2 * Copyright (c) 2009, Microsoft Corporation.
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.
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
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.
18 * Haiyang Zhang <haiyangz@microsoft.com>
19 * Hank Janssen <hjanssen@microsoft.com>
20 * K. Y. Srinivasan <kys@microsoft.com>
23 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
25 #include <linux/init.h>
26 #include <linux/module.h>
27 #include <linux/device.h>
28 #include <linux/interrupt.h>
29 #include <linux/sysctl.h>
30 #include <linux/slab.h>
31 #include <linux/acpi.h>
32 #include <linux/completion.h>
33 #include <linux/hyperv.h>
34 #include <linux/kernel_stat.h>
35 #include <linux/clockchips.h>
36 #include <linux/cpu.h>
37 #include <linux/sched/task_stack.h>
39 #include <asm/mshyperv.h>
40 #include <linux/notifier.h>
41 #include <linux/ptrace.h>
42 #include <linux/screen_info.h>
43 #include <linux/kdebug.h>
44 #include <linux/efi.h>
45 #include <linux/random.h>
46 #include "hyperv_vmbus.h"
49 struct list_head node;
50 struct hv_vmbus_device_id id;
53 static struct acpi_device *hv_acpi_dev;
55 static struct completion probe_event;
57 static int hyperv_cpuhp_online;
59 static void *hv_panic_page;
61 static int hyperv_panic_event(struct notifier_block *nb, unsigned long val,
66 regs = current_pt_regs();
68 hyperv_report_panic(regs, val);
72 static int hyperv_die_event(struct notifier_block *nb, unsigned long val,
75 struct die_args *die = (struct die_args *)args;
76 struct pt_regs *regs = die->regs;
78 hyperv_report_panic(regs, val);
82 static struct notifier_block hyperv_die_block = {
83 .notifier_call = hyperv_die_event,
85 static struct notifier_block hyperv_panic_block = {
86 .notifier_call = hyperv_panic_event,
89 static const char *fb_mmio_name = "fb_range";
90 static struct resource *fb_mmio;
91 static struct resource *hyperv_mmio;
92 static DEFINE_SEMAPHORE(hyperv_mmio_lock);
94 static int vmbus_exists(void)
96 if (hv_acpi_dev == NULL)
102 #define VMBUS_ALIAS_LEN ((sizeof((struct hv_vmbus_device_id *)0)->guid) * 2)
103 static void print_alias_name(struct hv_device *hv_dev, char *alias_name)
106 for (i = 0; i < VMBUS_ALIAS_LEN; i += 2)
107 sprintf(&alias_name[i], "%02x", hv_dev->dev_type.b[i/2]);
110 static u8 channel_monitor_group(const struct vmbus_channel *channel)
112 return (u8)channel->offermsg.monitorid / 32;
115 static u8 channel_monitor_offset(const struct vmbus_channel *channel)
117 return (u8)channel->offermsg.monitorid % 32;
120 static u32 channel_pending(const struct vmbus_channel *channel,
121 const struct hv_monitor_page *monitor_page)
123 u8 monitor_group = channel_monitor_group(channel);
125 return monitor_page->trigger_group[monitor_group].pending;
128 static u32 channel_latency(const struct vmbus_channel *channel,
129 const struct hv_monitor_page *monitor_page)
131 u8 monitor_group = channel_monitor_group(channel);
132 u8 monitor_offset = channel_monitor_offset(channel);
134 return monitor_page->latency[monitor_group][monitor_offset];
137 static u32 channel_conn_id(struct vmbus_channel *channel,
138 struct hv_monitor_page *monitor_page)
140 u8 monitor_group = channel_monitor_group(channel);
141 u8 monitor_offset = channel_monitor_offset(channel);
142 return monitor_page->parameter[monitor_group][monitor_offset].connectionid.u.id;
145 static ssize_t id_show(struct device *dev, struct device_attribute *dev_attr,
148 struct hv_device *hv_dev = device_to_hv_device(dev);
150 if (!hv_dev->channel)
152 return sprintf(buf, "%d\n", hv_dev->channel->offermsg.child_relid);
154 static DEVICE_ATTR_RO(id);
156 static ssize_t state_show(struct device *dev, struct device_attribute *dev_attr,
159 struct hv_device *hv_dev = device_to_hv_device(dev);
161 if (!hv_dev->channel)
163 return sprintf(buf, "%d\n", hv_dev->channel->state);
165 static DEVICE_ATTR_RO(state);
167 static ssize_t monitor_id_show(struct device *dev,
168 struct device_attribute *dev_attr, char *buf)
170 struct hv_device *hv_dev = device_to_hv_device(dev);
172 if (!hv_dev->channel)
174 return sprintf(buf, "%d\n", hv_dev->channel->offermsg.monitorid);
176 static DEVICE_ATTR_RO(monitor_id);
178 static ssize_t class_id_show(struct device *dev,
179 struct device_attribute *dev_attr, char *buf)
181 struct hv_device *hv_dev = device_to_hv_device(dev);
183 if (!hv_dev->channel)
185 return sprintf(buf, "{%pUl}\n",
186 hv_dev->channel->offermsg.offer.if_type.b);
188 static DEVICE_ATTR_RO(class_id);
190 static ssize_t device_id_show(struct device *dev,
191 struct device_attribute *dev_attr, char *buf)
193 struct hv_device *hv_dev = device_to_hv_device(dev);
195 if (!hv_dev->channel)
197 return sprintf(buf, "{%pUl}\n",
198 hv_dev->channel->offermsg.offer.if_instance.b);
200 static DEVICE_ATTR_RO(device_id);
202 static ssize_t modalias_show(struct device *dev,
203 struct device_attribute *dev_attr, char *buf)
205 struct hv_device *hv_dev = device_to_hv_device(dev);
206 char alias_name[VMBUS_ALIAS_LEN + 1];
208 print_alias_name(hv_dev, alias_name);
209 return sprintf(buf, "vmbus:%s\n", alias_name);
211 static DEVICE_ATTR_RO(modalias);
214 static ssize_t numa_node_show(struct device *dev,
215 struct device_attribute *attr, char *buf)
217 struct hv_device *hv_dev = device_to_hv_device(dev);
219 if (!hv_dev->channel)
222 return sprintf(buf, "%d\n", hv_dev->channel->numa_node);
224 static DEVICE_ATTR_RO(numa_node);
227 static ssize_t server_monitor_pending_show(struct device *dev,
228 struct device_attribute *dev_attr,
231 struct hv_device *hv_dev = device_to_hv_device(dev);
233 if (!hv_dev->channel)
235 return sprintf(buf, "%d\n",
236 channel_pending(hv_dev->channel,
237 vmbus_connection.monitor_pages[0]));
239 static DEVICE_ATTR_RO(server_monitor_pending);
241 static ssize_t client_monitor_pending_show(struct device *dev,
242 struct device_attribute *dev_attr,
245 struct hv_device *hv_dev = device_to_hv_device(dev);
247 if (!hv_dev->channel)
249 return sprintf(buf, "%d\n",
250 channel_pending(hv_dev->channel,
251 vmbus_connection.monitor_pages[1]));
253 static DEVICE_ATTR_RO(client_monitor_pending);
255 static ssize_t server_monitor_latency_show(struct device *dev,
256 struct device_attribute *dev_attr,
259 struct hv_device *hv_dev = device_to_hv_device(dev);
261 if (!hv_dev->channel)
263 return sprintf(buf, "%d\n",
264 channel_latency(hv_dev->channel,
265 vmbus_connection.monitor_pages[0]));
267 static DEVICE_ATTR_RO(server_monitor_latency);
269 static ssize_t client_monitor_latency_show(struct device *dev,
270 struct device_attribute *dev_attr,
273 struct hv_device *hv_dev = device_to_hv_device(dev);
275 if (!hv_dev->channel)
277 return sprintf(buf, "%d\n",
278 channel_latency(hv_dev->channel,
279 vmbus_connection.monitor_pages[1]));
281 static DEVICE_ATTR_RO(client_monitor_latency);
283 static ssize_t server_monitor_conn_id_show(struct device *dev,
284 struct device_attribute *dev_attr,
287 struct hv_device *hv_dev = device_to_hv_device(dev);
289 if (!hv_dev->channel)
291 return sprintf(buf, "%d\n",
292 channel_conn_id(hv_dev->channel,
293 vmbus_connection.monitor_pages[0]));
295 static DEVICE_ATTR_RO(server_monitor_conn_id);
297 static ssize_t client_monitor_conn_id_show(struct device *dev,
298 struct device_attribute *dev_attr,
301 struct hv_device *hv_dev = device_to_hv_device(dev);
303 if (!hv_dev->channel)
305 return sprintf(buf, "%d\n",
306 channel_conn_id(hv_dev->channel,
307 vmbus_connection.monitor_pages[1]));
