arch/m68k/kernel/ints.c

   1 /*
   2  * linux/arch/m68k/kernel/ints.c -- Linux/m68k general interrupt handling code
   3  *
   4  * This file is subject to the terms and conditions of the GNU General Public
   5  * License.  See the file COPYING in the main directory of this archive
   6  * for more details.
   7  *
   8  * 07/03/96: Timer initialization, and thus mach_sched_init(),
   9  *           removed from request_irq() and moved to init_time().
  10  *           We should therefore consider renaming our add_isr() and
  11  *           remove_isr() to request_irq() and free_irq()
  12  *           respectively, so they are compliant with the other
  13  *           architectures.                                     /Jes
  14  * 11/07/96: Changed all add_/remove_isr() to request_/free_irq() calls.
  15  *           Removed irq list support, if any machine needs an irq server
  16  *           it must implement this itself (as it's already done), instead
  17  *           only default handler are used with mach_default_handler.
  18  *           request_irq got some flags different from other architectures:
  19  *           - IRQ_FLG_REPLACE : Replace an existing handler (the default one
  20  *                               can be replaced without this flag)
  21  *           - IRQ_FLG_LOCK : handler can't be replaced
  22  *           There are other machine depending flags, see there
  23  *           If you want to replace a default handler you should know what
  24  *           you're doing, since it might handle different other irq sources
  25  *           which must be served                               /Roman Zippel
  26  */
  27
  28 #include <linux/module.h>
  29 #include <linux/types.h>
  30 #include <linux/sched.h>
  31 #include <linux/interrupt.h>
  32 #include <linux/kernel_stat.h>
  33 #include <linux/errno.h>
  34 #include <linux/init.h>
  35
  36 #include <asm/setup.h>
  37 #include <asm/system.h>
  38 #include <asm/irq.h>
  39 #include <asm/traps.h>
  40 #include <asm/page.h>
  41 #include <asm/machdep.h>
  42 #include <asm/cacheflush.h>
  43 #include <asm/irq_regs.h>
  44
  45 #ifdef CONFIG_Q40
  46 #include <asm/q40ints.h>
  47 #endif
  48
  49 extern u32 auto_irqhandler_fixup[];
  50 extern u32 user_irqhandler_fixup[];
  51 extern u16 user_irqvec_fixup[];
  52
  53 /* table for system interrupt handlers */
  54 static struct irq_node *irq_list[NR_IRQS];
  55 static struct irq_controller *irq_controller[NR_IRQS];
  56 static int irq_depth[NR_IRQS];
  57
  58 static int m68k_first_user_vec;
  59
  60 static struct irq_controller auto_irq_controller = {
  61         .name           = "auto",
  62         .lock           = __SPIN_LOCK_UNLOCKED(auto_irq_controller.lock),
  63         .startup        = m68k_irq_startup,
  64         .shutdown       = m68k_irq_shutdown,
  65 };
  66
  67 static struct irq_controller user_irq_controller = {
  68         .name           = "user",
  69         .lock           = __SPIN_LOCK_UNLOCKED(user_irq_controller.lock),
  70         .startup        = m68k_irq_startup,
  71         .shutdown       = m68k_irq_shutdown,
  72 };
  73
  74 #define NUM_IRQ_NODES 100
  75 static irq_node_t nodes[NUM_IRQ_NODES];
  76
  77 /*
  78  * void init_IRQ(void)
  79  *
  80  * Parameters:  None
  81  *
  82  * Returns:     Nothing
  83  *
  84  * This function should be called during kernel startup to initialize
  85  * the IRQ handling routines.
