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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 | /* * arch/s390/kernel/irq.c * * S390 version * Copyright (C) 1999,2000 IBM Deutschland Entwicklung GmbH, IBM Corporation * Author(s): Ingo Adlung (adlung@de.ibm.com) * * Derived from "arch/i386/kernel/irq.c" * Copyright (C) 1992, 1999 Linus Torvalds, Ingo Molnar * * S/390 I/O interrupt processing and I/O request processing is * implemented in arch/s390/kernel/s390io.c */ #include <linux/module.h> #include <linux/config.h> #include <linux/ptrace.h> #include <linux/errno.h> #include <linux/kernel_stat.h> #include <linux/signal.h> #include <linux/sched.h> #include <linux/ioport.h> #include <linux/interrupt.h> #include <linux/timex.h> #include <linux/malloc.h> #include <linux/string.h> #include <linux/random.h> #include <linux/smp.h> #include <linux/threads.h> #include <linux/smp_lock.h> #include <linux/init.h> #include <asm/system.h> #include <asm/io.h> #include <asm/irq.h> #include <asm/bitops.h> #include <asm/smp.h> #include <asm/pgtable.h> #include <asm/delay.h> #include <asm/lowcore.h> void s390_init_IRQ ( void ); void s390_free_irq ( unsigned int irq, void *dev_id); int s390_request_irq( unsigned int irq, void (*handler)(int, void *, struct pt_regs *), unsigned long irqflags, const char *devname, void *dev_id); #if 0 /* * The following vectors are part of the Linux architecture, there * is no hardware IRQ pin equivalent for them, they are triggered * through the ICC by us (IPIs), via smp_message_pass(): */ BUILD_SMP_INTERRUPT(reschedule_interrupt) BUILD_SMP_INTERRUPT(invalidate_interrupt) BUILD_SMP_INTERRUPT(stop_cpu_interrupt) BUILD_SMP_INTERRUPT(mtrr_interrupt) BUILD_SMP_INTERRUPT(spurious_interrupt) #endif #if 0 int get_irq_list(char *buf) { int i, j; struct irqaction * action; char *p = buf; p += sprintf(p, " "); for (j=0; j<smp_num_cpus; j++) p += sprintf(p, "CPU%d ",j); *p++ = '\n'; for (i = 0 ; i < NR_IRQS ; i++) { if (ioinfo[i] == INVALID_STORAGE_AREA) continue; action = ioinfo[i]->irq_desc.action; if (!action) continue; p += sprintf(p, "%3d: ",i); #ifndef CONFIG_SMP p += sprintf(p, "%10u ", kstat_irqs(i)); #else for (j=0; j<smp_num_cpus; j++) p += sprintf( p, "%10u ", kstat.irqs[cpu_logical_map(j)][i]); #endif p += sprintf(p, " %14s", ioinfo[i]->irq_desc.handler->typename); p += sprintf(p, " %s", action->name); for (action=action->next; action; action = action->next) { p += sprintf(p, ", %s", action->name); } /* endfor */ *p++ = '\n'; } /* endfor */ p += sprintf(p, "NMI: %10u\n", nmi_counter); #ifdef CONFIG_SMP p += sprintf(p, "IPI: %10u\n", atomic_read(&ipi_count)); #endif return p - buf; } #endif /* * Global interrupt locks for SMP. Allow interrupts to come in on any * CPU, yet make cli/sti act globally to protect critical regions.. */ #ifdef CONFIG_SMP atomic_t global_irq_holder = ATOMIC_INIT(NO_PROC_ID); atomic_t global_irq_lock = ATOMIC_INIT(0); atomic_t global_irq_count = ATOMIC_INIT(0); atomic_t global_bh_count; /* * "global_cli()" is a special case, in that it can hold the * interrupts disabled for a longish time, and also because * we may be doing TLB invalidates when holding the global * IRQ lock for historical reasons. Thus we may need to check * SMP invalidate events specially by hand here (but not in * any normal spinlocks) * * Thankfully we don't need this as we can deliver flush tlbs with * interrupts disabled DJB :-) */ #define check_smp_invalidate(cpu) static void show(char * str) { int i; unsigned long *stack; int cpu = smp_processor_id(); printk("\n%s, CPU %d:\n", str, cpu); printk("irq: %d [%d]\n", atomic_read(&global_irq_count),local_irq_count(smp_processor_id())); printk("bh: %d [%d]\n", atomic_read(&global_bh_count),local_bh_count(smp_processor_id())); stack = (unsigned long *) &str; for (i = 40; i ; i--) { unsigned long x = *++stack; if (x > (unsigned long) &init_task_union && x < (unsigned long) &vsprintf) { printk("<[%08lx]> ", x); } } } #define MAXCOUNT 100000000 static inline void wait_on_bh(void) { int count = MAXCOUNT; do { if (!