ethtool: refactor checking max channels

Currently ethtool_set_channel calls separate functions to check whether
the new channel number violates rss configuration or flow steering
configuration.

Very soon we need to check whether the new channel number violates
memory provider configuration as well.

To do all 3 checks cleanly, add a wrapper around
ethtool_get_max_rxnfc_channel() and ethtool_get_max_rxfh_channel(),
which does both checks. We can later extend this wrapper to add the
memory provider check in one place.

Note that in the current code, we put a descriptive genl error message
when we run into issues. To preserve the error message, we pass the
genl_info* to the common helper. The ioctl calls can pass NULL instead.

Suggested-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Mina Almasry <almasrymina@google.com>
Link: https://patch.msgid.link/20240808205345.2141858-1-almasrymina@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/net/ethtool/channels.c b/net/ethtool/channels.c
index cee188da54f85f147853971c5bab0498f6247346..ca4f80282448b680543e1b579adb1de6d67ade11 100644 (file)
--- a/net/ethtool/channels.c
+++ b/net/ethtool/channels.c
@@ -114,8 +114,7 @@ ethnl_set_channels(struct ethnl_req_info *req_info, struct genl_info *info)
        struct net_device *dev = req_info->dev;
        struct ethtool_channels channels = {};
        struct nlattr **tb = info->attrs;
-       u32 err_attr, max_rxfh_in_use;
-       u64 max_rxnfc_in_use;
+       u32 err_attr;
        int ret;
 
        dev->ethtool_ops->get_channels(dev, &channels);
@@ -166,20 +165,9 @@ ethnl_set_channels(struct ethnl_req_info *req_info, struct genl_info *info)
                return -EINVAL;
        }
 
-       /* ensure the new Rx count fits within the configured Rx flow
-        * indirection table/rxnfc settings
-        */
-       if (ethtool_get_max_rxnfc_channel(dev, &max_rxnfc_in_use))
-               max_rxnfc_in_use = 0;
-       max_rxfh_in_use = ethtool_get_max_rxfh_channel(dev);
-       if (channels.combined_count + channels.rx_count <= max_rxfh_in_use) {
-               GENL_SET_ERR_MSG_FMT(info, "requested channel counts are too low for existing indirection table (%d)", max_rxfh_in_use);
-               return -EINVAL;
-       }
-       if (channels.combined_count + channels.rx_count <= max_rxnfc_in_use) {
-               GENL_SET_ERR_MSG(info, "requested channel counts are too low for existing ntuple filter settings");
-               return -EINVAL;
-       }
+       ret = ethtool_check_max_channel(dev, channels, info);
+       if (ret)
+               return ret;
 
        /* Disabling channels, query zero-copy AF_XDP sockets */
        from_channel = channels.combined_count +

diff --git a/net/ethtool/common.c b/net/ethtool/common.c
index 5f714bbbef195c438c08e5ab8a2fa62b6ce8e2a9..7257ae272296f95a8a665096e7ccb067eabd5707 100644 (file)
--- a/net/ethtool/common.c
+++ b/net/ethtool/common.c
@@ -6,6 +6,7 @@
 #include <linux/rtnetlink.h>
 #include <linux/ptp_clock_kernel.h>
 
+#include "netlink.h"
 #include "common.h"
 
 const char netdev_features_strings[NETDEV_FEATURE_COUNT][ETH_GSTRING_LEN] = {
@@ -539,7 +540,7 @@ static int ethtool_get_rxnfc_rule_count(struct net_device *dev)
        return info.rule_cnt;
 }
 
-int ethtool_get_max_rxnfc_channel(struct net_device *dev, u64 *max)
+static int ethtool_get_max_rxnfc_channel(struct net_device *dev, u64 *max)
 {
        const struct ethtool_ops *ops = dev->ethtool_ops;
        struct ethtool_rxnfc *info;
@@ -609,7 +610,7 @@ static u32 ethtool_get_max_rss_ctx_channel(struct net_device *dev)
        return max_ring;
 }
 
-u32 ethtool_get_max_rxfh_channel(struct net_device *dev)
+static u32 ethtool_get_max_rxfh_channel(struct net_device *dev)
 {
        struct ethtool_rxfh_param rxfh = {};
        u32 dev_size, current_max;
@@ -650,6 +651,33 @@ out_free:
        return current_max;
 }
 