309 static DEVICE_ATTR_RO(client_monitor_conn_id);
311 static ssize_t out_intr_mask_show(struct device *dev,
312 struct device_attribute *dev_attr, char *buf)
314 struct hv_device *hv_dev = device_to_hv_device(dev);
315 struct hv_ring_buffer_debug_info outbound;
318 if (!hv_dev->channel)
321 ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound,
326 return sprintf(buf, "%d\n", outbound.current_interrupt_mask);
328 static DEVICE_ATTR_RO(out_intr_mask);
330 static ssize_t out_read_index_show(struct device *dev,
331 struct device_attribute *dev_attr, char *buf)
333 struct hv_device *hv_dev = device_to_hv_device(dev);
334 struct hv_ring_buffer_debug_info outbound;
337 if (!hv_dev->channel)
340 ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound,
344 return sprintf(buf, "%d\n", outbound.current_read_index);
346 static DEVICE_ATTR_RO(out_read_index);
348 static ssize_t out_write_index_show(struct device *dev,
349 struct device_attribute *dev_attr,
352 struct hv_device *hv_dev = device_to_hv_device(dev);
353 struct hv_ring_buffer_debug_info outbound;
356 if (!hv_dev->channel)
359 ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound,
363 return sprintf(buf, "%d\n", outbound.current_write_index);
365 static DEVICE_ATTR_RO(out_write_index);
367 static ssize_t out_read_bytes_avail_show(struct device *dev,
368 struct device_attribute *dev_attr,
371 struct hv_device *hv_dev = device_to_hv_device(dev);
372 struct hv_ring_buffer_debug_info outbound;
375 if (!hv_dev->channel)
378 ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound,
382 return sprintf(buf, "%d\n", outbound.bytes_avail_toread);
384 static DEVICE_ATTR_RO(out_read_bytes_avail);
386 static ssize_t out_write_bytes_avail_show(struct device *dev,
387 struct device_attribute *dev_attr,
390 struct hv_device *hv_dev = device_to_hv_device(dev);
391 struct hv_ring_buffer_debug_info outbound;
394 if (!hv_dev->channel)
397 ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound,
401 return sprintf(buf, "%d\n", outbound.bytes_avail_towrite);
403 static DEVICE_ATTR_RO(out_write_bytes_avail);
405 static ssize_t in_intr_mask_show(struct device *dev,
406 struct device_attribute *dev_attr, char *buf)
408 struct hv_device *hv_dev = device_to_hv_device(dev);
409 struct hv_ring_buffer_debug_info inbound;
412 if (!hv_dev->channel)
415 ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
419 return sprintf(buf, "%d\n", inbound.current_interrupt_mask);
421 static DEVICE_ATTR_RO(in_intr_mask);
423 static ssize_t in_read_index_show(struct device *dev,
424 struct device_attribute *dev_attr, char *buf)
426 struct hv_device *hv_dev = device_to_hv_device(dev);
427 struct hv_ring_buffer_debug_info inbound;
430 if (!hv_dev->channel)
433 ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
437 return sprintf(buf, "%d\n", inbound.current_read_index);
439 static DEVICE_ATTR_RO(in_read_index);
441 static ssize_t in_write_index_show(struct device *dev,
442 struct device_attribute *dev_attr, char *buf)
444 struct hv_device *hv_dev = device_to_hv_device(dev);
445 struct hv_ring_buffer_debug_info inbound;
448 if (!hv_dev->channel)
451 ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
455 return sprintf(buf, "%d\n", inbound.current_write_index);
457 static DEVICE_ATTR_RO(in_write_index);
459 static ssize_t in_read_bytes_avail_show(struct device *dev,
460 struct device_attribute *dev_attr,
463 struct hv_device *hv_dev = device_to_hv_device(dev);
464 struct hv_ring_buffer_debug_info inbound;
467 if (!hv_dev->channel)
470 ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
474 return sprintf(buf, "%d\n", inbound.bytes_avail_toread);
476 static DEVICE_ATTR_RO(in_read_bytes_avail);
478 static ssize_t in_write_bytes_avail_show(struct device *dev,
479 struct device_attribute *dev_attr,
482 struct hv_device *hv_dev = device_to_hv_device(dev);
483 struct hv_ring_buffer_debug_info inbound;
486 if (!hv_dev->channel)
489 ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
493 return sprintf(buf, "%d\n", inbound.bytes_avail_towrite);
495 static DEVICE_ATTR_RO(in_write_bytes_avail);
497 static ssize_t channel_vp_mapping_show(struct device *dev,
498 struct device_attribute *dev_attr,
501 struct hv_device *hv_dev = device_to_hv_device(dev);
502 struct vmbus_channel *channel = hv_dev->channel, *cur_sc;
504 int buf_size = PAGE_SIZE, n_written, tot_written;
505 struct list_head *cur;
510 tot_written = snprintf(buf, buf_size, "%u:%u\n",
511 channel->offermsg.child_relid, channel->target_cpu);
513 spin_lock_irqsave(&channel->lock, flags);
515 list_for_each(cur, &channel->sc_list) {
516 if (tot_written >= buf_size - 1)
519 cur_sc = list_entry(cur, struct vmbus_channel, sc_list);
520 n_written = scnprintf(buf + tot_written,
521 buf_size - tot_written,
523 cur_sc->offermsg.child_relid,
525 tot_written += n_written;
528 spin_unlock_irqrestore(&channel->lock, flags);
532 static DEVICE_ATTR_RO(channel_vp_mapping);
534 static ssize_t vendor_show(struct device *dev,
535 struct device_attribute *dev_attr,
538 struct hv_device *hv_dev = device_to_hv_device(dev);
539 return sprintf(buf, "0x%x\n", hv_dev->vendor_id);
541 static DEVICE_ATTR_RO(vendor);
543 static ssize_t device_show(struct device *dev,
544 struct device_attribute *dev_attr,
547 struct hv_device *hv_dev = device_to_hv_device(dev);
548 return sprintf(buf, "0x%x\n", hv_dev->device_id);
550 static DEVICE_ATTR_RO(device);
552 static ssize_t driver_override_store(struct device *dev,
553 struct device_attribute *attr,
554 const char *buf, size_t count)
556 struct hv_device *hv_dev = device_to_hv_device(dev);
557 char *driver_override, *old, *cp;
559 /* We need to keep extra room for a newline */
560 if (count >= (PAGE_SIZE - 1))
563 driver_override = kstrndup(buf, count, GFP_KERNEL);
564 if (!driver_override)
567 cp = strchr(driver_override, '\n');
572 old = hv_dev->driver_override;
573 if (strlen(driver_override)) {
574 hv_dev->driver_override = driver_override;
576 kfree(driver_override);
577 hv_dev->driver_override = NULL;
586 static ssize_t driver_override_show(struct device *dev,
587 struct device_attribute *attr, char *buf)
589 struct hv_device *hv_dev = device_to_hv_device(dev);
593 len = snprintf(buf, PAGE_SIZE, "%s\n", hv_dev->driver_override);
598 static DEVICE_ATTR_RW(driver_override);
600 /* Set up per device attributes in /sys/bus/vmbus/devices/<bus device> */
601 static struct attribute *vmbus_dev_attrs[] = {
603 &dev_attr_state.attr,
604 &dev_attr_monitor_id.attr,
605 &dev_attr_class_id.attr,
606 &dev_attr_device_id.attr,
607 &dev_attr_modalias.attr,
609 &dev_attr_numa_node.attr,
611 &dev_attr_server_monitor_pending.attr,
612 &dev_attr_client_monitor_pending.attr,
613 &dev_attr_server_monitor_latency.attr,
614 &dev_attr_client_monitor_latency.attr,
615 &dev_attr_server_monitor_conn_id.attr,
616 &dev_attr_client_monitor_conn_id.attr,
617 &dev_attr_out_intr_mask.attr,
618 &dev_attr_out_read_index.attr,
619 &dev_attr_out_write_index.attr,
620 &dev_attr_out_read_bytes_avail.attr,
621 &dev_attr_out_write_bytes_avail.attr,
622 &dev_attr_in_intr_mask.attr,
623 &dev_attr_in_read_index.attr,
624 &dev_attr_in_write_index.attr,
625 &dev_attr_in_read_bytes_avail.attr,
626 &dev_attr_in_write_bytes_avail.attr,
627 &dev_attr_channel_vp_mapping.attr,
628 &dev_attr_vendor.attr,
629 &dev_attr_device.attr,
630 &dev_attr_driver_override.attr,
635 * Device-level attribute_group callback function. Returns the permission for
636 * each attribute, and returns 0 if an attribute is not visible.
