[RFC PATCH v3 net-next 0/7] ethtool: track custom RSS contexts in the core

[RFC PATCH v3 net-next 0/7] ethtool: track custom RSS contexts in the core

[edward.cree]

From: Edward Cree <ecree.xilinx@gmail.com>

Make the core responsible for tracking the set of custom RSS contexts,
 their IDs, indirection tables, hash keys, and hash functions; this
 lets us get rid of duplicative code in drivers, and will allow us to
 support netlink dumps later.

This series only moves the sfc EF10 & EF100 driver over to the new API; if
 the design is approved of, I plan to post a follow-up series to convert the
 other drivers (mvpp2, octeontx2, mlx5, sfc/siena) and remove the legacy API.
However, I don't have hardware for the drivers besides sfc, so I won't be
 able to test those myself.  Maintainers of those drivers (on CC), your
 comments on the API design would be appreciated, in particular whether the
 rss_ctx_max_id limit (corresponding to your fixed-size arrays of contexts)
 is actually needed.

Changes in v3:
* Added WangXun ngbe to patch #1, not sure if they've added WoL support since
  v2 or if I just missed it last time around
* Re-ordered struct ethtool_netdev_state to avoid hole (Andrew Lunn)
* Fixed some resource leaks in error handling paths (kuba)
* Added maintainers of other context-using drivers to CC

Edward Cree (7):
  net: move ethtool-related netdev state into its own struct
  net: ethtool: attach an IDR of custom RSS contexts to a netdevice
  net: ethtool: record custom RSS contexts in the IDR
  net: ethtool: let the core choose RSS context IDs
  net: ethtool: add an extack parameter to new rxfh_context APIs
  net: ethtool: add a mutex protecting RSS contexts
  sfc: use new rxfh_context API

 drivers/net/ethernet/realtek/r8169_main.c     |   4 +-
 drivers/net/ethernet/sfc/ef10.c               |   2 +-
 drivers/net/ethernet/sfc/ef100_ethtool.c      |   5 +-
 drivers/net/ethernet/sfc/efx.c                |   2 +-
 drivers/net/ethernet/sfc/efx.h                |   2 +-
 drivers/net/ethernet/sfc/efx_common.c         |  10 +-
 drivers/net/ethernet/sfc/ethtool.c            |   5 +-
 drivers/net/ethernet/sfc/ethtool_common.c     | 147 ++++++++++--------
 drivers/net/ethernet/sfc/ethtool_common.h     |  18 ++-
 drivers/net/ethernet/sfc/mcdi_filters.c       | 133 ++++++++--------
 drivers/net/ethernet/sfc/mcdi_filters.h       |   8 +-
 drivers/net/ethernet/sfc/net_driver.h         |  28 ++--
 drivers/net/ethernet/sfc/rx_common.c          |  64 ++------
 drivers/net/ethernet/sfc/rx_common.h          |   8 +-
 .../net/ethernet/wangxun/ngbe/ngbe_ethtool.c  |   4 +-
 drivers/net/ethernet/wangxun/ngbe/ngbe_main.c |   2 +-
 drivers/net/phy/phy.c                         |   2 +-
 drivers/net/phy/phy_device.c                  |   5 +-
 drivers/net/phy/phylink.c                     |   2 +-
 include/linux/ethtool.h                       | 109 ++++++++++++-
 include/linux/netdevice.h                     |   7 +-
 net/core/dev.c                                |  38 +++++
 net/ethtool/ioctl.c                           | 127 ++++++++++++++-
 net/ethtool/wol.c                             |   2 +-
 24 files changed, 491 insertions(+), 243 deletions(-)

[RFC PATCH v3 net-next 1/7] net: move ethtool-related netdev state into its own struct

[edward.cree]

From: Edward Cree <ecree.xilinx@gmail.com>

net_dev->ethtool is a pointer to new struct ethtool_netdev_state, which
 currently contains only the wol_enabled field.

Suggested-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Edward Cree <ecree.xilinx@gmail.com>
---
RealTek and WangXun maintainers, I only CCed you on this patch rather than
 the whole series, to avoid spamming you with a discussion that's likely
 not to be relevant to you.  Hope that's okay.

 drivers/net/ethernet/realtek/r8169_main.c        | 4 ++--
 drivers/net/ethernet/wangxun/ngbe/ngbe_ethtool.c | 4 ++--
 drivers/net/ethernet/wangxun/ngbe/ngbe_main.c    | 2 +-
 drivers/net/phy/phy.c                            | 2 +-
 drivers/net/phy/phy_device.c                     | 5 +++--
 drivers/net/phy/phylink.c                        | 2 +-
 include/linux/ethtool.h                          | 8 ++++++++
 include/linux/netdevice.h                        | 7 ++++---
 net/core/dev.c                                   | 4 ++++
 net/ethtool/ioctl.c                              | 2 +-
 net/ethtool/wol.c                                | 2 +-
 11 files changed, 28 insertions(+), 14 deletions(-)

diff --git a/drivers/net/ethernet/realtek/r8169_main.c b/drivers/net/ethernet/realtek/r8169_main.c
index 6351a2dc13bc..fe69416f2a93 100644
--- a/drivers/net/ethernet/realtek/r8169_main.c
+++ b/drivers/net/ethernet/realtek/r8169_main.c
@@ -1455,7 +1455,7 @@ static void __rtl8169_set_wol(struct rtl8169_private *tp, u32 wolopts)
 
 	if (tp->dash_type == RTL_DASH_NONE) {
 		rtl_set_d3_pll_down(tp, !wolopts);
-		tp->dev->wol_enabled = wolopts ? 1 : 0;
+		tp->dev->ethtool->wol_enabled = wolopts ? 1 : 0;
 	}
 }
 
@@ -5321,7 +5321,7 @@ static int rtl_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 		rtl_set_d3_pll_down(tp, true);
 	} else {
 		rtl_set_d3_pll_down(tp, false);
-		dev->wol_enabled = 1;
+		dev->ethtool->wol_enabled = 1;
 	}
 
 	jumbo_max = rtl_jumbo_max(tp);
diff --git a/drivers/net/ethernet/wangxun/ngbe/ngbe_ethtool.c b/drivers/net/ethernet/wangxun/ngbe/ngbe_ethtool.c
index ec0e869e9aac..091ee3d3e74d 100644
--- a/drivers/net/ethernet/wangxun/ngbe/ngbe_ethtool.c
+++ b/drivers/net/ethernet/wangxun/ngbe/ngbe_ethtool.c
@@ -34,9 +34,9 @@ static int ngbe_set_wol(struct net_device *netdev,
 	wx->wol = 0;
 	if (wol->wolopts & WAKE_MAGIC)
 		wx->wol = WX_PSR_WKUP_CTL_MAG;
-	netdev->wol_enabled = !!(wx->wol);
+	netdev->ethtool->wol_enabled = !!(wx->wol);
 	wr32(wx, WX_PSR_WKUP_CTL, wx->wol);
-	device_set_wakeup_enable(&pdev->dev, netdev->wol_enabled);
+	device_set_wakeup_enable(&pdev->dev, netdev->ethtool->wol_enabled);
 
 	return 0;
 }
diff --git a/drivers/net/ethernet/wangxun/ngbe/ngbe_main.c b/drivers/net/ethernet/wangxun/ngbe/ngbe_main.c
index 2b431db6085a..6752f8d04d9c 100644
--- a/drivers/net/ethernet/wangxun/ngbe/ngbe_main.c
+++ b/drivers/net/ethernet/wangxun/ngbe/ngbe_main.c
@@ -636,7 +636,7 @@ static int ngbe_probe(struct pci_dev *pdev,
 	if (wx->wol_hw_supported)
 		wx->wol = NGBE_PSR_WKUP_CTL_MAG;
 
-	netdev->wol_enabled = !!(wx->wol);
+	netdev->ethtool->wol_enabled = !!(wx->wol);
 	wr32(wx, NGBE_PSR_WKUP_CTL, wx->wol);
 	device_set_wakeup_enable(&pdev->dev, wx->wol);
 
diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c
index df54c137c5f5..6eeec338dfbf 100644
--- a/drivers/net/phy/phy.c
+++ b/drivers/net/phy/phy.c
@@ -1283,7 +1283,7 @@ static irqreturn_t phy_interrupt(int irq, void *phy_dat)
 		if (netdev) {
 			struct device *parent = netdev->dev.parent;
 
-			if (netdev->wol_enabled)
+			if (netdev->ethtool->wol_enabled)
 				pm_system_wakeup();
 			else if (device_may_wakeup(&netdev->dev))
 				pm_wakeup_dev_event(&netdev->dev, 0, true);
diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
index 2ce74593d6e4..62afc0424fbd 100644
--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c
@@ -285,7 +285,7 @@ static bool mdio_bus_phy_may_suspend(struct phy_device *phydev)
 	if (!netdev)
 		goto out;
 
-	if (netdev->wol_enabled)
+	if (netdev->ethtool->wol_enabled)
 		return false;
 
 	/* As long as not all affected network drivers support the
@@ -1859,7 +1859,8 @@ int phy_suspend(struct phy_device *phydev)
 		return 0;
 
 	phy_ethtool_get_wol(phydev, &wol);
-	phydev->wol_enabled = wol.wolopts || (netdev && netdev->wol_enabled);
+	phydev->wol_enabled = wol.wolopts ||
+			      (netdev && netdev->ethtool->wol_enabled);
 	/* If the device has WOL enabled, we cannot suspend the PHY */
 	if (phydev->wol_enabled && !(phydrv->flags & PHY_ALWAYS_CALL_SUSPEND))
 		return -EBUSY;
diff --git a/drivers/net/phy/phylink.c b/drivers/net/phy/phylink.c
index 0d7354955d62..b808ba1197c3 100644
--- a/drivers/net/phy/phylink.c
+++ b/drivers/net/phy/phylink.c
@@ -2172,7 +2172,7 @@ void phylink_suspend(struct phylink *pl, bool mac_wol)
 {
 	ASSERT_RTNL();
 
-	if (mac_wol && (!pl->netdev || pl->netdev->wol_enabled)) {
+	if (mac_wol && (!pl->netdev || pl->netdev->ethtool->wol_enabled)) {
 		/* Wake-on-Lan enabled, MAC handling */
 		mutex_lock(&pl->state_mutex);
 
diff --git a/include/linux/ethtool.h b/include/linux/ethtool.h
index 62b61527bcc4..8aeefc0b4e10 100644
--- a/include/linux/ethtool.h
+++ b/include/linux/ethtool.h
@@ -935,6 +935,14 @@ int ethtool_virtdev_set_link_ksettings(struct net_device *dev,
 				       const struct ethtool_link_ksettings *cmd,
 				       u32 *dev_speed, u8 *dev_duplex);
 
+/**
+ * struct ethtool_netdev_state - per-netdevice state for ethtool features
+ * @wol_enabled:	Wake-on-LAN is enabled
+ */
+struct ethtool_netdev_state {
+	unsigned		wol_enabled:1;
+};
+
 struct phy_device;
 struct phy_tdr_config;
 struct phy_plca_cfg;
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 0896aaa91dd7..efedfac436ad 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -79,6 +79,7 @@ struct xdp_buff;
 struct xdp_frame;
 struct xdp_metadata_ops;
 struct xdp_md;
+struct ethtool_netdev_state;
 
 typedef u32 xdp_features_t;
 
@@ -2011,8 +2012,6 @@ enum netdev_ml_priv_type {
  *			switch driver and used to set the phys state of the
  *			switch port.
  *
- *	@wol_enabled:	Wake-on-LAN is enabled
- *
  *	@threaded:	napi threaded mode is enabled
  *
  *	@net_notifier_list:	List of per-net netdev notifier block
@@ -2024,6 +2023,7 @@ enum netdev_ml_priv_type {
  *	@udp_tunnel_nic_info:	static structure describing the UDP tunnel
  *				offload capabilities of the device
  *	@udp_tunnel_nic:	UDP tunnel offload state
+ *	@ethtool:	ethtool related state
  *	@xdp_state:		stores info on attached XDP BPF programs
  *
  *	@nested_level:	Used as a parameter of spin_lock_nested() of
@@ -2383,7 +2383,6 @@ struct net_device {
 	struct sfp_bus		*sfp_bus;
 	struct lock_class_key	*qdisc_tx_busylock;
 	bool			proto_down;
-	unsigned		wol_enabled:1;
 	unsigned		threaded:1;
 
 	struct list_head	net_notifier_list;
@@ -2395,6 +2394,8 @@ struct net_device {
 	const struct udp_tunnel_nic_info	*udp_tunnel_nic_info;
 	struct udp_tunnel_nic	*udp_tunnel_nic;
 
+	struct ethtool_netdev_state *ethtool;
+
 	/* protected by rtnl_lock */
 	struct bpf_xdp_entity	xdp_state[__MAX_XDP_MODE];
 
diff --git a/net/core/dev.c b/net/core/dev.c
index ccff2b6ef958..bb3841371349 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -10747,6 +10747,9 @@ struct net_device *alloc_netdev_mqs(int sizeof_priv, const char *name,
 	dev->real_num_rx_queues = rxqs;
 	if (netif_alloc_rx_queues(dev))
 		goto free_all;
+	dev->ethtool = kzalloc(sizeof(*dev->ethtool), GFP_KERNEL_ACCOUNT);
+	if (!dev->ethtool)
+		goto free_all;
 
 	strcpy(dev->name, name);
 	dev->name_assign_type = name_assign_type;
@@ -10797,6 +10800,7 @@ void free_netdev(struct net_device *dev)
 		return;
 	}
 
+	kfree(dev->ethtool);
 	netif_free_tx_queues(dev);
 	netif_free_rx_queues(dev);
 
diff --git a/net/ethtool/ioctl.c b/net/ethtool/ioctl.c
index 0b0ce4f81c01..de78b24fffc9 100644
--- a/net/ethtool/ioctl.c
+++ b/net/ethtool/ioctl.c
@@ -1461,7 +1461,7 @@ static int ethtool_set_wol(struct net_device *dev, char __user *useraddr)
 	if (ret)
 		return ret;
 
-	dev->wol_enabled = !!wol.wolopts;
+	dev->ethtool->wol_enabled = !!wol.wolopts;
 	ethtool_notify(dev, ETHTOOL_MSG_WOL_NTF, NULL);
 
 	return 0;
diff --git a/net/ethtool/wol.c b/net/ethtool/wol.c
index 0ed56c9ac1bc..a39d8000d808 100644
--- a/net/ethtool/wol.c
+++ b/net/ethtool/wol.c
@@ -137,7 +137,7 @@ ethnl_set_wol(struct ethnl_req_info *req_info, struct genl_info *info)
 	ret = dev->ethtool_ops->set_wol(dev, &wol);
 	if (ret)
 		return ret;
-	dev->wol_enabled = !!wol.wolopts;
+	dev->ethtool->wol_enabled = !!wol.wolopts;
 	return 1;
 }
 

[RFC PATCH v3 net-next 2/7] net: ethtool: attach an IDR of custom RSS contexts to a netdevice

[edward.cree]

From: Edward Cree <ecree.xilinx@gmail.com>

Each context stores the RXFH settings (indir, key, and hfunc) as well
 as optionally some driver private data.
Delete any still-existing contexts at netdev unregister time.

