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626b901f60
linux-next/drivers/hv/vmbus_drv.c
Michael Kelley 626b901f60 Drivers: hv: vmbus: Add parsing of VMbus interrupt in ACPI DSDT 
On ARM64, Hyper-V now specifies the interrupt to be used by VMbus
in the ACPI DSDT.  This information is not used on x86 because the
interrupt vector must be hardcoded.  But update the generic
VMbus driver to do the parsing and pass the information to the
architecture specific code that sets up the Linux IRQ.  Update
consumers of the interrupt to get it from an architecture specific
function.

Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/1597434304-40631-1-git-send-email-mikelley@microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-10-14 19:14:51 +00:00

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// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (c) 2009, Microsoft Corporation.
*
* Authors:
* Haiyang Zhang <haiyangz@microsoft.com>
* Hank Janssen <hjanssen@microsoft.com>
* K. Y. Srinivasan <kys@microsoft.com>
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/init.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/interrupt.h>
#include <linux/sysctl.h>
#include <linux/slab.h>
#include <linux/acpi.h>
#include <linux/completion.h>
#include <linux/hyperv.h>
#include <linux/kernel_stat.h>
#include <linux/clockchips.h>
#include <linux/cpu.h>
#include <linux/sched/task_stack.h>
#include <linux/delay.h>
#include <linux/notifier.h>
#include <linux/ptrace.h>
#include <linux/screen_info.h>
#include <linux/kdebug.h>
#include <linux/efi.h>
#include <linux/random.h>
#include <linux/kernel.h>
#include <linux/syscore_ops.h>
#include <clocksource/hyperv_timer.h>
#include "hyperv_vmbus.h"
struct vmbus_dynid {
struct list_head node;
struct hv_vmbus_device_id id;
};
static struct acpi_device *hv_acpi_dev;
static struct completion probe_event;
static int hyperv_cpuhp_online;
static void *hv_panic_page;
/* Values parsed from ACPI DSDT */
static int vmbus_irq;
int vmbus_interrupt;
/*
* Boolean to control whether to report panic messages over Hyper-V.
*
* It can be set via /proc/sys/kernel/hyperv/record_panic_msg
*/
static int sysctl_record_panic_msg = 1;
static int hyperv_report_reg(void)
{
return !sysctl_record_panic_msg || !hv_panic_page;
}
static int hyperv_panic_event(struct notifier_block *nb, unsigned long val,
void *args)
{
struct pt_regs *regs;
vmbus_initiate_unload(true);
/*
* Hyper-V should be notified only once about a panic. If we will be
* doing hyperv_report_panic_msg() later with kmsg data, don't do
* the notification here.
*/
if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE
&& hyperv_report_reg()) {
regs = current_pt_regs();
hyperv_report_panic(regs, val, false);
}
return NOTIFY_DONE;
}
static int hyperv_die_event(struct notifier_block *nb, unsigned long val,
void *args)
{
struct die_args *die = args;
struct pt_regs *regs = die->regs;
/* Don't notify Hyper-V if the die event is other than oops */
if (val != DIE_OOPS)
return NOTIFY_DONE;
/*
* Hyper-V should be notified only once about a panic. If we will be
* doing hyperv_report_panic_msg() later with kmsg data, don't do
* the notification here.
*/
if (hyperv_report_reg())
hyperv_report_panic(regs, val, true);
return NOTIFY_DONE;
}
static struct notifier_block hyperv_die_block = {
.notifier_call = hyperv_die_event,
};
static struct notifier_block hyperv_panic_block = {
.notifier_call = hyperv_panic_event,
};
static const char *fb_mmio_name = "fb_range";
static struct resource *fb_mmio;
static struct resource *hyperv_mmio;
static DEFINE_MUTEX(hyperv_mmio_lock);
static int vmbus_exists(void)
{
if (hv_acpi_dev == NULL)
return -ENODEV;
return 0;
}
static u8 channel_monitor_group(const struct vmbus_channel *channel)
{
return (u8)channel->offermsg.monitorid / 32;
}
static u8 channel_monitor_offset(const struct vmbus_channel *channel)
{
return (u8)channel->offermsg.monitorid % 32;
}
static u32 channel_pending(const struct vmbus_channel *channel,
const struct hv_monitor_page *monitor_page)
{
u8 monitor_group = channel_monitor_group(channel);
return monitor_page->trigger_group[monitor_group].pending;
}
static u32 channel_latency(const struct vmbus_channel *channel,
const struct hv_monitor_page *monitor_page)
{
u8 monitor_group = channel_monitor_group(channel);
u8 monitor_offset = channel_monitor_offset(channel);
return monitor_page->latency[monitor_group][monitor_offset];
}
static u32 channel_conn_id(struct vmbus_channel *channel,
struct hv_monitor_page *monitor_page)
{
u8 monitor_group = channel_monitor_group(channel);
u8 monitor_offset = channel_monitor_offset(channel);
return monitor_page->parameter[monitor_group][monitor_offset].connectionid.u.id;
}
static ssize_t id_show(struct device *dev, struct device_attribute *dev_attr,
char *buf)
{
struct hv_device *hv_dev = device_to_hv_device(dev);
if (!hv_dev->channel)
return -ENODEV;
return sprintf(buf, "%d\n", hv_dev->channel->offermsg.child_relid);
}
static DEVICE_ATTR_RO(id);
static ssize_t state_show(struct device *dev, struct device_attribute *dev_attr,
char *buf)
{
struct hv_device *hv_dev = device_to_hv_device(dev);
if (!hv_dev->channel)
return -ENODEV;
return sprintf(buf, "%d\n", hv_dev->channel->state);
}
static DEVICE_ATTR_RO(state);
static ssize_t monitor_id_show(struct device *dev,
struct device_attribute *dev_attr, char *buf)
{
struct hv_device *hv_dev = device_to_hv_device(dev);
if (!hv_dev->channel)
return -ENODEV;
return sprintf(buf, "%d\n", hv_dev->channel->offermsg.monitorid);
}
static DEVICE_ATTR_RO(monitor_id);
static ssize_t class_id_show(struct device *dev,
struct device_attribute *dev_attr, char *buf)
{
struct hv_device *hv_dev = device_to_hv_device(dev);
if (!hv_dev->channel)
return -ENODEV;
return sprintf(buf, "{%pUl}\n",
&hv_dev->channel->offermsg.offer.if_type);
}
static DEVICE_ATTR_RO(class_id);
static ssize_t device_id_show(struct device *dev,
struct device_attribute *dev_attr, char *buf)
{
struct hv_device *hv_dev = device_to_hv_device(dev);
if (!hv_dev->channel)
return -ENODEV;
return sprintf(buf, "{%pUl}\n",
&hv_dev->channel->offermsg.offer.if_instance);
}
static DEVICE_ATTR_RO(device_id);
static ssize_t modalias_show(struct device *dev,
struct device_attribute *dev_attr, char *buf)
{
struct hv_device *hv_dev = device_to_hv_device(dev);
return sprintf(buf, "vmbus:%*phN\n", UUID_SIZE, &hv_dev->dev_type);
}
static DEVICE_ATTR_RO(modalias);
#ifdef CONFIG_NUMA
static ssize_t numa_node_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct hv_device *hv_dev = device_to_hv_device(dev);
if (!hv_dev->channel)
return -ENODEV;
return sprintf(buf, "%d\n", cpu_to_node(hv_dev->channel->target_cpu));
}
static DEVICE_ATTR_RO(numa_node);
#endif
static ssize_t server_monitor_pending_show(struct device *dev,
struct device_attribute *dev_attr,
char *buf)
{
struct hv_device *hv_dev = device_to_hv_device(dev);
if (!hv_dev->channel)
return -ENODEV;
return sprintf(buf, "%d\n",
channel_pending(hv_dev->channel,
vmbus_connection.monitor_pages[0]));
}
static DEVICE_ATTR_RO(server_monitor_pending);
static ssize_t client_monitor_pending_show(struct device *dev,
struct device_attribute *dev_attr,
char *buf)
{
struct hv_device *hv_dev = device_to_hv_device(dev);
if (!hv_dev->channel)
return -ENODEV;
return sprintf(buf, "%d\n",
channel_pending(hv_dev->channel,
vmbus_connection.monitor_pages[1]));
}
static DEVICE_ATTR_RO(client_monitor_pending);
static ssize_t server_monitor_latency_show(struct device *dev,
struct device_attribute *dev_attr,
char *buf)
{
struct hv_device *hv_dev = device_to_hv_device(dev);
if (!hv_dev->channel)
return -ENODEV;
return sprintf(buf, "%d\n",
channel_latency(hv_dev->channel,
vmbus_connection.monitor_pages[0]));
}
static DEVICE_ATTR_RO(server_monitor_latency);
static ssize_t client_monitor_latency_show(struct device *dev,
struct device_attribute *dev_attr,
char *buf)
{
struct hv_device *hv_dev = device_to_hv_device(dev);
if (!hv_dev->channel)
return -ENODEV;
return sprintf(buf, "%d\n",
channel_latency(hv_dev->channel,
vmbus_connection.monitor_pages[1]));
}
static DEVICE_ATTR_RO(client_monitor_latency);
static ssize_t server_monitor_conn_id_show(struct device *dev,
struct device_attribute *dev_attr,
char *buf)
{
struct hv_device *hv_dev = device_to_hv_device(dev);
if (!hv_dev->channel)
return -ENODEV;
return sprintf(buf, "%d\n",
channel_conn_id(hv_dev->channel,
vmbus_connection.monitor_pages[0]));
}
static DEVICE_ATTR_RO(server_monitor_conn_id);
static ssize_t client_monitor_conn_id_show(struct device *dev,
struct device_attribute *dev_attr,
char *buf)
{
struct hv_device *hv_dev = device_to_hv_device(dev);
if (!hv_dev->channel)
return -ENODEV;
return sprintf(buf, "%d\n",
channel_conn_id(hv_dev->channel,
vmbus_connection.monitor_pages[1]));
}
static DEVICE_ATTR_RO(client_monitor_conn_id);
static ssize_t out_intr_mask_show(struct device *dev,
struct device_attribute *dev_attr, char *buf)
{
struct hv_device *hv_dev = device_to_hv_device(dev);
