/* * linux/arch/i386/kernel/irq.c * * Copyright (C) 1992, 1998 Linus Torvalds, Ingo Molnar * * 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. */ /* * (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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* * Linux has a controller-independent x86 interrupt architecture. * every controller has a 'controller-template', that is used * by the main code to do the right thing. Each driver-visible * interrupt source is transparently wired to the apropriate * controller. Thus drivers need not be aware of the * interrupt-controller. * * Various interrupt controllers we handle: 8259 PIC, SMP IO-APIC, * PIIX4's internal 8259 PIC and SGI's Visual Workstation Cobalt (IO-)APIC. * (IO-APICs assumed to be messaging to Pentium local-APICs) * * the code is designed to be easily extended with new/different * interrupt controllers, without having to do assembly magic. */ /* * 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 } }; static void register_irq_proc (unsigned int irq); /* * per-CPU IRQ handling stacks */ #ifdef CONFIG_4KSTACKS union irq_ctx *hardirq_ctx[NR_CPUS]; union irq_ctx *softirq_ctx[NR_CPUS]; #endif /* * 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. */ #ifdef CONFIG_X86 printk("unexpected IRQ trap at vector %02x\n", irq); #ifdef CONFIG_X86_LOCAL_APIC /* * Currently unexpected vectors happen only on SMP and APIC. * We _must_ ack these because every local APIC has only N * irq slots per priority level, and a 'hanging, unacked' IRQ * holds up an irq slot - in excessive cases (when multiple * unexpected vectors occur) that might lock up the APIC * completely. */ ack_APIC_irq(); #endif #endif } /* 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 }; atomic_t irq_err_count; #if defined(CONFIG_X86_IO_APIC) && defined(APIC_MISMATCH_DEBUG) atomic_t irq_mis_count; #endif /* * Generic, controller-independent functions: */ int show_interrupts(struct seq_file *p, void *v) { int i = *(loff_t *) v, j; struct irqaction * action; unsigned long flags; if (i == 0) { seq_printf(p, " "); for (j=0; jtypename); 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[i].lock, flags); } else if (i == NR_IRQS) { seq_printf(p, "NMI: "); for (j = 0; j < NR_CPUS; j++) if (cpu_online(j)) seq_printf(p, "%10u ", nmi_count(j)); seq_putc(p, '\n'); #ifdef CONFIG_X86_LOCAL_APIC seq_printf(p, "LOC: "); for (j = 0; j < NR_CPUS; j++) if (cpu_online(j)) seq_printf(p, "%10u ", irq_stat[j].apic_timer_irqs); seq_putc(p, '\n'); #endif seq_printf(p, "ERR: %10u\n", atomic_read(&irq_err_count)); #if defined(CONFIG_X86_IO_APIC) && defined(APIC_MISMATCH_DEBUG) seq_printf(p, "MIS: %10u\n", atomic_read(&irq_mis_count)); #endif } 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. */ asmlinkage int handle_IRQ_event(unsigned int irq, struct pt_regs *regs, struct irqaction *action) { int status = 1; /* Force the "do bottom halves" bit */ int retval = 0; if (!(action->flags & SA_INTERRUPT)) local_irq_enable(); do { status |= action->flags; retval |= action->handler(irq, action->dev_id, regs); 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 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. */ inline void 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. 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) { irq_desc_t *desc = irq_desc + irq; disable_irq_nosync(irq); if (desc->action) synchronize_irq(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) { 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); } /* * do_IRQ handles all normal device IRQ's (the special * SMP cross-CPU interrupts have their own specific * handlers). */ asmlinkage unsigned int do_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 irq = regs.orig_eax & 0xff; /* high bits used in ret_from_ code */ irq_desc_t *desc = irq_desc + irq; struct irqaction * action; unsigned int status; irq_enter(); #ifdef CONFIG_DEBUG_STACKOVERFLOW /* Debugging check for stack overflow: is there less than 1KB free? */ { long esp; __asm__ __volatile__("andl %%esp,%0" : "=r" (esp) : "0" (THREAD_SIZE - 1)); if (unlikely(esp < (sizeof(struct thread_info) + STACK_WARN))) { printk("do_IRQ: stack overflow: %ld\n", esp - sizeof(struct thread_info)); dump_stack(); } } #endif 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. */ #ifdef CONFIG_4KSTACKS for (;;) { irqreturn_t action_ret; u32 *isp; union irq_ctx * curctx; union irq_ctx * irqctx; curctx = (union irq_ctx *) current_thread_info(); irqctx = hardirq_ctx[smp_processor_id()]; spin_unlock(&desc->lock); /* * this is where we switch to the IRQ stack. However, if we are already using * the IRQ stack (because we interrupted a