sfc: Make most filter operations NIC-type-specific

Aside from accelerated RFS, there is almost nothing that can be shared
between the filter table implementations for the Falcon architecture
and EF10.

Move the few shared functions into efx.c and rx.c and the rest into
farch.c.  Introduce efx_nic_type operations for the implementation and
inline wrapper functions that call these.
Signed-off-by: NBen Hutchings <bhutchings@solarflare.com>

drivers/net/ethernet/sfc/Makefile

 sfc-y			+= efx.o nic.o farch.o falcon.o siena.o tx.o rx.o \
-			   filter.o \
 			   selftest.o ethtool.o qt202x_phy.o mdio_10g.o \
 			   tenxpress.o txc43128_phy.o falcon_boards.o \
 			   mcdi.o mcdi_port.o mcdi_mon.o ptp.o

drivers/net/ethernet/sfc/efx.c

@@ -611,7 +611,7 @@ static void efx_start_datapath(struct efx_nic *efx)
 
 	/* RX filters also have scatter-enabled flags */
 	if (efx->rx_scatter != old_rx_scatter)
-		efx_filter_update_rx_scatter(efx);
+		efx->type->filter_update_rx_scatter(efx);
 
 	/* We must keep at least one descriptor in a TX ring empty.
 	 * We could avoid this when the queue size does not exactly
@@ -1499,6 +1499,44 @@ static void efx_remove_nic(struct efx_nic *efx)
 	efx->type->remove(efx);
 }
 
+static int efx_probe_filters(struct efx_nic *efx)
+{
+	int rc;
+
+	spin_lock_init(&efx->filter_lock);
+
+	rc = efx->type->filter_table_probe(efx);
+	if (rc)
+		return rc;
+
+#ifdef CONFIG_RFS_ACCEL
+	if (efx->type->offload_features & NETIF_F_NTUPLE) {
+		efx->rps_flow_id = kcalloc(efx->type->max_rx_ip_filters,
+					   sizeof(*efx->rps_flow_id),
+					   GFP_KERNEL);
+		if (!efx->rps_flow_id) {
+			efx->type->filter_table_remove(efx);
+			return -ENOMEM;
+		}
+	}
+#endif
+
+	return 0;
+}
+
+static void efx_remove_filters(struct efx_nic *efx)
+{
+#ifdef CONFIG_RFS_ACCEL
+	kfree(efx->rps_flow_id);
+#endif
+	efx->type->filter_table_remove(efx);
+}
+
+static void efx_restore_filters(struct efx_nic *efx)
+{
+	efx->type->filter_table_restore(efx);
+}
+
 /**************************************************************************
  *
  * NIC startup/shutdown

drivers/net/ethernet/sfc/efx.h

@@ -68,27 +68,92 @@ extern void efx_schedule_slow_fill(struct efx_rx_queue *rx_queue);
 #define EFX_TXQ_MIN_ENT(efx)	(2 * efx_tx_max_skb_descs(efx))
 
 /* Filters */
-extern int efx_probe_filters(struct efx_nic *efx);
-extern void efx_restore_filters(struct efx_nic *efx);
-extern void efx_remove_filters(struct efx_nic *efx);
-extern void efx_filter_update_rx_scatter(struct efx_nic *efx);
-extern s32 efx_filter_insert_filter(struct efx_nic *efx,
-				    struct efx_filter_spec *spec,
-				    bool replace);
-extern int efx_filter_remove_id_safe(struct efx_nic *efx,
-				     enum efx_filter_priority priority,
-				     u32 filter_id);
-extern int efx_filter_get_filter_safe(struct efx_nic *efx,
-				      enum efx_filter_priority priority,
-				      u32 filter_id, struct efx_filter_spec *);
-extern void efx_filter_clear_rx(struct efx_nic *efx,
-				enum efx_filter_priority priority);
-extern u32 efx_filter_count_rx_used(struct efx_nic *efx,
-				    enum efx_filter_priority priority);
-extern u32 efx_filter_get_rx_id_limit(struct efx_nic *efx);
-extern s32 efx_filter_get_rx_ids(struct efx_nic *efx,
-				 enum efx_filter_priority priority,
-				 u32 *buf, u32 size);
+
+/**
+ * efx_filter_insert_filter - add or replace a filter
+ * @efx: NIC in which to insert the filter
+ * @spec: Specification for the filter
+ * @replace_equal: Flag for whether the specified filter may replace an
+ *	existing filter with equal priority
+ *
+ * On success, return the filter ID.
+ * On failure, return a negative error code.
+ *
+ * If an existing filter has equal match values to the new filter
+ * spec, then the new filter might replace it, depending on the
+ * relative priorities.  If the existing filter has lower priority, or
+ * if @replace_equal is set and it has equal priority, then it is
+ * replaced.  Otherwise the function fails, returning -%EPERM if
+ * the existing filter has higher priority or -%EEXIST if it has
+ * equal priority.
+ */
+static inline s32 efx_filter_insert_filter(struct efx_nic *efx,
+					   struct efx_filter_spec *spec,
+					   bool replace_equal)
+{
+	return efx->type->filter_insert(efx, spec, replace_equal);
+}
+
+/**
+ * efx_filter_remove_id_safe - remove a filter by ID, carefully
+ * @efx: NIC from which to remove the filter
+ * @priority: Priority of filter, as passed to @efx_filter_insert_filter
+ * @filter_id: ID of filter, as returned by @efx_filter_insert_filter
+ *
+ * This function will range-check @filter_id, so it is safe to call
+ * with a value passed from userland.
+ */
+static inline int efx_filter_remove_id_safe(struct efx_nic *efx,
+					    enum efx_filter_priority priority,
+					    u32 filter_id)
+{
+	return efx->type->filter_remove_safe(efx, priority, filter_id);
+}
+
+/**
+ * efx_filter_get_filter_safe - retrieve a filter by ID, carefully
+ * @efx: NIC from which to remove the filter
+ * @priority: Priority of filter, as passed to @efx_filter_insert_filter
+ * @filter_id: ID of filter, as returned by @efx_filter_insert_filter
+ * @spec: Buffer in which to store filter specification
+ *
+ * This function will range-check @filter_id, so it is safe to call
+ * with a value passed from userland.
+ */
+static inline int
+efx_filter_get_filter_safe(struct efx_nic *efx,
+			   enum efx_filter_priority priority,
+			   u32 filter_id, struct efx_filter_spec *spec)
+{
+	return efx->type->filter_get_safe(efx, priority, filter_id, spec);
+}
+
+/**
+ * efx_farch_filter_clear_rx - remove RX filters by priority
+ * @efx: NIC from which to remove the filters
+ * @priority: Maximum priority to remove
+ */
+static inline void efx_filter_clear_rx(struct efx_nic *efx,
+				       enum efx_filter_priority priority)
+{
+	return efx->type->filter_clear_rx(efx, priority);
+}
+
+static inline u32 efx_filter_count_rx_used(struct efx_nic *efx,
+					   enum efx_filter_priority priority)
+{
+	return efx->type->filter_count_rx_used(efx, priority);
+}
+static inline u32 efx_filter_get_rx_id_limit(struct efx_nic *efx)
+{
+	return efx->type->filter_get_rx_id_limit(efx);
+}
+static inline s32 efx_filter_get_rx_ids(struct efx_nic *efx,
+					enum efx_filter_priority priority,
+					u32 *buf, u32 size)
+{
+	return efx->type->filter_get_rx_ids(efx, priority, buf, size);
+}
 #ifdef CONFIG_RFS_ACCEL
 extern int efx_filter_rfs(struct net_device *net_dev, const struct sk_buff *skb,
 			  u16 rxq_index, u32 flow_id);

drivers/net/ethernet/sfc/falcon.c

@@ -2400,6 +2400,21 @@ const struct efx_nic_type falcon_a1_nic_type = {
 	.ev_read_ack = efx_farch_ev_read_ack,
 	.ev_test_generate = efx_farch_ev_test_generate,
 
+	/* We don't expose the filter table on Falcon A1 as it is not
+	 * mapped into function 0, but these implementations still
+	 * work with a degenerate case of all tables set to size 0.
+	 */
+	.filter_table_probe = efx_farch_filter_table_probe,
+	.filter_table_restore = efx_farch_filter_table_restore,
+	.filter_table_remove = efx_farch_filter_table_remove,
+	.filter_insert = efx_farch_filter_insert,
+	.filter_remove_safe = efx_farch_filter_remove_safe,
+	.filter_get_safe = efx_farch_filter_get_safe,
+	.filter_clear_rx = efx_farch_filter_clear_rx,
+	.filter_count_rx_used = efx_farch_filter_count_rx_used,
+	.filter_get_rx_id_limit = efx_farch_filter_get_rx_id_limit,
+	.filter_get_rx_ids = efx_farch_filter_get_rx_ids,
+
 	.revision = EFX_REV_FALCON_A1,
 	.txd_ptr_tbl_base = FR_AA_TX_DESC_PTR_TBL_KER,
 	.rxd_ptr_tbl_base = FR_AA_RX_DESC_PTR_TBL_KER,
@@ -2468,6 +2483,21 @@ const struct efx_nic_type falcon_b0_nic_type = {
 	.ev_process = efx_farch_ev_process,
 	.ev_read_ack = efx_farch_ev_read_ack,
 	.ev_test_generate = efx_farch_ev_test_generate,
+	.filter_table_probe = efx_farch_filter_table_probe,
+	.filter_table_restore = efx_farch_filter_table_restore,
+	.filter_table_remove = efx_farch_filter_table_remove,
+	.filter_update_rx_scatter = efx_farch_filter_update_rx_scatter,
+	.filter_insert = efx_farch_filter_insert,
+	.filter_remove_safe = efx_farch_filter_remove_safe,
+	.filter_get_safe = efx_farch_filter_get_safe,
+	.filter_clear_rx = efx_farch_filter_clear_rx,
+	.filter_count_rx_used = efx_farch_filter_count_rx_used,
+	.filter_get_rx_id_limit = efx_farch_filter_get_rx_id_limit,
+	.filter_get_rx_ids = efx_farch_filter_get_rx_ids,
+#ifdef CONFIG_RFS_ACCEL
+	.filter_rfs_insert = efx_farch_filter_rfs_insert,
+	.filter_rfs_expire_one = efx_farch_filter_rfs_expire_one,
+#endif
 
 	.revision = EFX_REV_FALCON_B0,
 	.txd_ptr_tbl_base = FR_BZ_TX_DESC_PTR_TBL,
@@ -2483,5 +2513,6 @@ const struct efx_nic_type falcon_b0_nic_type = {
 	.timer_period_max =  1 << FRF_AB_TC_TIMER_VAL_WIDTH,
 	.offload_features = NETIF_F_IP_CSUM | NETIF_F_RXHASH | NETIF_F_NTUPLE,
 	.mcdi_max_ver = -1,
+	.max_rx_ip_filters = FR_BZ_RX_FILTER_TBL0_ROWS,
 };
 

drivers/net/ethernet/sfc/net_driver.h

@@ -30,6 +30,7 @@
 
 #include "enum.h"
 #include "bitfield.h"
+#include "filter.h"
 
