[PATCH net-next v5 05/13] net: ethtool: Allow passing a phy index for some commands

From: Maxime Chevallier
Date: Thu Dec 21 2023 - 13:02:53 EST


Some netlink commands are target towards ethernet PHYs, to control some
of their features. As there's several such commands, add the ability to
pass a PHY index in the ethnl request, which will populate the generic
ethnl_req_info with the relevant phydev when the command targets a PHY.

Signed-off-by: Maxime Chevallier <maxime.chevallier@xxxxxxxxxxx>
Reviewed-by: Andrew Lunn <andrew@xxxxxxx>
---
V5: - Added Andrew's R-b
- Fix a typo reported by Simon
V4: - No Changes
V3: - Fixed the documentation
V2: - New patch

Documentation/networking/ethtool-netlink.rst | 7 ++++++
include/uapi/linux/ethtool_netlink.h | 1 +
net/ethtool/netlink.c | 24 ++++++++++++++++++++
net/ethtool/netlink.h | 7 ++++--
4 files changed, 37 insertions(+), 2 deletions(-)

diff --git a/Documentation/networking/ethtool-netlink.rst b/Documentation/networking/ethtool-netlink.rst
index d583d9abf2f8..3ca6c21e74af 100644
--- a/Documentation/networking/ethtool-netlink.rst
+++ b/Documentation/networking/ethtool-netlink.rst
@@ -57,6 +57,7 @@ Structure of this header is
``ETHTOOL_A_HEADER_DEV_INDEX`` u32 device ifindex
``ETHTOOL_A_HEADER_DEV_NAME`` string device name
``ETHTOOL_A_HEADER_FLAGS`` u32 flags common for all requests
+ ``ETHTOOL_A_HEADER_PHY_INDEX`` u32 phy device index
============================== ====== =============================

``ETHTOOL_A_HEADER_DEV_INDEX`` and ``ETHTOOL_A_HEADER_DEV_NAME`` identify the
@@ -81,6 +82,12 @@ the behaviour is backward compatible, i.e. requests from old clients not aware
of the flag should be interpreted the way the client expects. A client must
not set flags it does not understand.

+``ETHTOOL_A_HEADER_PHY_INDEX`` identify the ethernet PHY the message relates to.
+As there are numerous commands that are related to PHY configuration, and because
+we can have more than one PHY on the link, the PHY index can be passed in the
+request for the commands that needs it. It is however not mandatory, and if it
+is not passed for commands that target a PHY, the net_device.phydev pointer
+is used, as a fallback that keeps the legacy behaviour.

Bit sets
========
diff --git a/include/uapi/linux/ethtool_netlink.h b/include/uapi/linux/ethtool_netlink.h
index 3f89074aa06c..422e8cfdd98c 100644
--- a/include/uapi/linux/ethtool_netlink.h
+++ b/include/uapi/linux/ethtool_netlink.h
@@ -133,6 +133,7 @@ enum {
ETHTOOL_A_HEADER_DEV_INDEX, /* u32 */
ETHTOOL_A_HEADER_DEV_NAME, /* string */
ETHTOOL_A_HEADER_FLAGS, /* u32 - ETHTOOL_FLAG_* */
+ ETHTOOL_A_HEADER_PHY_INDEX, /* u32 */

/* add new constants above here */
__ETHTOOL_A_HEADER_CNT,
diff --git a/net/ethtool/netlink.c b/net/ethtool/netlink.c
index fe3553f60bf3..1c26766ce996 100644
--- a/net/ethtool/netlink.c
+++ b/net/ethtool/netlink.c
@@ -4,6 +4,7 @@
#include <linux/ethtool_netlink.h>
#include <linux/pm_runtime.h>
#include "netlink.h"
+#include <linux/phy_link_topology.h>

static struct genl_family ethtool_genl_family;

