X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=arch%2Fmips%2Fkernel%2Firq.c;h=441157a1f994a4d07cf90ffc248a1e6dc71af5f3;hb=6a77f38946aaee1cd85eeec6cf4229b204c15071;hp=7c1dae7203db22b8c2d68215db82cb77dde7e75c;hpb=87fc8d1bb10cd459024a742c6a10961fefcef18f;p=linux-2.6.git diff --git a/arch/mips/kernel/irq.c b/arch/mips/kernel/irq.c index 7c1dae720..441157a1f 100644 --- a/arch/mips/kernel/irq.c +++ b/arch/mips/kernel/irq.c @@ -28,56 +28,33 @@ #include /* - * Controller mappings for all interrupt sources: + * 'what should we do if we get a hw irq event on an illegal vector'. + * each architecture has to answer this themselves. */ -irq_desc_t irq_desc[NR_IRQS] __cacheline_aligned = { - [0 ... NR_IRQS-1] = { - .handler = &no_irq_type, - .lock = SPIN_LOCK_UNLOCKED - } -}; - -static void register_irq_proc (unsigned int irq); +void ack_bad_irq(unsigned int irq) +{ + printk("unexpected IRQ # %d\n", irq); +} -/* - * Special irq handlers. - */ +atomic_t irq_err_count; -irqreturn_t no_action(int cpl, void *dev_id, struct pt_regs *regs) -{ return IRQ_NONE; } +#undef do_IRQ /* - * Generic no controller code + * do_IRQ handles all normal device IRQ's (the special + * SMP cross-CPU interrupts have their own specific + * handlers). */ - -static void enable_none(unsigned int irq) { } -static unsigned int startup_none(unsigned int irq) { return 0; } -static void disable_none(unsigned int irq) { } -static void ack_none(unsigned int irq) +asmlinkage unsigned int do_IRQ(unsigned int irq, struct pt_regs *regs) { - /* - * 'what should we do if we get a hw irq event on an illegal vector'. - * each architecture has to answer this themselves, it doesn't deserve - * a generic callback i think. - */ - printk("unexpected interrupt %d\n", irq); -} + irq_enter(); -/* startup is the same as "enable", shutdown is same as "disable" */ -#define shutdown_none disable_none -#define end_none enable_none + __do_IRQ(irq, regs); -struct hw_interrupt_type no_irq_type = { - "none", - startup_none, - shutdown_none, - enable_none, - disable_none, - ack_none, - end_none -}; + irq_exit(); -atomic_t irq_err_count; + return 1; +} /* * Generic, controller-independent functions: @@ -126,692 +103,20 @@ skip: return 0; } -#ifdef CONFIG_SMP -inline void synchronize_irq(unsigned int irq) -{ - while (irq_desc[irq].status & IRQ_INPROGRESS) - cpu_relax(); -} -#endif - -/* - * This should really return information about whether - * we should do bottom half handling etc. Right now we - * end up _always_ checking the bottom half, which is a - * waste of time and is not what some drivers would - * prefer. - */ -int handle_IRQ_event(unsigned int irq, struct pt_regs * regs, struct irqaction * action) -{ - int status = 1; /* Force the "do bottom halves" bit */ - int ret, retval = 0; - - if (!(action->flags & SA_INTERRUPT)) - local_irq_enable(); - - do { - ret = action->handler(irq, action->dev_id, regs); - if (ret == IRQ_HANDLED) - status |= action->flags; - retval |= ret; - action = action->next; - } while (action); - if (status & SA_SAMPLE_RANDOM) - add_interrupt_randomness(irq); - local_irq_disable(); - - return retval; -} - -static void __report_bad_irq(int irq, irq_desc_t *desc, irqreturn_t action_ret) -{ - struct irqaction *action; - - if (action_ret != IRQ_HANDLED && action_ret != IRQ_NONE) { - printk(KERN_ERR "irq event %d: bogus return value %x\n", - irq, action_ret); - } else { - printk(KERN_ERR "irq %d: nobody cared!