638 static umode_t vmbus_dev_attr_is_visible(struct kobject *kobj,
639 struct attribute *attr, int idx)
641 struct device *dev = kobj_to_dev(kobj);
642 const struct hv_device *hv_dev = device_to_hv_device(dev);
644 /* Hide the monitor attributes if the monitor mechanism is not used. */
645 if (!hv_dev->channel->offermsg.monitor_allocated &&
646 (attr == &dev_attr_monitor_id.attr ||
647 attr == &dev_attr_server_monitor_pending.attr ||
648 attr == &dev_attr_client_monitor_pending.attr ||
649 attr == &dev_attr_server_monitor_latency.attr ||
650 attr == &dev_attr_client_monitor_latency.attr ||
651 attr == &dev_attr_server_monitor_conn_id.attr ||
652 attr == &dev_attr_client_monitor_conn_id.attr))
658 static const struct attribute_group vmbus_dev_group = {
659 .attrs = vmbus_dev_attrs,
660 .is_visible = vmbus_dev_attr_is_visible
662 __ATTRIBUTE_GROUPS(vmbus_dev);
665 * vmbus_uevent - add uevent for our device
667 * This routine is invoked when a device is added or removed on the vmbus to
668 * generate a uevent to udev in the userspace. The udev will then look at its
669 * rule and the uevent generated here to load the appropriate driver
671 * The alias string will be of the form vmbus:guid where guid is the string
672 * representation of the device guid (each byte of the guid will be
673 * represented with two hex characters.
675 static int vmbus_uevent(struct device *device, struct kobj_uevent_env *env)
677 struct hv_device *dev = device_to_hv_device(device);
679 char alias_name[VMBUS_ALIAS_LEN + 1];
681 print_alias_name(dev, alias_name);
682 ret = add_uevent_var(env, "MODALIAS=vmbus:%s", alias_name);
686 static const struct hv_vmbus_device_id *
687 hv_vmbus_dev_match(const struct hv_vmbus_device_id *id, const guid_t *guid)
690 return NULL; /* empty device table */
692 for (; !guid_is_null(&id->guid); id++)
693 if (guid_equal(&id->guid, guid))
699 static const struct hv_vmbus_device_id *
700 hv_vmbus_dynid_match(struct hv_driver *drv, const guid_t *guid)
702 const struct hv_vmbus_device_id *id = NULL;
703 struct vmbus_dynid *dynid;
705 spin_lock(&drv->dynids.lock);
706 list_for_each_entry(dynid, &drv->dynids.list, node) {
707 if (guid_equal(&dynid->id.guid, guid)) {
712 spin_unlock(&drv->dynids.lock);
717 static const struct hv_vmbus_device_id vmbus_device_null;
720 * Return a matching hv_vmbus_device_id pointer.
721 * If there is no match, return NULL.
723 static const struct hv_vmbus_device_id *hv_vmbus_get_id(struct hv_driver *drv,
724 struct hv_device *dev)
726 const guid_t *guid = &dev->dev_type;
727 const struct hv_vmbus_device_id *id;
729 /* When driver_override is set, only bind to the matching driver */
730 if (dev->driver_override && strcmp(dev->driver_override, drv->name))
733 /* Look at the dynamic ids first, before the static ones */
734 id = hv_vmbus_dynid_match(drv, guid);
736 id = hv_vmbus_dev_match(drv->id_table, guid);
738 /* driver_override will always match, send a dummy id */
739 if (!id && dev->driver_override)
740 id = &vmbus_device_null;
745 /* vmbus_add_dynid - add a new device ID to this driver and re-probe devices */
746 static int vmbus_add_dynid(struct hv_driver *drv, guid_t *guid)
748 struct vmbus_dynid *dynid;
750 dynid = kzalloc(sizeof(*dynid), GFP_KERNEL);
754 dynid->id.guid = *guid;
756 spin_lock(&drv->dynids.lock);
757 list_add_tail(&dynid->node, &drv->dynids.list);
758 spin_unlock(&drv->dynids.lock);
760 return driver_attach(&drv->driver);
763 static void vmbus_free_dynids(struct hv_driver *drv)
765 struct vmbus_dynid *dynid, *n;
767 spin_lock(&drv->dynids.lock);
768 list_for_each_entry_safe(dynid, n, &drv->dynids.list, node) {
769 list_del(&dynid->node);
772 spin_unlock(&drv->dynids.lock);
776 * store_new_id - sysfs frontend to vmbus_add_dynid()
778 * Allow GUIDs to be added to an existing driver via sysfs.
780 static ssize_t new_id_store(struct device_driver *driver, const char *buf,
783 struct hv_driver *drv = drv_to_hv_drv(driver);
787 retval = guid_parse(buf, &guid);
791 if (hv_vmbus_dynid_match(drv, &guid))
794 retval = vmbus_add_dynid(drv, &guid);
799 static DRIVER_ATTR_WO(new_id);
802 * store_remove_id - remove a PCI device ID from this driver
804 * Removes a dynamic pci device ID to this driver.