  86  */
  87
  88 void __init init_IRQ(void)
  89 {
  90         int i;
  91
  92         /* assembly irq entry code relies on this... */
  93         if (HARDIRQ_MASK != 0x00ff0000) {
  94                 extern void hardirq_mask_is_broken(void);
  95                 hardirq_mask_is_broken();
  96         }
  97
  98         for (i = IRQ_AUTO_1; i <= IRQ_AUTO_7; i++)
  99                 irq_controller[i] = &auto_irq_controller;
 100
 101         mach_init_IRQ();
 102 }
 103
 104 /**
 105  * m68k_setup_auto_interrupt
 106  * @handler: called from auto vector interrupts
 107  *
 108  * setup the handler to be called from auto vector interrupts instead of the
 109  * standard __m68k_handle_int(), it will be called with irq numbers in the range
 110  * from IRQ_AUTO_1 - IRQ_AUTO_7.
 111  */
 112 void __init m68k_setup_auto_interrupt(void (*handler)(unsigned int, struct pt_regs *))
 113 {
 114         if (handler)
 115                 *auto_irqhandler_fixup = (u32)handler;
 116         flush_icache();
 117 }
 118
 119 /**
 120  * m68k_setup_user_interrupt
 121  * @vec: first user vector interrupt to handle
 122  * @cnt: number of active user vector interrupts
 123  * @handler: called from user vector interrupts
 124  *
 125  * setup user vector interrupts, this includes activating the specified range
 126  * of interrupts, only then these interrupts can be requested (note: this is
 127  * different from auto vector interrupts). An optional handler can be installed
 128  * to be called instead of the default __m68k_handle_int(), it will be called
 129  * with irq numbers starting from IRQ_USER.
 130  */
 131 void __init m68k_setup_user_interrupt(unsigned int vec, unsigned int cnt,
 132                                       void (*handler)(unsigned int, struct pt_regs *))
 133 {
 134         int i;
 135
 136         BUG_ON(IRQ_USER + cnt >= NR_IRQS);
 137         m68k_first_user_vec = vec;
 138         for (i = 0; i < cnt; i++)
 139                 irq_controller[IRQ_USER + i] = &user_irq_controller;
 140         *user_irqvec_fixup = vec - IRQ_USER;
 141         if (handler)
 142                 *user_irqhandler_fixup = (u32)handler;
 143         flush_icache();
 144 }
 145
 146 /**
 147  * m68k_setup_irq_controller
 148  * @contr: irq controller which controls specified irq
 149  * @irq: first irq to be managed by the controller
 150  *
 151  * Change the controller for the specified range of irq, which will be used to
 152  * manage these irq. auto/user irq already have a default controller, which can
 153  * be changed as well, but the controller probably should use m68k_irq_startup/
 154  * m68k_irq_shutdown.
 155  */
 156 void m68k_setup_irq_controller(struct irq_controller *contr, unsigned int irq,
 157                                unsigned int cnt)
 158 {
 159         int i;
 160
 161         for (i = 0; i < cnt; i++)
 162                 irq_controller[irq + i] = contr;
 163 }
 164
 165 irq_node_t *new_irq_node(void)
 166 {
 167         irq_node_t *node;
 168         short i;
 169
 170         for (node = nodes, i = NUM_IRQ_NODES-1; i >= 0; node++, i--) {
 171                 if (!node->handler) {
 172                         memset(node, 0, sizeof(*node));
 173                         return node;
 174                 }
 175         }
 176
 177         printk ("new_irq_node: out of nodes\n");
 178         return NULL;
 179 }
 180
 181 int setup_irq(unsigned int irq, struct irq_node *node)
 182 {
 183         struct irq_controller *contr;
 184         struct irq_node **prev;
 185         unsigned long flags;
 186
 187         if (irq >= NR_IRQS || !(contr = irq_controller[irq])) {
 188                 printk("%s: Incorrect IRQ %d from %s\n",
 189                        __func__, irq, node->devname);
 190                 return -ENXIO;
 191         }
 192
 193         spin_lock_irqsave(&contr->lock, flags);
 194
 195         prev = irq_list + irq;
 196         if (*prev) {
 197                 /* Can't share interrupts unless both agree to */
 198                 if (!((*prev)->flags & node->flags & IRQF_SHARED)) {
 199                         spin_unlock_irqrestore(&contr->lock, flags);
 200                         return -EBUSY;
 201                 }
 202                 while (*prev)
 203                         prev = &(*prev)->next;
 204         }
 205
 206         if (!irq_list[irq]) {
