cxgb4/chcr: Enable ktls settings at run time

Current design enables ktls setting from start, which is not
efficient. Now the feature will be enabled when user demands
TLS offload on any interface.

v1->v2:
- taking ULD module refcount till any single connection exists.
- taking rtnl_lock() before clearing tls_devops.

v2->v3:
- cxgb4 is now registering to tlsdev_ops.
- module refcount inc/dec in chcr.
- refcount is only for connections.
- removed new code from cxgb_set_feature().

v3->v4:
- fixed warning message.
Signed-off-by: Rohit Maheshwari <rohitm@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/crypto/chelsio/chcr_core.c

@@ -33,6 +33,13 @@ static int cpl_fw6_pld_handler(struct adapter *adap, unsigned char *input);
 static void *chcr_uld_add(const struct cxgb4_lld_info *lld);
 static int chcr_uld_state_change(void *handle, enum cxgb4_state state);
 
+#if defined(CONFIG_CHELSIO_TLS_DEVICE)
+static const struct tlsdev_ops chcr_ktls_ops = {
+	.tls_dev_add = chcr_ktls_dev_add,
+	.tls_dev_del = chcr_ktls_dev_del,
+};
+#endif
+
 #ifdef CONFIG_CHELSIO_IPSEC_INLINE
 static void update_netdev_features(void);
 #endif /* CONFIG_CHELSIO_IPSEC_INLINE */
@@ -56,6 +63,9 @@ static struct cxgb4_uld_info chcr_uld_info = {
 #if defined(CONFIG_CHELSIO_IPSEC_INLINE) || defined(CONFIG_CHELSIO_TLS_DEVICE)
 	.tx_handler = chcr_uld_tx_handler,
 #endif /* CONFIG_CHELSIO_IPSEC_INLINE || CONFIG_CHELSIO_TLS_DEVICE */
+#if defined(CONFIG_CHELSIO_TLS_DEVICE)
+	.tlsdev_ops = &chcr_ktls_ops,
+#endif
 };
 
 static void detach_work_fn(struct work_struct *work)
@@ -207,11 +217,6 @@ static void *chcr_uld_add(const struct cxgb4_lld_info *lld)
 	}
 	u_ctx->lldi = *lld;
 	chcr_dev_init(u_ctx);
-
-#ifdef CONFIG_CHELSIO_TLS_DEVICE
-	if (lld->ulp_crypto & ULP_CRYPTO_KTLS_INLINE)
-		chcr_enable_ktls(padap(&u_ctx->dev));
-#endif
 out:
 	return u_ctx;
 }
@@ -348,20 +353,12 @@ static void __exit chcr_crypto_exit(void)
 	list_for_each_entry_safe(u_ctx, tmp, &drv_data.act_dev, entry) {
 		adap = padap(&u_ctx->dev);
 		memset(&adap->chcr_stats, 0, sizeof(adap->chcr_stats));
-#ifdef CONFIG_CHELSIO_TLS_DEVICE
-		if (u_ctx->lldi.ulp_crypto & ULP_CRYPTO_KTLS_INLINE)
-			chcr_disable_ktls(adap);
-#endif
 		list_del(&u_ctx->entry);
 		kfree(u_ctx);
 	}
 	list_for_each_entry_safe(u_ctx, tmp, &drv_data.inact_dev, entry) {
 		adap = padap(&u_ctx->dev);
 		memset(&adap->chcr_stats, 0, sizeof(adap->chcr_stats));
-#ifdef CONFIG_CHELSIO_TLS_DEVICE
-		if (u_ctx->lldi.ulp_crypto & ULP_CRYPTO_KTLS_INLINE)
-			chcr_disable_ktls(adap);
-#endif
 		list_del(&u_ctx->entry);
 		kfree(u_ctx);
 	}

