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 22 atomic_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 */ 29 void 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 */ 39 static 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 53 int 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 struct irq_data *data; 60 struct irq_chip *chip; 61 62 if (i > nr_irqs) 63 return 0; 64 65 for (prec = 3, j = 1000; prec < 10 && j <= nr_irqs; ++prec) 66 j *= 10; 67 68 if (i == nr_irqs) 69 return show_other_interrupts(p, prec); 70 71 if (i == 0) { 72 seq_printf(p, "%*s", prec + 8, ""); 73 for_each_online_cpu(j) 74 seq_printf(p, "CPU%-8d", j); 75 seq_putc(p, '\n'); 76 } 77 78 desc = irq_to_desc(i); 79 if (!desc) 80 return 0; 81 82 data = irq_get_irq_data(i); 83 chip = irq_data_get_irq_chip(data); 84 85 raw_spin_lock_irqsave(&desc->lock, flags); 86 for_each_online_cpu(j) 87 any_count |= kstat_irqs_cpu(i, j); 88 action = desc->action; 89 if (!action && !any_count) 90 goto out; 91 92 seq_printf(p, "%*d: ", prec, i); 93 for_each_online_cpu(j) 94 seq_printf(p, "%10u ", kstat_irqs_cpu(i, j)); 95 seq_printf(p, " %14s", chip->name); 96 seq_printf(p, "-%-8s", desc->name); 97 98 if (action) { 99 seq_printf(p, " %s", action->name); 100 while ((action = action->next) != NULL) 101 seq_printf(p, ", %s", action->name); 102 } 103 104 seq_putc(p, '\n'); 105 out: 106 raw_spin_unlock_irqrestore(&desc->lock, flags); 107 return 0; 108 } 109 #endif 110 111 #ifdef CONFIG_IRQSTACKS 112 /* 113 * per-CPU IRQ handling contexts (thread information and stack) 114 */ 115 union irq_ctx { 116 struct thread_info tinfo; 117 u32 stack[THREAD_SIZE/sizeof(u32)]; 118 }; 119 120 static union irq_ctx *hardirq_ctx[NR_CPUS] __read_mostly; 121 static union irq_ctx *softirq_ctx[NR_CPUS] __read_mostly; 122 123 static char softirq_stack[NR_CPUS * THREAD_SIZE] __page_aligned_bss; 124 static char hardirq_stack[NR_CPUS * THREAD_SIZE] __page_aligned_bss; 125 126 static inline void handle_one_irq(unsigned int irq) 127 { 128 union irq_ctx *curctx, *irqctx; 129 130 curctx = (union irq_ctx *)current_thread_info(); 131 irqctx = hardirq_ctx[smp_processor_id()]; 132 133 /* 134 * this is where we switch to the IRQ stack. However, if we are 135 * already using the IRQ stack (because we interrupted a hardirq 136 * handler) we can't do that and just have to keep using the 137 * current stack (which is the irq stack already after all) 138 */ 139 if (curctx != irqctx) { 140 u32 *isp; 141 142 isp = (u32 *)((char *)irqctx + sizeof(*irqctx)); 143 irqctx->tinfo.task = curctx->tinfo.task; 144 irqctx->tinfo.previous_sp = current_stack_pointer; 145 146 /* 147 * Copy the softirq bits in preempt_count so that the 148 * softirq checks work in the hardirq context. 149 */ 150 irqctx->tinfo.preempt_count = 151 (irqctx->tinfo.preempt_count & ~SOFTIRQ_MASK) | 152 (curctx->tinfo.preempt_count & SOFTIRQ_MASK); 153 154 __asm__ __volatile__ ( 155 "mov %0, r4 \n" 156 "mov r15, r8 \n" 157 "jsr @%1 \n" 158 /* swith to the irq stack */ 159 " mov %2, r15 \n" 160 /* restore the stack (ring zero) */ 161 "mov r8, r15 \n" 162 : /* no outputs */ 163 : "r" (irq), "r" (generic_handle_irq), "r" (isp) 164 : "memory", "r0", "r1", "r2", "r3", "r4", 165 "r5", "r6", "r7", "r8", "t", "pr" 166 ); 167 } else 168 generic_handle_irq(irq); 169 } 170 171 /* 172 * allocate per-cpu stacks for hardirq and for softirq processing 173 */ 174 void irq_ctx_init(int cpu) 175 { 176 union irq_ctx *irqctx; 177 178 if (hardirq_ctx[cpu]) 179 return; 180 181 irqctx = (union irq_ctx *)&hardirq_stack[cpu * THREAD_SIZE]; 182 irqctx->tinfo.task = NULL; 183 irqctx->tinfo.exec_domain = NULL; 184 irqctx->tinfo.cpu = cpu; 185 irqctx->tinfo.preempt_count = HARDIRQ_OFFSET; 186 