\n", irq); - } - dump_stack(); - printk(KERN_ERR "handlers:\n"); - action = desc->action; - do { - printk(KERN_ERR "[<%p>]", action->handler); - print_symbol(" (%s)", - (unsigned long)action->handler); - printk("\n"); - action = action->next; - } while (action); -} - -static void report_bad_irq(int irq, irq_desc_t *desc, irqreturn_t action_ret) -{ - static int count = 100; - - if (count) { - count--; - __report_bad_irq(irq, desc, action_ret); - } -} - -static int noirqdebug; - -static int __init noirqdebug_setup(char *str) -{ - noirqdebug = 1; - printk("IRQ lockup detection disabled\n"); - return 1; -} - -__setup("noirqdebug", noirqdebug_setup); - -/* - * If 99,900 of the previous 100,000 interrupts have not been handled then - * assume that the IRQ is stuck in some manner. Drop a diagnostic and try to - * turn the IRQ off. - * - * (The other 100-of-100,000 interrupts may have been a correctly-functioning - * device sharing an IRQ with the failing one) - * - * Called under desc->lock - */ -static void note_interrupt(int irq, irq_desc_t *desc, irqreturn_t action_ret) -{ - if (action_ret != IRQ_HANDLED) { - desc->irqs_unhandled++; - if (action_ret != IRQ_NONE) - report_bad_irq(irq, desc, action_ret); - } - - desc->irq_count++; - if (desc->irq_count < 100000) - return; - - desc->irq_count = 0; - if (desc->irqs_unhandled > 99900) { - /* - * The interrupt is stuck - */ - __report_bad_irq(irq, desc, action_ret); - /* - * Now kill the IRQ - */ - printk(KERN_EMERG "Disabling IRQ #%d\n", irq); - desc->status |= IRQ_DISABLED; - desc->handler->disable(irq); - } - desc->irqs_unhandled = 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 of an interrupt - * stack. 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 inline disable_irq_nosync(unsigned int irq) -{ - irq_desc_t *desc = irq_desc + irq; - unsigned long flags; - - spin_lock_irqsave(&desc->lock, flags); - if (!desc->depth++) { - desc->status |= IRQ_DISABLED; - desc->handler->disable(irq); - } - spin_unlock_irqrestore(&desc->lock, flags); -} - -/** - * disable_irq - disable an irq and wait for completion - * @irq: Interrupt to disable - * - * Disable the selected interrupt line. Disables of an interrupt - * stack. That is for two disables you need two enables. 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. - */ +#ifdef CONFIG_KGDB +extern void breakpoint(void); +extern void set_debug_traps(void); -void disable_irq(unsigned int irq) +static int kgdb_flag = 1; +static int __init nokgdb(char *str) { - irq_desc_t *desc = irq_desc + irq; - disable_irq_nosync(irq); - if (desc->action) - synchronize_irq(irq); -} - -/** - * enable_irq - enable interrupt handling on an irq - * @irq: Interrupt to enable - * - * Re-enables the processing of interrupts on this IRQ line - * providing no disable_irq calls are now in effect. - * - * This function may be called from IRQ context. - */ - -void enable_irq(unsigned int irq) -{ - irq_desc_t *desc = irq_desc + irq; - unsigned long flags; - - spin_lock_irqsave(&desc->lock, flags); - switch (desc->depth) { - case 1: { - unsigned int status = desc->status & ~(IRQ_DISABLED | IRQ_INPROGRESS); - desc->status = status; - if ((status & (IRQ_PENDING | IRQ_REPLAY)) == IRQ_PENDING) { - desc->status = status | IRQ_REPLAY; - hw_resend_irq(desc->handler,irq); - } - desc->handler->enable(irq); - /* fall-through */ - } - default: - desc->depth--; - break; - case 0: - printk("enable_irq(%u) unbalanced from %p\n", irq, - __builtin_return_address(0)); - } - spin_unlock_irqrestore(&desc->lock, flags); -} - -/* - * do_IRQ handles all normal device IRQ's (the special - * SMP cross-CPU interrupts have their own specific - * handlers). - */ -asmlinkage unsigned int do_IRQ(int irq, struct pt_regs *regs) -{ - /* - * We