[PATCH v2 2/2] net/nfp: write link speed to control BAR

[Chaoyong He <chaoyong.he@corigine.com>]

From: James Hershaw <james.hershaw@corigine.com>

Due to changes in the firmware for NFPs, firmware will no longer write
the link speed of a port to the control BAR. In line with the behaviour
of the kernel NFP driver, this is now handled by the PMD by reading the
value provided by the NSP in the nfp_eth_table struct within the pf_dev
of the port and subsequently writing this value to the control BAR.

Signed-off-by: James Hershaw <james.hershaw@corigine.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund@corigine.com>
Reviewed-by: Chaoyong He <chaoyong.he@corigine.com>
---
 drivers/net/nfp/nfp_common.c | 104 +++++++++++++++++++++++------------
 drivers/net/nfp/nfp_ctrl.h   |   9 +++
 2 files changed, 77 insertions(+), 36 deletions(-)

diff --git a/drivers/net/nfp/nfp_common.c b/drivers/net/nfp/nfp_common.c
index 5d92b476e2..2261d955c8 100644
--- a/drivers/net/nfp/nfp_common.c
+++ b/drivers/net/nfp/nfp_common.c
@@ -52,6 +52,58 @@
 #include <sys/ioctl.h>
 #include <errno.h>
 
+static const uint32_t nfp_net_link_speed_nfp2rte[] = {
+	[NFP_NET_CFG_STS_LINK_RATE_UNSUPPORTED] = RTE_ETH_SPEED_NUM_NONE,
+	[NFP_NET_CFG_STS_LINK_RATE_UNKNOWN]     = RTE_ETH_SPEED_NUM_NONE,
+	[NFP_NET_CFG_STS_LINK_RATE_1G]          = RTE_ETH_SPEED_NUM_1G,
+	[NFP_NET_CFG_STS_LINK_RATE_10G]         = RTE_ETH_SPEED_NUM_10G,
+	[NFP_NET_CFG_STS_LINK_RATE_25G]         = RTE_ETH_SPEED_NUM_25G,
+	[NFP_NET_CFG_STS_LINK_RATE_40G]         = RTE_ETH_SPEED_NUM_40G,
+	[NFP_NET_CFG_STS_LINK_RATE_50G]         = RTE_ETH_SPEED_NUM_50G,
+	[NFP_NET_CFG_STS_LINK_RATE_100G]        = RTE_ETH_SPEED_NUM_100G,
+};
+
+static uint16_t
+nfp_net_link_speed_rte2nfp(uint16_t speed)
+{
+	uint16_t i;
+
+	for (i = 0; i < RTE_DIM(nfp_net_link_speed_nfp2rte); i++) {
+		if (speed == nfp_net_link_speed_nfp2rte[i])
+			return i;
+	}
+
+	return NFP_NET_CFG_STS_LINK_RATE_UNKNOWN;
+}
+
+static void
+nfp_net_notify_port_speed(struct rte_eth_dev *dev)
+{
+	struct nfp_net_hw *hw;
+	struct nfp_eth_table *eth_table;
+	uint32_t nn_link_status;
+
+	hw = NFP_NET_DEV_PRIVATE_TO_HW(dev->data->dev_private);
+	eth_table = hw->pf_dev->nfp_eth_table;
+
+	/**
+	 * Read the link status from NFP_NET_CFG_STS. If the link is down
+	 * then write the link speed NFP_NET_CFG_STS_LINK_RATE_UNKNOWN to
+	 * NFP_NET_CFG_STS_NSP_LINK_RATE.
+	 */
+	nn_link_status = nn_cfg_readw(hw, NFP_NET_CFG_STS);
+	if ((nn_link_status & NFP_NET_CFG_STS_LINK) == 0) {
+		nn_cfg_writew(hw, NFP_NET_CFG_STS_NSP_LINK_RATE, NFP_NET_CFG_STS_LINK_RATE_UNKNOWN);
+		return;
+	}
+	/**
+	 * Link is up so read the link speed from the eth_table and write to
+	 * NFP_NET_CFG_STS_NSP_LINK_RATE.
+	 */
+	nn_cfg_writew(hw, NFP_NET_CFG_STS_NSP_LINK_RATE,
+		      nfp_net_link_speed_rte2nfp(eth_table->ports[hw->idx].speed));
+}
+
 static int
 __nfp_net_reconfig(struct nfp_net_hw *hw, uint32_t update)
 {
@@ -111,6 +163,9 @@ nfp_net_reconfig(struct nfp_net_hw *hw, uint32_t ctrl, uint32_t update)
 	PMD_DRV_LOG(DEBUG, "nfp_net_reconfig: ctrl=%08x update=%08x",
 		    ctrl, update);
 
+	if (hw->pf_dev != NULL && hw->pf_dev->app_fw_id == NFP_APP_FW_CORE_NIC)
+		nfp_net_notify_port_speed(hw->eth_dev);
+
 	rte_spinlock_lock(&hw->reconfig_lock);
 
 	nn_cfg_writel(hw, NFP_NET_CFG_CTRL, ctrl);
@@ -538,27 +593,15 @@ nfp_net_link_update(struct rte_eth_dev *dev, __rte_unused int wait_to_complete)
 {
 	struct nfp_net_hw *hw;
 	struct rte_eth_link link;
-	struct nfp_eth_table *nfp_eth_table;
-	uint32_t nn_link_status;
-	uint32_t i;
+	uint16_t nn_link_status;
 	int ret;
 