+int ethtool_check_max_channel(struct net_device *dev,
+                             struct ethtool_channels channels,
+                             struct genl_info *info)
+{
+       u64 max_rxnfc_in_use;
+       u32 max_rxfh_in_use;
+
+       /* ensure the new Rx count fits within the configured Rx flow
+        * indirection table/rxnfc settings
+        */
+       if (ethtool_get_max_rxnfc_channel(dev, &max_rxnfc_in_use))
+               max_rxnfc_in_use = 0;
+       max_rxfh_in_use = ethtool_get_max_rxfh_channel(dev);
+       if (channels.combined_count + channels.rx_count <= max_rxfh_in_use) {
+               if (info)
+                       GENL_SET_ERR_MSG_FMT(info, "requested channel counts are too low for existing indirection table (%d)", max_rxfh_in_use);
+               return -EINVAL;
+       }
+       if (channels.combined_count + channels.rx_count <= max_rxnfc_in_use) {
+               if (info)
+                       GENL_SET_ERR_MSG(info, "requested channel counts are too low for existing ntuple filter settings");
+               return -EINVAL;
+       }
+
+       return 0;
+}
+
 int ethtool_check_ops(const struct ethtool_ops *ops)
 {
        if (WARN_ON(ops->set_coalesce && !ops->supported_coalesce_params))

diff --git a/net/ethtool/common.h b/net/ethtool/common.h
index 863806fcf01ae6d04fada8adec91276853ec62e6..d55d5201b085da67da1493aca3c8cec9cc092375 100644 (file)
--- a/net/ethtool/common.h
+++ b/net/ethtool/common.h
@@ -20,6 +20,8 @@ struct link_mode_info {
        u8                              duplex;
 };
 
+struct genl_info;
+
 extern const char
 netdev_features_strings[NETDEV_FEATURE_COUNT][ETH_GSTRING_LEN];
 extern const char
@@ -42,8 +44,9 @@ int __ethtool_get_link(struct net_device *dev);
 bool convert_legacy_settings_to_link_ksettings(
        struct ethtool_link_ksettings *link_ksettings,
        const struct ethtool_cmd *legacy_settings);
-u32 ethtool_get_max_rxfh_channel(struct net_device *dev);
-int ethtool_get_max_rxnfc_channel(struct net_device *dev, u64 *max);
+int ethtool_check_max_channel(struct net_device *dev,
+                             struct ethtool_channels channels,
+                             struct genl_info *info);
 int __ethtool_get_ts_info(struct net_device *dev, struct kernel_ethtool_ts_info *info);
 
 extern const struct ethtool_phy_ops *ethtool_phy_ops;

diff --git a/net/ethtool/ioctl.c b/net/ethtool/ioctl.c
index e18823bf23306dffd32ddc752458e3c350a29b42..ba8630eb02efe214525b4a4de37704257bb62aa8 100644 (file)
--- a/net/ethtool/ioctl.c
+++ b/net/ethtool/ioctl.c
@@ -2069,8 +2069,6 @@ static noinline_for_stack int ethtool_set_channels(struct net_device *dev,
 {
        struct ethtool_channels channels, curr = { .cmd = ETHTOOL_GCHANNELS };
        u16 from_channel, to_channel;
-       u64 max_rxnfc_in_use;
-       u32 max_rxfh_in_use;
        unsigned int i;
        int ret;
 
@@ -2100,14 +2098,9 @@ static noinline_for_stack int ethtool_set_channels(struct net_device *dev,
            (!channels.rx_count || !channels.tx_count))
                return -EINVAL;
 
-       /* ensure the new Rx count fits within the configured Rx flow
-        * indirection table/rxnfc settings */
-       if (ethtool_get_max_rxnfc_channel(dev, &max_rxnfc_in_use))
-               max_rxnfc_in_use = 0;
-       max_rxfh_in_use = ethtool_get_max_rxfh_channel(dev);
-       if (channels.combined_count + channels.rx_count <=
-           max_t(u64, max_rxnfc_in_use, max_rxfh_in_use))
-               return -EINVAL;
+       ret = ethtool_check_max_channel(dev, channels, NULL);
+       if (ret)
+               return ret;
 
        /* Disabling channels, query zero-copy AF_XDP sockets */
        from_channel = channels.combined_count +