Loading...
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 | /*
* Copyright (C) 2000 Jeff Dike (jdike@karaya.com)
* Licensed under the GPL
*/
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <signal.h>
#include <string.h>
#include <sys/poll.h>
#include <sys/types.h>
#include <sys/time.h>
#include "user_util.h"
#include "kern_util.h"
#include "user.h"
#include "process.h"
#include "signal_user.h"
#include "sigio.h"
#include "irq_user.h"
#include "os.h"
struct irq_fd {
struct irq_fd *next;
void *id;
int fd;
int type;
int irq;
int pid;
int events;
int current_events;
int freed;
};
static struct irq_fd *active_fds = NULL;
static struct irq_fd **last_irq_ptr = &active_fds;
static struct pollfd *pollfds = NULL;
static int pollfds_num = 0;
static int pollfds_size = 0;
extern int io_count, intr_count;
void sigio_handler(int sig, union uml_pt_regs *regs)
{
struct irq_fd *irq_fd, *next;
int i, n;
if(smp_sigio_handler()) return;
while(1){
n = poll(pollfds, pollfds_num, 0);
if(n < 0){
if(errno == EINTR) continue;
printk("sigio_handler : poll returned %d, "
"errno = %d\n", n, errno);
break;
}
if(n == 0) break;
irq_fd = active_fds;
for(i = 0; i < pollfds_num; i++){
if(pollfds[i].revents != 0){
irq_fd->current_events = pollfds[i].revents;
pollfds[i].fd = -1;
}
irq_fd = irq_fd->next;
}
for(irq_fd = active_fds; irq_fd != NULL; irq_fd = next){
next = irq_fd->next;
if(irq_fd->current_events != 0){
irq_fd->current_events = 0;
do_IRQ(irq_fd->irq, regs);
/* This is here because the next irq may be
* freed in the handler. If a console goes
* away, both the read and write irqs will be
* freed. After do_IRQ, ->next will point to
* a good IRQ.
* Irqs can't be freed inside their handlers,
* so the next best thing is to have them
* marked as needing freeing, so that they
* can be freed here.
*/
next = irq_fd->next;
if(irq_fd->freed){
free_irq(irq_fd->irq, irq_fd->id);
}
}
}
}
}
int activate_ipi(int fd, int pid)
{
return(os_set_fd_async(fd, pid));
}
static void maybe_sigio_broken(int fd, int type)
{
if(isatty(fd)){
if((type == IRQ_WRITE) && !pty_output_sigio){
write_sigio_workaround();
add_sigio_fd(fd, 0);
}
else if((type == IRQ_READ) && !pty_close_sigio){
write_sigio_workaround();
add_sigio_fd(fd, 1);
}
}
}
int activate_fd(int irq, int fd, int type, void *dev_id)
{
struct pollfd *tmp_pfd;
struct irq_fd *new_fd, *irq_fd;
unsigned long flags;
int pid, events, err, n, size;
pid = os_getpid();
err = os_set_fd_async(fd, pid);
if(err < 0)
goto out;
new_fd = um_kmalloc(sizeof(*new_fd));
err = -ENOMEM;
if(new_fd == NULL)
goto out;
if(type == IRQ_READ) events = POLLIN | POLLPRI;
else events = POLLOUT;
*new_fd = ((struct irq_fd) { .next = NULL,
.id = dev_id,
.fd = fd,
.type = type,
.irq = irq,
.pid = pid,
.events = events,
.current_events = 0,
.freed = 0 } );
/* Critical section - locked by a spinlock because this stuff can
* be changed from interrupt handlers. The stuff above is done
* outside the lock because it allocates memory.
*/
/* Actually, it only looks like it can be called from interrupt
* context. The culprit is reactivate_fd, which calls
* maybe_sigio_broken, which calls write_sigio_workaround,
* which calls activate_fd. However, write_sigio_workaround should
* only be called once, at boot time. That would make it clear that
* this is called only from process context, and can be locked with
* a semaphore.
