[PATCH net-next 14/15] net: enetc: add PSI-to-VSI link status notification support for VF

[wei.fang@oss.nxp.com]

From: Wei Fang <wei.fang@nxp.com>

Add infrastructure for ENETC v4 VFs to track PF link status changes via
the PSI-to-VSI messaging channel. Two new ops,
vf_reg_link_status_notifier and vf_unreg_link_status_notifier, are added
to enetc_si_ops and wired into enetc_phylink_connect() and enetc_close()
for the phy-less path. The feature is populated only in enetc4_vsi_ops;
rev1 hardware is not affected.

On enetc_open(), the VF sends a REGISTER_LINK_CHANGE_NOTIFIER message to
the PF through the VSI-to-PSI messaging channel. The PF records the VF
in link_status_ms_mask, and immediately sends the current link status so
that the VF carrier reflects reality as soon as the interface comes up.
On every subsequent PF link transition the PF broadcasts a 16-bit
notification to all registered VFs.

On the VF side, a dedicated MSI-X vector handles incoming PSI-to-VSI
messages. The interrupt handler schedules a work item which parses the
notification and updates the carrier state via netif_carrier_on() or
netif_carrier_off() accordingly.

Signed-off-by: Wei Fang <wei.fang@nxp.com>
---
 drivers/net/ethernet/freescale/enetc/enetc.c  |  11 ++
 drivers/net/ethernet/freescale/enetc/enetc.h  |   4 +
 .../net/ethernet/freescale/enetc/enetc_hw.h   |   9 +
 .../net/ethernet/freescale/enetc/enetc_vf.c   | 185 +++++++++++++++++-
 4 files changed, 208 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/freescale/enetc/enetc.c b/drivers/net/ethernet/freescale/enetc/enetc.c
index fdceaf36daa7..a1a8a1551cd8 100644
--- a/drivers/net/ethernet/freescale/enetc/enetc.c
+++ b/drivers/net/ethernet/freescale/enetc/enetc.c
@@ -2892,11 +2892,15 @@ static void enetc_clear_interrupts(struct enetc_ndev_priv *priv)
 static int enetc_phylink_connect(struct net_device *ndev)
 {
 	struct enetc_ndev_priv *priv = netdev_priv(ndev);
+	struct enetc_si *si = priv->si;
 	struct ethtool_keee edata;
 	int err;
 
 	if (!priv->phylink) {
 		/* phy-less mode */
+		if (si->ops->vf_reg_link_status_notifier)
+			return si->ops->vf_reg_link_status_notifier(si);
+
 		netif_carrier_on(ndev);
 		return 0;
 	}
@@ -2968,6 +2972,7 @@ int enetc_open(struct net_device *ndev)
 {
 	struct enetc_ndev_priv *priv = netdev_priv(ndev);
 	struct enetc_bdr_resource *tx_res, *rx_res;
+	struct enetc_si *si = priv->si;
 	bool extended;
 	int err;
 
@@ -3010,6 +3015,8 @@ int enetc_open(struct net_device *ndev)
 err_alloc_tx:
 	if (priv->phylink)
 		phylink_disconnect_phy(priv->phylink);
+	else if (si->ops->vf_unreg_link_status_notifier)
+		si->ops->vf_unreg_link_status_notifier(si);
 err_phy_connect:
 	enetc_free_irqs(priv);
 err_setup_irqs:
@@ -3050,6 +3057,7 @@ EXPORT_SYMBOL_GPL(enetc_stop);
 int enetc_close(struct net_device *ndev)
 {
 	struct enetc_ndev_priv *priv = netdev_priv(ndev);
+	struct enetc_si *si = priv->si;
 
 	enetc_stop(ndev);
 
@@ -3057,6 +3065,9 @@ int enetc_close(struct net_device *ndev)
 		phylink_stop(priv->phylink);
 		phylink_disconnect_phy(priv->phylink);
 	} else {
+		if (si->ops->vf_unreg_link_status_notifier)
+			si->ops->vf_unreg_link_status_notifier(si);
+
 		netif_carrier_off(ndev);
 	}
 
diff --git a/drivers/net/ethernet/freescale/enetc/enetc.h b/drivers/net/ethernet/freescale/enetc/enetc.h
index 24d9f89aee73..1666dfe81cbb 100644
--- a/drivers/net/ethernet/freescale/enetc/enetc.h
+++ b/drivers/net/ethernet/freescale/enetc/enetc.h
@@ -300,6 +300,10 @@ struct enetc_si_ops {
 	int (*set_rss_table)(struct enetc_si *si, const u32 *table, int count);
 	int (*setup_cbdr)(struct enetc_si *si);
 	void (*teardown_cbdr)(struct enetc_si *si);
+
+	/* VSI-specific hooks */
+	int (*vf_reg_link_status_notifier)(struct enetc_si *si);
+	int (*vf_unreg_link_status_notifier)(struct enetc_si *si);
 };
 
 /* PCI IEP device data */
diff --git a/drivers/net/ethernet/freescale/enetc/enetc_hw.h b/drivers/net/ethernet/freescale/enetc/enetc_hw.h
index 62844344ff29..5dc4532607b3 100644
--- a/drivers/net/ethernet/freescale/enetc/enetc_hw.h
+++ b/drivers/net/ethernet/freescale/enetc/enetc_hw.h
@@ -84,6 +84,9 @@ static inline u32 enetc_vsi_set_msize(u32 size)
 #define  PSIMSGSR_MS(n)		BIT((n) + 1) /* n is VF index */
 #define  PSIMSGSR_MC		GENMASK(31, 16)
 
