1 /* 2 * Copyright (C) 1992, 1998 Linus Torvalds, Ingo Molnar 3 * 4 * This file contains the lowest level x86_64-specific interrupt 5 * entry and irq statistics code. All the remaining irq logic is 6 * done by the generic kernel/irq/ code and in the 7 * x86_64-specific irq controller code. (e.g. i8259.c and 8 * io_apic.c.) 9 */ 10 11 #include <linux/kernel_stat.h> 12 #include <linux/interrupt.h> 13 #include <linux/seq_file.h> 14 #include <linux/module.h> 15 #include <linux/delay.h> 16 #include <asm/uaccess.h> 17 #include <asm/io_apic.h> 18 #include <asm/idle.h> 19 #include <asm/smp.h> 20 21 atomic_t irq_err_count; 22 23 #ifdef CONFIG_DEBUG_STACKOVERFLOW 24 /* 25 * Probabilistic stack overflow check: 26 * 27 * Only check the stack in process context, because everything else 28 * runs on the big interrupt stacks. Checking reliably is too expensive, 29 * so we just check from interrupts. 30 */ 31 static inline void stack_overflow_check(struct pt_regs *regs) 32 { 33 u64 curbase = (u64)task_stack_page(current); 34 static unsigned long warned = -60*HZ; 35 36 if (regs->rsp >= curbase && regs->rsp <= curbase + THREAD_SIZE && 37 regs->rsp < curbase + sizeof(struct thread_info) + 128 && 38 time_after(jiffies, warned + 60*HZ)) { 39 printk("do_IRQ: %s near stack overflow (cur:%Lx,rsp:%lx)\n", 40 current->comm, curbase, regs->rsp); 41 show_stack(NULL,NULL); 42 warned = jiffies; 43 } 44 } 45 #endif 46 47 /* 48 * Generic, controller-independent functions: 49 */ 50 51 int show_interrupts(struct seq_file *p, void *v) 52 { 53 int i = *(loff_t *) v, j; 54 struct irqaction * action; 55 unsigned long flags; 56 57 if (i == 0) { 58 seq_printf(p, " "); 59 for_each_online_cpu(j) 60 seq_printf(p, "CPU%-8d",j); 61 seq_putc(p, '\n'); 62 } 63 64 if (i < NR_IRQS) { 65 unsigned any_count = 0; 66 67 spin_lock_irqsave(&irq_desc[i].lock, flags); 68 #ifndef CONFIG_SMP 69 any_count = kstat_irqs(i); 70 #else 71 for_each_online_cpu(j) 72 any_count |= kstat_cpu(j).irqs[i]; 73 #endif 74 action = irq_desc[i].action; 75 if (!action && !any_count) 76 goto skip; 77 seq_printf(p, "%3d: ",i); 78 #ifndef CONFIG_SMP 79 seq_printf(p, "%10u ", kstat_irqs(i)); 80 #else 81 for_each_online_cpu(j) 82 seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]); 83 #endif 84 seq_printf(p, " %8s", irq_desc[i].chip->name); 85 seq_printf(p, "-%-8s", irq_desc[i].name); 86 87 if (action) { 88 seq_printf(p, " %s", action->name); 89 while ((action = action->next) != NULL) 90 seq_printf(p, ", %s", action->name); 91 } 92 seq_putc(p, '\n'); 93 skip: 94 spin_unlock_irqrestore(&irq_desc[i].lock, flags); 95 } else if (i == NR_IRQS) { 96 seq_printf(p, "NMI: "); 97 for_each_online_cpu(j) 98 seq_printf(p, "%10u ", cpu_pda(j)->__nmi_count); 99 seq_printf(p, " Non-maskable interrupts\n"); 100 seq_printf(p, "LOC: "); 101 for_each_online_cpu(j) 102 seq_printf(p, "%10u ", cpu_pda(j)->apic_timer_irqs); 103 seq_printf(p, " Local timer interrupts\n"); 104 #ifdef CONFIG_SMP 105 seq_printf(p, "RES: "); 106 for_each_online_cpu(j) 107 seq_printf(p, "%10u ", cpu_pda(j)->irq_resched_count); 108 seq_printf(p, " Rescheduling interrupts\n"); 109 seq_printf(p, "CAL: "); 110 for_each_online_cpu(j) 111 seq_printf(p, "%10u ", cpu_pda(j)->irq_call_count); 112 seq_printf(p, " function call interrupts\n"); 113 