drivers/crypto/chelsio/chcr_core.h

@@ -37,6 +37,7 @@
 #define __CHCR_CORE_H__
 
 #include <crypto/algapi.h>
+#include <net/tls.h>
 #include "t4_hw.h"
 #include "cxgb4.h"
 #include "t4_msg.h"
@@ -223,10 +224,15 @@ int chcr_handle_resp(struct crypto_async_request *req, unsigned char *input,
 int chcr_ipsec_xmit(struct sk_buff *skb, struct net_device *dev);
 void chcr_add_xfrmops(const struct cxgb4_lld_info *lld);
 #ifdef CONFIG_CHELSIO_TLS_DEVICE
-void chcr_enable_ktls(struct adapter *adap);
-void chcr_disable_ktls(struct adapter *adap);
 int chcr_ktls_cpl_act_open_rpl(struct adapter *adap, unsigned char *input);
 int chcr_ktls_cpl_set_tcb_rpl(struct adapter *adap, unsigned char *input);
 int chcr_ktls_xmit(struct sk_buff *skb, struct net_device *dev);
+extern int chcr_ktls_dev_add(struct net_device *netdev, struct sock *sk,
+			     enum tls_offload_ctx_dir direction,
+			     struct tls_crypto_info *crypto_info,
+			     u32 start_offload_tcp_sn);
+extern void chcr_ktls_dev_del(struct net_device *netdev,
+			      struct tls_context *tls_ctx,
+			      enum tls_offload_ctx_dir direction);
 #endif
 #endif /* __CHCR_CORE_H__ */

drivers/crypto/chelsio/chcr_ktls.c

@@ -373,7 +373,7 @@ static int chcr_ktls_mark_tcb_close(struct chcr_ktls_info *tx_info)
  * @tls_cts - tls context.
  * @direction - TX/RX crypto direction
  */
-static void chcr_ktls_dev_del(struct net_device *netdev,
+void chcr_ktls_dev_del(struct net_device *netdev,
 		       struct tls_context *tls_ctx,
 		       enum tls_offload_ctx_dir direction)
 {
@@ -411,6 +411,8 @@ static void chcr_ktls_dev_del(struct net_device *netdev,
 	atomic64_inc(&tx_info->adap->chcr_stats.ktls_tx_connection_close);
 	kvfree(tx_info);
 	tx_ctx->chcr_info = NULL;
+	/* release module refcount */
+	module_put(THIS_MODULE);
 }
 
 /*
@@ -422,7 +424,7 @@ static void chcr_ktls_dev_del(struct net_device *netdev,
  * @direction - TX/RX crypto direction
  * return: SUCCESS/FAILURE.
  */
-static int chcr_ktls_dev_add(struct net_device *netdev, struct sock *sk,
+int chcr_ktls_dev_add(struct net_device *netdev, struct sock *sk,
 		      enum tls_offload_ctx_dir direction,
 		      struct tls_crypto_info *crypto_info,
 		      u32 start_offload_tcp_sn)
@@ -528,6 +530,12 @@ static int chcr_ktls_dev_add(struct net_device *netdev, struct sock *sk,
 	if (ret)
 		goto out2;
 
+	/* Driver shouldn't be removed until any single connection exists */
+	if (!try_module_get(THIS_MODULE)) {
+		ret = -EINVAL;
+		goto out2;
+	}
+
 	atomic64_inc(&adap->chcr_stats.ktls_tx_connection_open);
 	return 0;
 out2:
@@ -537,43 +545,6 @@ static int chcr_ktls_dev_add(struct net_device *netdev, struct sock *sk,
 	return ret;
 }
 
-static const struct tlsdev_ops chcr_ktls_ops = {
-	.tls_dev_add = chcr_ktls_dev_add,
-	.tls_dev_del = chcr_ktls_dev_del,
-};
-
-/*
- * chcr_enable_ktls:  add NETIF_F_HW_TLS_TX flag in all the ports.
- */
-void chcr_enable_ktls(struct adapter *adap)
-{
-	struct net_device *netdev;
-	int i;
-
-	for_each_port(adap, i) {
-		netdev = adap->port[i];
-		netdev->features |= NETIF_F_HW_TLS_TX;
-		netdev->hw_features |= NETIF_F_HW_TLS_TX;
-		netdev->tlsdev_ops = &chcr_ktls_ops;
-	}
-}
-
-/*
- * chcr_disable_ktls:  remove NETIF_F_HW_TLS_TX flag from all the ports.
- */
-void chcr_disable_ktls(struct adapter *adap)
-{
-	struct net_device *netdev;
-	int i;
-
-	for_each_port(adap, i) {
-		netdev = adap->port[i];
-		netdev->features &= ~NETIF_F_HW_TLS_TX;
-		netdev->hw_features &= ~NETIF_F_HW_TLS_TX;
-		netdev->tlsdev_ops = NULL;
-	}
-}
-
 /*
  * chcr_init_tcb_fields:  Initialize tcb fields to handle TCP seq number
  *			  handling.

drivers/crypto/chelsio/chcr_ktls.h

@@ -89,10 +89,15 @@ static inline int chcr_get_first_rx_qid(struct adapter *adap)
 	return u_ctx->lldi.rxq_ids[0];
 }
 
-void chcr_enable_ktls(struct adapter *adap);
-void chcr_disable_ktls(struct adapter *adap);
 int chcr_ktls_cpl_act_open_rpl(struct adapter *adap, unsigned char *input);
 int chcr_ktls_cpl_set_tcb_rpl(struct adapter *adap, unsigned char *input);
 int chcr_ktls_xmit(struct sk_buff *skb, struct net_device *dev);
+int chcr_ktls_dev_add(struct net_device *netdev, struct sock *sk,
+		      enum tls_offload_ctx_dir direction,
+		      struct tls_crypto_info *crypto_info,
+		      u32 start_offload_tcp_sn);
+void chcr_ktls_dev_del(struct net_device *netdev,
+		       struct tls_context *tls_ctx,
+		       enum tls_offload_ctx_dir direction);
 #endif /* CONFIG_CHELSIO_TLS_DEVICE */
 #endif /* __CHCR_KTLS_H__ */

drivers/net/ethernet/chelsio/cxgb4/cxgb4.h

@@ -1099,6 +1099,7 @@ struct adapter {
 
 	/* TC u32 offload */
 	struct cxgb4_tc_u32_table *tc_u32;
+	struct chcr_ktls chcr_ktls;
 	struct chcr_stats_debug chcr_stats;
 
 	/* TC flower offload */
@@ -2060,4 +2061,7 @@ int cxgb_open(struct net_device *dev);
 int cxgb_close(struct net_device *dev);
 void cxgb4_enable_rx(struct adapter *adap, struct sge_rspq *q);
 void cxgb4_quiesce_rx(struct sge_rspq *q);
+#ifdef CONFIG_CHELSIO_TLS_DEVICE
+int cxgb4_set_ktls_feature(struct adapter *adap, bool enable);
+#endif
 #endif /* __CXGB4_H__ */

drivers/net/ethernet/chelsio/cxgb4/cxgb4_debugfs.c

@@ -3491,6 +3491,8 @@ static int chcr_stats_show(struct seq_file *seq, void *v)
 		   atomic_read(&adap->chcr_stats.tls_key));
 #ifdef CONFIG_CHELSIO_TLS_DEVICE
 	seq_puts(seq, "\nChelsio KTLS Crypto Accelerator Stats\n");
+	seq_printf(seq, "Tx TLS offload refcount:          %20u\n",
+		   refcount_read(&adap->chcr_ktls.ktls_refcount));
 	seq_printf(seq, "Tx HW offload contexts added:     %20llu\n",
 		   atomic64_read(&adap->chcr_stats.ktls_tx_ctx));
 	seq_printf(seq, "Tx connection created:            %20llu\n",

drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c

@@ -66,6 +66,9 @@
 #include <linux/crash_dump.h>
 #include <net/udp_tunnel.h>
 #include <net/xfrm.h>
+#if defined(CONFIG_CHELSIO_TLS_DEVICE)
+#include <net/tls.h>
+#endif
 
