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                         cpumask_any_and(d->affinity, cpu_online_mask);
  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] = cpumask_any_and(d->affinity,
 128                                                            cpu_online_mask);
 129                 CROSS_GxICR(irq, irq_affinity_online[irq]) = (tmp & GxICR_LEVEL) | GxICR_ENABLE | GxICR_DETECT;
 130                 tmp = CROSS_GxICR(irq, irq_affinity_online[irq]);
 131         }
 132
 133         arch_local_irq_restore(flags);
 134 #else  /* CONFIG_SMP */
 135         __mask_and_set_icr(irq, GxICR_LEVEL, GxICR_ENABLE | GxICR_DETECT);
 136 #endif /* CONFIG_SMP */
 137 }
 138
 139 #ifdef CONFIG_SMP
 140 static int
 141 mn10300_cpupic_setaffinity(struct irq_data *d, const struct cpumask *mask,
 142                            bool force)
 143 {
 144         unsigned long flags;
 145         int err;
 146
 147         flags = arch_local_cli_save();
 148
 149         /* check irq no */
 150         switch (d->irq) {
 151         case TMJCIRQ:
 152         case RESCHEDULE_IPI:
 153         case CALL_FUNC_SINGLE_IPI:
 154         case LOCAL_TIMER_IPI:
 155         case FLUSH_CACHE_IPI:
 156         case CALL_FUNCTION_NMI_IPI:
 157         case DEBUGGER_NMI_IPI:
 158 #ifdef CONFIG_MN10300_TTYSM0
 159         case SC0RXIRQ:
 160         case SC0TXIRQ:
 161 #ifdef CONFIG_MN10300_TTYSM0_TIMER8
 162         case TM8IRQ:
 163 #elif CONFIG_MN10300_TTYSM0_TIMER2
 164         case TM2IRQ:
 165 #endif /* CONFIG_MN10300_TTYSM0_TIMER8 */
 166 #endif /* CONFIG_MN10300_TTYSM0 */
 167
 168 #ifdef CONFIG_MN10300_TTYSM1
 169         case SC1RXIRQ:
 170         case SC1TXIRQ:
 171 #ifdef CONFIG_MN10300_TTYSM1_TIMER12
 172         case TM12IRQ:
 173 #elif CONFIG_MN10300_TTYSM1_TIMER9
 174         case TM9IRQ:
 175 #elif CONFIG_MN10300_TTYSM1_TIMER3
 176         case TM3IRQ:
 177 #endif /* CONFIG_MN10300_TTYSM1_TIMER12 */
 178 #endif /* CONFIG_MN10300_TTYSM1 */
 179
 180 #ifdef CONFIG_MN10300_TTYSM2
 181         case SC2RXIRQ:
 182         case SC2TXIRQ:
 183         case TM10IRQ:
 184 #endif /* CONFIG_MN10300_TTYSM2 */
 185                 err = -1;
 186                 break;
 187
 188         default:
 189                 set_bit(d->irq, irq_affinity_request);
 190                 err = 0;
 191                 break;
 192         }
 193
 194         arch_local_irq_restore(flags);
 195         return err;
 196 }
 197 #endif /* CONFIG_SMP */
 198
 199 /*
 200  * MN10300 PIC level-triggered IRQ handling.
 201  *
 202  * The PIC has no 'ACK' function per se.  It is possible to clear individual
 203  * channel latches, but each latch relatches whether or not the channel is
 204  * masked, so we need to clear the latch when we unmask the channel.
 205  *
 206  * Also for this reason, we don't supply an ack() op (it's unused anyway if
 207  * mask_ack() is provided), and mask_ack() just masks.
 208  */
 209 static struct irq_chip mn10300_cpu_pic_level = {
 210         .name                   = "cpu_l",
 211         .irq_disable            = mn10300_cpupic_mask,
 212         .irq_enable             = mn10300_cpupic_unmask_clear,
 213         .irq_ack                = NULL,
 214         .irq_mask               = mn10300_cpupic_mask,
 215         .irq_mask_ack           = mn10300_cpupic_mask,
 216         .irq_unmask             = mn10300_cpupic_unmask_clear,
 217 #ifdef CONFIG_SMP
 218         .irq_set_affinity       = mn10300_cpupic_setaffinity,
 219 #endif
 220 };
 221
 222 /*
 223  * MN10300 PIC edge-triggered IRQ handling.
 224  *
 225  * We use the latch clearing function of the PIC as the 'ACK' function.
 226  */
 227 static struct irq_chip mn10300_cpu_pic_edge = {
 228         .name                   = "cpu_e",
 229         .irq_disable            = mn10300_cpupic_mask,
 230         .irq_enable             = mn10300_cpupic_unmask,
 231         .irq_ack                = mn10300_cpupic_ack,
 232         .irq_mask               = mn10300_cpupic_mask,
 233         .irq_mask_ack           = mn10300_cpupic_mask_ack,
 234         .irq_unmask             = mn10300_cpupic_unmask,
 235 #ifdef CONFIG_SMP
 236         .irq_set_affinity       = mn10300_cpupic_setaffinity,
 237 #endif
 238 };
 239
 240 /*
 241  * 'what should we do if we get a hw irq event on an illegal vector'.
 242  * each architecture has to answer this themselves.
 243  */
 244 void ack_bad_irq(int irq)
 245 {
 246         printk(KERN_WARNING "unexpected IRQ trap at vector %02x\n", irq);
 247 }
 248
 249 /*
 250  * change the level at which an IRQ executes
 251  * - must not be called whilst interrupts are being processed!
