[PATCH] iseries_veth: Add sysfs support for connection structs

To aid in field debugging, add sysfs support for iseries_veth's connection
structures. At the moment this is all read-only, however we could think about
adding write support for some attributes in future.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>

1 files changed, 90 insertions, 4 deletions

diff --git a/drivers/net/iseries_veth.c b/drivers/net/iseries_veth.c
index b945bf02d257..25481ea67474 100644
--- a/drivers/net/iseries_veth.c
+++ b/drivers/net/iseries_veth.c
@@ -182,10 +182,6 @@ static void veth_release_connection(struct kobject *kobject);
 static void veth_timed_ack(unsigned long ptr);
 static void veth_timed_reset(unsigned long ptr);
 
-static struct kobj_type veth_lpar_connection_ktype = {
-        .release        = veth_release_connection
-};
-
 /*
  * Utility functions
  */
@@ -280,6 +276,81 @@ static int veth_allocate_events(HvLpIndex rlp, int number)
 }
 
 /*
+ * sysfs support
+ */
+
+struct veth_cnx_attribute {
+        struct attribute attr;
+        ssize_t (*show)(struct veth_lpar_connection *, char *buf);
+        ssize_t (*store)(struct veth_lpar_connection *, const char *buf);
+};
+
+static ssize_t veth_cnx_attribute_show(struct kobject *kobj,
+                struct attribute *attr, char *buf)
+{
+        struct veth_cnx_attribute *cnx_attr;
+        struct veth_lpar_connection *cnx;
+
+        cnx_attr = container_of(attr, struct veth_cnx_attribute, attr);
+        cnx = container_of(kobj, struct veth_lpar_connection, kobject);
+
+        if (!cnx_attr->show)
+                return -EIO;
+
+        return cnx_attr->show(cnx, buf);
+}
+
+#define CUSTOM_CNX_ATTR(_name, _format, _expression)                    \
+static ssize_t _name##_show(struct veth_lpar_connection *cnx, char *buf)\
+{                                                                       \
+        return sprintf(buf, _format, _expression);                      \
+}                                                                       \
+struct veth_cnx_attribute veth_cnx_attr_##_name = __ATTR_RO(_name)
+
+#define SIMPLE_CNX_ATTR(_name)  \
+        CUSTOM_CNX_ATTR(_name, "%lu\n", (unsigned long)cnx->_name)
+
+SIMPLE_CNX_ATTR(outstanding_tx);
+SIMPLE_CNX_ATTR(remote_lp);
+SIMPLE_CNX_ATTR(num_events);
+SIMPLE_CNX_ATTR(src_inst);
+SIMPLE_CNX_ATTR(dst_inst);
+SIMPLE_CNX_ATTR(num_pending_acks);
+SIMPLE_CNX_ATTR(num_ack_events);
+CUSTOM_CNX_ATTR(ack_timeout, "%d\n", jiffies_to_msecs(cnx->ack_timeout));
+CUSTOM_CNX_ATTR(reset_timeout, "%d\n", jiffies_to_msecs(cnx->reset_timeout));
+CUSTOM_CNX_ATTR(state, "0x%.4lX\n", cnx->state);
+CUSTOM_CNX_ATTR(last_contact, "%d\n", cnx->last_contact ?
+                jiffies_to_msecs(jiffies - cnx->last_contact) : 0);
+
+#define GET_CNX_ATTR(_name)     (&veth_cnx_attr_##_name.attr)
+
+static struct attribute *veth_cnx_default_attrs[] = {
+        GET_CNX_ATTR(outstanding_tx),
+        GET_CNX_ATTR(remote_lp),
+        GET_CNX_ATTR(num_events),
+        GET_CNX_ATTR(reset_timeout),
+        GET_CNX_ATTR(last_contact),
+        GET_CNX_ATTR(state),
+        GET_CNX_ATTR(src_inst),
+        GET_CNX_ATTR(dst_inst),
+        GET_CNX_ATTR(num_pending_acks),
+        GET_CNX_ATTR(num_ack_events),
+        GET_CNX_ATTR(ack_timeout),
+        NULL
+};
+
+static struct sysfs_ops veth_cnx_sysfs_ops = {
+                .show = veth_cnx_attribute_show
+};
+
+static struct kobj_type veth_lpar_connection_ktype = {
+        .release        = veth_release_connection,
+        .sysfs_ops      = &veth_cnx_sysfs_ops,
+        .default_attrs  = veth_cnx_default_attrs
+};
+
+/*
  * LPAR connection code
  */
 
@@ -1493,6 +1564,8 @@ void __exit veth_module_cleanup(void)
                 if (!cnx)
                         continue;
 
+                /* Remove the connection from sysfs */
+                kobject_del(&cnx->kobject);
                 /* Drop the driver's reference to the connection */
                 kobject_put(&cnx->kobject);
         }
@@ -1523,6 +1596,19 @@ int __init veth_module_init(void)
         if (rc != 0)
                 goto error;
 
+        for (i = 0; i < HVMAXARCHITECTEDLPS; ++i) {
+                struct kobject *kobj;
+
+                if (!veth_cnx[i])
+                        continue;
+
+                kobj = &veth_cnx[i]->kobject;
+                kobj->parent = &veth_driver.driver.kobj;
+                /* If the add failes, complain but otherwise continue */
+                if (0 != kobject_add(kobj))
+                        veth_error("cnx %d: Failed adding to sysfs.\n", i);
+        }
+
         return 0;
 
 error: