diff options
Diffstat (limited to 'arch/v850/kernel/irq.c')
| -rw-r--r-- | arch/v850/kernel/irq.c | 744 |
1 files changed, 744 insertions, 0 deletions
diff --git a/arch/v850/kernel/irq.c b/arch/v850/kernel/irq.c new file mode 100644 index 000000000000..336cbf21dc8f --- /dev/null +++ b/arch/v850/kernel/irq.c @@ -0,0 +1,744 @@ +/* + * arch/v850/kernel/irq.c -- High-level interrupt handling + * + * Copyright (C) 2001,02,03,04 NEC Electronics Corporation + * Copyright (C) 2001,02,03,04 Miles Bader <miles@gnu.org> + * Copyright (C) 1994-2000 Ralf Baechle + * Copyright (C) 1992 Linus Torvalds + * + * This file is subject to the terms and conditions of the GNU General + * Public License. See the file COPYING in the main directory of this + * archive for more details. + * + * This file was was derived from the mips version, arch/mips/kernel/irq.c + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/irq.h> +#include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/kernel_stat.h> +#include <linux/slab.h> +#include <linux/mm.h> +#include <linux/random.h> +#include <linux/seq_file.h> + +#include <asm/system.h> + +/* + * Controller mappings for all interrupt sources: + */ +irq_desc_t irq_desc[NR_IRQS] __cacheline_aligned = { + [0 ... NR_IRQS-1] = { + .handler = &no_irq_type, + .lock = SPIN_LOCK_UNLOCKED + } +}; + +/* + * Special irq handlers. + */ + +irqreturn_t no_action(int cpl, void *dev_id, struct pt_regs *regs) +{ + return IRQ_NONE; +} + +/* + * Generic no controller code + */ + +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) +{ + /* + * '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("received IRQ %d with unknown interrupt type\n", irq); +} + +/* startup is the same as "enable", shutdown is same as "disable" */ +#define shutdown_none disable_none +#define end_none enable_none + +struct hw_interrupt_type no_irq_type = { + "none", + startup_none, + shutdown_none, + enable_none, + disable_none, + ack_none, + end_none +}; + +volatile unsigned long irq_err_count, spurious_count; + +/* + * Generic, controller-independent functions: + */ + +int show_interrupts(struct seq_file *p, void *v) +{ + int i = *(loff_t *) v; + struct irqaction * action; + unsigned long flags; + + if (i == 0) { + seq_puts(p, " "); + for (i=0; i < 1 /*smp_num_cpus*/; i++) + seq_printf(p, "CPU%d ", i); + seq_putc(p, '\n'); + } + + if (i < NR_IRQS) { + int j, count, num; + const char *type_name = irq_desc[i].handler->typename; + spin_lock_irqsave(&irq_desc[j].lock, flags); + action = irq_desc[i].action; + if (!action) + goto skip; + + count = 0; + num = -1; + for (j = 0; j < NR_IRQS; j++) + if (irq_desc[j].handler->typename == type_name) { + if (i == j) + num = count; + count++; + } + + seq_printf(p, "%3d: ",i); + seq_printf(p, "%10u ", kstat_irqs(i)); + if (count > 1) { + int prec = (num >= 100 ? 3 : num >= 10 ? 2 : 1); + seq_printf(p, " %*s%d", 14 - prec, type_name, num); + } else + seq_printf(p, " %14s", type_name); + + 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[j].lock, flags); + } else if (i == NR_IRQS) + seq_printf(p, "ERR: %10lu\n", irq_err_count); + return 0; +} + +/* + * 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; + + if (!(action->flags & SA_INTERRUPT)) + local_irq_enable(); + + do { + ret = action->handler(irq, action->dev_id, regs); + if (ret == IRQ_HANDLED) + status |= action->flags; + action = action->next; + } while (action); + if (status & SA_SAMPLE_RANDOM) + add_interrupt_randomness(irq); + local_irq_disable(); + + return status; +} + +/* + * 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. + */ + +void disable_irq(unsigned int irq) +{ + disable_irq_nosync(irq); + 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; + 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); +} + +/* Handle interrupt IRQ. REGS are the registers at the time of ther + interrupt. */ +unsigned int handle_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) + */ + int cpu = smp_processor_id(); + irq_desc_t *desc = irq_desc + irq; + struct irqaction * action; + unsigned int status; + + irq_enter(); + kstat_cpu(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 handle_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 (;;) { + spin_unlock(&desc->lock); + handle_IRQ_event(irq, regs, action); + spin_lock(&desc->lock); + + 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(); + + 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]); + } +#endif + + if (irq >= NR_IRQS) + 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; + 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 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) +{ + 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); + + 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 + * 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 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; +} + +/* Initialize irq handling for IRQs. + BASE_IRQ, BASE_IRQ+INTERVAL, ..., BASE_IRQ+NUM*INTERVAL + to IRQ_TYPE. An IRQ_TYPE of 0 means to use a generic interrupt type. */ +void __init +init_irq_handlers (int base_irq, int num, int interval, + struct hw_interrupt_type *irq_type) +{ + while (num-- > 0) { + irq_desc[base_irq].status = IRQ_DISABLED; + irq_desc[base_irq].action = NULL; + irq_desc[base_irq].depth = 1; + irq_desc[base_irq].handler = irq_type; + base_irq += interval; + } +} + +#if defined(CONFIG_PROC_FS) && defined(CONFIG_SYSCTL) +void init_irq_proc(void) +{ +} +#endif /* CONFIG_PROC_FS && CONFIG_SYSCTL */ |