 252  */
 253 void set_intr_level(int irq, u16 level)
 254 {
 255         BUG_ON(in_interrupt());
 256
 257         __mask_and_set_icr(irq, GxICR_ENABLE, level);
 258 }
 259
 260 /*
 261  * mark an interrupt to be ACK'd after interrupt handlers have been run rather
 262  * than before
 263  * - see Documentation/mn10300/features.txt
 264  */
 265 void mn10300_set_lateack_irq_type(int irq)
 266 {
 267         irq_set_chip_and_handler(irq, &mn10300_cpu_pic_level,
 268                                  handle_level_irq);
 269 }
 270
 271 /*
 272  * initialise the interrupt system
 273  */
 274 void __init init_IRQ(void)
 275 {
 276         int irq;
 277
 278         for (irq = 0; irq < NR_IRQS; irq++)
 279                 if (irq_get_chip(irq) == &no_irq_chip)
 280                         /* due to the PIC latching interrupt requests, even
 281                          * when the IRQ is disabled, IRQ_PENDING is superfluous
 282                          * and we can use handle_level_irq() for edge-triggered
 283                          * interrupts */
 284                         irq_set_chip_and_handler(irq, &mn10300_cpu_pic_edge,
 285                                                  handle_level_irq);
 286
 287         unit_init_IRQ();
 288 }
 289
 290 /*
 291  * handle normal device IRQs
 292  */
 293 asmlinkage void do_IRQ(void)
 294 {
 295         unsigned long sp, epsw, irq_disabled_epsw, old_irq_enabled_epsw;
 296         unsigned int cpu_id = smp_processor_id();
 297         int irq;
 298
 299         sp = current_stack_pointer();
 300         BUG_ON(sp - (sp & ~(THREAD_SIZE - 1)) < STACK_WARN);
 301
 302         /* make sure local_irq_enable() doesn't muck up the interrupt priority
 303          * setting in EPSW */
 304         old_irq_enabled_epsw = __mn10300_irq_enabled_epsw[cpu_id];
 305         local_save_flags(epsw);
 306         __mn10300_irq_enabled_epsw[cpu_id] = EPSW_IE | (EPSW_IM & epsw);
 307         irq_disabled_epsw = EPSW_IE | MN10300_CLI_LEVEL;
 308
 309 #ifdef CONFIG_MN10300_WD_TIMER
 310         __IRQ_STAT(cpu_id, __irq_count)++;
 311 #endif
 312
 313         irq_enter();
 314
 315         for (;;) {
 316                 /* ask the interrupt controller for the next IRQ to process
 317                  * - the result we get depends on EPSW.IM
 318                  */
 319                 irq = IAGR & IAGR_GN;
 320                 if (!irq)
 321                         break;
 322
 323                 local_irq_restore(irq_disabled_epsw);
 324
 325                 generic_handle_irq(irq >> 2);
 326
 327                 /* restore IRQ controls for IAGR access */
 328                 local_irq_restore(epsw);
 329         }
 330
 331         __mn10300_irq_enabled_epsw[cpu_id] = old_irq_enabled_epsw;
 332
 333         irq_exit();
 334 }
 335
 336 /*
 337  * Display interrupt management information through /proc/interrupts
 338  */
 339 int arch_show_interrupts(struct seq_file *p, int prec)
 340 {
 341 #ifdef CONFIG_MN10300_WD_TIMER
 342         int j;
 343
 344         seq_printf(p, "%*s: ", prec, "NMI");
 345         for (j = 0; j < NR_CPUS; j++)
 346                 if (cpu_online(j))
 347                         seq_printf(p, "%10u ", nmi_count(j));
 348         seq_putc(p, '\n');
 349 #endif
 350
 351         seq_printf(p, "%*s: ", prec, "ERR");
 352         seq_printf(p, "%10u\n", atomic_read(&irq_err_count));
 353         return 0;
 354 }
 355
 356 #ifdef CONFIG_HOTPLUG_CPU
 357 void migrate_irqs(void)
 358 {
 359         int irq;
 360         unsigned int self, new;
 361         unsigned long flags;
 362
 363         self = smp_processor_id();
 364         for (irq = 0; irq < NR_IRQS; irq++) {
 365                 struct irq_data *data = irq_get_irq_data(irq);
 366
 367                 if (irqd_is_per_cpu(data))
 368                         continue;
 369
 370                 if (cpumask_test_cpu(self, &data->affinity) &&
 371                     !cpumask_intersects(&irq_affinity[irq], cpu_online_mask)) {
 372                         int cpu_id;
 373                         cpu_id = cpumask_first(cpu_online_mask);
 374                         cpumask_set_cpu(cpu_id, &data->affinity);
 375                 }
 376                 /* We need to operate irq_affinity_online atomically. */
 377                 arch_local_cli_save(flags);
 378                 if (irq_affinity_online[irq] == self) {
 379                         u16 x, tmp;
 380
 381                         x = GxICR(irq);
 382                         GxICR(irq) = x & GxICR_LEVEL;
 383                         tmp = GxICR(irq);
 384
 385                         new = cpumask_any_and(&data->affinity,
 386                                               cpu_online_mask);
 387                         irq_affinity_online[irq] = new;
 388
 389                         CROSS_GxICR(irq, new) =
 390                                 (x & GxICR_LEVEL) | GxICR_DETECT;
 391                         tmp = CROSS_GxICR(irq, new);
 392
 393                         x &= GxICR_LEVEL | GxICR_ENABLE;
 394                         if (GxICR(irq) & GxICR_REQUEST)
 395                                 x |= GxICR_REQUEST | GxICR_DETECT;
 396                         CROSS_GxICR(irq, new) = x;
 397                         tmp = CROSS_GxICR(irq, new);
 398                 }
 399                 arch_local_irq_restore(flags);
 400         }
 401 }
 402 #endif /* CONFIG_HOTPLUG_CPU */