@@ -20,6 +21,7 @@ const struct nla_policy ethnl_header_policy[] = {
.len = ALTIFNAMSIZ - 1 },
[ETHTOOL_A_HEADER_FLAGS] = NLA_POLICY_MASK(NLA_U32,
ETHTOOL_FLAGS_BASIC),
+ [ETHTOOL_A_HEADER_PHY_INDEX] = NLA_POLICY_MIN(NLA_U32, 1),
};

const struct nla_policy ethnl_header_policy_stats[] = {
@@ -28,6 +30,7 @@ const struct nla_policy ethnl_header_policy_stats[] = {
.len = ALTIFNAMSIZ - 1 },
[ETHTOOL_A_HEADER_FLAGS] = NLA_POLICY_MASK(NLA_U32,
ETHTOOL_FLAGS_STATS),
+ [ETHTOOL_A_HEADER_PHY_INDEX] = NLA_POLICY_MIN(NLA_U32, 1),
};

int ethnl_ops_begin(struct net_device *dev)
@@ -91,6 +94,7 @@ int ethnl_parse_header_dev_get(struct ethnl_req_info *req_info,
{
struct nlattr *tb[ARRAY_SIZE(ethnl_header_policy)];
const struct nlattr *devname_attr;
+ struct phy_device *phydev = NULL;
struct net_device *dev = NULL;
u32 flags = 0;
int ret;
@@ -145,6 +149,26 @@ int ethnl_parse_header_dev_get(struct ethnl_req_info *req_info,
return -EINVAL;
}

+ if (dev) {
+ if (tb[ETHTOOL_A_HEADER_PHY_INDEX]) {
+ u32 phy_index = nla_get_u32(tb[ETHTOOL_A_HEADER_PHY_INDEX]);
+
+ phydev = phy_link_topo_get_phy(&dev->link_topo,
+ phy_index);
+ if (!phydev) {
+ NL_SET_ERR_MSG_ATTR(extack, header,
+ "no phy matches phy index");
+ return -EINVAL;
+ }
+ } else {
+ /* If we need a PHY but no phy index is specified, fallback
+ * to dev->phydev
+ */
+ phydev = dev->phydev;
+ }
+ }
+
+ req_info->phydev = phydev;
req_info->dev = dev;
req_info->flags = flags;
return 0;
diff --git a/net/ethtool/netlink.h b/net/ethtool/netlink.h
index 9a333a8d04c1..def84e2def9e 100644
--- a/net/ethtool/netlink.h
+++ b/net/ethtool/netlink.h
@@ -250,6 +250,7 @@ static inline unsigned int ethnl_reply_header_size(void)
* @dev: network device the request is for (may be null)
* @dev_tracker: refcount tracker for @dev reference
* @flags: request flags common for all request types
+ * @phydev: phy_device connected to @dev this request is for (may be null)
*
* This is a common base for request specific structures holding data from
* parsed userspace request. These always embed struct ethnl_req_info at
@@ -259,6 +260,7 @@ struct ethnl_req_info {
struct net_device *dev;
netdevice_tracker dev_tracker;
u32 flags;
+ struct phy_device *phydev;
};

static inline void ethnl_parse_header_dev_put(struct ethnl_req_info *req_info)
@@ -395,9 +397,10 @@ extern const struct ethnl_request_ops ethnl_rss_request_ops;
extern const struct ethnl_request_ops ethnl_plca_cfg_request_ops;
extern const struct ethnl_request_ops ethnl_plca_status_request_ops;
extern const struct ethnl_request_ops ethnl_mm_request_ops;
+extern const struct ethnl_request_ops ethnl_phy_request_ops;

-extern const struct nla_policy ethnl_header_policy[ETHTOOL_A_HEADER_FLAGS + 1];
-extern const struct nla_policy ethnl_header_policy_stats[ETHTOOL_A_HEADER_FLAGS + 1];
+extern const struct nla_policy ethnl_header_policy[ETHTOOL_A_HEADER_PHY_INDEX + 1];
+extern const struct nla_policy ethnl_header_policy_stats[ETHTOOL_A_HEADER_PHY_INDEX + 1];
extern const struct nla_policy ethnl_strset_get_policy[ETHTOOL_A_STRSET_COUNTS_ONLY + 1];
extern const struct nla_policy ethnl_linkinfo_get_policy[ETHTOOL_A_LINKINFO_HEADER + 1];
extern const struct nla_policy ethnl_linkinfo_set_policy[ETHTOOL_A_LINKINFO_TP_MDIX_CTRL + 1];
--
2.43.0