Drivers: hv: Make the vmbus driver unloadable
[linux-2.6.git] / drivers / hv / vmbus_drv.c
1 /*
2  * Copyright (c) 2009, Microsoft Corporation.
3  *
4  * This program is free software; you can redistribute it and/or modify it
5  * under the terms and conditions of the GNU General Public License,
6  * version 2, as published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope it will be useful, but WITHOUT
9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
11  * more details.
12  *
13  * You should have received a copy of the GNU General Public License along with
14  * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
15  * Place - Suite 330, Boston, MA 02111-1307 USA.
16  *
17  * Authors:
18  *   Haiyang Zhang <haiyangz@microsoft.com>
19  *   Hank Janssen  <hjanssen@microsoft.com>
20  *   K. Y. Srinivasan <kys@microsoft.com>
21  *
22  */
23 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
24
25 #include <linux/init.h>
26 #include <linux/module.h>
27 #include <linux/device.h>
28 #include <linux/irq.h>
29 #include <linux/interrupt.h>
30 #include <linux/sysctl.h>
31 #include <linux/slab.h>
32 #include <linux/acpi.h>
33 #include <acpi/acpi_bus.h>
34 #include <linux/completion.h>
35 #include <linux/hyperv.h>
36 #include <asm/hyperv.h>
37 #include "hyperv_vmbus.h"
38
39
40 static struct acpi_device  *hv_acpi_dev;
41
42 static struct tasklet_struct msg_dpc;
43 static struct tasklet_struct event_dpc;
44 static struct completion probe_event;
45 static int irq;
46
47 struct hv_device_info {
48         u32 chn_id;
49         u32 chn_state;
50         uuid_le chn_type;
51         uuid_le chn_instance;
52
53         u32 monitor_id;
54         u32 server_monitor_pending;
55         u32 server_monitor_latency;
56         u32 server_monitor_conn_id;
57         u32 client_monitor_pending;
58         u32 client_monitor_latency;
59         u32 client_monitor_conn_id;
60
61         struct hv_dev_port_info inbound;
62         struct hv_dev_port_info outbound;
63 };
64
65 static int vmbus_exists(void)
66 {
67         if (hv_acpi_dev == NULL)
68                 return -ENODEV;
69
70         return 0;
71 }
72
73
74 static void get_channel_info(struct hv_device *device,
75                              struct hv_device_info *info)
76 {
77         struct vmbus_channel_debug_info debug_info;
78
79         if (!device->channel)
80                 return;
81
82         vmbus_get_debug_info(device->channel, &debug_info);
83
84         info->chn_id = debug_info.relid;
85         info->chn_state = debug_info.state;
86         memcpy(&info->chn_type, &debug_info.interfacetype,
87                sizeof(uuid_le));
88         memcpy(&info->chn_instance, &debug_info.interface_instance,
89                sizeof(uuid_le));
90
91         info->monitor_id = debug_info.monitorid;
92
93         info->server_monitor_pending = debug_info.servermonitor_pending;
94         info->server_monitor_latency = debug_info.servermonitor_latency;
95         info->server_monitor_conn_id = debug_info.servermonitor_connectionid;
96
97         info->client_monitor_pending = debug_info.clientmonitor_pending;
98         info->client_monitor_latency = debug_info.clientmonitor_latency;
99         info->client_monitor_conn_id = debug_info.clientmonitor_connectionid;
100
101         info->inbound.int_mask = debug_info.inbound.current_interrupt_mask;
102         info->inbound.read_idx = debug_info.inbound.current_read_index;
103         info->inbound.write_idx = debug_info.inbound.current_write_index;
104         info->inbound.bytes_avail_toread =
105                 debug_info.inbound.bytes_avail_toread;
106         info->inbound.bytes_avail_towrite =
107                 debug_info.inbound.bytes_avail_towrite;
108
109         info->outbound.int_mask =
110                 debug_info.outbound.current_interrupt_mask;
111         info->outbound.read_idx = debug_info.outbound.current_read_index;
112         info->outbound.write_idx = debug_info.outbound.current_write_index;
113         info->outbound.bytes_avail_toread =
114                 debug_info.outbound.bytes_avail_toread;
115         info->outbound.bytes_avail_towrite =
116                 debug_info.outbound.bytes_avail_towrite;
117 }
118
119 #define VMBUS_ALIAS_LEN ((sizeof((struct hv_vmbus_device_id *)0)->guid) * 2)
120 static void print_alias_name(struct hv_device *hv_dev, char *alias_name)
121 {
122         int i;
123         for (i = 0; i < VMBUS_ALIAS_LEN; i += 2)
124                 sprintf(&alias_name[i], "%02x", hv_dev->dev_type.b[i/2]);
125 }
126
127 /*
128  * vmbus_show_device_attr - Show the device attribute in sysfs.
