2 * Copyright 2005-2009 Analog Devices Inc.
4 * Licensed under the GPL-2 or later
7 #include <linux/kernel_stat.h>
8 #include <linux/module.h>
9 #include <linux/random.h>
10 #include <linux/seq_file.h>
11 #include <linux/kallsyms.h>
12 #include <linux/interrupt.h>
13 #include <linux/irq.h>
14 #include <asm/trace.h>
17 static atomic_t irq_err_count;
18 void ack_bad_irq(unsigned int irq)
20 atomic_inc(&irq_err_count);
21 printk(KERN_ERR "IRQ: spurious interrupt %d\n", irq);
24 static struct irq_desc bad_irq_desc = {
25 .handle_irq = handle_bad_irq,
26 .lock = __RAW_SPIN_LOCK_UNLOCKED(bad_irq_desc.lock),
29 #ifdef CONFIG_CPUMASK_OFFSTACK
30 /* We are not allocating a variable-sized bad_irq_desc.affinity */
31 #error "Blackfin architecture does not support CONFIG_CPUMASK_OFFSTACK."
35 int show_interrupts(struct seq_file *p, void *v)
37 int i = *(loff_t *) v, j;
38 struct irqaction *action;
42 struct irq_desc *desc = irq_to_desc(i);
44 raw_spin_lock_irqsave(&desc->lock, flags);
45 action = desc->action;
48 seq_printf(p, "%3d: ", i);
49 for_each_online_cpu(j)
50 seq_printf(p, "%10u ", kstat_irqs_cpu(i, j));
51 seq_printf(p, " %8s", get_irq_desc_chip(desc)->name);
52 seq_printf(p, " %s", action->name);
53 for (action = action->next; action; action = action->next)
54 seq_printf(p, " %s", action->name);
58 raw_spin_unlock_irqrestore(&desc->lock, flags);
59 } else if (i == NR_IRQS) {
60 seq_printf(p, "NMI: ");
61 for_each_online_cpu(j)
62 seq_printf(p, "%10u ", cpu_pda[j].__nmi_count);
63 seq_printf(p, " CORE Non Maskable Interrupt\n");
64 seq_printf(p, "Err: %10u\n", atomic_read(&irq_err_count));
70 #ifdef CONFIG_DEBUG_STACKOVERFLOW
71 static void check_stack_overflow(int irq)
73 /* Debugging check for stack overflow: is there less than STACK_WARN free? */
74 long sp = __get_SP() & (THREAD_SIZE - 1);
76 if (unlikely(sp < (sizeof(struct thread_info) + STACK_WARN))) {
78 pr_emerg("irq%i: possible stack overflow only %ld bytes free\n",
79 irq, sp - sizeof(struct thread_info));
83 static inline void check_stack_overflow(int irq) { }
87 static void maybe_lower_to_irq14(void)
89 unsigned short pending, other_ints;
92 * If we're the only interrupt running (ignoring IRQ15 which
93 * is for syscalls), lower our priority to IRQ14 so that
94 * softirqs run at that level. If there's another,
95 * lower-level interrupt, irq_exit will defer softirqs to
96 * that. If the interrupt pipeline is enabled, we are already
97 * running at IRQ14 priority, so we don't need this code.
100 pending = bfin_read_IPEND() & ~0x8000;
101 other_ints = pending & (pending - 1);
106 static inline void maybe_lower_to_irq14(void) { }
110 * do_IRQ handles all hardware IRQs. Decoded IRQs should not
111 * come via this function. Instead, they should provide their
114 #ifdef CONFIG_DO_IRQ_L1
115 __attribute__((l1_text))
117 asmlinkage void asm_do_IRQ(unsigned int irq, struct pt_regs *regs)
119 struct pt_regs *old_regs = set_irq_regs(regs);
123 check_stack_overflow(irq);
126 * Some hardware gives randomly wrong interrupts. Rather
127 * than crashing, do something sensible.
130 handle_bad_irq(irq, &bad_irq_desc);
132 generic_handle_irq(irq);
134 maybe_lower_to_irq14();
138 set_irq_regs(old_regs);
141 void __init init_IRQ(void)
145 #ifdef CONFIG_DEBUG_BFIN_HWTRACE_EXPAND
146 /* Now that evt_ivhw is set up, turn this on */
147 trace_buff_offset = 0;
148 bfin_write_TBUFCTL(BFIN_TRACE_ON);
149 printk(KERN_INFO "Hardware Trace expanded to %ik\n",
150 1 << CONFIG_DEBUG_BFIN_HWTRACE_EXPAND_LEN);