seq_printf(p, "TLB: "); 114 for_each_online_cpu(j) 115 seq_printf(p, "%10u ", cpu_pda(j)->irq_tlb_count); 116 seq_printf(p, " TLB shootdowns\n"); 117 #endif 118 seq_printf(p, "TRM: "); 119 for_each_online_cpu(j) 120 seq_printf(p, "%10u ", cpu_pda(j)->irq_thermal_count); 121 seq_printf(p, " Thermal event interrupts\n"); 122 seq_printf(p, "THR: "); 123 for_each_online_cpu(j) 124 seq_printf(p, "%10u ", cpu_pda(j)->irq_threshold_count); 125 seq_printf(p, " Threshold APIC interrupts\n"); 126 seq_printf(p, "SPU: "); 127 for_each_online_cpu(j) 128 seq_printf(p, "%10u ", cpu_pda(j)->irq_spurious_count); 129 seq_printf(p, " Spurious interrupts\n"); 130 seq_printf(p, "ERR: %10u\n", atomic_read(&irq_err_count)); 131 } 132 return 0; 133 } 134 135 /* 136 * do_IRQ handles all normal device IRQ's (the special 137 * SMP cross-CPU interrupts have their own specific 138 * handlers). 139 */ 140 asmlinkage unsigned int do_IRQ(struct pt_regs *regs) 141 { 142 struct pt_regs *old_regs = set_irq_regs(regs); 143 144 /* high bit used in ret_from_ code */ 145 unsigned vector = ~regs->orig_rax; 146 unsigned irq; 147 148 exit_idle(); 149 irq_enter(); 150 irq = __get_cpu_var(vector_irq)[vector]; 151 152 #ifdef CONFIG_DEBUG_STACKOVERFLOW 153 stack_overflow_check(regs); 154 #endif 155 156 if (likely(irq < NR_IRQS)) 157 generic_handle_irq(irq); 158 else { 159 if (!disable_apic) 160 ack_APIC_irq(); 161 162 if (printk_ratelimit()) 163 printk(KERN_EMERG "%s: %d.%d No irq handler for vector\n", 164 __func__, smp_processor_id(), vector); 165 } 166 167 irq_exit(); 168 169 set_irq_regs(old_regs); 170 return 1; 171 } 172 173 #ifdef CONFIG_HOTPLUG_CPU 174 void fixup_irqs(cpumask_t map) 175 { 176 unsigned int irq; 177 static int warned; 178 179 for (irq = 0; irq < NR_IRQS; irq++) { 180 cpumask_t mask; 181 int break_affinity = 0; 182 int set_affinity = 1; 183 184 if (irq == 2) 185 continue; 186 187 /* interrupt's are disabled at this point */ 188 spin_lock(&irq_desc[irq].lock); 189 190 if (!irq_has_action(irq) || 191 cpus_equal(irq_desc[irq].affinity, map)) { 192 spin_unlock(&irq_desc[irq].lock); 193 continue; 194 } 195 196 cpus_and(mask, irq_desc[irq].affinity, map); 197 if (cpus_empty(mask)) { 198 break_affinity = 1; 199 mask = map; 200 } 201 202 if (irq_desc[irq].chip->mask) 203 irq_desc[irq].chip->mask(irq); 204 205 if (irq_desc[irq].chip->set_affinity) 206 irq_desc[irq].chip->set_affinity(irq, mask); 207 else if (!(warned++)) 208 set_affinity = 0; 209 210 if (irq_desc[irq].chip->unmask) 211 irq_desc[irq].chip->unmask(irq); 212 213 spin_unlock(&irq_desc[irq].lock); 214 215 if (break_affinity && set_affinity) 216 printk("Broke affinity for irq %i\n", irq); 217 else if (!set_affinity) 218 printk("Cannot set affinity for irq %i\n", irq); 219 } 220 221 /* That doesn't seem sufficient. Give it 1ms. */ 222 local_irq_enable(); 223 mdelay(1); 224 local_irq_disable(); 225 } 226 #endif 227 228 extern void call_softirq(void); 229 230 asmlinkage void do_softirq(void) 231 { 232 __u32 pending; 233 unsigned long flags; 234 235 if (in_interrupt()) 236 return; 237 238 local_irq_save(flags); 239 pending = local_softirq_pending(); 240 /* Switch to interrupt stack */ 241 if (pending) { 242 call_softirq(); 243 WARN_ON_ONCE(softirq_count()); 244 } 245 local_irq_restore(flags); 246 } 247