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Hi all,
attached patch is a second try of IRQ handling code consolidation.
This is a common part (tested and works on i386).
Best regards.
-- Andrey Panin | Embedded systems software developer pazke@orbita1.ru | PGP key: wwwkeys.pgp.net--=_courier-430-1041681222-0001-2 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: attachment; filename="patch-irq-common-2.5.53"
diff --minimal -urN -X /usr/share/dontdiff linux-2.5.53.vanilla/kernel/Makefile linux-2.5.53/kernel/Makefile --- linux-2.5.53.vanilla/kernel/Makefile Fri Dec 27 19:48:22 2002 +++ linux-2.5.53/kernel/Makefile Mon Dec 30 14:46:27 2002 @@ -22,6 +22,7 @@ obj-$(CONFIG_BSD_PROCESS_ACCT) += acct.o obj-$(CONFIG_SOFTWARE_SUSPEND) += suspend.o obj-$(CONFIG_COMPAT) += compat.o +obj-$(CONFIG_GENERIC_IRQ) += irq.o ifneq ($(CONFIG_IA64),y) # According to Alan Modra <alan@linuxcare.com.au>, the -fno-omit-frame-pointer is diff --minimal -urN -X /usr/share/dontdiff linux-2.5.53.vanilla/kernel/irq.c linux-2.5.53/kernel/irq.c --- linux-2.5.53.vanilla/kernel/irq.c Thu Jan 1 03:00:00 1970 +++ linux-2.5.53/kernel/irq.c Fri Jan 3 23:28:05 2003 @@ -0,0 +1,670 @@ +/* + * linux/kernel/irq.c + * + * Architecture independent parts of IRQ handling. + * + * Copyright (C) 1992-2002 Linus Torvalds. + * + * Modified from the alpha version by Andrey Panin. + * + * 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. + * + * 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. + * + * 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. + * + * The code is designed to be easily extended with new/different + * interrupt controllers, without having to do assembly magic. + */ + +#include <linux/config.h> +#include <linux/slab.h> +#include <linux/errno.h> +#include <linux/signal.h> +#include <linux/irq.h> +#include <linux/interrupt.h> +#include <linux/random.h> +#include <linux/jiffies.h> + +#include <asm/param.h> +#include <asm/semaphore.h> +#include <asm/hw_irq.h> +#include <asm/uaccess.h> + +#ifndef HAVE_ARCH_IRQ_DESC + +/* + * 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, + } +}; + +#endif + +/* + * Special irq handlers. + */ + +void no_action(int cpl, void *dev_id, struct pt_regs *regs) { } + +/* + * Generic no controller code + */ +atomic_t irq_err_count; + +static void no_irq_enable_disable(unsigned int irq) { } +static unsigned int no_irq_startup(unsigned int irq) { return 0; } + +static void no_irq_ack(unsigned int irq) +{ + atomic_inc(&irq_err_count); + printk(KERN_CRIT "Unexpected IRQ trap at vector %u\n", irq); + arch_ack_bad_irq(irq); +} + +struct hw_interrupt_type no_irq_type = { + .typename = "none", + .startup = no_irq_startup, + .shutdown = no_irq_enable_disable, + .enable = no_irq_enable_disable, + .disable = no_irq_enable_disable, + .ack = no_irq_ack, + .end = no_irq_enable_disable, +}; + +/* + * 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; +} + +#if defined(CONFIG_SMP) && !defined(HAVE_ARCH_SYNCRONIZE_IRQ) + +inline void synchronize_irq(unsigned int irq) +{ + irq_desc_t *desc = irq_desc(irq); + + /* is there anything to synchronize with? */ + if (!desc->action) + return; + + while (desc->status & IRQ_INPROGRESS) + cpu_relax(); +} + +#endif + +/* + * Workarounds for interrupt types without disable() (on ppc & ppc64). + * Will be removed some day. + */ + +static int startup_irq(unsigned int irq) +{ + irq_desc_t *desc = irq_desc(irq); + + if (desc->handler->startup) + return desc->handler->startup(irq); + else if (desc->handler->enable) + desc->handler->enable(irq); + else + BUG(); + return 0; +} + +static void shutdown_irq(unsigned int irq) +{ + irq_desc_t *desc = irq_desc(irq); + + if (desc->handler->shutdown) + desc->handler->shutdown(irq); + else if (desc->handler->disable) + desc->handler->disable(irq); + else + BUG(); +} + +/* + * 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++) { + /* Needed for ppc & ppc64, doesn't harm others (really ?) */ + if (!(desc->status & IRQ_PER_CPU)) + 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. 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 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(KERN_ERR "enable_irq(%u) unbalanced from %p\n", + irq, __builtin_return_address(0)); + } + spin_unlock_irqrestore(&desc->lock, flags); +} + +/** + * 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; + + /* + * 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(KERN_ERR "Bad boy: %s (at %p) called us " \ + "without a dev_id!\n", devname, + __builtin_return_address(0)); + } + + if (arch_check_irq(irq) || !handler) + return -EINVAL; + + action = 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; +} + +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); + } + + arch_setup_irq(irq, desc, new); + + /* + * 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 &= ARCH_NONSHARED_IRQ_MASK; + startup_irq(irq); + } + spin_unlock_irqrestore(&desc->lock, flags); + +// arch_register_irq_proc(irq); + + return 0; +} + +/** + * 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 (arch_check_irq(irq)) { + printk(KERN_CRIT "Trying to free IRQ%d\n", irq); + 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; + shutdown_irq(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(KERN_CRIT "Trying to free free IRQ%d\n", irq); + spin_unlock_irqrestore(&desc->lock, flags); + return; + } +} + +#ifndef HAVE_ARCH_IRQ_PROBE + +/* + * 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 (!desc->action) + startup_irq(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 (startup_irq(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; + shutdown_irq(i); + } else + if (i < 32) + val |= 1 << i; + } + spin_unlock_irq(&desc->lock); + } + + return val; +} + +/** + * 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. This function can handle only + * legacy ISA interrupts + * + * 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; + shutdown_irq(i); + } + spin_unlock_irq(&desc->lock); + } + up(&probe_sem); + + return mask & val; +} + +/** + * 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. This function can handle any interrupt source. + * + * 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; + shutdown_irq(i); + } + spin_unlock_irq(&desc->lock); + } + up(&probe_sem); + + if (nr_irqs > 1) + irq_found = -irq_found; + return irq_found; +} + +#endif /* HAVE_ARCH_IRQ_PROBE */ + +#ifndef HAVE_ARCH_IRQ_PROC + +#ifndef ARCH_PROC_SMP_AFF_WIDTH +#define ARCH_PROC_SMP_AFF_WIDTH 8 +#endif + +unsigned int parse_hex_value(const char *buffer, unsigned long count, + unsigned long *ret) +{ + unsigned char hexnum[ARCH_PROC_SMP_AFF_WIDTH]; + unsigned long value, i; + + if (!count) + return -EINVAL; + if (count > ARCH_PROC_SMP_AFF_WIDTH) + count = ARCH_PROC_SMP_AFF_WIDTH; + if (copy_from_user(hexnum, buffer, count)) + return -EFAULT; + + /* + * Parse the first ARCH_PROC_SMP_AFF_WIDTH 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; +} + +#endif /* HAVE_ARCH_IRQ_PROC */
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