arch/um/kernel/irq.c

   1 /*
   2  * Copyright (C) 2000 Jeff Dike (jdike@karaya.com)
   3  * Licensed under the GPL
   4  * Derived (i.e. mostly copied) from arch/i386/kernel/irq.c:
   5  *      Copyright (C) 1992, 1998 Linus Torvalds, Ingo Molnar
   6  */
   7
   8 #include "linux/kernel.h"
   9 #include "linux/module.h"
  10 #include "linux/smp.h"
  11 #include "linux/kernel_stat.h"
  12 #include "linux/interrupt.h"
  13 #include "linux/random.h"
  14 #include "linux/slab.h"
  15 #include "linux/file.h"
  16 #include "linux/proc_fs.h"
  17 #include "linux/init.h"
  18 #include "linux/seq_file.h"
  19 #include "linux/profile.h"
  20 #include "linux/hardirq.h"
  21 #include "asm/irq.h"
  22 #include "asm/hw_irq.h"
  23 #include "asm/atomic.h"
  24 #include "asm/signal.h"
  25 #include "asm/system.h"
  26 #include "asm/errno.h"
  27 #include "asm/uaccess.h"
  28 #include "user_util.h"
  29 #include "kern_util.h"
  30 #include "irq_user.h"
  31 #include "irq_kern.h"
  32 #include "os.h"
  33 #include "sigio.h"
  34 #include "um_malloc.h"
  35 #include "misc_constants.h"
  36
  37 /*
  38  * Generic, controller-independent functions:
  39  */
  40
  41 int show_interrupts(struct seq_file *p, void *v)
  42 {
  43         int i = *(loff_t *) v, j;
  44         struct irqaction * action;
  45         unsigned long flags;
  46
  47         if (i == 0) {
  48                 seq_printf(p, "           ");
  49                 for_each_online_cpu(j)
  50                         seq_printf(p, "CPU%d       ",j);
  51                 seq_putc(p, '\n');
  52         }
  53
  54         if (i < NR_IRQS) {
  55                 spin_lock_irqsave(&irq_desc[i].lock, flags);
  56                 action = irq_desc[i].action;
  57                 if (!action)
  58                         goto skip;
  59                 seq_printf(p, "%3d: ",i);
  60 #ifndef CONFIG_SMP
  61                 seq_printf(p, "%10u ", kstat_irqs(i));
  62 #else
  63                 for_each_online_cpu(j)
  64                         seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
  65 #endif
  66                 seq_printf(p, " %14s", irq_desc[i].chip->typename);
  67                 seq_printf(p, "  %s", action->name);
  68
  69                 for (action=action->next; action; action = action->next)
  70                         seq_printf(p, ", %s", action->name);
  71
  72                 seq_putc(p, '\n');
  73 skip:
  74                 spin_unlock_irqrestore(&irq_desc[i].lock, flags);
  75         } else if (i == NR_IRQS) {
  76                 seq_putc(p, '\n');
  77         }
  78
  79         return 0;
  80 }
  81
  82 struct irq_fd *active_fds = NULL;
  83 static struct irq_fd **last_irq_ptr = &active_fds;
  84
  85 extern void free_irqs(void);
  86
  87 void sigio_handler(int sig, union uml_pt_regs *regs)
  88 {
  89         struct irq_fd *irq_fd;
  90         int n;
  91
  92         if (smp_sigio_handler())
  93                 return;
  94
  95         while (1) {
  96                 n = os_waiting_for_events(active_fds);
  97                 if (n <= 0) {
  98                         if(n == -EINTR) continue;
  99                         else break;
 100                 }
 101
 102                 for (irq_fd = active_fds; irq_fd != NULL; irq_fd = irq_fd->next) {
 103                         if (irq_fd->current_events != 0) {
 104                                 irq_fd->current_events = 0;
 105                                 do_IRQ(irq_fd->irq, regs);
