diff options
Diffstat (limited to 'arch/frv/kernel/irq.c')
| -rw-r--r-- | arch/frv/kernel/irq.c | 764 |
1 files changed, 764 insertions, 0 deletions
diff --git a/arch/frv/kernel/irq.c b/arch/frv/kernel/irq.c new file mode 100644 index 0000000..8c524cd --- /dev/null +++ b/arch/frv/kernel/irq.c @@ -0,0 +1,764 @@ +/* irq.c: FRV IRQ handling + * + * Copyright (C) 2003, 2004 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ + +/* + * (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/ptrace.h> +#include <linux/errno.h> +#include <linux/signal.h> +#include <linux/sched.h> +#include <linux/ioport.h> +#include <linux/interrupt.h> +#include <linux/timex.h> +#include <linux/slab.h> +#include <linux/random.h> +#include <linux/smp_lock.h> +#include <linux/init.h> +#include <linux/kernel_stat.h> +#include <linux/irq.h> +#include <linux/proc_fs.h> +#include <linux/seq_file.h> + +#include <asm/atomic.h> +#include <asm/io.h> +#include <asm/smp.h> +#include <asm/system.h> +#include <asm/bitops.h> +#include <asm/uaccess.h> +#include <asm/pgalloc.h> +#include <asm/delay.h> +#include <asm/irq.h> +#include <asm/irc-regs.h> +#include <asm/irq-routing.h> +#include <asm/gdb-stub.h> + +extern void __init fpga_init(void); +extern void __init route_mb93493_irqs(void); + +static void register_irq_proc (unsigned int irq); + +/* + * Special irq handlers. + */ + +irqreturn_t no_action(int cpl, void *dev_id, struct pt_regs *regs) { return IRQ_HANDLED; } + +atomic_t irq_err_count; + +/* + * Generic, controller-independent functions: + */ +int show_interrupts(struct seq_file *p, void *v) +{ + struct irqaction *action; + struct irq_group *group; + unsigned long flags; + int level, grp, ix, i, j; + + i = *(loff_t *) v; + + switch (i) { + case 0: + seq_printf(p, " "); + for (j = 0; j < NR_CPUS; j++) + if (cpu_online(j)) + seq_printf(p, "CPU%d ",j); + + seq_putc(p, '\n'); + break; + + case 1 ... NR_IRQ_GROUPS * NR_IRQ_ACTIONS_PER_GROUP: + local_irq_save(flags); + + grp = (i - 1) / NR_IRQ_ACTIONS_PER_GROUP; + group = irq_groups[grp]; + if (!group) + goto skip; + + ix = (i - 1) % NR_IRQ_ACTIONS_PER_GROUP; + action = group->actions[ix]; + if (!action) + goto skip; + + seq_printf(p, "%3d: ", i - 1); + +#ifndef CONFIG_SMP + seq_printf(p, "%10u ", kstat_irqs(i)); +#else + for (j = 0; j < NR_CPUS; j++) + if (cpu_online(j)) + seq_printf(p, "%10u ", kstat_cpu(j).irqs[i - 1]); +#endif + + level = group->sources[ix]->level - frv_irq_levels; + + seq_printf(p, " %12s@%x", group->sources[ix]->muxname, level); + 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: + local_irq_restore(flags); + break; + + case NR_IRQ_GROUPS * NR_IRQ_ACTIONS_PER_GROUP + 1: + seq_printf(p, "ERR: %10u\n", atomic_read(&irq_err_count)); + break; + + default: + break; + } + + return 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. + */ + +void disable_irq_nosync(unsigned int irq) +{ + struct irq_source *source; + struct irq_group *group; + struct irq_level *level; + unsigned long flags; + int idx = irq & (NR_IRQ_ACTIONS_PER_GROUP - 1); + + group = irq_groups[irq >> NR_IRQ_LOG2_ACTIONS_PER_GROUP]; + if (!group) + BUG(); + + source = group->sources[idx]; + if (!source) + BUG(); + + level = source->level; + + spin_lock_irqsave(&level->lock, flags); + + if (group->control) { + if (!group->disable_cnt[idx]++) + group->control(group, idx, 0); + } else if (!level->disable_count++) { + __set_MASK(level - frv_irq_levels); + } + + spin_unlock_irqrestore(&level->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); + +#ifdef CONFIG_SMP + if (!local_irq_count(smp_processor_id())) { + do { + barrier(); + } while (irq_desc[irq].status & IRQ_INPROGRESS); + } +#endif +} + +/** + * 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) +{ + struct irq_source *source; + struct irq_group *group; + struct irq_level *level; + unsigned long flags; + int idx = irq & (NR_IRQ_ACTIONS_PER_GROUP - 1); + int count; + + group = irq_groups[irq >> NR_IRQ_LOG2_ACTIONS_PER_GROUP]; + if (!group) + BUG(); + + source = group->sources[idx]; + if (!source) + BUG(); + + level = source->level; + + spin_lock_irqsave(&level->lock, flags); + + if (group->control) + count = group->disable_cnt[idx]; + else + count = level->disable_count; + + switch (count) { + case 1: + if (group->control) { + if (group->actions[idx]) + group->control(group, idx, 1); + } else { + if (level->usage) + __clr_MASK(level - frv_irq_levels); + } + /* fall-through */ + + default: + count--; + break; + + case 0: + printk("enable_irq(%u) unbalanced from %p\n", irq, __builtin_return_address(0)); + } + + if (group->control) + group->disable_cnt[idx] = count; + else + level->disable_count = count; + + spin_unlock_irqrestore(&level->lock, flags); +} + +/*****************************************************************************/ +/* + * handles all normal device IRQ's + * - registers are referred to by the __frame variable (GR28) + * - IRQ distribution is complicated in this arch because of the many PICs, the + * way they work and the way they cascade + */ +asmlinkage void do_IRQ(void) +{ + struct irq_source *source; + int level, cpu; + + level = (__frame->tbr >> 4) & 0xf; + cpu = smp_processor_id(); + +#if 0 + { + static u32 irqcount; + *(volatile u32 *) 0xe1200004 = ~((irqcount++ << 8) | level); + *(volatile u16 *) 0xffc00100 = (u16) ~0x9999; + mb(); + } +#endif + + if ((unsigned long) __frame - (unsigned long) (current + 1) < 512) + BUG(); + + __set_MASK(level); + __clr_RC(level); + __clr_IRL(); + + kstat_this_cpu.irqs[level]++; + + irq_enter(); + + for (source = frv_irq_levels[level].sources; source; source = source->next) + source->doirq(source); + + irq_exit(); + + __clr_MASK(level); + + /* only process softirqs if we didn't interrupt another interrupt handler */ + if ((__frame->psr & PSR_PIL) == PSR_PIL_0) + if (local_softirq_pending()) + do_softirq(); + +#ifdef CONFIG_PREEMPT + local_irq_disable(); + while (--current->preempt_count == 0) { + if (!(__frame->psr & PSR_S) || + current->need_resched == 0 || + in_interrupt()) + break; + current->preempt_count++; + local_irq_enable(); + preempt_schedule(); + local_irq_disable(); + } +#endif + +#if 0 + { + *(volatile u16 *) 0xffc00100 = (u16) ~0x6666; + mb(); + } +#endif + +} /* end do_IRQ() */ + +/*****************************************************************************/ +/* + * handles all NMIs when not co-opted by the debugger + * - registers are referred to by the __frame variable (GR28) + */ +asmlinkage void do_NMI(void) +{ +} /* end do_NMI() */ + +/*****************************************************************************/ +/** + * 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_IRQ_LOG2_ACTIONS_PER_GROUP) >= NR_IRQ_GROUPS) + 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; + action->mask = CPU_MASK_NONE; + 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) +{ + struct irq_source *source; + struct irq_group *group; + struct irq_level *level; + struct irqaction **p, **pp; + unsigned long flags; + + if ((irq >> NR_IRQ_LOG2_ACTIONS_PER_GROUP) >= NR_IRQ_GROUPS) + return; + + group = irq_groups[irq >> NR_IRQ_LOG2_ACTIONS_PER_GROUP]; + if (!group) + BUG(); + + source = group->sources[irq & (NR_IRQ_ACTIONS_PER_GROUP - 1)]; + if (!source) + BUG(); + + level = source->level; + p = &group->actions[irq & (NR_IRQ_ACTIONS_PER_GROUP - 1)]; + + spin_lock_irqsave(&level->lock, flags); + + for (pp = p; *pp; pp = &(*pp)->next) { + struct irqaction *action = *pp; + + if (action->dev_id != dev_id) + continue; + + /* found it - remove from the list of entries */ + *pp = action->next; + + level->usage--; + + if (p == pp && group->control) + group->control(group, irq & (NR_IRQ_ACTIONS_PER_GROUP - 1), 0); + + if (level->usage == 0) + __set_MASK(level - frv_irq_levels); + + spin_unlock_irqrestore(&level->lock,flags); + +#ifdef CONFIG_SMP + /* Wait to make sure it's not being used on another CPU */ + while (desc->status & IRQ_INPROGRESS) + barrier(); +#endif + kfree(action); + return; + } +} + +/* + * IRQ autodetection code.. + * + * This depends on the fact that any interrupt that comes in on to an + * unassigned IRQ will cause GxICR_DETECT to be set + */ + +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) +{ + down(&probe_sem); + return 0; +} + +/* + * 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 xmask) +{ + up(&probe_sem); + return 0; +} + +/* + * Return the one interrupt that triggered (this can + * handle any interrupt source). + */ + +/** + * probe_irq_off - end an interrupt autodetect + * @xmask: 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 xmask) +{ + up(&probe_sem); + return -1; +} + +/* this was setup_x86_irq but it seems pretty generic */ +int setup_irq(unsigned int irq, struct irqaction *new) +{ + struct irq_source *source; + struct irq_group *group; + struct irq_level *level; + struct irqaction **p, **pp; + unsigned long flags; + + group = irq_groups[irq >> NR_IRQ_LOG2_ACTIONS_PER_GROUP]; + if (!group) + BUG(); + + source = group->sources[irq & (NR_IRQ_ACTIONS_PER_GROUP - 1)]; + if (!source) + BUG(); + + level = source->level; + + p = &group->actions[irq & (NR_IRQ_ACTIONS_PER_GROUP - 1)]; + + /* + * 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); + } + + /* must juggle the interrupt processing stuff with interrupts disabled */ + spin_lock_irqsave(&level->lock, flags); + + /* can't share interrupts unless all parties agree to */ + if (level->usage != 0 && !(level->flags & new->flags & SA_SHIRQ)) { + spin_unlock_irqrestore(&level->lock,flags); + return -EBUSY; + } + + /* add new interrupt at end of irq queue */ + pp = p; + while (*pp) + pp = &(*pp)->next; + + *pp = new; + + level->usage++; + level->flags = new->flags; + + /* turn the interrupts on */ + if (level->usage == 1) + __clr_MASK(level - frv_irq_levels); + + if (p == pp && group->control) + group->control(group, irq & (NR_IRQ_ACTIONS_PER_GROUP - 1), 1); + + spin_unlock_irqrestore(&level->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; +} + + +static int prof_cpu_mask_read_proc (char *page, char **start, off_t off, + int count, int *eof, void *data) +{ + unsigned long *mask = (unsigned long *) data; + if (count < HEX_DIGITS+1) + return -EINVAL; + return sprintf (page, "%08lx\n", *mask); +} + +static int prof_cpu_mask_write_proc (struct file *file, const char *buffer, + unsigned long count, void *data) +{ + unsigned long *mask = (unsigned long *) data, full_count = count, err; + unsigned long new_value; + + show_state(); + err = parse_hex_value(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_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); +} + +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); +} + +/*****************************************************************************/ +/* + * initialise the interrupt system + */ +void __init init_IRQ(void) +{ + route_cpu_irqs(); + fpga_init(); +#ifdef CONFIG_FUJITSU_MB93493 + route_mb93493_irqs(); +#endif +} /* end init_IRQ() */ |