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authorJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>2010-11-19 01:43:38 -0500
committerJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>2010-11-19 01:43:38 -0500
commit67cb40560940ba36de22d66f0d5d8efe235c8bb1 (patch)
tree1bc7f165e7ddaef5792fc13b4cc56b2c2b700725 /drivers/xen/evtchn.c
parentbc7fc5e33e1a093e5f9e196595843bb096471586 (diff)
parent70697d540c0598ad023a391d4c895044db9a6624 (diff)
Merge branch 'xen/dev-evtchn' into upstream/evtchn
* xen/dev-evtchn: xen/evtchn: add missing static xen/evtchn: Fix name of Xen event-channel device xen/evtchn: don't do unbind_from_irqhandler under spinlock xen/evtchn: remove spurious barrier xen/evtchn: ports start enabled xen/evtchn: dynamically allocate port_user array xen/evtchn: track enabled state for each port
Diffstat (limited to 'drivers/xen/evtchn.c')
-rw-r--r--drivers/xen/evtchn.c96
1 files changed, 74 insertions, 22 deletions
diff --git a/drivers/xen/evtchn.c b/drivers/xen/evtchn.c
index dd8e5e0f1935..ef11daf0cafe 100644
--- a/drivers/xen/evtchn.c
+++ b/drivers/xen/evtchn.c
@@ -69,20 +69,51 @@ struct per_user_data {
69 const char *name; 69 const char *name;
70}; 70};
71 71
72/* Who's bound to each port? */ 72/*
73static struct per_user_data *port_user[NR_EVENT_CHANNELS]; 73 * Who's bound to each port? This is logically an array of struct
74 * per_user_data *, but we encode the current enabled-state in bit 0.
75 */
76static unsigned long *port_user;
74static DEFINE_SPINLOCK(port_user_lock); /* protects port_user[] and ring_prod */ 77static DEFINE_SPINLOCK(port_user_lock); /* protects port_user[] and ring_prod */
75 78
76irqreturn_t evtchn_interrupt(int irq, void *data) 79static inline struct per_user_data *get_port_user(unsigned port)
80{
81 return (struct per_user_data *)(port_user[port] & ~1);
82}
83
84static inline void set_port_user(unsigned port, struct per_user_data *u)
85{
86 port_user[port] = (unsigned long)u;
87}
88
89static inline bool get_port_enabled(unsigned port)
90{
91 return port_user[port] & 1;
92}
93
94static inline void set_port_enabled(unsigned port, bool enabled)
95{
96 if (enabled)
97 port_user[port] |= 1;
98 else
99 port_user[port] &= ~1;
100}
101
102static irqreturn_t evtchn_interrupt(int irq, void *data)
77{ 103{
78 unsigned int port = (unsigned long)data; 104 unsigned int port = (unsigned long)data;
79 struct per_user_data *u; 105 struct per_user_data *u;
80 106
81 spin_lock(&port_user_lock); 107 spin_lock(&port_user_lock);
82 108
83 u = port_user[port]; 109 u = get_port_user(port);
110
111 WARN(!get_port_enabled(port),
112 "Interrupt for port %d, but apparently not enabled; per-user %p\n",
113 port, u);
84 114
85 disable_irq_nosync(irq); 115 disable_irq_nosync(irq);
116 set_port_enabled(port, false);
86 117
87 if ((u->ring_prod - u->ring_cons) < EVTCHN_RING_SIZE) { 118 if ((u->ring_prod - u->ring_cons) < EVTCHN_RING_SIZE) {
88 u->ring[EVTCHN_RING_MASK(u->ring_prod)] = port; 119 u->ring[EVTCHN_RING_MASK(u->ring_prod)] = port;
@@ -92,9 +123,8 @@ irqreturn_t evtchn_interrupt(int irq, void *data)
92 kill_fasync(&u->evtchn_async_queue, 123 kill_fasync(&u->evtchn_async_queue,
93 SIGIO, POLL_IN); 124 SIGIO, POLL_IN);
94 } 125 }
95 } else { 126 } else
96 u->ring_overflow = 1; 127 u->ring_overflow = 1;
97 }
98 128
99 spin_unlock(&port_user_lock); 129 spin_unlock(&port_user_lock);
100 130
@@ -198,9 +228,18 @@ static ssize_t evtchn_write(struct file *file, const char __user *buf,
198 goto out; 228 goto out;
199 229
200 spin_lock_irq(&port_user_lock); 230 spin_lock_irq(&port_user_lock);
201 for (i = 0; i < (count/sizeof(evtchn_port_t)); i++) 231
202 if ((kbuf[i] < NR_EVENT_CHANNELS) && (port_user[kbuf[i]] == u)) 232 for (i = 0; i < (count/sizeof(evtchn_port_t)); i++) {
203 enable_irq(irq_from_evtchn(kbuf[i])); 233 unsigned port = kbuf[i];
234
235 if (port < NR_EVENT_CHANNELS &&
236 get_port_user(port) == u &&
237 !get_port_enabled(port)) {
238 set_port_enabled(port, true);
239 enable_irq(irq_from_evtchn(port));
240 }
241 }
242
204 spin_unlock_irq(&port_user_lock); 243 spin_unlock_irq(&port_user_lock);
205 244
206 rc = count; 245 rc = count;
@@ -222,8 +261,9 @@ static int evtchn_bind_to_user(struct per_user_data *u, int port)
222 * interrupt handler yet, and our caller has already 261 * interrupt handler yet, and our caller has already
223 * serialized bind operations.) 262 * serialized bind operations.)
