[RFC PATCH v9 06/10] netdev: expose DPLL pin handle for netdevice

Arkadiusz Kubalewski
2023-06-23T12:45:07Z

From: Jiri Pirko <jiri@nvidia.com>

In case netdevice represents a SyncE port, the user needs to understand
the connection between netdevice and associated DPLL pin. There might me
multiple netdevices pointing to the same pin, in case of VF/SF
implementation.

Add a IFLA Netlink attribute to nest the DPLL pin handle, similar to
how it is implemented for devlink port. Add a struct dpll_pin pointer
to netdev and protect access to it by RTNL. Expose netdev_dpll_pin_set()
and netdev_dpll_pin_clear() helpers to the drivers so they can set/clear
the DPLL pin relationship to netdev.

Note that during the lifetime of struct dpll_pin the pin handle does not
change. Therefore it is save to access it lockless. It is drivers
responsibility to call netdev_dpll_pin_clear() before dpll_pin_put().

Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: Arkadiusz Kubalewski <arkadiusz.kubalewski@intel.com>
---
drivers/dpll/dpll_netlink.c | 7 ++++---
include/linux/dpll.h | 20 ++++++++++++++++++++
include/linux/netdevice.h | 20 ++++++++++++++++++++
include/uapi/linux/if_link.h | 2 ++
net/core/dev.c | 22 ++++++++++++++++++++++
net/core/rtnetlink.c | 35 +++++++++++++++++++++++++++++++++++
6 files changed, 103 insertions(+), 3 deletions(-)

diff --git a/drivers/dpll/dpll_netlink.c b/drivers/dpll/dpll_netlink.c
index 58ee4a88b301..de90861d765d 100644
--- a/drivers/dpll/dpll_netlink.c
+++ b/drivers/dpll/dpll_netlink.c
@@ -66,6 +66,7 @@ int dpll_msg_add_pin_handle(struct sk_buff *msg, struct dpll_pin *pin)
return -EMSGSIZE;
return 0;
}
+EXPORT_SYMBOL_GPL(dpll_msg_add_pin_handle);

static int
dpll_msg_add_mode(struct sk_buff *msg, struct dpll_device *dpll,
@@ -265,10 +266,9 @@ dpll_msg_add_pin_parents(struct sk_buff *msg, struct dpll_pin *pin,
nest = nla_nest_start(msg, DPLL_A_PIN_PARENT_PIN);
if (!nest)
return -EMSGSIZE;
- if (nla_put_u32(msg, DPLL_A_PIN_ID, ppin->id)) {
- ret = -EMSGSIZE;
+ ret = dpll_msg_add_pin_handle(msg, ppin);
+ if (ret)
goto nest_cancel;
- }
if (nla_put_u8(msg, DPLL_A_PIN_STATE, state)) {
ret = -EMSGSIZE;
goto nest_cancel;
@@ -328,6 +328,7 @@ dpll_cmd_pin_get_one(struct sk_buff *msg, struct dpll_pin *pin,

ref = dpll_xa_ref_dpll_first(&pin->dpll_refs);
ASSERT_NOT_NULL(ref);
+
ret = dpll_msg_add_pin_handle(msg, pin);
if (ret)
return ret;
diff --git a/include/linux/dpll.h b/include/linux/dpll.h
index a18bcaa13553..8d085dc92cdd 100644
--- a/include/linux/dpll.h
+++ b/include/linux/dpll.h
@@ -108,6 +108,26 @@ struct dpll_pin_properties {
struct dpll_pin_frequency *freq_supported;
};

+#if IS_ENABLED(CONFIG_DPLL)
+
+size_t dpll_msg_pin_handle_size(struct dpll_pin *pin);
+
+int dpll_msg_add_pin_handle(struct sk_buff *msg, struct dpll_pin *pin);
+
+#else
+
+static inline size_t dpll_msg_pin_handle_size(struct dpll_pin *pin)
+{
+ return 0;
+}
+
+static inline int dpll_msg_add_pin_handle(struct sk_buff *msg, struct dpll_pin *pin)
+{
+ return 0;
+}
+
+#endif
+
struct dpll_device
*dpll_device_get(u64 clock_id, u32 dev_driver_id, struct module *module);

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index acf706d49c2b..99bfc427ffee 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -34,6 +34,7 @@
#include <linux/rculist.h>
#include <linux/workqueue.h>
#include <linux/dynamic_queue_limits.h>
+#include <linux/dpll.h>

#include <net/net_namespace.h>
#ifdef CONFIG_DCB
@@ -2058,6 +2059,9 @@ enum netdev_ml_priv_type {
* SET_NETDEV_DEVLINK_PORT macro. This pointer is static
* during the time netdevice is registered.
*
+ * @dpll_pin: Pointer to the SyncE source pin of a DPLL subsystem,
+ * where the clock is recovered.
+ *
* FIXME: cleanup struct net_device such that network protocol info
* moves out.
*/
@@ -2414,6 +2418,10 @@ struct net_device {
struct rtnl_hw_stats64 *offload_xstats_l3;

struct devlink_port *devlink_port;
+
+#if IS_ENABLED(CONFIG_DPLL)
+ struct dpll_pin *dpll_pin;
+#endif
};
#define to_net_dev(d) container_of(d, struct net_device, dev)

