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