224 */ 263 */
225 BUG_ON(port_user[port] != NULL); 264 BUG_ON(get_port_user(port) != NULL);
226 port_user[port] = u; 265 set_port_user(port, u);
266 set_port_enabled(port, true); /* start enabled */
227 267
228 rc = bind_evtchn_to_irqhandler(port, evtchn_interrupt, IRQF_DISABLED, 268 rc = bind_evtchn_to_irqhandler(port, evtchn_interrupt, IRQF_DISABLED,
229 u->name, (void *)(unsigned long)port); 269 u->name, (void *)(unsigned long)port);
@@ -239,10 +279,7 @@ static void evtchn_unbind_from_user(struct per_user_data *u, int port)
239 279
240 unbind_from_irqhandler(irq, (void *)(unsigned long)port); 280 unbind_from_irqhandler(irq, (void *)(unsigned long)port);
241 281
242 /* make sure we unbind the irq handler before clearing the port */ 282 set_port_user(port, NULL);
243 barrier();
244
245 port_user[port] = NULL;
246} 283}
247 284
248static long evtchn_ioctl(struct file *file, 285static long evtchn_ioctl(struct file *file,
@@ -333,15 +370,17 @@ static long evtchn_ioctl(struct file *file,
333 spin_lock_irq(&port_user_lock); 370 spin_lock_irq(&port_user_lock);
334 371
335 rc = -ENOTCONN; 372 rc = -ENOTCONN;
336 if (port_user[unbind.port] != u) { 373 if (get_port_user(unbind.port) != u) {
337 spin_unlock_irq(&port_user_lock); 374 spin_unlock_irq(&port_user_lock);
338 break; 375 break;
339 } 376 }
340 377
341 evtchn_unbind_from_user(u, unbind.port); 378 disable_irq(irq_from_evtchn(unbind.port));
342 379
343 spin_unlock_irq(&port_user_lock); 380 spin_unlock_irq(&port_user_lock);
344 381
382 evtchn_unbind_from_user(u, unbind.port);
383
345 rc = 0; 384 rc = 0;
346 break; 385 break;
347 } 386 }
@@ -355,7 +394,7 @@ static long evtchn_ioctl(struct file *file,
355 394
356 if (notify.port >= NR_EVENT_CHANNELS) { 395 if (notify.port >= NR_EVENT_CHANNELS) {
357 rc = -EINVAL; 396 rc = -EINVAL;
358 } else if (port_user[notify.port] != u) { 397 } else if (get_port_user(notify.port) != u) {
359 rc = -ENOTCONN; 398 rc = -ENOTCONN;
360 } else { 399 } else {
361 notify_remote_via_evtchn(notify.port); 400 notify_remote_via_evtchn(notify.port);
@@ -444,14 +483,21 @@ static int evtchn_release(struct inode *inode, struct file *filp)
444 free_page((unsigned long)u->ring); 483 free_page((unsigned long)u->ring);
445 484
446 for (i = 0; i < NR_EVENT_CHANNELS; i++) { 485 for (i = 0; i < NR_EVENT_CHANNELS; i++) {
447 if (port_user[i] != u) 486 if (get_port_user(i) != u)
448 continue; 487 continue;
449 488
450 evtchn_unbind_from_user(port_user[i], i); 489 disable_irq(irq_from_evtchn(i));
451 } 490 }
452 491
453 spin_unlock_irq(&port_user_lock); 492 spin_unlock_irq(&port_user_lock);
454 493
494 for (i = 0; i < NR_EVENT_CHANNELS; i++) {
495 if (get_port_user(i) != u)
496 continue;
497
498 evtchn_unbind_from_user(get_port_user(i), i);
499 }
500
455 kfree(u->name); 501 kfree(u->name);
456 kfree(u); 502 kfree(u);
457 503
@@ -472,7 +518,7 @@ static const struct file_operations evtchn_fops = {
472 518
473static struct miscdevice evtchn_miscdev = { 519static struct miscdevice evtchn_miscdev = {
474 .minor = MISC_DYNAMIC_MINOR, 520 .minor = MISC_DYNAMIC_MINOR,
475 .name = "evtchn", 521 .name = "xen/evtchn",
476 .fops = &evtchn_fops, 522 .fops = &evtchn_fops,
477}; 523};
478static int __init evtchn_init(void) 524static int __init evtchn_init(void)
@@ -482,8 +528,11 @@ static int __init evtchn_init(void)
482 if (!xen_domain()) 528 if (!xen_domain())
483 return -ENODEV; 529 return -ENODEV;
484 530
531 port_user = kcalloc(NR_EVENT_CHANNELS, sizeof(*port_user), GFP_KERNEL);
532 if (port_user == NULL)
533 return -ENOMEM;
534
485 spin_lock_init(&port_user_lock); 535 spin_lock_init(&port_user_lock);
486 memset(port_user, 0, sizeof(port_user));
487 536
488 /* Create '/dev/misc/evtchn'. */ 537 /* Create '/dev/misc/evtchn'. */
489 err = misc_register(&evtchn_miscdev); 538 err = misc_register(&evtchn_miscdev);
@@ -499,6 +548,9 @@ static int __init evtchn_init(void)
499 548
500static void __exit evtchn_cleanup(void) 549static void __exit evtchn_cleanup(void)
501{ 550{
551 kfree(port_user);
552 port_user = NULL;
553
502 misc_deregister(&evtchn_miscdev); 554 misc_deregister(&evtchn_miscdev);
503} 555}
504 556