[PATCH net-next v2] net: dsa: Mock-up driver
This patch adds support for a DSA mock-up driver which essentially does
the following:
- registers/unregisters 4 fixed PHYs to the slave network devices
- uses eth0 (configurable) as the master netdev
- registers the switch as a fixed MDIO device against the fixed MDIO bus
at address 31
- includes dynamic debug prints for dsa_switch_ops functions that can be
enabled to get call traces
This is a good way to test modular builds as well as exercise the DSA
APIs without requiring access to real hardware. This does not test the
data-path, although this could be added later on.
Signed-off-by: Florian Fainelli
---
Changes in v2;
- removed an unnecessary change to include/linux/fixed_phy.h
drivers/net/dsa/Kconfig | 8 +
drivers/net/dsa/Makefile | 2 +-
drivers/net/dsa/dsa_loop.c| 329 ++
drivers/net/dsa/dsa_loop.h| 19 +++
drivers/net/dsa/dsa_loop_bdinfo.c | 34
5 files changed, 391 insertions(+), 1 deletion(-)
create mode 100644 drivers/net/dsa/dsa_loop.c
create mode 100644 drivers/net/dsa/dsa_loop.h
create mode 100644 drivers/net/dsa/dsa_loop_bdinfo.c
diff --git a/drivers/net/dsa/Kconfig b/drivers/net/dsa/Kconfig
index 564b267c8428..ba2e655eec19 100644
--- a/drivers/net/dsa/Kconfig
+++ b/drivers/net/dsa/Kconfig
@@ -34,4 +34,12 @@ config NET_DSA_QCA8K
This enables support for the Qualcomm Atheros QCA8K Ethernet
switch chips.
+config NET_DSA_LOOP
+ tristate "DSA mock-up Ethernet switch chip support"
+ depends on NET_DSA
+ select FIXED_PHY
+ ---help---
+ This enables support for a fake mock-up switch chip which
+ exercises the DSA APIs.
+
endmenu
diff --git a/drivers/net/dsa/Makefile b/drivers/net/dsa/Makefile
index a3c941632217..5c8830991041 100644
--- a/drivers/net/dsa/Makefile
+++ b/drivers/net/dsa/Makefile
@@ -2,6 +2,6 @@ obj-$(CONFIG_NET_DSA_MV88E6060) += mv88e6060.o
obj-$(CONFIG_NET_DSA_BCM_SF2) += bcm-sf2.o
bcm-sf2-objs := bcm_sf2.o bcm_sf2_cfp.o
obj-$(CONFIG_NET_DSA_QCA8K)+= qca8k.o
-
obj-y += b53/
obj-y += mv88e6xxx/
+obj-$(CONFIG_NET_DSA_LOOP) += dsa_loop.o dsa_loop_bdinfo.o
diff --git a/drivers/net/dsa/dsa_loop.c b/drivers/net/dsa/dsa_loop.c
new file mode 100644
index ..0a9a2f846efd
--- /dev/null
+++ b/drivers/net/dsa/dsa_loop.c
@@ -0,0 +1,329 @@
+/*
+ * Distributed Switch Architecture loopback driver
+ *
+ * Copyright (C) 2016, Florian Fainelli
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+
+#include "dsa_loop.h"
+
+struct dsa_loop_vlan {
+ u16 members;
+ u16 untagged;
+};
+
+#define DSA_LOOP_VLANS 5
+
+struct dsa_loop_priv {
+ struct mii_bus *bus;
+ unsigned intport_base;
+ struct dsa_loop_vlan vlans[DSA_LOOP_VLANS];
+ struct net_device *netdev;
+ u16 pvid;
+};
+
+static struct phy_device *phydevs[PHY_MAX_ADDR];
+
+static enum dsa_tag_protocol dsa_loop_get_protocol(struct dsa_switch *ds)
+{
+ dev_dbg(ds->dev, "%s\n", __func__);
+
+ return DSA_TAG_PROTO_NONE;
+}
+
+static int dsa_loop_setup(struct dsa_switch *ds)
+{
+ dev_dbg(ds->dev, "%s\n", __func__);
+
+ return 0;
+}
+
+static int dsa_loop_set_addr(struct dsa_switch *ds, u8 *addr)
+{
+ dev_dbg(ds->dev, "%s\n", __func__);
+
+ return 0;
+}
+
+static int dsa_loop_phy_read(struct dsa_switch *ds, int port, int regnum)
+{
+ struct dsa_loop_priv *ps = ds->priv;
+ struct mii_bus *bus = ps->bus;
+
+ dev_dbg(ds->dev, "%s\n", __func__);
+
+ return mdiobus_read_nested(bus, ps->port_base + port, regnum);
+}
+
+static int dsa_loop_phy_write(struct dsa_switch *ds, int port,
+ int regnum, u16 value)
+{
+ struct dsa_loop_priv *ps = ds->priv;
+ struct mii_bus *bus = ps->bus;
+
+ dev_dbg(ds->dev, "%s\n", __func__);
+
+ return mdiobus_write_nested(bus, ps->port_base + port, regnum, value);
+}
+
+static int dsa_loop_port_bridge_join(struct dsa_switch *ds, int port,
+struct net_device *bridge)
+{
+ dev_dbg(ds->dev, "%s\n", __func__);
+
+ return 0;
+}
+
+static void dsa_loop_port_bridge_leave(struct dsa_switch *ds, int port,
+ struct net_device *bridge)
+{
+ dev_dbg(ds->dev, "%s\n", __func__);
+}
+
+static void dsa_loop_port_stp_state_set(struct dsa_switch *ds, int port,
+ u8 state)
+{
+ dev_dbg(ds->dev, "%s\n", __func__);
+}
+
+static int dsa_loop_port_vlan_filtering(struct dsa_switch *ds, int port,
+
Re: [PATCH net-next v2] net: dsa: Mock-up driver
Hi Florian
> +static enum dsa_tag_protocol dsa_loop_get_protocol(struct dsa_switch *ds)
> +{
> + dev_dbg(ds->dev, "%s\n", __func__);
> +
> + return DSA_TAG_PROTO_NONE;
> +}
I'm wondering how safe this is:
static const struct dsa_device_ops none_ops = {
.xmit = dsa_slave_notag_xmit,
.rcv= NULL,
};
/*
* If the CPU connects to this switch, set the switch tree
* tagging protocol to the preferred tagging format of this
* switch.