 /**************************************************************************
  *
@@ -1025,6 +1026,24 @@ static inline unsigned int efx_port_num(struct efx_nic *efx)
  * @ev_process: Process events for a queue, up to the given NAPI quota
  * @ev_read_ack: Acknowledge read events on a queue, rearming its IRQ
  * @ev_test_generate: Generate a test event
+ * @filter_table_probe: Probe filter capabilities and set up filter software state
+ * @filter_table_restore: Restore filters removed from hardware
+ * @filter_table_remove: Remove filters from hardware and tear down software state
+ * @filter_update_rx_scatter: Update filters after change to rx scatter setting
+ * @filter_insert: add or replace a filter
+ * @filter_remove_safe: remove a filter by ID, carefully
+ * @filter_get_safe: retrieve a filter by ID, carefully
+ * @filter_clear_rx: remove RX filters by priority
+ * @filter_count_rx_used: Get the number of filters in use at a given priority
+ * @filter_get_rx_id_limit: Get maximum value of a filter id, plus 1
+ * @filter_get_rx_ids: Get list of RX filters at a given priority
+ * @filter_rfs_insert: Add or replace a filter for RFS.  This must be
+ *	atomic.  The hardware change may be asynchronous but should
+ *	not be delayed for long.  It may fail if this can't be done
+ *	atomically.
+ * @filter_rfs_expire_one: Consider expiring a filter inserted for RFS.
+ *	This must check whether the specified table entry is used by RFS
+ *	and that rps_may_expire_flow() returns true for it.
  * @revision: Hardware architecture revision
  * @txd_ptr_tbl_base: TX descriptor ring base address
  * @rxd_ptr_tbl_base: RX descriptor ring base address
@@ -1102,6 +1121,32 @@ struct efx_nic_type {
 	int (*ev_process)(struct efx_channel *channel, int quota);
 	void (*ev_read_ack)(struct efx_channel *channel);
 	void (*ev_test_generate)(struct efx_channel *channel);
+	int (*filter_table_probe)(struct efx_nic *efx);
+	void (*filter_table_restore)(struct efx_nic *efx);
+	void (*filter_table_remove)(struct efx_nic *efx);
+	void (*filter_update_rx_scatter)(struct efx_nic *efx);
+	s32 (*filter_insert)(struct efx_nic *efx,
+			     struct efx_filter_spec *spec, bool replace);
+	int (*filter_remove_safe)(struct efx_nic *efx,
+				  enum efx_filter_priority priority,
+				  u32 filter_id);
+	int (*filter_get_safe)(struct efx_nic *efx,
+			       enum efx_filter_priority priority,
+			       u32 filter_id, struct efx_filter_spec *);
+	void (*filter_clear_rx)(struct efx_nic *efx,
+				enum efx_filter_priority priority);
+	u32 (*filter_count_rx_used)(struct efx_nic *efx,
+				    enum efx_filter_priority priority);
+	u32 (*filter_get_rx_id_limit)(struct efx_nic *efx);
+	s32 (*filter_get_rx_ids)(struct efx_nic *efx,
+				 enum efx_filter_priority priority,
+				 u32 *buf, u32 size);
+#ifdef CONFIG_RFS_ACCEL
+	s32 (*filter_rfs_insert)(struct efx_nic *efx,
+				 struct efx_filter_spec *spec);
+	bool (*filter_rfs_expire_one)(struct efx_nic *efx, u32 flow_id,
+				      unsigned int index);
+#endif
 
 	int revision;
 	unsigned int txd_ptr_tbl_base;
@@ -1117,6 +1162,7 @@ struct efx_nic_type {
 	unsigned int timer_period_max;
 	netdev_features_t offload_features;
 	int mcdi_max_ver;
+	unsigned int max_rx_ip_filters;
 };
 
 /**************************************************************************

drivers/net/ethernet/sfc/nic.h

@@ -404,6 +404,34 @@ extern int efx_farch_ev_process(struct efx_channel *channel, int quota);
 extern void efx_farch_ev_read_ack(struct efx_channel *channel);
 extern void efx_farch_ev_test_generate(struct efx_channel *channel);
 
