ixgbe/ixgbevf: fix XFRM_ALGO dependency

Based on the original work from Arnd Bergmann.

When XFRM_ALGO is not enabled, the new ixgbe IPsec code produces a
link error:

drivers/net/ethernet/intel/ixgbe/ixgbe_ipsec.o: In function `ixgbe_ipsec_vf_add_sa':
ixgbe_ipsec.c:(.text+0x1266): undefined reference to `xfrm_aead_get_byname'

Simply selecting XFRM_ALGO from here causes circular dependencies, so
to fix it, we probably want this slightly more complex solution that is
similar to what other drivers with XFRM offload do:

A separate Kconfig symbol now controls whether we include the IPsec
offload code. To keep the old behavior, this is left as 'default y'. The
dependency in XFRM_OFFLOAD still causes a circular dependency but is
not actually needed because this symbol is not user visible, so removing
that dependency on top makes it all work.

CC: Arnd Bergmann <arnd@arndb.de>
CC: Shannon Nelson <shannon.nelson@oracle.com>
Fixes: eda0333a ("ixgbe: add VF IPsec management")
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>

drivers/net/ethernet/intel/Kconfig

@@ -200,6 +200,15 @@ config IXGBE_DCB
 
 	  If unsure, say N.
 
+config IXGBE_IPSEC
+	bool "IPSec XFRM cryptography-offload acceleration"
+	depends on IXGBE
+	depends on XFRM_OFFLOAD
+	default y
+	select XFRM_ALGO
+	---help---
+	  Enable support for IPSec offload in ixgbe.ko
+
 config IXGBEVF
 	tristate "Intel(R) 10GbE PCI Express Virtual Function Ethernet support"
 	depends on PCI_MSI
@@ -217,6 +226,15 @@ config IXGBEVF
 	  will be called ixgbevf.  MSI-X interrupt support is required
 	  for this driver to work correctly.
 
+config IXGBEVF_IPSEC
+	bool "IPSec XFRM cryptography-offload acceleration"
+	depends on IXGBEVF
+	depends on XFRM_OFFLOAD
+	default y
+	select XFRM_ALGO
+	---help---
+	  Enable support for IPSec offload in ixgbevf.ko
+
 config I40E
 	tristate "Intel(R) Ethernet Controller XL710 Family support"
 	imply PTP_1588_CLOCK

drivers/net/ethernet/intel/ixgbe/Makefile

@@ -17,4 +17,4 @@ ixgbe-$(CONFIG_IXGBE_DCB) +=  ixgbe_dcb.o ixgbe_dcb_82598.o \
 ixgbe-$(CONFIG_IXGBE_HWMON) += ixgbe_sysfs.o
 ixgbe-$(CONFIG_DEBUG_FS) += ixgbe_debugfs.o
 ixgbe-$(CONFIG_FCOE:m=y) += ixgbe_fcoe.o
-ixgbe-$(CONFIG_XFRM_OFFLOAD) += ixgbe_ipsec.o
+ixgbe-$(CONFIG_IXGBE_IPSEC) += ixgbe_ipsec.o

drivers/net/ethernet/intel/ixgbe/ixgbe.h

@@ -769,9 +769,9 @@ struct ixgbe_adapter {
 #define IXGBE_RSS_KEY_SIZE     40  /* size of RSS Hash Key in bytes */
 	u32 *rss_key;
 
-#ifdef CONFIG_XFRM_OFFLOAD
+#ifdef CONFIG_IXGBE_IPSEC
 	struct ixgbe_ipsec *ipsec;
-#endif /* CONFIG_XFRM_OFFLOAD */
+#endif /* CONFIG_IXGBE_IPSEC */
 
 	/* AF_XDP zero-copy */
 	struct xdp_umem **xsk_umems;
@@ -1008,7 +1008,7 @@ void ixgbe_store_key(struct ixgbe_adapter *adapter);
 void ixgbe_store_reta(struct ixgbe_adapter *adapter);
 s32 ixgbe_negotiate_fc(struct ixgbe_hw *hw, u32 adv_reg, u32 lp_reg,
 		       u32 adv_sym, u32 adv_asm, u32 lp_sym, u32 lp_asm);
-#ifdef CONFIG_XFRM_OFFLOAD
+#ifdef CONFIG_IXGBE_IPSEC
 void ixgbe_init_ipsec_offload(struct ixgbe_adapter *adapter);
 void ixgbe_stop_ipsec_offload(struct ixgbe_adapter *adapter);
 void ixgbe_ipsec_restore(struct ixgbe_adapter *adapter);
@@ -1036,5 +1036,5 @@ static inline int ixgbe_ipsec_vf_add_sa(struct ixgbe_adapter *adapter,
 					u32 *mbuf, u32 vf) { return -EACCES; }
 static inline int ixgbe_ipsec_vf_del_sa(struct ixgbe_adapter *adapter,
 					u32 *mbuf, u32 vf) { return -EACCES; }
-#endif /* CONFIG_XFRM_OFFLOAD */
+#endif /* CONFIG_IXGBE_IPSEC */
 #endif /* _IXGBE_H_ */