-	static const uint32_t ls_to_ethtool[] = {
-		[NFP_NET_CFG_STS_LINK_RATE_UNSUPPORTED] = RTE_ETH_SPEED_NUM_NONE,
-		[NFP_NET_CFG_STS_LINK_RATE_UNKNOWN]     = RTE_ETH_SPEED_NUM_NONE,
-		[NFP_NET_CFG_STS_LINK_RATE_1G]          = RTE_ETH_SPEED_NUM_1G,
-		[NFP_NET_CFG_STS_LINK_RATE_10G]         = RTE_ETH_SPEED_NUM_10G,
-		[NFP_NET_CFG_STS_LINK_RATE_25G]         = RTE_ETH_SPEED_NUM_25G,
-		[NFP_NET_CFG_STS_LINK_RATE_40G]         = RTE_ETH_SPEED_NUM_40G,
-		[NFP_NET_CFG_STS_LINK_RATE_50G]         = RTE_ETH_SPEED_NUM_50G,
-		[NFP_NET_CFG_STS_LINK_RATE_100G]        = RTE_ETH_SPEED_NUM_100G,
-	};
-
 	PMD_DRV_LOG(DEBUG, "Link update");
 
 	hw = NFP_NET_DEV_PRIVATE_TO_HW(dev->data->dev_private);
 
-	nn_link_status = nn_cfg_readl(hw, NFP_NET_CFG_STS);
+	/* Read link status */
+	nn_link_status = nn_cfg_readw(hw, NFP_NET_CFG_STS);
 
 	memset(&link, 0, sizeof(struct rte_eth_link));
 
@@ -567,28 +610,17 @@ nfp_net_link_update(struct rte_eth_dev *dev, __rte_unused int wait_to_complete)
 
 	link.link_duplex = RTE_ETH_LINK_FULL_DUPLEX;
 
-	if (hw->pf_dev != NULL) {
-		nfp_eth_table = hw->pf_dev->nfp_eth_table;
-		if (nfp_eth_table != NULL) {
-			link.link_speed = nfp_eth_table->ports[hw->idx].speed;
-			for (i = 0; i < RTE_DIM(ls_to_ethtool); i++) {
-				if (ls_to_ethtool[i] == link.link_speed)
-					break;
-			}
-			if (i == RTE_DIM(ls_to_ethtool))
-				link.link_speed = RTE_ETH_SPEED_NUM_NONE;
-		} else {
-			link.link_speed = RTE_ETH_SPEED_NUM_NONE;
-		}
-	} else {
-		nn_link_status = (nn_link_status >> NFP_NET_CFG_STS_LINK_RATE_SHIFT) &
-				NFP_NET_CFG_STS_LINK_RATE_MASK;
+	/**
+	 * Shift and mask nn_link_status so that it is effectively the value
+	 * at offset NFP_NET_CFG_STS_NSP_LINK_RATE.
+	 */
+	nn_link_status = (nn_link_status >> NFP_NET_CFG_STS_LINK_RATE_SHIFT) &
+			 NFP_NET_CFG_STS_LINK_RATE_MASK;
 
-		if (nn_link_status >= RTE_DIM(ls_to_ethtool))
-			link.link_speed = RTE_ETH_SPEED_NUM_NONE;
-		else
-			link.link_speed = ls_to_ethtool[nn_link_status];
-	}
+	if (nn_link_status >= RTE_DIM(nfp_net_link_speed_nfp2rte))
+		link.link_speed = RTE_ETH_SPEED_NUM_NONE;
+	else
+		link.link_speed = nfp_net_link_speed_nfp2rte[nn_link_status];
 
 	ret = rte_eth_linkstatus_set(dev, &link);
 	if (ret == 0) {
diff --git a/drivers/net/nfp/nfp_ctrl.h b/drivers/net/nfp/nfp_ctrl.h
index 75e4458a1b..244048796c 100644
--- a/drivers/net/nfp/nfp_ctrl.h
+++ b/drivers/net/nfp/nfp_ctrl.h
@@ -178,6 +178,15 @@
 #define   NFP_NET_CFG_STS_LINK_RATE_40G           5
 #define   NFP_NET_CFG_STS_LINK_RATE_50G           6
 #define   NFP_NET_CFG_STS_LINK_RATE_100G          7
+
+/*
+ * NSP Link rate is a 16-bit word. It is no longer determined by
+ * firmware, instead it is read from the nfp_eth_table of the
+ * associated pf_dev and written to the NFP_NET_CFG_STS_NSP_LINK_RATE
+ * address by the PMD each time the port is reconfigured.
+ */
+#define NFP_NET_CFG_STS_NSP_LINK_RATE   0x0036
+
 #define NFP_NET_CFG_CAP                 0x0038
 #define NFP_NET_CFG_MAX_TXRINGS         0x003c
 #define NFP_NET_CFG_MAX_RXRINGS         0x0040
-- 
2.39.1