IB/core: Allow device-specific per-port sysfs files

Add a new parameter to ib_register_device() so that low-level device
drivers can pass in a pointer to a callback function that will be
called for each port that is registered in sysfs.  This allows
low-level device drivers to create files in

    /sys/class/infiniband/<hca>/ports/<N>/

without having to poke through the internals of the RDMA sysfs handling.

There is no need for an unregister function since the kobject
reference will go to zero when ib_unregister_device() is called.

Signed-off-by: Ralph Campbell <ralph.campbell@qlogic.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

3 files changed, 24 insertions, 7 deletions

diff --git a/drivers/infiniband/core/core_priv.h b/drivers/infiniband/core/core_priv.h
index 05ac36e..a565af5 100644
--- a/drivers/infiniband/core/core_priv.h
+++ b/drivers/infiniband/core/core_priv.h
@@ -38,7 +38,9 @@
 
 #include <rdma/ib_verbs.h>
 
-int  ib_device_register_sysfs(struct ib_device *device);
+int  ib_device_register_sysfs(struct ib_device *device,
+			      int (*port_callback)(struct ib_device *,
+						   u8, struct kobject *));
 void ib_device_unregister_sysfs(struct ib_device *device);
 
 int  ib_sysfs_setup(void);
diff --git a/drivers/infiniband/core/device.c b/drivers/infiniband/core/device.c
index d1fba41..a19effa 100644
--- a/drivers/infiniband/core/device.c
+++ b/drivers/infiniband/core/device.c
@@ -267,7 +267,9 @@ out:
  * callback for each device that is added. @device must be allocated
  * with ib_alloc_device().
  */
-int ib_register_device(struct ib_device *device)
+int ib_register_device(struct ib_device *device,
+		       int (*port_callback)(struct ib_device *,
+					    u8, struct kobject *))
 {
 	int ret;
 
@@ -296,7 +298,7 @@ int ib_register_device(struct ib_device *device)
 		goto out;
 	}
 
-	ret = ib_device_register_sysfs(device);
+	ret = ib_device_register_sysfs(device, port_callback);
 	if (ret) {
 		printk(KERN_WARNING "Couldn't register device %s with driver model\n",
 		       device->name);
diff --git a/drivers/infiniband/core/sysfs.c b/drivers/infiniband/core/sysfs.c
index f901957..3627300 100644
--- a/drivers/infiniband/core/sysfs.c
+++ b/drivers/infiniband/core/sysfs.c
@@ -475,7 +475,9 @@ err:
 	return NULL;
 }
 
-static int add_port(struct ib_device *device, int port_num)
+static int add_port(struct ib_device *device, int port_num,
+		    int (*port_callback)(struct ib_device *,
+					 u8, struct kobject *))
 {
 	struct ib_port *p;
 	struct ib_port_attr attr;
@@ -522,11 +524,20 @@ static int add_port(struct ib_device *device, int port_num)
 	if (ret)
 		goto err_free_pkey;
 
+	if (port_callback) {
+		ret = port_callback(device, port_num, &p->kobj);
+		if (ret)
+			goto err_remove_pkey;
+	}
+
 	list_add_tail(&p->kobj.entry, &device->port_list);
 
 	kobject_uevent(&p->kobj, KOBJ_ADD);
 	return 0;
 
+err_remove_pkey:
+	sysfs_remove_group(&p->kobj, &p->pkey_group);
+
 err_free_pkey:
 	for (i = 0; i < attr.pkey_tbl_len; ++i)
 		kfree(p->pkey_group.attrs[i]);
@@ -754,7 +765,9 @@ static struct attribute_group iw_stats_group = {
 	.attrs	= iw_proto_stats_attrs,
 };
 
-int ib_device_register_sysfs(struct ib_device *device)
+int ib_device_register_sysfs(struct ib_device *device,
+			     int (*port_callback)(struct ib_device *,
+						  u8, struct kobject *))
 {
 	struct device *class_dev = &device->dev;
 	int ret;
@@ -785,12 +798,12 @@ int ib_device_register_sysfs(struct ib_device *device)
 	}
 
 	if (device->node_type == RDMA_NODE_IB_SWITCH) {
-		ret = add_port(device, 0);
+		ret = add_port(device, 0, port_callback);
 		if (ret)
 			goto err_put;
 	} else {
 		for (i = 1; i <= device->phys_port_cnt; ++i) {
-			ret = add_port(device, i);
+			ret = add_port(device, i, port_callback);
 			if (ret)
 				goto err_put;
 		}