drivers/net/ethernet/intel/ixgbe/ixgbe_main.c

@@ -8694,7 +8694,7 @@ netdev_tx_t ixgbe_xmit_frame_ring(struct sk_buff *skb,
 
 #endif /* IXGBE_FCOE */
 
-#ifdef CONFIG_XFRM_OFFLOAD
+#ifdef CONFIG_IXGBE_IPSEC
 	if (skb->sp && !ixgbe_ipsec_tx(tx_ring, first, &ipsec_tx))
 		goto out_drop;
 #endif
@@ -10190,7 +10190,7 @@ ixgbe_features_check(struct sk_buff *skb, struct net_device *dev,
 	 * the TSO, so it's the exception.
 	 */
 	if (skb->encapsulation && !(features & NETIF_F_TSO_MANGLEID)) {
-#ifdef CONFIG_XFRM_OFFLOAD
+#ifdef CONFIG_IXGBE_IPSEC
 		if (!skb->sp)
 #endif
 			features &= ~NETIF_F_TSO;
@@ -10883,7 +10883,7 @@ static int ixgbe_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 	if (hw->mac.type >= ixgbe_mac_82599EB)
 		netdev->features |= NETIF_F_SCTP_CRC;
 
-#ifdef CONFIG_XFRM_OFFLOAD
+#ifdef CONFIG_IXGBE_IPSEC
 #define IXGBE_ESP_FEATURES	(NETIF_F_HW_ESP | \
 				 NETIF_F_HW_ESP_TX_CSUM | \
 				 NETIF_F_GSO_ESP)

drivers/net/ethernet/intel/ixgbevf/Makefile

@@ -10,5 +10,5 @@ ixgbevf-objs := vf.o \
                 mbx.o \
                 ethtool.o \
                 ixgbevf_main.o
-ixgbevf-$(CONFIG_XFRM_OFFLOAD) += ipsec.o
+ixgbevf-$(CONFIG_IXGBEVF_IPSEC) += ipsec.o
 

drivers/net/ethernet/intel/ixgbevf/ixgbevf.h

@@ -459,7 +459,7 @@ int ethtool_ioctl(struct ifreq *ifr);
 
 extern void ixgbevf_write_eitr(struct ixgbevf_q_vector *q_vector);
 
-#ifdef CONFIG_XFRM_OFFLOAD
+#ifdef CONFIG_IXGBEVF_IPSEC
 void ixgbevf_init_ipsec_offload(struct ixgbevf_adapter *adapter);
 void ixgbevf_stop_ipsec_offload(struct ixgbevf_adapter *adapter);
 void ixgbevf_ipsec_restore(struct ixgbevf_adapter *adapter);
@@ -482,7 +482,7 @@ static inline int ixgbevf_ipsec_tx(struct ixgbevf_ring *tx_ring,
 				   struct ixgbevf_tx_buffer *first,
 				   struct ixgbevf_ipsec_tx_data *itd)
 { return 0; }
-#endif /* CONFIG_XFRM_OFFLOAD */
+#endif /* CONFIG_IXGBEVF_IPSEC */
 
 void ixgbe_napi_add_all(struct ixgbevf_adapter *adapter);
 void ixgbe_napi_del_all(struct ixgbevf_adapter *adapter);

drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c

@@ -4150,7 +4150,7 @@ static int ixgbevf_xmit_frame_ring(struct sk_buff *skb,
 	first->tx_flags = tx_flags;
 	first->protocol = vlan_get_protocol(skb);
 
-#ifdef CONFIG_XFRM_OFFLOAD
+#ifdef CONFIG_IXGBEVF_IPSEC
 	if (skb->sp && !ixgbevf_ipsec_tx(tx_ring, first, &ipsec_tx))
 		goto out_drop;
 #endif

net/xfrm/Kconfig

@@ -8,7 +8,6 @@ config XFRM
 
 config XFRM_OFFLOAD
        bool
-       depends on XFRM
 
 config XFRM_ALGO
 	tristate