806 static ssize_t remove_id_store(struct device_driver *driver, const char *buf,
809 struct hv_driver *drv = drv_to_hv_drv(driver);
810 struct vmbus_dynid *dynid, *n;
814 retval = guid_parse(buf, &guid);
819 spin_lock(&drv->dynids.lock);
820 list_for_each_entry_safe(dynid, n, &drv->dynids.list, node) {
821 struct hv_vmbus_device_id *id = &dynid->id;
823 if (guid_equal(&id->guid, &guid)) {
824 list_del(&dynid->node);
830 spin_unlock(&drv->dynids.lock);
834 static DRIVER_ATTR_WO(remove_id);
836 static struct attribute *vmbus_drv_attrs[] = {
837 &driver_attr_new_id.attr,
838 &driver_attr_remove_id.attr,
841 ATTRIBUTE_GROUPS(vmbus_drv);
845 * vmbus_match - Attempt to match the specified device to the specified driver
847 static int vmbus_match(struct device *device, struct device_driver *driver)
849 struct hv_driver *drv = drv_to_hv_drv(driver);
850 struct hv_device *hv_dev = device_to_hv_device(device);
852 /* The hv_sock driver handles all hv_sock offers. */
853 if (is_hvsock_channel(hv_dev->channel))
856 if (hv_vmbus_get_id(drv, hv_dev))
863 * vmbus_probe - Add the new vmbus's child device
865 static int vmbus_probe(struct device *child_device)
868 struct hv_driver *drv =
869 drv_to_hv_drv(child_device->driver);
870 struct hv_device *dev = device_to_hv_device(child_device);
871 const struct hv_vmbus_device_id *dev_id;
873 dev_id = hv_vmbus_get_id(drv, dev);
875 ret = drv->probe(dev, dev_id);
877 pr_err("probe failed for device %s (%d)\n",
878 dev_name(child_device), ret);
881 pr_err("probe not set for driver %s\n",
882 dev_name(child_device));
889 * vmbus_remove - Remove a vmbus device
891 static int vmbus_remove(struct device *child_device)
893 struct hv_driver *drv;
894 struct hv_device *dev = device_to_hv_device(child_device);
896 if (child_device->driver) {
897 drv = drv_to_hv_drv(child_device->driver);
907 * vmbus_shutdown - Shutdown a vmbus device
909 static void vmbus_shutdown(struct device *child_device)
911 struct hv_driver *drv;
912 struct hv_device *dev = device_to_hv_device(child_device);
915 /* The device may not be attached yet */
916 if (!child_device->driver)
919 drv = drv_to_hv_drv(child_device->driver);
927 * vmbus_device_release - Final callback release of the vmbus child device
929 static void vmbus_device_release(struct device *device)
931 struct hv_device *hv_dev = device_to_hv_device(device);
932 struct vmbus_channel *channel = hv_dev->channel;
934 mutex_lock(&vmbus_connection.channel_mutex);
935 hv_process_channel_removal(channel);
936 mutex_unlock(&vmbus_connection.channel_mutex);
940 /* The one and only one */
941 static struct bus_type hv_bus = {
943 .match = vmbus_match,
944 .shutdown = vmbus_shutdown,
945 .remove = vmbus_remove,
946 .probe = vmbus_probe,
947 .uevent = vmbus_uevent,
948 .dev_groups = vmbus_dev_groups,
949 .drv_groups = vmbus_drv_groups,
952 struct onmessage_work_context {
953 struct work_struct work;
954 struct hv_message msg;
957 static void vmbus_onmessage_work(struct work_struct *work)
959 struct onmessage_work_context *ctx;
961 /* Do not process messages if we're in DISCONNECTED state */
962 if (vmbus_connection.conn_state == DISCONNECTED)
965 ctx = container_of(work, struct onmessage_work_context,
967 vmbus_onmessage(&ctx->msg);
971 static void hv_process_timer_expiration(struct hv_message *msg,
972 struct hv_per_cpu_context *hv_cpu)
974 struct clock_event_device *dev = hv_cpu->clk_evt;
976 if (dev->event_handler)
977 dev->event_handler(dev);
979 vmbus_signal_eom(msg, HVMSG_TIMER_EXPIRED);
982 void vmbus_on_msg_dpc(unsigned long data)
984 struct hv_per_cpu_context *hv_cpu = (void *)data;
985 void *page_addr = hv_cpu->synic_message_page;
986 struct hv_message *msg = (struct hv_message *)page_addr +
988 struct vmbus_channel_message_header *hdr;
989 const struct vmbus_channel_message_table_entry *entry;
990 struct onmessage_work_context *ctx;
991 u32 message_type = msg->header.message_type;
993 if (message_type == HVMSG_NONE)
997 hdr = (struct vmbus_channel_message_header *)msg->u.payload;
999 trace_vmbus_on_msg_dpc(hdr);
1001 if (hdr->msgtype >= CHANNELMSG_COUNT) {
1002 WARN_ONCE(1, "unknown msgtype=%d\n", hdr->msgtype);
1006 entry = &channel_message_table[hdr->msgtype];
1007 if (entry->handler_type == VMHT_BLOCKING) {
1008 ctx = kmalloc(sizeof(*ctx), GFP_ATOMIC);
1012 INIT_WORK(&ctx->work, vmbus_onmessage_work);
1013 memcpy(&ctx->msg, msg, sizeof(*msg));
1016 * The host can generate a rescind message while we
1017 * may still be handling the original offer. We deal with
1018 * this condition by ensuring the processing is done on the
1021 switch (hdr->msgtype) {
1022 case CHANNELMSG_RESCIND_CHANNELOFFER:
1024 * If we are handling the rescind message;
1025 * schedule the work on the global work queue.
1027 schedule_work_on(vmbus_connection.connect_cpu,
1031 case CHANNELMSG_OFFERCHANNEL:
1032 atomic_inc(&vmbus_connection.offer_in_progress);
1033 queue_work_on(vmbus_connection.connect_cpu,
1034 vmbus_connection.work_queue,
1039 queue_work(vmbus_connection.work_queue, &ctx->work);
1042 entry->message_handler(hdr);
1045 vmbus_signal_eom(msg, message_type);
1050 * Direct callback for channels using other deferred processing
1052 static void vmbus_channel_isr(struct vmbus_channel *channel)
1054 void (*callback_fn)(void *);
1056 callback_fn = READ_ONCE(channel->onchannel_callback);
1057 if (likely(callback_fn != NULL))
1058 (*callback_fn)(channel->channel_callback_context);
1062 * Schedule all channels with events pending
1064 static void vmbus_chan_sched(struct hv_per_cpu_context *hv_cpu)
1066 unsigned long *recv_int_page;
1069 if (vmbus_proto_version < VERSION_WIN8) {
1070 maxbits = MAX_NUM_CHANNELS_SUPPORTED;
1071 recv_int_page = vmbus_connection.recv_int_page;
1074 * When the host is win8 and beyond, the event page
1075 * can be directly checked to get the id of the channel
1076 * that has the interrupt pending.
1078 void *page_addr = hv_cpu->synic_event_page;
1079 union hv_synic_event_flags *event
1080 = (union hv_synic_event_flags *)page_addr +
1083 maxbits = HV_EVENT_FLAGS_COUNT;
1084 recv_int_page = event->flags;
1087 if (unlikely(!recv_int_page))
1090 for_each_set_bit(relid, recv_int_page, maxbits) {
1091 struct vmbus_channel *channel;
1093 if (!sync_test_and_clear_bit(relid, recv_int_page))
1096 /* Special case - vmbus channel protocol msg */
1102 /* Find channel based on relid */
1103 list_for_each_entry_rcu(channel, &hv_cpu->chan_list, percpu_list) {
1104 if (channel->offermsg.child_relid != relid)
1107 if (channel->rescind)
1110 trace_vmbus_chan_sched(channel);
1112 ++channel->interrupts;
1114 switch (channel->callback_mode) {
1116 vmbus_channel_isr(channel);
1119 case HV_CALL_BATCHED:
1120 hv_begin_read(&channel->inbound);
1122 case HV_CALL_DIRECT:
1123 tasklet_schedule(&channel->callback_event);
1131 static void vmbus_isr(void)
1133 struct hv_per_cpu_context *hv_cpu
1134 = this_cpu_ptr(hv_context.cpu_context);
1135 void *page_addr = hv_cpu->synic_event_page;
1136 struct hv_message *msg;
1137 union hv_synic_event_flags *event;
1138 bool handled = false;
1140 if (unlikely(page_addr == NULL))
1143 event = (union hv_synic_event_flags *)page_addr +
1146 * Check for events before checking for messages. This is the order
1147 * in which events and messages are checked in Windows guests on
1148 * Hyper-V, and the Windows team suggested we do the same.
