diff options
Diffstat (limited to 'arch/arm26/kernel/irq.c')
| -rw-r--r-- | arch/arm26/kernel/irq.c | 722 |
1 files changed, 0 insertions, 722 deletions
diff --git a/arch/arm26/kernel/irq.c b/arch/arm26/kernel/irq.c deleted file mode 100644 index 2ffe695..0000000 --- a/arch/arm26/kernel/irq.c +++ /dev/null @@ -1,722 +0,0 @@ -/* - * linux/arch/arm/kernel/irq.c - * - * Copyright (C) 1992 Linus Torvalds - * Modifications for ARM processor Copyright (C) 1995-2000 Russell King. - * 'Borrowed' for ARM26 and (C) 2003 Ian Molton. - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License version 2 as - * published by the Free Software Foundation. - * - * This file contains the code used by various IRQ handling routines: - * asking for different IRQ's should be done through these routines - * instead of just grabbing them. Thus setups with different IRQ numbers - * shouldn't result in any weird surprises, and installing new handlers - * should be easier. - * - * IRQ's 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/module.h> -#include <linux/ptrace.h> -#include <linux/kernel_stat.h> -#include <linux/signal.h> -#include <linux/sched.h> -#include <linux/ioport.h> -#include <linux/interrupt.h> -#include <linux/slab.h> -#include <linux/random.h> -#include <linux/smp.h> -#include <linux/init.h> -#include <linux/seq_file.h> -#include <linux/errno.h> - -#include <asm/irq.h> -#include <asm/system.h> -#include <asm/irqchip.h> - -//FIXME - this ought to be in a header IMO -void __init arc_init_irq(void); - -/* - * Maximum IRQ count. Currently, this is arbitary. However, it should - * not be set too low to prevent false triggering. Conversely, if it - * is set too high, then you could miss a stuck IRQ. - * - * FIXME Maybe we ought to set a timer and re-enable the IRQ at a later time? - */ -#define MAX_IRQ_CNT 100000 - -static volatile unsigned long irq_err_count; -static DEFINE_SPINLOCK(irq_controller_lock); - -struct irqdesc irq_desc[NR_IRQS]; - -/* - * Dummy mask/unmask handler - */ -void dummy_mask_unmask_irq(unsigned int irq) -{ -} - -void do_bad_IRQ(unsigned int irq, struct irqdesc *desc, struct pt_regs *regs) -{ - irq_err_count += 1; - printk(KERN_ERR "IRQ: spurious interrupt %d\n", irq); -} - -static struct irqchip bad_chip = { - .ack = dummy_mask_unmask_irq, - .mask = dummy_mask_unmask_irq, - .unmask = dummy_mask_unmask_irq, -}; - -static struct irqdesc bad_irq_desc = { - .chip = &bad_chip, - .handle = do_bad_IRQ, - .depth = 1, -}; - -/** - * disable_irq - disable an irq and wait for completion - * @irq: Interrupt to disable - * - * Disable the selected interrupt line. We do this lazily. - * - * This function may be called from IRQ context. - */ -void disable_irq(unsigned int irq) -{ - struct irqdesc *desc = irq_desc + irq; - unsigned long flags; - spin_lock_irqsave(&irq_controller_lock, flags); - if (!desc->depth++) - desc->enabled = 0; - spin_unlock_irqrestore(&irq_controller_lock, flags); -} -EXPORT_SYMBOL(disable_irq); - -void disable_irq_nosync(unsigned int irq) __attribute__((alias("disable_irq"))); - -EXPORT_SYMBOL(disable_irq_nosync); - -/** - * enable_irq - enable interrupt handling on an irq - * @irq: Interrupt to enable - * - * Re-enables the processing of interrupts on this IRQ line. - * Note that this may call the interrupt handler, so you may - * get unexpected results if you hold IRQs disabled. - * - * This function may be called from IRQ context. - */ -void enable_irq(unsigned int irq) -{ - struct irqdesc *desc = irq_desc + irq; - unsigned long flags; - int pending = 0; - - spin_lock_irqsave(&irq_controller_lock, flags); - if (unlikely(!desc->depth)) { - printk("enable_irq(%u) unbalanced from %p\n", irq, - __builtin_return_address(0)); //FIXME bum addresses reported - why? - } else if (!