+/* Falcon/Siena filter operations */
+extern int efx_farch_filter_table_probe(struct efx_nic *efx);
+extern void efx_farch_filter_table_restore(struct efx_nic *efx);
+extern void efx_farch_filter_table_remove(struct efx_nic *efx);
+extern void efx_farch_filter_update_rx_scatter(struct efx_nic *efx);
+extern s32 efx_farch_filter_insert(struct efx_nic *efx,
+				   struct efx_filter_spec *spec, bool replace);
+extern int efx_farch_filter_remove_safe(struct efx_nic *efx,
+					enum efx_filter_priority priority,
+					u32 filter_id);
+extern int efx_farch_filter_get_safe(struct efx_nic *efx,
+				     enum efx_filter_priority priority,
+				     u32 filter_id, struct efx_filter_spec *);
+extern void efx_farch_filter_clear_rx(struct efx_nic *efx,
+				      enum efx_filter_priority priority);
+extern u32 efx_farch_filter_count_rx_used(struct efx_nic *efx,
+					  enum efx_filter_priority priority);
+extern u32 efx_farch_filter_get_rx_id_limit(struct efx_nic *efx);
+extern s32 efx_farch_filter_get_rx_ids(struct efx_nic *efx,
+				       enum efx_filter_priority priority,
+				       u32 *buf, u32 size);
+#ifdef CONFIG_RFS_ACCEL
+extern s32 efx_farch_filter_rfs_insert(struct efx_nic *efx,
+				       struct efx_filter_spec *spec);
+extern bool efx_farch_filter_rfs_expire_one(struct efx_nic *efx, u32 flow_id,
+					    unsigned int index);
+#endif
+
 extern bool efx_nic_event_present(struct efx_channel *channel);
 
 /* Some statistics are computed as A - B where A and B each increase

drivers/net/ethernet/sfc/rx.c

@@ -21,6 +21,7 @@
 #include <net/checksum.h>
 #include "net_driver.h"
 #include "efx.h"
+#include "filter.h"
 #include "nic.h"
 #include "selftest.h"
 #include "workarounds.h"
@@ -802,3 +803,96 @@ module_param(rx_refill_threshold, uint, 0444);
 MODULE_PARM_DESC(rx_refill_threshold,
 		 "RX descriptor ring refill threshold (%)");
 