Signed-off-by: Edward Cree <ecree.xilinx@gmail.com>
---
 include/linux/ethtool.h | 43 ++++++++++++++++++++++++++++++++++++++++-
 net/core/dev.c          | 23 ++++++++++++++++++++++
 2 files changed, 65 insertions(+), 1 deletion(-)

diff --git a/include/linux/ethtool.h b/include/linux/ethtool.h
index 8aeefc0b4e10..c770e32d79e6 100644
--- a/include/linux/ethtool.h
+++ b/include/linux/ethtool.h
@@ -157,6 +157,43 @@ static inline u32 ethtool_rxfh_indir_default(u32 index, u32 n_rx_rings)
 	return index % n_rx_rings;
 }
 
+/**
+ * struct ethtool_rxfh_context - a custom RSS context configuration
+ * @indir_size: Number of u32 entries in indirection table
+ * @key_size: Size of hash key, in bytes
+ * @hfunc: RSS hash function identifier.  One of the %ETH_RSS_HASH_*
+ * @priv_size: Size of driver private data, in bytes
+ * @indir_no_change: indir was not specified at create time
+ * @key_no_change: hkey was not specified at create time
+ */
+struct ethtool_rxfh_context {
+	u32 indir_size;
+	u32 key_size;
+	u8 hfunc;
+	u16 priv_size;
+	u8 indir_no_change:1;
+	u8 key_no_change:1;
+	/* private: driver private data, indirection table, and hash key are
+	 * stored sequentially in @data area.  Use below helpers to access.
+	 */
+	u8 data[] __aligned(sizeof(void *));
+};
+
+static inline void *ethtool_rxfh_context_priv(struct ethtool_rxfh_context *ctx)
+{
+	return ctx->data;
+}
+
+static inline u32 *ethtool_rxfh_context_indir(struct ethtool_rxfh_context *ctx)
+{
+	return (u32 *)(ctx->data + ALIGN(ctx->priv_size, sizeof(u32)));
+}
+
+static inline u8 *ethtool_rxfh_context_key(struct ethtool_rxfh_context *ctx)
+{
+	return (u8 *)(ethtool_rxfh_context_indir(ctx) + ctx->indir_size);
+}
+
 /* declare a link mode bitmap */
 #define __ETHTOOL_DECLARE_LINK_MODE_MASK(name)		\
 	DECLARE_BITMAP(name, __ETHTOOL_LINK_MODE_MASK_NBITS)
@@ -937,10 +974,14 @@ int ethtool_virtdev_set_link_ksettings(struct net_device *dev,
 
 /**
  * struct ethtool_netdev_state - per-netdevice state for ethtool features
+ * @rss_ctx:		IDR storing custom RSS context state
+ * @rss_ctx_max_id:	maximum (exclusive) supported RSS context ID
  * @wol_enabled:	Wake-on-LAN is enabled
  */
 struct ethtool_netdev_state {
-	unsigned		wol_enabled:1;
+	struct idr		rss_ctx;
+	u32			rss_ctx_max_id;
+	u32			wol_enabled:1;
 };
 
 struct phy_device;
diff --git a/net/core/dev.c b/net/core/dev.c
index bb3841371349..4bbb6bda7b7e 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -10050,6 +10050,9 @@ int register_netdevice(struct net_device *dev)
 	if (ret)
 		return ret;
 
+	/* rss ctx ID 0 is reserved for the default context, start from 1 */
+	idr_init_base(&dev->ethtool->rss_ctx, 1);
+
 	spin_lock_init(&dev->addr_list_lock);
 	netdev_set_addr_lockdep_class(dev);
 
@@ -10852,6 +10855,24 @@ void synchronize_net(void)
 }
 EXPORT_SYMBOL(synchronize_net);
 
+static void netdev_rss_contexts_free(struct net_device *dev)
+{
+	struct ethtool_rxfh_context *ctx;
+	u32 context;
+
+	if (!dev->ethtool_ops->set_rxfh_context)
+		return;
+	idr_for_each_entry(&dev->ethtool->rss_ctx, ctx, context) {
+		u32 *indir = ethtool_rxfh_context_indir(ctx);
+		u8 *key = ethtool_rxfh_context_key(ctx);
+
+		idr_remove(&dev->ethtool->rss_ctx, context);
+		dev->ethtool_ops->set_rxfh_context(dev, indir, key, ctx->hfunc,
+						   &context, true);
+		kfree(ctx);
+	}
+}
+
 /**
  *	unregister_netdevice_queue - remove device from the kernel
  *	@dev: device
@@ -10956,6 +10977,8 @@ void unregister_netdevice_many_notify(struct list_head *head,
 		netdev_name_node_alt_flush(dev);
 		netdev_name_node_free(dev->name_node);
 
+		netdev_rss_contexts_free(dev);
+
 		call_netdevice_notifiers(NETDEV_PRE_UNINIT, dev);
 
 		if (dev->netdev_ops->ndo_uninit)

[RFC PATCH v3 net-next 3/7] net: ethtool: record custom RSS contexts in the IDR

[edward.cree]

From: Edward Cree <ecree.xilinx@gmail.com>

Since drivers are still choosing the context IDs, we have to force the
 IDR to use the ID they've chosen rather than picking one ourselves.

Signed-off-by: Edward Cree <ecree.xilinx@gmail.com>
---
 include/linux/ethtool.h | 14 ++++++++
 net/ethtool/ioctl.c     | 71 +++++++++++++++++++++++++++++++++++++++--
 2 files changed, 83 insertions(+), 2 deletions(-)

diff --git a/include/linux/ethtool.h b/include/linux/ethtool.h
index c770e32d79e6..f7317b53ab61 100644
--- a/include/linux/ethtool.h
+++ b/include/linux/ethtool.h
@@ -194,6 +194,17 @@ static inline u8 *ethtool_rxfh_context_key(struct ethtool_rxfh_context *ctx)
 	return (u8 *)(ethtool_rxfh_context_indir(ctx) + ctx->indir_size);
 }
 
+static inline size_t ethtool_rxfh_context_size(u32 indir_size, u32 key_size,
+					       u16 priv_size)
+{
+	size_t indir_bytes = array_size(indir_size, sizeof(u32));
+	size_t flex_len;
+
+	flex_len = size_add(size_add(indir_bytes, key_size),
+			    ALIGN(priv_size, sizeof(u32)));
+	return struct_size((struct ethtool_rxfh_context *)0, data, flex_len);
+}
+
 /* declare a link mode bitmap */
 #define __ETHTOOL_DECLARE_LINK_MODE_MASK(name)		\
 	DECLARE_BITMAP(name, __ETHTOOL_LINK_MODE_MASK_NBITS)
@@ -731,6 +742,8 @@ struct ethtool_mm_stats {
  *	will remain unchanged.
  *	Returns a negative error code or zero. An error code must be returned
  *	if at least one unsupported change was requested.
+ * @rxfh_priv_size: size of the driver private data area the core should
+ *	allocate for an RSS context.
  * @get_rxfh_context: Get the contents of the RX flow hash indirection table,
  *	hash key, and/or hash function assiciated to the given rss context.
  *	Returns a negative error code or zero.
@@ -824,6 +837,7 @@ struct ethtool_ops {
 	u32     cap_link_lanes_supported:1;
 	u32	supported_coalesce_params;
 	u32	supported_ring_params;
+	u16	rxfh_priv_size;
 	void	(*get_drvinfo)(struct net_device *, struct ethtool_drvinfo *);
 	int	(*get_regs_len)(struct net_device *);
 	void	(*get_regs)(struct net_device *, struct ethtool_regs *, void *);
diff --git a/net/ethtool/ioctl.c b/net/ethtool/ioctl.c
index de78b24fffc9..db596b61c6ab 100644
--- a/net/ethtool/ioctl.c
+++ b/net/ethtool/ioctl.c
@@ -1249,6 +1249,7 @@ static noinline_for_stack int ethtool_set_rxfh(struct net_device *dev,
 {
 	int ret;
 	const struct ethtool_ops *ops = dev->ethtool_ops;
+	struct ethtool_rxfh_context *ctx = NULL;
 	struct ethtool_rxnfc rx_rings;
 	struct ethtool_rxfh rxfh;
 	u32 dev_indir_size = 0, dev_key_size = 0, i;
@@ -1256,7 +1257,7 @@ static noinline_for_stack int ethtool_set_rxfh(struct net_device *dev,
 	u8 *hkey = NULL;
 	u8 *rss_config;
 	u32 rss_cfg_offset = offsetof(struct ethtool_rxfh, rss_config[0]);
-	bool delete = false;
+	bool create = false, delete = false;
 
 	if (!ops->get_rxnfc || !ops->set_rxfh)
 		return -EOPNOTSUPP;
@@ -1275,6 +1276,7 @@ static noinline_for_stack int ethtool_set_rxfh(struct net_device *dev,
 	/* Most drivers don't handle rss_context, check it's 0 as well */
 	if (rxfh.rss_context && !ops->set_rxfh_context)
 		return -EOPNOTSUPP;
+	create = rxfh.rss_context == ETH_RXFH_CONTEXT_ALLOC;
 
 	/* If either indir, hash key or function is valid, proceed further.
 	 * Must request at least one change: indir size, hash key or function.
@@ -1332,13 +1334,42 @@ static noinline_for_stack int ethtool_set_rxfh(struct net_device *dev,
 		}
 	}
 
+	if (create) {
+		if (delete) {
+			ret = -EINVAL;
+			goto out;
+		}
+		ctx = kzalloc(ethtool_rxfh_context_size(dev_indir_size,
+							dev_key_size,
+							ops->rxfh_priv_size),
+			      GFP_KERNEL_ACCOUNT);
+		if (!ctx) {
+			ret = -ENOMEM;
+			goto out;
+		}
+		ctx->indir_size = dev_indir_size;
+		ctx->key_size = dev_key_size;
+		ctx->hfunc = rxfh.hfunc;
+		ctx->priv_size = ops->rxfh_priv_size;
+	} else if (rxfh.rss_context) {
+		ctx = idr_find(&dev->ethtool->rss_ctx, rxfh.rss_context);
+		if (!ctx) {
+			ret = -ENOENT;
+			goto out;
+		}
+	}
+
 	if (rxfh.rss_context)
 		ret = ops->set_rxfh_context(dev, indir, hkey, rxfh.hfunc,
 					    &rxfh.rss_context, delete);
 	else
 		ret = ops->set_rxfh(dev, indir, hkey, rxfh.hfunc);
-	if (ret)
+	if (ret) {
+		if (create)
+			/* failed to create, free our new tracking entry */
+			kfree(ctx);
 		goto out;
+	}
 
 	if (copy_to_user(useraddr + offsetof(struct ethtool_rxfh, rss_context),
 			 &rxfh.rss_context, sizeof(rxfh.rss_context)))
@@ -1351,6 +1382,42 @@ static noinline_for_stack int ethtool_set_rxfh(struct net_device *dev,
 		else if (rxfh.indir_size != ETH_RXFH_INDIR_NO_CHANGE)
 			dev->priv_flags |= IFF_RXFH_CONFIGURED;
 	}
+	/* Update rss_ctx tracking */
+	if (create) {
+		/* Ideally this should happen before calling the driver,
+		 * so that we can fail more cleanly; but we don't have the
+		 * context ID until the driver picks it, so we have to
+		 * wait until after.
+		 */
+		if (WARN_ON(idr_find(&dev->ethtool->rss_ctx, rxfh.rss_context))) {
+			/* context ID reused, our tracking is screwed */
+			kfree(ctx);
+			goto out;
+		}
+		/* Allocate the exact ID the driver gave us */
+		WARN_ON(idr_alloc(&dev->ethtool->rss_ctx, ctx, rxfh.rss_context,
+				  rxfh.rss_context + 1, GFP_KERNEL) !=
+			rxfh.rss_context);
+		ctx->indir_no_change = rxfh.indir_size == ETH_RXFH_INDIR_NO_CHANGE;
+		ctx->key_no_change = !rxfh.key_size;
+	}
+	if (delete) {
+		WARN_ON(idr_remove(&dev->ethtool->rss_ctx, rxfh.rss_context) != ctx);
+		kfree(ctx);
+	} else if (ctx) {
+		if (indir) {
+			for (i = 0; i < dev_indir_size; i++)
+				ethtool_rxfh_context_indir(ctx)[i] = indir[i];
+			ctx->indir_no_change = 0;
+		}
+		if (hkey) {
+			memcpy(ethtool_rxfh_context_key(ctx), hkey,
+			       dev_key_size);
+			ctx->key_no_change = 0;
+		}
+		if (rxfh.hfunc != ETH_RSS_HASH_NO_CHANGE)
+			ctx->hfunc = rxfh.hfunc;
+	}
 
 out:
 	kfree(rss_config);

[RFC PATCH v3 net-next 4/7] net: ethtool: let the core choose RSS context IDs

[edward.cree]

From: Edward Cree <ecree.xilinx@gmail.com>

Add a new API to create/modify/remove RSS contexts, that passes in the
 newly-chosen context ID (not as a pointer) rather than leaving the
 driver to choose it on create.  Also pass in the ctx, allowing drivers
 to easily use its private data area to store their hardware-specific
 state.
Keep the existing .set_rxfh_context API for now as a fallback, but
 deprecate it.

