arch/mn10300/kernel/irq.c

   1 /* MN10300 Arch-specific interrupt handling
   2  *
   3  * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
   4  * Written by David Howells (dhowells@redhat.com)
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public Licence
   8  * as published by the Free Software Foundation; either version
   9  * 2 of the Licence, or (at your option) any later version.
  10  */
  11 #include <linux/module.h>
  12 #include <linux/interrupt.h>
  13 #include <linux/kernel_stat.h>
  14 #include <linux/seq_file.h>
  15 #include <linux/cpumask.h>
  16 #include <asm/setup.h>
  17 #include <asm/serial-regs.h>
  18
  19 #ifdef CONFIG_SMP
  20 #undef  GxICR
  21 #define GxICR(X) CROSS_GxICR(X, irq_affinity_online[X])
  22
  23 #undef  GxICR_u8
  24 #define GxICR_u8(X) CROSS_GxICR_u8(X, irq_affinity_online[X])
  25 #endif /* CONFIG_SMP */
  26
  27 unsigned long __mn10300_irq_enabled_epsw[NR_CPUS] __cacheline_aligned_in_smp = {
  28         [0 ... NR_CPUS - 1] = EPSW_IE | EPSW_IM_7
  29 };
  30 EXPORT_SYMBOL(__mn10300_irq_enabled_epsw);
  31
  32 #ifdef CONFIG_SMP
  33 static char irq_affinity_online[NR_IRQS] = {
  34         [0 ... NR_IRQS - 1] = 0
  35 };
  36
  37 #define NR_IRQ_WORDS    ((NR_IRQS + 31) / 32)
  38 static unsigned long irq_affinity_request[NR_IRQ_WORDS] = {
  39         [0 ... NR_IRQ_WORDS - 1] = 0
  40 };
  41 #endif  /* CONFIG_SMP */
  42
  43 atomic_t irq_err_count;
  44
  45 /*
  46  * MN10300 interrupt controller operations
  47  */
  48 static void mn10300_cpupic_ack(unsigned int irq)
  49 {
  50         unsigned long flags;
  51         u16 tmp;
  52
  53         flags = arch_local_cli_save();
  54         GxICR_u8(irq) = GxICR_DETECT;
  55         tmp = GxICR(irq);
  56         arch_local_irq_restore(flags);
  57 }
  58
  59 static void __mask_and_set_icr(unsigned int irq,
  60                                unsigned int mask, unsigned int set)
  61 {
  62         unsigned long flags;
  63         u16 tmp;
  64
  65         flags = arch_local_cli_save();
  66         tmp = GxICR(irq);
  67         GxICR(irq) = (tmp & mask) | set;
  68         tmp = GxICR(irq);
  69         arch_local_irq_restore(flags);
  70 }
  71
  72 static void mn10300_cpupic_mask(unsigned int irq)
  73 {
  74         __mask_and_set_icr(irq, GxICR_LEVEL, 0);
  75 }
  76
  77 static void mn10300_cpupic_mask_ack(unsigned int irq)
  78 {
  79 #ifdef CONFIG_SMP
  80         unsigned long flags;
  81         u16 tmp;
  82
  83         flags = arch_local_cli_save();
  84
  85         if (!test_and_clear_bit(irq, irq_affinity_request)) {
  86                 tmp = GxICR(irq);
  87                 GxICR(irq) = (tmp & GxICR_LEVEL) | GxICR_DETECT;
  88                 tmp = GxICR(irq);
  89         } else {
  90                 u16 tmp2;
  91                 tmp = GxICR(irq);
  92                 GxICR(irq) = (tmp & GxICR_LEVEL);
  93                 tmp2 = GxICR(irq);
  94
  95                 irq_affinity_online[irq] = any_online_cpu(*irq_desc[irq].affinity);
  96                 GxICR(irq) = (tmp & (GxICR_LEVEL | GxICR_ENABLE)) | GxICR_DETECT;
  97                 tmp = GxICR(irq);
  98         }
  99
 100         arch_local_irq_restore(flags);
 101 #else  /* CONFIG_SMP */
 102         __mask_and_set_icr(irq, GxICR_LEVEL, GxICR_DETECT);
 103 #endif /* CONFIG_SMP */
 104 }
 105
 106 static void mn10300_cpupic_unmask(unsigned int irq)
 107 {
 108         __mask_and_set_icr(irq, GxICR_LEVEL, GxICR_ENABLE);
 109 }
 110
 111 static void mn10300_cpupic_unmask_clear(unsigned int irq)
 112 {
 113         /* the MN10300 PIC latches its interrupt request bit, even after the
 114          * device has ceased to assert its interrupt line and the interrupt
 115          * channel has been disabled in the PIC, so for level-triggered
