[patch net-next v4 08/16] netdevsim: add bus attributes to add new and delete devices

Jiri Pirko
2019-04-25T14:00:12Z

Add a way to add new netdevsim device on netdevsim bus and also to
delete existing netdevsim device from the bus. Track the bus devices
in using a list.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
---
v3->v4:
- fix wrapping of function declararions according to Jakub's rules.
---
drivers/net/netdevsim/bus.c | 97 ++++++++++++++++++++++++++++++-
drivers/net/netdevsim/netdev.c | 2 +-
drivers/net/netdevsim/netdevsim.h | 4 +-
3 files changed, 99 insertions(+), 4 deletions(-)

diff --git a/drivers/net/netdevsim/bus.c b/drivers/net/netdevsim/bus.c
index c50c5ea90555..c30692f17374 100644
--- a/drivers/net/netdevsim/bus.c
+++ b/drivers/net/netdevsim/bus.c
@@ -6,6 +6,8 @@
#include <linux/device.h>
#include <linux/idr.h>
#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/mutex.h>
#include <linux/rtnetlink.h>
#include <linux/slab.h>
#include <linux/sysfs.h>
@@ -13,6 +15,8 @@
#include "netdevsim.h"

static DEFINE_IDA(nsim_bus_dev_ids);
+static LIST_HEAD(nsim_bus_dev_list);
+static DEFINE_MUTEX(nsim_bus_dev_list_lock);

static struct nsim_bus_dev *to_nsim_bus_dev(struct device *dev)
{
@@ -113,6 +117,83 @@ static struct device_type nsim_bus_dev_type = {
.release = nsim_bus_dev_release,
};

+static ssize_t
+new_device_store(struct bus_type *bus, const char *buf, size_t count)
+{
+ struct nsim_bus_dev *nsim_bus_dev;
+ unsigned int port_count;
+ unsigned int id;
+ int err;
+
+ err = sscanf(buf, "%u %u", &id, &port_count);
+ switch (err) {
+ case 1:
+ port_count = 1;
+ /* pass through */
+ case 2:
+ if (id > INT_MAX) {
+ pr_err("Value of \"id\" is too big.\n");
+ return -EINVAL;
+ }
+ break;
+ default:
+ pr_err("Format for adding new device is \"id port_count\" (uint uint).\n");
+ return -EINVAL;
+ }
+ nsim_bus_dev = nsim_bus_dev_new(id, port_count);
+ if (IS_ERR(nsim_bus_dev))
+ return PTR_ERR(nsim_bus_dev);
+
+ mutex_lock(&nsim_bus_dev_list_lock);
+ list_add_tail(&nsim_bus_dev->list, &nsim_bus_dev_list);
+ mutex_unlock(&nsim_bus_dev_list_lock);
+
+ return count;
+}
+static BUS_ATTR_WO(new_device);
+
+static ssize_t
+del_device_store(struct bus_type *bus, const char *buf, size_t count)
+{
+ struct nsim_bus_dev *nsim_bus_dev, *tmp;
+ unsigned int id;
+ int err;
+
+ err = sscanf(buf, "%u", &id);
+ switch (err) {
+ case 1:
+ if (id > INT_MAX) {
+ pr_err("Value of \"id\" is too big.\n");
+ return -EINVAL;
+ }
+ break;
+ default:
+ pr_err("Format for deleting device is \"id\" (uint).\n");
+ return -EINVAL;
+ }
+
+ err = -ENOENT;
+ mutex_lock(&nsim_bus_dev_list_lock);
+ list_for_each_entry_safe(nsim_bus_dev, tmp, &nsim_bus_dev_list, list) {
+ if (nsim_bus_dev->dev.id != id)
+ continue;
+ list_del(&nsim_bus_dev->list);
+ nsim_bus_dev_del(nsim_bus_dev);
+ err = 0;
+ break;
+ }
+ mutex_unlock(&nsim_bus_dev_list_lock);
+ return !err ? count : err;
+}
+static BUS_ATTR_WO(del_device);
+
+static struct attribute *nsim_bus_attrs[] = {
+ &bus_attr_new_device.attr,
+ &bus_attr_del_device.attr,
+ NULL
+};
+ATTRIBUTE_GROUPS(nsim_bus);
+
int nsim_num_vf(struct device *dev)
{
struct nsim_bus_dev *nsim_bus_dev = to_nsim_bus_dev(dev);
@@ -123,10 +204,11 @@ int nsim_num_vf(struct device *dev)
static struct bus_type nsim_bus = {
.name = DRV_NAME,
.dev_name = DRV_NAME,
+ .bus_groups = nsim_bus_groups,
.num_vf = nsim_num_vf,
};