Signed-off-by: Edward Cree <ecree.xilinx@gmail.com>
---
 include/linux/ethtool.h | 40 ++++++++++++++++++++++++--
 net/core/dev.c          | 11 +++++--
 net/ethtool/ioctl.c     | 64 +++++++++++++++++++++++++++++++----------
 3 files changed, 94 insertions(+), 21 deletions(-)

diff --git a/include/linux/ethtool.h b/include/linux/ethtool.h
index f7317b53ab61..4fa2a7f6ed4c 100644
--- a/include/linux/ethtool.h
+++ b/include/linux/ethtool.h
@@ -747,10 +747,33 @@ struct ethtool_mm_stats {
  * @get_rxfh_context: Get the contents of the RX flow hash indirection table,
  *	hash key, and/or hash function assiciated to the given rss context.
  *	Returns a negative error code or zero.
- * @set_rxfh_context: Create, remove and configure RSS contexts. Allows setting
+ * @create_rxfh_context: Create a new RSS context with the specified RX flow
+ *	hash indirection table, hash key, and hash function.
+ *	Arguments which are set to %NULL or zero will be populated to
+ *	appropriate defaults by the driver.
+ *	The &struct ethtool_rxfh_context for this context is passed in @ctx;
+ *	note that the indir table, hkey and hfunc are not yet populated as
+ *	of this call.  The driver does not need to update these; the core
+ *	will do so if this op succeeds.
+ *	If the driver provides this method, it must also provide
+ *	@modify_rxfh_context and @remove_rxfh_context.
+ *	Returns a negative error code or zero.
+ * @modify_rxfh_context: Reconfigure the specified RSS context.  Allows setting
  *	the contents of the RX flow hash indirection table, hash key, and/or
- *	hash function associated to the given context. Arguments which are set
- *	to %NULL or zero will remain unchanged.
+ *	hash function associated with the given context.
+ *	Arguments which are set to %NULL or zero will remain unchanged.
+ *	The &struct ethtool_rxfh_context for this context is passed in @ctx;
+ *	note that it will still contain the *old* settings.  The driver does
+ *	not need to update these; the core will do so if this op succeeds.
+ *	Returns a negative error code or zero. An error code must be returned
+ *	if at least one unsupported change was requested.
+ * @remove_rxfh_context: Remove the specified RSS context.
+ *	The &struct ethtool_rxfh_context for this context is passed in @ctx.
+ *	Returns a negative error code or zero.
+ * @set_rxfh_context: Deprecated API to create, remove and configure RSS
+ *	contexts. Allows setting the contents of the RX flow hash indirection
+ *	table, hash key, and/or hash function associated to the given context.
+ *	Arguments which are set to %NULL or zero will remain unchanged.
  *	Returns a negative error code or zero. An error code must be returned
  *	if at least one unsupported change was requested.
  * @get_channels: Get number of channels.
@@ -901,6 +924,17 @@ struct ethtool_ops {
 			    const u8 *key, const u8 hfunc);
 	int	(*get_rxfh_context)(struct net_device *, u32 *indir, u8 *key,
 				    u8 *hfunc, u32 rss_context);
+	int	(*create_rxfh_context)(struct net_device *,
+				       struct ethtool_rxfh_context *ctx,
+				       const u32 *indir, const u8 *key,
+				       const u8 hfunc, u32 rss_context);
+	int	(*modify_rxfh_context)(struct net_device *,
+				       struct ethtool_rxfh_context *ctx,
+				       const u32 *indir, const u8 *key,
+				       const u8 hfunc, u32 rss_context);
+	int	(*remove_rxfh_context)(struct net_device *,
+				       struct ethtool_rxfh_context *ctx,
+				       u32 rss_context);
 	int	(*set_rxfh_context)(struct net_device *, const u32 *indir,
 				    const u8 *key, const u8 hfunc,
 				    u32 *rss_context, bool delete);
diff --git a/net/core/dev.c b/net/core/dev.c
index 4bbb6bda7b7e..6b8e5fd8691b 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -10860,15 +10860,20 @@ static void netdev_rss_contexts_free(struct net_device *dev)
 	struct ethtool_rxfh_context *ctx;
 	u32 context;
 
-	if (!dev->ethtool_ops->set_rxfh_context)
+	if (!dev->ethtool_ops->create_rxfh_context &&
+	    !dev->ethtool_ops->set_rxfh_context)
 		return;
 	idr_for_each_entry(&dev->ethtool->rss_ctx, ctx, context) {
 		u32 *indir = ethtool_rxfh_context_indir(ctx);
 		u8 *key = ethtool_rxfh_context_key(ctx);
 
 		idr_remove(&dev->ethtool->rss_ctx, context);
-		dev->ethtool_ops->set_rxfh_context(dev, indir, key, ctx->hfunc,
-						   &context, true);
+		if (dev->ethtool_ops->create_rxfh_context)
+			dev->ethtool_ops->remove_rxfh_context(dev, ctx, context);
+		else
+			dev->ethtool_ops->set_rxfh_context(dev, indir, key,
+							   ctx->hfunc,
+							   &context, true);
 		kfree(ctx);
 	}
 }
diff --git a/net/ethtool/ioctl.c b/net/ethtool/ioctl.c
index db596b61c6ab..4ce960a5ad4c 100644
--- a/net/ethtool/ioctl.c
+++ b/net/ethtool/ioctl.c
@@ -1274,7 +1274,8 @@ static noinline_for_stack int ethtool_set_rxfh(struct net_device *dev,
 	if (rxfh.rsvd8[0] || rxfh.rsvd8[1] || rxfh.rsvd8[2] || rxfh.rsvd32)
 		return -EINVAL;
 	/* Most drivers don't handle rss_context, check it's 0 as well */
-	if (rxfh.rss_context && !ops->set_rxfh_context)
+	if (rxfh.rss_context && !(ops->create_rxfh_context ||
+				  ops->set_rxfh_context))
 		return -EOPNOTSUPP;
 	create = rxfh.rss_context == ETH_RXFH_CONTEXT_ALLOC;
 
@@ -1349,8 +1350,28 @@ static noinline_for_stack int ethtool_set_rxfh(struct net_device *dev,
 		}
 		ctx->indir_size = dev_indir_size;
 		ctx->key_size = dev_key_size;
-		ctx->hfunc = rxfh.hfunc;
 		ctx->priv_size = ops->rxfh_priv_size;
+		/* Initialise to an empty context */
+		ctx->indir_no_change = ctx->key_no_change = 1;
+		ctx->hfunc = ETH_RSS_HASH_NO_CHANGE;
+		if (ops->create_rxfh_context) {
+			int ctx_id;
+
+			/* driver uses new API, core allocates ID */
+			/* if rss_ctx_max_id is not specified (left as 0), it is
+			 * treated as INT_MAX + 1 by idr_alloc
+			 */
+			ctx_id = idr_alloc(&dev->ethtool->rss_ctx, ctx, 1,
+					   dev->ethtool->rss_ctx_max_id,
+					   GFP_KERNEL_ACCOUNT);
+			/* 0 is not allowed, so treat it like an error here */
+			if (ctx_id <= 0) {
+				kfree(ctx);
+				ret = -ENOMEM;
+				goto out;
+			}
+			rxfh.rss_context = ctx_id;
+		}
 	} else if (rxfh.rss_context) {
 		ctx = idr_find(&dev->ethtool->rss_ctx, rxfh.rss_context);
 		if (!ctx) {
@@ -1359,15 +1380,34 @@ static noinline_for_stack int ethtool_set_rxfh(struct net_device *dev,
 		}
 	}
 
-	if (rxfh.rss_context)
-		ret = ops->set_rxfh_context(dev, indir, hkey, rxfh.hfunc,
-					    &rxfh.rss_context, delete);
-	else
+	if (rxfh.rss_context) {
+		if (ops->create_rxfh_context) {
+			if (create)
+				ret = ops->create_rxfh_context(dev, ctx, indir,
+							       hkey, rxfh.hfunc,
+							       rxfh.rss_context);
+			else if (delete)
+				ret = ops->remove_rxfh_context(dev, ctx,
+							       rxfh.rss_context);
+			else
+				ret = ops->modify_rxfh_context(dev, ctx, indir,
+							       hkey, rxfh.hfunc,
+							       rxfh.rss_context);
+		} else {
+			ret = ops->set_rxfh_context(dev, indir, hkey,
+						    rxfh.hfunc,
+						    &rxfh.rss_context, delete);
+		}
+	} else {
 		ret = ops->set_rxfh(dev, indir, hkey, rxfh.hfunc);
+	}
 	if (ret) {
-		if (create)
+		if (create) {
 			/* failed to create, free our new tracking entry */
+			if (ops->create_rxfh_context)
+				idr_remove(&dev->ethtool->rss_ctx, rxfh.rss_context);
 			kfree(ctx);
+		}
 		goto out;
 	}
 
@@ -1383,12 +1423,8 @@ static noinline_for_stack int ethtool_set_rxfh(struct net_device *dev,
 			dev->priv_flags |= IFF_RXFH_CONFIGURED;
 	}
 	/* Update rss_ctx tracking */
-	if (create) {
-		/* Ideally this should happen before calling the driver,
-		 * so that we can fail more cleanly; but we don't have the
-		 * context ID until the driver picks it, so we have to
-		 * wait until after.
-		 */
+	if (create && !ops->create_rxfh_context) {
+		/* driver uses old API, it chose context ID */
 		if (WARN_ON(idr_find(&dev->ethtool->rss_ctx, rxfh.rss_context))) {
 			/* context ID reused, our tracking is screwed */
 			kfree(ctx);
@@ -1398,8 +1434,6 @@ static noinline_for_stack int ethtool_set_rxfh(struct net_device *dev,
 		WARN_ON(idr_alloc(&dev->ethtool->rss_ctx, ctx, rxfh.rss_context,
 				  rxfh.rss_context + 1, GFP_KERNEL) !=
 			rxfh.rss_context);
-		ctx->indir_no_change = rxfh.indir_size == ETH_RXFH_INDIR_NO_CHANGE;
-		ctx->key_no_change = !rxfh.key_size;
 	}
 	if (delete) {
 		WARN_ON(idr_remove(&dev->ethtool->rss_ctx, rxfh.rss_context) != ctx);

[RFC PATCH v3 net-next 5/7] net: ethtool: add an extack parameter to new rxfh_context APIs

[edward.cree]

From: Edward Cree <ecree.xilinx@gmail.com>

Currently passed as NULL, but will allow drivers to report back errors
 when ethnl support for these ops is added.

Signed-off-by: Edward Cree <ecree.xilinx@gmail.com>
---
 include/linux/ethtool.h | 9 ++++++---
 net/core/dev.c          | 3 ++-
 net/ethtool/ioctl.c     | 9 ++++++---
 3 files changed, 14 insertions(+), 7 deletions(-)

diff --git a/include/linux/ethtool.h b/include/linux/ethtool.h
index 4fa2a7f6ed4c..8977aa8523e3 100644
--- a/include/linux/ethtool.h
+++ b/include/linux/ethtool.h
@@ -927,14 +927,17 @@ struct ethtool_ops {
 	int	(*create_rxfh_context)(struct net_device *,
 				       struct ethtool_rxfh_context *ctx,
 				       const u32 *indir, const u8 *key,
-				       const u8 hfunc, u32 rss_context);
+				       const u8 hfunc, u32 rss_context,
+				       struct netlink_ext_ack *extack);
 	int	(*modify_rxfh_context)(struct net_device *,
 				       struct ethtool_rxfh_context *ctx,
 				       const u32 *indir, const u8 *key,
-				       const u8 hfunc, u32 rss_context);
+				       const u8 hfunc, u32 rss_context,
+				       struct netlink_ext_ack *extack);
 	int	(*remove_rxfh_context)(struct net_device *,
 				       struct ethtool_rxfh_context *ctx,
-				       u32 rss_context);
+				       u32 rss_context,
+				       struct netlink_ext_ack *extack);
 	int	(*set_rxfh_context)(struct net_device *, const u32 *indir,
 				    const u8 *key, const u8 hfunc,
 				    u32 *rss_context, bool delete);
diff --git a/net/core/dev.c b/net/core/dev.c
index 6b8e5fd8691b..f12767466427 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -10869,7 +10869,8 @@ static void netdev_rss_contexts_free(struct net_device *dev)
 
 		idr_remove(&dev->ethtool->rss_ctx, context);
 		if (dev->ethtool_ops->create_rxfh_context)
-			dev->ethtool_ops->remove_rxfh_context(dev, ctx, context);
+			dev->ethtool_ops->remove_rxfh_context(dev, ctx, context,
+							      NULL);
 		else
 			dev->ethtool_ops->set_rxfh_context(dev, indir, key,
 							   ctx->hfunc,
diff --git a/net/ethtool/ioctl.c b/net/ethtool/ioctl.c
index 4ce960a5ad4c..5b943db75974 100644
--- a/net/ethtool/ioctl.c
+++ b/net/ethtool/ioctl.c
@@ -1385,14 +1385,17 @@ static noinline_for_stack int ethtool_set_rxfh(struct net_device *dev,
 			if (create)
 				ret = ops->create_rxfh_context(dev, ctx, indir,
 							       hkey, rxfh.hfunc,
-							       rxfh.rss_context);
+							       rxfh.rss_context,
+							       NULL);
 			else if (delete)
 				ret = ops->remove_rxfh_context(dev, ctx,
-							       rxfh.rss_context);
+							       rxfh.rss_context,
+							       NULL);
 			else
 				ret = ops->modify_rxfh_context(dev, ctx, indir,
 							       hkey, rxfh.hfunc,
-							       rxfh.rss_context);
+							       rxfh.rss_context,
+							       NULL);
 		} else {
 			ret = ops->set_rxfh_context(dev, indir, hkey,
 						    rxfh.hfunc,

[RFC PATCH v3 net-next 6/7] net: ethtool: add a mutex protecting RSS contexts

[edward.cree]

From: Edward Cree <ecree.xilinx@gmail.com>

While this is not needed to serialise the ethtool entry points (which
 are all under RTNL), drivers may have cause to asynchronously access
 dev->ethtool->rss_ctx; taking dev->ethtool->rss_lock allows them to
 do this safely without needing to take the RTNL.

Signed-off-by: Edward Cree <ecree.xilinx@gmail.com>
---
 include/linux/ethtool.h | 3 +++
 net/core/dev.c          | 5 +++++
 net/ethtool/ioctl.c     | 7 +++++++
 3 files changed, 15 insertions(+)

diff --git a/include/linux/ethtool.h b/include/linux/ethtool.h
index 8977aa8523e3..1f8293deebd5 100644
--- a/include/linux/ethtool.h
+++ b/include/linux/ethtool.h
@@ -1026,11 +1026,14 @@ int ethtool_virtdev_set_link_ksettings(struct net_device *dev,
 /**
  * struct ethtool_netdev_state - per-netdevice state for ethtool features
  * @rss_ctx:		IDR storing custom RSS context state
+ * @rss_lock:		Protects entries in @rss_ctx.  May be taken from
+ *			within RTNL.
  * @rss_ctx_max_id:	maximum (exclusive) supported RSS context ID
  * @wol_enabled:	Wake-on-LAN is enabled
  */
 struct ethtool_netdev_state {
 	struct idr		rss_ctx;
+	struct mutex		rss_lock;
 	u32			rss_ctx_max_id;
 	u32			wol_enabled:1;
 };
diff --git a/net/core/dev.c b/net/core/dev.c
index f12767466427..2acb4d8cd4c7 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -10054,6 +10054,7 @@ int register_netdevice(struct net_device *dev)
 	idr_init_base(&dev->ethtool->rss_ctx, 1);
 
 	spin_lock_init(&dev->addr_list_lock);
+	mutex_init(&dev->ethtool->rss_lock);
 	netdev_set_addr_lockdep_class(dev);
 
 	ret = dev_get_valid_name(net, dev, dev->name);
@@ -10863,6 +10864,7 @@ static void netdev_rss_contexts_free(struct net_device *dev)
 	if (!dev->ethtool_ops->create_rxfh_context &&
 	    !dev->ethtool_ops->set_rxfh_context)
 		return;
+	mutex_lock(&dev->ethtool->rss_lock);
 	idr_for_each_entry(&dev->ethtool->rss_ctx, ctx, context) {
 		u32 *indir = ethtool_rxfh_context_indir(ctx);
 		u8 *key = ethtool_rxfh_context_key(ctx);
@@ -10877,6 +10879,7 @@ static void netdev_rss_contexts_free(struct net_device *dev)
 							   &context, true);
 		kfree(ctx);
 	}
+	mutex_unlock(&dev->ethtool->rss_lock);
 }
 