 207                 if (contr->startup)
 208                         contr->startup(irq);
 209                 else
 210                         contr->enable(irq);
 211         }
 212         node->next = NULL;
 213         *prev = node;
 214
 215         spin_unlock_irqrestore(&contr->lock, flags);
 216
 217         return 0;
 218 }
 219
 220 int request_irq(unsigned int irq,
 221                 irq_handler_t handler,
 222                 unsigned long flags, const char *devname, void *dev_id)
 223 {
 224         struct irq_node *node;
 225         int res;
 226
 227         node = new_irq_node();
 228         if (!node)
 229                 return -ENOMEM;
 230
 231         node->handler = handler;
 232         node->flags   = flags;
 233         node->dev_id  = dev_id;
 234         node->devname = devname;
 235
 236         res = setup_irq(irq, node);
 237         if (res)
 238                 node->handler = NULL;
 239
 240         return res;
 241 }
 242
 243 EXPORT_SYMBOL(request_irq);
 244
 245 void free_irq(unsigned int irq, void *dev_id)
 246 {
 247         struct irq_controller *contr;
 248         struct irq_node **p, *node;
 249         unsigned long flags;
 250
 251         if (irq >= NR_IRQS || !(contr = irq_controller[irq])) {
 252                 printk("%s: Incorrect IRQ %d\n", __func__, irq);
 253                 return;
 254         }
 255
 256         spin_lock_irqsave(&contr->lock, flags);
 257
 258         p = irq_list + irq;
 259         while ((node = *p)) {
 260                 if (node->dev_id == dev_id)
 261                         break;
 262                 p = &node->next;
 263         }
 264
 265         if (node) {
 266                 *p = node->next;
 267                 node->handler = NULL;
 268         } else
 269                 printk("%s: Removing probably wrong IRQ %d\n",
 270                        __func__, irq);
 271
 272         if (!irq_list[irq]) {
 273                 if (contr->shutdown)
 274                         contr->shutdown(irq);
 275                 else
 276                         contr->disable(irq);
 277         }
 278
 279         spin_unlock_irqrestore(&contr->lock, flags);
 280 }
 281
 282 EXPORT_SYMBOL(free_irq);
 283
 284 void enable_irq(unsigned int irq)
 285 {
 286         struct irq_controller *contr;
 287         unsigned long flags;
 288
 289         if (irq >= NR_IRQS || !(contr = irq_controller[irq])) {
 290                 printk("%s: Incorrect IRQ %d\n",
 291                        __func__, irq);
 292                 return;
 293         }
 294
 295         spin_lock_irqsave(&contr->lock, flags);
 296         if (irq_depth[irq]) {
 297                 if (!--irq_depth[irq]) {
 298                         if (contr->enable)
 299                                 contr->enable(irq);
 300                 }
 301         } else
 302                 WARN_ON(1);
 303         spin_unlock_irqrestore(&contr->lock, flags);
 304 }
 305
 306 EXPORT_SYMBOL(enable_irq);
 307
 308 void disable_irq(unsigned int irq)
 309 {
 310         struct irq_controller *contr;
 311         unsigned long flags;
 312
 313         if (irq >= NR_IRQS || !(contr = irq_controller[irq])) {
 314                 printk("%s: Incorrect IRQ %d\n",
 315                        __func__, irq);
 316                 return;
 317         }
 318
 319         spin_lock_irqsave(&contr->lock, flags);
 320         if (!irq_depth[irq]++) {
 321                 if (contr->disable)
 322                         contr->disable(irq);
 323         }
 324         spin_unlock_irqrestore(&contr->lock, flags);
 325 }
 326
 327 EXPORT_SYMBOL(disable_irq);
 328
 329 void disable_irq_nosync(unsigned int irq) __attribute__((alias("disable_irq")));
 330
 331 EXPORT_SYMBOL(disable_irq_nosync);
 332
 333 int m68k_irq_startup(unsigned int irq)
 334 {
 335         if (irq <= IRQ_AUTO_7)
 336                 vectors[VEC_SPUR + irq] = auto_inthandler;
 337         else
 338                 vectors[m68k_first_user_vec + irq - IRQ_USER] = user_inthandler;
 339         return 0;
 340 }
 341
 342 void m68k_irq_shutdown(unsigned int irq)
 343 {
 344         if (irq <= IRQ_AUTO_7)
 345                 vectors[VEC_SPUR + irq] = bad_inthandler;
 346         else
 347                 vectors[m68k_first_user_vec + irq - IRQ_USER] = bad_inthandler;
 348 }
 349
 350
 351 /*
 352  * Do we need these probe functions on the m68k?