struct hv_ring_buffer_debug_info outbound;
int ret;
if (!hv_dev->channel)
return -ENODEV;
ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound,
&outbound);
if (ret < 0)
return ret;
return sprintf(buf, "%d\n", outbound.current_interrupt_mask);
}
static DEVICE_ATTR_RO(out_intr_mask);
static ssize_t out_read_index_show(struct device *dev,
struct device_attribute *dev_attr, char *buf)
{
struct hv_device *hv_dev = device_to_hv_device(dev);
struct hv_ring_buffer_debug_info outbound;
int ret;
if (!hv_dev->channel)
return -ENODEV;
ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound,
&outbound);
if (ret < 0)
return ret;
return sprintf(buf, "%d\n", outbound.current_read_index);
}
static DEVICE_ATTR_RO(out_read_index);
static ssize_t out_write_index_show(struct device *dev,
struct device_attribute *dev_attr,
char *buf)
{
struct hv_device *hv_dev = device_to_hv_device(dev);
struct hv_ring_buffer_debug_info outbound;
int ret;
if (!hv_dev->channel)
return -ENODEV;
ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound,
&outbound);
if (ret < 0)
return ret;
return sprintf(buf, "%d\n", outbound.current_write_index);
}
static DEVICE_ATTR_RO(out_write_index);
static ssize_t out_read_bytes_avail_show(struct device *dev,
struct device_attribute *dev_attr,
char *buf)
{
struct hv_device *hv_dev = device_to_hv_device(dev);
struct hv_ring_buffer_debug_info outbound;
int ret;
if (!hv_dev->channel)
return -ENODEV;
ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound,
&outbound);
if (ret < 0)
return ret;
return sprintf(buf, "%d\n", outbound.bytes_avail_toread);
}
static DEVICE_ATTR_RO(out_read_bytes_avail);
static ssize_t out_write_bytes_avail_show(struct device *dev,
struct device_attribute *dev_attr,
char *buf)
{
struct hv_device *hv_dev = device_to_hv_device(dev);
struct hv_ring_buffer_debug_info outbound;
int ret;
if (!hv_dev->channel)
return -ENODEV;
ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound,
&outbound);
if (ret < 0)
return ret;
return sprintf(buf, "%d\n", outbound.bytes_avail_towrite);
}
static DEVICE_ATTR_RO(out_write_bytes_avail);
static ssize_t in_intr_mask_show(struct device *dev,
struct device_attribute *dev_attr, char *buf)
{
struct hv_device *hv_dev = device_to_hv_device(dev);
struct hv_ring_buffer_debug_info inbound;
int ret;
if (!hv_dev->channel)
return -ENODEV;
ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
if (ret < 0)
return ret;
return sprintf(buf, "%d\n", inbound.current_interrupt_mask);
}
static DEVICE_ATTR_RO(in_intr_mask);
static ssize_t in_read_index_show(struct device *dev,
struct device_attribute *dev_attr, char *buf)
{
struct hv_device *hv_dev = device_to_hv_device(dev);
struct hv_ring_buffer_debug_info inbound;
int ret;
if (!hv_dev->channel)
return -ENODEV;
ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
if (ret < 0)
return ret;
return sprintf(buf, "%d\n", inbound.current_read_index);
}
static DEVICE_ATTR_RO(in_read_index);
static ssize_t in_write_index_show(struct device *dev,
struct device_attribute *dev_attr, char *buf)
{
struct hv_device *hv_dev = device_to_hv_device(dev);
struct hv_ring_buffer_debug_info inbound;
int ret;
if (!hv_dev->channel)
return -ENODEV;
ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
if (ret < 0)
return ret;
return sprintf(buf, "%d\n", inbound.current_write_index);
}
static DEVICE_ATTR_RO(in_write_index);
static ssize_t in_read_bytes_avail_show(struct device *dev,
struct device_attribute *dev_attr,
char *buf)
{
struct hv_device *hv_dev = device_to_hv_device(dev);
struct hv_ring_buffer_debug_info inbound;
int ret;
if (!hv_dev->channel)
return -ENODEV;
ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
if (ret < 0)
return ret;
return sprintf(buf, "%d\n", inbound.bytes_avail_toread);
}
static DEVICE_ATTR_RO(in_read_bytes_avail);
static ssize_t in_write_bytes_avail_show(struct device *dev,
struct device_attribute *dev_attr,
char *buf)
{
struct hv_device *hv_dev = device_to_hv_device(dev);
struct hv_ring_buffer_debug_info inbound;
int ret;
if (!hv_dev->channel)
return -ENODEV;
ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
if (ret < 0)
return ret;
return sprintf(buf, "%d\n", inbound.bytes_avail_towrite);
}
static DEVICE_ATTR_RO(in_write_bytes_avail);
static ssize_t channel_vp_mapping_show(struct device *dev,
struct device_attribute *dev_attr,
char *buf)
{
struct hv_device *hv_dev = device_to_hv_device(dev);
struct vmbus_channel *channel = hv_dev->channel, *cur_sc;
int buf_size = PAGE_SIZE, n_written, tot_written;
struct list_head *cur;
if (!channel)
return -ENODEV;
mutex_lock(&vmbus_connection.channel_mutex);
tot_written = snprintf(buf, buf_size, "%u:%u\n",
channel->offermsg.child_relid, channel->target_cpu);
list_for_each(cur, &channel->sc_list) {
if (tot_written >= buf_size - 1)
break;
cur_sc = list_entry(cur, struct vmbus_channel, sc_list);
n_written = scnprintf(buf + tot_written,
buf_size - tot_written,
"%u:%u\n",
cur_sc->offermsg.child_relid,
cur_sc->target_cpu);
tot_written += n_written;
}
mutex_unlock(&vmbus_connection.channel_mutex);
return tot_written;
}
static DEVICE_ATTR_RO(channel_vp_mapping);
static ssize_t vendor_show(struct device *dev,
struct device_attribute *dev_attr,
char *buf)
{
struct hv_device *hv_dev = device_to_hv_device(dev);
return sprintf(buf, "0x%x\n", hv_dev->vendor_id);
}
static DEVICE_ATTR_RO(vendor);
static ssize_t device_show(struct device *dev,
struct device_attribute *dev_attr,
char *buf)
{
struct hv_device *hv_dev = device_to_hv_device(dev);
return sprintf(buf, "0x%x\n", hv_dev->device_id);
}
static DEVICE_ATTR_RO(device);
static ssize_t driver_override_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct hv_device *hv_dev = device_to_hv_device(dev);
char *driver_override, *old, *cp;
/* We need to keep extra room for a newline */
if (count >= (PAGE_SIZE - 1))
return -EINVAL;
driver_override = kstrndup(buf, count, GFP_KERNEL);
if (!driver_override)
return -ENOMEM;
cp = strchr(driver_override, '\n');
if (cp)
*cp = '\0';
device_lock(dev);
old = hv_dev->driver_override;
if (strlen(driver_override)) {
hv_dev->driver_override = driver_override;
} else {
kfree(driver_override);
hv_dev->driver_override = NULL;
}
device_unlock(dev);
kfree(old);
return count;
}
static ssize_t driver_override_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct hv_device *hv_dev = device_to_hv_device(dev);
ssize_t len;
device_lock(dev);
len = snprintf(buf, PAGE_SIZE, "%s\n", hv_dev->driver_override);
device_unlock(dev);
return len;
}
static DEVICE_ATTR_RW(driver_override);
/* Set up per device attributes in /sys/bus/vmbus/devices/<bus device> */
static struct attribute *vmbus_dev_attrs[] = {
&dev_attr_id.attr,
&dev_attr_state.attr,
&dev_attr_monitor_id.attr,
&dev_attr_class_id.attr,
&dev_attr_device_id.attr,
&dev_attr_modalias.attr,
#ifdef CONFIG_NUMA
&dev_attr_numa_node.attr,
#endif
&dev_attr_server_monitor_pending.attr,
&dev_attr_client_monitor_pending.attr,
&dev_attr_server_monitor_latency.attr,
&dev_attr_client_monitor_latency.attr,
&dev_attr_server_monitor_conn_id.attr,
&dev_attr_client_monitor_conn_id.attr,
&dev_attr_out_intr_mask.attr,
&dev_attr_out_read_index.attr,
&dev_attr_out_write_index.attr,
&dev_attr_out_read_bytes_avail.attr,
&dev_attr_out_write_bytes_avail.attr,
&dev_attr_in_intr_mask.attr,
&dev_attr_in_read_index.attr,
&dev_attr_in_write_index.attr,
&dev_attr_in_read_bytes_avail.attr,
&dev_attr_in_write_bytes_avail.attr,
&dev_attr_channel_vp_mapping.attr,
&dev_attr_vendor.attr,
&dev_attr_device.attr,
&dev_attr_driver_override.attr,
NULL,
};
/*
* Device-level attribute_group callback function. Returns the permission for
* each attribute, and returns 0 if an attribute is not visible.
*/
static umode_t vmbus_dev_attr_is_visible(struct kobject *kobj,
struct attribute *attr, int idx)
{
struct device *dev = kobj_to_dev(kobj);
const struct hv_device *hv_dev = device_to_hv_device(dev);
/* Hide the monitor attributes if the monitor mechanism is not used. */
if (!hv_dev->channel->offermsg.monitor_allocated &&
(attr == &dev_attr_monitor_id.attr ||
attr == &dev_attr_server_monitor_pending.attr ||
attr == &dev_attr_client_monitor_pending.attr ||
attr == &dev_attr_server_monitor_latency.attr ||
attr == &dev_attr_client_monitor_latency.attr ||
attr == &dev_attr_server_monitor_conn_id.attr ||
attr == &dev_attr_client_monitor_conn_id.attr))
return 0;
return attr->mode;
}
static const struct attribute_group vmbus_dev_group = {
.attrs = vmbus_dev_attrs,
.is_visible = vmbus_dev_attr_is_visible
};
__ATTRIBUTE_GROUPS(vmbus_dev);
/*
* vmbus_uevent - add uevent for our device
*
* This routine is invoked when a device is added or removed on the vmbus to
* generate a uevent to udev in the userspace. The udev will then look at its
* rule and the uevent generated here to load the appropriate driver
*
* The alias string will be of the form vmbus:guid where guid is the string
* representation of the device guid (each byte of the guid will be
* represented with two hex characters.