irqctx->tinfo.addr_limit = MAKE_MM_SEG(0); 187 188 hardirq_ctx[cpu] = irqctx; 189 190 irqctx = (union irq_ctx *)&softirq_stack[cpu * THREAD_SIZE]; 191 irqctx->tinfo.task = NULL; 192 irqctx->tinfo.exec_domain = NULL; 193 irqctx->tinfo.cpu = cpu; 194 irqctx->tinfo.preempt_count = 0; 195 irqctx->tinfo.addr_limit = MAKE_MM_SEG(0); 196 197 softirq_ctx[cpu] = irqctx; 198 199 printk("CPU %u irqstacks, hard=%p soft=%p\n", 200 cpu, hardirq_ctx[cpu], softirq_ctx[cpu]); 201 } 202 203 void irq_ctx_exit(int cpu) 204 { 205 hardirq_ctx[cpu] = NULL; 206 } 207 208 asmlinkage void do_softirq(void) 209 { 210 unsigned long flags; 211 struct thread_info *curctx; 212 union irq_ctx *irqctx; 213 u32 *isp; 214 215 if (in_interrupt()) 216 return; 217 218 local_irq_save(flags); 219 220 if (local_softirq_pending()) { 221 curctx = current_thread_info(); 222 irqctx = softirq_ctx[smp_processor_id()]; 223 irqctx->tinfo.task = curctx->task; 224 irqctx->tinfo.previous_sp = current_stack_pointer; 225 226 /* build the stack frame on the softirq stack */ 227 isp = (u32 *)((char *)irqctx + sizeof(*irqctx)); 228 229 __asm__ __volatile__ ( 230 "mov r15, r9 \n" 231 "jsr @%0 \n" 232 /* switch to the softirq stack */ 233 " mov %1, r15 \n" 234 /* restore the thread stack */ 235 "mov r9, r15 \n" 236 : /* no outputs */ 237 : "r" (__do_softirq), "r" (isp) 238 : "memory", "r0", "r1", "r2", "r3", "r4", 239 "r5", "r6", "r7", "r8", "r9", "r15", "t", "pr" 240 ); 241 242 /* 243 * Shouldnt happen, we returned above if in_interrupt(): 244 */ 245 WARN_ON_ONCE(softirq_count()); 246 } 247 248 local_irq_restore(flags); 249 } 250 #else 251 static inline void handle_one_irq(unsigned int irq) 252 { 253 generic_handle_irq(irq); 254 } 255 #endif 256 257 asmlinkage __irq_entry int do_IRQ(unsigned int irq, struct pt_regs *regs) 258 { 259 struct pt_regs *old_regs = set_irq_regs(regs); 260 261 irq_enter(); 262 263 irq = irq_demux(irq_lookup(irq)); 264 265 if (irq != NO_IRQ_IGNORE) { 266 handle_one_irq(irq); 267 irq_finish(irq); 268 } 269 270 irq_exit(); 271 272 set_irq_regs(old_regs); 273 274 return IRQ_HANDLED; 275 } 276 277 void __init init_IRQ(void) 278 { 279 plat_irq_setup(); 280 281 /* Perform the machine specific initialisation */ 282 if (sh_mv.mv_init_irq) 283 sh_mv.mv_init_irq(); 284 285 intc_finalize(); 286 287 irq_ctx_init(smp_processor_id()); 288 } 289 290 #ifdef CONFIG_SPARSE_IRQ 291 int __init arch_probe_nr_irqs(void) 292 { 293 nr_irqs = sh_mv.mv_nr_irqs; 294 return NR_IRQS_LEGACY; 295 } 296 #endif 297 298 #ifdef CONFIG_HOTPLUG_CPU 299 static void route_irq(struct irq_data *data, unsigned int irq, unsigned int cpu) 300 { 301 struct irq_desc *desc = irq_to_desc(irq); 302 struct irq_chip *chip = irq_data_get_irq_chip(data); 303 304 printk(KERN_INFO "IRQ%u: moving from cpu%u to cpu%u\n", 305 irq, data->node, cpu); 306 307 raw_spin_lock_irq(&desc->lock); 308 chip->irq_set_affinity(data, cpumask_of(cpu), false); 309 raw_spin_unlock_irq(&desc->lock); 310 } 311 312 /* 313 * The CPU has been marked offline. Migrate IRQs off this CPU. If 314 * the affinity settings do not allow other CPUs, force them onto any 315 * available CPU. 316 */ 317 void migrate_irqs(void) 318 { 319 unsigned int irq, cpu = smp_processor_id(); 320 321 for_each_active_irq(irq) { 322 struct irq_data *data = irq_get_irq_data(irq); 323 324 if (data->node == cpu) { 325 unsigned int newcpu = cpumask_any_and(data->affinity, 326 cpu_online_mask); 327 if (newcpu >= nr_cpu_ids) { 328 if (printk_ratelimit()) 329 printk(KERN_INFO "IRQ%u no longer affine to CPU%u\n", 330 irq, cpu); 331 332 cpumask_setall(data->affinity); 333 newcpu = cpumask_any_and(data->affinity, 334 cpu_online_mask); 335 } 336 337 route_irq(data, irq, newcpu); 338 } 339 } 340 } 341 #endif 342