diff options
Diffstat (limited to 'arch/blackfin/kernel/irqchip.c')
| -rw-r--r-- | arch/blackfin/kernel/irqchip.c | 153 |
1 files changed, 153 insertions, 0 deletions
diff --git a/arch/blackfin/kernel/irqchip.c b/arch/blackfin/kernel/irqchip.c new file mode 100644 index 00000000..ff3d7471 --- /dev/null +++ b/arch/blackfin/kernel/irqchip.c @@ -0,0 +1,153 @@ +/* + * Copyright 2005-2009 Analog Devices Inc. + * + * Licensed under the GPL-2 or later + */ + +#include <linux/kernel_stat.h> +#include <linux/module.h> +#include <linux/random.h> +#include <linux/seq_file.h> +#include <linux/kallsyms.h> +#include <linux/interrupt.h> +#include <linux/irq.h> +#include <asm/irq_handler.h> +#include <asm/trace.h> +#include <asm/pda.h> + +static atomic_t irq_err_count; +void ack_bad_irq(unsigned int irq) +{ + atomic_inc(&irq_err_count); + printk(KERN_ERR "IRQ: spurious interrupt %d\n", irq); +} + +static struct irq_desc bad_irq_desc = { + .handle_irq = handle_bad_irq, + .lock = __RAW_SPIN_LOCK_UNLOCKED(bad_irq_desc.lock), +}; + +#ifdef CONFIG_CPUMASK_OFFSTACK +/* We are not allocating a variable-sized bad_irq_desc.affinity */ +#error "Blackfin architecture does not support CONFIG_CPUMASK_OFFSTACK." +#endif + +#ifdef CONFIG_PROC_FS +int show_interrupts(struct seq_file *p, void *v) +{ + int i = *(loff_t *) v, j; + struct irqaction *action; + unsigned long flags; + + if (i < NR_IRQS) { + struct irq_desc *desc = irq_to_desc(i); + + raw_spin_lock_irqsave(&desc->lock, flags); + action = desc->action; + if (!action) + goto skip; + seq_printf(p, "%3d: ", i); + for_each_online_cpu(j) + seq_printf(p, "%10u ", kstat_irqs_cpu(i, j)); + seq_printf(p, " %8s", irq_desc_get_chip(desc)->name); + 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: + raw_spin_unlock_irqrestore(&desc->lock, flags); + } else if (i == NR_IRQS) { + seq_printf(p, "NMI: "); + for_each_online_cpu(j) + seq_printf(p, "%10u ", cpu_pda[j].__nmi_count); + seq_printf(p, " CORE Non Maskable Interrupt\n"); + seq_printf(p, "Err: %10u\n", atomic_read(&irq_err_count)); + } + return 0; +} +#endif + +#ifdef CONFIG_DEBUG_STACKOVERFLOW +static void check_stack_overflow(int irq) +{ + /* Debugging check for stack overflow: is there less than STACK_WARN free? */ + long sp = __get_SP() & (THREAD_SIZE - 1); + + if (unlikely(sp < (sizeof(struct thread_info) + STACK_WARN))) { + dump_stack(); + pr_emerg("irq%i: possible stack overflow only %ld bytes free\n", + irq, sp - sizeof(struct thread_info)); + } +} +#else +static inline void check_stack_overflow(int irq) { } +#endif + +#ifndef CONFIG_IPIPE +static void maybe_lower_to_irq14(void) +{ + unsigned short pending, other_ints; + + /* + * If we're the only interrupt running (ignoring IRQ15 which + * is for syscalls), lower our priority to IRQ14 so that + * softirqs run at that level. If there's another, + * lower-level interrupt, irq_exit will defer softirqs to + * that. If the interrupt pipeline is enabled, we are already + * running at IRQ14 priority, so we don't need this code. + */ + CSYNC(); + pending = bfin_read_IPEND() & ~0x8000; + other_ints = pending & (pending - 1); + if (other_ints == 0) + lower_to_irq14(); +} +#else +static inline void maybe_lower_to_irq14(void) { } +#endif + +/* + * do_IRQ handles all hardware IRQs. Decoded IRQs should not + * come via this function. Instead, they should provide their + * own 'handler' + */ +#ifdef CONFIG_DO_IRQ_L1 +__attribute__((l1_text)) +#endif +asmlinkage void asm_do_IRQ(unsigned int irq, struct pt_regs *regs) +{ + struct pt_regs *old_regs = set_irq_regs(regs); + + irq_enter(); + + check_stack_overflow(irq); + + /* + * Some hardware gives randomly wrong interrupts. Rather + * than crashing, do something sensible. + */ + if (irq >= NR_IRQS) + handle_bad_irq(irq, &bad_irq_desc); + else + generic_handle_irq(irq); + + maybe_lower_to_irq14(); + + irq_exit(); + + set_irq_regs(old_regs); +} + +void __init init_IRQ(void) +{ + init_arch_irq(); + +#ifdef CONFIG_DEBUG_BFIN_HWTRACE_EXPAND + /* Now that evt_ivhw is set up, turn this on */ + trace_buff_offset = 0; + bfin_write_TBUFCTL(BFIN_TRACE_ON); + printk(KERN_INFO "Hardware Trace expanded to %ik\n", + 1 << CONFIG_DEBUG_BFIN_HWTRACE_EXPAND_LEN); +#endif +} |