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Hi all,
attached patch is a second try of IRQ handling code consolidation.
This is a x86_64 specific patch (untested).
Best regards.
-- Andrey Panin | Embedded systems software developer pazke@orbita1.ru | PGP key: wwwkeys.pgp.net--=_courier-2655-1041682047-0001-2 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: attachment; filename="patch-irq-x86_64-2.5.53"
diff --minimal -urN -X /usr/share/dontdiff linux-2.5.53.vanilla/arch/x86_64/Kconfig linux-2.5.53/arch/x86_64/Kconfig --- linux-2.5.53.vanilla/arch/x86_64/Kconfig Fri Dec 27 19:45:05 2002 +++ linux-2.5.53/arch/x86_64/Kconfig Sat Jan 4 13:47:05 2003 @@ -33,6 +33,10 @@ bool default y +config GENERIC_IRQ + bool + default y + config ISA bool help diff --minimal -urN -X /usr/share/dontdiff linux-2.5.53.vanilla/arch/x86_64/kernel/irq.c linux-2.5.53/arch/x86_64/kernel/irq.c --- linux-2.5.53.vanilla/arch/x86_64/kernel/irq.c Fri Dec 27 19:45:02 2002 +++ linux-2.5.53/arch/x86_64/kernel/irq.c Sat Jan 4 13:45:55 2003 @@ -2,20 +2,8 @@ * linux/arch/x86_64/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 <linux/config.h> #include <linux/errno.h> @@ -62,65 +50,9 @@ * 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] = { 0, &no_irq_type, NULL, 0, SPIN_LOCK_UNLOCKED}}; static void register_irq_proc (unsigned int irq); -/* - * Special irq handlers. - */ - -void no_action(int cpl, void *dev_id, struct pt_regs *regs) { } - -/* - * 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 doesnt deserve - * a generic callback i think. - */ -#if 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; #ifdef CONFIG_X86_IO_APIC #ifdef APIC_MISMATCH_DEBUG atomic_t irq_mis_count; @@ -179,129 +111,6 @@ 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 */ - - if (!(action->flags & SA_INTERRUPT)) - local_irq_enable(); - - do { - status |= action->flags; - 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 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 and Enables are - * nested. - * Unlike disable_irq(), this function does not ensure existing - * instances of the IRQ handler have completed before returning. - * - * This function must not 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) -{ - disable_irq_nosync(irq); - 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 @@ -392,429 +201,10 @@ 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, - void (*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; -} - -/** - * 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; - } -} - -/* - * 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; -} - -/* - * 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; -} - -/* 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); - 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]; #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; -} #if CONFIG_SMP diff --minimal -urN -X /usr/share/dontdiff linux-2.5.53.vanilla/include/asm-x86_64/hw_irq.h linux-2.5.53/include/asm-x86_64/hw_irq.h --- linux-2.5.53.vanilla/include/asm-x86_64/hw_irq.h Fri Dec 27 19:47:09 2002 +++ linux-2.5.53/include/asm-x86_64/hw_irq.h Sat Jan 4 13:49:51 2003 @@ -182,4 +182,31 @@ #endif +/* + * 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. + */ +#ifdef CONFIG_X86_LOCAL_APIC +#define arch_ack_bad_irq(irq) ack_APIC_irq() +#else +#define arch_ack_bad_irq(irq) do { } while (0) +#endif + +/* Return a pointer to the irq descriptor for IRQ. */ +#define irq_desc(irq) (irq_desc + (irq)) + +/* Check irq number */ +#define arch_check_irq(irq) ((irq) >= NR_IRQS) + +/* Arch specific hook for setup_irq() */ +#define arch_setup_irq(irq, desc, irqaction) do { } while (0) + +/* Used in setup_irq() */ +#define ARCH_NONSHARED_IRQ_MASK \ + ~(IRQ_DISABLED | IRQ_AUTODETECT | IRQ_WAITING) + #endif /* _ASM_HW_IRQ_H */
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