 /**
@@ -10990,6 +10993,8 @@ void unregister_netdevice_many_notify(struct list_head *head,
 		if (dev->netdev_ops->ndo_uninit)
 			dev->netdev_ops->ndo_uninit(dev);
 
+		mutex_destroy(&dev->ethtool->rss_lock);
+
 		if (skb)
 			rtmsg_ifinfo_send(skb, dev, GFP_KERNEL, portid, nlh);
 
diff --git a/net/ethtool/ioctl.c b/net/ethtool/ioctl.c
index 5b943db75974..70cca80cea70 100644
--- a/net/ethtool/ioctl.c
+++ b/net/ethtool/ioctl.c
@@ -1258,6 +1258,7 @@ static noinline_for_stack int ethtool_set_rxfh(struct net_device *dev,
 	u8 *rss_config;
 	u32 rss_cfg_offset = offsetof(struct ethtool_rxfh, rss_config[0]);
 	bool create = false, delete = false;
+	bool locked = false; /* dev->ethtool->rss_lock taken */
 
 	if (!ops->get_rxnfc || !ops->set_rxfh)
 		return -EOPNOTSUPP;
@@ -1335,6 +1336,10 @@ static noinline_for_stack int ethtool_set_rxfh(struct net_device *dev,
 		}
 	}
 
+	if (rxfh.rss_context) {
+		mutex_lock(&dev->ethtool->rss_lock);
+		locked = true;
+	}
 	if (create) {
 		if (delete) {
 			ret = -EINVAL;
@@ -1457,6 +1462,8 @@ static noinline_for_stack int ethtool_set_rxfh(struct net_device *dev,
 	}
 
 out:
+	if (locked)
+		mutex_unlock(&dev->ethtool->rss_lock);
 	kfree(rss_config);
 	return ret;
 }

[RFC PATCH v3 net-next 7/7] sfc: use new rxfh_context API

[edward.cree]

From: Edward Cree <ecree.xilinx@gmail.com>

The core is now responsible for allocating IDs and a memory region for
 us to store our state (struct efx_rss_context_priv), so we no longer
 need efx_alloc_rss_context_entry() and friends.
Since the contexts are now maintained by the core, use the core's lock
 (net_dev->ethtool->rss_lock), rather than our own mutex (efx->rss_lock),
 to serialise access against changes; and remove the now-unused
 efx->rss_lock from struct efx_nic.

Signed-off-by: Edward Cree <ecree.xilinx@gmail.com>
---
 drivers/net/ethernet/sfc/ef10.c           |   2 +-
 drivers/net/ethernet/sfc/ef100_ethtool.c  |   5 +-
 drivers/net/ethernet/sfc/efx.c            |   2 +-
 drivers/net/ethernet/sfc/efx.h            |   2 +-
 drivers/net/ethernet/sfc/efx_common.c     |  10 +-
 drivers/net/ethernet/sfc/ethtool.c        |   5 +-
 drivers/net/ethernet/sfc/ethtool_common.c | 147 +++++++++++++---------
 drivers/net/ethernet/sfc/ethtool_common.h |  18 ++-
 drivers/net/ethernet/sfc/mcdi_filters.c   | 133 ++++++++++----------
 drivers/net/ethernet/sfc/mcdi_filters.h   |   8 +-
 drivers/net/ethernet/sfc/net_driver.h     |  28 ++---
 drivers/net/ethernet/sfc/rx_common.c      |  64 ++--------
 drivers/net/ethernet/sfc/rx_common.h      |   8 +-
 13 files changed, 213 insertions(+), 219 deletions(-)

diff --git a/drivers/net/ethernet/sfc/ef10.c b/drivers/net/ethernet/sfc/ef10.c
index 6dfa062feebc..e20305461b57 100644
--- a/drivers/net/ethernet/sfc/ef10.c
+++ b/drivers/net/ethernet/sfc/ef10.c
@@ -1396,7 +1396,7 @@ static void efx_ef10_table_reset_mc_allocations(struct efx_nic *efx)
 	efx_mcdi_filter_table_reset_mc_allocations(efx);
 	nic_data->must_restore_piobufs = true;
 	efx_ef10_forget_old_piobufs(efx);
-	efx->rss_context.context_id = EFX_MCDI_RSS_CONTEXT_INVALID;
+	efx->rss_context.priv.context_id = EFX_MCDI_RSS_CONTEXT_INVALID;
 
 	/* Driver-created vswitches and vports must be re-created */
 	nic_data->must_probe_vswitching = true;
diff --git a/drivers/net/ethernet/sfc/ef100_ethtool.c b/drivers/net/ethernet/sfc/ef100_ethtool.c
index 702abbe59b76..c5f82eb0e5b4 100644
--- a/drivers/net/ethernet/sfc/ef100_ethtool.c
+++ b/drivers/net/ethernet/sfc/ef100_ethtool.c
@@ -58,10 +58,13 @@ const struct ethtool_ops ef100_ethtool_ops = {
 
 	.get_rxfh_indir_size	= efx_ethtool_get_rxfh_indir_size,
 	.get_rxfh_key_size	= efx_ethtool_get_rxfh_key_size,
+	.rxfh_priv_size		= sizeof(struct efx_rss_context_priv),
 	.get_rxfh		= efx_ethtool_get_rxfh,
 	.set_rxfh		= efx_ethtool_set_rxfh,
 	.get_rxfh_context	= efx_ethtool_get_rxfh_context,
-	.set_rxfh_context	= efx_ethtool_set_rxfh_context,
+	.create_rxfh_context	= efx_ethtool_create_rxfh_context,
+	.modify_rxfh_context	= efx_ethtool_modify_rxfh_context,
+	.remove_rxfh_context	= efx_ethtool_remove_rxfh_context,
 
 	.get_module_info	= efx_ethtool_get_module_info,
 	.get_module_eeprom	= efx_ethtool_get_module_eeprom,
diff --git a/drivers/net/ethernet/sfc/efx.c b/drivers/net/ethernet/sfc/efx.c
index 19f4b4d0b851..6ae84356797f 100644
--- a/drivers/net/ethernet/sfc/efx.c
+++ b/drivers/net/ethernet/sfc/efx.c
@@ -299,7 +299,7 @@ static int efx_probe_nic(struct efx_nic *efx)
 	if (efx->n_channels > 1)
 		netdev_rss_key_fill(efx->rss_context.rx_hash_key,
 				    sizeof(efx->rss_context.rx_hash_key));
-	efx_set_default_rx_indir_table(efx, &efx->rss_context);
+	efx_set_default_rx_indir_table(efx, efx->rss_context.rx_indir_table);
 
 	/* Initialise the interrupt moderation settings */
 	efx->irq_mod_step_us = DIV_ROUND_UP(efx->timer_quantum_ns, 1000);
diff --git a/drivers/net/ethernet/sfc/efx.h b/drivers/net/ethernet/sfc/efx.h
index 48d3623735ba..7a6cab883d66 100644
--- a/drivers/net/ethernet/sfc/efx.h
+++ b/drivers/net/ethernet/sfc/efx.h
@@ -158,7 +158,7 @@ static inline s32 efx_filter_get_rx_ids(struct efx_nic *efx,
 }
 
 /* RSS contexts */
-static inline bool efx_rss_active(struct efx_rss_context *ctx)
+static inline bool efx_rss_active(struct efx_rss_context_priv *ctx)
 {
 	return ctx->context_id != EFX_MCDI_RSS_CONTEXT_INVALID;
 }
diff --git a/drivers/net/ethernet/sfc/efx_common.c b/drivers/net/ethernet/sfc/efx_common.c
index 175bd9cdfdac..2cd92e1f68db 100644
--- a/drivers/net/ethernet/sfc/efx_common.c
+++ b/drivers/net/ethernet/sfc/efx_common.c
@@ -714,7 +714,7 @@ void efx_reset_down(struct efx_nic *efx, enum reset_type method)
 
 	mutex_lock(&efx->mac_lock);
 	down_write(&efx->filter_sem);
-	mutex_lock(&efx->rss_lock);
+	mutex_lock(&efx->net_dev->ethtool->rss_lock);
 	efx->type->fini(efx);
 }
 
@@ -777,7 +777,7 @@ int efx_reset_up(struct efx_nic *efx, enum reset_type method, bool ok)
 
 	if (efx->type->rx_restore_rss_contexts)
 		efx->type->rx_restore_rss_contexts(efx);
-	mutex_unlock(&efx->rss_lock);
+	mutex_unlock(&efx->net_dev->ethtool->rss_lock);
 	efx->type->filter_table_restore(efx);
 	up_write(&efx->filter_sem);
 
@@ -793,7 +793,7 @@ int efx_reset_up(struct efx_nic *efx, enum reset_type method, bool ok)
 fail:
 	efx->port_initialized = false;
 
-	mutex_unlock(&efx->rss_lock);
+	mutex_unlock(&efx->net_dev->ethtool->rss_lock);
 	up_write(&efx->filter_sem);
 	mutex_unlock(&efx->mac_lock);
 
@@ -1000,9 +1000,7 @@ int efx_init_struct(struct efx_nic *efx, struct pci_dev *pci_dev)
 		efx->type->rx_hash_offset - efx->type->rx_prefix_size;
 	efx->rx_packet_ts_offset =
 		efx->type->rx_ts_offset - efx->type->rx_prefix_size;
-	INIT_LIST_HEAD(&efx->rss_context.list);
-	efx->rss_context.context_id = EFX_MCDI_RSS_CONTEXT_INVALID;
-	mutex_init(&efx->rss_lock);
+	efx->rss_context.priv.context_id = EFX_MCDI_RSS_CONTEXT_INVALID;
 	efx->vport_id = EVB_PORT_ID_ASSIGNED;
 	spin_lock_init(&efx->stats_lock);
 	efx->vi_stride = EFX_DEFAULT_VI_STRIDE;
diff --git a/drivers/net/ethernet/sfc/ethtool.c b/drivers/net/ethernet/sfc/ethtool.c
index 364323599f7b..f5fb7464e025 100644
--- a/drivers/net/ethernet/sfc/ethtool.c
+++ b/drivers/net/ethernet/sfc/ethtool.c
@@ -267,10 +267,13 @@ const struct ethtool_ops efx_ethtool_ops = {
 	.set_rxnfc		= efx_ethtool_set_rxnfc,
 	.get_rxfh_indir_size	= efx_ethtool_get_rxfh_indir_size,
 	.get_rxfh_key_size	= efx_ethtool_get_rxfh_key_size,
+	.rxfh_priv_size		= sizeof(struct efx_rss_context_priv),
 	.get_rxfh		= efx_ethtool_get_rxfh,
 	.set_rxfh		= efx_ethtool_set_rxfh,
 	.get_rxfh_context	= efx_ethtool_get_rxfh_context,
-	.set_rxfh_context	= efx_ethtool_set_rxfh_context,
+	.create_rxfh_context	= efx_ethtool_create_rxfh_context,
+	.modify_rxfh_context	= efx_ethtool_modify_rxfh_context,
+	.remove_rxfh_context	= efx_ethtool_remove_rxfh_context,
 	.get_ts_info		= efx_ethtool_get_ts_info,
 	.get_module_info	= efx_ethtool_get_module_info,
 	.get_module_eeprom	= efx_ethtool_get_module_eeprom,
diff --git a/drivers/net/ethernet/sfc/ethtool_common.c b/drivers/net/ethernet/sfc/ethtool_common.c
index a8cbceeb301b..7cd01012152e 100644
--- a/drivers/net/ethernet/sfc/ethtool_common.c
+++ b/drivers/net/ethernet/sfc/ethtool_common.c
@@ -820,10 +820,10 @@ int efx_ethtool_get_rxnfc(struct net_device *net_dev,
 		return 0;
 
 	case ETHTOOL_GRXFH: {
-		struct efx_rss_context *ctx = &efx->rss_context;
+		struct efx_rss_context_priv *ctx = &efx->rss_context.priv;
 		__u64 data;
 
-		mutex_lock(&efx->rss_lock);
+		mutex_lock(&net_dev->ethtool->rss_lock);
 		if (info->flow_type & FLOW_RSS && info->rss_context) {
 			ctx = efx_find_rss_context_entry(efx, info->rss_context);
 			if (!ctx) {
@@ -864,7 +864,7 @@ int efx_ethtool_get_rxnfc(struct net_device *net_dev,
 out_setdata_unlock:
 		info->data = data;
 out_unlock:
-		mutex_unlock(&efx->rss_lock);
+		mutex_unlock(&net_dev->ethtool->rss_lock);
 		return rc;
 	}
 
@@ -1207,96 +1207,121 @@ int efx_ethtool_get_rxfh_context(struct net_device *net_dev, u32 *indir,
 				 u8 *key, u8 *hfunc, u32 rss_context)
 {
 	struct efx_nic *efx = efx_netdev_priv(net_dev);
-	struct efx_rss_context *ctx;
+	struct efx_rss_context_priv *ctx_priv;
+	struct efx_rss_context ctx;
 	int rc = 0;
 
 	if (!efx->type->rx_pull_rss_context_config)
 		return -EOPNOTSUPP;
 
-	mutex_lock(&efx->rss_lock);
-	ctx = efx_find_rss_context_entry(efx, rss_context);
-	if (!ctx) {
+	mutex_lock(&net_dev->ethtool->rss_lock);
+	ctx_priv = efx_find_rss_context_entry(efx, rss_context);
+	if (!ctx_priv) {
 		rc = -ENOENT;
 		goto out_unlock;
 	}
-	rc = efx->type->rx_pull_rss_context_config(efx, ctx);
+	ctx.priv = *ctx_priv;
+	rc = efx->type->rx_pull_rss_context_config(efx, &ctx);
 	if (rc)
 		goto out_unlock;
 
 	if (hfunc)
 		*hfunc = ETH_RSS_HASH_TOP;
 	if (indir)
-		memcpy(indir, ctx->rx_indir_table, sizeof(ctx->rx_indir_table));
+		memcpy(indir, ctx.rx_indir_table, sizeof(ctx.rx_indir_table));
 	if (key)
-		memcpy(key, ctx->rx_hash_key, efx->type->rx_hash_key_size);
+		memcpy(key, ctx.rx_hash_key, efx->type->rx_hash_key_size);
 out_unlock:
-	mutex_unlock(&efx->rss_lock);
+	mutex_unlock(&net_dev->ethtool->rss_lock);
 	return rc;
 }
 
-int efx_ethtool_set_rxfh_context(struct net_device *net_dev,
-				 const u32 *indir, const u8 *key,
-				 const u8 hfunc, u32 *rss_context,
-				 bool delete)
+int efx_ethtool_modify_rxfh_context(struct net_device *net_dev,
+				    struct ethtool_rxfh_context *ctx,
+				    const u32 *indir, const u8 *key,
+				    const u8 hfunc, u32 rss_context,
+				    struct netlink_ext_ack *extack)
 {
 	struct efx_nic *efx = efx_netdev_priv(net_dev);
-	struct efx_rss_context *ctx;
-	bool allocated = false;
-	int rc;
+	struct efx_rss_context_priv *priv;
 