ack quickly, we don't want the irq controller - * thinking we're snobs just because some other CPU has - * disabled global interrupts (we have already done the - * INT_ACK cycles, it's too late to try to pretend to the - * controller that we aren't taking the interrupt). - * - * 0 return value means that this irq is already being - * handled by some other CPU. (or is disabled) - */ - irq_desc_t *desc = irq_desc + irq; - struct irqaction * action; - unsigned int status; - - irq_enter(); - kstat_this_cpu.irqs[irq]++; - spin_lock(&desc->lock); - desc->handler->ack(irq); - /* - REPLAY is when Linux resends an IRQ that was dropped earlier - WAITING is used by probe to mark irqs that are being tested - */ - status = desc->status & ~(IRQ_REPLAY | IRQ_WAITING); - status |= IRQ_PENDING; /* we _want_ to handle it */ - - /* - * If the IRQ is disabled for whatever reason, we cannot - * use the action we have. - */ - action = NULL; - if (likely(!(status & (IRQ_DISABLED | IRQ_INPROGRESS)))) { - action = desc->action; - status &= ~IRQ_PENDING; /* we commit to handling */ - status |= IRQ_INPROGRESS; /* we are handling it */ - } - desc->status = status; - - /* - * If there is no IRQ handler or it was disabled, exit early. - Since we set PENDING, if another processor is handling - a different instance of this same irq, the other processor - will take care of it. - */ - if (unlikely(!action)) - goto out; - - /* - * Edge triggered interrupts need to remember - * pending events. - * This applies to any hw interrupts that allow a second - * instance of the same irq to arrive while we are in do_IRQ - * or in the handler. But the code here only handles the _second_ - * instance of the irq, not the third or fourth. So it is mostly - * useful for irq hardware that does not mask cleanly in an - * SMP environment. - */ - for (;;) { - irqreturn_t action_ret; - - spin_unlock(&desc->lock); - action_ret = handle_IRQ_event(irq, regs, action); - spin_lock(&desc->lock); - if (!noirqdebug) - note_interrupt(irq, desc, action_ret); - if (likely(!(desc->status & IRQ_PENDING))) - break; - desc->status &= ~IRQ_PENDING; - } - desc->status &= ~IRQ_INPROGRESS; - -out: - /* - * The ->end() handler has to deal with interrupts which got - * disabled while the handler was running. - */ - desc->handler->end(irq); - spin_unlock(&desc->lock); - - irq_exit(); - + kgdb_flag = 0; return 1; } - -/** - * 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]); - } +__setup("nokgdb", nokgdb); #endif - if (irq >= NR_IRQS) - return -EINVAL; - if (!handler) - return -EINVAL; - - action = (struct irqaction *) - kmalloc(sizeof(struct irqaction), GFP_ATOMIC); - if (!action) - return -ENOMEM; - - action->handler = handler; - action->flags = irqflags; - cpus_clear(action->mask); - 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 must not be called from interrupt context. - */ - -void free_irq(unsigned int irq, void *dev_id) -{ - irq_desc_t *desc; - struct irqaction **p; - unsigned long flags; - - if (irq >= NR_IRQS) - return; - - desc = irq_desc + irq; - spin_lock_irqsave(&desc->lock,flags); - p = &desc->action; - for (;;) { - struct irqaction * action = *p; - if (action) { - struct irqaction **pp = p; - p = &action->next; - if (action->dev_id != dev_id) - continue; - - /* Found it - now remove it from the list of entries */ - *pp = action->next; - if (!desc->action) { - desc->status |= IRQ_DISABLED; - desc->handler->shutdown(irq); - } - spin_unlock_irqrestore(&desc->lock,flags); - - /* Wait to make sure it's not being used on another CPU */ - synchronize_irq(irq); - kfree(action); - return; - } - printk("Trying to free free IRQ%d\n",irq); - spin_unlock_irqrestore(&desc->lock,flags); - return; - } -} - -EXPORT_SYMBOL(free_irq); - -/* - * IRQ autodetection code.. - * - * This depends on the fact that any interrupt that - * comes in on to an unassigned handler will get stuck - * with "IRQ_WAITING" cleared and the interrupt - * disabled. - */ - -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) -{ - unsigned int i; - irq_desc_t *desc; - unsigned long val; - unsigned long delay; - - down(&probe_sem); - /* - * something may have generated an irq long ago and we want to - * flush such a longstanding irq before considering it as spurious. - */ - for (i = NR_IRQS-1; i > 0; i--) { - desc = irq_desc + i; - - spin_lock_irq(&desc->lock); - if (!irq_desc[i].action) - irq_desc[i].handler->startup(i); - spin_unlock_irq(&desc->lock); - } - - /* Wait for longstanding interrupts to trigger. */ - for (delay = jiffies + HZ/50; time_after(delay, jiffies); ) - /* about 20ms delay */ barrier(); - - /* - * enable any unassigned irqs - * (we must startup again here because if a longstanding irq - * happened in the previous stage, it may have masked itself) - */ - for (i = NR_IRQS-1; i > 0; i--) { - desc = irq_desc + i; - - spin_lock_irq(&desc->lock); - if (!desc->action) { - desc->status |= IRQ_AUTODETECT | IRQ_WAITING; - if (desc->handler->startup(i)) - desc->status |= IRQ_PENDING; - } - spin_unlock_irq(&desc->lock); - } - - /* - * Wait for spurious interrupts to trigger - */ - for (delay = jiffies + HZ/10; time_after(delay, jiffies); ) - /* about 100ms delay */ barrier(); - - /* - * Now filter out any obviously spurious interrupts - */ - val = 0; - for (i = 0; i < NR_IRQS; i++) { - irq_desc_t *desc = irq_desc + i; - unsigned int status; - - spin_lock_irq(&desc->lock); - status = desc->status; - - if (status & IRQ_AUTODETECT) { - /* It triggered already - consider it spurious. */ - if (!(status & IRQ_WAITING)) { - desc->status = status & ~IRQ_AUTODETECT; - desc->handler->shutdown(i); - } else - if (i < 32) - val |= 1 << i; - } - spin_unlock_irq(&desc->lock); - } - - return val; -} - -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 val) -{ - int i; - unsigned int mask; - - mask = 0; - for (i = 0; i < NR_IRQS; i++) { - irq_desc_t *desc = irq_desc + i; - unsigned int status; - - spin_lock_irq(&desc->lock); - status = desc->status; - - if (status & IRQ_AUTODETECT) { - if (i < 16 && !(status & IRQ_WAITING)) - mask |= 1 << i; - - desc->status = status & ~IRQ_AUTODETECT; - desc->handler->shutdown(i); - } - spin_unlock_irq(&desc->lock); - } - up(&probe_sem); - - return mask & val; -} - -/* - * Return the one interrupt that triggered (this can - * handle any interrupt source). - */ - -/** - * probe_irq_off - end an interrupt autodetect - * @val: 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 - * there 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 val) -{ - int i, irq_found, nr_irqs; - - nr_irqs = 0; - irq_found = 0; - for (i = 0; i < NR_IRQS; i++) { - irq_desc_t *desc = irq_desc + i; - unsigned int status; - - spin_lock_irq(&desc->lock); - status = desc->status; - - if (status & IRQ_AUTODETECT) { - if (!