129  *
130  * This is invoked when user does a
131  * "cat /sys/bus/vmbus/devices/<busdevice>/<attr name>"
132  */
133 static ssize_t vmbus_show_device_attr(struct device *dev,
134                                       struct device_attribute *dev_attr,
135                                       char *buf)
136 {
137         struct hv_device *hv_dev = device_to_hv_device(dev);
138         struct hv_device_info *device_info;
139         char alias_name[VMBUS_ALIAS_LEN + 1];
140         int ret = 0;
141
142         device_info = kzalloc(sizeof(struct hv_device_info), GFP_KERNEL);
143         if (!device_info)
144                 return ret;
145
146         get_channel_info(hv_dev, device_info);
147
148         if (!strcmp(dev_attr->attr.name, "class_id")) {
149                 ret = sprintf(buf, "{%02x%02x%02x%02x-%02x%02x-%02x%02x-"
150                                "%02x%02x%02x%02x%02x%02x%02x%02x}\n",
151                                device_info->chn_type.b[3],
152                                device_info->chn_type.b[2],
153                                device_info->chn_type.b[1],
154                                device_info->chn_type.b[0],
155                                device_info->chn_type.b[5],
156                                device_info->chn_type.b[4],
157                                device_info->chn_type.b[7],
158                                device_info->chn_type.b[6],
159                                device_info->chn_type.b[8],
160                                device_info->chn_type.b[9],
161                                device_info->chn_type.b[10],
162                                device_info->chn_type.b[11],
163                                device_info->chn_type.b[12],
164                                device_info->chn_type.b[13],
165                                device_info->chn_type.b[14],
166                                device_info->chn_type.b[15]);
167         } else if (!strcmp(dev_attr->attr.name, "device_id")) {
168                 ret = sprintf(buf, "{%02x%02x%02x%02x-%02x%02x-%02x%02x-"
169                                "%02x%02x%02x%02x%02x%02x%02x%02x}\n",
170                                device_info->chn_instance.b[3],
171                                device_info->chn_instance.b[2],
172                                device_info->chn_instance.b[1],
173                                device_info->chn_instance.b[0],
174                                device_info->chn_instance.b[5],
175                                device_info->chn_instance.b[4],
176                                device_info->chn_instance.b[7],
177                                device_info->chn_instance.b[6],
178                                device_info->chn_instance.b[8],
179                                device_info->chn_instance.b[9],
180                                device_info->chn_instance.b[10],
181                                device_info->chn_instance.b[11],
182                                device_info->chn_instance.b[12],
183                                device_info->chn_instance.b[13],
184                                device_info->chn_instance.b[14],
185                                device_info->chn_instance.b[15]);
186         } else if (!strcmp(dev_attr->attr.name, "modalias")) {
187                 print_alias_name(hv_dev, alias_name);
188                 ret = sprintf(buf, "vmbus:%s\n", alias_name);
189         } else if (!strcmp(dev_attr->attr.name, "state")) {
190                 ret = sprintf(buf, "%d\n", device_info->chn_state);
191         } else if (!strcmp(dev_attr->attr.name, "id")) {
192                 ret = sprintf(buf, "%d\n", device_info->chn_id);
193         } else if (!strcmp(dev_attr->attr.name, "out_intr_mask")) {
194                 ret = sprintf(buf, "%d\n", device_info->outbound.int_mask);
195         } else if (!strcmp(dev_attr->attr.name, "out_read_index")) {
196                 ret = sprintf(buf, "%d\n", device_info->outbound.read_idx);
197         } else if (!strcmp(dev_attr->attr.name, "out_write_index")) {
198                 ret = sprintf(buf, "%d\n", device_info->outbound.write_idx);
199         } else if (!strcmp(dev_attr->attr.name, "out_read_bytes_avail")) {
200                 ret = sprintf(buf, "%d\n",
201                                device_info->outbound.bytes_avail_toread);
202         } else if (!strcmp(dev_attr->attr.name, "out_write_bytes_avail")) {
203                 ret = sprintf(buf, "%d\n",
204                                device_info->outbound.bytes_avail_towrite);
