2022-03-30 11:56:29

by Corey Minyard

[permalink] [raw]
Subject: [PATCH 4/4] ipmi: Add a sysfs count of total outstanding messages for an interface

From: Corey Minyard <[email protected]>

Go through each user and add its message count to a total and print the
total.

It would be nice to have a per-user file, but there's no user sysfs
entity at this point to hang it off of. Probably not worth the effort.

Based on work by Chen Guanqiao <[email protected]>

Cc: Chen Guanqiao <[email protected]>
Signed-off-by: Corey Minyard <[email protected]>
---
drivers/char/ipmi/ipmi_msghandler.c | 29 +++++++++++++++++++++++++++++
1 file changed, 29 insertions(+)

diff --git a/drivers/char/ipmi/ipmi_msghandler.c b/drivers/char/ipmi/ipmi_msghandler.c
index 3ba188e05ca6..e30223763a2a 100644
--- a/drivers/char/ipmi/ipmi_msghandler.c
+++ b/drivers/char/ipmi/ipmi_msghandler.c
@@ -458,6 +458,7 @@ struct ipmi_smi {
struct srcu_struct users_srcu;
atomic_t nr_users;
struct device_attribute nr_users_devattr;
+ struct device_attribute nr_msgs_devattr;


/* Used for wake ups at startup. */
@@ -3519,6 +3520,25 @@ static ssize_t nr_users_show(struct device *dev,
}
static DEVICE_ATTR_RO(nr_users);

+static ssize_t nr_msgs_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct ipmi_smi *intf = container_of(attr,
+ struct ipmi_smi, nr_msgs_devattr);
+ struct ipmi_user *user;
+ int index;
+ unsigned int count = 0;
+
+ index = srcu_read_lock(&intf->users_srcu);
+ list_for_each_entry_rcu(user, &intf->users, link)
+ count += atomic_read(&user->nr_msgs);
+ srcu_read_unlock(&intf->users_srcu, index);
+
+ return sysfs_emit(buf, "%u\n", count);
+}
+static DEVICE_ATTR_RO(nr_msgs);
+
static void redo_bmc_reg(struct work_struct *work)
{
struct ipmi_smi *intf = container_of(work, struct ipmi_smi,
@@ -3647,6 +3667,14 @@ int ipmi_add_smi(struct module *owner,
if (rv)
goto out_err_bmc_reg;

+ intf->nr_msgs_devattr = dev_attr_nr_msgs;
+ sysfs_attr_init(&intf->nr_msgs_devattr.attr);
+ rv = device_create_file(intf->si_dev, &intf->nr_msgs_devattr);
+ if (rv) {
+ device_remove_file(intf->si_dev, &intf->nr_users_devattr);
+ goto out_err_bmc_reg;
+ }
+
/*
* Keep memory order straight for RCU readers. Make
* sure everything else is committed to memory before
@@ -3743,6 +3771,7 @@ void ipmi_unregister_smi(struct ipmi_smi *intf)

/* At this point no users can be added to the interface. */

+ device_remove_file(intf->si_dev, &intf->nr_msgs_devattr);
device_remove_file(intf->si_dev, &intf->nr_users_devattr);

/*
--
2.25.1