arch/mips/galileo-boards/ev96100/irq.c

   1 /*
   2  * Copyright 2000 MontaVista Software Inc.
   3  * Author: MontaVista Software, Inc.
   4  *              ppopov@mvista.com or source@mvista.com
   5  *
   6  * This file was derived from Carsten Langgaard's
   7  * arch/mips/mips-boards/atlas/atlas_int.c.
   8  *
   9  * Carsten Langgaard, carstenl@mips.com
  10  * Copyright (C) 1999,2000 MIPS Technologies, Inc.  All rights reserved.
  11  *
  12  *  This program is free software; you can redistribute  it and/or modify it
  13  *  under  the terms of  the GNU General  Public License as published by the
  14  *  Free Software Foundation;  either version 2 of the  License, or (at your
  15  *  option) any later version.
  16  *
  17  *  THIS  SOFTWARE  IS PROVIDED   ``AS  IS'' AND   ANY  EXPRESS OR IMPLIED
  18  *  WARRANTIES,   INCLUDING, BUT NOT  LIMITED  TO, THE IMPLIED WARRANTIES OF
  19  *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN
  20  *  NO  EVENT  SHALL   THE AUTHOR  BE    LIABLE FOR ANY   DIRECT, INDIRECT,
  21  *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  22  *  NOT LIMITED   TO, PROCUREMENT OF  SUBSTITUTE GOODS  OR SERVICES; LOSS OF
  23  *  USE, DATA,  OR PROFITS; OR  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
  24  *  ANY THEORY OF LIABILITY, WHETHER IN  CONTRACT, STRICT LIABILITY, OR TORT
  25  *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  26  *  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27  *
  28  *  You should have received a copy of the  GNU General Public License along
  29  *  with this program; if not, write  to the Free Software Foundation, Inc.,
  30  *  675 Mass Ave, Cambridge, MA 02139, USA.
  31  */
  32 #include <linux/errno.h>
  33 #include <linux/init.h>
  34 #include <linux/kernel_stat.h>
  35 #include <linux/irq.h>
  36 #include <linux/module.h>
  37 #include <linux/signal.h>
  38 #include <linux/sched.h>
  39 #include <linux/types.h>
  40 #include <linux/interrupt.h>
  41 #include <asm/irq_cpu.h>
  42
  43 static inline unsigned int ffz8(unsigned int word)
  44 {
  45         unsigned long k;
  46
  47         k = 7;
  48         if (word & 0x0fUL) { k -= 4;  word <<= 4;  }
  49         if (word & 0x30UL) { k -= 2;  word <<= 2;  }
  50         if (word & 0x40UL) { k -= 1; }
  51
  52         return k;
  53 }
  54
  55 extern void mips_timer_interrupt(struct pt_regs *regs);
  56
  57 asmlinkage void ev96100_cpu_irq(unsigned int pending, struct pt_regs *regs)
  58 {
  59         do_IRQ(ffz8(pending >> 8), regs);
  60 }
  61
  62 asmlinkage void plat_irq_dispatch(struct pt_regs *regs)
  63 {
  64         unsigned int pending = read_c0_cause() & read_c0_status() & ST0_IM;
  65
  66         if (pending & CAUSEF_IP7)
  67                 mips_timer_interrupt(regs);
  68         else if (pending)
  69                 ev96100_cpu_irq(pending, regs);
  70         else
  71                 spurious_interrupt(regs);
  72 }
  73
  74 void __init arch_init_irq(void)
  75 {
  76         mips_cpu_irq_init(0);
  77 }