@@ -3961,6 +3969,18 @@ int dev_get_mac_address(struct sockaddr *sa, struct net *net, char *dev_name);
int dev_get_port_parent_id(struct net_device *dev,
struct netdev_phys_item_id *ppid, bool recurse);
bool netdev_port_same_parent_id(struct net_device *a, struct net_device *b);
+void netdev_dpll_pin_set(struct net_device *dev, struct dpll_pin *dpll_pin);
+void netdev_dpll_pin_clear(struct net_device *dev);
+
+static inline struct dpll_pin *netdev_dpll_pin(const struct net_device *dev)
+{
+#if IS_ENABLED(CONFIG_DPLL)
+ return dev->dpll_pin;
+#else
+ return NULL;
+#endif
+}
+
struct sk_buff *validate_xmit_skb_list(struct sk_buff *skb, struct net_device *dev, bool *again);
struct sk_buff *dev_hard_start_xmit(struct sk_buff *skb, struct net_device *dev,
struct netdev_queue *txq, int *ret);
diff --git a/include/uapi/linux/if_link.h b/include/uapi/linux/if_link.h
index 0f6a0fe09bdb..be03c8292cd7 100644
--- a/include/uapi/linux/if_link.h
+++ b/include/uapi/linux/if_link.h
@@ -377,6 +377,8 @@ enum {
IFLA_GSO_IPV4_MAX_SIZE,
IFLA_GRO_IPV4_MAX_SIZE,

+ IFLA_DPLL_PIN,
+
__IFLA_MAX
};

diff --git a/net/core/dev.c b/net/core/dev.c
index e4ff0adf5523..2cf2d9a00feb 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -8956,6 +8956,28 @@ bool netdev_port_same_parent_id(struct net_device *a, struct net_device *b)
}
EXPORT_SYMBOL(netdev_port_same_parent_id);

+static void netdev_dpll_pin_assign(struct net_device *dev, struct dpll_pin *dpll_pin)
+{
+#if IS_ENABLED(CONFIG_DPLL)
+ rtnl_lock();
+ dev->dpll_pin = dpll_pin;
+ rtnl_unlock();
+#endif
+}
+
+void netdev_dpll_pin_set(struct net_device *dev, struct dpll_pin *dpll_pin)
+{
+ WARN_ON(!dpll_pin);
+ netdev_dpll_pin_assign(dev, dpll_pin);
+}
+EXPORT_SYMBOL(netdev_dpll_pin_set);
+
+void netdev_dpll_pin_clear(struct net_device *dev)
+{
+ netdev_dpll_pin_assign(dev, NULL);
+}
+EXPORT_SYMBOL(netdev_dpll_pin_clear);
+
/**
* dev_change_proto_down - set carrier according to proto_down.
*
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 2c61fb912772..48ce14306f28 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -1055,6 +1055,15 @@ static size_t rtnl_devlink_port_size(const struct net_device *dev)
return size;
}

+static size_t rtnl_dpll_pin_size(const struct net_device *dev)
+{
+ size_t size = nla_total_size(0); /* nest IFLA_DPLL_PIN */
+
+ size += dpll_msg_pin_handle_size(netdev_dpll_pin(dev));
+
+ return size;
+}
+
static noinline size_t if_nlmsg_size(const struct net_device *dev,
u32 ext_filter_mask)
{
@@ -1111,6 +1120,7 @@ static noinline size_t if_nlmsg_size(const struct net_device *dev,
+ rtnl_prop_list_size(dev)
+ nla_total_size(MAX_ADDR_LEN) /* IFLA_PERM_ADDRESS */
+ rtnl_devlink_port_size(dev)
+ + rtnl_dpll_pin_size(dev)
+ 0;
}

@@ -1775,6 +1785,28 @@ static int rtnl_fill_devlink_port(struct sk_buff *skb,
return ret;
}

+static int rtnl_fill_dpll_pin(struct sk_buff *skb,
+ const struct net_device *dev)
+{
+ struct nlattr *dpll_pin_nest;
+ int ret;
+
+ dpll_pin_nest = nla_nest_start(skb, IFLA_DPLL_PIN);
+ if (!dpll_pin_nest)
+ return -EMSGSIZE;
+
+ ret = dpll_msg_add_pin_handle(skb, netdev_dpll_pin(dev));
+ if (ret < 0)
+ goto nest_cancel;
+
+ nla_nest_end(skb, dpll_pin_nest);
+ return 0;
+
+nest_cancel:
+ nla_nest_cancel(skb, dpll_pin_nest);
+ return ret;
+}
+
static int rtnl_fill_ifinfo(struct sk_buff *skb,
struct net_device *dev, struct net *src_net,
int type, u32 pid, u32 seq, u32 change,
@@ -1917,6 +1949,9 @@ static int rtnl_fill_ifinfo(struct sk_buff *skb,
if (rtnl_fill_devlink_port(skb, dev))
goto nla_put_failure;

+ if (rtnl_fill_dpll_pin(skb, dev))
+ goto nla_put_failure;
+
nlmsg_end(skb, nlh);
return 0;

--
2.39.3