 #include "cxgb4.h"
 #include "cxgb4_filter.h"
@@ -6064,6 +6067,79 @@ static int cxgb4_iov_configure(struct pci_dev *pdev, int num_vfs)
 }
 #endif /* CONFIG_PCI_IOV */
 
+#if defined(CONFIG_CHELSIO_TLS_DEVICE)
+
+static int cxgb4_ktls_dev_add(struct net_device *netdev, struct sock *sk,
+			      enum tls_offload_ctx_dir direction,
+			      struct tls_crypto_info *crypto_info,
+			      u32 tcp_sn)
+{
+	struct adapter *adap = netdev2adap(netdev);
+	int ret = 0;
+
+	mutex_lock(&uld_mutex);
+	if (!adap->uld[CXGB4_ULD_CRYPTO].handle) {
+		dev_err(adap->pdev_dev, "chcr driver is not loaded\n");
+		ret = -EOPNOTSUPP;
+		goto out_unlock;
+	}
+
+	if (!adap->uld[CXGB4_ULD_CRYPTO].tlsdev_ops) {
+		dev_err(adap->pdev_dev,
+			"chcr driver has no registered tlsdev_ops()\n");
+		ret = -EOPNOTSUPP;
+		goto out_unlock;
+	}
+
+	ret = cxgb4_set_ktls_feature(adap, FW_PARAMS_PARAM_DEV_KTLS_HW_ENABLE);
+	if (ret)
+		goto out_unlock;
+
+	ret = adap->uld[CXGB4_ULD_CRYPTO].tlsdev_ops->tls_dev_add(netdev, sk,
+								  direction,
+								  crypto_info,
+								  tcp_sn);
+	/* if there is a failure, clear the refcount */
+	if (ret)
+		cxgb4_set_ktls_feature(adap,
+				       FW_PARAMS_PARAM_DEV_KTLS_HW_DISABLE);
+out_unlock:
+	mutex_unlock(&uld_mutex);
+	return ret;
+}
+
+static void cxgb4_ktls_dev_del(struct net_device *netdev,
+			       struct tls_context *tls_ctx,
+			       enum tls_offload_ctx_dir direction)
+{
+	struct adapter *adap = netdev2adap(netdev);
+
+	mutex_lock(&uld_mutex);
+	if (!adap->uld[CXGB4_ULD_CRYPTO].handle) {
+		dev_err(adap->pdev_dev, "chcr driver is not loaded\n");
+		goto out_unlock;
+	}
+
+	if (!adap->uld[CXGB4_ULD_CRYPTO].tlsdev_ops) {
+		dev_err(adap->pdev_dev,
+			"chcr driver has no registered tlsdev_ops\n");
+		goto out_unlock;
+	}
+
+	adap->uld[CXGB4_ULD_CRYPTO].tlsdev_ops->tls_dev_del(netdev, tls_ctx,
+							    direction);
+	cxgb4_set_ktls_feature(adap, FW_PARAMS_PARAM_DEV_KTLS_HW_DISABLE);
+
+out_unlock:
+	mutex_unlock(&uld_mutex);
+}
+
+static const struct tlsdev_ops cxgb4_ktls_ops = {
+	.tls_dev_add = cxgb4_ktls_dev_add,
+	.tls_dev_del = cxgb4_ktls_dev_del,
+};
+#endif /* CONFIG_CHELSIO_TLS_DEVICE */
+
 static int init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 {
 	struct net_device *netdev;
@@ -6313,7 +6389,14 @@ static int init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 			netdev->hw_features |= NETIF_F_HIGHDMA;
 		netdev->features |= netdev->hw_features;
 		netdev->vlan_features = netdev->features & VLAN_FEAT;
-
+#if defined(CONFIG_CHELSIO_TLS_DEVICE)
+		if (pi->adapter->params.crypto & FW_CAPS_CONFIG_TLS_HW) {
+			netdev->hw_features |= NETIF_F_HW_TLS_TX;
+			netdev->tlsdev_ops = &cxgb4_ktls_ops;
+			/* initialize the refcount */
+			refcount_set(&pi->adapter->chcr_ktls.ktls_refcount, 0);
+		}
+#endif
 		netdev->priv_flags |= IFF_UNICAST_FLT;
 
