174 lines
4.6 KiB
C
174 lines
4.6 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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#include <asm/pda.h>
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static atomic_t irq_err_count;
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void ack_bad_irq(unsigned int irq)
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{
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atomic_inc(&irq_err_count);
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printk(KERN_ERR "IRQ: spurious interrupt %d\n", irq);
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}
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static struct irq_desc bad_irq_desc = {
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.handle_irq = handle_bad_irq,
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.lock = __SPIN_LOCK_UNLOCKED(irq_desc->lock),
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};
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#ifdef CONFIG_CPUMASK_OFFSTACK
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/* We are not allocating a variable-sized bad_irq_desc.affinity */
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#error "Blackfin architecture does not support CONFIG_CPUMASK_OFFSTACK."
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#endif
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#ifdef CONFIG_PROC_FS
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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, j;
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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 skip;
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seq_printf(p, "%3d: ", i);
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for_each_online_cpu(j)
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seq_printf(p, "%10u ", kstat_irqs_cpu(i, j));
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seq_printf(p, " %8s", irq_desc[i].chip->name);
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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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skip:
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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, "NMI: ");
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for_each_online_cpu(j)
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seq_printf(p, "%10u ", cpu_pda[j].__nmi_count);
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seq_printf(p, " CORE Non Maskable Interrupt\n");
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seq_printf(p, "Err: %10u\n", atomic_read(&irq_err_count));
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}
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return 0;
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}
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#endif
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#ifdef CONFIG_DEBUG_STACKOVERFLOW
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static void check_stack_overflow(int irq)
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{
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/* Debugging check for stack overflow: is there less than STACK_WARN free? */
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long sp = __get_SP() & (THREAD_SIZE - 1);
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if (unlikely(sp < (sizeof(struct thread_info) + STACK_WARN))) {
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dump_stack();
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pr_emerg("irq%i: possible stack overflow only %ld bytes free\n",
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irq, sp - sizeof(struct thread_info));
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}
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}
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#else
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static inline void check_stack_overflow(int irq) { }
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#endif
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#ifndef CONFIG_IPIPE
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static void maybe_lower_to_irq14(void)
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{
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unsigned short pending, other_ints;
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/*
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* If we're the only interrupt running (ignoring IRQ15 which
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* is for syscalls), lower our priority to IRQ14 so that
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* softirqs run at that level. If there's another,
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* lower-level interrupt, irq_exit will defer softirqs to
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* that. If the interrupt pipeline is enabled, we are already
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* running at IRQ14 priority, so we don't need this code.
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*/
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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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}
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#else
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static inline void maybe_lower_to_irq14(void) { }
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#endif
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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 = set_irq_regs(regs);
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irq_enter();
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check_stack_overflow(irq);
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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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handle_bad_irq(irq, &bad_irq_desc);
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else
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generic_handle_irq(irq);
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maybe_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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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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