It's a number based on the vmbus device offer sequence.
Useful for device naming when using Async probing.
Signed-off-by: Haiyang Zhang <haiyangz@xxxxxxxxxxxxx>
---
Documentation/ABI/stable/sysfs-bus-vmbus | 8 ++++++++
drivers/hv/vmbus_drv.c | 13 +++++++++++++
2 files changed, 21 insertions(+)
diff --git a/Documentation/ABI/stable/sysfs-bus-vmbus b/Documentation/ABI/stable/sysfs-bus-vmbus
index 8e8d167..a42225d 100644
--- a/Documentation/ABI/stable/sysfs-bus-vmbus
+++ b/Documentation/ABI/stable/sysfs-bus-vmbus
@@ -49,6 +49,14 @@ Contact: Stephen Hemminger <sthemmin@xxxxxxxxxxxxx>
Description: This NUMA node to which the VMBUS device is
attached, or -1 if the node is unknown.
+What: /sys/bus/vmbus/devices/<UUID>/dev_num
+Date: Dec 2019
+KernelVersion: 5.5
+Contact: Haiyang Zhang <haiyangz@xxxxxxxxxxxxx>
+Description: A number based on the vmbus device offer sequence.
+ Useful for device naming when using Async probing.
+Users: Debugging tools and userspace drivers
+
What: /sys/bus/vmbus/devices/<UUID>/channels/<N>
Date: September. 2017
KernelVersion: 4.14
diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
index 4ef5a66..fe7aefa 100644
--- a/drivers/hv/vmbus_drv.c
+++ b/drivers/hv/vmbus_drv.c
@@ -214,6 +214,18 @@ static ssize_t numa_node_show(struct device *dev,
static DEVICE_ATTR_RO(numa_node);
#endif
+static ssize_t dev_num_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", hv_dev->channel->dev_num);
+}
+static DEVICE_ATTR_RO(dev_num);
+
static ssize_t server_monitor_pending_show(struct device *dev,
struct device_attribute *dev_attr,
char *buf)
@@ -598,6 +610,7 @@ static ssize_t driver_override_show(struct device *dev,
#ifdef CONFIG_NUMA
&dev_attr_numa_node.attr,
#endif
+ &dev_attr_dev_num.attr,
&dev_attr_server_monitor_pending.attr,
&dev_attr_client_monitor_pending.attr,
&dev_attr_server_monitor_latency.attr,
--
1.8.3.1