205         } else if (!strcmp(dev_attr->attr.name, "in_intr_mask")) {
206                 ret = sprintf(buf, "%d\n", device_info->inbound.int_mask);
207         } else if (!strcmp(dev_attr->attr.name, "in_read_index")) {
208                 ret = sprintf(buf, "%d\n", device_info->inbound.read_idx);
209         } else if (!strcmp(dev_attr->attr.name, "in_write_index")) {
210                 ret = sprintf(buf, "%d\n", device_info->inbound.write_idx);
211         } else if (!strcmp(dev_attr->attr.name, "in_read_bytes_avail")) {
212                 ret = sprintf(buf, "%d\n",
213                                device_info->inbound.bytes_avail_toread);
214         } else if (!strcmp(dev_attr->attr.name, "in_write_bytes_avail")) {
215                 ret = sprintf(buf, "%d\n",
216                                device_info->inbound.bytes_avail_towrite);
217         } else if (!strcmp(dev_attr->attr.name, "monitor_id")) {
218                 ret = sprintf(buf, "%d\n", device_info->monitor_id);
219         } else if (!strcmp(dev_attr->attr.name, "server_monitor_pending")) {
220                 ret = sprintf(buf, "%d\n", device_info->server_monitor_pending);
221         } else if (!strcmp(dev_attr->attr.name, "server_monitor_latency")) {
222                 ret = sprintf(buf, "%d\n", device_info->server_monitor_latency);
223         } else if (!strcmp(dev_attr->attr.name, "server_monitor_conn_id")) {
224                 ret = sprintf(buf, "%d\n",
225                                device_info->server_monitor_conn_id);
226         } else if (!strcmp(dev_attr->attr.name, "client_monitor_pending")) {
227                 ret = sprintf(buf, "%d\n", device_info->client_monitor_pending);
228         } else if (!strcmp(dev_attr->attr.name, "client_monitor_latency")) {
229                 ret = sprintf(buf, "%d\n", device_info->client_monitor_latency);
230         } else if (!strcmp(dev_attr->attr.name, "client_monitor_conn_id")) {
231                 ret = sprintf(buf, "%d\n",
232                                device_info->client_monitor_conn_id);
233         }
234
235         kfree(device_info);
236         return ret;
237 }
238
239 /* Set up per device attributes in /sys/bus/vmbus/devices/<bus device> */
240 static struct device_attribute vmbus_device_attrs[] = {
241         __ATTR(id, S_IRUGO, vmbus_show_device_attr, NULL),
242         __ATTR(state, S_IRUGO, vmbus_show_device_attr, NULL),
243         __ATTR(class_id, S_IRUGO, vmbus_show_device_attr, NULL),
244         __ATTR(device_id, S_IRUGO, vmbus_show_device_attr, NULL),
245         __ATTR(monitor_id, S_IRUGO, vmbus_show_device_attr, NULL),
246         __ATTR(modalias, S_IRUGO, vmbus_show_device_attr, NULL),
247
248         __ATTR(server_monitor_pending, S_IRUGO, vmbus_show_device_attr, NULL),
249         __ATTR(server_monitor_latency, S_IRUGO, vmbus_show_device_attr, NULL),
250         __ATTR(server_monitor_conn_id, S_IRUGO, vmbus_show_device_attr, NULL),
251
252         __ATTR(client_monitor_pending, S_IRUGO, vmbus_show_device_attr, NULL),
253         __ATTR(client_monitor_latency, S_IRUGO, vmbus_show_device_attr, NULL),
254         __ATTR(client_monitor_conn_id, S_IRUGO, vmbus_show_device_attr, NULL),
255
256         __ATTR(out_intr_mask, S_IRUGO, vmbus_show_device_attr, NULL),
257         __ATTR(out_read_index, S_IRUGO, vmbus_show_device_attr, NULL),
258         __ATTR(out_write_index, S_IRUGO, vmbus_show_device_attr, NULL),
259         __ATTR(out_read_bytes_avail, S_IRUGO, vmbus_show_device_attr, NULL),
260         __ATTR(out_write_bytes_avail, S_IRUGO, vmbus_show_device_attr, NULL),
261
262         __ATTR(in_intr_mask, S_IRUGO, vmbus_show_device_attr, NULL),
263         __ATTR(in_read_index, S_IRUGO, vmbus_show_device_attr, NULL),
264         __ATTR(in_write_index, S_IRUGO, vmbus_show_device_attr, NULL),
265         __ATTR(in_read_bytes_avail, S_IRUGO, vmbus_show_device_attr, NULL),
266         __ATTR(in_write_bytes_avail, S_IRUGO, vmbus_show_device_attr, NULL),
267         __ATTR_NULL
268 };
269
270
271 /*
272  * vmbus_uevent - add uevent for our device
273  *
274  * This routine is invoked when a device is added or removed on the vmbus to
275  * generate a uevent to udev in the userspace. The udev will then look at its
276  * rule and the uevent generated here to load the appropriate driver
277  *
278  * The alias string will be of the form vmbus:guid where guid is the string
279  * representation of the device guid (each byte of the guid will be
280  * represented with two hex characters.
281  */
282 static int vmbus_uevent(struct device *device, struct kobj_uevent_env *env)
283 {
284         struct hv_device *dev = device_to_hv_device(device);
285         int ret;
286         char alias_name[VMBUS_ALIAS_LEN + 1];
287
288         print_alias_name(dev, alias_name);
289         ret = add_uevent_var(env, "MODALIAS=vmbus:%s", alias_name);
290         return ret;
291 }
292
293 static uuid_le null_guid;
294
295 static inline bool is_null_guid(const __u8 *guid)
296 {
297         if (memcmp(guid, &null_guid, sizeof(uuid_le)))
298                 return false;
299         return true;
300 }
301
302 /*
303  * Return a matching hv_vmbus_device_id pointer.
304  * If there is no match, return NULL.
305  */
306 static const struct hv_vmbus_device_id *hv_vmbus_get_id(
307                                         const struct hv_vmbus_device_id *id,
308                                         __u8 *guid)
309 {
310         for (; !is_null_guid(id->guid); id++)
311                 if (!memcmp(&id->guid, guid, sizeof(uuid_le)))
312                         return id;
313
314         return NULL;
315 }
316
317
318
319 /*
320  * vmbus_match - Attempt to match the specified device to the specified driver
321  */
322 static int vmbus_match(struct device *device, struct device_driver *driver)
323 {
324         struct hv_driver *drv = drv_to_hv_drv(driver);
325         struct hv_device *hv_dev = device_to_hv_device(device);
326
327         if (hv_vmbus_get_id(drv->id_table, hv_dev->dev_type.b))
328                 return 1;
329
330         return 0;
331 }
332
333 /*
334  * vmbus_probe - Add the new vmbus's child device
335  */
336 static int vmbus_probe(struct device *child_device)
337 {
338         int ret = 0;
339         struct hv_driver *drv =
340                         drv_to_hv_drv(child_device->driver);
341         struct hv_device *dev = device_to_hv_device(child_device);
342         const struct hv_vmbus_device_id *dev_id;
343
344         dev_id = hv_vmbus_get_id(drv->id_table, dev->dev_type.b);
345         if (drv->probe) {
346                 ret = drv->probe(dev, dev_id);
347                 if (ret != 0)
348                         pr_err("probe failed for device %s (%d)\n",
349                                dev_name(child_device), ret);
350
351         } else {
352                 pr_err("probe not set for driver %s\n",
353                        dev_name(child_device));
354                 ret = -ENODEV;
355         }
356         return ret;
357 }
358
359 /*
360  * vmbus_remove - Remove a vmbus device
361  */
362 static int vmbus_remove(struct device *child_device)
363 {
364         struct hv_driver *drv = drv_to_hv_drv(child_device->driver);
365         struct hv_device *dev = device_to_hv_device(child_device);
366
367         if (drv->remove)
368                 drv->remove(dev);
369         else
370                 pr_err("remove not set for driver %s\n",
371                         dev_name(child_device));
372
373         return 0;
374 }
375
376
377 /*
378  * vmbus_shutdown - Shutdown a vmbus device
379  */
380 static void vmbus_shutdown(struct device *child_device)
381 {
382         struct hv_driver *drv;
383         struct hv_device *dev = device_to_hv_device(child_device);
384
385
386         /* The device may not be attached yet */
387         if (!child_device->driver)
388                 return;
389
390         drv = drv_to_hv_drv(child_device->driver);
391
392         if (drv->shutdown)
393                 drv->shutdown(dev);
394
395         return;
396 }
397
398
399 /*
400  * vmbus_device_release - Final callback release of the vmbus child device
401  */
402 static void vmbus_device_release(struct device *device)
403 {
404         struct hv_device *hv_dev = device_to_hv_device(device);
405
406         kfree(hv_dev);
407
408 }
409
410 /* The one and only one */
411 static struct bus_type  hv_bus = {
412         .name =         "vmbus",
413         .match =                vmbus_match,
414         .shutdown =             vmbus_shutdown,