 116          * interrupts we need to clear the request bit when we re-enable */
 117 #ifdef CONFIG_SMP
 118         unsigned long flags;
 119         u16 tmp;
 120
 121         flags = arch_local_cli_save();
 122
 123         if (!test_and_clear_bit(irq, irq_affinity_request)) {
 124                 tmp = GxICR(irq);
 125                 GxICR(irq) = (tmp & GxICR_LEVEL) | GxICR_ENABLE | GxICR_DETECT;
 126                 tmp = GxICR(irq);
 127         } else {
 128                 tmp = GxICR(irq);
 129
 130                 irq_affinity_online[irq] = any_online_cpu(*irq_desc[irq].affinity);
 131                 GxICR(irq) = (tmp & GxICR_LEVEL) | GxICR_ENABLE | GxICR_DETECT;
 132                 tmp = GxICR(irq);
 133         }
 134
 135         arch_local_irq_restore(flags);
 136 #else  /* CONFIG_SMP */
 137         __mask_and_set_icr(irq, GxICR_LEVEL, GxICR_ENABLE | GxICR_DETECT);
 138 #endif /* CONFIG_SMP */
 139 }
 140
 141 #ifdef CONFIG_SMP
 142 static int
 143 mn10300_cpupic_setaffinity(unsigned int irq, const struct cpumask *mask)
 144 {
 145         unsigned long flags;
 146         int err;
 147
 148         flags = arch_local_cli_save();
 149
 150         /* check irq no */
 151         switch (irq) {
 152         case TMJCIRQ:
 153         case RESCHEDULE_IPI:
 154         case CALL_FUNC_SINGLE_IPI:
 155         case LOCAL_TIMER_IPI:
 156         case FLUSH_CACHE_IPI:
 157         case CALL_FUNCTION_NMI_IPI:
 158         case GDB_NMI_IPI:
 159 #ifdef CONFIG_MN10300_TTYSM0
 160         case SC0RXIRQ:
 161         case SC0TXIRQ:
 162 #ifdef CONFIG_MN10300_TTYSM0_TIMER8
 163         case TM8IRQ:
 164 #elif CONFIG_MN10300_TTYSM0_TIMER2
 165         case TM2IRQ:
 166 #endif /* CONFIG_MN10300_TTYSM0_TIMER8 */
 167 #endif /* CONFIG_MN10300_TTYSM0 */
 168
 169 #ifdef CONFIG_MN10300_TTYSM1
 170         case SC1RXIRQ:
 171         case SC1TXIRQ:
 172 #ifdef CONFIG_MN10300_TTYSM1_TIMER12
 173         case TM12IRQ:
 174 #elif CONFIG_MN10300_TTYSM1_TIMER9
 175         case TM9IRQ:
 176 #elif CONFIG_MN10300_TTYSM1_TIMER3
 177         case TM3IRQ:
 178 #endif /* CONFIG_MN10300_TTYSM1_TIMER12 */
 179 #endif /* CONFIG_MN10300_TTYSM1 */
 180
 181 #ifdef CONFIG_MN10300_TTYSM2
 182         case SC2RXIRQ:
 183         case SC2TXIRQ:
 184         case TM10IRQ:
 185 #endif /* CONFIG_MN10300_TTYSM2 */
 186                 err = -1;
 187                 break;
 188
 189         default:
 190                 set_bit(irq, irq_affinity_request);
 191                 err = 0;
 192                 break;
 193         }
 194
 195         arch_local_irq_restore(flags);
 196         return err;
 197 }
 198 #endif /* CONFIG_SMP */
 199
 200 /*
 201  * MN10300 PIC level-triggered IRQ handling.
 202  *
 203  * The PIC has no 'ACK' function per se.  It is possible to clear individual
 204  * channel latches, but each latch relatches whether or not the channel is
 205  * masked, so we need to clear the latch when we unmask the channel.
 206  *
 207  * Also for this reason, we don't supply an ack() op (it's unused anyway if
 208  * mask_ack() is provided), and mask_ack() just masks.
 209  */
 210 static struct irq_chip mn10300_cpu_pic_level = {
 211         .name           = "cpu_l",
 212         .disable        = mn10300_cpupic_mask,
 213         .enable         = mn10300_cpupic_unmask_clear,
 214         .ack            = NULL,
 215         .mask           = mn10300_cpupic_mask,
 216         .mask_ack       = mn10300_cpupic_mask,
 217         .unmask         = mn10300_cpupic_unmask_clear,
 218 #ifdef CONFIG_SMP
 219         .set_affinity   = mn10300_cpupic_setaffinity,
 220 #endif /* CONFIG_SMP */
 221 };
 222
 223 /*
 224  * MN10300 PIC edge-triggered IRQ handling.
 225  *
 226  * We use the latch clearing function of the PIC as the 'ACK' function.
