[PATCH net-next 06/11] net: dsa: rework switch addition and removal

[Vivien Didelot]

This patch removes the unnecessary index argument from the
dsa_dst_add_ds and dsa_dst_del_ds functions and renames them to
dsa_tree_add_switch and dsa_tree_remove_switch respectively.

In addition to a more explicit scope, we now check the presence of an
existing switch with the same index directly within dsa_tree_add_switch.

Signed-off-by: Vivien Didelot <vivien.dide...@savoirfairelinux.com>
---
 net/dsa/dsa2.c | 47 +++++++++++++++++++++++++++--------------------
 1 file changed, 27 insertions(+), 20 deletions(-)

diff --git a/net/dsa/dsa2.c b/net/dsa/dsa2.c
index bda222cfc02c..5b6a3dad8015 100644
--- a/net/dsa/dsa2.c
+++ b/net/dsa/dsa2.c
@@ -94,20 +94,6 @@ static void dsa_tree_put(struct dsa_switch_tree *dst)
        kref_put(&dst->refcount, dsa_tree_release);
 }
 
-static void dsa_dst_add_ds(struct dsa_switch_tree *dst,
-                          struct dsa_switch *ds, u32 index)
-{
-       dsa_tree_get(dst);
-       dst->ds[index] = ds;
-}
-
-static void dsa_dst_del_ds(struct dsa_switch_tree *dst,
-                          struct dsa_switch *ds, u32 index)
-{
-       dst->ds[index] = NULL;
-       dsa_tree_put(dst);
-}
-
 /* For platform data configurations, we need to have a valid name argument to
  * differentiate a disabled port from an enabled one
  */
@@ -484,6 +470,27 @@ static void dsa_dst_unapply(struct dsa_switch_tree *dst)
        dst->applied = false;
 }
 
+static void dsa_tree_remove_switch(struct dsa_switch_tree *dst,
+                                  unsigned int index)
+{
+       dst->ds[index] = NULL;
+       dsa_tree_put(dst);
+}
+
+static int dsa_tree_add_switch(struct dsa_switch_tree *dst,
+                              struct dsa_switch *ds)
+{
+       unsigned int index = ds->index;
+
+       if (dst->ds[index])
+               return -EBUSY;
+
+       dsa_tree_get(dst);
+       dst->ds[index] = ds;
+
+       return 0;
+}
+
 static int dsa_cpu_parse(struct dsa_port *port, u32 index,
                         struct dsa_switch_tree *dst,
                         struct dsa_switch *ds)
@@ -762,9 +769,6 @@ static int _dsa_register_switch(struct dsa_switch *ds)
        if (!dst)
                return -ENOMEM;
 
-       if (dst->ds[index])
-               return -EBUSY;
-
        ds->dst = dst;
        ds->index = index;
        ds->cd = pdata;
@@ -773,7 +777,9 @@ static int _dsa_register_switch(struct dsa_switch *ds)
        for (i = 0; i < DSA_MAX_SWITCHES; ++i)
                ds->rtable[i] = DSA_RTABLE_NONE;
 
-       dsa_dst_add_ds(dst, ds, index);
+       err = dsa_tree_add_switch(dst, ds);
+       if (err)
+               return err;
 
        err = dsa_dst_complete(dst);
        if (err < 0)
@@ -801,7 +807,7 @@ static int _dsa_register_switch(struct dsa_switch *ds)
        return 0;
 
 out_del_dst:
-       dsa_dst_del_ds(dst, ds, ds->index);
+       dsa_tree_remove_switch(dst, index);
 
        return err;
 }
@@ -843,10 +849,11 @@ EXPORT_SYMBOL_GPL(dsa_register_switch);
 static void _dsa_unregister_switch(struct dsa_switch *ds)
 {
        struct dsa_switch_tree *dst = ds->dst;
+       unsigned int index = ds->index;
 
        dsa_dst_unapply(dst);
 
-       dsa_dst_del_ds(dst, ds, ds->index);
+       dsa_tree_remove_switch(dst, index);
 }
 
 void dsa_unregister_switch(struct dsa_switch *ds)
-- 
2.14.3