-	if (!efx->type->rx_push_rss_context_config)
+	if (!efx->type->rx_push_rss_context_config) {
+		NL_SET_ERR_MSG_MOD(extack,
+				   "NIC type does not support custom contexts");
 		return -EOPNOTSUPP;
+	}
 	/* Hash function is Toeplitz, cannot be changed */
-	if (hfunc != ETH_RSS_HASH_NO_CHANGE && hfunc != ETH_RSS_HASH_TOP)
+	if (hfunc != ETH_RSS_HASH_NO_CHANGE && hfunc != ETH_RSS_HASH_TOP) {
+		NL_SET_ERR_MSG_MOD(extack, "Only Toeplitz hash is supported");
 		return -EOPNOTSUPP;
+	}
 
-	mutex_lock(&efx->rss_lock);
+	priv = ethtool_rxfh_context_priv(ctx);
 
-	if (*rss_context == ETH_RXFH_CONTEXT_ALLOC) {
-		if (delete) {
-			/* alloc + delete == Nothing to do */
-			rc = -EINVAL;
-			goto out_unlock;
-		}
-		ctx = efx_alloc_rss_context_entry(efx);
-		if (!ctx) {
-			rc = -ENOMEM;
-			goto out_unlock;
-		}
-		ctx->context_id = EFX_MCDI_RSS_CONTEXT_INVALID;
-		/* Initialise indir table and key to defaults */
-		efx_set_default_rx_indir_table(efx, ctx);
-		netdev_rss_key_fill(ctx->rx_hash_key, sizeof(ctx->rx_hash_key));
-		allocated = true;
-	} else {
-		ctx = efx_find_rss_context_entry(efx, *rss_context);
-		if (!ctx) {
-			rc = -ENOENT;
-			goto out_unlock;
-		}
-	}
+	if (!key)
+		key = ethtool_rxfh_context_key(ctx);
+	if (!indir)
+		indir = ethtool_rxfh_context_indir(ctx);
 
-	if (delete) {
-		/* delete this context */
-		rc = efx->type->rx_push_rss_context_config(efx, ctx, NULL, NULL);
-		if (!rc)
-			efx_free_rss_context_entry(ctx);
-		goto out_unlock;
+	return efx->type->rx_push_rss_context_config(efx, priv, indir, key,
+						     false);
+}
+
+int efx_ethtool_create_rxfh_context(struct net_device *net_dev,
+				    struct ethtool_rxfh_context *ctx,
+				    const u32 *indir, const u8 *key,
+				    const u8 hfunc, u32 rss_context,
+				    struct netlink_ext_ack *extack)
+{
+	struct efx_nic *efx = efx_netdev_priv(net_dev);
+	struct efx_rss_context_priv *priv;
+
+	if (!efx->type->rx_push_rss_context_config) {
+		NL_SET_ERR_MSG_MOD(extack,
+				   "NIC type does not support custom contexts");
+		return -EOPNOTSUPP;
+	}
+	/* Hash function is Toeplitz, cannot be changed */
+	if (hfunc != ETH_RSS_HASH_NO_CHANGE && hfunc != ETH_RSS_HASH_TOP) {
+		NL_SET_ERR_MSG_MOD(extack, "Only Toeplitz hash is supported");
+		return -EOPNOTSUPP;
 	}
 
-	if (!key)
-		key = ctx->rx_hash_key;
+	priv = ethtool_rxfh_context_priv(ctx);
+
+	priv->context_id = EFX_MCDI_RSS_CONTEXT_INVALID;
+	priv->rx_hash_udp_4tuple = false;
+	/* Generate default indir table and/or key if not specified.
+	 * We use ctx as a place to store these; this is fine because
+	 * we're doing a create, so if we fail then the ctx will just
+	 * be deleted.
+	 */
 	if (!indir)
-		indir = ctx->rx_indir_table;
+		efx_set_default_rx_indir_table(efx, ethtool_rxfh_context_indir(ctx));
+	if (!key)
+		netdev_rss_key_fill(ethtool_rxfh_context_key(ctx),
+				    ctx->key_size);
+	return efx_ethtool_modify_rxfh_context(net_dev, ctx, indir, key, hfunc,
+					       rss_context, extack);
+}
 
-	rc = efx->type->rx_push_rss_context_config(efx, ctx, indir, key);
-	if (rc && allocated)
-		efx_free_rss_context_entry(ctx);
-	else
-		*rss_context = ctx->user_id;
-out_unlock:
-	mutex_unlock(&efx->rss_lock);
-	return rc;
+int efx_ethtool_remove_rxfh_context(struct net_device *net_dev,
+				    struct ethtool_rxfh_context *ctx,
+				    u32 rss_context,
+				    struct netlink_ext_ack *extack)
+{
+	struct efx_nic *efx = efx_netdev_priv(net_dev);
+	struct efx_rss_context_priv *priv;
+
+	if (!efx->type->rx_push_rss_context_config) {
+		NL_SET_ERR_MSG_MOD(extack,
+				   "NIC type does not support custom contexts");
+		return -EOPNOTSUPP;
+	}
+
+	priv = ethtool_rxfh_context_priv(ctx);
+	return efx->type->rx_push_rss_context_config(efx, priv, NULL, NULL,
+						     true);
 }
 
 int efx_ethtool_reset(struct net_device *net_dev, u32 *flags)
diff --git a/drivers/net/ethernet/sfc/ethtool_common.h b/drivers/net/ethernet/sfc/ethtool_common.h
index 659491932101..3df852eaab20 100644
--- a/drivers/net/ethernet/sfc/ethtool_common.h
+++ b/drivers/net/ethernet/sfc/ethtool_common.h
@@ -50,10 +50,20 @@ int efx_ethtool_set_rxfh(struct net_device *net_dev,
 			 const u32 *indir, const u8 *key, const u8 hfunc);
 int efx_ethtool_get_rxfh_context(struct net_device *net_dev, u32 *indir,
 				 u8 *key, u8 *hfunc, u32 rss_context);
-int efx_ethtool_set_rxfh_context(struct net_device *net_dev,
-				 const u32 *indir, const u8 *key,
-				 const u8 hfunc, u32 *rss_context,
-				 bool delete);
+int efx_ethtool_create_rxfh_context(struct net_device *net_dev,
+				    struct ethtool_rxfh_context *ctx,
+				    const u32 *indir, const u8 *key,
+				    const u8 hfunc, u32 rss_context,
+				    struct netlink_ext_ack *extack);
+int efx_ethtool_modify_rxfh_context(struct net_device *net_dev,
+				    struct ethtool_rxfh_context *ctx,
+				    const u32 *indir, const u8 *key,
+				    const u8 hfunc, u32 rss_context,
+				    struct netlink_ext_ack *extack);
+int efx_ethtool_remove_rxfh_context(struct net_device *net_dev,
+				    struct ethtool_rxfh_context *ctx,
+				    u32 rss_context,
+				    struct netlink_ext_ack *extack);
 int efx_ethtool_reset(struct net_device *net_dev, u32 *flags);
 int efx_ethtool_get_module_eeprom(struct net_device *net_dev,
 				  struct ethtool_eeprom *ee,
diff --git a/drivers/net/ethernet/sfc/mcdi_filters.c b/drivers/net/ethernet/sfc/mcdi_filters.c
index 4ff6586116ee..fa6eb4ec170a 100644
--- a/drivers/net/ethernet/sfc/mcdi_filters.c
+++ b/drivers/net/ethernet/sfc/mcdi_filters.c
@@ -194,7 +194,7 @@ efx_mcdi_filter_push_prep_set_match_fields(struct efx_nic *efx,
 static void efx_mcdi_filter_push_prep(struct efx_nic *efx,
 				      const struct efx_filter_spec *spec,
 				      efx_dword_t *inbuf, u64 handle,
-				      struct efx_rss_context *ctx,
+				      struct efx_rss_context_priv *ctx,
 				      bool replacing)
 {
 	u32 flags = spec->flags;
@@ -245,7 +245,7 @@ static void efx_mcdi_filter_push_prep(struct efx_nic *efx,
 
 static int efx_mcdi_filter_push(struct efx_nic *efx,
 				const struct efx_filter_spec *spec, u64 *handle,
-				struct efx_rss_context *ctx, bool replacing)
+				struct efx_rss_context_priv *ctx, bool replacing)
 {
 	MCDI_DECLARE_BUF(inbuf, MC_CMD_FILTER_OP_EXT_IN_LEN);
 	MCDI_DECLARE_BUF(outbuf, MC_CMD_FILTER_OP_EXT_OUT_LEN);
@@ -345,9 +345,9 @@ static s32 efx_mcdi_filter_insert_locked(struct efx_nic *efx,
 					 bool replace_equal)
 {
 	DECLARE_BITMAP(mc_rem_map, EFX_EF10_FILTER_SEARCH_LIMIT);
+	struct efx_rss_context_priv *ctx = NULL;
 	struct efx_mcdi_filter_table *table;
 	struct efx_filter_spec *saved_spec;
-	struct efx_rss_context *ctx = NULL;
 	unsigned int match_pri, hash;
 	unsigned int priv_flags;
 	bool rss_locked = false;
@@ -380,12 +380,12 @@ static s32 efx_mcdi_filter_insert_locked(struct efx_nic *efx,
 		bitmap_zero(mc_rem_map, EFX_EF10_FILTER_SEARCH_LIMIT);
 
 	if (spec->flags & EFX_FILTER_FLAG_RX_RSS) {
-		mutex_lock(&efx->rss_lock);
+		mutex_lock(&efx->net_dev->ethtool->rss_lock);
 		rss_locked = true;
 		if (spec->rss_context)
 			ctx = efx_find_rss_context_entry(efx, spec->rss_context);
 		else
-			ctx = &efx->rss_context;
+			ctx = &efx->rss_context.priv;
 		if (!ctx) {
 			rc = -ENOENT;
 			goto out_unlock;
@@ -548,7 +548,7 @@ static s32 efx_mcdi_filter_insert_locked(struct efx_nic *efx,
 
 out_unlock:
 	if (rss_locked)
-		mutex_unlock(&efx->rss_lock);
+		mutex_unlock(&efx->net_dev->ethtool->rss_lock);
 	up_write(&table->lock);
 	return rc;
 }
@@ -611,13 +611,13 @@ static int efx_mcdi_filter_remove_internal(struct efx_nic *efx,
 
 		new_spec.priority = EFX_FILTER_PRI_AUTO;
 		new_spec.flags = (EFX_FILTER_FLAG_RX |
-				  (efx_rss_active(&efx->rss_context) ?
+				  (efx_rss_active(&efx->rss_context.priv) ?
 				   EFX_FILTER_FLAG_RX_RSS : 0));
 		new_spec.dmaq_id = 0;
 		new_spec.rss_context = 0;
 		rc = efx_mcdi_filter_push(efx, &new_spec,
 					  &table->entry[filter_idx].handle,
-					  &efx->rss_context,
+					  &efx->rss_context.priv,
 					  true);
 
 		if (rc == 0)
@@ -764,7 +764,7 @@ static int efx_mcdi_filter_insert_addr_list(struct efx_nic *efx,
 		ids = vlan->uc;
 	}
 
-	filter_flags = efx_rss_active(&efx->rss_context) ? EFX_FILTER_FLAG_RX_RSS : 0;
+	filter_flags = efx_rss_active(&efx->rss_context.priv) ? EFX_FILTER_FLAG_RX_RSS : 0;
 
 	/* Insert/renew filters */
 	for (i = 0; i < addr_count; i++) {
@@ -833,7 +833,7 @@ static int efx_mcdi_filter_insert_def(struct efx_nic *efx,
 	int rc;
 	u16 *id;
 
-	filter_flags = efx_rss_active(&efx->rss_context) ? EFX_FILTER_FLAG_RX_RSS : 0;
+	filter_flags = efx_rss_active(&efx->rss_context.priv) ? EFX_FILTER_FLAG_RX_RSS : 0;
 
 	efx_filter_init_rx(&spec, EFX_FILTER_PRI_AUTO, filter_flags, 0);
 
@@ -1375,8 +1375,8 @@ void efx_mcdi_filter_table_restore(struct efx_nic *efx)
 	struct efx_mcdi_filter_table *table = efx->filter_state;
 	unsigned int invalid_filters = 0, failed = 0;
 	struct efx_mcdi_filter_vlan *vlan;
+	struct efx_rss_context_priv *ctx;
 	struct efx_filter_spec *spec;
-	struct efx_rss_context *ctx;
 	unsigned int filter_idx;
 	u32 mcdi_flags;
 	int match_pri;
@@ -1388,7 +1388,7 @@ void efx_mcdi_filter_table_restore(struct efx_nic *efx)
 		return;
 
 	down_write(&table->lock);
-	mutex_lock(&efx->rss_lock);
+	mutex_lock(&efx->net_dev->ethtool->rss_lock);
 
 	for (filter_idx = 0; filter_idx < EFX_MCDI_FILTER_TBL_ROWS; filter_idx++) {
 		spec = efx_mcdi_filter_entry_spec(table, filter_idx);
@@ -1407,7 +1407,7 @@ void efx_mcdi_filter_table_restore(struct efx_nic *efx)
 		if (spec->rss_context)
 			ctx = efx_find_rss_context_entry(efx, spec->rss_context);
 		else
-			ctx = &efx->rss_context;
+			ctx = &efx->rss_context.priv;
 		if (spec->flags & EFX_FILTER_FLAG_RX_RSS) {
 			if (!ctx) {
 				netif_warn(efx, drv, efx->net_dev,
@@ -1444,7 +1444,7 @@ void efx_mcdi_filter_table_restore(struct efx_nic *efx)
 		}
 	}
 
-	mutex_unlock(&efx->rss_lock);
+	mutex_unlock(&efx->net_dev->ethtool->rss_lock);
 	up_write(&table->lock);
 
 	/*
@@ -1861,7 +1861,8 @@ bool efx_mcdi_filter_rfs_expire_one(struct efx_nic *efx, u32 flow_id,
 					 RSS_MODE_HASH_ADDRS << MC_CMD_RSS_CONTEXT_GET_FLAGS_OUT_UDP_IPV6_RSS_MODE_LBN |\
 					 RSS_MODE_HASH_ADDRS << MC_CMD_RSS_CONTEXT_GET_FLAGS_OUT_OTHER_IPV6_RSS_MODE_LBN)
 