 227  */
 228 static struct irq_chip mn10300_cpu_pic_edge = {
 229         .name           = "cpu_e",
 230         .disable        = mn10300_cpupic_mask,
 231         .enable         = mn10300_cpupic_unmask,
 232         .ack            = mn10300_cpupic_ack,
 233         .mask           = mn10300_cpupic_mask,
 234         .mask_ack       = mn10300_cpupic_mask_ack,
 235         .unmask         = mn10300_cpupic_unmask,
 236 #ifdef CONFIG_SMP
 237         .set_affinity   = mn10300_cpupic_setaffinity,
 238 #endif /* CONFIG_SMP */
 239 };
 240
 241 /*
 242  * 'what should we do if we get a hw irq event on an illegal vector'.
 243  * each architecture has to answer this themselves.
 244  */
 245 void ack_bad_irq(int irq)
 246 {
 247         printk(KERN_WARNING "unexpected IRQ trap at vector %02x\n", irq);
 248 }
 249
 250 /*
 251  * change the level at which an IRQ executes
 252  * - must not be called whilst interrupts are being processed!
 253  */
 254 void set_intr_level(int irq, u16 level)
 255 {
 256         BUG_ON(in_interrupt());
 257
 258         __mask_and_set_icr(irq, GxICR_ENABLE, level);
 259 }
 260
 261 void mn10300_intc_set_level(unsigned int irq, unsigned int level)
 262 {
 263         set_intr_level(irq, NUM2GxICR_LEVEL(level) & GxICR_LEVEL);
 264 }
 265
 266 void mn10300_intc_clear(unsigned int irq)
 267 {
 268         __mask_and_set_icr(irq, GxICR_LEVEL | GxICR_ENABLE, GxICR_DETECT);
 269 }
 270
 271 void mn10300_intc_set(unsigned int irq)
 272 {
 273         __mask_and_set_icr(irq, 0, GxICR_REQUEST | GxICR_DETECT);
 274 }
 275
 276 void mn10300_intc_enable(unsigned int irq)
 277 {
 278         mn10300_cpupic_unmask(irq);
 279 }
 280
 281 void mn10300_intc_disable(unsigned int irq)
 282 {
 283         mn10300_cpupic_mask(irq);
 284 }
 285
 286 /*
 287  * mark an interrupt to be ACK'd after interrupt handlers have been run rather
 288  * than before
 289  * - see Documentation/mn10300/features.txt
 290  */
 291 void mn10300_set_lateack_irq_type(int irq)
 292 {
 293         set_irq_chip_and_handler(irq, &mn10300_cpu_pic_level,
 294                                  handle_level_irq);
 295 }
 296
 297 /*
 298  * initialise the interrupt system
 299  */
 300 void __init init_IRQ(void)
 301 {
 302         int irq;
 303
 304         for (irq = 0; irq < NR_IRQS; irq++)
 305                 if (irq_desc[irq].chip == &no_irq_chip)
 306                         /* due to the PIC latching interrupt requests, even
 307                          * when the IRQ is disabled, IRQ_PENDING is superfluous
 308                          * and we can use handle_level_irq() for edge-triggered
 309                          * interrupts */
 310                         set_irq_chip_and_handler(irq, &mn10300_cpu_pic_edge,
 311                                                  handle_level_irq);
 312
 313         unit_init_IRQ();
 314 }
 315
 316 /*
 317  * handle normal device IRQs
 318  */
 319 asmlinkage void do_IRQ(void)
 320 {
 321         unsigned long sp, epsw, irq_disabled_epsw, old_irq_enabled_epsw;
 322         unsigned int cpu_id = smp_processor_id();
 323         int irq;
 324
 325         sp = current_stack_pointer();
 326         BUG_ON(sp - (sp & ~(THREAD_SIZE - 1)) < STACK_WARN);
 327
 328         /* make sure local_irq_enable() doesn't muck up the interrupt priority
 329          * setting in EPSW */
 330         old_irq_enabled_epsw = __mn10300_irq_enabled_epsw[cpu_id];
 331         local_save_flags(epsw);
 332         __mn10300_irq_enabled_epsw[cpu_id] = EPSW_IE | (EPSW_IM & epsw);
 333         irq_disabled_epsw = EPSW_IE | MN10300_CLI_LEVEL;
 334
 335 #ifdef CONFIG_MN10300_WD_TIMER
 336         __IRQ_STAT(cpu_id, __irq_count)++;
 337 #endif
 338
 339         irq_enter();
 340
 341         for (;;) {
 342                 /* ask the interrupt controller for the next IRQ to process
 343                  * - the result we get depends on EPSW.IM
 344                  */
 345                 irq = IAGR & IAGR_GN;
 346                 if (!irq)
 347                         break;
 348
 349                 local_irq_restore(irq_disabled_epsw);
 350
 351                 generic_handle_irq(irq >> 2);
 352
 353                 /* restore IRQ controls for IAGR access */
 354                 local_irq_restore(epsw);
 355         }
 356
 357         __mn10300_irq_enabled_epsw[cpu_id] = old_irq_enabled_epsw;
 358
 359         irq_exit();
