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 unsigned long __mn10300_irq_enabled_epsw[NR_CPUS] __cacheline_aligned_in_smp = {
  20         [0 ... NR_CPUS - 1] = EPSW_IE | EPSW_IM_7
  21 };
  22 EXPORT_SYMBOL(__mn10300_irq_enabled_epsw);
  23
  24 #ifdef CONFIG_SMP
  25 static char irq_affinity_online[NR_IRQS] = {
  26         [0 ... NR_IRQS - 1] = 0
  27 };
  28
  29 #define NR_IRQ_WORDS    ((NR_IRQS + 31) / 32)
  30 static unsigned long irq_affinity_request[NR_IRQ_WORDS] = {
  31         [0 ... NR_IRQ_WORDS - 1] = 0
  32 };
  33 #endif  /* CONFIG_SMP */
  34
  35 atomic_t irq_err_count;
  36
  37 /*
  38  * MN10300 interrupt controller operations
  39  */
  40 static void mn10300_cpupic_ack(struct irq_data *d)
  41 {
  42         unsigned int irq = d->irq;
  43         unsigned long flags;
  44         u16 tmp;
  45
  46         flags = arch_local_cli_save();
  47         GxICR_u8(irq) = GxICR_DETECT;
  48         tmp = GxICR(irq);
  49         arch_local_irq_restore(flags);
  50 }
  51
  52 static void __mask_and_set_icr(unsigned int irq,
  53                                unsigned int mask, unsigned int set)
  54 {
  55         unsigned long flags;
  56         u16 tmp;
  57
  58         flags = arch_local_cli_save();
  59         tmp = GxICR(irq);
  60         GxICR(irq) = (tmp & mask) | set;
  61         tmp = GxICR(irq);
  62         arch_local_irq_restore(flags);
  63 }
  64
  65 static void mn10300_cpupic_mask(struct irq_data *d)
  66 {
  67         __mask_and_set_icr(d->irq, GxICR_LEVEL, 0);
  68 }
  69
  70 static void mn10300_cpupic_mask_ack(struct irq_data *d)
  71 {
  72         unsigned int irq = d->irq;
  73 #ifdef CONFIG_SMP
  74         unsigned long flags;
  75         u16 tmp;
  76
  77         flags = arch_local_cli_save();
  78
  79         if (!test_and_clear_bit(irq, irq_affinity_request)) {
  80                 tmp = GxICR(irq);
  81                 GxICR(irq) = (tmp & GxICR_LEVEL) | GxICR_DETECT;
  82                 tmp = GxICR(irq);
  83         } else {
  84                 u16 tmp2;
  85                 tmp = GxICR(irq);
  86                 GxICR(irq) = (tmp & GxICR_LEVEL);
  87                 tmp2 = GxICR(irq);
  88
  89                 irq_affinity_online[irq] =
  90                         any_online_cpu(*d->affinity);
  91                 CROSS_GxICR(irq, irq_affinity_online[irq]) =
  92                         (tmp & (GxICR_LEVEL | GxICR_ENABLE)) | GxICR_DETECT;
  93                 tmp = CROSS_GxICR(irq, irq_affinity_online[irq]);
  94         }
  95
  96         arch_local_irq_restore(flags);
  97 #else  /* CONFIG_SMP */
  98         __mask_and_set_icr(irq, GxICR_LEVEL, GxICR_DETECT);
  99 #endif /* CONFIG_SMP */
 100 }
 101
 102 static void mn10300_cpupic_unmask(struct irq_data *d)
 103 {
 104         __mask_and_set_icr(d->irq, GxICR_LEVEL, GxICR_ENABLE);
 105 }
 106
 107 static void mn10300_cpupic_unmask_clear(struct irq_data *d)
 108 {
 109         unsigned int irq = d->irq;
 110         /* the MN10300 PIC latches its interrupt request bit, even after the
 111          * device has ceased to assert its interrupt line and the interrupt