 106                         }
 107                 }
 108         }
 109
 110         free_irqs();
 111 }
 112
 113 static DEFINE_SPINLOCK(irq_lock);
 114
 115 int activate_fd(int irq, int fd, int type, void *dev_id)
 116 {
 117         struct pollfd *tmp_pfd;
 118         struct irq_fd *new_fd, *irq_fd;
 119         unsigned long flags;
 120         int pid, events, err, n;
 121
 122         pid = os_getpid();
 123         err = os_set_fd_async(fd, pid);
 124         if (err < 0)
 125                 goto out;
 126
 127         new_fd = um_kmalloc(sizeof(*new_fd));
 128         err = -ENOMEM;
 129         if (new_fd == NULL)
 130                 goto out;
 131
 132         if (type == IRQ_READ)
 133                 events = UM_POLLIN | UM_POLLPRI;
 134         else
 135                 events = UM_POLLOUT;
 136         *new_fd = ((struct irq_fd) { .next              = NULL,
 137                                      .id                = dev_id,
 138                                      .fd                = fd,
 139                                      .type              = type,
 140                                      .irq               = irq,
 141                                      .pid               = pid,
 142                                      .events            = events,
 143                                      .current_events    = 0 } );
 144
 145         spin_lock_irqsave(&irq_lock, flags);
 146         for (irq_fd = active_fds; irq_fd != NULL; irq_fd = irq_fd->next) {
 147                 if ((irq_fd->fd == fd) && (irq_fd->type == type)) {
 148                         printk("Registering fd %d twice\n", fd);
 149                         printk("Irqs : %d, %d\n", irq_fd->irq, irq);
 150                         printk("Ids : 0x%p, 0x%p\n", irq_fd->id, dev_id);
 151                         goto out_unlock;
 152                 }
 153         }
 154
 155         if (type == IRQ_WRITE)
 156                 fd = -1;
 157
 158         tmp_pfd = NULL;
 159         n = 0;
 160
 161         while (1) {
 162                 n = os_create_pollfd(fd, events, tmp_pfd, n);
 163                 if (n == 0)
 164                         break;
 165
 166                 /* n > 0
 167                  * It means we couldn't put new pollfd to current pollfds
 168                  * and tmp_fds is NULL or too small for new pollfds array.
 169                  * Needed size is equal to n as minimum.
 170                  *
 171                  * Here we have to drop the lock in order to call
 172                  * kmalloc, which might sleep.
 173                  * If something else came in and changed the pollfds array
 174                  * so we will not be able to put new pollfd struct to pollfds
 175                  * then we free the buffer tmp_fds and try again.
 176                  */
 177                 spin_unlock_irqrestore(&irq_lock, flags);
 178                 kfree(tmp_pfd);
 179                 tmp_pfd = NULL;
 180
 181                 tmp_pfd = um_kmalloc(n);
 182                 if (tmp_pfd == NULL)
 183                         goto out_kfree;
 184
 185                 spin_lock_irqsave(&irq_lock, flags);
 186         }
 187
 188         *last_irq_ptr = new_fd;
 189         last_irq_ptr = &new_fd->next;
 190
 191         spin_unlock_irqrestore(&irq_lock, flags);
 192
 193         /* This calls activate_fd, so it has to be outside the critical
 194          * section.