--count) { show("wait_on_bh"); count = ~0; } /* nothing .. wait for the other bh's to go away */ } while (atomic_read(&global_bh_count) != 0); } static inline void wait_on_irq(int cpu) { int count = MAXCOUNT; for (;;) { /* * Wait until all interrupts are gone. Wait * for bottom half handlers unless we're * already executing in one.. */ if (!atomic_read(&global_irq_count)) { if (local_bh_count(cpu)|| !atomic_read(&global_bh_count)) break; } /* Duh, we have to loop. Release the lock to avoid deadlocks */ atomic_set(&global_irq_lock, 0); for (;;) { if (!--count) { show("wait_on_irq"); count = ~0; } __sti(); SYNC_OTHER_CORES(cpu); __cli(); check_smp_invalidate(cpu); if (atomic_read(&global_irq_count)) continue; if (atomic_read(&global_irq_lock)) continue; if (!local_bh_count(cpu) && atomic_read(&global_bh_count)) continue; if (!atomic_compare_and_swap(0, 1, &global_irq_lock)) break; } } } /* * This is called when we want to synchronize with * bottom half handlers. We need to wait until * no other CPU is executing any bottom half handler. * * Don't wait if we're already running in an interrupt * context or are inside a bh handler. */ void synchronize_bh(void) { if (atomic_read(&global_bh_count) && !in_interrupt()) wait_on_bh(); } /* * This is called when we want to synchronize with * interrupts. We may for example tell a device to * stop sending interrupts: but to make sure there * are no interrupts that are executing on another * CPU we need to call this function. */ void synchronize_irq(void) { if (atomic_read(&global_irq_count)) { /* Stupid approach */ cli(); sti(); } } static inline void get_irqlock(int cpu) { if (atomic_compare_and_swap(0,1,&global_irq_lock) != 0) { /* do we already hold the lock? */ if ( cpu == atomic_read(&global_irq_holder)) return; /* Uhhuh.. Somebody else got it. Wait.. */ do { check_smp_invalidate(cpu); } while (atomic_compare_and_swap(0,1,&global_irq_lock) != 0); } /* * We also to make sure that nobody else is running * in an interrupt context. */ wait_on_irq(cpu); /* * Ok, finally.. */ atomic_set(&global_irq_holder,cpu); } #define EFLAGS_I_SHIFT 57 /* * A global "cli()" while in an interrupt context * turns into just a local cli(). Interrupts * should use spinlocks for the (very unlikely) * case that they ever want to protect against * each other. * * If we already have local interrupts disabled, * this will not turn a local disable into a * global one (problems with spinlocks: this makes * save_flags+cli+sti usable inside a spinlock). */ void __global_cli(void) { unsigned long flags; __save_flags(flags); if (flags & (1UL << EFLAGS_I_SHIFT)) { int cpu = smp_processor_id(); __cli(); if (!in_irq()) get_irqlock(cpu); } } void __global_sti(void) { if (!in_irq()) release_irqlock(smp_processor_id()); __sti(); } /* * SMP flags value to restore to: * 0 - global cli * 1 - global sti * 2 - local cli * 3 - local sti */ unsigned long __global_save_flags(void) { int retval; int local_enabled; unsigned long flags; __save_flags(flags); local_enabled = (flags >> EFLAGS_I_SHIFT) & 1; /* default to local */ retval = 2 + local_enabled; /* check for global flags if we're not in an interrupt */ if (!in_irq()) { if (local_enabled) retval = 1; if (atomic_read(&global_irq_holder)== smp_processor_id()) retval = 0; } return retval; } void __global_restore_flags(unsigned long flags) { switch (flags) { case 0: __global_cli(); break; case 1: __global_sti(); break; case 2: __cli(); break; case 3: __sti(); break; default: printk("global_restore_flags: %08lx (%08lx)\n", flags, (&flags)[-1]); } } #endif void __init init_IRQ(void) { s390_init_IRQ(); } void free_irq(unsigned int irq, void *dev_id) { s390_free_irq( irq, dev_id); } int request_irq( unsigned int irq, void (*handler)(int, void *, struct pt_regs *), unsigned long irqflags, const char *devname, void *dev_id) { return( s390_request_irq( irq, handler, irqflags, devname, dev_id ) ); } void init_irq_proc(void) { /* For now, nothing... */ } EXPORT_SYMBOL(__global_cli); EXPORT_SYMBOL(__global_sti); EXPORT_SYMBOL(__global_save_flags); EXPORT_SYMBOL(__global_restore_flags); EXPORT_SYMBOL(global_bh_lock); |