irq,
irqreturn_t (*handler)(int, void *, struct pt_regs *),
unsigned long irqflags,
const char * devname,
void *dev_id)
{
int retval;
struct irqaction *action;
#if 1
/*
* Sanity-check: shared interrupts should REALLY pass in
* a real dev-ID, otherwise we'll have trouble later trying
* to figure out which interrupt is which (messes up the
* interrupt freeing logic etc).
*/
if (irqflags & SA_SHIRQ) {
if (!dev_id)
printk("Bad boy: %s (at 0x%x) called us without a dev_id!\n",
devname, (&irq)[-1]);
}
#endif
if ((irq >> NR_IRQ_LOG2_ACTIONS_PER_GROUP) >= NR_IRQ_GROUPS)
return -EINVAL;
if (!handler)
return -EINVAL;
action = (struct irqaction *) kmalloc(sizeof(struct irqaction), GFP_KERNEL);
if (!action)
return -ENOMEM;
action->handler = handler;
action->flags = irqflags;
action->mask = CPU_MASK_NONE;
action->name = devname;
action->next = NULL;
action->dev_id = dev_id;
retval = setup_irq(irq, action);
if (retval)
kfree(action);
return retval;
}
EXPORT_SYMBOL(request_irq);
/**
* free_irq - free an interrupt
* @irq: Interrupt line to free
* @dev_id: Device identity to free
*
* Remove an interrupt handler. The handler is removed and if the
* interrupt line is no longer in use by any driver it is disabled.
* On a shared IRQ the caller must ensure the interrupt is disabled
* on the card it drives before calling this function. The function
* does not return until any executing interrupts for this IRQ
* have completed.
*
* This function may be called from interrupt context.
*
* Bugs: Attempting to free an irq in a handler for the same irq hangs
* the machine.
*/
void free_irq(unsigned int irq, void *dev_id)
{
struct irq_source *source;
struct irq_group *group;
struct irq_level *level;
struct irqaction **p, **pp;
unsigned long flags;
if ((irq >> NR_IRQ_LOG2_ACTIONS_PER_GROUP) >= NR_IRQ_GROUPS)
return;
group = irq_groups[irq >> NR_IRQ_LOG2_ACTIONS_PER_GROUP];
if (!group)
BUG();
source = group->sources[irq & (NR_IRQ_ACTIONS_PER_GROUP - 1)];
if (!source)
BUG();
level = source->level;
p = &group->actions[irq & (NR_IRQ_ACTIONS_PER_GROUP - 1)];
spin_lock_irqsave(&level->lock, flags);
for (pp = p; *pp; pp = &(*pp)->next) {
struct irqaction *action = *pp;
if (action->dev_id != dev_id)
continue;
/* found it - remove from the list of entries */
*pp = action->next;
level->usage--;
if (p == pp && group->control)
group->control(group, irq & (NR_IRQ_ACTIONS_PER_GROUP - 1), 0);
if (level->usage == 0)
__set_MASK(level - frv_irq_levels);
spin_unlock_irqrestore(&level->lock,flags);
#ifdef CONFIG_SMP
/* Wait to make sure it's not being used on another CPU */
while (desc->status & IRQ_INPROGRESS)
barrier();
#endif
kfree(action);
return;
}
}
EXPORT_SYMBOL(free_irq);
/*
* IRQ autodetection code..
*
* This depends on the fact that any interrupt that comes in on to an
* unassigned IRQ will cause GxICR_DETECT to be set
*/
static DECLARE_MUTEX(probe_sem);
/**
* probe_irq_on - begin an interrupt autodetect
*
* Commence probing for an interrupt. The interrupts are scanned
* and a mask of potential interrupt lines is returned.
*
*/
unsigned long probe_irq_on(void)
{
down(&probe_sem);
return 0;
}
EXPORT_SYMBOL(probe_irq_on);
/*
* Return a mask of triggered interrupts (this
* can handle only legacy ISA interrupts).
*/
/**
* probe_irq_mask - scan a bitmap of interrupt lines
* @val: mask of interrupts to consider
*
* Scan the ISA bus interrupt lines and return a bitmap of
* active interrupts. The interrupt probe logic state is then
* returned to its previous value.
*
* Note: we need to scan all the irq's even though we will
* only return ISA irq numbers - just so that we reset them
* all to a known state.
*/
unsigned int probe_irq_mask(unsigned long xmask)
{
up(&probe_sem);
return 0;
}
EXPORT_SYMBOL(probe_irq_mask);
/*
* Return the one interrupt that triggered (this can
* handle any interrupt source).
*/
/**
* probe_irq_off - end an interrupt autodetect
* @xmask: mask of potential interrupts (unused)
*
* Scans the unused interrupt lines and returns the line which
* appears to have triggered the interrupt. If no interrupt was
* found then zero is returned. If more than one interrupt is
* found then minus the first candidate is returned to indicate
* their is doubt.
*
* The interrupt probe logic state is returned to its previous
* value.
*
* BUGS: When used in a module (which arguably shouldnt happen)
* nothing prevents two IRQ probe callers from overlapping. The
* results of this are non-optimal.
