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>

1 files changed, 50 insertions, 21 deletions

diff --git a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_uld.c b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_uld.c
index 9e3c6b36cde8..0307e9c69a47 100644
--- a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_uld.c
+++ b/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;
+	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)
+				return ret;
+			pr_info("kTLS is disabled. Restrictions on ULD support removed\n");
+		}
+	}
 
-	ret = t4_set_params(adap, adap->mbox, adap->pf, 0, 1, &params, &params);
-	/* if fw returns failure, clear the ktls flag */
-	if (ret)
-		adap->params.crypto &= ~ULP_CRYPTO_KTLS_INLINE;
+	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) {