-struct nsim_bus_dev *nsim_bus_dev_new(void)
+struct nsim_bus_dev *nsim_bus_dev_new(unsigned int id, unsigned int port_count)
{
struct nsim_bus_dev *nsim_bus_dev;
int err;
@@ -135,12 +217,15 @@ struct nsim_bus_dev *nsim_bus_dev_new(void)
if (!nsim_bus_dev)
return ERR_PTR(-ENOMEM);

- err = ida_alloc(&nsim_bus_dev_ids, GFP_KERNEL);
+ err = ida_alloc_range(&nsim_bus_dev_ids,
+ id == ~0 ? 0 : id, id, GFP_KERNEL);
if (err < 0)
goto err_nsim_bus_dev_free;
nsim_bus_dev->dev.id = err;
nsim_bus_dev->dev.bus = &nsim_bus;
nsim_bus_dev->dev.type = &nsim_bus_dev_type;
+ nsim_bus_dev->port_count = port_count;
+
err = device_register(&nsim_bus_dev->dev);
if (err)
goto err_nsim_bus_dev_id_free;
@@ -185,6 +270,14 @@ int nsim_bus_init(void)

void nsim_bus_exit(void)
{
+ struct nsim_bus_dev *nsim_bus_dev, *tmp;
+
+ mutex_lock(&nsim_bus_dev_list_lock);
+ list_for_each_entry_safe(nsim_bus_dev, tmp, &nsim_bus_dev_list, list) {
+ list_del(&nsim_bus_dev->list);
+ nsim_bus_dev_del(nsim_bus_dev);
+ }
+ mutex_unlock(&nsim_bus_dev_list_lock);
driver_unregister(&nsim_driver);
bus_unregister(&nsim_bus);
}
diff --git a/drivers/net/netdevsim/netdev.c b/drivers/net/netdevsim/netdev.c
index 3407b009929e..37a442ffcb8b 100644
--- a/drivers/net/netdevsim/netdev.c
+++ b/drivers/net/netdevsim/netdev.c
@@ -386,7 +386,7 @@ static int nsim_newlink(struct net *src_net, struct net_device *dev,
if (IS_ERR(ns->sdev))
return PTR_ERR(ns->sdev);

- ns->nsim_bus_dev = nsim_bus_dev_new();
+ ns->nsim_bus_dev = nsim_bus_dev_new(~0, 0);
if (IS_ERR(ns->nsim_bus_dev)) {
err = PTR_ERR(ns->nsim_bus_dev);
goto err_sdev_put;
diff --git a/drivers/net/netdevsim/netdevsim.h b/drivers/net/netdevsim/netdevsim.h
index 528d1e7d3e6b..8d61fcb55f39 100644
--- a/drivers/net/netdevsim/netdevsim.h
+++ b/drivers/net/netdevsim/netdevsim.h
@@ -196,11 +196,13 @@ struct nsim_vf_config {

struct nsim_bus_dev {
struct device dev;
+ struct list_head list;
+ unsigned int port_count;
unsigned int num_vfs;
struct nsim_vf_config *vfconfigs;
};

-struct nsim_bus_dev *nsim_bus_dev_new(void);
+struct nsim_bus_dev *nsim_bus_dev_new(unsigned int id, unsigned int port_count);
void nsim_bus_dev_del(struct nsim_bus_dev *nsim_bus_dev);
int nsim_bus_init(void);
void nsim_bus_exit(void);
--
2.17.2