 353  *
 354  *  ... may be useful with ISA devices
 355  */
 356 unsigned long probe_irq_on (void)
 357 {
 358 #ifdef CONFIG_Q40
 359         if (MACH_IS_Q40)
 360                 return q40_probe_irq_on();
 361 #endif
 362         return 0;
 363 }
 364
 365 EXPORT_SYMBOL(probe_irq_on);
 366
 367 int probe_irq_off (unsigned long irqs)
 368 {
 369 #ifdef CONFIG_Q40
 370         if (MACH_IS_Q40)
 371                 return q40_probe_irq_off(irqs);
 372 #endif
 373         return 0;
 374 }
 375
 376 EXPORT_SYMBOL(probe_irq_off);
 377
 378 unsigned int irq_canonicalize(unsigned int irq)
 379 {
 380 #ifdef CONFIG_Q40
 381         if (MACH_IS_Q40 && irq == 11)
 382                 irq = 10;
 383 #endif
 384         return irq;
 385 }
 386
 387 EXPORT_SYMBOL(irq_canonicalize);
 388
 389 asmlinkage void m68k_handle_int(unsigned int irq)
 390 {
 391         struct irq_node *node;
 392         kstat_cpu(0).irqs[irq]++;
 393         node = irq_list[irq];
 394         do {
 395                 node->handler(irq, node->dev_id);
 396                 node = node->next;
 397         } while (node);
 398 }
 399
 400 asmlinkage void __m68k_handle_int(unsigned int irq, struct pt_regs *regs)
 401 {
 402         struct pt_regs *old_regs;
 403         old_regs = set_irq_regs(regs);
 404         m68k_handle_int(irq);
 405         set_irq_regs(old_regs);
 406 }
 407
 408 asmlinkage void handle_badint(struct pt_regs *regs)
 409 {
 410         kstat_cpu(0).irqs[0]++;
 411         printk("unexpected interrupt from %u\n", regs->vector);
 412 }
 413
 414 int show_interrupts(struct seq_file *p, void *v)
 415 {
 416         struct irq_controller *contr;
 417         struct irq_node *node;
 418         int i = *(loff_t *) v;
 419
 420         /* autovector interrupts */
 421         if (irq_list[i]) {
 422                 contr = irq_controller[i];
 423                 node = irq_list[i];
 424                 seq_printf(p, "%-8s %3u: %10u %s", contr->name, i, kstat_cpu(0).irqs[i], node->devname);
 425                 while ((node = node->next))
 426                         seq_printf(p, ", %s", node->devname);
 427                 seq_puts(p, "\n");
 428         }
 429         return 0;
 430 }
 431
 432 void init_irq_proc(void)
 433 {
 434         /* Insert /proc/irq driver here */
 435 }
 436