*/
static int vmbus_uevent(struct device *device, struct kobj_uevent_env *env)
{
struct hv_device *dev = device_to_hv_device(device);
const char *format = "MODALIAS=vmbus:%*phN";
return add_uevent_var(env, format, UUID_SIZE, &dev->dev_type);
}
static const struct hv_vmbus_device_id *
hv_vmbus_dev_match(const struct hv_vmbus_device_id *id, const guid_t *guid)
{
if (id == NULL)
return NULL; /* empty device table */
for (; !guid_is_null(&id->guid); id++)
if (guid_equal(&id->guid, guid))
return id;
return NULL;
}
static const struct hv_vmbus_device_id *
hv_vmbus_dynid_match(struct hv_driver *drv, const guid_t *guid)
{
const struct hv_vmbus_device_id *id = NULL;
struct vmbus_dynid *dynid;
spin_lock(&drv->dynids.lock);
list_for_each_entry(dynid, &drv->dynids.list, node) {
if (guid_equal(&dynid->id.guid, guid)) {
id = &dynid->id;
break;
}
}
spin_unlock(&drv->dynids.lock);
return id;
}
static const struct hv_vmbus_device_id vmbus_device_null;
/*
* Return a matching hv_vmbus_device_id pointer.
* If there is no match, return NULL.
*/
static const struct hv_vmbus_device_id *hv_vmbus_get_id(struct hv_driver *drv,
struct hv_device *dev)
{
const guid_t *guid = &dev->dev_type;
const struct hv_vmbus_device_id *id;
/* When driver_override is set, only bind to the matching driver */
if (dev->driver_override && strcmp(dev->driver_override, drv->name))
return NULL;
/* Look at the dynamic ids first, before the static ones */
id = hv_vmbus_dynid_match(drv, guid);
if (!id)
id = hv_vmbus_dev_match(drv->id_table, guid);
/* driver_override will always match, send a dummy id */
if (!id && dev->driver_override)
id = &vmbus_device_null;
return id;
}
/* vmbus_add_dynid - add a new device ID to this driver and re-probe devices */
static int vmbus_add_dynid(struct hv_driver *drv, guid_t *guid)
{
struct vmbus_dynid *dynid;
dynid = kzalloc(sizeof(*dynid), GFP_KERNEL);
if (!dynid)
return -ENOMEM;
dynid->id.guid = *guid;
spin_lock(&drv->dynids.lock);
list_add_tail(&dynid->node, &drv->dynids.list);
spin_unlock(&drv->dynids.lock);
return driver_attach(&drv->driver);
}
static void vmbus_free_dynids(struct hv_driver *drv)
{
struct vmbus_dynid *dynid, *n;
spin_lock(&drv->dynids.lock);
list_for_each_entry_safe(dynid, n, &drv->dynids.list, node) {
list_del(&dynid->node);
kfree(dynid);
}
spin_unlock(&drv->dynids.lock);
}
/*
* store_new_id - sysfs frontend to vmbus_add_dynid()
*
* Allow GUIDs to be added to an existing driver via sysfs.
*/
static ssize_t new_id_store(struct device_driver *driver, const char *buf,
size_t count)
{
struct hv_driver *drv = drv_to_hv_drv(driver);
guid_t guid;
ssize_t retval;
retval = guid_parse(buf, &guid);
if (retval)
return retval;
if (hv_vmbus_dynid_match(drv, &guid))
return -EEXIST;
retval = vmbus_add_dynid(drv, &guid);
if (retval)
return retval;
return count;
}
static DRIVER_ATTR_WO(new_id);
/*
* store_remove_id - remove a PCI device ID from this driver
*
* Removes a dynamic pci device ID to this driver.
*/
static ssize_t remove_id_store(struct device_driver *driver, const char *buf,
size_t count)
{
struct hv_driver *drv = drv_to_hv_drv(driver);
struct vmbus_dynid *dynid, *n;
guid_t guid;
ssize_t retval;
retval = guid_parse(buf, &guid);
if (retval)
return retval;
retval = -ENODEV;
spin_lock(&drv->dynids.lock);
list_for_each_entry_safe(dynid, n, &drv->dynids.list, node) {
struct hv_vmbus_device_id *id = &dynid->id;
if (guid_equal(&id->guid, &guid)) {
list_del(&dynid->node);
kfree(dynid);
retval = count;
break;
}
}
spin_unlock(&drv->dynids.lock);
return retval;
}
static DRIVER_ATTR_WO(remove_id);
static struct attribute *vmbus_drv_attrs[] = {
&driver_attr_new_id.attr,
&driver_attr_remove_id.attr,
NULL,
};
ATTRIBUTE_GROUPS(vmbus_drv);
/*
* vmbus_match - Attempt to match the specified device to the specified driver
*/
static int vmbus_match(struct device *device, struct device_driver *driver)
{
struct hv_driver *drv = drv_to_hv_drv(driver);
struct hv_device *hv_dev = device_to_hv_device(device);
/* The hv_sock driver handles all hv_sock offers. */
if (is_hvsock_channel(hv_dev->channel))
return drv->hvsock;
if (hv_vmbus_get_id(drv, hv_dev))
return 1;
return 0;
}
/*
* vmbus_probe - Add the new vmbus's child device
*/
static int vmbus_probe(struct device *child_device)
{
int ret = 0;
struct hv_driver *drv =
drv_to_hv_drv(child_device->driver);
struct hv_device *dev = device_to_hv_device(child_device);
const struct hv_vmbus_device_id *dev_id;
dev_id = hv_vmbus_get_id(drv, dev);
if (drv->probe) {
ret = drv->probe(dev, dev_id);
if (ret != 0)
pr_err("probe failed for device %s (%d)\n",
dev_name(child_device), ret);
} else {
pr_err("probe not set for driver %s\n",
dev_name(child_device));
ret = -ENODEV;
}
return ret;
}
/*
* vmbus_remove - Remove a vmbus device
*/
static int vmbus_remove(struct device *child_device)
{
struct hv_driver *drv;
struct hv_device *dev = device_to_hv_device(child_device);
if (child_device->driver) {
drv = drv_to_hv_drv(child_device->driver);
if (drv->remove)
drv->remove(dev);
}
return 0;
}
/*
* vmbus_shutdown - Shutdown a vmbus device
*/
static void vmbus_shutdown(struct device *child_device)
{
struct hv_driver *drv;
struct hv_device *dev = device_to_hv_device(child_device);
/* The device may not be attached yet */
if (!child_device->driver)
return;
drv = drv_to_hv_drv(child_device->driver);
if (drv->shutdown)
drv->shutdown(dev);
}
#ifdef CONFIG_PM_SLEEP
/*
* vmbus_suspend - Suspend a vmbus device
*/
static int vmbus_suspend(struct device *child_device)
{
struct hv_driver *drv;
struct hv_device *dev = device_to_hv_device(child_device);
/* The device may not be attached yet */
if (!child_device->driver)
return 0;
drv = drv_to_hv_drv(child_device->driver);
if (!drv->suspend)
return -EOPNOTSUPP;
return drv->suspend(dev);
}
/*
* vmbus_resume - Resume a vmbus device
*/
static int vmbus_resume(struct device *child_device)
{
struct hv_driver *drv;
struct hv_device *dev = device_to_hv_device(child_device);
/* The device may not be attached yet */
if (!child_device->driver)
return 0;
drv = drv_to_hv_drv(child_device->driver);
if (!drv->resume)
return -EOPNOTSUPP;
return drv->resume(dev);
}
#else
#define vmbus_suspend NULL
#define vmbus_resume NULL
#endif /* CONFIG_PM_SLEEP */
/*
* vmbus_device_release - Final callback release of the vmbus child device
*/
static void vmbus_device_release(struct device *device)
{
struct hv_device *hv_dev = device_to_hv_device(device);
struct vmbus_channel *channel = hv_dev->channel;
hv_debug_rm_dev_dir(hv_dev);
mutex_lock(&vmbus_connection.channel_mutex);
hv_process_channel_removal(channel);
mutex_unlock(&vmbus_connection.channel_mutex);
kfree(hv_dev);
}
/*
* Note: we must use the "noirq" ops: see the comment before vmbus_bus_pm.
*
* suspend_noirq/resume_noirq are set to NULL to support Suspend-to-Idle: we
* shouldn't suspend the vmbus devices upon Suspend-to-Idle, otherwise there
* is no way to wake up a Generation-2 VM.
*
* The other 4 ops are for hibernation.
*/
static const struct dev_pm_ops vmbus_pm = {
.suspend_noirq = NULL,
.resume_noirq = NULL,
.freeze_noirq = vmbus_suspend,
.thaw_noirq = vmbus_resume,
.poweroff_noirq = vmbus_suspend,
.restore_noirq = vmbus_resume,
};
/* The one and only one */
static struct bus_type hv_bus = {
.name = "vmbus",
.match = vmbus_match,
.shutdown = vmbus_shutdown,
.remove = vmbus_remove,
.probe = vmbus_probe,
.uevent = vmbus_uevent,
.dev_groups = vmbus_dev_groups,
.drv_groups = vmbus_drv_groups,
.pm = &vmbus_pm,
};
struct onmessage_work_context {
struct work_struct work;
struct {
struct hv_message_header header;
u8 payload[];
} msg;
};
static void vmbus_onmessage_work(struct work_struct *work)
{
struct onmessage_work_context *ctx;
/* Do not process messages if we're in DISCONNECTED state */
if (vmbus_connection.conn_state == DISCONNECTED)
return;
ctx = container_of(work, struct onmessage_work_context,
work);
vmbus_onmessage((struct vmbus_channel_message_header *)
&ctx->msg.payload);
kfree(ctx);
}
void vmbus_on_msg_dpc(unsigned long data)
{
struct hv_per_cpu_context *hv_cpu = (void *)data;
void *page_addr = hv_cpu->synic_message_page;
struct hv_message *msg = (struct hv_message *)page_addr +
VMBUS_MESSAGE_SINT;
struct vmbus_channel_message_header *hdr;
const struct vmbus_channel_message_table_entry *entry;
struct onmessage_work_context *ctx;
u32 message_type = msg->header.message_type;
/*
* 'enum vmbus_channel_message_type' is supposed to always be 'u32' as
* it is being used in 'struct vmbus_channel_message_header' definition
* which is supposed to match hypervisor ABI.