*/
flags = irq_lock();
for(irq_fd = active_fds; irq_fd != NULL; irq_fd = irq_fd->next){
if((irq_fd->fd == fd) && (irq_fd->type == type)){
printk("Registering fd %d twice\n", fd);
printk("Irqs : %d, %d\n", irq_fd->irq, irq);
printk("Ids : 0x%x, 0x%x\n", irq_fd->id, dev_id);
goto out_unlock;
}
}
n = pollfds_num;
if(n == pollfds_size){
while(1){
/* Here we have to drop the lock in order to call
* kmalloc, which might sleep. If something else
* came in and changed the pollfds array, we free
* the buffer and try again.
*/
irq_unlock(flags);
size = (pollfds_num + 1) * sizeof(pollfds[0]);
tmp_pfd = um_kmalloc(size);
flags = irq_lock();
if(tmp_pfd == NULL)
goto out_unlock;
if(n == pollfds_size)
break;
kfree(tmp_pfd);
}
if(pollfds != NULL){
memcpy(tmp_pfd, pollfds,
sizeof(pollfds[0]) * pollfds_size);
kfree(pollfds);
}
pollfds = tmp_pfd;
pollfds_size++;
}
if(type == IRQ_WRITE)
fd = -1;
pollfds[pollfds_num] = ((struct pollfd) { .fd = fd,
.events = events,
.revents = 0 });
pollfds_num++;
*last_irq_ptr = new_fd;
last_irq_ptr = &new_fd->next;
irq_unlock(flags);
/* This calls activate_fd, so it has to be outside the critical
* section.
*/
maybe_sigio_broken(fd, type);
return(0);
out_unlock:
irq_unlock(flags);
kfree(new_fd);
out:
return(err);
}
static void free_irq_by_cb(int (*test)(struct irq_fd *, void *), void *arg)
{
struct irq_fd **prev;
unsigned long flags;
int i = 0;
flags = irq_lock();
prev = &active_fds;
while(*prev != NULL){
if((*test)(*prev, arg)){
struct irq_fd *old_fd = *prev;
if((pollfds[i].fd != -1) &&
(pollfds[i].fd != (*prev)->fd)){
printk("free_irq_by_cb - mismatch between "
"active_fds and pollfds, fd %d vs %d\n",
(*prev)->fd, pollfds[i].fd);
goto out;
}
pollfds_num--;
/* This moves the *whole* array after pollfds[i] (though
* it doesn't spot as such)! */
memmove(&pollfds[i], &pollfds[i + 1],
(pollfds_num - i) * sizeof(pollfds[0]));
if(last_irq_ptr == &old_fd->next)
last_irq_ptr = prev;
*prev = (*prev)->next;
if(old_fd->type == IRQ_WRITE)
ignore_sigio_fd(old_fd->fd);
kfree(old_fd);
continue;
}
prev = &(*prev)->next;
i++;
}
out:
irq_unlock(flags);
}
struct irq_and_dev {
int irq;
void *dev;
};
static int same_irq_and_dev(struct irq_fd *irq, void *d)
{
struct irq_and_dev *data = d;
return((irq->irq == data->irq) && (irq->id == data->dev));
}
void free_irq_by_irq_and_dev(unsigned int irq, void *dev)
{
struct irq_and_dev data = ((struct irq_and_dev) { .irq = irq,
.dev = dev });
free_irq_by_cb(same_irq_and_dev, &data);
}
static int same_fd(struct irq_fd *irq, void *fd)
{
return(irq->fd == *((int *) fd));
}
void free_irq_by_fd(int fd)
{
free_irq_by_cb(same_fd, &fd);
}
static struct irq_fd *find_irq_by_fd(int fd, int irqnum, int *index_out)
{
struct irq_fd *irq;
int i = 0;
for(irq=active_fds; irq != NULL; irq = irq->next){
if((irq->fd == fd) && (irq->irq == irqnum)) break;
i++;
}
if(irq == NULL){
printk("find_irq_by_fd doesn't have descriptor %d\n", fd);