*/
if (dst->cpu_switch == ds) {
enum dsa_tag_protocol tag_protocol;
tag_protocol = ops->get_tag_protocol(ds);
dst->tag_ops = dsa_resolve_tag_protocol(tag_protocol);
if (IS_ERR(dst->tag_ops))
return PTR_ERR(dst->tag_ops);
dst->rcv = dst->tag_ops->rcv;
}
static int dsa_switch_rcv(struct sk_buff *skb, struct net_device *dev,
struct packet_type *pt, struct net_device *orig_dev)
{
struct dsa_switch_tree *dst = dev->dsa_ptr;
if (unlikely(dst == NULL)) {
kfree_skb(skb);
return 0;
}
return dst->rcv(skb, dev, pt, orig_dev);
}
static struct packet_type dsa_pack_type __read_mostly = {
.type = cpu_to_be16(ETH_P_XDSA),
.func = dsa_switch_rcv,
};
It looks like when a frame is received, we are going to dereference a
NULL pointer.
Either we need a NOP rcv function, or we don't register dsa_pack_type
if rcv is NULL.
Andrew
Re: [PATCH net-next v2] net: dsa: Mock-up driver
Hi Andrew,
On 03/31/2017 09:06 AM, Andrew Lunn wrote:
> Hi Florian
>
>> +static enum dsa_tag_protocol dsa_loop_get_protocol(struct dsa_switch *ds)
>> +{
>> +dev_dbg(ds->dev, "%s\n", __func__);
>> +
>> +return DSA_TAG_PROTO_NONE;
>> +}
>
> I'm wondering how safe this is:
>
> static const struct dsa_device_ops none_ops = {
> .xmit = dsa_slave_notag_xmit,
> .rcv= NULL,
> };
>
> /*
> * If the CPU connects to this switch, set the switch tree
> * tagging protocol to the preferred tagging format of this
> * switch.
> */
> if (dst->cpu_switch == ds) {
> enum dsa_tag_protocol tag_protocol;
>
> tag_protocol = ops->get_tag_protocol(ds);
> dst->tag_ops = dsa_resolve_tag_protocol(tag_protocol);
> if (IS_ERR(dst->tag_ops))
> return PTR_ERR(dst->tag_ops);
>
> dst->rcv = dst->tag_ops->rcv;
> }
>
>
> static int dsa_switch_rcv(struct sk_buff *skb, struct net_device *dev,
> struct packet_type *pt, struct net_device *orig_dev)
> {
> struct dsa_switch_tree *dst = dev->dsa_ptr;
>
> if (unlikely(dst == NULL)) {
> kfree_skb(skb);
> return 0;
> }
>
> return dst->rcv(skb, dev, pt, orig_dev);
> }
>
> static struct packet_type dsa_pack_type __read_mostly = {
> .type = cpu_to_be16(ETH_P_XDSA),
> .func = dsa_switch_rcv,
> };
>
> It looks like when a frame is received, we are going to dereference a
> NULL pointer.
Actually we do not, because netdev_uses_dsa() returns true only when
dst->rcv is different from NULL. When dst->rcv is NULL we completely
bypass the DSA hook in eth_type_trans() and everything is well, the
master network device is the one receiving packets.
This is actually the intended behavior for netdev_uses_dsa() because it
really tells whether there is a DSA tagging protocol set-up and that is
what NIC drivers (e.g: bcmsysport) would care about.
Thanks!
--
Florian
Re: [PATCH net-next v2] net: dsa: Mock-up driver
> Actually we do not, because netdev_uses_dsa() returns true only when
> dst->rcv is different from NULL. When dst->rcv is NULL we completely
> bypass the DSA hook in eth_type_trans() and everything is well, the
> master network device is the one receiving packets.
static inline bool netdev_uses_dsa(struct net_device *dev)
{
#if IS_ENABLED(CONFIG_NET_DSA)
if (dev->dsa_ptr != NULL)
return dsa_uses_tagged_protocol(dev->dsa_ptr);
#endif
return false;
}
and
static inline bool dsa_uses_tagged_protocol(struct dsa_switch_tree *dst)
{
return dst->rcv != NULL;
}
Yep, i just needed to dig further...
Thanks
Andrew
Re: [PATCH net-next v2] net: dsa: Mock-up driver
From: Florian Fainelli Date: Thu, 30 Mar 2017 18:43:21 -0700 > This patch adds support for a DSA mock-up driver which essentially does > the following: > > - registers/unregisters 4 fixed PHYs to the slave network devices > - uses eth0 (configurable) as the master netdev > - registers the switch as a fixed MDIO device against the fixed MDIO bus > at address 31 > - includes dynamic debug prints for dsa_switch_ops functions that can be > enabled to get call traces > > This is a good way to test modular builds as well as exercise the DSA > APIs without requiring access to real hardware. This does not test the > data-path, although this could be added later on. > > Signed-off-by: Florian Fainelli > --- > Changes in v2; > > - removed an unnecessary change to include/linux/fixed_phy.h This looks extremely useful, applied, thanks!