-int efx_mcdi_get_rss_context_flags(struct efx_nic *efx, u32 context, u32 *flags)
+static int efx_mcdi_get_rss_context_flags(struct efx_nic *efx, u32 context,
+					  u32 *flags)
 {
 	/*
 	 * Firmware had a bug (sfc bug 61952) where it would not actually
@@ -1909,8 +1910,8 @@ int efx_mcdi_get_rss_context_flags(struct efx_nic *efx, u32 context, u32 *flags)
  * Defaults are 4-tuple for TCP and 2-tuple for UDP and other-IP, so we
  * just need to set the UDP ports flags (for both IP versions).
  */
-void efx_mcdi_set_rss_context_flags(struct efx_nic *efx,
-				    struct efx_rss_context *ctx)
+static void efx_mcdi_set_rss_context_flags(struct efx_nic *efx,
+					   struct efx_rss_context_priv *ctx)
 {
 	MCDI_DECLARE_BUF(inbuf, MC_CMD_RSS_CONTEXT_SET_FLAGS_IN_LEN);
 	u32 flags;
@@ -1931,7 +1932,7 @@ void efx_mcdi_set_rss_context_flags(struct efx_nic *efx,
 }
 
 static int efx_mcdi_filter_alloc_rss_context(struct efx_nic *efx, bool exclusive,
-					     struct efx_rss_context *ctx,
+					     struct efx_rss_context_priv *ctx,
 					     unsigned *context_size)
 {
 	MCDI_DECLARE_BUF(inbuf, MC_CMD_RSS_CONTEXT_ALLOC_IN_LEN);
@@ -2032,25 +2033,26 @@ void efx_mcdi_rx_free_indir_table(struct efx_nic *efx)
 {
 	int rc;
 
-	if (efx->rss_context.context_id != EFX_MCDI_RSS_CONTEXT_INVALID) {
-		rc = efx_mcdi_filter_free_rss_context(efx, efx->rss_context.context_id);
+	if (efx->rss_context.priv.context_id != EFX_MCDI_RSS_CONTEXT_INVALID) {
+		rc = efx_mcdi_filter_free_rss_context(efx, efx->rss_context.priv.context_id);
 		WARN_ON(rc != 0);
 	}
-	efx->rss_context.context_id = EFX_MCDI_RSS_CONTEXT_INVALID;
+	efx->rss_context.priv.context_id = EFX_MCDI_RSS_CONTEXT_INVALID;
 }
 
 static int efx_mcdi_filter_rx_push_shared_rss_config(struct efx_nic *efx,
 					      unsigned *context_size)
 {
 	struct efx_mcdi_filter_table *table = efx->filter_state;
-	int rc = efx_mcdi_filter_alloc_rss_context(efx, false, &efx->rss_context,
-					    context_size);
+	int rc = efx_mcdi_filter_alloc_rss_context(efx, false,
+						   &efx->rss_context.priv,
+						   context_size);
 
 	if (rc != 0)
 		return rc;
 
 	table->rx_rss_context_exclusive = false;
-	efx_set_default_rx_indir_table(efx, &efx->rss_context);
+	efx_set_default_rx_indir_table(efx, efx->rss_context.rx_indir_table);
 	return 0;
 }
 
@@ -2058,26 +2060,27 @@ static int efx_mcdi_filter_rx_push_exclusive_rss_config(struct efx_nic *efx,
 						 const u32 *rx_indir_table,
 						 const u8 *key)
 {
+	u32 old_rx_rss_context = efx->rss_context.priv.context_id;
 	struct efx_mcdi_filter_table *table = efx->filter_state;
-	u32 old_rx_rss_context = efx->rss_context.context_id;
 	int rc;
 
-	if (efx->rss_context.context_id == EFX_MCDI_RSS_CONTEXT_INVALID ||
+	if (efx->rss_context.priv.context_id == EFX_MCDI_RSS_CONTEXT_INVALID ||
 	    !table->rx_rss_context_exclusive) {
-		rc = efx_mcdi_filter_alloc_rss_context(efx, true, &efx->rss_context,
-						NULL);
+		rc = efx_mcdi_filter_alloc_rss_context(efx, true,
+						       &efx->rss_context.priv,
+						       NULL);
 		if (rc == -EOPNOTSUPP)
 			return rc;
 		else if (rc != 0)
 			goto fail1;
 	}
 
-	rc = efx_mcdi_filter_populate_rss_table(efx, efx->rss_context.context_id,
-					 rx_indir_table, key);
+	rc = efx_mcdi_filter_populate_rss_table(efx, efx->rss_context.priv.context_id,
+						rx_indir_table, key);
 	if (rc != 0)
 		goto fail2;
 
-	if (efx->rss_context.context_id != old_rx_rss_context &&
+	if (efx->rss_context.priv.context_id != old_rx_rss_context &&
 	    old_rx_rss_context != EFX_MCDI_RSS_CONTEXT_INVALID)
 		WARN_ON(efx_mcdi_filter_free_rss_context(efx, old_rx_rss_context) != 0);
 	table->rx_rss_context_exclusive = true;
@@ -2091,9 +2094,9 @@ static int efx_mcdi_filter_rx_push_exclusive_rss_config(struct efx_nic *efx,
 	return 0;
 
 fail2:
-	if (old_rx_rss_context != efx->rss_context.context_id) {
-		WARN_ON(efx_mcdi_filter_free_rss_context(efx, efx->rss_context.context_id) != 0);
-		efx->rss_context.context_id = old_rx_rss_context;
+	if (old_rx_rss_context != efx->rss_context.priv.context_id) {
+		WARN_ON(efx_mcdi_filter_free_rss_context(efx, efx->rss_context.priv.context_id) != 0);
+		efx->rss_context.priv.context_id = old_rx_rss_context;
 	}
 fail1:
 	netif_err(efx, hw, efx->net_dev, "%s: failed rc=%d\n", __func__, rc);
@@ -2101,33 +2104,28 @@ static int efx_mcdi_filter_rx_push_exclusive_rss_config(struct efx_nic *efx,
 }
 
 int efx_mcdi_rx_push_rss_context_config(struct efx_nic *efx,
-					struct efx_rss_context *ctx,
+					struct efx_rss_context_priv *ctx,
 					const u32 *rx_indir_table,
-					const u8 *key)
+					const u8 *key, bool delete)
 {
 	int rc;
 
-	WARN_ON(!mutex_is_locked(&efx->rss_lock));
+	WARN_ON(!mutex_is_locked(&efx->net_dev->ethtool->rss_lock));
 
 	if (ctx->context_id == EFX_MCDI_RSS_CONTEXT_INVALID) {
+		if (delete)
+			/* already wasn't in HW, nothing to do */
+			return 0;
 		rc = efx_mcdi_filter_alloc_rss_context(efx, true, ctx, NULL);
 		if (rc)
 			return rc;
 	}
 
-	if (!rx_indir_table) /* Delete this context */
+	if (delete) /* Delete this context */
 		return efx_mcdi_filter_free_rss_context(efx, ctx->context_id);
 
-	rc = efx_mcdi_filter_populate_rss_table(efx, ctx->context_id,
-					 rx_indir_table, key);
-	if (rc)
-		return rc;
-
-	memcpy(ctx->rx_indir_table, rx_indir_table,
-	       sizeof(efx->rss_context.rx_indir_table));
-	memcpy(ctx->rx_hash_key, key, efx->type->rx_hash_key_size);
-
-	return 0;
+	return efx_mcdi_filter_populate_rss_table(efx, ctx->context_id,
+						  rx_indir_table, key);
 }
 
 int efx_mcdi_rx_pull_rss_context_config(struct efx_nic *efx,
@@ -2139,16 +2137,16 @@ int efx_mcdi_rx_pull_rss_context_config(struct efx_nic *efx,
 	size_t outlen;
 	int rc, i;
 
-	WARN_ON(!mutex_is_locked(&efx->rss_lock));
+	WARN_ON(!mutex_is_locked(&efx->net_dev->ethtool->rss_lock));
 
 	BUILD_BUG_ON(MC_CMD_RSS_CONTEXT_GET_TABLE_IN_LEN !=
 		     MC_CMD_RSS_CONTEXT_GET_KEY_IN_LEN);
 
-	if (ctx->context_id == EFX_MCDI_RSS_CONTEXT_INVALID)
+	if (ctx->priv.context_id == EFX_MCDI_RSS_CONTEXT_INVALID)
 		return -ENOENT;
 
 	MCDI_SET_DWORD(inbuf, RSS_CONTEXT_GET_TABLE_IN_RSS_CONTEXT_ID,
-		       ctx->context_id);
+		       ctx->priv.context_id);
 	BUILD_BUG_ON(ARRAY_SIZE(ctx->rx_indir_table) !=
 		     MC_CMD_RSS_CONTEXT_GET_TABLE_OUT_INDIRECTION_TABLE_LEN);
 	rc = efx_mcdi_rpc(efx, MC_CMD_RSS_CONTEXT_GET_TABLE, inbuf, sizeof(inbuf),
@@ -2164,7 +2162,7 @@ int efx_mcdi_rx_pull_rss_context_config(struct efx_nic *efx,
 				RSS_CONTEXT_GET_TABLE_OUT_INDIRECTION_TABLE)[i];
 
 	MCDI_SET_DWORD(inbuf, RSS_CONTEXT_GET_KEY_IN_RSS_CONTEXT_ID,
-		       ctx->context_id);
+		       ctx->priv.context_id);
 	BUILD_BUG_ON(ARRAY_SIZE(ctx->rx_hash_key) !=
 		     MC_CMD_RSS_CONTEXT_SET_KEY_IN_TOEPLITZ_KEY_LEN);
 	rc = efx_mcdi_rpc(efx, MC_CMD_RSS_CONTEXT_GET_KEY, inbuf, sizeof(inbuf),
@@ -2186,35 +2184,42 @@ int efx_mcdi_rx_pull_rss_config(struct efx_nic *efx)
 {
 	int rc;
 
-	mutex_lock(&efx->rss_lock);
+	mutex_lock(&efx->net_dev->ethtool->rss_lock);
 	rc = efx_mcdi_rx_pull_rss_context_config(efx, &efx->rss_context);
-	mutex_unlock(&efx->rss_lock);
+	mutex_unlock(&efx->net_dev->ethtool->rss_lock);
 	return rc;
 }
 
 void efx_mcdi_rx_restore_rss_contexts(struct efx_nic *efx)
 {
 	struct efx_mcdi_filter_table *table = efx->filter_state;
-	struct efx_rss_context *ctx;
+	struct ethtool_rxfh_context *ctx;
+	u32 context;
 	int rc;
 
-	WARN_ON(!mutex_is_locked(&efx->rss_lock));
+	WARN_ON(!mutex_is_locked(&efx->net_dev->ethtool->rss_lock));
 
 	if (!table->must_restore_rss_contexts)
 		return;
 
-	list_for_each_entry(ctx, &efx->rss_context.list, list) {
+	idr_for_each_entry(&efx->net_dev->ethtool->rss_ctx, ctx, context) {
+		struct efx_rss_context_priv *priv;
+		u32 *indir;
+		u8 *key;
+
+		priv = ethtool_rxfh_context_priv(ctx);
 		/* previous NIC RSS context is gone */
-		ctx->context_id = EFX_MCDI_RSS_CONTEXT_INVALID;
+		priv->context_id = EFX_MCDI_RSS_CONTEXT_INVALID;
 		/* so try to allocate a new one */
-		rc = efx_mcdi_rx_push_rss_context_config(efx, ctx,
-							 ctx->rx_indir_table,
-							 ctx->rx_hash_key);
+		indir = ethtool_rxfh_context_indir(ctx);
+		key = ethtool_rxfh_context_key(ctx);
+		rc = efx_mcdi_rx_push_rss_context_config(efx, priv, indir, key,
+							 false);
 		if (rc)
 			netif_warn(efx, probe, efx->net_dev,
 				   "failed to restore RSS context %u, rc=%d"
 				   "; RSS filters may fail to be applied\n",
-				   ctx->user_id, rc);
+				   context, rc);
 	}
 	table->must_restore_rss_contexts = false;
 }
@@ -2276,7 +2281,7 @@ int efx_mcdi_vf_rx_push_rss_config(struct efx_nic *efx, bool user,
 {
 	if (user)
 		return -EOPNOTSUPP;
-	if (efx->rss_context.context_id != EFX_MCDI_RSS_CONTEXT_INVALID)
+	if (efx->rss_context.priv.context_id != EFX_MCDI_RSS_CONTEXT_INVALID)
 		return 0;
 	return efx_mcdi_filter_rx_push_shared_rss_config(efx, NULL);
 }
@@ -2295,7 +2300,7 @@ int efx_mcdi_push_default_indir_table(struct efx_nic *efx,
 
 	efx_mcdi_rx_free_indir_table(efx);
 	if (rss_spread > 1) {
-		efx_set_default_rx_indir_table(efx, &efx->rss_context);
+		efx_set_default_rx_indir_table(efx, efx->rss_context.rx_indir_table);
 		rc = efx->type->rx_push_rss_config(efx, false,
 				   efx->rss_context.rx_indir_table, NULL);
 	}
diff --git a/drivers/net/ethernet/sfc/mcdi_filters.h b/drivers/net/ethernet/sfc/mcdi_filters.h
index c0d6558b9fd2..11b9f87ed9e1 100644
--- a/drivers/net/ethernet/sfc/mcdi_filters.h
+++ b/drivers/net/ethernet/sfc/mcdi_filters.h
@@ -145,9 +145,9 @@ void efx_mcdi_filter_del_vlan(struct efx_nic *efx, u16 vid);
 
 void efx_mcdi_rx_free_indir_table(struct efx_nic *efx);
 int efx_mcdi_rx_push_rss_context_config(struct efx_nic *efx,
-					struct efx_rss_context *ctx,
+					struct efx_rss_context_priv *ctx,
 					const u32 *rx_indir_table,
-					const u8 *key);
+					const u8 *key, bool delete);
 int efx_mcdi_pf_rx_push_rss_config(struct efx_nic *efx, bool user,
 				   const u32 *rx_indir_table,
 				   const u8 *key);
@@ -161,10 +161,6 @@ int efx_mcdi_push_default_indir_table(struct efx_nic *efx,
 int efx_mcdi_rx_pull_rss_config(struct efx_nic *efx);
 int efx_mcdi_rx_pull_rss_context_config(struct efx_nic *efx,
 					struct efx_rss_context *ctx);
-int efx_mcdi_get_rss_context_flags(struct efx_nic *efx, u32 context,
-				   u32 *flags);
-void efx_mcdi_set_rss_context_flags(struct efx_nic *efx,
-				    struct efx_rss_context *ctx);
 void efx_mcdi_rx_restore_rss_contexts(struct efx_nic *efx);
 