 		/* MTU range: 81 - 9600 */

drivers/net/ethernet/chelsio/cxgb4/cxgb4_uld.c

@@ -663,22 +663,64 @@ static int uld_attach(struct adapter *adap, unsigned int uld)
 	return 0;
 }
 
+static bool cxgb4_uld_in_use(struct adapter *adap)
+{
+	const struct tid_info *t = &adap->tids;
+
+	return (atomic_read(&t->conns_in_use) || t->stids_in_use);
+}
+
 #ifdef CONFIG_CHELSIO_TLS_DEVICE
 /* cxgb4_set_ktls_feature: request FW to enable/disable ktls settings.
  * @adap: adapter info
  * @enable: 1 to enable / 0 to disable ktls settings.
  */
-static void cxgb4_set_ktls_feature(struct adapter *adap, bool enable)
+int cxgb4_set_ktls_feature(struct adapter *adap, bool enable)
 {
-	u32 params = (FW_PARAMS_MNEM_V(FW_PARAMS_MNEM_DEV) |
-		      FW_PARAMS_PARAM_X_V(FW_PARAMS_PARAM_DEV_KTLS_TX_HW) |
-		      FW_PARAMS_PARAM_Y_V(enable));
 	int ret = 0;
-
-	ret = t4_set_params(adap, adap->mbox, adap->pf, 0, 1, &params, &params);
-	/* if fw returns failure, clear the ktls flag */
+	u32 params =
+		FW_PARAMS_MNEM_V(FW_PARAMS_MNEM_DEV) |
+		FW_PARAMS_PARAM_X_V(FW_PARAMS_PARAM_DEV_KTLS_HW) |
+		FW_PARAMS_PARAM_Y_V(enable) |
+		FW_PARAMS_PARAM_Z_V(FW_PARAMS_PARAM_DEV_KTLS_HW_USER_ENABLE);
+
+	if (enable) {
+		if (!refcount_read(&adap->chcr_ktls.ktls_refcount)) {
+			/* At this moment if ULD connection are up means, other
+			 * ULD is/are already active, return failure.
+			 */
+			if (cxgb4_uld_in_use(adap)) {
+				dev_warn(adap->pdev_dev,
+					 "ULD connections (tid/stid) active. Can't enable kTLS\n");
+				return -EINVAL;
+			}
+			ret = t4_set_params(adap, adap->mbox, adap->pf,
+					    0, 1, &params, &params);
+			if (ret)
+				return ret;
+			refcount_set(&adap->chcr_ktls.ktls_refcount, 1);
+			pr_info("kTLS has been enabled. Restrictions placed on ULD support\n");
+		} else {
+			/* ktls settings already up, just increment refcount. */
+			refcount_inc(&adap->chcr_ktls.ktls_refcount);
+		}
+	} else {
+		/* return failure if refcount is already 0. */
+		if (!refcount_read(&adap->chcr_ktls.ktls_refcount))
+			return -EINVAL;
+		/* decrement refcount and test, if 0, disable ktls feature,
+		 * else return command success.
+		 */
+		if (refcount_dec_and_test(&adap->chcr_ktls.ktls_refcount)) {
+			ret = t4_set_params(adap, adap->mbox, adap->pf,
+					    0, 1, &params, &params);
 			if (ret)
-		adap->params.crypto &= ~ULP_CRYPTO_KTLS_INLINE;
+				return ret;
+			pr_info("kTLS is disabled. Restrictions on ULD support removed\n");
+		}
+	}
+
+	return ret;
 }
 #endif
 