*/
BUILD_BUG_ON(sizeof(enum vmbus_channel_message_type) != sizeof(u32));
if (message_type == HVMSG_NONE)
/* no msg */
return;
hdr = (struct vmbus_channel_message_header *)msg->u.payload;
trace_vmbus_on_msg_dpc(hdr);
if (hdr->msgtype >= CHANNELMSG_COUNT) {
WARN_ONCE(1, "unknown msgtype=%d\n", hdr->msgtype);
goto msg_handled;
}
if (msg->header.payload_size > HV_MESSAGE_PAYLOAD_BYTE_COUNT) {
WARN_ONCE(1, "payload size is too large (%d)\n",
msg->header.payload_size);
goto msg_handled;
}
entry = &channel_message_table[hdr->msgtype];
if (!entry->message_handler)
goto msg_handled;
if (msg->header.payload_size < entry->min_payload_len) {
WARN_ONCE(1, "message too short: msgtype=%d len=%d\n",
hdr->msgtype, msg->header.payload_size);
goto msg_handled;
}
if (entry->handler_type == VMHT_BLOCKING) {
ctx = kmalloc(sizeof(*ctx) + msg->header.payload_size,
GFP_ATOMIC);
if (ctx == NULL)
return;
INIT_WORK(&ctx->work, vmbus_onmessage_work);
memcpy(&ctx->msg, msg, sizeof(msg->header) +
msg->header.payload_size);
/*
* The host can generate a rescind message while we
* may still be handling the original offer. We deal with
* this condition by relying on the synchronization provided
* by offer_in_progress and by channel_mutex. See also the
* inline comments in vmbus_onoffer_rescind().
*/
switch (hdr->msgtype) {
case CHANNELMSG_RESCIND_CHANNELOFFER:
/*
* If we are handling the rescind message;
* schedule the work on the global work queue.
*
* The OFFER message and the RESCIND message should
* not be handled by the same serialized work queue,
* because the OFFER handler may call vmbus_open(),
* which tries to open the channel by sending an
* OPEN_CHANNEL message to the host and waits for
* the host's response; however, if the host has
* rescinded the channel before it receives the
* OPEN_CHANNEL message, the host just silently
* ignores the OPEN_CHANNEL message; as a result,
* the guest's OFFER handler hangs for ever, if we
* handle the RESCIND message in the same serialized
* work queue: the RESCIND handler can not start to
* run before the OFFER handler finishes.
*/
schedule_work(&ctx->work);
break;
case CHANNELMSG_OFFERCHANNEL:
/*
* The host sends the offer message of a given channel
* before sending the rescind message of the same
* channel. These messages are sent to the guest's
* connect CPU; the guest then starts processing them
* in the tasklet handler on this CPU:
*
* VMBUS_CONNECT_CPU
*
* [vmbus_on_msg_dpc()]
* atomic_inc() // CHANNELMSG_OFFERCHANNEL
* queue_work()
* ...
* [vmbus_on_msg_dpc()]
* schedule_work() // CHANNELMSG_RESCIND_CHANNELOFFER
*
* We rely on the memory-ordering properties of the
* queue_work() and schedule_work() primitives, which
* guarantee that the atomic increment will be visible
* to the CPUs which will execute the offer & rescind
* works by the time these works will start execution.
*/
atomic_inc(&vmbus_connection.offer_in_progress);
fallthrough;
default:
queue_work(vmbus_connection.work_queue, &ctx->work);
}
} else
entry->message_handler(hdr);
msg_handled:
vmbus_signal_eom(msg, message_type);
}
#ifdef CONFIG_PM_SLEEP
/*
* Fake RESCIND_CHANNEL messages to clean up hv_sock channels by force for
* hibernation, because hv_sock connections can not persist across hibernation.
*/
static void vmbus_force_channel_rescinded(struct vmbus_channel *channel)
{
struct onmessage_work_context *ctx;
struct vmbus_channel_rescind_offer *rescind;
WARN_ON(!is_hvsock_channel(channel));
/*
* Allocation size is small and the allocation should really not fail,
* otherwise the state of the hv_sock connections ends up in limbo.
*/
ctx = kzalloc(sizeof(*ctx) + sizeof(*rescind),
GFP_KERNEL | __GFP_NOFAIL);
/*
* So far, these are not really used by Linux. Just set them to the
* reasonable values conforming to the definitions of the fields.
*/
ctx->msg.header.message_type = 1;
ctx->msg.header.payload_size = sizeof(*rescind);
/* These values are actually used by Linux. */
rescind = (struct vmbus_channel_rescind_offer *)ctx->msg.payload;
rescind->header.msgtype = CHANNELMSG_RESCIND_CHANNELOFFER;
rescind->child_relid = channel->offermsg.child_relid;
INIT_WORK(&ctx->work, vmbus_onmessage_work);
queue_work(vmbus_connection.work_queue, &ctx->work);
}
#endif /* CONFIG_PM_SLEEP */
/*
* Schedule all channels with events pending
*/
static void vmbus_chan_sched(struct hv_per_cpu_context *hv_cpu)
{
unsigned long *recv_int_page;
u32 maxbits, relid;
if (vmbus_proto_version < VERSION_WIN8) {
maxbits = MAX_NUM_CHANNELS_SUPPORTED;
recv_int_page = vmbus_connection.recv_int_page;
} else {
/*
* When the host is win8 and beyond, the event page
* can be directly checked to get the id of the channel
* that has the interrupt pending.
*/
void *page_addr = hv_cpu->synic_event_page;
union hv_synic_event_flags *event
= (union hv_synic_event_flags *)page_addr +
VMBUS_MESSAGE_SINT;
maxbits = HV_EVENT_FLAGS_COUNT;
recv_int_page = event->flags;
}
if (unlikely(!recv_int_page))
return;
for_each_set_bit(relid, recv_int_page, maxbits) {
void (*callback_fn)(void *context);
struct vmbus_channel *channel;
if (!sync_test_and_clear_bit(relid, recv_int_page))
continue;
/* Special case - vmbus channel protocol msg */
if (relid == 0)
continue;
/*
* Pairs with the kfree_rcu() in vmbus_chan_release().
* Guarantees that the channel data structure doesn't
* get freed while the channel pointer below is being
* dereferenced.
*/
rcu_read_lock();
/* Find channel based on relid */
channel = relid2channel(relid);
if (channel == NULL)
goto sched_unlock_rcu;
if (channel->rescind)
goto sched_unlock_rcu;
/*
* Make sure that the ring buffer data structure doesn't get
* freed while we dereference the ring buffer pointer. Test
* for the channel's onchannel_callback being NULL within a
* sched_lock critical section. See also the inline comments
* in vmbus_reset_channel_cb().
*/
spin_lock(&channel->sched_lock);
callback_fn = channel->onchannel_callback;
if (unlikely(callback_fn == NULL))
goto sched_unlock;
trace_vmbus_chan_sched(channel);
++channel->interrupts;
switch (channel->callback_mode) {
case HV_CALL_ISR:
(*callback_fn)(channel->channel_callback_context);
break;
case HV_CALL_BATCHED:
hv_begin_read(&channel->inbound);
fallthrough;
case HV_CALL_DIRECT:
tasklet_schedule(&channel->callback_event);
}
sched_unlock:
spin_unlock(&channel->sched_lock);
sched_unlock_rcu:
rcu_read_unlock();
}
}
static void vmbus_isr(void)
{
struct hv_per_cpu_context *hv_cpu
= this_cpu_ptr(hv_context.cpu_context);
void *page_addr = hv_cpu->synic_event_page;
struct hv_message *msg;
union hv_synic_event_flags *event;
bool handled = false;
if (unlikely(page_addr == NULL))
return;
event = (union hv_synic_event_flags *)page_addr +
VMBUS_MESSAGE_SINT;
/*
* Check for events before checking for messages. This is the order
* in which events and messages are checked in Windows guests on
* Hyper-V, and the Windows team suggested we do the same.
*/
if ((vmbus_proto_version == VERSION_WS2008) ||
(vmbus_proto_version == VERSION_WIN7)) {
/* Since we are a child, we only need to check bit 0 */
if (sync_test_and_clear_bit(0, event->flags))
handled = true;
} else {
/*
* Our host is win8 or above. The signaling mechanism
* has changed and we can directly look at the event page.
* If bit n is set then we have an interrup on the channel
* whose id is n.
*/
handled = true;
}
if (handled)
vmbus_chan_sched(hv_cpu);
page_addr = hv_cpu->synic_message_page;
msg = (struct hv_message *)page_addr + VMBUS_MESSAGE_SINT;
/* Check if there are actual msgs to be processed */
if (msg->header.message_type != HVMSG_NONE) {
if (msg->header.message_type == HVMSG_TIMER_EXPIRED) {
hv_stimer0_isr();
vmbus_signal_eom(msg, HVMSG_TIMER_EXPIRED);
} else
tasklet_schedule(&hv_cpu->msg_dpc);
}
add_interrupt_randomness(hv_get_vector(), 0);
}
/*
* Callback from kmsg_dump. Grab as much as possible from the end of the kmsg
* buffer and call into Hyper-V to transfer the data.
