From: Long Li <longli@microsoft.com>
Date: Thu, 3 Nov 2022 12:16:21 -0700
Subject: net: mana: Handle vport sharing between devices
Patch-mainline: v6.2-rc1
Git-commit: b5c1c9855be3b5b978fde975a63df3cabc273faa
References: bsc#1210741 jsc#PED-4022

For outgoing packets, the PF requires the VF to configure the vport with
corresponding protection domain and doorbell ID for the kernel or user
context. The vport can't be shared between different contexts.

Implement the logic to exclusively take over the vport by either the
Ethernet device or RDMA device.

Reviewed-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: Long Li <longli@microsoft.com>
Link: https://lore.kernel.org/r/1667502990-2559-4-git-send-email-longli@linuxonhyperv.com
Acked-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/net/ethernet/microsoft/mana/mana.h    |    7 +++
 drivers/net/ethernet/microsoft/mana/mana_en.c |   53 +++++++++++++++++++++++++-
 2 files changed, 58 insertions(+), 2 deletions(-)

--- a/drivers/net/ethernet/microsoft/mana/mana.h
+++ b/drivers/net/ethernet/microsoft/mana/mana.h
@@ -380,6 +380,10 @@ struct mana_port_context {
 	mana_handle_t port_handle;
 	mana_handle_t pf_filter_handle;
 
+	/* Mutex for sharing access to vport_use_count */
+	struct mutex vport_mutex;
+	int vport_use_count;
+
 	u16 port_idx;
 
 	bool port_is_up;
@@ -631,4 +635,7 @@ struct mana_tx_package {
 	struct gdma_posted_wqe_info wqe_info;
 };
 
+int mana_cfg_vport(struct mana_port_context *apc, u32 protection_dom_id,
+		   u32 doorbell_pg_id);
+void mana_uncfg_vport(struct mana_port_context *apc);
 #endif /* _MANA_H */
--- a/drivers/net/ethernet/microsoft/mana/mana_en.c
+++ b/drivers/net/ethernet/microsoft/mana/mana_en.c
@@ -644,13 +644,48 @@ static int mana_query_vport_cfg(struct m
 	return 0;
 }
 
-static int mana_cfg_vport(struct mana_port_context *apc, u32 protection_dom_id,
-			  u32 doorbell_pg_id)
+void mana_uncfg_vport(struct mana_port_context *apc)
+{
+	mutex_lock(&apc->vport_mutex);
+	apc->vport_use_count--;
+	WARN_ON(apc->vport_use_count < 0);
+	mutex_unlock(&apc->vport_mutex);
+}
+EXPORT_SYMBOL_NS(mana_uncfg_vport, NET_MANA);
+
+int mana_cfg_vport(struct mana_port_context *apc, u32 protection_dom_id,
+		   u32 doorbell_pg_id)
 {
 	struct mana_config_vport_resp resp = {};
 	struct mana_config_vport_req req = {};
 	int err;
 
+	/* This function is used to program the Ethernet port in the hardware
+	 * table. It can be called from the Ethernet driver or the RDMA driver.
+	 *
+	 * For Ethernet usage, the hardware supports only one active user on a
+	 * physical port. The driver checks on the port usage before programming
+	 * the hardware when creating the RAW QP (RDMA driver) or exposing the
+	 * device to kernel NET layer (Ethernet driver).
+	 *
+	 * Because the RDMA driver doesn't know in advance which QP type the
+	 * user will create, it exposes the device with all its ports. The user
+	 * may not be able to create RAW QP on a port if this port is already
+	 * in used by the Ethernet driver from the kernel.
+	 *
+	 * This physical port limitation only applies to the RAW QP. For RC QP,
+	 * the hardware doesn't have this limitation. The user can create RC
+	 * QPs on a physical port up to the hardware limits independent of the
+	 * Ethernet usage on the same port.
+	 */
+	mutex_lock(&apc->vport_mutex);
+	if (apc->vport_use_count > 0) {
+		mutex_unlock(&apc->vport_mutex);
+		return -EBUSY;
+	}
+	apc->vport_use_count++;
+	mutex_unlock(&apc->vport_mutex);
+
 	mana_gd_init_req_hdr(&req.hdr, MANA_CONFIG_VPORT_TX,
 			     sizeof(req), sizeof(resp));
 	req.vport = apc->port_handle;
@@ -677,9 +712,16 @@ static int mana_cfg_vport(struct mana_po
 
 	apc->tx_shortform_allowed = resp.short_form_allowed;
 	apc->tx_vp_offset = resp.tx_vport_offset;
+
+	netdev_info(apc->ndev, "Configured vPort %llu PD %u DB %u\n",
+		    apc->port_handle, protection_dom_id, doorbell_pg_id);
 out:
+	if (err)
+		mana_uncfg_vport(apc);
+
 	return err;
 }
+EXPORT_SYMBOL_NS(mana_cfg_vport, NET_MANA);
 
 static int mana_cfg_vport_steering(struct mana_port_context *apc,
 				   enum TRI_STATE rx,
@@ -740,6 +782,9 @@ static int mana_cfg_vport_steering(struc
 			   resp.hdr.status);
 		err = -EPROTO;
 	}
+
+	netdev_info(ndev, "Configured steering vPort %llu entries %u\n",
+		    apc->port_handle, num_entries);
 out:
 	kfree(req);
 	return err;
@@ -1808,6 +1853,7 @@ static void mana_destroy_vport(struct ma
 	}
 
 	mana_destroy_txq(apc);
+	mana_uncfg_vport(apc);
 
 	if (gd->gdma_context->is_pf)
 		mana_pf_deregister_hw_vport(apc);
@@ -2080,6 +2126,9 @@ static int mana_probe_port(struct mana_c
 	apc->pf_filter_handle = INVALID_MANA_HANDLE;
 	apc->port_idx = port_idx;
 
+	mutex_init(&apc->vport_mutex);
+	apc->vport_use_count = 0;
+
 	ndev->netdev_ops = &mana_devops;
 	ndev->ethtool_ops = &mana_ethtool_ops;
 	ndev->mtu = ETH_DATA_LEN;