@@ -706,12 +748,6 @@ static void cxgb4_uld_alloc_resources(struct adapter *adap,
 	}
 	if (adap->flags & CXGB4_FULL_INIT_DONE)
 		enable_rx_uld(adap, type);
-#ifdef CONFIG_CHELSIO_TLS_DEVICE
-	/* send mbox to enable ktls related settings. */
-	if (type == CXGB4_ULD_CRYPTO &&
-	    (adap->params.crypto & FW_CAPS_CONFIG_TX_TLS_HW))
-		cxgb4_set_ktls_feature(adap, 1);
-#endif
 	if (adap->uld[type].add)
 		goto free_irq;
 	ret = setup_sge_txq_uld(adap, type, p);
@@ -805,13 +841,6 @@ int cxgb4_unregister_uld(enum cxgb4_uld type)
 			continue;
 
 		cxgb4_shutdown_uld_adapter(adap, type);
-
-#ifdef CONFIG_CHELSIO_TLS_DEVICE
-		/* send mbox to disable ktls related settings. */
-		if (type == CXGB4_ULD_CRYPTO &&
-		    (adap->params.crypto & FW_CAPS_CONFIG_TX_TLS_HW))
-			cxgb4_set_ktls_feature(adap, 0);
-#endif
 	}
 
 	list_for_each_entry_safe(uld_entry, tmp, &uld_list, list_node) {

drivers/net/ethernet/chelsio/cxgb4/cxgb4_uld.h

@@ -268,6 +268,10 @@ struct filter_ctx {
 	u32 tid;			/* to store tid */
 };
 
+struct chcr_ktls {
+	refcount_t ktls_refcount;
+};
+
 struct ch_filter_specification;
 
 int cxgb4_get_free_ftid(struct net_device *dev, u8 family, bool hash_en,
@@ -464,6 +468,9 @@ struct cxgb4_uld_info {
 			      struct napi_struct *napi);
 	void (*lro_flush)(struct t4_lro_mgr *);
 	int (*tx_handler)(struct sk_buff *skb, struct net_device *dev);
+#if IS_ENABLED(CONFIG_TLS_DEVICE)
+	const struct tlsdev_ops *tlsdev_ops;
+#endif
 };
 
 void cxgb4_uld_enable(struct adapter *adap);

drivers/net/ethernet/chelsio/cxgb4/t4fw_api.h

@@ -1205,7 +1205,7 @@ enum fw_caps_config_crypto {
 	FW_CAPS_CONFIG_CRYPTO_LOOKASIDE = 0x00000001,
 	FW_CAPS_CONFIG_TLS_INLINE = 0x00000002,
 	FW_CAPS_CONFIG_IPSEC_INLINE = 0x00000004,
-	FW_CAPS_CONFIG_TX_TLS_HW = 0x00000008,
+	FW_CAPS_CONFIG_TLS_HW = 0x00000008,
 };
 
 enum fw_caps_config_fcoe {
@@ -1329,7 +1329,7 @@ enum fw_params_param_dev {
 	FW_PARAMS_PARAM_DEV_DBQ_TIMERTICK = 0x2A,
 	FW_PARAMS_PARAM_DEV_NUM_TM_CLASS = 0x2B,
 	FW_PARAMS_PARAM_DEV_FILTER = 0x2E,
-	FW_PARAMS_PARAM_DEV_KTLS_TX_HW = 0x31,
+	FW_PARAMS_PARAM_DEV_KTLS_HW = 0x31,
 };
 
 /*
@@ -1412,6 +1412,12 @@ enum fw_params_param_dmaq {
 	FW_PARAMS_PARAM_DMAQ_CONM_CTXT = 0x20,
 };
 
+enum fw_params_param_dev_ktls_hw {
+	FW_PARAMS_PARAM_DEV_KTLS_HW_DISABLE      = 0x00,
+	FW_PARAMS_PARAM_DEV_KTLS_HW_ENABLE       = 0x01,
+	FW_PARAMS_PARAM_DEV_KTLS_HW_USER_ENABLE  = 0x01,
+};
+
 enum fw_params_param_dev_phyfw {
 	FW_PARAMS_PARAM_DEV_PHYFW_DOWNLOAD = 0x00,
 	FW_PARAMS_PARAM_DEV_PHYFW_VERSION = 0x01,