*/
static void hv_kmsg_dump(struct kmsg_dumper *dumper,
enum kmsg_dump_reason reason)
{
size_t bytes_written;
phys_addr_t panic_pa;
/* We are only interested in panics. */
if ((reason != KMSG_DUMP_PANIC) || (!sysctl_record_panic_msg))
return;
panic_pa = virt_to_phys(hv_panic_page);
/*
* Write dump contents to the page. No need to synchronize; panic should
* be single-threaded.
*/
kmsg_dump_get_buffer(dumper, false, hv_panic_page, HV_HYP_PAGE_SIZE,
&bytes_written);
if (bytes_written)
hyperv_report_panic_msg(panic_pa, bytes_written);
}
static struct kmsg_dumper hv_kmsg_dumper = {
.dump = hv_kmsg_dump,
};
static struct ctl_table_header *hv_ctl_table_hdr;
/*
* sysctl option to allow the user to control whether kmsg data should be
* reported to Hyper-V on panic.
*/
static struct ctl_table hv_ctl_table[] = {
{
.procname = "hyperv_record_panic_msg",
.data = &sysctl_record_panic_msg,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra1 = SYSCTL_ZERO,
.extra2 = SYSCTL_ONE
},
{}
};
static struct ctl_table hv_root_table[] = {
{
.procname = "kernel",
.mode = 0555,
.child = hv_ctl_table
},
{}
};
/*
* vmbus_bus_init -Main vmbus driver initialization routine.
*
* Here, we
* - initialize the vmbus driver context
* - invoke the vmbus hv main init routine
* - retrieve the channel offers
*/
static int vmbus_bus_init(void)
{
int ret;
ret = hv_init();
if (ret != 0) {
pr_err("Unable to initialize the hypervisor - 0x%x\n", ret);
return ret;
}
ret = bus_register(&hv_bus);
if (ret)
return ret;
ret = hv_setup_vmbus_irq(vmbus_irq, vmbus_isr);
if (ret)
goto err_setup;
ret = hv_synic_alloc();
if (ret)
goto err_alloc;
/*
* Initialize the per-cpu interrupt state and stimer state.
* Then connect to the host.
*/
ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "hyperv/vmbus:online",
hv_synic_init, hv_synic_cleanup);
if (ret < 0)
goto err_cpuhp;
hyperv_cpuhp_online = ret;
ret = vmbus_connect();
if (ret)
goto err_connect;
/*
* Only register if the crash MSRs are available
*/
if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE) {
u64 hyperv_crash_ctl;
/*
* Sysctl registration is not fatal, since by default
* reporting is enabled.
*/
hv_ctl_table_hdr = register_sysctl_table(hv_root_table);
if (!hv_ctl_table_hdr)
pr_err("Hyper-V: sysctl table register error");
/*
* Register for panic kmsg callback only if the right
* capability is supported by the hypervisor.
*/
hv_get_crash_ctl(hyperv_crash_ctl);
if (hyperv_crash_ctl & HV_CRASH_CTL_CRASH_NOTIFY_MSG) {
hv_panic_page = (void *)hv_alloc_hyperv_zeroed_page();
if (hv_panic_page) {
ret = kmsg_dump_register(&hv_kmsg_dumper);
if (ret) {
pr_err("Hyper-V: kmsg dump register "
"error 0x%x\n", ret);
hv_free_hyperv_page(
(unsigned long)hv_panic_page);
hv_panic_page = NULL;
}
} else
pr_err("Hyper-V: panic message page memory "
"allocation failed");
}
register_die_notifier(&hyperv_die_block);
}
/*
* Always register the panic notifier because we need to unload
* the VMbus channel connection to prevent any VMbus
* activity after the VM panics.
*/
atomic_notifier_chain_register(&panic_notifier_list,
&hyperv_panic_block);
vmbus_request_offers();
return 0;
err_connect:
cpuhp_remove_state(hyperv_cpuhp_online);
err_cpuhp:
hv_synic_free();
err_alloc:
hv_remove_vmbus_irq();
err_setup:
bus_unregister(&hv_bus);
unregister_sysctl_table(hv_ctl_table_hdr);
hv_ctl_table_hdr = NULL;
return ret;
}
/**
* __vmbus_child_driver_register() - Register a vmbus's driver
* @hv_driver: Pointer to driver structure you want to register
* @owner: owner module of the drv
* @mod_name: module name string
*
* Registers the given driver with Linux through the 'driver_register()' call
* and sets up the hyper-v vmbus handling for this driver.
* It will return the state of the 'driver_register()' call.
*
*/
int __vmbus_driver_register(struct hv_driver *hv_driver, struct module *owner, const char *mod_name)
{
int ret;
pr_info("registering driver %s\n", hv_driver->name);
ret = vmbus_exists();
if (ret < 0)
return ret;
hv_driver->driver.name = hv_driver->name;
hv_driver->driver.owner = owner;
hv_driver->driver.mod_name = mod_name;
hv_driver->driver.bus = &hv_bus;
spin_lock_init(&hv_driver->dynids.lock);
INIT_LIST_HEAD(&hv_driver->dynids.list);
ret = driver_register(&hv_driver->driver);
return ret;
}
EXPORT_SYMBOL_GPL(__vmbus_driver_register);
/**
* vmbus_driver_unregister() - Unregister a vmbus's driver
* @hv_driver: Pointer to driver structure you want to
* un-register
*
* Un-register the given driver that was previous registered with a call to
* vmbus_driver_register()
*/
void vmbus_driver_unregister(struct hv_driver *hv_driver)
{
pr_info("unregistering driver %s\n", hv_driver->name);
if (!vmbus_exists()) {
driver_unregister(&hv_driver->driver);
vmbus_free_dynids(hv_driver);
}
}
EXPORT_SYMBOL_GPL(vmbus_driver_unregister);
/*
* Called when last reference to channel is gone.
*/
static void vmbus_chan_release(struct kobject *kobj)
{
struct vmbus_channel *channel
= container_of(kobj, struct vmbus_channel, kobj);
kfree_rcu(channel, rcu);
}
struct vmbus_chan_attribute {
struct attribute attr;
ssize_t (*show)(struct vmbus_channel *chan, char *buf);
ssize_t (*store)(struct vmbus_channel *chan,
const char *buf, size_t count);
};
#define VMBUS_CHAN_ATTR(_name, _mode, _show, _store) \
struct vmbus_chan_attribute chan_attr_##_name \
= __ATTR(_name, _mode, _show, _store)
#define VMBUS_CHAN_ATTR_RW(_name) \
struct vmbus_chan_attribute chan_attr_##_name = __ATTR_RW(_name)
#define VMBUS_CHAN_ATTR_RO(_name) \
struct vmbus_chan_attribute chan_attr_##_name = __ATTR_RO(_name)
#define VMBUS_CHAN_ATTR_WO(_name) \
struct vmbus_chan_attribute chan_attr_##_name = __ATTR_WO(_name)
static ssize_t vmbus_chan_attr_show(struct kobject *kobj,
struct attribute *attr, char *buf)
{
const struct vmbus_chan_attribute *attribute
= container_of(attr, struct vmbus_chan_attribute, attr);
struct vmbus_channel *chan
= container_of(kobj, struct vmbus_channel, kobj);
if (!attribute->show)
return -EIO;
return attribute->show(chan, buf);
}
static ssize_t vmbus_chan_attr_store(struct kobject *kobj,
struct attribute *attr, const char *buf,
size_t count)
{
const struct vmbus_chan_attribute *attribute
= container_of(attr, struct vmbus_chan_attribute, attr);
struct vmbus_channel *chan
= container_of(kobj, struct vmbus_channel, kobj);
if (!attribute->store)
return -EIO;
return attribute->store(chan, buf, count);
}
static const struct sysfs_ops vmbus_chan_sysfs_ops = {
.show = vmbus_chan_attr_show,
.store = vmbus_chan_attr_store,
};
static ssize_t out_mask_show(struct vmbus_channel *channel, char *buf)
{
struct hv_ring_buffer_info *rbi = &channel->outbound;
ssize_t ret;
mutex_lock(&rbi->ring_buffer_mutex);
if (!rbi->ring_buffer) {
mutex_unlock(&rbi->ring_buffer_mutex);
return -EINVAL;
}
ret = sprintf(buf, "%u\n", rbi->ring_buffer->interrupt_mask);
mutex_unlock(&rbi->ring_buffer_mutex);
return ret;
}
static VMBUS_CHAN_ATTR_RO(out_mask);
static ssize_t in_mask_show(struct vmbus_channel *channel, char *buf)
{
struct hv_ring_buffer_info *rbi = &channel->inbound;
ssize_t ret;
mutex_lock(&rbi->ring_buffer_mutex);
if (!rbi->ring_buffer) {
mutex_unlock(&rbi->ring_buffer_mutex);
return -EINVAL;
}
ret = sprintf(buf, "%u\n", rbi->ring_buffer->interrupt_mask);
mutex_unlock(&rbi->ring_buffer_mutex);
return ret;
}
static VMBUS_CHAN_ATTR_RO(in_mask);
static ssize_t read_avail_show(struct vmbus_channel *channel, char *buf)
{
struct hv_ring_buffer_info *rbi = &channel->inbound;
ssize_t ret;
mutex_lock(&rbi->ring_buffer_mutex);
if (!rbi->ring_buffer) {
mutex_unlock(&rbi->ring_buffer_mutex);
return -EINVAL;
}
ret = sprintf(buf, "%u\n", hv_get_bytes_to_read(rbi));
mutex_unlock(&rbi->ring_buffer_mutex);
return ret;
}
static VMBUS_CHAN_ATTR_RO(read_avail);
static ssize_t write_avail_show(struct vmbus_channel *channel, char *buf)
{
struct hv_ring_buffer_info *rbi = &channel->outbound;
ssize_t ret;
mutex_lock(&rbi->ring_buffer_mutex);
if (!rbi->ring_buffer) {
mutex_unlock(&rbi->ring_buffer_mutex);
return -EINVAL;
}
ret = sprintf(buf, "%u\n", hv_get_bytes_to_write(rbi));
mutex_unlock(&rbi->ring_buffer_mutex);
return ret;
}
static VMBUS_CHAN_ATTR_RO(write_avail);
static ssize_t target_cpu_show(struct vmbus_channel *channel, char *buf)
{
return sprintf(buf, "%u\n", channel->target_cpu);
}
static ssize_t target_cpu_store(struct vmbus_channel *channel,
const char *buf, size_t count)
{
u32 target_cpu, origin_cpu;
ssize_t ret = count;
if (vmbus_proto_version < VERSION_WIN10_V4_1)
return -EIO;
if (sscanf(buf, "%uu", &target_cpu) != 1)
return -EIO;
/* Validate target_cpu for the cpumask_test_cpu() operation below. */
if (target_cpu >= nr_cpumask_bits)
return -EINVAL;
/* No CPUs should come up or down during this. */
cpus_read_lock();
if (!cpu_online(target_cpu)) {
cpus_read_unlock();
return -EINVAL;
}
/*
* Synchronizes target_cpu_store() and channel closure:
*
* { Initially: state = CHANNEL_OPENED }
*
* CPU1 CPU2
*
* [target_cpu_store()] [vmbus_disconnect_ring()]
*
* LOCK channel_mutex LOCK channel_mutex
* LOAD r1 = state LOAD r2 = state
* IF (r1 == CHANNEL_OPENED) IF (r2 == CHANNEL_OPENED)
* SEND MODIFYCHANNEL STORE state = CHANNEL_OPEN
* [...] SEND CLOSECHANNEL
* UNLOCK channel_mutex UNLOCK channel_mutex
*
* Forbids: r1 == r2 == CHANNEL_OPENED (i.e., CPU1's LOCK precedes
* CPU2's LOCK) && CPU2's SEND precedes CPU1's SEND
*
* Note. The host processes the channel messages "sequentially", in
* the order in which they are received on a per-partition basis.