415         .remove =               vmbus_remove,
416         .probe =                vmbus_probe,
417         .uevent =               vmbus_uevent,
418         .dev_attrs =    vmbus_device_attrs,
419 };
420
421 static const char *driver_name = "hyperv";
422
423
424 struct onmessage_work_context {
425         struct work_struct work;
426         struct hv_message msg;
427 };
428
429 static void vmbus_onmessage_work(struct work_struct *work)
430 {
431         struct onmessage_work_context *ctx;
432
433         ctx = container_of(work, struct onmessage_work_context,
434                            work);
435         vmbus_onmessage(&ctx->msg);
436         kfree(ctx);
437 }
438
439 static void vmbus_on_msg_dpc(unsigned long data)
440 {
441         int cpu = smp_processor_id();
442         void *page_addr = hv_context.synic_message_page[cpu];
443         struct hv_message *msg = (struct hv_message *)page_addr +
444                                   VMBUS_MESSAGE_SINT;
445         struct onmessage_work_context *ctx;
446
447         while (1) {
448                 if (msg->header.message_type == HVMSG_NONE) {
449                         /* no msg */
450                         break;
451                 } else {
452                         ctx = kmalloc(sizeof(*ctx), GFP_ATOMIC);
453                         if (ctx == NULL)
454                                 continue;
455                         INIT_WORK(&ctx->work, vmbus_onmessage_work);
456                         memcpy(&ctx->msg, msg, sizeof(*msg));
457                         queue_work(vmbus_connection.work_queue, &ctx->work);
458                 }
459
460                 msg->header.message_type = HVMSG_NONE;
461
462                 /*
463                  * Make sure the write to MessageType (ie set to
464                  * HVMSG_NONE) happens before we read the
465                  * MessagePending and EOMing. Otherwise, the EOMing
466                  * will not deliver any more messages since there is
467                  * no empty slot
468                  */
469                 smp_mb();
470
471                 if (msg->header.message_flags.msg_pending) {
472                         /*
473                          * This will cause message queue rescan to
474                          * possibly deliver another msg from the
475                          * hypervisor
476                          */
477                         wrmsrl(HV_X64_MSR_EOM, 0);
478                 }
479         }
480 }
481
482 static irqreturn_t vmbus_isr(int irq, void *dev_id)
483 {
484         int cpu = smp_processor_id();
485         void *page_addr;
486         struct hv_message *msg;
487         union hv_synic_event_flags *event;
488         bool handled = false;
489
490         /*
491          * Check for events before checking for messages. This is the order
492          * in which events and messages are checked in Windows guests on
493          * Hyper-V, and the Windows team suggested we do the same.
494          */
495
496         page_addr = hv_context.synic_event_page[cpu];
497         event = (union hv_synic_event_flags *)page_addr + VMBUS_MESSAGE_SINT;
498
499         /* Since we are a child, we only need to check bit 0 */
500         if (sync_test_and_clear_bit(0, (unsigned long *) &event->flags32[0])) {
501                 handled = true;
502                 tasklet_schedule(&event_dpc);
503         }
504
505         page_addr = hv_context.synic_message_page[cpu];
506         msg = (struct hv_message *)page_addr + VMBUS_MESSAGE_SINT;
507
508         /* Check if there are actual msgs to be processed */
509         if (msg->header.message_type != HVMSG_NONE) {
510                 handled = true;
511                 tasklet_schedule(&msg_dpc);
512         }
513
514         if (handled)
515                 return IRQ_HANDLED;
516         else
517                 return IRQ_NONE;
518 }
519
520 /*
521  * vmbus_bus_init -Main vmbus driver initialization routine.
