netdevsim: move device registration and related code to bus.c

Move netdevsim device registration into bus.c and alongside with that
the related sysfs attributes. Introduce new struct nsim_bus_dev to
represent a netdevsim device on netdevsim bus.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/netdevsim/bus.c

@@ -4,15 +4,155 @@
  */
 
 #include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/rtnetlink.h>
+#include <linux/slab.h>
+#include <linux/sysfs.h>
 
 #include "netdevsim.h"
 
-struct bus_type nsim_bus = {
+static u32 nsim_bus_dev_id;
+
+static struct nsim_bus_dev *to_nsim_bus_dev(struct device *dev)
+{
+	return container_of(dev, struct nsim_bus_dev, dev);
+}
+
+static int nsim_bus_dev_vfs_enable(struct nsim_bus_dev *nsim_bus_dev,
+				   unsigned int num_vfs)
+{
+	nsim_bus_dev->vfconfigs = kcalloc(num_vfs,
+					  sizeof(struct nsim_vf_config),
+					  GFP_KERNEL);
+	if (!nsim_bus_dev->vfconfigs)
+		return -ENOMEM;
+	nsim_bus_dev->num_vfs = num_vfs;
+
+	return 0;
+}
+
+static void nsim_bus_dev_vfs_disable(struct nsim_bus_dev *nsim_bus_dev)
+{
+	kfree(nsim_bus_dev->vfconfigs);
+	nsim_bus_dev->vfconfigs = NULL;
+	nsim_bus_dev->num_vfs = 0;
+}
+
+static ssize_t
+nsim_bus_dev_numvfs_store(struct device *dev, struct device_attribute *attr,
+			  const char *buf, size_t count)
+{
+	struct nsim_bus_dev *nsim_bus_dev = to_nsim_bus_dev(dev);
+	unsigned int num_vfs;
+	int ret;
+
+	ret = kstrtouint(buf, 0, &num_vfs);
+	if (ret)
+		return ret;
+
+	rtnl_lock();
+	if (nsim_bus_dev->num_vfs == num_vfs)
+		goto exit_good;
+	if (nsim_bus_dev->num_vfs && num_vfs) {
+		ret = -EBUSY;
+		goto exit_unlock;
+	}
+
+	if (num_vfs) {
+		ret = nsim_bus_dev_vfs_enable(nsim_bus_dev, num_vfs);
+		if (ret)
+			goto exit_unlock;
+	} else {
+		nsim_bus_dev_vfs_disable(nsim_bus_dev);
+	}
+exit_good:
+	ret = count;
+exit_unlock:
+	rtnl_unlock();
+
+	return ret;
+}
+
+static ssize_t
+nsim_bus_dev_numvfs_show(struct device *dev,
+			 struct device_attribute *attr, char *buf)
+{
+	struct nsim_bus_dev *nsim_bus_dev = to_nsim_bus_dev(dev);
+
+	return sprintf(buf, "%u\n", nsim_bus_dev->num_vfs);
+}
+
+static struct device_attribute nsim_bus_dev_numvfs_attr =
+	__ATTR(sriov_numvfs, 0664, nsim_bus_dev_numvfs_show,
+	       nsim_bus_dev_numvfs_store);
+
+static struct attribute *nsim_bus_dev_attrs[] = {
+	&nsim_bus_dev_numvfs_attr.attr,
+	NULL,
+};
+
+static const struct attribute_group nsim_bus_dev_attr_group = {
+	.attrs = nsim_bus_dev_attrs,
+};
+
+static const struct attribute_group *nsim_bus_dev_attr_groups[] = {
+	&nsim_bus_dev_attr_group,
+	NULL,
+};
+
+static void nsim_bus_dev_release(struct device *dev)
+{
+	struct nsim_bus_dev *nsim_bus_dev = to_nsim_bus_dev(dev);
+
+	nsim_bus_dev_vfs_disable(nsim_bus_dev);
+}
+
+static struct device_type nsim_bus_dev_type = {
+	.groups = nsim_bus_dev_attr_groups,
+	.release = nsim_bus_dev_release,
+};
+
+int nsim_num_vf(struct device *dev)
+{
+	struct nsim_bus_dev *nsim_bus_dev = to_nsim_bus_dev(dev);
+
+	return nsim_bus_dev->num_vfs;
+}
+
+static struct bus_type nsim_bus = {
 	.name		= DRV_NAME,
 	.dev_name	= DRV_NAME,
 	.num_vf		= nsim_num_vf,
 };
 
+struct nsim_bus_dev *nsim_bus_dev_new(void)
+{
+	struct nsim_bus_dev *nsim_bus_dev;
+	int err;
+
+	nsim_bus_dev = kzalloc(sizeof(*nsim_bus_dev), GFP_KERNEL);
+	if (!nsim_bus_dev)
+		return ERR_PTR(-ENOMEM);
+
+	nsim_bus_dev->dev.id = nsim_bus_dev_id++;
+	nsim_bus_dev->dev.bus = &nsim_bus;
+	nsim_bus_dev->dev.type = &nsim_bus_dev_type;
+	err = device_register(&nsim_bus_dev->dev);
+	if (err)
+		goto err_nsim_bus_dev_free;
+	return nsim_bus_dev;
+
+err_nsim_bus_dev_free:
+	kfree(nsim_bus_dev);
+	return ERR_PTR(err);
+}
+
+void nsim_bus_dev_del(struct nsim_bus_dev *nsim_bus_dev)
+{
+	device_unregister(&nsim_bus_dev->dev);
+	kfree(nsim_bus_dev);
+}
+
 int nsim_bus_init(void)
 {
 	return bus_register(&nsim_bus);

drivers/net/netdevsim/dev.c

@@ -199,7 +199,7 @@ static int __nsim_dev_init(struct netdevsim *ns)
 	if (err)
 		goto err_fib_destroy;
 
-	err = devlink_register(devlink, &ns->dev);
+	err = devlink_register(devlink, &ns->nsim_bus_dev->dev);
 	if (err)
 		goto err_resources_unregister;