 195          */
 196         maybe_sigio_broken(fd, (type == IRQ_READ));
 197
 198         return 0;
 199
 200  out_unlock:
 201         spin_unlock_irqrestore(&irq_lock, flags);
 202  out_kfree:
 203         kfree(new_fd);
 204  out:
 205         return err;
 206 }
 207
 208 static void free_irq_by_cb(int (*test)(struct irq_fd *, void *), void *arg)
 209 {
 210         unsigned long flags;
 211
 212         spin_lock_irqsave(&irq_lock, flags);
 213         os_free_irq_by_cb(test, arg, active_fds, &last_irq_ptr);
 214         spin_unlock_irqrestore(&irq_lock, flags);
 215 }
 216
 217 struct irq_and_dev {
 218         int irq;
 219         void *dev;
 220 };
 221
 222 static int same_irq_and_dev(struct irq_fd *irq, void *d)
 223 {
 224         struct irq_and_dev *data = d;
 225
 226         return ((irq->irq == data->irq) && (irq->id == data->dev));
 227 }
 228
 229 void free_irq_by_irq_and_dev(unsigned int irq, void *dev)
 230 {
 231         struct irq_and_dev data = ((struct irq_and_dev) { .irq  = irq,
 232                                                           .dev  = dev });
 233
 234         free_irq_by_cb(same_irq_and_dev, &data);
 235 }
 236
 237 static int same_fd(struct irq_fd *irq, void *fd)
 238 {
 239         return (irq->fd == *((int *)fd));
 240 }
 241
 242 void free_irq_by_fd(int fd)
 243 {
 244         free_irq_by_cb(same_fd, &fd);
 245 }
 246
 247 static struct irq_fd *find_irq_by_fd(int fd, int irqnum, int *index_out)
 248 {
 249         struct irq_fd *irq;
 250         int i = 0;
 251         int fdi;
 252
 253         for (irq = active_fds; irq != NULL; irq = irq->next) {
 254                 if ((irq->fd == fd) && (irq->irq == irqnum))
 255                         break;
 256                 i++;
 257         }
 258         if (irq == NULL) {
 259                 printk("find_irq_by_fd doesn't have descriptor %d\n", fd);
 260                 goto out;
 261         }
 262         fdi = os_get_pollfd(i);
 263         if ((fdi != -1) && (fdi != fd)) {
 264                 printk("find_irq_by_fd - mismatch between active_fds and "
 265                        "pollfds, fd %d vs %d, need %d\n", irq->fd,
 266                        fdi, fd);
 267                 irq = NULL;
 268                 goto out;
 269         }
 270         *index_out = i;
 271  out:
 272         return irq;
 273 }
 274
 275 void reactivate_fd(int fd, int irqnum)
 276 {
 277         struct irq_fd *irq;
 278         unsigned long flags;
 279         int i;
 280
 281         spin_lock_irqsave(&irq_lock, flags);
 282         irq = find_irq_by_fd(fd, irqnum, &i);
 283         if (irq == NULL) {
 284                 spin_unlock_irqrestore(&irq_lock, flags);
 285                 return;
 286         }
 287         os_set_pollfd(i, irq->fd);
 288         spin_unlock_irqrestore(&irq_lock, flags);
 289
 290         add_sigio_fd(fd);
 291 }
 292
 293 void deactivate_fd(int fd, int irqnum)
 294 {
 295         struct irq_fd *irq;
 296         unsigned long flags;
 297         int i;
 298
 299         spin_lock_irqsave(&irq_lock, flags);
 300         irq = find_irq_by_fd(fd, irqnum, &i);
 301         if(irq == NULL){
 302                 spin_unlock_irqrestore(&irq_lock, flags);
 303                 return;
 304         }
 305
 306         os_set_pollfd(i, -1);
 307         spin_unlock_irqrestore(&irq_lock, flags);
 308
 309         ignore_sigio_fd(fd);
 310 }
 311
 312 int deactivate_all_fds(void)
 313 {
 314         struct irq_fd *irq;
 315         int err;
 316
 317         for (irq = active_fds; irq != NULL; irq = irq->next) {
 318                 err = os_clear_fd_async(irq->fd);
 319                 if (err)
 320                         return err;
 321         }
 322         /* If there is a signal already queued, after unblocking ignore it */
 323         os_set_ioignore();
 324
 325         return 0;
 326 }
 327
 328 #ifdef CONFIG_MODE_TT
 329 void forward_interrupts(int pid)
 330 {
 331         struct irq_fd *irq;
 332         unsigned long flags;
 333         int err;
 334
 335         spin_lock_irqsave(&irq_lock, flags);
 336         for (irq = active_fds; irq != NULL; irq = irq->next) {
 337                 err = os_set_owner(irq->fd, pid);
 338                 if (err < 0) {
 339                         /* XXX Just remove the irq rather than
 340                          * print out an infinite stream of these
 341                          */
 342                         printk("Failed to forward %d to pid %d, err = %d\n",
 343                                irq->fd, pid, -err);
 344                 }
 345
 346                 irq->pid = pid;
 347         }
 348         spin_unlock_irqrestore(&irq_lock, flags);
 349 }
 350 #endif
 351
 352 /*
 353  * do_IRQ handles all normal device IRQ's (the special
 354  * SMP cross-CPU interrupts have their own specific
 355  * handlers).