522  *
523  * Here, we
524  *      - initialize the vmbus driver context
525  *      - invoke the vmbus hv main init routine
526  *      - get the irq resource
527  *      - retrieve the channel offers
528  */
529 static int vmbus_bus_init(int irq)
530 {
531         int ret;
532         unsigned int vector;
533
534         /* Hypervisor initialization...setup hypercall page..etc */
535         ret = hv_init();
536         if (ret != 0) {
537                 pr_err("Unable to initialize the hypervisor - 0x%x\n", ret);
538                 return ret;
539         }
540
541         tasklet_init(&msg_dpc, vmbus_on_msg_dpc, 0);
542         tasklet_init(&event_dpc, vmbus_on_event, 0);
543
544         ret = bus_register(&hv_bus);
545         if (ret)
546                 goto err_cleanup;
547
548         ret = request_irq(irq, vmbus_isr, IRQF_SAMPLE_RANDOM,
549                         driver_name, hv_acpi_dev);
550
551         if (ret != 0) {
552                 pr_err("Unable to request IRQ %d\n",
553                            irq);
554                 goto err_unregister;
555         }
556
557         vector = IRQ0_VECTOR + irq;
558
559         /*
560          * Notify the hypervisor of our irq and
561          * connect to the host.
562          */
563         on_each_cpu(hv_synic_init, (void *)&vector, 1);
564         ret = vmbus_connect();
565         if (ret)
566                 goto err_irq;
567
568         vmbus_request_offers();
569
570         return 0;
571
572 err_irq:
573         free_irq(irq, hv_acpi_dev);
574
575 err_unregister:
576         bus_unregister(&hv_bus);
577
578 err_cleanup:
579         hv_cleanup();
580
581         return ret;
582 }
583
584 /**
585  * __vmbus_child_driver_register - Register a vmbus's driver
586  * @drv: Pointer to driver structure you want to register
587  * @owner: owner module of the drv
588  * @mod_name: module name string
589  *
590  * Registers the given driver with Linux through the 'driver_register()' call
591  * and sets up the hyper-v vmbus handling for this driver.
592  * It will return the state of the 'driver_register()' call.
593  *
594  */
595 int __vmbus_driver_register(struct hv_driver *hv_driver, struct module *owner, const char *mod_name)
596 {
597         int ret;
598
599         pr_info("registering driver %s\n", hv_driver->name);
600
601         ret = vmbus_exists();
602         if (ret < 0)
603                 return ret;
604
605         hv_driver->driver.name = hv_driver->name;
606         hv_driver->driver.owner = owner;
607         hv_driver->driver.mod_name = mod_name;
608         hv_driver->driver.bus = &hv_bus;
609
610         ret = driver_register(&hv_driver->driver);
611
612         vmbus_request_offers();
613
614         return ret;
615 }
616 EXPORT_SYMBOL_GPL(__vmbus_driver_register);
617
618 /**
619  * vmbus_driver_unregister() - Unregister a vmbus's driver
620  * @drv: Pointer to driver structure you want to un-register
621  *
622  * Un-register the given driver that was previous registered with a call to
623  * vmbus_driver_register()
624  */
625 void vmbus_driver_unregister(struct hv_driver *hv_driver)
626 {
627         pr_info("unregistering driver %s\n", hv_driver->name);
628
629         if (!vmbus_exists())
630                 return;
631
632         driver_unregister(&hv_driver->driver);
633
634 }
635 EXPORT_SYMBOL_GPL(vmbus_driver_unregister);
636
637 /*
638  * vmbus_device_create - Creates and registers a new child device
639  * on the vmbus.
