1/* 2 * linux/arch/sh/kernel/irq.c 3 * 4 * Copyright (C) 1992, 1998 Linus Torvalds, Ingo Molnar 5 * 6 * 7 * SuperH version: Copyright (C) 1999 Niibe Yutaka 8 */ 9#include <linux/irq.h> 10#include <linux/interrupt.h> 11#include <linux/module.h> 12#include <linux/kernel_stat.h> 13#include <linux/seq_file.h> 14#include <linux/ftrace.h> 15#include <linux/delay.h> 16#include <asm/processor.h> 17#include <asm/machvec.h> 18#include <asm/uaccess.h> 19#include <asm/thread_info.h> 20#include <cpu/mmu_context.h> 21 22atomic_t irq_err_count; 23 24/* 25 * 'what should we do if we get a hw irq event on an illegal vector'. 26 * each architecture has to answer this themselves, it doesn't deserve 27 * a generic callback i think. 28 */ 29void ack_bad_irq(unsigned int irq) 30{ 31 atomic_inc(&irq_err_count); 32 printk("unexpected IRQ trap at vector %02x\n", irq); 33} 34 35#if defined(CONFIG_PROC_FS) 36/* 37 * /proc/interrupts printing: 38 */ 39static int show_other_interrupts(struct seq_file *p, int prec) 40{ 41 int j; 42 43 seq_printf(p, "%*s: ", prec, "NMI"); 44 for_each_online_cpu(j) 45 seq_printf(p, "%10u ", irq_stat[j].__nmi_count); 46 seq_printf(p, " Non-maskable interrupts\n"); 47 48 seq_printf(p, "%*s: %10u\n", prec, "ERR", atomic_read(&irq_err_count)); 49 50 return 0; 51} 52 53int show_interrupts(struct seq_file *p, void *v) 54{ 55 unsigned long flags, any_count = 0; 56 int i = *(loff_t *)v, j, prec; 57 struct irqaction *action; 58 struct irq_desc *desc; 59 60 if (i > nr_irqs) 61 return 0; 62 63 for (prec = 3, j = 1000; prec < 10 && j <= nr_irqs; ++prec) 64 j *= 10; 65 66 if (i == nr_irqs) 67 return show_other_interrupts(p, prec); 68 69 if (i == 0) { 70 seq_printf(p, "%*s", prec + 8, ""); 71 for_each_online_cpu(j) 72 seq_printf(p, "CPU%-8d", j); 73 seq_putc(p, '\n'); 74 } 75 76 desc = irq_to_desc(i); 77 if (!desc) 78 return 0; 79 80 raw_spin_lock_irqsave(&desc->lock, flags); 81 for_each_online_cpu(j) 82 any_count |= kstat_irqs_cpu(i, j); 83 action = desc->action; 84 if (!action && !any_count) 85 goto out; 86 87 seq_printf(p, "%*d: ", prec, i); 88 for_each_online_cpu(j) 89 seq_printf(p, "%10u ", kstat_irqs_cpu(i, j)); 90 seq_printf(p, " %14s", desc->chip->name); 91 seq_printf(p, "-%-8s", desc->name); 92 93 if (action) { 94 seq_printf(p, " %s", action->name); 95 while ((action = action->next) != NULL) 96 seq_printf(p, ", %s", action->name); 97 } 98 99 seq_putc(p, '\n'); 100out: 101 raw_spin_unlock_irqrestore(&desc->lock, flags); 102 return 0; 103} 104#endif 105 106#ifdef CONFIG_IRQSTACKS 107/* 108 * per-CPU IRQ handling contexts (thread information and stack) 109 */ 110union irq_ctx { 111 struct thread_info tinfo; 112 u32 stack[THREAD_SIZE/sizeof(u32)]; 113}; 114 115static union irq_ctx *hardirq_ctx[NR_CPUS] __read_mostly; 116static union irq_ctx *softirq_ctx[NR_CPUS] __read_mostly; 117 118static char softirq_stack[NR_CPUS * THREAD_SIZE] __page_aligned_bss; 119static char hardirq_stack[NR_CPUS * THREAD_SIZE] __page_aligned_bss; 120 121static inline void handle_one_irq(unsigned int irq) 122{ 123 union irq_ctx *curctx, *irqctx; 124 125 curctx = (union irq_ctx *)current_thread_info(); 126 irqctx = hardirq_ctx[smp_processor_id()]; 127 128 /* 129 * this is where we switch to the IRQ stack. However, if we are 130 * already using the IRQ stack (because we interrupted a hardirq 131 * handler) we can't do that and just have to keep using the 132 * current stack (which is the irq stack already after all) 133 */ 134 if (curctx != irqctx) { 135 u32 *isp; 136 137 isp = (u32 *)((char *)irqctx + sizeof(*irqctx)); 138 irqctx->tinfo.task = curctx->tinfo.task; 139 irqctx->tinfo.previous_sp = current_stack_pointer; 140 141 /* 142 * Copy the softirq bits in preempt_count so that the 143 * softirq checks work in the hardirq context. 144 */ 145 irqctx->tinfo.preempt_count = 146 (irqctx->tinfo.preempt_count & ~SOFTIRQ_MASK) | 147 (curctx->tinfo.preempt_count & SOFTIRQ_MASK); 148 149 __asm__ __volatile__ ( 150 "mov %0, r4 \n" 151 "mov r15, r8 \n" 152 "jsr @%1 \n" 153 /* swith to the irq stack */ 154 " mov %2, r15 \n" 155 /* restore the stack (ring zero) */ 156 "mov r8, r15 \n" 157 : /* no outputs */ 158 : "r" (irq), "r" (generic_handle_irq), "r" (isp) 159 : "memory", "r0", "r1", "r2", "r3", "r4", 160 "r5", "r6", "r7", "r8", "t", "pr" 161 ); 162 } else 163 generic_handle_irq(irq); 164} 165 166/* 167 * allocate per-cpu stacks for hardirq and for softirq processing 168 */ 169void irq_ctx_init(int cpu) 170{ 171 union irq_ctx *irqctx; 172 173 if (hardirq_ctx[cpu]) 174 return; 175 176 irqctx = (union irq_ctx *)&hardirq_stack[cpu * THREAD_SIZE]; 177 irqctx->tinfo.task = NULL; 178 irqctx->tinfo.exec_domain = NULL; 179 irqctx->tinfo.cpu = cpu; 180 irqctx->tinfo.preempt_count = HARDIRQ_OFFSET; 181 irqctx->tinfo.addr_limit = MAKE_MM_SEG(0); 182 183 hardirq_ctx[cpu] = irqctx; 184 185 irqctx = (union irq_ctx *)&softirq_stack[cpu * THREAD_SIZE]; 186 irqctx->tinfo.task = NULL; 187 irqctx->tinfo.exec_domain = NULL; 188 irqctx->tinfo.cpu = cpu; 189 irqctx->tinfo.preempt_count = 0; 190 irqctx->tinfo.addr_limit = MAKE_MM_SEG(0); 191 192 softirq_ctx[cpu] = irqctx; 193 194 printk("CPU %u irqstacks, hard=%p soft=%p\n", 195 cpu, hardirq_ctx[cpu], softirq_ctx[cpu]); 196} 197 198void irq_ctx_exit(int cpu) 199{ 200 hardirq_ctx[cpu] = NULL; 201} 202 203asmlinkage void do_softirq(void) 204{ 205 unsigned long flags; 206 struct thread_info *curctx; 207 union irq_ctx *irqctx; 208 u32 *isp; 209 210 if (in_interrupt()) 211 return; 212 213 local_irq_save(flags); 214 215 if (local_softirq_pending()) { 216 curctx = current_thread_info(); 217 irqctx = softirq_ctx[smp_processor_id()]; 218 irqctx->tinfo.task = curctx->task; 219 irqctx->tinfo.previous_sp = current_stack_pointer; 220 221 /* build the stack frame on the softirq stack */ 222 isp = (u32 *)((char *)irqctx + sizeof(*irqctx)); 223 224 __asm__ __volatile__ ( 225 "mov r15, r9 \n" 226 "jsr @%0 \n" 227 /* switch to the softirq stack */ 228 " mov %1, r15 \n" 229 /* restore the thread stack */ 230 "mov r9, r15 \n" 231 : /* no outputs */ 232 : "r" (__do_softirq), "r" (isp) 233 : "memory", "r0", "r1", "r2", "r3", "r4", 234 "r5", "r6", "r7", "r8", "r9", "r15", "t", "pr" 235 ); 236 237 /* 238 * Shouldnt happen, we returned above if in_interrupt(): 239 */ 240 WARN_ON_ONCE(softirq_count()); 241 } 242 243 local_irq_restore(flags); 244} 245#else 246static inline void handle_one_irq(unsigned int irq) 247{ 248 generic_handle_irq(irq); 249} 250#endif 251 252asmlinkage __irq_entry int do_IRQ(unsigned int irq, struct pt_regs *regs) 253{ 254 struct pt_regs *old_regs = set_irq_regs(regs); 255 256 irq_enter(); 257 258 irq = irq_demux(irq_lookup(irq)); 259 260 if (irq != NO_IRQ_IGNORE) { 261 handle_one_irq(irq); 262 irq_finish(irq); 263 } 264 265 irq_exit(); 266 267 set_irq_regs(old_regs); 268 269 return IRQ_HANDLED; 270} 271 272void __init init_IRQ(void) 273{ 274 plat_irq_setup(); 275 276 /* 277 * Pin any of the legacy IRQ vectors that haven't already been 278 * grabbed by the platform 279 */ 280 reserve_irq_legacy(); 281 282 /* Perform the machine specific initialisation */ 283 if (sh_mv.mv_init_irq) 284 sh_mv.mv_init_irq(); 285 286 irq_ctx_init(smp_processor_id()); 287} 288 289#ifdef CONFIG_SPARSE_IRQ 290int __init arch_probe_nr_irqs(void) 291{ 292 nr_irqs = sh_mv.mv_nr_irqs; 293 return 0; 294} 295#endif 296 297#ifdef CONFIG_HOTPLUG_CPU 298static void route_irq(struct irq_desc *desc, unsigned int irq, unsigned int cpu) 299{ 300 printk(KERN_INFO "IRQ%u: moving from cpu%u to cpu%u\n", 301 irq, desc->node, cpu); 302 303 raw_spin_lock_irq(&desc->lock); 304 desc->chip->set_affinity(irq, cpumask_of(cpu)); 305 raw_spin_unlock_irq(&desc->lock); 306} 307 308/* 309 * The CPU has been marked offline. Migrate IRQs off this CPU. If 310 * the affinity settings do not allow other CPUs, force them onto any 311 * available CPU. 312 */ 313void migrate_irqs(void) 314{ 315 struct irq_desc *desc; 316 unsigned int irq, cpu = smp_processor_id(); 317 318 for_each_irq_desc(irq, desc) { 319 if (desc->node == cpu) { 320 unsigned int newcpu = cpumask_any_and(desc->affinity, 321 cpu_online_mask); 322 if (newcpu >= nr_cpu_ids) { 323 if (printk_ratelimit()) 324 printk(KERN_INFO "IRQ%u no longer affine to CPU%u\n", 325 irq, cpu); 326 327 cpumask_setall(desc->affinity); 328 newcpu = cpumask_any_and(desc->affinity, 329 cpu_online_mask); 330 } 331 332 route_irq(desc, irq, newcpu); 333 } 334 } 335} 336#endif 337