*/
int probe_irq_off(unsigned long xmask)
{
up(&probe_sem);
return -1;
}
EXPORT_SYMBOL(probe_irq_off);
/* this was setup_x86_irq but it seems pretty generic */
int setup_irq(unsigned int irq, struct irqaction *new)
{
struct irq_source *source;
struct irq_group *group;
struct irq_level *level;
struct irqaction **p, **pp;
unsigned long flags;
group = irq_groups[irq >> NR_IRQ_LOG2_ACTIONS_PER_GROUP];
if (!group)
BUG();
source = group->sources[irq & (NR_IRQ_ACTIONS_PER_GROUP - 1)];
if (!source)
BUG();
level = source->level;
p = &group->actions[irq & (NR_IRQ_ACTIONS_PER_GROUP - 1)];
/*
* Some drivers like serial.c use request_irq() heavily,
* so we have to be careful not to interfere with a
* running system.
*/
if (new->flags & SA_SAMPLE_RANDOM) {
/*
* This function might sleep, we want to call it first,
* outside of the atomic block.
* Yes, this might clear the entropy pool if the wrong
* driver is attempted to be loaded, without actually
* installing a new handler, but is this really a problem,
* only the sysadmin is able to do this.
*/
rand_initialize_irq(irq);
}
/* must juggle the interrupt processing stuff with interrupts disabled */
spin_lock_irqsave(&level->lock, flags);
/* can't share interrupts unless all parties agree to */
if (level->usage != 0 && !(level->flags & new->flags & SA_SHIRQ)) {
spin_unlock_irqrestore(&level->lock,flags);
return -EBUSY;
}
/* add new interrupt at end of irq queue */
pp = p;
while (*pp)
pp = &(*pp)->next;
*pp = new;
level->usage++;
level->flags = new->flags;
/* turn the interrupts on */
if (level->usage == 1)
__clr_MASK(level - frv_irq_levels);
if (p == pp && group->control)
group->control(group, irq & (NR_IRQ_ACTIONS_PER_GROUP - 1), 1);
spin_unlock_irqrestore(&level->lock, flags);
register_irq_proc(irq);
return 0;
}
static struct proc_dir_entry * root_irq_dir;
static struct proc_dir_entry * irq_dir [NR_IRQS];
#define HEX_DIGITS 8
static unsigned int parse_hex_value (const char *buffer,
unsigned long count, unsigned long *ret)
{
unsigned char hexnum [HEX_DIGITS];
unsigned long value;
int i;
if (!count)
return -EINVAL;
if (count > HEX_DIGITS)
count = HEX_DIGITS;
if (copy_from_user(hexnum, buffer, count))
return -EFAULT;
/*
* Parse the first 8 characters as a hex string, any non-hex char
* is end-of-string. '00e1', 'e1', '00E1', 'E1' are all the same.
*/
value = 0;
for (i = 0; i < count; i++) {
unsigned int c = hexnum[i];
switch (c) {
case '0' ... '9': c -= '0'; break;
case 'a' ... 'f': c -= 'a'-10; break;
case 'A' ... 'F': c -= 'A'-10; break;
default:
goto out;
}
value = (value << 4) | c;
}
out:
*ret = value;
return 0;
}
static int prof_cpu_mask_read_proc (char *page, char **start, off_t off,
int count, int *eof, void *data)
{
unsigned long *mask = (unsigned long *) data;
if (count < HEX_DIGITS+1)
return -EINVAL;
return sprintf (page, "%08lx\n", *mask);
}
static int prof_cpu_mask_write_proc (struct file *file, const char *buffer,
unsigned long count, void *data)
{
unsigned long *mask = (unsigned long *) data, full_count = count, err;
unsigned long new_value;
show_state();
err = parse_hex_value(buffer, count, &new_value);
if (err)
return err;
*mask = new_value;
return full_count;
}
#define MAX_NAMELEN 10
static void register_irq_proc (unsigned int irq)
{
char name [MAX_NAMELEN];
if (!root_irq_dir || irq_dir[irq])
return;
memset(name, 0, MAX_NAMELEN);
sprintf(name, "%d", irq);
/* create /proc/irq/1234 */
irq_dir[irq] = proc_mkdir(name, root_irq_dir);
}
unsigned long prof_cpu_mask = -1;
void init_irq_proc (void)
{
struct proc_dir_entry *entry;
int i;
/* create /proc/irq */
root_irq_dir = proc_mkdir("irq", 0);
/* create /proc/irq/prof_cpu_mask */
entry = create_proc_entry("prof_cpu_mask", 0600, root_irq_dir);
if (!entry)
return;
entry->nlink = 1;
entry->data = (void *)&prof_cpu_mask;
entry->read_proc = prof_cpu_mask_read_proc;
entry->write_proc = prof_cpu_mask_write_proc;
/*
* Create entries for all existing IRQs.
*/
for (i = 0; i < NR_IRQS; i++)
register_irq_proc(i);
}
/*****************************************************************************/
/*
* initialise the interrupt system
*/
void __init init_IRQ(void)
{
route_cpu_irqs();
fpga_init();
#ifdef CONFIG_FUJITSU_MB93493
route_mb93493_irqs();
#endif
} /* end init_IRQ() */