1151 if ((vmbus_proto_version == VERSION_WS2008) ||
1152 (vmbus_proto_version == VERSION_WIN7)) {
1154 /* Since we are a child, we only need to check bit 0 */
1155 if (sync_test_and_clear_bit(0, event->flags))
1159 * Our host is win8 or above. The signaling mechanism
1160 * has changed and we can directly look at the event page.
1161 * If bit n is set then we have an interrup on the channel
1168 vmbus_chan_sched(hv_cpu);
1170 page_addr = hv_cpu->synic_message_page;
1171 msg = (struct hv_message *)page_addr + VMBUS_MESSAGE_SINT;
1173 /* Check if there are actual msgs to be processed */
1174 if (msg->header.message_type != HVMSG_NONE) {
1175 if (msg->header.message_type == HVMSG_TIMER_EXPIRED)
1176 hv_process_timer_expiration(msg, hv_cpu);
1178 tasklet_schedule(&hv_cpu->msg_dpc);
1181 add_interrupt_randomness(HYPERVISOR_CALLBACK_VECTOR, 0);
1185 * Boolean to control whether to report panic messages over Hyper-V.
1187 * It can be set via /proc/sys/kernel/hyperv/record_panic_msg
1189 static int sysctl_record_panic_msg = 1;
1192 * Callback from kmsg_dump. Grab as much as possible from the end of the kmsg
1193 * buffer and call into Hyper-V to transfer the data.
1195 static void hv_kmsg_dump(struct kmsg_dumper *dumper,
1196 enum kmsg_dump_reason reason)
1198 size_t bytes_written;
1199 phys_addr_t panic_pa;
1201 /* We are only interested in panics. */
1202 if ((reason != KMSG_DUMP_PANIC) || (!sysctl_record_panic_msg))
1205 panic_pa = virt_to_phys(hv_panic_page);
1208 * Write dump contents to the page. No need to synchronize; panic should
1209 * be single-threaded.
1211 kmsg_dump_get_buffer(dumper, true, hv_panic_page, PAGE_SIZE,
1214 hyperv_report_panic_msg(panic_pa, bytes_written);
1217 static struct kmsg_dumper hv_kmsg_dumper = {
1218 .dump = hv_kmsg_dump,
1221 static struct ctl_table_header *hv_ctl_table_hdr;
1226 * sysctl option to allow the user to control whether kmsg data should be
1227 * reported to Hyper-V on panic.
1229 static struct ctl_table hv_ctl_table[] = {
1231 .procname = "hyperv_record_panic_msg",
1232 .data = &sysctl_record_panic_msg,
1233 .maxlen = sizeof(int),
1235 .proc_handler = proc_dointvec_minmax,
1242 static struct ctl_table hv_root_table[] = {
1244 .procname = "kernel",
1246 .child = hv_ctl_table
1252 * vmbus_bus_init -Main vmbus driver initialization routine.
1255 * - initialize the vmbus driver context
1256 * - invoke the vmbus hv main init routine
1257 * - retrieve the channel offers
1259 static int vmbus_bus_init(void)
1263 /* Hypervisor initialization...setup hypercall page..etc */
1266 pr_err("Unable to initialize the hypervisor - 0x%x\n", ret);
1270 ret = bus_register(&hv_bus);
1274 hv_setup_vmbus_irq(vmbus_isr);
1276 ret = hv_synic_alloc();
1280 * Initialize the per-cpu interrupt state and
1281 * connect to the host.
1283 ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "hyperv/vmbus:online",
1284 hv_synic_init, hv_synic_cleanup);
1287 hyperv_cpuhp_online = ret;
1289 ret = vmbus_connect();
1294 * Only register if the crash MSRs are available
1296 if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE) {
1297 u64 hyperv_crash_ctl;
1299 * Sysctl registration is not fatal, since by default
1300 * reporting is enabled.
1302 hv_ctl_table_hdr = register_sysctl_table(hv_root_table);
1303 if (!hv_ctl_table_hdr)
1304 pr_err("Hyper-V: sysctl table register error");
1307 * Register for panic kmsg callback only if the right
1308 * capability is supported by the hypervisor.
1310 hv_get_crash_ctl(hyperv_crash_ctl);
1311 if (hyperv_crash_ctl & HV_CRASH_CTL_CRASH_NOTIFY_MSG) {
1312 hv_panic_page = (void *)get_zeroed_page(GFP_KERNEL);
1313 if (hv_panic_page) {
1314 ret = kmsg_dump_register(&hv_kmsg_dumper);
1316 pr_err("Hyper-V: kmsg dump register "
1317 "error 0x%x\n", ret);
1319 pr_err("Hyper-V: panic message page memory "
1320 "allocation failed");
1323 register_die_notifier(&hyperv_die_block);
1324 atomic_notifier_chain_register(&panic_notifier_list,
1325 &hyperv_panic_block);
1328 vmbus_request_offers();
1333 cpuhp_remove_state(hyperv_cpuhp_online);
1336 hv_remove_vmbus_irq();
1338 bus_unregister(&hv_bus);
1339 free_page((unsigned long)hv_panic_page);
1340 unregister_sysctl_table(hv_ctl_table_hdr);
1341 hv_ctl_table_hdr = NULL;
1346 * __vmbus_child_driver_register() - Register a vmbus's driver
1347 * @hv_driver: Pointer to driver structure you want to register
1348 * @owner: owner module of the drv
1349 * @mod_name: module name string
1351 * Registers the given driver with Linux through the 'driver_register()' call
1352 * and sets up the hyper-v vmbus handling for this driver.
1353 * It will return the state of the 'driver_register()' call.
1356 int __vmbus_driver_register(struct hv_driver *hv_driver, struct module *owner, const char *mod_name)
1360 pr_info("registering driver %s\n", hv_driver->name);
1362 ret = vmbus_exists();
1366 hv_driver->driver.name = hv_driver->name;
1367 hv_driver->driver.owner = owner;
1368 hv_driver->driver.mod_name = mod_name;
1369 hv_driver->driver.bus = &hv_bus;
1371 spin_lock_init(&hv_driver->dynids.lock);
1372 INIT_LIST_HEAD(&hv_driver->dynids.list);
1374 ret = driver_register(&hv_driver->driver);
1378 EXPORT_SYMBOL_GPL(__vmbus_driver_register);
1381 * vmbus_driver_unregister() - Unregister a vmbus's driver
1382 * @hv_driver: Pointer to driver structure you want to
1385 * Un-register the given driver that was previous registered with a call to
1386 * vmbus_driver_register()
1388 void vmbus_driver_unregister(struct hv_driver *hv_driver)
1390 pr_info("unregistering driver %s\n", hv_driver->name);
1392 if (!vmbus_exists()) {
1393 driver_unregister(&hv_driver->driver);
1394 vmbus_free_dynids(hv_driver);
1397 EXPORT_SYMBOL_GPL(vmbus_driver_unregister);
1401 * Called when last reference to channel is gone.