 112          * channel has been disabled in the PIC, so for level-triggered
 113          * interrupts we need to clear the request bit when we re-enable */
 114 #ifdef CONFIG_SMP
 115         unsigned long flags;
 116         u16 tmp;
 117
 118         flags = arch_local_cli_save();
 119
 120         if (!test_and_clear_bit(irq, irq_affinity_request)) {
 121                 tmp = GxICR(irq);
 122                 GxICR(irq) = (tmp & GxICR_LEVEL) | GxICR_ENABLE | GxICR_DETECT;
 123                 tmp = GxICR(irq);
 124         } else {
 125                 tmp = GxICR(irq);
 126
 127                 irq_affinity_online[irq] = any_online_cpu(*d->affinity);
 128                 CROSS_GxICR(irq, irq_affinity_online[irq]) = (tmp & GxICR_LEVEL) | GxICR_ENABLE | GxICR_DETECT;
 129                 tmp = CROSS_GxICR(irq, irq_affinity_online[irq]);
 130         }
 131
 132         arch_local_irq_restore(flags);
 133 #else  /* CONFIG_SMP */
 134         __mask_and_set_icr(irq, GxICR_LEVEL, GxICR_ENABLE | GxICR_DETECT);
 135 #endif /* CONFIG_SMP */
 136 }
 137
 138 #ifdef CONFIG_SMP
 139 static int
 140 mn10300_cpupic_setaffinity(struct irq_data *d, const struct cpumask *mask,
 141                            bool force)
 142 {
 143         unsigned long flags;
 144         int err;
 145
 146         flags = arch_local_cli_save();
 147
 148         /* check irq no */
 149         switch (d->irq) {
 150         case TMJCIRQ:
 151         case RESCHEDULE_IPI:
 152         case CALL_FUNC_SINGLE_IPI:
 153         case LOCAL_TIMER_IPI:
 154         case FLUSH_CACHE_IPI:
 155         case CALL_FUNCTION_NMI_IPI:
 156         case DEBUGGER_NMI_IPI:
 157 #ifdef CONFIG_MN10300_TTYSM0
 158         case SC0RXIRQ:
 159         case SC0TXIRQ:
 160 #ifdef CONFIG_MN10300_TTYSM0_TIMER8
 161         case TM8IRQ:
 162 #elif CONFIG_MN10300_TTYSM0_TIMER2
 163         case TM2IRQ:
 164 #endif /* CONFIG_MN10300_TTYSM0_TIMER8 */
 165 #endif /* CONFIG_MN10300_TTYSM0 */
 166
 167 #ifdef CONFIG_MN10300_TTYSM1
 168         case SC1RXIRQ:
 169         case SC1TXIRQ:
 170 #ifdef CONFIG_MN10300_TTYSM1_TIMER12
 171         case TM12IRQ:
 172 #elif CONFIG_MN10300_TTYSM1_TIMER9
 173         case TM9IRQ:
 174 #elif CONFIG_MN10300_TTYSM1_TIMER3
 175         case TM3IRQ:
 176 #endif /* CONFIG_MN10300_TTYSM1_TIMER12 */
 177 #endif /* CONFIG_MN10300_TTYSM1 */
 178
 179 #ifdef CONFIG_MN10300_TTYSM2
 180         case SC2RXIRQ:
 181         case SC2TXIRQ:
 182         case TM10IRQ:
 183 #endif /* CONFIG_MN10300_TTYSM2 */
 184                 err = -1;
 185                 break;
 186
 187         default:
 188                 set_bit(d->irq, irq_affinity_request);
 189                 err = 0;
 190                 break;
 191         }
 192
 193         arch_local_irq_restore(flags);
 194         return err;
 195 }
 196 #endif /* CONFIG_SMP */
 197
 198 /*
 199  * MN10300 PIC level-triggered IRQ handling.
 200  *
 201  * The PIC has no 'ACK' function per se.  It is possible to clear individual
 202  * channel latches, but each latch relatches whether or not the channel is
 203  * masked, so we need to clear the latch when we unmask the channel.
