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