*/
mutex_lock(&vmbus_connection.channel_mutex);
/*
* Hyper-V will ignore MODIFYCHANNEL messages for "non-open" channels;
* avoid sending the message and fail here for such channels.
*/
if (channel->state != CHANNEL_OPENED_STATE) {
ret = -EIO;
goto cpu_store_unlock;
}
origin_cpu = channel->target_cpu;
if (target_cpu == origin_cpu)
goto cpu_store_unlock;
if (vmbus_send_modifychannel(channel->offermsg.child_relid,
hv_cpu_number_to_vp_number(target_cpu))) {
ret = -EIO;
goto cpu_store_unlock;
}
/*
* Warning. At this point, there is *no* guarantee that the host will
* have successfully processed the vmbus_send_modifychannel() request.
* See the header comment of vmbus_send_modifychannel() for more info.
*
* Lags in the processing of the above vmbus_send_modifychannel() can
* result in missed interrupts if the "old" target CPU is taken offline
* before Hyper-V starts sending interrupts to the "new" target CPU.
* But apart from this offlining scenario, the code tolerates such
* lags. It will function correctly even if a channel interrupt comes
* in on a CPU that is different from the channel target_cpu value.
*/
channel->target_cpu = target_cpu;
/* See init_vp_index(). */
if (hv_is_perf_channel(channel))
hv_update_alloced_cpus(origin_cpu, target_cpu);
/* Currently set only for storvsc channels. */
if (channel->change_target_cpu_callback) {
(*channel->change_target_cpu_callback)(channel,
origin_cpu, target_cpu);
}
cpu_store_unlock:
mutex_unlock(&vmbus_connection.channel_mutex);
cpus_read_unlock();
return ret;
}
static VMBUS_CHAN_ATTR(cpu, 0644, target_cpu_show, target_cpu_store);
static ssize_t channel_pending_show(struct vmbus_channel *channel,
char *buf)
{
return sprintf(buf, "%d\n",
channel_pending(channel,
vmbus_connection.monitor_pages[1]));
}
static VMBUS_CHAN_ATTR(pending, S_IRUGO, channel_pending_show, NULL);
static ssize_t channel_latency_show(struct vmbus_channel *channel,
char *buf)
{
return sprintf(buf, "%d\n",
channel_latency(channel,
vmbus_connection.monitor_pages[1]));
}
static VMBUS_CHAN_ATTR(latency, S_IRUGO, channel_latency_show, NULL);
static ssize_t channel_interrupts_show(struct vmbus_channel *channel, char *buf)
{
return sprintf(buf, "%llu\n", channel->interrupts);
}
static VMBUS_CHAN_ATTR(interrupts, S_IRUGO, channel_interrupts_show, NULL);
static ssize_t channel_events_show(struct vmbus_channel *channel, char *buf)
{
return sprintf(buf, "%llu\n", channel->sig_events);
}
static VMBUS_CHAN_ATTR(events, S_IRUGO, channel_events_show, NULL);
static ssize_t channel_intr_in_full_show(struct vmbus_channel *channel,
char *buf)
{
return sprintf(buf, "%llu\n",
(unsigned long long)channel->intr_in_full);
}
static VMBUS_CHAN_ATTR(intr_in_full, 0444, channel_intr_in_full_show, NULL);
static ssize_t channel_intr_out_empty_show(struct vmbus_channel *channel,
char *buf)
{
return sprintf(buf, "%llu\n",
(unsigned long long)channel->intr_out_empty);
}
static VMBUS_CHAN_ATTR(intr_out_empty, 0444, channel_intr_out_empty_show, NULL);
static ssize_t channel_out_full_first_show(struct vmbus_channel *channel,
char *buf)
{
return sprintf(buf, "%llu\n",
(unsigned long long)channel->out_full_first);
}
static VMBUS_CHAN_ATTR(out_full_first, 0444, channel_out_full_first_show, NULL);
static ssize_t channel_out_full_total_show(struct vmbus_channel *channel,
char *buf)
{
return sprintf(buf, "%llu\n",
(unsigned long long)channel->out_full_total);
}
static VMBUS_CHAN_ATTR(out_full_total, 0444, channel_out_full_total_show, NULL);
static ssize_t subchannel_monitor_id_show(struct vmbus_channel *channel,
char *buf)
{
return sprintf(buf, "%u\n", channel->offermsg.monitorid);
}
static VMBUS_CHAN_ATTR(monitor_id, S_IRUGO, subchannel_monitor_id_show, NULL);
static ssize_t subchannel_id_show(struct vmbus_channel *channel,
char *buf)
{
return sprintf(buf, "%u\n",
channel->offermsg.offer.sub_channel_index);
}
static VMBUS_CHAN_ATTR_RO(subchannel_id);
static struct attribute *vmbus_chan_attrs[] = {
&chan_attr_out_mask.attr,
&chan_attr_in_mask.attr,
&chan_attr_read_avail.attr,
&chan_attr_write_avail.attr,
&chan_attr_cpu.attr,
&chan_attr_pending.attr,
&chan_attr_latency.attr,
&chan_attr_interrupts.attr,
&chan_attr_events.attr,
&chan_attr_intr_in_full.attr,
&chan_attr_intr_out_empty.attr,
&chan_attr_out_full_first.attr,
&chan_attr_out_full_total.attr,
&chan_attr_monitor_id.attr,
&chan_attr_subchannel_id.attr,
NULL
};
/*
* Channel-level attribute_group callback function. Returns the permission for
* each attribute, and returns 0 if an attribute is not visible.
*/
static umode_t vmbus_chan_attr_is_visible(struct kobject *kobj,
struct attribute *attr, int idx)
{
const struct vmbus_channel *channel =
container_of(kobj, struct vmbus_channel, kobj);
/* Hide the monitor attributes if the monitor mechanism is not used. */
if (!channel->offermsg.monitor_allocated &&
(attr == &chan_attr_pending.attr ||
attr == &chan_attr_latency.attr ||
attr == &chan_attr_monitor_id.attr))
return 0;
return attr->mode;
}
static struct attribute_group vmbus_chan_group = {
.attrs = vmbus_chan_attrs,
.is_visible = vmbus_chan_attr_is_visible
};
static struct kobj_type vmbus_chan_ktype = {
.sysfs_ops = &vmbus_chan_sysfs_ops,
.release = vmbus_chan_release,
};
/*
* vmbus_add_channel_kobj - setup a sub-directory under device/channels
*/
int vmbus_add_channel_kobj(struct hv_device *dev, struct vmbus_channel *channel)
{
const struct device *device = &dev->device;
struct kobject *kobj = &channel->kobj;
u32 relid = channel->offermsg.child_relid;
int ret;
kobj->kset = dev->channels_kset;
ret = kobject_init_and_add(kobj, &vmbus_chan_ktype, NULL,
"%u", relid);
if (ret)
return ret;
ret = sysfs_create_group(kobj, &vmbus_chan_group);
if (ret) {
/*
* The calling functions' error handling paths will cleanup the
* empty channel directory.
*/
dev_err(device, "Unable to set up channel sysfs files\n");
return ret;
}
kobject_uevent(kobj, KOBJ_ADD);
return 0;
}
/*
* vmbus_remove_channel_attr_group - remove the channel's attribute group
*/
void vmbus_remove_channel_attr_group(struct vmbus_channel *channel)
{
sysfs_remove_group(&channel->kobj, &vmbus_chan_group);
}
/*
* vmbus_device_create - Creates and registers a new child device
* on the vmbus.