 static inline void efx_mcdi_update_rx_scatter(struct efx_nic *efx)
diff --git a/drivers/net/ethernet/sfc/net_driver.h b/drivers/net/ethernet/sfc/net_driver.h
index 27d86e90a3bb..d2a54a03f84d 100644
--- a/drivers/net/ethernet/sfc/net_driver.h
+++ b/drivers/net/ethernet/sfc/net_driver.h
@@ -737,21 +737,24 @@ struct vfdi_status;
 /* The reserved RSS context value */
 #define EFX_MCDI_RSS_CONTEXT_INVALID	0xffffffff
 /**
- * struct efx_rss_context - A user-defined RSS context for filtering
- * @list: node of linked list on which this struct is stored
+ * struct efx_rss_context_priv - driver private data for an RSS context
  * @context_id: the RSS_CONTEXT_ID returned by MC firmware, or
  *	%EFX_MCDI_RSS_CONTEXT_INVALID if this context is not present on the NIC.
- *	For Siena, 0 if RSS is active, else %EFX_MCDI_RSS_CONTEXT_INVALID.
- * @user_id: the rss_context ID exposed to userspace over ethtool.
  * @rx_hash_udp_4tuple: UDP 4-tuple hashing enabled
+ */
+struct efx_rss_context_priv {
+	u32 context_id;
+	bool rx_hash_udp_4tuple;
+};
+
+/**
+ * struct efx_rss_context - an RSS context
+ * @priv: hardware-specific state
  * @rx_hash_key: Toeplitz hash key for this RSS context
  * @indir_table: Indirection table for this RSS context
  */
 struct efx_rss_context {
-	struct list_head list;
-	u32 context_id;
-	u32 user_id;
-	bool rx_hash_udp_4tuple;
+	struct efx_rss_context_priv priv;
 	u8 rx_hash_key[40];
 	u32 rx_indir_table[128];
 };
@@ -883,9 +886,7 @@ struct efx_mae;
  * @rx_packet_ts_offset: Offset of timestamp from start of packet data
  *	(valid only if channel->sync_timestamps_enabled; always negative)
  * @rx_scatter: Scatter mode enabled for receives
- * @rss_context: Main RSS context.  Its @list member is the head of the list of
- *	RSS contexts created by user requests
- * @rss_lock: Protects custom RSS context software state in @rss_context.list
+ * @rss_context: Main RSS context.
  * @vport_id: The function's vport ID, only relevant for PFs
  * @int_error_count: Number of internal errors seen recently
  * @int_error_expire: Time at which error count will be expired
@@ -1052,7 +1053,6 @@ struct efx_nic {
 	int rx_packet_ts_offset;
 	bool rx_scatter;
 	struct efx_rss_context rss_context;
-	struct mutex rss_lock;
 	u32 vport_id;
 
 	unsigned int_error_count;
@@ -1416,9 +1416,9 @@ struct efx_nic_type {
 				  const u32 *rx_indir_table, const u8 *key);
 	int (*rx_pull_rss_config)(struct efx_nic *efx);
 	int (*rx_push_rss_context_config)(struct efx_nic *efx,
-					  struct efx_rss_context *ctx,
+					  struct efx_rss_context_priv *ctx,
 					  const u32 *rx_indir_table,
-					  const u8 *key);
+					  const u8 *key, bool delete);
 	int (*rx_pull_rss_context_config)(struct efx_nic *efx,
 					  struct efx_rss_context *ctx);
 	void (*rx_restore_rss_contexts)(struct efx_nic *efx);
diff --git a/drivers/net/ethernet/sfc/rx_common.c b/drivers/net/ethernet/sfc/rx_common.c
index d2f35ee15eff..f5632c210ab2 100644
--- a/drivers/net/ethernet/sfc/rx_common.c
+++ b/drivers/net/ethernet/sfc/rx_common.c
@@ -556,69 +556,25 @@ efx_rx_packet_gro(struct efx_channel *channel, struct efx_rx_buffer *rx_buf,
 	napi_gro_frags(napi);
 }
 
-/* RSS contexts.  We're using linked lists and crappy O(n) algorithms, because
- * (a) this is an infrequent control-plane operation and (b) n is small (max 64)
- */
-struct efx_rss_context *efx_alloc_rss_context_entry(struct efx_nic *efx)
+struct efx_rss_context_priv *efx_find_rss_context_entry(struct efx_nic *efx,
+							u32 id)
 {
-	struct list_head *head = &efx->rss_context.list;
-	struct efx_rss_context *ctx, *new;
-	u32 id = 1; /* Don't use zero, that refers to the master RSS context */
-
-	WARN_ON(!mutex_is_locked(&efx->rss_lock));
+	struct ethtool_rxfh_context *ctx;
 
-	/* Search for first gap in the numbering */
-	list_for_each_entry(ctx, head, list) {
-		if (ctx->user_id != id)
-			break;
-		id++;
-		/* Check for wrap.  If this happens, we have nearly 2^32
-		 * allocated RSS contexts, which seems unlikely.
-		 */
-		if (WARN_ON_ONCE(!id))
-			return NULL;
-	}
+	WARN_ON(!mutex_is_locked(&efx->net_dev->ethtool->rss_lock));
 
-	/* Create the new entry */
-	new = kmalloc(sizeof(*new), GFP_KERNEL);
-	if (!new)
+	ctx = idr_find(&efx->net_dev->ethtool->rss_ctx, id);
+	if (!ctx)
 		return NULL;
-	new->context_id = EFX_MCDI_RSS_CONTEXT_INVALID;
-	new->rx_hash_udp_4tuple = false;
-
-	/* Insert the new entry into the gap */
-	new->user_id = id;
-	list_add_tail(&new->list, &ctx->list);
-	return new;
-}
-
-struct efx_rss_context *efx_find_rss_context_entry(struct efx_nic *efx, u32 id)
-{
-	struct list_head *head = &efx->rss_context.list;
-	struct efx_rss_context *ctx;
-
-	WARN_ON(!mutex_is_locked(&efx->rss_lock));
-
-	list_for_each_entry(ctx, head, list)
-		if (ctx->user_id == id)
-			return ctx;
-	return NULL;
-}
-
-void efx_free_rss_context_entry(struct efx_rss_context *ctx)
-{
-	list_del(&ctx->list);
-	kfree(ctx);
+	return ethtool_rxfh_context_priv(ctx);
 }
 
-void efx_set_default_rx_indir_table(struct efx_nic *efx,
-				    struct efx_rss_context *ctx)
+void efx_set_default_rx_indir_table(struct efx_nic *efx, u32 *indir)
 {
 	size_t i;
 
-	for (i = 0; i < ARRAY_SIZE(ctx->rx_indir_table); i++)
-		ctx->rx_indir_table[i] =
-			ethtool_rxfh_indir_default(i, efx->rss_spread);
+	for (i = 0; i < ARRAY_SIZE(efx->rss_context.rx_indir_table); i++)
+		indir[i] = ethtool_rxfh_indir_default(i, efx->rss_spread);
 }
 
 /**
diff --git a/drivers/net/ethernet/sfc/rx_common.h b/drivers/net/ethernet/sfc/rx_common.h
index fbd2769307f9..75fa84192362 100644
--- a/drivers/net/ethernet/sfc/rx_common.h
+++ b/drivers/net/ethernet/sfc/rx_common.h
@@ -84,11 +84,9 @@ void
 efx_rx_packet_gro(struct efx_channel *channel, struct efx_rx_buffer *rx_buf,
 		  unsigned int n_frags, u8 *eh, __wsum csum);
 
-struct efx_rss_context *efx_alloc_rss_context_entry(struct efx_nic *efx);
-struct efx_rss_context *efx_find_rss_context_entry(struct efx_nic *efx, u32 id);
-void efx_free_rss_context_entry(struct efx_rss_context *ctx);
-void efx_set_default_rx_indir_table(struct efx_nic *efx,
-				    struct efx_rss_context *ctx);
+struct efx_rss_context_priv *efx_find_rss_context_entry(struct efx_nic *efx,
+							u32 id);
+void efx_set_default_rx_indir_table(struct efx_nic *efx, u32 *indir);
 
 bool efx_filter_is_mc_recipient(const struct efx_filter_spec *spec);
 bool efx_filter_spec_equal(const struct efx_filter_spec *left,

Re: [RFC PATCH v3 net-next 2/7] net: ethtool: attach an IDR of custom RSS contexts to a netdevice

[Russell King (Oracle)]

On Tue, Sep 12, 2023 at 03:21:37PM +0100, edward.cree@amd.com wrote:
> From: Edward Cree <ecree.xilinx@gmail.com>
> 
> Each context stores the RXFH settings (indir, key, and hfunc) as well
>  as optionally some driver private data.
> Delete any still-existing contexts at netdev unregister time.
> 
> Signed-off-by: Edward Cree <ecree.xilinx@gmail.com>
> ---
>  include/linux/ethtool.h | 43 ++++++++++++++++++++++++++++++++++++++++-
>  net/core/dev.c          | 23 ++++++++++++++++++++++
>  2 files changed, 65 insertions(+), 1 deletion(-)
> 
> diff --git a/include/linux/ethtool.h b/include/linux/ethtool.h
> index 8aeefc0b4e10..c770e32d79e6 100644
> --- a/include/linux/ethtool.h
> +++ b/include/linux/ethtool.h
> @@ -157,6 +157,43 @@ static inline u32 ethtool_rxfh_indir_default(u32 index, u32 n_rx_rings)
>  	return index % n_rx_rings;
>  }
>  
> +/**
> + * struct ethtool_rxfh_context - a custom RSS context configuration
> + * @indir_size: Number of u32 entries in indirection table
> + * @key_size: Size of hash key, in bytes
> + * @hfunc: RSS hash function identifier.  One of the %ETH_RSS_HASH_*
> + * @priv_size: Size of driver private data, in bytes
> + * @indir_no_change: indir was not specified at create time
> + * @key_no_change: hkey was not specified at create time
> + */
> +struct ethtool_rxfh_context {
> +	u32 indir_size;
> +	u32 key_size;
> +	u8 hfunc;
> +	u16 priv_size;
> +	u8 indir_no_change:1;
> +	u8 key_no_change:1;
> +	/* private: driver private data, indirection table, and hash key are
> +	 * stored sequentially in @data area.  Use below helpers to access.
> +	 */
> +	u8 data[] __aligned(sizeof(void *));
> +};
> +
> +static inline void *ethtool_rxfh_context_priv(struct ethtool_rxfh_context *ctx)
> +{
> +	return ctx->data;
> +}
> +
> +static inline u32 *ethtool_rxfh_context_indir(struct ethtool_rxfh_context *ctx)
> +{
> +	return (u32 *)(ctx->data + ALIGN(ctx->priv_size, sizeof(u32)));
> +}
> +
> +static inline u8 *ethtool_rxfh_context_key(struct ethtool_rxfh_context *ctx)
> +{
> +	return (u8 *)(ethtool_rxfh_context_indir(ctx) + ctx->indir_size);
> +}
> +
>  /* declare a link mode bitmap */
>  #define __ETHTOOL_DECLARE_LINK_MODE_MASK(name)		\
>  	DECLARE_BITMAP(name, __ETHTOOL_LINK_MODE_MASK_NBITS)
> @@ -937,10 +974,14 @@ int ethtool_virtdev_set_link_ksettings(struct net_device *dev,
>  
>  /**
>   * struct ethtool_netdev_state - per-netdevice state for ethtool features
> + * @rss_ctx:		IDR storing custom RSS context state
> + * @rss_ctx_max_id:	maximum (exclusive) supported RSS context ID
>   * @wol_enabled:	Wake-on-LAN is enabled
>   */
>  struct ethtool_netdev_state {
> -	unsigned		wol_enabled:1;
> +	struct idr		rss_ctx;

https://docs.kernel.org/core-api/idr.html

"The IDR interface is deprecated; please use the XArray instead."

-- 
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last!

Re: [RFC PATCH v3 net-next 6/7] net: ethtool: add a mutex protecting RSS contexts

[Russell King (Oracle)]

On Tue, Sep 12, 2023 at 03:21:41PM +0100, edward.cree@amd.com wrote:
> From: Edward Cree <ecree.xilinx@gmail.com>
> 
> While this is not needed to serialise the ethtool entry points (which
>  are all under RTNL), drivers may have cause to asynchronously access
>  dev->ethtool->rss_ctx; taking dev->ethtool->rss_lock allows them to
>  do this safely without needing to take the RTNL.
> 
> Signed-off-by: Edward Cree <ecree.xilinx@gmail.com>
> ---
>  include/linux/ethtool.h | 3 +++
>  net/core/dev.c          | 5 +++++
>  net/ethtool/ioctl.c     | 7 +++++++
>  3 files changed, 15 insertions(+)
> 
> diff --git a/include/linux/ethtool.h b/include/linux/ethtool.h
> index 8977aa8523e3..1f8293deebd5 100644
> --- a/include/linux/ethtool.h
> +++ b/include/linux/ethtool.h
> @@ -1026,11 +1026,14 @@ int ethtool_virtdev_set_link_ksettings(struct net_device *dev,
>  /**
>   * struct ethtool_netdev_state - per-netdevice state for ethtool features
>   * @rss_ctx:		IDR storing custom RSS context state
> + * @rss_lock:		Protects entries in @rss_ctx.  May be taken from
> + *			within RTNL.
>   * @rss_ctx_max_id:	maximum (exclusive) supported RSS context ID
>   * @wol_enabled:	Wake-on-LAN is enabled
>   */
>  struct ethtool_netdev_state {
>  	struct idr		rss_ctx;
> +	struct mutex		rss_lock;
>  	u32			rss_ctx_max_id;
>  	u32			wol_enabled:1;
>  };
> diff --git a/net/core/dev.c b/net/core/dev.c
> index f12767466427..2acb4d8cd4c7 100644
> --- a/net/core/dev.c
> +++ b/net/core/dev.c
> @@ -10054,6 +10054,7 @@ int register_netdevice(struct net_device *dev)
>  	idr_init_base(&dev->ethtool->rss_ctx, 1);
>  
>  	spin_lock_init(&dev->addr_list_lock);
> +	mutex_init(&dev->ethtool->rss_lock);

Is there a reason to split this from the idr (eventually xarray)
initialisation above? Surely initialisations for a feature (rss)
should all be grouped together?

-- 
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last!

Re: [RFC PATCH v3 net-next 2/7] net: ethtool: attach an IDR of custom RSS contexts to a netdevice

[Edward Cree]

On 12/09/2023 17:36, Russell King (Oracle) wrote:
> On Tue, Sep 12, 2023 at 03:21:37PM +0100, edward.cree@amd.com wrote:
>> +	struct idr		rss_ctx;
> 
> https://docs.kernel.org/core-api/idr.html
> 
> "The IDR interface is deprecated; please use the XArray instead."

IDR is a wrapper around XArray these days, right?
When I looked into the equivalent to use XArray directly it looked much
 more complicated for flexibility that really isn't needed here.
Is there an explanation you can point me at of why this extremely
 convenient wrapper is deprecated?

-e

Re: [RFC PATCH v3 net-next 6/7] net: ethtool: add a mutex protecting RSS contexts

[Edward Cree]

On 12/09/2023 17:40, Russell King (Oracle) wrote:
> On Tue, Sep 12, 2023 at 03:21:41PM +0100, edward.cree@amd.com wrote:
>> diff --git a/net/core/dev.c b/net/core/dev.c
>> index f12767466427..2acb4d8cd4c7 100644
>> --- a/net/core/dev.c
>> +++ b/net/core/dev.c
>> @@ -10054,6 +10054,7 @@ int register_netdevice(struct net_device *dev)
>>  	idr_init_base(&dev->ethtool->rss_ctx, 1);
>>  
>>  	spin_lock_init(&dev->addr_list_lock);
>> +	mutex_init(&dev->ethtool->rss_lock);
> 
> Is there a reason to split this from the idr (eventually xarray)
> initialisation above? Surely initialisations for a feature (rss)
> should all be grouped together?

