f0b5d12f2b
- allow people to select the feature that is unavailable to the kernel: NMI, JTAG, or CYCLES. - change default NMI handler to simply dump hardware trace buffer. - remove default NMI handler completely as calling into kernel code is not safe move example handler to wiki so people dont haphazardly copy and paste this stuff thinking its safe Signed-off-by: Mike Frysinger <michael.frysinger@analog.com> Signed-off-by: Bryan Wu <bryan.wu@analog.com>
156 lines
3.8 KiB
C
156 lines
3.8 KiB
C
/*
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* File: arch/blackfin/kernel/irqchip.c
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* Based on:
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* Author:
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*
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* Created:
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* Description: This file contains the simple DMA Implementation for Blackfin
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*
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* Modified:
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* Copyright 2004-2006 Analog Devices Inc.
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*
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* Bugs: Enter bugs at http://blackfin.uclinux.org/
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, see the file COPYING, or write
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* to the Free Software Foundation, Inc.,
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* 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#include <linux/kernel_stat.h>
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#include <linux/module.h>
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#include <linux/random.h>
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#include <linux/seq_file.h>
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#include <linux/kallsyms.h>
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#include <linux/interrupt.h>
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#include <linux/irq.h>
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#include <asm/trace.h>
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static unsigned long irq_err_count;
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static spinlock_t irq_controller_lock;
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/*
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* Dummy mask/unmask handler
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*/
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void dummy_mask_unmask_irq(unsigned int irq)
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{
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}
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void ack_bad_irq(unsigned int irq)
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{
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irq_err_count += 1;
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printk(KERN_ERR "IRQ: spurious interrupt %d\n", irq);
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}
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EXPORT_SYMBOL(ack_bad_irq);
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static struct irq_chip bad_chip = {
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.ack = dummy_mask_unmask_irq,
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.mask = dummy_mask_unmask_irq,
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.unmask = dummy_mask_unmask_irq,
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};
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static struct irq_desc bad_irq_desc = {
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.chip = &bad_chip,
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.handle_irq = handle_bad_irq,
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.depth = 1,
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};
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int show_interrupts(struct seq_file *p, void *v)
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{
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int i = *(loff_t *) v;
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struct irqaction *action;
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unsigned long flags;
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if (i < NR_IRQS) {
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spin_lock_irqsave(&irq_desc[i].lock, flags);
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action = irq_desc[i].action;
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if (!action)
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goto unlock;
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seq_printf(p, "%3d: %10u ", i, kstat_irqs(i));
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seq_printf(p, " %s", action->name);
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for (action = action->next; action; action = action->next)
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seq_printf(p, ", %s", action->name);
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seq_putc(p, '\n');
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unlock:
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spin_unlock_irqrestore(&irq_desc[i].lock, flags);
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} else if (i == NR_IRQS) {
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seq_printf(p, "Err: %10lu\n", irq_err_count);
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}
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return 0;
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}
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/*
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* do_IRQ handles all hardware IRQs. Decoded IRQs should not
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* come via this function. Instead, they should provide their
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* own 'handler'
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*/
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#ifdef CONFIG_DO_IRQ_L1
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__attribute__((l1_text))
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#endif
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asmlinkage void asm_do_IRQ(unsigned int irq, struct pt_regs *regs)
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{
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struct pt_regs *old_regs;
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struct irq_desc *desc = irq_desc + irq;
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unsigned short pending, other_ints;
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old_regs = set_irq_regs(regs);
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/*
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* Some hardware gives randomly wrong interrupts. Rather
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* than crashing, do something sensible.
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*/
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if (irq >= NR_IRQS)
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desc = &bad_irq_desc;
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irq_enter();
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generic_handle_irq(irq);
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/* If we're the only interrupt running (ignoring IRQ15 which is for
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syscalls), lower our priority to IRQ14 so that softirqs run at
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that level. If there's another, lower-level interrupt, irq_exit
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will defer softirqs to that. */
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CSYNC();
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pending = bfin_read_IPEND() & ~0x8000;
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other_ints = pending & (pending - 1);
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if (other_ints == 0)
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lower_to_irq14();
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irq_exit();
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set_irq_regs(old_regs);
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}
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void __init init_IRQ(void)
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{
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struct irq_desc *desc;
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int irq;
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spin_lock_init(&irq_controller_lock);
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for (irq = 0, desc = irq_desc; irq < NR_IRQS; irq++, desc++) {
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*desc = bad_irq_desc;
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}
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init_arch_irq();
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#ifdef CONFIG_DEBUG_BFIN_HWTRACE_EXPAND
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/* Now that evt_ivhw is set up, turn this on */
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trace_buff_offset = 0;
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bfin_write_TBUFCTL(BFIN_TRACE_ON);
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printk(KERN_INFO "Hardware Trace expanded to %ik\n",
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1 << CONFIG_DEBUG_BFIN_HWTRACE_EXPAND_LEN);
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#endif
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}
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