*/
struct hv_device *vmbus_device_create(const guid_t *type,
const guid_t *instance,
struct vmbus_channel *channel)
{
struct hv_device *child_device_obj;
child_device_obj = kzalloc(sizeof(struct hv_device), GFP_KERNEL);
if (!child_device_obj) {
pr_err("Unable to allocate device object for child device\n");
return NULL;
}
child_device_obj->channel = channel;
guid_copy(&child_device_obj->dev_type, type);
guid_copy(&child_device_obj->dev_instance, instance);
child_device_obj->vendor_id = 0x1414; /* MSFT vendor ID */
return child_device_obj;
}
/*
* vmbus_device_register - Register the child device
*/
int vmbus_device_register(struct hv_device *child_device_obj)
{
struct kobject *kobj = &child_device_obj->device.kobj;
int ret;
dev_set_name(&child_device_obj->device, "%pUl",
&child_device_obj->channel->offermsg.offer.if_instance);
child_device_obj->device.bus = &hv_bus;
child_device_obj->device.parent = &hv_acpi_dev->dev;
child_device_obj->device.release = vmbus_device_release;
/*
* Register with the LDM. This will kick off the driver/device
* binding...which will eventually call vmbus_match() and vmbus_probe()
*/
ret = device_register(&child_device_obj->device);
if (ret) {
pr_err("Unable to register child device\n");
return ret;
}
child_device_obj->channels_kset = kset_create_and_add("channels",
NULL, kobj);
if (!child_device_obj->channels_kset) {
ret = -ENOMEM;
goto err_dev_unregister;
}
ret = vmbus_add_channel_kobj(child_device_obj,
child_device_obj->channel);
if (ret) {
pr_err("Unable to register primary channeln");
goto err_kset_unregister;
}
hv_debug_add_dev_dir(child_device_obj);
return 0;
err_kset_unregister:
kset_unregister(child_device_obj->channels_kset);
err_dev_unregister:
device_unregister(&child_device_obj->device);
return ret;
}
/*
* vmbus_device_unregister - Remove the specified child device
* from the vmbus.
*/
void vmbus_device_unregister(struct hv_device *device_obj)
{
pr_debug("child device %s unregistered\n",
dev_name(&device_obj->device));
kset_unregister(device_obj->channels_kset);
/*
* Kick off the process of unregistering the device.
* This will call vmbus_remove() and eventually vmbus_device_release()
*/
device_unregister(&device_obj->device);
}
/*
* VMBUS is an acpi enumerated device. Get the information we
* need from DSDT.
*/
#define VTPM_BASE_ADDRESS 0xfed40000
static acpi_status vmbus_walk_resources(struct acpi_resource *res, void *ctx)
{
resource_size_t start = 0;
resource_size_t end = 0;
struct resource *new_res;
struct resource **old_res = &hyperv_mmio;
struct resource **prev_res = NULL;
struct resource r;
switch (res->type) {
/*
* "Address" descriptors are for bus windows. Ignore
* "memory" descriptors, which are for registers on
* devices.
*/
case ACPI_RESOURCE_TYPE_ADDRESS32:
start = res->data.address32.address.minimum;
end = res->data.address32.address.maximum;
break;
case ACPI_RESOURCE_TYPE_ADDRESS64:
start = res->data.address64.address.minimum;
end = res->data.address64.address.maximum;
break;
/*
* The IRQ information is needed only on ARM64, which Hyper-V
* sets up in the extended format. IRQ information is present
* on x86/x64 in the non-extended format but it is not used by
* Linux. So don't bother checking for the non-extended format.
*/
case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
if (!acpi_dev_resource_interrupt(res, 0, &r)) {
pr_err("Unable to parse Hyper-V ACPI interrupt\n");
return AE_ERROR;
}
/* ARM64 INTID for VMbus */
vmbus_interrupt = res->data.extended_irq.interrupts[0];
/* Linux IRQ number */
vmbus_irq = r.start;
return AE_OK;
default:
/* Unused resource type */
return AE_OK;
}
/*
* Ignore ranges that are below 1MB, as they're not
* necessary or useful here.
*/
if (end < 0x100000)
return AE_OK;
new_res = kzalloc(sizeof(*new_res), GFP_ATOMIC);
if (!new_res)
return AE_NO_MEMORY;
/* If this range overlaps the virtual TPM, truncate it. */
if (end > VTPM_BASE_ADDRESS && start < VTPM_BASE_ADDRESS)
end = VTPM_BASE_ADDRESS;
new_res->name = "hyperv mmio";
new_res->flags = IORESOURCE_MEM;
new_res->start = start;
new_res->end = end;
/*
* If two ranges are adjacent, merge them.
*/
do {
if (!*old_res) {
*old_res = new_res;
break;
}
if (((*old_res)->end + 1) == new_res->start) {
(*old_res)->end = new_res->end;
kfree(new_res);
break;
}
if ((*old_res)->start == new_res->end + 1) {
(*old_res)->start = new_res->start;
kfree(new_res);
break;
}
if ((*old_res)->start > new_res->end) {
new_res->sibling = *old_res;
if (prev_res)
(*prev_res)->sibling = new_res;
*old_res = new_res;
break;
}
prev_res = old_res;
old_res = &(*old_res)->sibling;
} while (1);
return AE_OK;
}
static int vmbus_acpi_remove(struct acpi_device *device)
{
struct resource *cur_res;
struct resource *next_res;
if (hyperv_mmio) {
if (fb_mmio) {
__release_region(hyperv_mmio, fb_mmio->start,
resource_size(fb_mmio));
fb_mmio = NULL;
}
for (cur_res = hyperv_mmio; cur_res; cur_res = next_res) {
next_res = cur_res->sibling;
kfree(cur_res);
}
}
return 0;
}
static void vmbus_reserve_fb(void)
{
int size;
/*
* Make a claim for the frame buffer in the resource tree under the
* first node, which will be the one below 4GB. The length seems to
* be underreported, particularly in a Generation 1 VM. So start out
* reserving a larger area and make it smaller until it succeeds.
*/
if (screen_info.lfb_base) {
if (efi_enabled(EFI_BOOT))
size = max_t(__u32, screen_info.lfb_size, 0x800000);
else
size = max_t(__u32, screen_info.lfb_size, 0x4000000);
for (; !fb_mmio && (size >= 0x100000); size >>= 1) {
fb_mmio = __request_region(hyperv_mmio,
screen_info.lfb_base, size,
fb_mmio_name, 0);
}
}
}
/**
* vmbus_allocate_mmio() - Pick a memory-mapped I/O range.
* @new: If successful, supplied a pointer to the
* allocated MMIO space.
* @device_obj: Identifies the caller
* @min: Minimum guest physical address of the
* allocation
* @max: Maximum guest physical address
* @size: Size of the range to be allocated
* @align: Alignment of the range to be allocated
* @fb_overlap_ok: Whether this allocation can be allowed
* to overlap the video frame buffer.
*
* This function walks the resources granted to VMBus by the
* _CRS object in the ACPI namespace underneath the parent
* "bridge" whether that's a root PCI bus in the Generation 1
* case or a Module Device in the Generation 2 case. It then
* attempts to allocate from the global MMIO pool in a way that
* matches the constraints supplied in these parameters and by
* that _CRS.
*
* Return: 0 on success, -errno on failure
*/
int vmbus_allocate_mmio(struct resource **new, struct hv_device *device_obj,
resource_size_t min, resource_size_t max,
resource_size_t size, resource_size_t align,
bool fb_overlap_ok)
{
struct resource *iter, *shadow;
resource_size_t range_min, range_max, start;
const char *dev_n = dev_name(&device_obj->device);
int retval;
retval = -ENXIO;
mutex_lock(&hyperv_mmio_lock);
/*
* If overlaps with frame buffers are allowed, then first attempt to
* make the allocation from within the reserved region. Because it
* is already reserved, no shadow allocation is necessary.
*/
if (fb_overlap_ok && fb_mmio && !(min > fb_mmio->end) &&
!(max < fb_mmio->start)) {
range_min = fb_mmio->start;
range_max = fb_mmio->end;
start = (range_min + align - 1) & ~(align - 1);
for (; start + size - 1 <= range_max; start += align) {
*new = request_mem_region_exclusive(start, size, dev_n);
if (*new) {
retval = 0;
goto exit;
}
}
}
for (iter = hyperv_mmio; iter; iter = iter->sibling) {
if ((iter->start >= max) || (iter->end <= min))
continue;
range_min = iter->start;
range_max = iter->end;
start = (range_min + align - 1) & ~(align - 1);
for (; start + size - 1 <= range_max; start += align) {
shadow = __request_region(iter, start, size, NULL,
IORESOURCE_BUSY);
if (!shadow)
continue;
*new = request_mem_region_exclusive(start, size, dev_n);
if (*new) {
shadow->name = (char *)*new;
retval = 0;
goto exit;
}
__release_region(iter, start, size);
}
}
exit:
mutex_unlock(&hyperv_mmio_lock);
return retval;
}
EXPORT_SYMBOL_GPL(vmbus_allocate_mmio);
/**
* vmbus_free_mmio() - Free a memory-mapped I/O range.
* @start: Base address of region to release.
* @size: Size of the range to be allocated
*
* This function releases anything requested by
* vmbus_mmio_allocate().
*/
void vmbus_free_mmio(resource_size_t start, resource_size_t size)
{
struct resource *iter;
mutex_lock(&hyperv_mmio_lock);
for (iter = hyperv_mmio; iter; iter = iter->sibling) {
if ((iter->start >= start + size) || (iter->end <= start))
continue;
__release_region(iter, start, size);
}
release_mem_region(start, size);
mutex_unlock(&hyperv_mmio_lock);
}
EXPORT_SYMBOL_GPL(vmbus_free_mmio);
static int vmbus_acpi_add(struct acpi_device *device)
{
acpi_status result;
int ret_val = -ENODEV;
struct acpi_device *ancestor;
hv_acpi_dev = device;
result = acpi_walk_resources(device->handle, METHOD_NAME__CRS,
vmbus_walk_resources, NULL);
if (ACPI_FAILURE(result))
goto acpi_walk_err;
/*
* Some ancestor of the vmbus acpi device (Gen1 or Gen2
* firmware) is the VMOD that has the mmio ranges. Get that.