1403 static void vmbus_chan_release(struct kobject *kobj)
1405 struct vmbus_channel *channel
1406 = container_of(kobj, struct vmbus_channel, kobj);
1408 kfree_rcu(channel, rcu);
1411 struct vmbus_chan_attribute {
1412 struct attribute attr;
1413 ssize_t (*show)(struct vmbus_channel *chan, char *buf);
1414 ssize_t (*store)(struct vmbus_channel *chan,
1415 const char *buf, size_t count);
1417 #define VMBUS_CHAN_ATTR(_name, _mode, _show, _store) \
1418 struct vmbus_chan_attribute chan_attr_##_name \
1419 = __ATTR(_name, _mode, _show, _store)
1420 #define VMBUS_CHAN_ATTR_RW(_name) \
1421 struct vmbus_chan_attribute chan_attr_##_name = __ATTR_RW(_name)
1422 #define VMBUS_CHAN_ATTR_RO(_name) \
1423 struct vmbus_chan_attribute chan_attr_##_name = __ATTR_RO(_name)
1424 #define VMBUS_CHAN_ATTR_WO(_name) \
1425 struct vmbus_chan_attribute chan_attr_##_name = __ATTR_WO(_name)
1427 static ssize_t vmbus_chan_attr_show(struct kobject *kobj,
1428 struct attribute *attr, char *buf)
1430 const struct vmbus_chan_attribute *attribute
1431 = container_of(attr, struct vmbus_chan_attribute, attr);
1432 struct vmbus_channel *chan
1433 = container_of(kobj, struct vmbus_channel, kobj);
1435 if (!attribute->show)
1438 return attribute->show(chan, buf);
1441 static const struct sysfs_ops vmbus_chan_sysfs_ops = {
1442 .show = vmbus_chan_attr_show,
1445 static ssize_t out_mask_show(struct vmbus_channel *channel, char *buf)
1447 struct hv_ring_buffer_info *rbi = &channel->outbound;
1450 mutex_lock(&rbi->ring_buffer_mutex);
1451 if (!rbi->ring_buffer) {
1452 mutex_unlock(&rbi->ring_buffer_mutex);
1456 ret = sprintf(buf, "%u\n", rbi->ring_buffer->interrupt_mask);
1457 mutex_unlock(&rbi->ring_buffer_mutex);
1460 static VMBUS_CHAN_ATTR_RO(out_mask);
1462 static ssize_t in_mask_show(struct vmbus_channel *channel, char *buf)
1464 struct hv_ring_buffer_info *rbi = &channel->inbound;
1467 mutex_lock(&rbi->ring_buffer_mutex);
1468 if (!rbi->ring_buffer) {
1469 mutex_unlock(&rbi->ring_buffer_mutex);
1473 ret = sprintf(buf, "%u\n", rbi->ring_buffer->interrupt_mask);
1474 mutex_unlock(&rbi->ring_buffer_mutex);
1477 static VMBUS_CHAN_ATTR_RO(in_mask);
1479 static ssize_t read_avail_show(struct vmbus_channel *channel, char *buf)
1481 struct hv_ring_buffer_info *rbi = &channel->inbound;
1484 mutex_lock(&rbi->ring_buffer_mutex);
1485 if (!rbi->ring_buffer) {
1486 mutex_unlock(&rbi->ring_buffer_mutex);
1490 ret = sprintf(buf, "%u\n", hv_get_bytes_to_read(rbi));
1491 mutex_unlock(&rbi->ring_buffer_mutex);
1494 static VMBUS_CHAN_ATTR_RO(read_avail);
1496 static ssize_t write_avail_show(struct vmbus_channel *channel, char *buf)
1498 struct hv_ring_buffer_info *rbi = &channel->outbound;
1501 mutex_lock(&rbi->ring_buffer_mutex);
1502 if (!rbi->ring_buffer) {
1503 mutex_unlock(&rbi->ring_buffer_mutex);
1507 ret = sprintf(buf, "%u\n", hv_get_bytes_to_write(rbi));
1508 mutex_unlock(&rbi->ring_buffer_mutex);
1511 static VMBUS_CHAN_ATTR_RO(write_avail);
1513 static ssize_t show_target_cpu(struct vmbus_channel *channel, char *buf)
1515 return sprintf(buf, "%u\n", channel->target_cpu);
1517 static VMBUS_CHAN_ATTR(cpu, S_IRUGO, show_target_cpu, NULL);
1519 static ssize_t channel_pending_show(struct vmbus_channel *channel,
1522 return sprintf(buf, "%d\n",
1523 channel_pending(channel,
1524 vmbus_connection.monitor_pages[1]));
1526 static VMBUS_CHAN_ATTR(pending, S_IRUGO, channel_pending_show, NULL);
1528 static ssize_t channel_latency_show(struct vmbus_channel *channel,
1531 return sprintf(buf, "%d\n",
1532 channel_latency(channel,
1533 vmbus_connection.monitor_pages[1]));
1535 static VMBUS_CHAN_ATTR(latency, S_IRUGO, channel_latency_show, NULL);
1537 static ssize_t channel_interrupts_show(struct vmbus_channel *channel, char *buf)
1539 return sprintf(buf, "%llu\n", channel->interrupts);
1541 static VMBUS_CHAN_ATTR(interrupts, S_IRUGO, channel_interrupts_show, NULL);
1543 static ssize_t channel_events_show(struct vmbus_channel *channel, char *buf)
1545 return sprintf(buf, "%llu\n", channel->sig_events);
1547 static VMBUS_CHAN_ATTR(events, S_IRUGO, channel_events_show, NULL);
1549 static ssize_t channel_intr_in_full_show(struct vmbus_channel *channel,
1552 return sprintf(buf, "%llu\n",
1553 (unsigned long long)channel->intr_in_full);
1555 static VMBUS_CHAN_ATTR(intr_in_full, 0444, channel_intr_in_full_show, NULL);
1557 static ssize_t channel_intr_out_empty_show(struct vmbus_channel *channel,
1560 return sprintf(buf, "%llu\n",
1561 (unsigned long long)channel->intr_out_empty);
1563 static VMBUS_CHAN_ATTR(intr_out_empty, 0444, channel_intr_out_empty_show, NULL);
1565 static ssize_t channel_out_full_first_show(struct vmbus_channel *channel,
1568 return sprintf(buf, "%llu\n",
1569 (unsigned long long)channel->out_full_first);
1571 static VMBUS_CHAN_ATTR(out_full_first, 0444, channel_out_full_first_show, NULL);
1573 static ssize_t channel_out_full_total_show(struct vmbus_channel *channel,
1576 return sprintf(buf, "%llu\n",
1577 (unsigned long long)channel->out_full_total);
1579 static VMBUS_CHAN_ATTR(out_full_total, 0444, channel_out_full_total_show, NULL);
1581 static ssize_t subchannel_monitor_id_show(struct vmbus_channel *channel,
1584 return sprintf(buf, "%u\n", channel->offermsg.monitorid);
1586 static VMBUS_CHAN_ATTR(monitor_id, S_IRUGO, subchannel_monitor_id_show, NULL);
1588 static ssize_t subchannel_id_show(struct vmbus_channel *channel,
1591 return sprintf(buf, "%u\n",
1592 channel->offermsg.offer.sub_channel_index);
1594 static VMBUS_CHAN_ATTR_RO(subchannel_id);
1596 static struct attribute *vmbus_chan_attrs[] = {
1597 &chan_attr_out_mask.attr,
1598 &chan_attr_in_mask.attr,
1599 &chan_attr_read_avail.attr,
1600 &chan_attr_write_avail.attr,
1601 &chan_attr_cpu.attr,
1602 &chan_attr_pending.attr,
1603 &chan_attr_latency.attr,
1604 &chan_attr_interrupts.attr,
1605 &chan_attr_events.attr,
1606 &chan_attr_intr_in_full.attr,
1607 &chan_attr_intr_out_empty.attr,
1608 &chan_attr_out_full_first.attr,
1609 &chan_attr_out_full_total.attr,
1610 &chan_attr_monitor_id.attr,
1611 &chan_attr_subchannel_id.attr,
1616 * Channel-level attribute_group callback function. Returns the permission for
1617 * each attribute, and returns 0 if an attribute is not visible.