goto out;
}
if((pollfds[i].fd != -1) && (pollfds[i].fd != fd)){
printk("find_irq_by_fd - mismatch between active_fds and "
"pollfds, fd %d vs %d, need %d\n", irq->fd,
pollfds[i].fd, fd);
irq = NULL;
goto out;
}
*index_out = i;
out:
return(irq);
}
void free_irq_later(int irq, void *dev_id)
{
struct irq_fd *irq_fd;
unsigned long flags;
flags = irq_lock();
for(irq_fd = active_fds; irq_fd != NULL; irq_fd = irq_fd->next){
if((irq_fd->irq == irq) && (irq_fd->id == dev_id))
break;
}
if(irq_fd == NULL){
printk("free_irq_later found no irq, irq = %d, "
"dev_id = 0x%p\n", irq, dev_id);
goto out;
}
irq_fd->freed = 1;
out:
irq_unlock(flags);
}
void reactivate_fd(int fd, int irqnum)
{
struct irq_fd *irq;
unsigned long flags;
int i;
flags = irq_lock();
irq = find_irq_by_fd(fd, irqnum, &i);
if(irq == NULL){
irq_unlock(flags);
return;
}
pollfds[i].fd = irq->fd;
irq_unlock(flags);
/* This calls activate_fd, so it has to be outside the critical
* section.
*/
maybe_sigio_broken(fd, irq->type);
}
void deactivate_fd(int fd, int irqnum)
{
struct irq_fd *irq;
unsigned long flags;
int i;
flags = irq_lock();
irq = find_irq_by_fd(fd, irqnum, &i);
if(irq == NULL)
goto out;
pollfds[i].fd = -1;
out:
irq_unlock(flags);
}
int deactivate_all_fds(void)
{
struct irq_fd *irq;
int err;
for(irq=active_fds;irq != NULL;irq = irq->next){
err = os_clear_fd_async(irq->fd);
if(err)
return(err);
}
/* If there is a signal already queued, after unblocking ignore it */
set_handler(SIGIO, SIG_IGN, 0, -1);
return(0);
}
void forward_ipi(int fd, int pid)
{
int err;
err = os_set_owner(fd, pid);
if(err < 0)
printk("forward_ipi: set_owner failed, fd = %d, me = %d, "
"target = %d, err = %d\n", fd, os_getpid(), pid, -err);
}
void forward_interrupts(int pid)
{
struct irq_fd *irq;
unsigned long flags;
int err;
flags = irq_lock();
for(irq=active_fds;irq != NULL;irq = irq->next){
err = os_set_owner(irq->fd, pid);
if(err < 0){
/* XXX Just remove the irq rather than
* print out an infinite stream of these
*/
printk("Failed to forward %d to pid %d, err = %d\n",
irq->fd, pid, -err);
}
irq->pid = pid;
}
irq_unlock(flags);
}
void init_irq_signals(int on_sigstack)
{
__sighandler_t h;
int flags;
flags = on_sigstack ? SA_ONSTACK : 0;
if(timer_irq_inited) h = (__sighandler_t) alarm_handler;
else h = boot_timer_handler;
set_handler(SIGVTALRM, h, flags | SA_RESTART,
SIGUSR1, SIGIO, SIGWINCH, SIGALRM, -1);
set_handler(SIGIO, (__sighandler_t) sig_handler, flags | SA_RESTART,
SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1);
signal(SIGWINCH, SIG_IGN);
}
/*
* Overrides for Emacs so that we follow Linus's tabbing style.
* Emacs will notice this stuff at the end of the file and automatically
* adjust the settings for this buffer only. This must remain at the end
* of the file.
* ---------------------------------------------------------------------------
* Local variables:
* c-file-style: "linux"
* End:
*/
|