*/
for (ancestor = device->parent; ancestor; ancestor = ancestor->parent) {
result = acpi_walk_resources(ancestor->handle, METHOD_NAME__CRS,
vmbus_walk_resources, NULL);
if (ACPI_FAILURE(result))
continue;
if (hyperv_mmio) {
vmbus_reserve_fb();
break;
}
}
ret_val = 0;
acpi_walk_err:
complete(&probe_event);
if (ret_val)
vmbus_acpi_remove(device);
return ret_val;
}
#ifdef CONFIG_PM_SLEEP
static int vmbus_bus_suspend(struct device *dev)
{
struct vmbus_channel *channel, *sc;
while (atomic_read(&vmbus_connection.offer_in_progress) != 0) {
/*
* We wait here until the completion of any channel
* offers that are currently in progress.
*/
msleep(1);
}
mutex_lock(&vmbus_connection.channel_mutex);
list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) {
if (!is_hvsock_channel(channel))
continue;
vmbus_force_channel_rescinded(channel);
}
mutex_unlock(&vmbus_connection.channel_mutex);
/*
* Wait until all the sub-channels and hv_sock channels have been
* cleaned up. Sub-channels should be destroyed upon suspend, otherwise
* they would conflict with the new sub-channels that will be created
* in the resume path. hv_sock channels should also be destroyed, but
* a hv_sock channel of an established hv_sock connection can not be
* really destroyed since it may still be referenced by the userspace
* application, so we just force the hv_sock channel to be rescinded
* by vmbus_force_channel_rescinded(), and the userspace application
* will thoroughly destroy the channel after hibernation.
*
* Note: the counter nr_chan_close_on_suspend may never go above 0 if
* the VM has no sub-channel and hv_sock channel, e.g. a 1-vCPU VM.
*/
if (atomic_read(&vmbus_connection.nr_chan_close_on_suspend) > 0)
wait_for_completion(&vmbus_connection.ready_for_suspend_event);
WARN_ON(atomic_read(&vmbus_connection.nr_chan_fixup_on_resume) != 0);
mutex_lock(&vmbus_connection.channel_mutex);
list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) {
/*
* Remove the channel from the array of channels and invalidate
* the channel's relid. Upon resume, vmbus_onoffer() will fix
* up the relid (and other fields, if necessary) and add the
* channel back to the array.
*/
vmbus_channel_unmap_relid(channel);
channel->offermsg.child_relid = INVALID_RELID;
if (is_hvsock_channel(channel)) {
if (!channel->rescind) {
pr_err("hv_sock channel not rescinded!\n");
WARN_ON_ONCE(1);
}
continue;
}
list_for_each_entry(sc, &channel->sc_list, sc_list) {
pr_err("Sub-channel not deleted!\n");
WARN_ON_ONCE(1);
}
atomic_inc(&vmbus_connection.nr_chan_fixup_on_resume);
}
mutex_unlock(&vmbus_connection.channel_mutex);
vmbus_initiate_unload(false);
/* Reset the event for the next resume. */
reinit_completion(&vmbus_connection.ready_for_resume_event);
return 0;
}
static int vmbus_bus_resume(struct device *dev)
{
struct vmbus_channel_msginfo *msginfo;
size_t msgsize;
int ret;
/*
* We only use the 'vmbus_proto_version', which was in use before
* hibernation, to re-negotiate with the host.
*/
if (!vmbus_proto_version) {
pr_err("Invalid proto version = 0x%x\n", vmbus_proto_version);
return -EINVAL;
}
msgsize = sizeof(*msginfo) +
sizeof(struct vmbus_channel_initiate_contact);
msginfo = kzalloc(msgsize, GFP_KERNEL);
if (msginfo == NULL)
return -ENOMEM;
ret = vmbus_negotiate_version(msginfo, vmbus_proto_version);
kfree(msginfo);
if (ret != 0)
return ret;
WARN_ON(atomic_read(&vmbus_connection.nr_chan_fixup_on_resume) == 0);
vmbus_request_offers();
wait_for_completion(&vmbus_connection.ready_for_resume_event);
/* Reset the event for the next suspend. */
reinit_completion(&vmbus_connection.ready_for_suspend_event);
return 0;
}
#else
#define vmbus_bus_suspend NULL
#define vmbus_bus_resume NULL
#endif /* CONFIG_PM_SLEEP */
static const struct acpi_device_id vmbus_acpi_device_ids[] = {
{"VMBUS", 0},
{"VMBus", 0},
{"", 0},
};
MODULE_DEVICE_TABLE(acpi, vmbus_acpi_device_ids);
/*
* Note: we must use the "no_irq" ops, otherwise hibernation can not work with
* PCI device assignment, because "pci_dev_pm_ops" uses the "noirq" ops: in
* the resume path, the pci "noirq" restore op runs before "non-noirq" op (see
* resume_target_kernel() -> dpm_resume_start(), and hibernation_restore() ->
* dpm_resume_end()). This means vmbus_bus_resume() and the pci-hyperv's
* resume callback must also run via the "noirq" ops.
*
* Set suspend_noirq/resume_noirq to NULL for Suspend-to-Idle: see the comment
* earlier in this file before vmbus_pm.
*/
static const struct dev_pm_ops vmbus_bus_pm = {
.suspend_noirq = NULL,
.resume_noirq = NULL,
.freeze_noirq = vmbus_bus_suspend,
.thaw_noirq = vmbus_bus_resume,
.poweroff_noirq = vmbus_bus_suspend,
.restore_noirq = vmbus_bus_resume
};
static struct acpi_driver vmbus_acpi_driver = {
.name = "vmbus",
.ids = vmbus_acpi_device_ids,
.ops = {
.add = vmbus_acpi_add,
.remove = vmbus_acpi_remove,
},
.drv.pm = &vmbus_bus_pm,
};
static void hv_kexec_handler(void)
{
hv_stimer_global_cleanup();
vmbus_initiate_unload(false);
/* Make sure conn_state is set as hv_synic_cleanup checks for it */
mb();
cpuhp_remove_state(hyperv_cpuhp_online);
hyperv_cleanup();
};
static void hv_crash_handler(struct pt_regs *regs)
{
int cpu;
vmbus_initiate_unload(true);
/*
* In crash handler we can't schedule synic cleanup for all CPUs,
* doing the cleanup for current CPU only. This should be sufficient
* for kdump.
*/
cpu = smp_processor_id();
hv_stimer_cleanup(cpu);
hv_synic_disable_regs(cpu);
hyperv_cleanup();
};
static int hv_synic_suspend(void)
{
/*
* When we reach here, all the non-boot CPUs have been offlined.
* If we're in a legacy configuration where stimer Direct Mode is
* not enabled, the stimers on the non-boot CPUs have been unbound
* in hv_synic_cleanup() -> hv_stimer_legacy_cleanup() ->
* hv_stimer_cleanup() -> clockevents_unbind_device().
*
* hv_synic_suspend() only runs on CPU0 with interrupts disabled.
* Here we do not call hv_stimer_legacy_cleanup() on CPU0 because:
* 1) it's unnecessary as interrupts remain disabled between
* syscore_suspend() and syscore_resume(): see create_image() and
* resume_target_kernel()
* 2) the stimer on CPU0 is automatically disabled later by
* syscore_suspend() -> timekeeping_suspend() -> tick_suspend() -> ...
* -> clockevents_shutdown() -> ... -> hv_ce_shutdown()
* 3) a warning would be triggered if we call
* clockevents_unbind_device(), which may sleep, in an
* interrupts-disabled context.
*/
hv_synic_disable_regs(0);
return 0;
}
static void hv_synic_resume(void)
{
hv_synic_enable_regs(0);
/*
* Note: we don't need to call hv_stimer_init(0), because the timer
* on CPU0 is not unbound in hv_synic_suspend(), and the timer is
* automatically re-enabled in timekeeping_resume().
*/
}
/* The callbacks run only on CPU0, with irqs_disabled. */
static struct syscore_ops hv_synic_syscore_ops = {
.suspend = hv_synic_suspend,
.resume = hv_synic_resume,
};
static int __init hv_acpi_init(void)
{
int ret, t;
if (!hv_is_hyperv_initialized())
return -ENODEV;
init_completion(&probe_event);
/*
* Get ACPI resources first.
*/
ret = acpi_bus_register_driver(&vmbus_acpi_driver);
if (ret)
return ret;
t = wait_for_completion_timeout(&probe_event, 5*HZ);
if (t == 0) {
ret = -ETIMEDOUT;
goto cleanup;
}
hv_debug_init();
ret = vmbus_bus_init();
if (ret)
goto cleanup;
hv_setup_kexec_handler(hv_kexec_handler);
hv_setup_crash_handler(hv_crash_handler);
register_syscore_ops(&hv_synic_syscore_ops);
return 0;
cleanup:
acpi_bus_unregister_driver(&vmbus_acpi_driver);
hv_acpi_dev = NULL;
return ret;
}
static void __exit vmbus_exit(void)
{
int cpu;
unregister_syscore_ops(&hv_synic_syscore_ops);
hv_remove_kexec_handler();
hv_remove_crash_handler();
vmbus_connection.conn_state = DISCONNECTED;
hv_stimer_global_cleanup();
vmbus_disconnect();
hv_remove_vmbus_irq();
for_each_online_cpu(cpu) {
struct hv_per_cpu_context *hv_cpu
= per_cpu_ptr(hv_context.cpu_context, cpu);
tasklet_kill(&hv_cpu->msg_dpc);
}
hv_debug_rm_all_dir();
vmbus_free_channels();
kfree(vmbus_connection.channels);
if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE) {
kmsg_dump_unregister(&hv_kmsg_dumper);
unregister_die_notifier(&hyperv_die_block);
atomic_notifier_chain_unregister(&panic_notifier_list,
&hyperv_panic_block);
}
free_page((unsigned long)hv_panic_page);
unregister_sysctl_table(hv_ctl_table_hdr);
hv_ctl_table_hdr = NULL;
bus_unregister(&hv_bus);
cpuhp_remove_state(hyperv_cpuhp_online);
hv_synic_free();
acpi_bus_unregister_driver(&vmbus_acpi_driver);
}
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Microsoft Hyper-V VMBus Driver");
subsys_initcall(hv_acpi_init);
module_exit(vmbus_exit);
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