 356  */
 357 unsigned int do_IRQ(int irq, union uml_pt_regs *regs)
 358 {
 359         struct pt_regs *old_regs = set_irq_regs((struct pt_regs *)regs);
 360         irq_enter();
 361         __do_IRQ(irq);
 362         irq_exit();
 363         set_irq_regs(old_regs);
 364         return 1;
 365 }
 366
 367 int um_request_irq(unsigned int irq, int fd, int type,
 368                    irq_handler_t handler,
 369                    unsigned long irqflags, const char * devname,
 370                    void *dev_id)
 371 {
 372         int err;
 373
 374         err = request_irq(irq, handler, irqflags, devname, dev_id);
 375         if (err)
 376                 return err;
 377
 378         if (fd != -1)
 379                 err = activate_fd(irq, fd, type, dev_id);
 380         return err;
 381 }
 382 EXPORT_SYMBOL(um_request_irq);
 383 EXPORT_SYMBOL(reactivate_fd);
 384
 385 /* hw_interrupt_type must define (startup || enable) &&
 386  * (shutdown || disable) && end */
 387 static void dummy(unsigned int irq)
 388 {
 389 }
 390
 391 /* This is used for everything else than the timer. */
 392 static struct hw_interrupt_type normal_irq_type = {
 393         .typename = "SIGIO",
 394         .release = free_irq_by_irq_and_dev,
 395         .disable = dummy,
 396         .enable = dummy,
 397         .ack = dummy,
 398         .end = dummy
 399 };
 400
 401 static struct hw_interrupt_type SIGVTALRM_irq_type = {
 402         .typename = "SIGVTALRM",
 403         .release = free_irq_by_irq_and_dev,
 404         .shutdown = dummy, /* never called */
 405         .disable = dummy,
 406         .enable = dummy,
 407         .ack = dummy,
 408         .end = dummy
 409 };
 410
 411 void __init init_IRQ(void)
 412 {
 413         int i;
 414
 415         irq_desc[TIMER_IRQ].status = IRQ_DISABLED;
 416         irq_desc[TIMER_IRQ].action = NULL;
 417         irq_desc[TIMER_IRQ].depth = 1;
 418         irq_desc[TIMER_IRQ].chip = &SIGVTALRM_irq_type;
 419         enable_irq(TIMER_IRQ);
 420         for (i = 1; i < NR_IRQS; i++) {
 421                 irq_desc[i].status = IRQ_DISABLED;
 422                 irq_desc[i].action = NULL;
 423                 irq_desc[i].depth = 1;
 424                 irq_desc[i].chip = &normal_irq_type;
 425                 enable_irq(i);
 426         }
 427 }
 428
 429 int init_aio_irq(int irq, char *name, irq_handler_t handler)
 430 {
 431         int fds[2], err;
 432
 433         err = os_pipe(fds, 1, 1);
 434         if (err) {
 435                 printk("init_aio_irq - os_pipe failed, err = %d\n", -err);
 436                 goto out;
 437         }
 438
 439         err = um_request_irq(irq, fds[0], IRQ_READ, handler,
 440                              IRQF_DISABLED | IRQF_SAMPLE_RANDOM, name,
 441                              (void *) (long) fds[0]);
 442         if (err) {
 443                 printk("init_aio_irq - : um_request_irq failed, err = %d\n",
 444                        err);
 445                 goto out_close;
 446         }
 447
 448         err = fds[1];
 449         goto out;
 450
 451  out_close:
 452         os_close_file(fds[0]);
 453         os_close_file(fds[1]);
 454  out:
 455         return err;
 456 }