No real reason; I just thought "put locks together" made sense, but
 I guess "put rss stuff together" makes more, can change it.

-e

Re: [RFC PATCH v3 net-next 2/7] net: ethtool: attach an IDR of custom RSS contexts to a netdevice

[Matthew Wilcox]

On Wed, Sep 13, 2023 at 12:22:03PM +0100, Edward Cree wrote:
> On 12/09/2023 17:36, Russell King (Oracle) wrote:
> > On Tue, Sep 12, 2023 at 03:21:37PM +0100, edward.cree@amd.com wrote:
> >> +	struct idr		rss_ctx;
> > 
> > https://docs.kernel.org/core-api/idr.html
> > 
> > "The IDR interface is deprecated; please use the XArray instead."
> 
> IDR is a wrapper around XArray these days, right?

Yes, but a bad one.

> When I looked into the equivalent to use XArray directly it looked much
>  more complicated for flexibility that really isn't needed here.

No, it's no more complex to use.  There are a lot of _other_ things
you can do with it, but every IDR call has an equivalent XArray call.
And as a bonus you get a spinlock protecting you!

> Is there an explanation you can point me at of why this extremely
>  convenient wrapper is deprecated?

Because why have two APIs for the same thing?  One day, I will be finished
with important projects and then I'll go back to eradicating the users
of the IDR.

Re: [RFC PATCH v3 net-next 4/7] net: ethtool: let the core choose RSS context IDs

[Martin Habets]

On Tue, Sep 12, 2023 at 03:21:39PM +0100, edward.cree@amd.com wrote:
> 
> From: Edward Cree <ecree.xilinx@gmail.com>
> 
> Add a new API to create/modify/remove RSS contexts, that passes in the
>  newly-chosen context ID (not as a pointer) rather than leaving the
>  driver to choose it on create.  Also pass in the ctx, allowing drivers
>  to easily use its private data area to store their hardware-specific
>  state.
> Keep the existing .set_rxfh_context API for now as a fallback, but
>  deprecate it.
> 
> Signed-off-by: Edward Cree <ecree.xilinx@gmail.com>
> ---
>  include/linux/ethtool.h | 40 ++++++++++++++++++++++++--
>  net/core/dev.c          | 11 +++++--
>  net/ethtool/ioctl.c     | 64 +++++++++++++++++++++++++++++++----------
>  3 files changed, 94 insertions(+), 21 deletions(-)
> 
> diff --git a/include/linux/ethtool.h b/include/linux/ethtool.h
> index f7317b53ab61..4fa2a7f6ed4c 100644
> --- a/include/linux/ethtool.h
> +++ b/include/linux/ethtool.h
> @@ -747,10 +747,33 @@ struct ethtool_mm_stats {
>   * @get_rxfh_context: Get the contents of the RX flow hash indirection table,
>   *	hash key, and/or hash function assiciated to the given rss context.
>   *	Returns a negative error code or zero.
> - * @set_rxfh_context: Create, remove and configure RSS contexts. Allows setting
> + * @create_rxfh_context: Create a new RSS context with the specified RX flow
> + *	hash indirection table, hash key, and hash function.
> + *	Arguments which are set to %NULL or zero will be populated to
> + *	appropriate defaults by the driver.
> + *	The &struct ethtool_rxfh_context for this context is passed in @ctx;
> + *	note that the indir table, hkey and hfunc are not yet populated as
> + *	of this call.  The driver does not need to update these; the core
> + *	will do so if this op succeeds.
> + *	If the driver provides this method, it must also provide
> + *	@modify_rxfh_context and @remove_rxfh_context.
> + *	Returns a negative error code or zero.
> + * @modify_rxfh_context: Reconfigure the specified RSS context.  Allows setting
>   *	the contents of the RX flow hash indirection table, hash key, and/or
> - *	hash function associated to the given context. Arguments which are set
> - *	to %NULL or zero will remain unchanged.
> + *	hash function associated with the given context.
> + *	Arguments which are set to %NULL or zero will remain unchanged.
> + *	The &struct ethtool_rxfh_context for this context is passed in @ctx;
> + *	note that it will still contain the *old* settings.  The driver does
> + *	not need to update these; the core will do so if this op succeeds.
> + *	Returns a negative error code or zero. An error code must be returned
> + *	if at least one unsupported change was requested.
> + * @remove_rxfh_context: Remove the specified RSS context.
> + *	The &struct ethtool_rxfh_context for this context is passed in @ctx.
> + *	Returns a negative error code or zero.
> + * @set_rxfh_context: Deprecated API to create, remove and configure RSS
> + *	contexts. Allows setting the contents of the RX flow hash indirection
> + *	table, hash key, and/or hash function associated to the given context.
> + *	Arguments which are set to %NULL or zero will remain unchanged.
>   *	Returns a negative error code or zero. An error code must be returned
>   *	if at least one unsupported change was requested.
>   * @get_channels: Get number of channels.
> @@ -901,6 +924,17 @@ struct ethtool_ops {
>  			    const u8 *key, const u8 hfunc);
>  	int	(*get_rxfh_context)(struct net_device *, u32 *indir, u8 *key,
>  				    u8 *hfunc, u32 rss_context);
> +	int	(*create_rxfh_context)(struct net_device *,
> +				       struct ethtool_rxfh_context *ctx,
> +				       const u32 *indir, const u8 *key,
> +				       const u8 hfunc, u32 rss_context);

To return the rss_context this creates shouldn't it use a pointer to
rss_context here?

Matin

> +	int	(*modify_rxfh_context)(struct net_device *,
> +				       struct ethtool_rxfh_context *ctx,
> +				       const u32 *indir, const u8 *key,
> +				       const u8 hfunc, u32 rss_context);
> +	int	(*remove_rxfh_context)(struct net_device *,
> +				       struct ethtool_rxfh_context *ctx,
> +				       u32 rss_context);
>  	int	(*set_rxfh_context)(struct net_device *, const u32 *indir,
>  				    const u8 *key, const u8 hfunc,
>  				    u32 *rss_context, bool delete);
> diff --git a/net/core/dev.c b/net/core/dev.c
> index 4bbb6bda7b7e..6b8e5fd8691b 100644
> --- a/net/core/dev.c
> +++ b/net/core/dev.c
> @@ -10860,15 +10860,20 @@ static void netdev_rss_contexts_free(struct net_device *dev)
>  	struct ethtool_rxfh_context *ctx;
>  	u32 context;
>  
> -	if (!dev->ethtool_ops->set_rxfh_context)
> +	if (!dev->ethtool_ops->create_rxfh_context &&
> +	    !dev->ethtool_ops->set_rxfh_context)
>  		return;
>  	idr_for_each_entry(&dev->ethtool->rss_ctx, ctx, context) {
>  		u32 *indir = ethtool_rxfh_context_indir(ctx);
>  		u8 *key = ethtool_rxfh_context_key(ctx);
>  
>  		idr_remove(&dev->ethtool->rss_ctx, context);
> -		dev->ethtool_ops->set_rxfh_context(dev, indir, key, ctx->hfunc,
> -						   &context, true);
> +		if (dev->ethtool_ops->create_rxfh_context)
> +			dev->ethtool_ops->remove_rxfh_context(dev, ctx, context);
> +		else
> +			dev->ethtool_ops->set_rxfh_context(dev, indir, key,
> +							   ctx->hfunc,
> +							   &context, true);
>  		kfree(ctx);
>  	}
>  }
> diff --git a/net/ethtool/ioctl.c b/net/ethtool/ioctl.c
> index db596b61c6ab..4ce960a5ad4c 100644
> --- a/net/ethtool/ioctl.c
> +++ b/net/ethtool/ioctl.c
> @@ -1274,7 +1274,8 @@ static noinline_for_stack int ethtool_set_rxfh(struct net_device *dev,
>  	if (rxfh.rsvd8[0] || rxfh.rsvd8[1] || rxfh.rsvd8[2] || rxfh.rsvd32)
>  		return -EINVAL;
>  	/* Most drivers don't handle rss_context, check it's 0 as well */
> -	if (rxfh.rss_context && !ops->set_rxfh_context)
> +	if (rxfh.rss_context && !(ops->create_rxfh_context ||
> +				  ops->set_rxfh_context))
>  		return -EOPNOTSUPP;
>  	create = rxfh.rss_context == ETH_RXFH_CONTEXT_ALLOC;
>  
> @@ -1349,8 +1350,28 @@ static noinline_for_stack int ethtool_set_rxfh(struct net_device *dev,
>  		}
>  		ctx->indir_size = dev_indir_size;
>  		ctx->key_size = dev_key_size;
> -		ctx->hfunc = rxfh.hfunc;
>  		ctx->priv_size = ops->rxfh_priv_size;
> +		/* Initialise to an empty context */
> +		ctx->indir_no_change = ctx->key_no_change = 1;
> +		ctx->hfunc = ETH_RSS_HASH_NO_CHANGE;
> +		if (ops->create_rxfh_context) {
> +			int ctx_id;
> +
> +			/* driver uses new API, core allocates ID */
> +			/* if rss_ctx_max_id is not specified (left as 0), it is
> +			 * treated as INT_MAX + 1 by idr_alloc
> +			 */
> +			ctx_id = idr_alloc(&dev->ethtool->rss_ctx, ctx, 1,
> +					   dev->ethtool->rss_ctx_max_id,
> +					   GFP_KERNEL_ACCOUNT);
> +			/* 0 is not allowed, so treat it like an error here */
> +			if (ctx_id <= 0) {
> +				kfree(ctx);
> +				ret = -ENOMEM;
> +				goto out;
> +			}
> +			rxfh.rss_context = ctx_id;
> +		}
>  	} else if (rxfh.rss_context) {
>  		ctx = idr_find(&dev->ethtool->rss_ctx, rxfh.rss_context);
>  		if (!ctx) {
> @@ -1359,15 +1380,34 @@ static noinline_for_stack int ethtool_set_rxfh(struct net_device *dev,
>  		}
>  	}
>  
> -	if (rxfh.rss_context)
> -		ret = ops->set_rxfh_context(dev, indir, hkey, rxfh.hfunc,
> -					    &rxfh.rss_context, delete);
> -	else
> +	if (rxfh.rss_context) {
> +		if (ops->create_rxfh_context) {
> +			if (create)
> +				ret = ops->create_rxfh_context(dev, ctx, indir,
> +							       hkey, rxfh.hfunc,
> +							       rxfh.rss_context);
> +			else if (delete)
> +				ret = ops->remove_rxfh_context(dev, ctx,
> +							       rxfh.rss_context);
> +			else
> +				ret = ops->modify_rxfh_context(dev, ctx, indir,
> +							       hkey, rxfh.hfunc,
> +							       rxfh.rss_context);
> +		} else {
> +			ret = ops->set_rxfh_context(dev, indir, hkey,
> +						    rxfh.hfunc,
> +						    &rxfh.rss_context, delete);
> +		}
> +	} else {
>  		ret = ops->set_rxfh(dev, indir, hkey, rxfh.hfunc);
> +	}
>  	if (ret) {
> -		if (create)
> +		if (create) {
>  			/* failed to create, free our new tracking entry */
> +			if (ops->create_rxfh_context)
> +				idr_remove(&dev->ethtool->rss_ctx, rxfh.rss_context);
>  			kfree(ctx);
> +		}
>  		goto out;
>  	}
>  
> @@ -1383,12 +1423,8 @@ static noinline_for_stack int ethtool_set_rxfh(struct net_device *dev,
>  			dev->priv_flags |= IFF_RXFH_CONFIGURED;
>  	}
>  	/* Update rss_ctx tracking */
> -	if (create) {
> -		/* Ideally this should happen before calling the driver,
> -		 * so that we can fail more cleanly; but we don't have the
> -		 * context ID until the driver picks it, so we have to
> -		 * wait until after.
> -		 */
> +	if (create && !ops->create_rxfh_context) {
> +		/* driver uses old API, it chose context ID */
>  		if (WARN_ON(idr_find(&dev->ethtool->rss_ctx, rxfh.rss_context))) {
>  			/* context ID reused, our tracking is screwed */
>  			kfree(ctx);
> @@ -1398,8 +1434,6 @@ static noinline_for_stack int ethtool_set_rxfh(struct net_device *dev,
>  		WARN_ON(idr_alloc(&dev->ethtool->rss_ctx, ctx, rxfh.rss_context,
>  				  rxfh.rss_context + 1, GFP_KERNEL) !=
>  			rxfh.rss_context);
> -		ctx->indir_no_change = rxfh.indir_size == ETH_RXFH_INDIR_NO_CHANGE;
> -		ctx->key_no_change = !rxfh.key_size;
>  	}
>  	if (delete) {
>  		WARN_ON(idr_remove(&dev->ethtool->rss_ctx, rxfh.rss_context) != ctx);

Re: [RFC PATCH v3 net-next 4/7] net: ethtool: let the core choose RSS context IDs

[Edward Cree]

On 19/09/2023 12:10, Martin Habets wrote:
> On Tue, Sep 12, 2023 at 03:21:39PM +0100, edward.cree@amd.com wrote:
>> +	int	(*create_rxfh_context)(struct net_device *,
>> +				       struct ethtool_rxfh_context *ctx,
>> +				       const u32 *indir, const u8 *key,
>> +				       const u8 hfunc, u32 rss_context);
> 
> To return the rss_context this creates shouldn't it use a pointer to
> rss_context here?

No, the whole point of this new API is that the core, not the
 driver, chooses the value of rss_context.  Does the commit
 message not explain that sufficiently?
(If you look at Patch #7 you'll see that sfc doesn't even use the
 value, though other drivers might if their HW has a fixed set of
 slots for RSS configs.)

-ed

Re: [RFC PATCH v3 net-next 4/7] net: ethtool: let the core choose RSS context IDs

[Martin Habets]

On Tue, Sep 19, 2023 at 03:36:30PM +0100, Edward Cree wrote:
> 
> On 19/09/2023 12:10, Martin Habets wrote:
> > On Tue, Sep 12, 2023 at 03:21:39PM +0100, edward.cree@amd.com wrote:
> >> +	int	(*create_rxfh_context)(struct net_device *,
> >> +				       struct ethtool_rxfh_context *ctx,
> >> +				       const u32 *indir, const u8 *key,
> >> +				       const u8 hfunc, u32 rss_context);
> > 
> > To return the rss_context this creates shouldn't it use a pointer to
> > rss_context here?
> 
> No, the whole point of this new API is that the core, not the
>  driver, chooses the value of rss_context.  Does the commit
>  message not explain that sufficiently?

Your commit describes it correct, but I had my brain wired the wrong
way around. My mistake.

Martin

> (If you look at Patch #7 you'll see that sfc doesn't even use the
>  value, though other drivers might if their HW has a fixed set of
>  slots for RSS configs.)
> 
> -ed