1619 static umode_t vmbus_chan_attr_is_visible(struct kobject *kobj,
1620 struct attribute *attr, int idx)
1622 const struct vmbus_channel *channel =
1623 container_of(kobj, struct vmbus_channel, kobj);
1625 /* Hide the monitor attributes if the monitor mechanism is not used. */
1626 if (!channel->offermsg.monitor_allocated &&
1627 (attr == &chan_attr_pending.attr ||
1628 attr == &chan_attr_latency.attr ||
1629 attr == &chan_attr_monitor_id.attr))
1635 static struct attribute_group vmbus_chan_group = {
1636 .attrs = vmbus_chan_attrs,
1637 .is_visible = vmbus_chan_attr_is_visible
1640 static struct kobj_type vmbus_chan_ktype = {
1641 .sysfs_ops = &vmbus_chan_sysfs_ops,
1642 .release = vmbus_chan_release,
1646 * vmbus_add_channel_kobj - setup a sub-directory under device/channels
1648 int vmbus_add_channel_kobj(struct hv_device *dev, struct vmbus_channel *channel)
1650 const struct device *device = &dev->device;
1651 struct kobject *kobj = &channel->kobj;
1652 u32 relid = channel->offermsg.child_relid;
1655 kobj->kset = dev->channels_kset;
1656 ret = kobject_init_and_add(kobj, &vmbus_chan_ktype, NULL,
1661 ret = sysfs_create_group(kobj, &vmbus_chan_group);
1665 * The calling functions' error handling paths will cleanup the
1666 * empty channel directory.
1668 dev_err(device, "Unable to set up channel sysfs files\n");
1672 kobject_uevent(kobj, KOBJ_ADD);
1678 * vmbus_remove_channel_attr_group - remove the channel's attribute group
1680 void vmbus_remove_channel_attr_group(struct vmbus_channel *channel)
1682 sysfs_remove_group(&channel->kobj, &vmbus_chan_group);
1686 * vmbus_device_create - Creates and registers a new child device
1689 struct hv_device *vmbus_device_create(const guid_t *type,
1690 const guid_t *instance,
1691 struct vmbus_channel *channel)
1693 struct hv_device *child_device_obj;
1695 child_device_obj = kzalloc(sizeof(struct hv_device), GFP_KERNEL);
1696 if (!child_device_obj) {
1697 pr_err("Unable to allocate device object for child device\n");
1701 child_device_obj->channel = channel;
1702 guid_copy(&child_device_obj->dev_type, type);
1703 guid_copy(&child_device_obj->dev_instance, instance);
1704 child_device_obj->vendor_id = 0x1414; /* MSFT vendor ID */
1706 return child_device_obj;
1710 * vmbus_device_register - Register the child device
1712 int vmbus_device_register(struct hv_device *child_device_obj)
1714 struct kobject *kobj = &child_device_obj->device.kobj;
1717 dev_set_name(&child_device_obj->device, "%pUl",
1718 child_device_obj->channel->offermsg.offer.if_instance.b);
1720 child_device_obj->device.bus = &hv_bus;
1721 child_device_obj->device.parent = &hv_acpi_dev->dev;
1722 child_device_obj->device.release = vmbus_device_release;
1725 * Register with the LDM. This will kick off the driver/device
1726 * binding...which will eventually call vmbus_match() and vmbus_probe()
1728 ret = device_register(&child_device_obj->device);
1730 pr_err("Unable to register child device\n");
1734 child_device_obj->channels_kset = kset_create_and_add("channels",
1736 if (!child_device_obj->channels_kset) {
1738 goto err_dev_unregister;
1741 ret = vmbus_add_channel_kobj(child_device_obj,
1742 child_device_obj->channel);
1744 pr_err("Unable to register primary channeln");
1745 goto err_kset_unregister;
1750 err_kset_unregister:
1751 kset_unregister(child_device_obj->channels_kset);
1754 device_unregister(&child_device_obj->device);
1759 * vmbus_device_unregister - Remove the specified child device
1762 void vmbus_device_unregister(struct hv_device *device_obj)
1764 pr_debug("child device %s unregistered\n",
1765 dev_name(&device_obj->device));
1767 kset_unregister(device_obj->channels_kset);
1770 * Kick off the process of unregistering the device.
1771 * This will call vmbus_remove() and eventually vmbus_device_release()
1773 device_unregister(&device_obj->device);
1778 * VMBUS is an acpi enumerated device. Get the information we
1781 #define VTPM_BASE_ADDRESS 0xfed40000
1782 static acpi_status vmbus_walk_resources(struct acpi_resource *res, void *ctx)
1784 resource_size_t start = 0;
1785 resource_size_t end = 0;
1786 struct resource *new_res;
1787 struct resource **old_res = &hyperv_mmio;
1788 struct resource **prev_res = NULL;
1790 switch (res->type) {
1793 * "Address" descriptors are for bus windows. Ignore
1794 * "memory" descriptors, which are for registers on
1797 case ACPI_RESOURCE_TYPE_ADDRESS32:
1798 start = res->data.address32.address.minimum;
1799 end = res->data.address32.address.maximum;
1802 case ACPI_RESOURCE_TYPE_ADDRESS64:
1803 start = res->data.address64.address.minimum;
1804 end = res->data.address64.address.maximum;
1808 /* Unused resource type */
1813 * Ignore ranges that are below 1MB, as they're not
1814 * necessary or useful here.
1819 new_res = kzalloc(sizeof(*new_res), GFP_ATOMIC);
1821 return AE_NO_MEMORY;
1823 /* If this range overlaps the virtual TPM, truncate it. */
1824 if (end > VTPM_BASE_ADDRESS && start < VTPM_BASE_ADDRESS)
1825 end = VTPM_BASE_ADDRESS;
1827 new_res->name = "hyperv mmio";
1828 new_res->flags = IORESOURCE_MEM;
1829 new_res->start = start;
1833 * If two ranges are adjacent, merge them.
1841 if (((*old_res)->end + 1) == new_res->start) {
1842 (*old_res)->end = new_res->end;
1847 if ((*old_res)->start == new_res->end + 1) {
1848 (*old_res)->start = new_res->start;
1853 if ((*old_res)->start > new_res->end) {
1854 new_res->sibling = *old_res;
1856 (*prev_res)->sibling = new_res;
1862 old_res = &(*old_res)->sibling;
1869 static int vmbus_acpi_remove(struct acpi_device *device)
1871 struct resource *cur_res;
1872 struct resource *next_res;
1876 __release_region(hyperv_mmio, fb_mmio->start,
1877 resource_size(fb_mmio));
1881 for (cur_res = hyperv_mmio; cur_res; cur_res = next_res) {
1882 next_res = cur_res->sibling;
1890 static void vmbus_reserve_fb(void)
1894 * Make a claim for the frame buffer in the resource tree under the
1895 * first node, which will be the one below 4GB. The length seems to
1896 * be underreported, particularly in a Generation 1 VM. So start out
1897 * reserving a larger area and make it smaller until it succeeds.