+#ifdef CONFIG_RFS_ACCEL
+
+int efx_filter_rfs(struct net_device *net_dev, const struct sk_buff *skb,
+		   u16 rxq_index, u32 flow_id)
+{
+	struct efx_nic *efx = netdev_priv(net_dev);
+	struct efx_channel *channel;
+	struct efx_filter_spec spec;
+	const struct iphdr *ip;
+	const __be16 *ports;
+	int nhoff;
+	int rc;
+
+	nhoff = skb_network_offset(skb);
+
+	if (skb->protocol == htons(ETH_P_8021Q)) {
+		EFX_BUG_ON_PARANOID(skb_headlen(skb) <
+				    nhoff + sizeof(struct vlan_hdr));
+		if (((const struct vlan_hdr *)skb->data + nhoff)->
+		    h_vlan_encapsulated_proto != htons(ETH_P_IP))
+			return -EPROTONOSUPPORT;
+
+		/* This is IP over 802.1q VLAN.  We can't filter on the
+		 * IP 5-tuple and the vlan together, so just strip the
+		 * vlan header and filter on the IP part.
+		 */
+		nhoff += sizeof(struct vlan_hdr);
+	} else if (skb->protocol != htons(ETH_P_IP)) {
+		return -EPROTONOSUPPORT;
+	}
+
+	/* RFS must validate the IP header length before calling us */
+	EFX_BUG_ON_PARANOID(skb_headlen(skb) < nhoff + sizeof(*ip));
+	ip = (const struct iphdr *)(skb->data + nhoff);
+	if (ip_is_fragment(ip))
+		return -EPROTONOSUPPORT;
+	EFX_BUG_ON_PARANOID(skb_headlen(skb) < nhoff + 4 * ip->ihl + 4);
+	ports = (const __be16 *)(skb->data + nhoff + 4 * ip->ihl);
+
+	efx_filter_init_rx(&spec, EFX_FILTER_PRI_HINT,
+			   efx->rx_scatter ? EFX_FILTER_FLAG_RX_SCATTER : 0,
+			   rxq_index);
+	rc = efx_filter_set_ipv4_full(&spec, ip->protocol,
+				      ip->daddr, ports[1], ip->saddr, ports[0]);
+	if (rc)
+		return rc;
+
+	rc = efx->type->filter_rfs_insert(efx, &spec);
+	if (rc < 0)
+		return rc;
+
+	/* Remember this so we can check whether to expire the filter later */
+	efx->rps_flow_id[rc] = flow_id;
+	channel = efx_get_channel(efx, skb_get_rx_queue(skb));
+	++channel->rfs_filters_added;
+
+	netif_info(efx, rx_status, efx->net_dev,
+		   "steering %s %pI4:%u:%pI4:%u to queue %u [flow %u filter %d]\n",
+		   (ip->protocol == IPPROTO_TCP) ? "TCP" : "UDP",
+		   &ip->saddr, ntohs(ports[0]), &ip->daddr, ntohs(ports[1]),
+		   rxq_index, flow_id, rc);
+
+	return rc;
+}
+
+bool __efx_filter_rfs_expire(struct efx_nic *efx, unsigned int quota)
+{
+	bool (*expire_one)(struct efx_nic *efx, u32 flow_id, unsigned int index);
+	unsigned int index, size;
+	u32 flow_id;
+
+	if (!spin_trylock_bh(&efx->filter_lock))
+		return false;
+
+	expire_one = efx->type->filter_rfs_expire_one;
+	index = efx->rps_expire_index;
+	size = efx->type->max_rx_ip_filters;
+	while (quota--) {
+		flow_id = efx->rps_flow_id[index];
+		if (expire_one(efx, flow_id, index))
+			netif_info(efx, rx_status, efx->net_dev,
+				   "expired filter %d [flow %u]\n",
+				   index, flow_id);
+		if (++index == size)
+			index = 0;
+	}
+	efx->rps_expire_index = index;
+
+	spin_unlock_bh(&efx->filter_lock);
+	return true;
+}
+
+#endif /* CONFIG_RFS_ACCEL */

drivers/net/ethernet/sfc/siena.c

@@ -736,6 +736,21 @@ const struct efx_nic_type siena_a0_nic_type = {
 	.ev_process = efx_farch_ev_process,
 	.ev_read_ack = efx_farch_ev_read_ack,
 	.ev_test_generate = efx_farch_ev_test_generate,
+	.filter_table_probe = efx_farch_filter_table_probe,
+	.filter_table_restore = efx_farch_filter_table_restore,
+	.filter_table_remove = efx_farch_filter_table_remove,
+	.filter_update_rx_scatter = efx_farch_filter_update_rx_scatter,
+	.filter_insert = efx_farch_filter_insert,
+	.filter_remove_safe = efx_farch_filter_remove_safe,
+	.filter_get_safe = efx_farch_filter_get_safe,
+	.filter_clear_rx = efx_farch_filter_clear_rx,
+	.filter_count_rx_used = efx_farch_filter_count_rx_used,
+	.filter_get_rx_id_limit = efx_farch_filter_get_rx_id_limit,
+	.filter_get_rx_ids = efx_farch_filter_get_rx_ids,
+#ifdef CONFIG_RFS_ACCEL
+	.filter_rfs_insert = efx_farch_filter_rfs_insert,
+	.filter_rfs_expire_one = efx_farch_filter_rfs_expire_one,
+#endif
 
 	.revision = EFX_REV_SIENA_A0,
 	.txd_ptr_tbl_base = FR_BZ_TX_DESC_PTR_TBL,
@@ -752,4 +767,5 @@ const struct efx_nic_type siena_a0_nic_type = {
 	.offload_features = (NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM |
 			     NETIF_F_RXHASH | NETIF_F_NTUPLE),
 	.mcdi_max_ver = 1,
+	.max_rx_ip_filters = FR_BZ_RX_FILTER_TBL0_ROWS,
 };