640  */
641 struct hv_device *vmbus_device_create(uuid_le *type,
642                                             uuid_le *instance,
643                                             struct vmbus_channel *channel)
644 {
645         struct hv_device *child_device_obj;
646
647         child_device_obj = kzalloc(sizeof(struct hv_device), GFP_KERNEL);
648         if (!child_device_obj) {
649                 pr_err("Unable to allocate device object for child device\n");
650                 return NULL;
651         }
652
653         child_device_obj->channel = channel;
654         memcpy(&child_device_obj->dev_type, type, sizeof(uuid_le));
655         memcpy(&child_device_obj->dev_instance, instance,
656                sizeof(uuid_le));
657
658
659         return child_device_obj;
660 }
661
662 /*
663  * vmbus_device_register - Register the child device
664  */
665 int vmbus_device_register(struct hv_device *child_device_obj)
666 {
667         int ret = 0;
668
669         static atomic_t device_num = ATOMIC_INIT(0);
670
671         dev_set_name(&child_device_obj->device, "vmbus_0_%d",
672                      atomic_inc_return(&device_num));
673
674         child_device_obj->device.bus = &hv_bus;
675         child_device_obj->device.parent = &hv_acpi_dev->dev;
676         child_device_obj->device.release = vmbus_device_release;
677
678         /*
679          * Register with the LDM. This will kick off the driver/device
680          * binding...which will eventually call vmbus_match() and vmbus_probe()
681          */
682         ret = device_register(&child_device_obj->device);
683
684         if (ret)
685                 pr_err("Unable to register child device\n");
686         else
687                 pr_info("child device %s registered\n",
688                         dev_name(&child_device_obj->device));
689
690         return ret;
691 }
692
693 /*
694  * vmbus_device_unregister - Remove the specified child device
695  * from the vmbus.
696  */
697 void vmbus_device_unregister(struct hv_device *device_obj)
698 {
699         /*
700          * Kick off the process of unregistering the device.
701          * This will call vmbus_remove() and eventually vmbus_device_release()
702          */
703         device_unregister(&device_obj->device);
704
705         pr_info("child device %s unregistered\n",
706                 dev_name(&device_obj->device));
707 }
708
709
710 /*
711  * VMBUS is an acpi enumerated device. Get the the IRQ information
712  * from DSDT.
713  */
714
715 static acpi_status vmbus_walk_resources(struct acpi_resource *res, void *irq)
716 {
717
718         if (res->type == ACPI_RESOURCE_TYPE_IRQ) {
719                 struct acpi_resource_irq *irqp;
720                 irqp = &res->data.irq;
721
722                 *((unsigned int *)irq) = irqp->interrupts[0];
723         }
724
725         return AE_OK;
726 }
727
728 static int vmbus_acpi_add(struct acpi_device *device)
729 {
730         acpi_status result;
731
732         hv_acpi_dev = device;
733
734         result = acpi_walk_resources(device->handle, METHOD_NAME__CRS,
735                                         vmbus_walk_resources, &irq);
736
737         if (ACPI_FAILURE(result)) {
738                 complete(&probe_event);
739                 return -ENODEV;
740         }
741         complete(&probe_event);
742         return 0;
743 }
744
745 static const struct acpi_device_id vmbus_acpi_device_ids[] = {
746         {"VMBUS", 0},
747         {"VMBus", 0},
748         {"", 0},
749 };
750 MODULE_DEVICE_TABLE(acpi, vmbus_acpi_device_ids);
751
752 static struct acpi_driver vmbus_acpi_driver = {
753         .name = "vmbus",
754         .ids = vmbus_acpi_device_ids,
755         .ops = {
756                 .add = vmbus_acpi_add,
757         },
758 };
759
760 static int __init hv_acpi_init(void)
761 {
762         int ret, t;
763
764         init_completion(&probe_event);
765
766         /*
767          * Get irq resources first.
768          */
769
770         ret = acpi_bus_register_driver(&vmbus_acpi_driver);
771
772         if (ret)
773                 return ret;
774
775         t = wait_for_completion_timeout(&probe_event, 5*HZ);
776         if (t == 0) {
777                 ret = -ETIMEDOUT;
778                 goto cleanup;
779         }
780
781         if (irq <= 0) {
782                 ret = -ENODEV;
783                 goto cleanup;
784         }
785
786         ret = vmbus_bus_init(irq);
787         if (ret)
788                 goto cleanup;
789
790         return 0;
791
792 cleanup:
793         acpi_bus_unregister_driver(&vmbus_acpi_driver);
794         hv_acpi_dev = NULL;
795         return ret;
796 }
797
798 static void __exit vmbus_exit(void)
799 {
800
801         free_irq(irq, hv_acpi_dev);
802         vmbus_free_channels();
803         bus_unregister(&hv_bus);
804         hv_cleanup();
805         acpi_bus_unregister_driver(&vmbus_acpi_driver);
806 }
807
808
809 MODULE_LICENSE("GPL");
810 MODULE_VERSION(HV_DRV_VERSION);
811
812 subsys_initcall(hv_acpi_init);
813 module_exit(vmbus_exit);