MIPS: Don't overflow cevt-r4k.c calculations at high clock rates.
[linux-2.6.git] / arch / blackfin / kernel / irqchip.c
index 07402f5..64cff54 100644 (file)
@@ -1,30 +1,7 @@
 /*
- * File:         arch/blackfin/kernel/irqchip.c
- * Based on:
- * Author:
+ * Copyright 2005-2009 Analog Devices Inc.
  *
- * Created:
- * Description:  This file contains the simple DMA Implementation for Blackfin
- *
- * Modified:
- *               Copyright 2004-2006 Analog Devices Inc.
- *
- * Bugs:         Enter bugs at http://blackfin.uclinux.org/
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, see the file COPYING, or write
- * to the Free Software Foundation, Inc.,
- * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ * Licensed under the GPL-2 or later
  */
 
 #include <linux/kernel_stat.h>
 #include <linux/interrupt.h>
 #include <linux/irq.h>
 #include <asm/trace.h>
+#include <asm/pda.h>
 
-static unsigned long irq_err_count;
-static spinlock_t irq_controller_lock;
-
-/*
- * Dummy mask/unmask handler
- */
-void dummy_mask_unmask_irq(unsigned int irq)
-{
-}
-
+static atomic_t irq_err_count;
 void ack_bad_irq(unsigned int irq)
 {
-       irq_err_count += 1;
+       atomic_inc(&irq_err_count);
        printk(KERN_ERR "IRQ: spurious interrupt %d\n", irq);
 }
-EXPORT_SYMBOL(ack_bad_irq);
-
-static struct irq_chip bad_chip = {
-       .ack = dummy_mask_unmask_irq,
-       .mask = dummy_mask_unmask_irq,
-       .unmask = dummy_mask_unmask_irq,
-};
 
 static struct irq_desc bad_irq_desc = {
-       .status = IRQ_DISABLED,
-       .chip = &bad_chip,
        .handle_irq = handle_bad_irq,
-       .depth = 1,
-       .lock = __SPIN_LOCK_UNLOCKED(irq_desc->lock),
-#ifdef CONFIG_SMP
-       .affinity = CPU_MASK_ALL
-#endif
+       .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;
+       int i = *(loff_t *) v, j;
        struct irqaction *action;
        unsigned long flags;
 
        if (i < NR_IRQS) {
-               spin_lock_irqsave(&irq_desc[i].lock, flags);
+               raw_spin_lock_irqsave(&irq_desc[i].lock, flags);
                action = irq_desc[i].action;
                if (!action)
-                       goto unlock;
-
-               seq_printf(p, "%3d: %10u ", i, kstat_irqs(i));
+                       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[i].chip->name);
                seq_printf(p, "  %s", action->name);
                for (action = action->next; action; action = action->next)
-                       seq_printf(p, ", %s", action->name);
+                       seq_printf(p, "  %s", action->name);
 
                seq_putc(p, '\n');
- unlock:
-               spin_unlock_irqrestore(&irq_desc[i].lock, flags);
+ skip:
+               raw_spin_unlock_irqrestore(&irq_desc[i].lock, flags);
        } else if (i == NR_IRQS) {
-               seq_printf(p, "Err: %10lu\n", irq_err_count);
+               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;
-       struct irq_desc *desc = irq_desc + irq;
-       unsigned short pending, other_ints;
+       struct pt_regs *old_regs = set_irq_regs(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)
-               desc = &bad_irq_desc;
-
-       irq_enter();
+               handle_bad_irq(irq, &bad_irq_desc);
+       else
+               generic_handle_irq(irq);
 
-       generic_handle_irq(irq);
+       maybe_lower_to_irq14();
 
-       /* 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.  */
-       CSYNC();
-       pending = bfin_read_IPEND() & ~0x8000;
-       other_ints = pending & (pending - 1);
-       if (other_ints == 0)
-               lower_to_irq14();
        irq_exit();
 
        set_irq_regs(old_regs);
@@ -140,14 +138,6 @@ asmlinkage void asm_do_IRQ(unsigned int irq, struct pt_regs *regs)
 
 void __init init_IRQ(void)
 {
-       struct irq_desc *desc;
-       int irq;
-
-       spin_lock_init(&irq_controller_lock);
-       for (irq = 0, desc = irq_desc; irq < NR_IRQS; irq++, desc++) {
-               *desc = bad_irq_desc;
-       }
-
        init_arch_irq();
 
 #ifdef CONFIG_DEBUG_BFIN_HWTRACE_EXPAND