1 /* 2 * linux/arch/xtensa/kernel/irq.c 3 * 4 * Xtensa built-in interrupt controller and some generic functions copied 5 * from i386. 6 * 7 * Copyright (C) 2002 - 2005 Tensilica, Inc. 8 * Copyright (C) 1992, 1998 Linus Torvalds, Ingo Molnar 9 * 10 * 11 * Chris Zankel <chris@zankel.net> 12 * Kevin Chea 13 * 14 */ 15 16 #include <linux/module.h> 17 #include <linux/seq_file.h> 18 #include <linux/interrupt.h> 19 #include <linux/irq.h> 20 #include <linux/kernel_stat.h> 21 22 #include <asm/uaccess.h> 23 #include <asm/platform.h> 24 25 static void enable_xtensa_irq(unsigned int irq); 26 static void disable_xtensa_irq(unsigned int irq); 27 static void mask_and_ack_xtensa(unsigned int irq); 28 static void end_xtensa_irq(unsigned int irq); 29 30 static unsigned int cached_irq_mask; 31 32 atomic_t irq_err_count; 33 34 /* 35 * 'what should we do if we get a hw irq event on an illegal vector'. 36 * each architecture has to answer this themselves. 37 */ 38 void ack_bad_irq(unsigned int irq) 39 { 40 printk("unexpected IRQ trap at vector %02x\n", irq); 41 } 42 43 /* 44 * do_IRQ handles all normal device IRQ's (the special 45 * SMP cross-CPU interrupts have their own specific 46 * handlers). 47 */ 48 49 unsigned int do_IRQ(int irq, struct pt_regs *regs) 50 { 51 irq_enter(); 52 53 #ifdef CONFIG_DEBUG_STACKOVERFLOW 54 /* Debugging check for stack overflow: is there less than 1KB free? */ 55 { 56 unsigned long sp; 57 58 __asm__ __volatile__ ("mov %0, a1\n" : "=a" (sp)); 59 sp &= THREAD_SIZE - 1; 60 61 if (unlikely(sp < (sizeof(thread_info) + 1024))) 62 printk("Stack overflow in do_IRQ: %ld\n", 63 sp - sizeof(struct thread_info)); 64 } 65 #endif 66 67 __do_IRQ(irq, regs); 68 69 irq_exit(); 70 71 return 1; 72 } 73 74 /* 75 * Generic, controller-independent functions: 76 */ 77 78 int show_interrupts(struct seq_file *p, void *v) 79 { 80 int i = *(loff_t *) v, j; 81 struct irqaction * action; 82 unsigned long flags; 83 84 if (i == 0) { 85 seq_printf(p, " "); 86 for_each_online_cpu(j) 87 seq_printf(p, "CPU%d ",j); 88 seq_putc(p, '\n'); 89 } 90 91 if (i < NR_IRQS) { 92 spin_lock_irqsave(&irq_desc[i].lock, flags); 93 action = irq_desc[i].action; 94 if (!action) 95 goto skip; 96 seq_printf(p, "%3d: ",i); 97 #ifndef CONFIG_SMP 98 seq_printf(p, "%10u ", kstat_irqs(i)); 99 #else 100 for_each_online_cpu(j) 101 seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]); 102 #endif 103 seq_printf(p, " %14s", irq_desc[i].chip->typename); 104 seq_printf(p, " %s", action->name); 105 106 for (action=action->next; action; action = action->next) 107 seq_printf(p, ", %s", action->name); 108 109 seq_putc(p, '\n'); 110 skip: 111 spin_unlock_irqrestore(&irq_desc[i].lock, flags); 112 } else if (i == NR_IRQS) { 113 seq_printf(p, "NMI: "); 114 for_each_online_cpu(j) 115 seq_printf(p, "%10u ", nmi_count(j)); 116 seq_putc(p, '\n'); 117 seq_printf(p, "ERR: %10u\n", atomic_read(&irq_err_count)); 118 } 119 return 0; 120 } 121 /* shutdown is same as "disable" */ 122 #define shutdown_xtensa_irq disable_xtensa_irq 123 124 static unsigned int startup_xtensa_irq(unsigned int irq) 125 { 126 enable_xtensa_irq(irq); 127 return 0; /* never anything pending */ 128 } 129 130 static struct hw_interrupt_type xtensa_irq_type = { 131 "Xtensa-IRQ", 132 startup_xtensa_irq, 133 shutdown_xtensa_irq, 134 enable_xtensa_irq, 135 disable_xtensa_irq, 136 mask_and_ack_xtensa, 137 end_xtensa_irq 138 }; 139 140 static inline void mask_irq(unsigned int irq) 141 { 142 cached_irq_mask &= ~(1 << irq); 143 set_sr (cached_irq_mask, INTENABLE); 144 } 145 146 static inline void unmask_irq(unsigned int irq) 147 { 148 cached_irq_mask |= 1 << irq; 149 set_sr (cached_irq_mask, INTENABLE); 150 } 151 152 static void disable_xtensa_irq(unsigned int irq) 153 { 154 unsigned long flags; 155 local_save_flags(flags); 156 mask_irq(irq); 157 local_irq_restore(flags); 158 } 159 160 static void enable_xtensa_irq(unsigned int irq) 161 { 162 unsigned long flags; 163 local_save_flags(flags); 164 unmask_irq(irq); 165 local_irq_restore(flags); 166 } 167 168 static void mask_and_ack_xtensa(unsigned int irq) 169 { 170 disable_xtensa_irq(irq); 171 } 172 173 static void end_xtensa_irq(unsigned int irq) 174 { 175 enable_xtensa_irq(irq); 176 } 177 178 179 void __init init_IRQ(void) 180 { 181 int i; 182 183 for (i=0; i < XTENSA_NR_IRQS; i++) 184 irq_desc[i].chip = &xtensa_irq_type; 185 186 cached_irq_mask = 0; 187 188 platform_init_irq(); 189 } 190