--desc->depth) { - desc->probing = 0; - desc->enabled = 1; - desc->chip->unmask(irq); - pending = desc->pending; - desc->pending = 0; - /* - * If the interrupt was waiting to be processed, - * retrigger it. - */ - if (pending) - desc->chip->rerun(irq); - } - spin_unlock_irqrestore(&irq_controller_lock, flags); -} -EXPORT_SYMBOL(enable_irq); - -int show_interrupts(struct seq_file *p, void *v) -{ - int i = *(loff_t *) v; - struct irqaction * action; - - if (i < NR_IRQS) { - action = irq_desc[i].action; - if (!action) - goto out; - seq_printf(p, "%3d: %10u ", i, kstat_irqs(i)); - seq_printf(p, " %s", action->name); - for (action = action->next; action; action = action->next) { - seq_printf(p, ", %s", action->name); - } - seq_putc(p, '\n'); - } else if (i == NR_IRQS) { - show_fiq_list(p, v); - seq_printf(p, "Err: %10lu\n", irq_err_count); - } -out: - return 0; -} - -/* - * IRQ lock detection. - * - * Hopefully, this should get us out of a few locked situations. - * However, it may take a while for this to happen, since we need - * a large number if IRQs to appear in the same jiffie with the - * same instruction pointer (or within 2 instructions). - */ -static int check_irq_lock(struct irqdesc *desc, int irq, struct pt_regs *regs) -{ - unsigned long instr_ptr = instruction_pointer(regs); - - if (desc->lck_jif == jiffies && - desc->lck_pc >= instr_ptr && desc->lck_pc < instr_ptr + 8) { - desc->lck_cnt += 1; - - if (desc->lck_cnt > MAX_IRQ_CNT) { - printk(KERN_ERR "IRQ LOCK: IRQ%d is locking the system, disabled\n", irq); - return 1; - } - } else { - desc->lck_cnt = 0; - desc->lck_pc = instruction_pointer(regs); - desc->lck_jif = jiffies; - } - return 0; -} - -static void -__do_irq(unsigned int irq, struct irqaction *action, struct pt_regs *regs) -{ - unsigned int status; - int ret; - - spin_unlock(&irq_controller_lock); - if (!(action->flags & IRQF_DISABLED)) - local_irq_enable(); - - status = 0; - do { - ret = action->handler(irq, action->dev_id, regs); - if (ret == IRQ_HANDLED) - status |= action->flags; - action = action->next; - } while (action); - - if (status & IRQF_SAMPLE_RANDOM) - add_interrupt_randomness(irq); - - spin_lock_irq(&irq_controller_lock); -} - -/* - * This is for software-decoded IRQs. The caller is expected to - * handle the ack, clear, mask and unmask issues. - */ -void -do_simple_IRQ(unsigned int irq, struct irqdesc *desc, struct pt_regs *regs) -{ - struct irqaction *action; - const int cpu = smp_processor_id(); - - desc->triggered = 1; - - kstat_cpu(cpu).irqs[irq]++; - - action = desc->action; - if (action) - __do_irq(irq, desc->action, regs); -} - -/* - * Most edge-triggered IRQ implementations seem to take a broken - * approach to this. Hence the complexity. - */ -void -do_edge_IRQ(unsigned int irq, struct irqdesc *desc, struct pt_regs *regs) -{ - const int cpu = smp_processor_id(); - - desc->triggered = 1; - - /* - * If we're currently running this IRQ, or its disabled, - * we shouldn't process the IRQ. Instead, turn on the - * hardware masks. - */ - if (unlikely(desc->running || !desc->enabled)) - goto running; - - /* - * Acknowledge and clear the IRQ, but don't mask it. - */ - desc->chip->ack(irq); - - /* - * Mark the IRQ currently in progress. - */ - desc->running = 1; - - kstat_cpu(cpu).irqs[irq]++; - - do { - struct irqaction *action; - - action = desc->action; - if (!action) - break; - - if (desc->pending && desc->enabled) { - desc->pending = 0; - desc->chip->unmask(irq); - } - - __do_irq(irq, action, regs); - } while (desc->pending); - - desc->running = 0; - - /* - * If we were disabled or freed, shut down the handler. - */ - if (likely(desc->action && !check_irq_lock(desc, irq, regs))) - return; - - running: - /* - * We got another IRQ while this one was masked or - * currently running. Delay it. - */ - desc->pending = 1; - desc->chip->mask(irq); - desc->chip->ack(irq); -} - -/* - * Level-based IRQ handler. Nice and simple. - */ -void -do_level_IRQ(unsigned int irq, struct irqdesc *desc, struct pt_regs *regs) -{ - struct irqaction *action; - const int cpu = smp_processor_id(); - - desc->triggered = 1; - - /* - * Acknowledge, clear _AND_ disable the interrupt. - */ - desc->chip->ack(irq); - - if (likely(desc->enabled)) { - kstat_cpu(cpu).irqs[irq]++; - - /* - * Return with this interrupt masked if no action - */ - action = desc->action; - if (action) { - __do_irq(irq, desc->action, regs); - - if (likely(desc->enabled && - !check_irq_lock(desc, irq, regs))) - desc->chip->unmask(irq); - } - } -} - -/* - * do_IRQ handles all hardware IRQ's. Decoded IRQs should not - * come via this function. Instead, they should provide their - * own 'handler' - */ -asmlinkage void asm_do_IRQ(int irq, struct pt_regs *regs) -{ - struct irqdesc *desc = irq_desc + irq; - - /* - * Some hardware gives randomly wrong interrupts. Rather - * than crashing, do something sensible. - */ - if (irq >= NR_IRQS) - desc = &bad_irq_desc; - - irq_enter(); - spin_lock(&irq_controller_lock); - desc->handle(irq, desc, regs); - spin_unlock(&irq_controller_lock); - irq_exit(); -} - -void __set_irq_handler(unsigned int irq, irq_handler_t handle, int is_chained) -{ - struct irqdesc *desc; - unsigned long flags; - - if (irq >= NR_IRQS) { - printk(KERN_ERR "Trying to install handler for IRQ%d\n", irq); - return; - } - - if (handle == NULL) - handle = do_bad_IRQ; - - desc = irq_desc + irq; - - if (is_chained && desc->chip == &bad_chip) - printk(KERN_WARNING "Trying to install chained handler for IRQ%d\n", irq); - - spin_lock_irqsave(&irq_controller_lock, flags); - if (handle == do_bad_IRQ) { - desc->chip->mask(irq); - desc->chip->ack(irq); - desc->depth = 1; - desc->enabled = 0; - } - desc->handle = handle; - if (handle != do_bad_IRQ && is_chained) { - desc->valid = 0; - desc->probe_ok = 0; - desc->depth = 0; - desc->chip->unmask(irq); - } - spin_unlock_irqrestore(&irq_controller_lock, flags); -} - -void set_irq_chip(unsigned int irq, struct irqchip *chip) -{ - struct irqdesc *desc; - unsigned long flags; - - if (irq >= NR_IRQS) { - printk(KERN_ERR "Trying to install chip for IRQ%d\n", irq); - return; - } - - if (chip == NULL) - chip = &bad_chip; - - desc = irq_desc + irq; - spin_lock_irqsave(&irq_controller_lock, flags); - desc->chip = chip; - spin_unlock_irqrestore(&irq_controller_lock, flags); -} - -int set_irq_type(unsigned int irq, unsigned int type) -{ - struct irqdesc *desc; - unsigned long flags; - int ret = -ENXIO; - - if (irq >= NR_IRQS) { - printk(KERN_ERR "Trying to set irq type for IRQ%d\n", irq); - return -ENODEV; - } - - desc = irq_desc + irq; - if (desc->chip->type) { - spin_lock_irqsave(&irq_controller_lock, flags); - ret = desc->chip->type(irq, type); - spin_unlock_irqrestore(&irq_controller_lock, flags); - } - - return ret; -} - -void set_irq_flags(unsigned int irq, unsigned int iflags) -{ - struct irqdesc *desc; - unsigned long flags; - - if (irq >= NR_IRQS) { - printk(KERN_ERR "Trying to set irq flags for IRQ%d\n", irq); - return; - } - - desc = irq_desc + irq; - spin_lock_irqsave(&irq_controller_lock, flags); - desc->valid = (iflags & IRQF_VALID) != 0; - desc->probe_ok = (iflags & IRQF_PROBE) != 0; - desc->noautoenable = (iflags & IRQF_NOAUTOEN) != 0; - spin_unlock_irqrestore(&irq_controller_lock, flags); -} - -int setup_irq(unsigned int irq, struct irqaction *new) -{ - int shared = 0; - struct irqaction *old, **p; - unsigned long flags; - struct irqdesc *desc; - - /* - * 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 & IRQF_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 - */ - desc = irq_desc + irq; - spin_lock_irqsave(&irq_controller_lock, flags); - p = &desc->action; - if ((old = *p) != NULL) { - /* Can't share interrupts unless both agree to */ - if (!