 360 }
 361
 362 /*
 363  * Display interrupt management information through /proc/interrupts
 364  */
 365 int show_interrupts(struct seq_file *p, void *v)
 366 {
 367         int i = *(loff_t *) v, j, cpu;
 368         struct irqaction *action;
 369         unsigned long flags;
 370
 371         switch (i) {
 372                 /* display column title bar naming CPUs */
 373         case 0:
 374                 seq_printf(p, "           ");
 375                 for (j = 0; j < NR_CPUS; j++)
 376                         if (cpu_online(j))
 377                                 seq_printf(p, "CPU%d       ", j);
 378                 seq_putc(p, '\n');
 379                 break;
 380
 381                 /* display information rows, one per active CPU */
 382         case 1 ... NR_IRQS - 1:
 383                 raw_spin_lock_irqsave(&irq_desc[i].lock, flags);
 384
 385                 action = irq_desc[i].action;
 386                 if (action) {
 387                         seq_printf(p, "%3d: ", i);
 388                         for_each_present_cpu(cpu)
 389                                 seq_printf(p, "%10u ", kstat_irqs_cpu(i, cpu));
 390                         seq_printf(p, " %14s.%u", irq_desc[i].chip->name,
 391                                    (GxICR(i) & GxICR_LEVEL) >>
 392                                    GxICR_LEVEL_SHIFT);
 393                         seq_printf(p, "  %s", action->name);
 394
 395                         for (action = action->next;
 396                              action;
 397                              action = action->next)
 398                                 seq_printf(p, ", %s", action->name);
 399
 400                         seq_putc(p, '\n');
 401                 }
 402
 403                 raw_spin_unlock_irqrestore(&irq_desc[i].lock, flags);
 404                 break;
 405
 406                 /* polish off with NMI and error counters */
 407         case NR_IRQS:
 408 #ifdef CONFIG_MN10300_WD_TIMER
 409                 seq_printf(p, "NMI: ");
 410                 for (j = 0; j < NR_CPUS; j++)
 411                         if (cpu_online(j))
 412                                 seq_printf(p, "%10u ", nmi_count(j));
 413                 seq_putc(p, '\n');
 414 #endif
 415
 416                 seq_printf(p, "ERR: %10u\n", atomic_read(&irq_err_count));
 417                 break;
 418         }
 419
 420         return 0;
 421 }
 422
 423 #ifdef CONFIG_HOTPLUG_CPU
 424 void migrate_irqs(void)
 425 {
 426         irq_desc_t *desc;
 427         int irq;
 428         unsigned int self, new;
 429         unsigned long flags;
 430
 431         self = smp_processor_id();
 432         for (irq = 0; irq < NR_IRQS; irq++) {
 433                 desc = irq_desc + irq;
 434
 435                 if (desc->status == IRQ_PER_CPU)
 436                         continue;
 437
 438                 if (cpu_isset(self, irq_desc[irq].affinity) &&
 439                     !cpus_intersects(irq_affinity[irq], cpu_online_map)) {
 440                         int cpu_id;
 441                         cpu_id = first_cpu(cpu_online_map);
 442                         cpu_set(cpu_id, irq_desc[irq].affinity);
 443                 }
 444                 /* We need to operate irq_affinity_online atomically. */
 445                 arch_local_cli_save(flags);
 446                 if (irq_affinity_online[irq] == self) {
 447                         u16 x, tmp;
 448
 449                         x = CROSS_GxICR(irq, self);
 450                         CROSS_GxICR(irq, self) = x & GxICR_LEVEL;
 451                         tmp = CROSS_GxICR(irq, self);
 452
 453                         new = any_online_cpu(irq_desc[irq].affinity);
 454                         irq_affinity_online[irq] = new;
 455
 456                         CROSS_GxICR(irq, new) =
 457                                 (x & GxICR_LEVEL) | GxICR_DETECT;
 458                         tmp = CROSS_GxICR(irq, new);
 459
 460                         x &= GxICR_LEVEL | GxICR_ENABLE;
 461                         if (CROSS_GxICR(irq, self) & GxICR_REQUEST)
 462                                 x |= GxICR_REQUEST | GxICR_DETECT;
 463                         CROSS_GxICR(irq, new) = x;
 464                         tmp = CROSS_GxICR(irq, new);
 465                 }
 466                 arch_local_irq_restore(flags);
 467         }
 468 }
 469 #endif /* CONFIG_HOTPLUG_CPU */