(status & IRQ_WAITING)) { - if (!nr_irqs) - irq_found = i; - nr_irqs++; - } - desc->status = status & ~IRQ_AUTODETECT; - desc->handler->shutdown(i); - } - spin_unlock_irq(&desc->lock); - } - up(&probe_sem); - - if (nr_irqs > 1) - irq_found = -irq_found; - return irq_found; -} - -EXPORT_SYMBOL(probe_irq_off); - -/* this was setup_x86_irq but it seems pretty generic */ -int setup_irq(unsigned int irq, struct irqaction * new) -{ - int shared = 0; - unsigned long flags; - struct irqaction *old, **p; - irq_desc_t *desc = irq_desc + irq; - - /* - * 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); - } - - /* - * The following block of code has to be executed atomically - */ - spin_lock_irqsave(&desc->lock,flags); - p = &desc->action; - if ((old = *p) != NULL) { - /* Can't share interrupts unless both agree to */ - if (!(old->flags & new->flags & SA_SHIRQ)) { - spin_unlock_irqrestore(&desc->lock,flags); - return -EBUSY; - } - - /* add new interrupt at end of irq queue */ - do { - p = &old->next; - old = *p; - } while (old); - shared = 1; - } - - *p = new; - - if (!shared) { - desc->depth = 0; - desc->status &= ~(IRQ_DISABLED | IRQ_AUTODETECT | IRQ_WAITING | IRQ_INPROGRESS); - desc->handler->startup(irq); - } - spin_unlock_irqrestore(&desc->lock,flags); - - register_irq_proc(irq); - return 0; -} - -void __init init_generic_irq(void) +void __init init_IRQ(void) { int i; @@ -820,108 +125,16 @@ void __init init_generic_irq(void) irq_desc[i].action = NULL; irq_desc[i].depth = 1; irq_desc[i].handler = &no_irq_type; + spin_lock_init(&irq_desc[i].lock); } -} - -EXPORT_SYMBOL(disable_irq_nosync); -EXPORT_SYMBOL(disable_irq); -EXPORT_SYMBOL(enable_irq); -EXPORT_SYMBOL(probe_irq_mask); -static struct proc_dir_entry * root_irq_dir; -static struct proc_dir_entry * irq_dir [NR_IRQS]; + arch_init_irq(); -#ifdef CONFIG_SMP - -static struct proc_dir_entry * smp_affinity_entry [NR_IRQS]; - -static cpumask_t irq_affinity [NR_IRQS] = { [0 ... NR_IRQS-1] = ~0UL }; -static int irq_affinity_read_proc (char *page, char **start, off_t off, - int count, int *eof, void *data) -{ - int len = cpumask_scnprintf(page, count, irq_affinity[(long)data]); - if (count - len < 2) - return -EINVAL; - len += sprintf(page + len, "\n"); - return len; -} - -static int irq_affinity_write_proc (struct file *file, const char *buffer, - unsigned long count, void *data) -{ - int irq = (long) data, full_count = count, err; - cpumask_t new_value, tmp; - - if (!irq_desc[irq].handler->set_affinity) - return -EIO; - - err = cpumask_parse(buffer, count, new_value); - - /* - * Do not allow disabling IRQs completely - it's a too easy - * way to make the system unusable accidentally :-) At least - * one online CPU still has to be targeted. - */ - cpus_and(tmp, new_value, cpu_online_map); - if (cpus_empty(tmp)) - return -EINVAL; - - irq_affinity[irq] = new_value; - irq_desc[irq].handler->set_affinity(irq, new_value); - - return full_count; -} - -#endif - -#define MAX_NAMELEN 10 - -static void register_irq_proc (unsigned int irq) -{ - char name [MAX_NAMELEN]; - - if (!root_irq_dir || (irq_desc[irq].handler == &no_irq_type) || - 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); - -#ifdef CONFIG_SMP - { - struct proc_dir_entry *entry; - - /* create /proc/irq/1234/smp_affinity */ - entry = create_proc_entry("smp_affinity", 0600, irq_dir[irq]); - - if (entry) { - entry->nlink = 1; - entry->data = (void *)(long)irq; - entry->read_proc = irq_affinity_read_proc; - entry->write_proc = irq_affinity_write_proc; - } - - smp_affinity_entry[irq] = entry; +#ifdef CONFIG_KGDB + if (kgdb_flag) { + printk("Wait for gdb client connection ...\n"); + set_debug_traps(); + breakpoint(); } #endif } - -void init_irq_proc (void) -{ - int i; - - /* create /proc/irq */ - root_irq_dir = proc_mkdir("irq", 0); - - /* create /proc/irq/prof_cpu_mask */ - create_prof_cpu_mask(root_irq_dir); - - /* - * Create entries for all existing IRQs. - */ - for (i = 0; i < NR_IRQS; i++) - register_irq_proc(i); -}