(old->flags & new->flags & IRQF_SHARED)) { - spin_unlock_irqrestore(&irq_controller_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->probing = 0; - desc->running = 0; - desc->pending = 0; - desc->depth = 1; - if (!desc->noautoenable) { - desc->depth = 0; - desc->enabled = 1; - desc->chip->unmask(irq); - } - } - - spin_unlock_irqrestore(&irq_controller_lock, flags); - return 0; -} - -/** - * 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: - * - * IRQF_SHARED Interrupt is shared - * - * IRQF_DISABLED Disable local interrupts while processing - * - * IRQF_SAMPLE_RANDOM The interrupt can be used for entropy - * - */ - -//FIXME - handler used to return void - whats the significance of the change? -int request_irq(unsigned int irq, irqreturn_t (*handler)(int, void *, struct pt_regs *), - unsigned long irq_flags, const char * devname, void *dev_id) -{ - unsigned long retval; - struct irqaction *action; - - if (irq >= NR_IRQS || !irq_desc[irq].valid || !handler || - (irq_flags & IRQF_SHARED && !dev_id)) - return -EINVAL; - - action = kmalloc(sizeof(struct irqaction), GFP_KERNEL); - if (!action) - return -ENOMEM; - - action->handler = handler; - action->flags = irq_flags; - 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. - * - * This function may be called from interrupt context. - */ -void free_irq(unsigned int irq, void *dev_id) -{ - struct irqaction * action, **p; - unsigned long flags; - - if (irq >= NR_IRQS || !irq_desc[irq].valid) { - printk(KERN_ERR "Trying to free IRQ%d\n",irq); -#ifdef CONFIG_DEBUG_ERRORS - __backtrace(); -#endif - return; - } - - spin_lock_irqsave(&irq_controller_lock, flags); - for (p = &irq_desc[irq].action; (action = *p) != NULL; p = &action->next) { - if (action->dev_id != dev_id) - continue; - - /* Found it - now free it */ - *p = action->next; - kfree(action); - goto out; - } - printk(KERN_ERR "Trying to free free IRQ%d\n",irq); -#ifdef CONFIG_DEBUG_ERRORS - __backtrace(); -#endif -out: - spin_unlock_irqrestore(&irq_controller_lock, flags); -} - -EXPORT_SYMBOL(free_irq); - -/* Start the interrupt probing. Unlike other architectures, - * we don't return a mask of interrupts from probe_irq_on, - * but return the number of interrupts enabled for the probe. - * The interrupts which have been enabled for probing is - * instead recorded in the irq_desc structure. - */ -unsigned long probe_irq_on(void) -{ - unsigned int i, irqs = 0; - unsigned long delay; - - /* - * first snaffle up any unassigned but - * probe-able interrupts - */ - spin_lock_irq(&irq_controller_lock); - for (i = 0; i < NR_IRQS; i++) { - if (!irq_desc[i].probe_ok || irq_desc[i].action) - continue; - - irq_desc[i].probing = 1; - irq_desc[i].triggered = 0; - if (irq_desc[i].chip->type) - irq_desc[i].chip->type(i, IRQT_PROBE); - irq_desc[i].chip->unmask(i); - irqs += 1; - } - spin_unlock_irq(&irq_controller_lock); - - /* - * wait for spurious interrupts to mask themselves out again - */ - for (delay = jiffies + HZ/10; time_before(jiffies, delay); ) - /* min 100ms delay */; - - /* - * now filter out any obviously spurious interrupts - */ - spin_lock_irq(&irq_controller_lock); - for (i = 0; i < NR_IRQS; i++) { - if (irq_desc[i].probing && irq_desc[i].triggered) { - irq_desc[i].probing = 0; - irqs -= 1; - } - } - spin_unlock_irq(&irq_controller_lock); - - return irqs; -} - -EXPORT_SYMBOL(probe_irq_on); - -/* - * Possible return values: - * >= 0 - interrupt number - * -1 - no interrupt/many interrupts - */ -int probe_irq_off(unsigned long irqs) -{ - unsigned int i; - int irq_found = NO_IRQ; - - /* - * look at the interrupts, and find exactly one - * that we were probing has been triggered - */ - spin_lock_irq(&irq_controller_lock); - for (i = 0; i < NR_IRQS; i++) { - if (irq_desc[i].probing && - irq_desc[i].triggered) { - if (irq_found != NO_IRQ) { - irq_found = NO_IRQ; - goto out; - } - irq_found = i; - } - } - - if (irq_found == -1) - irq_found = NO_IRQ; -out: - spin_unlock_irq(&irq_controller_lock); - - return irq_found; -} - -EXPORT_SYMBOL(probe_irq_off); - -void __init init_irq_proc(void) -{ -} - -void __init init_IRQ(void) -{ - struct irqdesc *desc; - extern void init_dma(void); - int irq; - - for (irq = 0, desc = irq_desc; irq < NR_IRQS; irq++, desc++) - *desc = bad_irq_desc; - - arc_init_irq(); - init_dma(); -} |
