1/* 2 * Copyright (C) 1999, 2005 MIPS Technologies, Inc. All rights reserved. 3 * 4 * This program is free software; you can distribute it and/or modify it 5 * under the terms of the GNU General Public License (Version 2) as 6 * published by the Free Software Foundation. 7 * 8 * This program is distributed in the hope it will be useful, but WITHOUT 9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 10 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 11 * for more details. 12 * 13 * You should have received a copy of the GNU General Public License along 14 * with this program; if not, write to the Free Software Foundation, Inc., 15 * 59 Temple Place - Suite 330, Boston MA 02111-1307, USA. 16 * 17 */ 18#include <linux/init.h> 19#include <linux/sched.h> 20#include <linux/interrupt.h> 21#include <linux/kernel_stat.h> 22#include <asm/mips-boards/simint.h> 23#include <asm/irq_cpu.h> 24 25static inline int clz(unsigned long x) 26{ 27 __asm__( 28 " .set push \n" 29 " .set mips32 \n" 30 " clz %0, %1 \n" 31 " .set pop \n" 32 : "=r" (x) 33 : "r" (x)); 34 35 return x; 36} 37 38/* 39 * Version of ffs that only looks at bits 12..15. 40 */ 41static inline unsigned int irq_ffs(unsigned int pending) 42{ 43#if defined(CONFIG_CPU_MIPS32) || defined(CONFIG_CPU_MIPS64) 44 return -clz(pending) + 31 - CAUSEB_IP; 45#else 46 unsigned int a0 = 7; 47 unsigned int t0; 48 49 t0 = s0 & 0xf000; 50 t0 = t0 < 1; 51 t0 = t0 << 2; 52 a0 = a0 - t0; 53 s0 = s0 << t0; 54 55 t0 = s0 & 0xc000; 56 t0 = t0 < 1; 57 t0 = t0 << 1; 58 a0 = a0 - t0; 59 s0 = s0 << t0; 60 61 t0 = s0 & 0x8000; 62 t0 = t0 < 1; 63 /* t0 = t0 << 2; */ 64 a0 = a0 - t0; 65 /* s0 = s0 << t0; */ 66 67 return a0; 68#endif 69} 70 71asmlinkage void plat_irq_dispatch(void) 72{ 73 unsigned int pending = read_c0_cause() & read_c0_status() & ST0_IM; 74 int irq; 75 76 irq = irq_ffs(pending); 77 78 if (irq > 0) 79 do_IRQ(MIPS_CPU_IRQ_BASE + irq); 80 else 81 spurious_interrupt(); 82} 83 84void __init arch_init_irq(void) 85{ 86 mips_cpu_irq_init(); 87} 88