2 * File: arch/blackfin/kernel/irqchip.c
7 * Description: This file contains the simple DMA Implementation for Blackfin
10 * Copyright 2004-2006 Analog Devices Inc.
12 * Bugs: Enter bugs at http://blackfin.uclinux.org/
14 * This program is free software; you can redistribute it and/or modify
15 * it under the terms of the GNU General Public License as published by
16 * the Free Software Foundation; either version 2 of the License, or
17 * (at your option) any later version.
19 * This program is distributed in the hope that it will be useful,
20 * but WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
22 * GNU General Public License for more details.
24 * You should have received a copy of the GNU General Public License
25 * along with this program; if not, see the file COPYING, or write
26 * to the Free Software Foundation, Inc.,
27 * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
30 #include <linux/kernel_stat.h>
31 #include <linux/module.h>
32 #include <linux/random.h>
33 #include <linux/seq_file.h>
34 #include <linux/kallsyms.h>
35 #include <linux/interrupt.h>
36 #include <linux/irq.h>
37 #include <asm/trace.h>
40 static atomic_t irq_err_count;
41 void ack_bad_irq(unsigned int irq)
43 atomic_inc(&irq_err_count);
44 printk(KERN_ERR "IRQ: spurious interrupt %d\n", irq);
47 static struct irq_desc bad_irq_desc = {
48 .handle_irq = handle_bad_irq,
49 .lock = __SPIN_LOCK_UNLOCKED(irq_desc->lock),
52 #ifdef CONFIG_CPUMASK_OFFSTACK
53 /* We are not allocating a variable-sized bad_irq_desc.affinity */
54 #error "Blackfin architecture does not support CONFIG_CPUMASK_OFFSTACK."
58 int show_interrupts(struct seq_file *p, void *v)
60 int i = *(loff_t *) v, j;
61 struct irqaction *action;
65 spin_lock_irqsave(&irq_desc[i].lock, flags);
66 action = irq_desc[i].action;
69 seq_printf(p, "%3d: ", i);
70 for_each_online_cpu(j)
71 seq_printf(p, "%10u ", kstat_irqs_cpu(i, j));
72 seq_printf(p, " %8s", irq_desc[i].chip->name);
73 seq_printf(p, " %s", action->name);
74 for (action = action->next; action; action = action->next)
75 seq_printf(p, " %s", action->name);
79 spin_unlock_irqrestore(&irq_desc[i].lock, flags);
80 } else if (i == NR_IRQS) {
81 seq_printf(p, "NMI: ");
82 for_each_online_cpu(j)
83 seq_printf(p, "%10u ", cpu_pda[j].__nmi_count);
84 seq_printf(p, " CORE Non Maskable Interrupt\n");
85 seq_printf(p, "Err: %10u\n", atomic_read(&irq_err_count));
92 * do_IRQ handles all hardware IRQs. Decoded IRQs should not
93 * come via this function. Instead, they should provide their
96 #ifdef CONFIG_DO_IRQ_L1
97 __attribute__((l1_text))
99 asmlinkage void asm_do_IRQ(unsigned int irq, struct pt_regs *regs)
102 unsigned short pending, other_ints;
104 struct pt_regs *old_regs = set_irq_regs(regs);
108 #ifdef CONFIG_DEBUG_STACKOVERFLOW
109 /* Debugging check for stack overflow: is there less than STACK_WARN free? */
113 sp = __get_SP() & (THREAD_SIZE-1);
115 if (unlikely(sp < (sizeof(struct thread_info) + STACK_WARN))) {
117 printk(KERN_EMERG "%s: possible stack overflow while handling irq %i "
118 " only %ld bytes free\n",
119 __func__, irq, sp - sizeof(struct thread_info));
125 * Some hardware gives randomly wrong interrupts. Rather
126 * than crashing, do something sensible.
129 handle_bad_irq(irq, &bad_irq_desc);
131 generic_handle_irq(irq);
135 * If we're the only interrupt running (ignoring IRQ15 which
136 * is for syscalls), lower our priority to IRQ14 so that
137 * softirqs run at that level. If there's another,
138 * lower-level interrupt, irq_exit will defer softirqs to
139 * that. If the interrupt pipeline is enabled, we are already
140 * running at IRQ14 priority, so we don't need this code.
143 pending = bfin_read_IPEND() & ~0x8000;
144 other_ints = pending & (pending - 1);
147 #endif /* !CONFIG_IPIPE */
150 set_irq_regs(old_regs);
153 void __init init_IRQ(void)
157 #ifdef CONFIG_DEBUG_BFIN_HWTRACE_EXPAND
158 /* Now that evt_ivhw is set up, turn this on */
159 trace_buff_offset = 0;
160 bfin_write_TBUFCTL(BFIN_TRACE_ON);
161 printk(KERN_INFO "Hardware Trace expanded to %ik\n",
162 1 << CONFIG_DEBUG_BFIN_HWTRACE_EXPAND_LEN);