[PATCH net-next] net: dsa: mv88e6xxx: rework port state setter

From: Vivien Didelot
Date: Mon Mar 07 2016 - 18:24:58 EST


Apply a few non-functional changes on the port state setter:

* add a dynamic debug message with state names to track changes
* explicit states checking instead of assuming their numeric values
* lock mutex only once when changing several port states
* use bitmap macros to declare and access port_state_update_mask

Signed-off-by: Vivien Didelot <vivien.didelot@xxxxxxxxxxxxxxxxxxxx>
---
drivers/net/dsa/mv88e6xxx.c | 54 +++++++++++++++++++++++++++------------------
drivers/net/dsa/mv88e6xxx.h | 2 +-
2 files changed, 34 insertions(+), 22 deletions(-)

diff --git a/drivers/net/dsa/mv88e6xxx.c b/drivers/net/dsa/mv88e6xxx.c
index d11c9d5..3a58a8a 100644
--- a/drivers/net/dsa/mv88e6xxx.c
+++ b/drivers/net/dsa/mv88e6xxx.c
@@ -1051,39 +1051,49 @@ static int _mv88e6xxx_atu_remove(struct dsa_switch *ds, u16 fid, int port,
return _mv88e6xxx_atu_move(ds, fid, port, 0x0f, static_too);
}

-static int mv88e6xxx_set_port_state(struct dsa_switch *ds, int port, u8 state)
+static const char * const mv88e6xxx_port_state_names[] = {
+ [PORT_CONTROL_STATE_DISABLED] = "Disabled",
+ [PORT_CONTROL_STATE_BLOCKING] = "Blocking/Listening",
+ [PORT_CONTROL_STATE_LEARNING] = "Learning",
+ [PORT_CONTROL_STATE_FORWARDING] = "Forwarding",
+};
+
+static int _mv88e6xxx_port_state(struct dsa_switch *ds, int port, u8 state)
{
- struct mv88e6xxx_priv_state *ps = ds_to_priv(ds);
int reg, ret = 0;
u8 oldstate;

- mutex_lock(&ps->smi_mutex);
-
reg = _mv88e6xxx_reg_read(ds, REG_PORT(port), PORT_CONTROL);
- if (reg < 0) {
- ret = reg;
- goto abort;
- }
+ if (reg < 0)
+ return reg;

oldstate = reg & PORT_CONTROL_STATE_MASK;
+
if (oldstate != state) {
/* Flush forwarding database if we're moving a port
* from Learning or Forwarding state to Disabled or
* Blocking or Listening state.
*/
- if (oldstate >= PORT_CONTROL_STATE_LEARNING &&
- state <= PORT_CONTROL_STATE_BLOCKING) {
+ if ((oldstate == PORT_CONTROL_STATE_LEARNING ||
+ oldstate == PORT_CONTROL_STATE_FORWARDING)
+ && (state == PORT_CONTROL_STATE_DISABLED ||
+ state == PORT_CONTROL_STATE_BLOCKING)) {
ret = _mv88e6xxx_atu_remove(ds, 0, port, false);
if (ret)
- goto abort;
+ return ret;
}
+
reg = (reg & ~PORT_CONTROL_STATE_MASK) | state;
ret = _mv88e6xxx_reg_write(ds, REG_PORT(port), PORT_CONTROL,
reg);
+ if (ret)
+ return ret;
+
+ netdev_dbg(ds->ports[port], "PortState %s (was %s)\n",
+ mv88e6xxx_port_state_names[state],
+ mv88e6xxx_port_state_names[oldstate]);
}

-abort:
- mutex_unlock(&ps->smi_mutex);
return ret;
}

@@ -1146,13 +1156,11 @@ int mv88e6xxx_port_stp_update(struct dsa_switch *ds, int port, u8 state)
break;
}

- netdev_dbg(ds->ports[port], "port state %d [%d]\n", state, stp_state);
-
/* mv88e6xxx_port_stp_update may be called with softirqs disabled,
* so we can not update the port state directly but need to schedule it.
*/
ps->ports[port].state = stp_state;
- set_bit(port, &ps->port_state_update_mask);
+ set_bit(port, ps->port_state_update_mask);
schedule_work(&ps->bridge_work);

return 0;
@@ -2228,11 +2236,15 @@ static void mv88e6xxx_bridge_work(struct work_struct *work)
ps = container_of(work, struct mv88e6xxx_priv_state, bridge_work);
ds = ((struct dsa_switch *)ps) - 1;

- while (ps->port_state_update_mask) {
- port = __ffs(ps->port_state_update_mask);
- clear_bit(port, &ps->port_state_update_mask);
- mv88e6xxx_set_port_state(ds, port, ps->ports[port].state);
- }
+ mutex_lock(&ps->smi_mutex);
+
+ for (port = 0; port < ps->num_ports; ++port)
+ if (test_and_clear_bit(port, ps->port_state_update_mask) &&
+ _mv88e6xxx_port_state(ds, port, ps->ports[port].state))
+ netdev_warn(ds->ports[port], "failed to update state to %s\n",
+ mv88e6xxx_port_state_names[ps->ports[port].state]);
+
+ mutex_unlock(&ps->smi_mutex);
}

static int mv88e6xxx_setup_port(struct dsa_switch *ds, int port)
diff --git a/drivers/net/dsa/mv88e6xxx.h b/drivers/net/dsa/mv88e6xxx.h
index d7b088d..3425616 100644
--- a/drivers/net/dsa/mv88e6xxx.h
+++ b/drivers/net/dsa/mv88e6xxx.h
@@ -426,7 +426,7 @@ struct mv88e6xxx_priv_state {

struct mv88e6xxx_priv_port ports[DSA_MAX_PORTS];

- unsigned long port_state_update_mask;
+ DECLARE_BITMAP(port_state_update_mask, DSA_MAX_PORTS);

struct work_struct bridge_work;
};
--
2.7.2