 204  *
 205  * Also for this reason, we don't supply an ack() op (it's unused anyway if
 206  * mask_ack() is provided), and mask_ack() just masks.
 207  */
 208 static struct irq_chip mn10300_cpu_pic_level = {
 209         .name                   = "cpu_l",
 210         .irq_disable            = mn10300_cpupic_mask,
 211         .irq_enable             = mn10300_cpupic_unmask_clear,
 212         .irq_ack                = NULL,
 213         .irq_mask               = mn10300_cpupic_mask,
 214         .irq_mask_ack           = mn10300_cpupic_mask,
 215         .irq_unmask             = mn10300_cpupic_unmask_clear,
 216 #ifdef CONFIG_SMP
 217         .irq_set_affinity       = mn10300_cpupic_setaffinity,
 218 #endif
 219 };
 220
 221 /*
 222  * MN10300 PIC edge-triggered IRQ handling.
 223  *
 224  * We use the latch clearing function of the PIC as the 'ACK' function.
 225  */
 226 static struct irq_chip mn10300_cpu_pic_edge = {
 227         .name                   = "cpu_e",
 228         .irq_disable            = mn10300_cpupic_mask,
 229         .irq_enable             = mn10300_cpupic_unmask,
 230         .irq_ack                = mn10300_cpupic_ack,
 231         .irq_mask               = mn10300_cpupic_mask,
 232         .irq_mask_ack           = mn10300_cpupic_mask_ack,
 233         .irq_unmask             = mn10300_cpupic_unmask,
 234 #ifdef CONFIG_SMP
 235         .irq_set_affinity       = mn10300_cpupic_setaffinity,
 236 #endif
 237 };
 238
 239 /*
 240  * 'what should we do if we get a hw irq event on an illegal vector'.
 241  * each architecture has to answer this themselves.
 242  */
 243 void ack_bad_irq(int irq)
 244 {
 245         printk(KERN_WARNING "unexpected IRQ trap at vector %02x\n", irq);
 246 }
 247
 248 /*
 249  * change the level at which an IRQ executes
 250  * - must not be called whilst interrupts are being processed!
 251  */
 252 void set_intr_level(int irq, u16 level)
 253 {
 254         BUG_ON(in_interrupt());
 255
 256         __mask_and_set_icr(irq, GxICR_ENABLE, level);
 257 }
 258
 259 /*
 260  * mark an interrupt to be ACK'd after interrupt handlers have been run rather
 261  * than before
 262  * - see Documentation/mn10300/features.txt
 263  */
 264 void mn10300_set_lateack_irq_type(int irq)
 265 {
 266         irq_set_chip_and_handler(irq, &mn10300_cpu_pic_level,
 267                                  handle_level_irq);
 268 }
 269
 270 /*
 271  * initialise the interrupt system
 272  */
 273 void __init init_IRQ(void)
 274 {
 275         int irq;
 276
 277         for (irq = 0; irq < NR_IRQS; irq++)
 278                 if (irq_get_chip(irq) == &no_irq_chip)
 279                         /* due to the PIC latching interrupt requests, even
 280                          * when the IRQ is disabled, IRQ_PENDING is superfluous
 281                          * and we can use handle_level_irq() for edge-triggered
 282                          * interrupts */
 283                         irq_set_chip_and_handler(irq, &mn10300_cpu_pic_edge,
 284                                                  handle_level_irq);
 285
 286         unit_init_IRQ();
 287 }
 288
 289 /*
 290  * handle normal device IRQs
 291  */
 292 asmlinkage void do_IRQ(void)
 293 {
 294         unsigned long sp, epsw, irq_disabled_epsw, old_irq_enabled_epsw;
 295         unsigned int cpu_id = smp_processor_id();
 296         int irq;
 297
 298         sp = current_stack_pointer();
 299         BUG_ON(sp - (sp & ~(THREAD_SIZE - 1)) < STACK_WARN);
 300
 301         /* make sure local_irq_enable() doesn't muck up the interrupt priority
 302          * setting in EPSW */
 303         old_irq_enabled_epsw = __mn10300_irq_enabled_epsw[cpu_id];
 304         local_save_flags(epsw);
 305         __mn10300_irq_enabled_epsw[cpu_id] = EPSW_IE | (EPSW_IM & epsw);
 306         irq_disabled_epsw = EPSW_IE | MN10300_CLI_LEVEL;
 307
 308 #ifdef CONFIG_MN10300_WD_TIMER
 309         __IRQ_STAT(cpu_id, __irq_count)++;
 310 #endif
 311
 312         irq_enter();
 313
 314         for (;;) {
 315                 /* ask the interrupt controller for the next IRQ to process
 316                  * - the result we get depends on EPSW.IM
 317                  */
 318                 irq = IAGR & IAGR_GN;
 319                 if (!irq)
 320                         break;
 321
 322                 local_irq_restore(irq_disabled_epsw);
 323
 324                 generic_handle_irq(irq >> 2);
 325
 326                 /* restore IRQ controls for IAGR access */
 327                 local_irq_restore(epsw);
 328         }
 329
 330         __mn10300_irq_enabled_epsw[cpu_id] = old_irq_enabled_epsw;
 331
 332         irq_exit();
 333 }
 334
 335 /*
 336  * Display interrupt management information through /proc/interrupts
 337  */
 338 int arch_show_interrupts(struct seq_file *p, int prec)
 339 {
 340 #ifdef CONFIG_MN10300_WD_TIMER
 341         int j;
 342
 343         seq_printf(p, "%*s: ", prec, "NMI");
 344         for (j = 0; j < NR_CPUS; j++)
 345                 if (cpu_online(j))
 346                         seq_printf(p, "%10u ", nmi_count(j));
 347         seq_putc(p, '\n');
 348 #endif
 349
 350         seq_printf(p, "%*s: ", prec, "ERR");
 351         seq_printf(p, "%10u\n", atomic_read(&irq_err_count));
 352         return 0;
 353 }
 354
 355 #ifdef CONFIG_HOTPLUG_CPU
 356 void migrate_irqs(void)
 357 {
 358         int irq;
 359         unsigned int self, new;
 360         unsigned long flags;
 361
 362         self = smp_processor_id();
 363         for (irq = 0; irq < NR_IRQS; irq++) {
 364                 struct irq_data *data = irq_get_irq_data(irq);
 365
 366                 if (irqd_is_per_cpu(data))
 367                         continue;
 368
 369                 if (cpu_isset(self, data->affinity) &&
 370                     !cpus_intersects(irq_affinity[irq], cpu_online_map)) {
 371                         int cpu_id;
 372                         cpu_id = first_cpu(cpu_online_map);
 373                         cpu_set(cpu_id, data->affinity);
 374                 }
 375                 /* We need to operate irq_affinity_online atomically. */
 376                 arch_local_cli_save(flags);
 377                 if (irq_affinity_online[irq] == self) {
 378                         u16 x, tmp;
 379
 380                         x = GxICR(irq);
 381                         GxICR(irq) = x & GxICR_LEVEL;
 382                         tmp = GxICR(irq);
 383
 384                         new = any_online_cpu(data->affinity);
 385                         irq_affinity_online[irq] = new;
 386
 387                         CROSS_GxICR(irq, new) =
 388                                 (x & GxICR_LEVEL) | GxICR_DETECT;
 389                         tmp = CROSS_GxICR(irq, new);
 390
 391                         x &= GxICR_LEVEL | GxICR_ENABLE;
 392                         if (GxICR(irq) & GxICR_REQUEST)
 393                                 x |= GxICR_REQUEST | GxICR_DETECT;
 394                         CROSS_GxICR(irq, new) = x;
 395                         tmp = CROSS_GxICR(irq, new);
 396                 }
 397                 arch_local_irq_restore(flags);
 398         }
 399 }
 400 #endif /* CONFIG_HOTPLUG_CPU */