hardirq handler) we can't do that * and just have to keep using the current stack (which is the irq stack already * after all) */ if (curctx == irqctx) action_ret = handle_IRQ_event(irq, ®s, action); else { /* build the stack frame on the IRQ stack */ isp = (u32*) ((char*)irqctx + sizeof(*irqctx)); irqctx->tinfo.task = curctx->tinfo.task; irqctx->tinfo.previous_esp = current_stack_pointer(); *--isp = (u32) action; *--isp = (u32) ®s; *--isp = (u32) irq; asm volatile( " xchgl %%ebx,%%esp \n" " call handle_IRQ_event \n" " xchgl %%ebx,%%esp \n" : "=a"(action_ret) : "b"(isp) : "memory", "cc", "edx", "ecx" ); } spin_lock(&desc->lock); if (!noirqdebug) note_interrupt(irq, desc, action_ret); if (curctx != irqctx) irqctx->tinfo.task = NULL; if (likely(!(desc->status & IRQ_PENDING))) break; desc->status &= ~IRQ_PENDING; } #else for (;;) { irqreturn_t action_ret; spin_unlock(&desc->lock); action_ret = handle_IRQ_event(irq, ®s, action); spin_lock(&desc->lock); if (!noirqdebug) note_interrupt(irq, desc, action_ret); if (likely(!(desc->status & IRQ_PENDING))) break; desc->status &= ~IRQ_PENDING; } #endif 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; } int can_request_irq(unsigned int irq, unsigned long irqflags) { struct irqaction *action; if (irq >= NR_IRQS) return 0; action = irq_desc[irq].action; if (action) { if (irqflags & action->flags & SA_SHIRQ) action = NULL; } return !action; } /** * 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_ATOMIC); if (!action) return -ENOMEM; action->handler = handler; action->flags = irqflags; action->mask = 0; 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 * 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; if (desc->handler == &no_irq_type) return -ENOSYS; /* * 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; } static struct proc_dir_entry * root_irq_dir; static struct proc_dir_entry * irq_dir [NR_IRQS]; #ifdef CONFIG_SMP static struct proc_dir_entry *smp_affinity_entry[NR_IRQS]; cpumask_t irq_affinity[NR_IRQS] = { [0 ... NR_IRQS-1] = CPU_MASK_ALL }; 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 __user *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); if (err) return err; /* * 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, cpumask_of_cpu(first_cpu(new_value))); return full_count; } #endif static int prof_cpu_mask_read_proc (char *page, char **start, off_t off, int count, int *eof, void *data) { int len = cpumask_scnprintf(page, count, *(cpumask_t *)data); if (count - len < 2) return -EINVAL; len += sprintf(page + len, "\n"); return len; } static int prof_cpu_mask_write_proc (struct file *file, const char __user *buffer, unsigned long count, void *data) { cpumask_t *mask = (cpumask_t *)data; unsigned long full_count = count, err; cpumask_t new_value; err = cpumask_parse(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_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; } #endif } 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); } #ifdef CONFIG_4KSTACKS static char softirq_stack[NR_CPUS * THREAD_SIZE] __attribute__((__aligned__(THREAD_SIZE))); static char hardirq_stack[NR_CPUS * THREAD_SIZE] __attribute__((__aligned__(THREAD_SIZE))); /* * allocate per-cpu stacks for hardirq and for softirq processing */ void irq_ctx_init(int cpu) { union irq_ctx *irqctx; if (hardirq_ctx[cpu]) return; irqctx = (union irq_ctx*) &hardirq_stack[cpu*THREAD_SIZE]; irqctx->tinfo.task = NULL; irqctx->tinfo.exec_domain = NULL; irqctx->tinfo.cpu = cpu; irqctx->tinfo.preempt_count = HARDIRQ_OFFSET; irqctx->tinfo.addr_limit = MAKE_MM_SEG(0); hardirq_ctx[cpu] = irqctx; irqctx = (union irq_ctx*) &softirq_stack[cpu*THREAD_SIZE]; irqctx->tinfo.task = NULL; irqctx->tinfo.exec_domain = NULL; irqctx->tinfo.cpu = cpu; irqctx->tinfo.preempt_count = SOFTIRQ_OFFSET; irqctx->tinfo.addr_limit = MAKE_MM_SEG(0); softirq_ctx[cpu] = irqctx; printk("CPU %u irqstacks, hard=%p soft=%p\n", cpu,hardirq_ctx[cpu],softirq_ctx[cpu]); } extern asmlinkage void __do_softirq(void); asmlinkage void do_softirq(void) { unsigned long flags; struct thread_info *curctx; union irq_ctx *irqctx; u32 *isp; if (in_interrupt()) return; local_irq_save(flags); if (local_softirq_pending()) { curctx = current_thread_info(); irqctx = softirq_ctx[smp_processor_id()]; irqctx->tinfo.task = curctx->task; irqctx->tinfo.previous_esp = current_stack_pointer(); /* build the stack frame on the softirq stack */ isp = (u32*) ((char*)irqctx + sizeof(*irqctx)); asm volatile( " xchgl %%ebx,%%esp \n" " call __do_softirq \n" " movl %%ebx,%%esp \n" : "=b"(isp) : "0"(isp) : "memory", "cc", "edx", "ecx", "eax" ); } local_irq_restore(flags); } EXPORT_SYMBOL(do_softirq); #endif