1900 if (screen_info.lfb_base) {
1901 if (efi_enabled(EFI_BOOT))
1902 size = max_t(__u32, screen_info.lfb_size, 0x800000);
1904 size = max_t(__u32, screen_info.lfb_size, 0x4000000);
1906 for (; !fb_mmio && (size >= 0x100000); size >>= 1) {
1907 fb_mmio = __request_region(hyperv_mmio,
1908 screen_info.lfb_base, size,
1915 * vmbus_allocate_mmio() - Pick a memory-mapped I/O range.
1916 * @new: If successful, supplied a pointer to the
1917 * allocated MMIO space.
1918 * @device_obj: Identifies the caller
1919 * @min: Minimum guest physical address of the
1921 * @max: Maximum guest physical address
1922 * @size: Size of the range to be allocated
1923 * @align: Alignment of the range to be allocated
1924 * @fb_overlap_ok: Whether this allocation can be allowed
1925 * to overlap the video frame buffer.
1927 * This function walks the resources granted to VMBus by the
1928 * _CRS object in the ACPI namespace underneath the parent
1929 * "bridge" whether that's a root PCI bus in the Generation 1
1930 * case or a Module Device in the Generation 2 case. It then
1931 * attempts to allocate from the global MMIO pool in a way that
1932 * matches the constraints supplied in these parameters and by
1935 * Return: 0 on success, -errno on failure
1937 int vmbus_allocate_mmio(struct resource **new, struct hv_device *device_obj,
1938 resource_size_t min, resource_size_t max,
1939 resource_size_t size, resource_size_t align,
1942 struct resource *iter, *shadow;
1943 resource_size_t range_min, range_max, start;
1944 const char *dev_n = dev_name(&device_obj->device);
1948 down(&hyperv_mmio_lock);
1951 * If overlaps with frame buffers are allowed, then first attempt to
1952 * make the allocation from within the reserved region. Because it
1953 * is already reserved, no shadow allocation is necessary.
1955 if (fb_overlap_ok && fb_mmio && !(min > fb_mmio->end) &&
1956 !(max < fb_mmio->start)) {
1958 range_min = fb_mmio->start;
1959 range_max = fb_mmio->end;
1960 start = (range_min + align - 1) & ~(align - 1);
1961 for (; start + size - 1 <= range_max; start += align) {
1962 *new = request_mem_region_exclusive(start, size, dev_n);
1970 for (iter = hyperv_mmio; iter; iter = iter->sibling) {
1971 if ((iter->start >= max) || (iter->end <= min))
1974 range_min = iter->start;
1975 range_max = iter->end;
1976 start = (range_min + align - 1) & ~(align - 1);
1977 for (; start + size - 1 <= range_max; start += align) {
1978 shadow = __request_region(iter, start, size, NULL,
1983 *new = request_mem_region_exclusive(start, size, dev_n);
1985 shadow->name = (char *)*new;
1990 __release_region(iter, start, size);
1995 up(&hyperv_mmio_lock);
1998 EXPORT_SYMBOL_GPL(vmbus_allocate_mmio);
2001 * vmbus_free_mmio() - Free a memory-mapped I/O range.
2002 * @start: Base address of region to release.
2003 * @size: Size of the range to be allocated
2005 * This function releases anything requested by
2006 * vmbus_mmio_allocate().
2008 void vmbus_free_mmio(resource_size_t start, resource_size_t size)
2010 struct resource *iter;
2012 down(&hyperv_mmio_lock);
2013 for (iter = hyperv_mmio; iter; iter = iter->sibling) {
2014 if ((iter->start >= start + size) || (iter->end <= start))
2017 __release_region(iter, start, size);
2019 release_mem_region(start, size);
2020 up(&hyperv_mmio_lock);
2023 EXPORT_SYMBOL_GPL(vmbus_free_mmio);
2025 static int vmbus_acpi_add(struct acpi_device *device)
2028 int ret_val = -ENODEV;
2029 struct acpi_device *ancestor;
2031 hv_acpi_dev = device;
2033 result = acpi_walk_resources(device->handle, METHOD_NAME__CRS,
2034 vmbus_walk_resources, NULL);
2036 if (ACPI_FAILURE(result))
2039 * Some ancestor of the vmbus acpi device (Gen1 or Gen2
2040 * firmware) is the VMOD that has the mmio ranges. Get that.
2042 for (ancestor = device->parent; ancestor; ancestor = ancestor->parent) {
2043 result = acpi_walk_resources(ancestor->handle, METHOD_NAME__CRS,
2044 vmbus_walk_resources, NULL);
2046 if (ACPI_FAILURE(result))
2056 complete(&probe_event);
2058 vmbus_acpi_remove(device);
2062 static const struct acpi_device_id vmbus_acpi_device_ids[] = {
2067 MODULE_DEVICE_TABLE(acpi, vmbus_acpi_device_ids);
2069 static struct acpi_driver vmbus_acpi_driver = {
2071 .ids = vmbus_acpi_device_ids,
2073 .add = vmbus_acpi_add,
2074 .remove = vmbus_acpi_remove,
2078 static void hv_kexec_handler(void)
2080 hv_synic_clockevents_cleanup();
2081 vmbus_initiate_unload(false);
2082 vmbus_connection.conn_state = DISCONNECTED;
2083 /* Make sure conn_state is set as hv_synic_cleanup checks for it */
2085 cpuhp_remove_state(hyperv_cpuhp_online);
2089 static void hv_crash_handler(struct pt_regs *regs)
2091 vmbus_initiate_unload(true);
2093 * In crash handler we can't schedule synic cleanup for all CPUs,
2094 * doing the cleanup for current CPU only. This should be sufficient
2097 vmbus_connection.conn_state = DISCONNECTED;
2098 hv_synic_cleanup(smp_processor_id());
2102 static int __init hv_acpi_init(void)
2106 if (!hv_is_hyperv_initialized())
2109 init_completion(&probe_event);
2112 * Get ACPI resources first.
2114 ret = acpi_bus_register_driver(&vmbus_acpi_driver);
2119 t = wait_for_completion_timeout(&probe_event, 5*HZ);
2125 ret = vmbus_bus_init();
2129 hv_setup_kexec_handler(hv_kexec_handler);
2130 hv_setup_crash_handler(hv_crash_handler);
2135 acpi_bus_unregister_driver(&vmbus_acpi_driver);
2140 static void __exit vmbus_exit(void)
2144 hv_remove_kexec_handler();
2145 hv_remove_crash_handler();
2146 vmbus_connection.conn_state = DISCONNECTED;
2147 hv_synic_clockevents_cleanup();
2149 hv_remove_vmbus_irq();
2150 for_each_online_cpu(cpu) {
2151 struct hv_per_cpu_context *hv_cpu
2152 = per_cpu_ptr(hv_context.cpu_context, cpu);
2154 tasklet_kill(&hv_cpu->msg_dpc);
2156 vmbus_free_channels();
2158 if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE) {
2159 kmsg_dump_unregister(&hv_kmsg_dumper);
2160 unregister_die_notifier(&hyperv_die_block);
2161 atomic_notifier_chain_unregister(&panic_notifier_list,
2162 &hyperv_panic_block);
2165 free_page((unsigned long)hv_panic_page);
2166 unregister_sysctl_table(hv_ctl_table_hdr);
2167 hv_ctl_table_hdr = NULL;
2168 bus_unregister(&hv_bus);
2170 cpuhp_remove_state(hyperv_cpuhp_online);
2172 acpi_bus_unregister_driver(&vmbus_acpi_driver);
2176 MODULE_LICENSE("GPL");
2178 subsys_initcall(hv_acpi_init);
2179 module_exit(vmbus_exit);