+#define ENETC_VSIMSGRR		0x208
+#define  VSIMSGRR_MC		GENMASK(31, 16)
+
 /* SI statistics */
 #define ENETC_SIROCT	0x300
 #define ENETC_SIRFRM	0x308
@@ -107,6 +110,12 @@ static inline u32 enetc_vsi_set_msize(u32 size)
 #define ENETC_SICAPR0	0x900
 #define ENETC_SICAPR1	0x904
 
+#define ENETC_VSIIER	0xa00
+#define  VSIIER_MRIE	BIT(9)
+
+#define ENETC_VSIIDR	0xa08
+#define  VSIIDR_MR	BIT(9)
+
 #define ENETC_PSIIER	0xa00
 #define ENETC_PSIIDR	0xa08
 
diff --git a/drivers/net/ethernet/freescale/enetc/enetc_vf.c b/drivers/net/ethernet/freescale/enetc/enetc_vf.c
index 418ee98da17d..9cace77110b8 100644
--- a/drivers/net/ethernet/freescale/enetc/enetc_vf.c
+++ b/drivers/net/ethernet/freescale/enetc/enetc_vf.c
@@ -131,6 +131,37 @@ static int enetc_msg_vsi_send(struct enetc_si *si, struct enetc_msg_swbd *msg)
 	return err;
 }
 
+static int enetc_msg_link_status_notifier(struct enetc_si *si, bool reg)
+{
+	struct device *dev = &si->pdev->dev;
+	struct enetc_msg_swbd msg_swbd;
+	u8 cmd_id;
+
+	msg_swbd.size = ALIGN(sizeof(struct enetc_msg_generic),
+			      ENETC_MSG_ALIGN);
+	msg_swbd.vaddr = dma_alloc_coherent(dev, msg_swbd.size,
+					    &msg_swbd.dma, GFP_KERNEL);
+	if (!msg_swbd.vaddr)
+		return -ENOMEM;
+
+	cmd_id = reg ? ENETC_MSG_REGISTER_LINK_CHANGE_NOTIFIER :
+		       ENETC_MSG_UNREGISTER_LINK_CHANGE_NOTIFIER;
+	enetc_msg_fill_common_hdr(&msg_swbd, ENETC_MSG_CLASS_ID_LINK_STATUS,
+				  cmd_id, 0, 0);
+
+	return enetc_msg_vsi_send(si, &msg_swbd);
+}
+
+static int enetc_vf_reg_link_status_notifier(struct enetc_si *si)
+{
+	return enetc_msg_link_status_notifier(si, true);
+}
+
+static int enetc_vf_unreg_link_status_notifier(struct enetc_si *si)
+{
+	return enetc_msg_link_status_notifier(si, false);
+}
+
 static int enetc_msg_vsi_set_primary_mac_addr(struct enetc_ndev_priv *priv,
 					      struct sockaddr *saddr)
 {
@@ -411,6 +442,113 @@ static void enetc_vf_netdev_setup(struct enetc_si *si, struct net_device *ndev,
 	enetc_load_primary_mac_addr(&si->hw, ndev);
 }
 
+static void enetc_vf_enable_mr_int(struct enetc_hw *hw)
+{
+	u32 val = enetc_rd(hw, ENETC_VSIIER) | VSIIER_MRIE;
+
+	enetc_wr(hw, ENETC_VSIIER, val);
+}
+
+static void enetc_vf_disable_mr_int(struct enetc_hw *hw)
+{
+	u32 val = enetc_rd(hw, ENETC_VSIIER) & (~VSIIER_MRIE);
+
+	enetc_wr(hw, ENETC_VSIIER, val);
+}
+
+static void enetc_vf_msg_handle_link_status(struct enetc_si *si, u8 class_code)
+{
+	struct net_device *ndev = si->ndev;
+
+	switch (class_code) {
+	case ENETC_LINK_STATUS_CLASS_CODE_UP:
+		if (!netif_carrier_ok(ndev)) {
+			netif_carrier_on(ndev);
+			netdev_info(ndev, "Link is Up\n");
+		}
+		break;
+	case ENETC_LINK_STATUS_CLASS_CODE_DOWN:
+		if (netif_carrier_ok(ndev)) {
+			netif_carrier_off(ndev);
+			netdev_info(ndev, "Link is Down\n");
+		}
+		break;
+	}
+}
+
+static void enetc_vf_msg_task(struct work_struct *work)
+{
+	struct enetc_si *si = container_of(work, struct enetc_si, msg_task);
+	struct enetc_hw *hw = &si->hw;
+	u8 class_id, class_code;
+	u16 pf_msg;
+
+	pf_msg = FIELD_GET(VSIMSGRR_MC, enetc_rd(hw, ENETC_VSIMSGRR));
+	/* W1C to clear the message received interrupt event */
+	enetc_wr(hw, ENETC_VSIIDR, VSIIDR_MR);
+
+	class_id = FIELD_GET(ENETC_PF_MSG_CLASS_ID, pf_msg);
+	class_code = FIELD_GET(ENETC_PF_MSG_CLASS_CODE, pf_msg);
+
+	switch (class_id) {
+	case ENETC_MSG_CLASS_ID_LINK_STATUS:
+		enetc_vf_msg_handle_link_status(si, class_code);
+		break;
+	default:
+		dev_err(&si->pdev->dev,
+			"Unsupported Message Class ID (0x%02x) from PF\n",
+			class_id);
+	}
+
+	enetc_vf_enable_mr_int(hw);
+}
+
+static irqreturn_t enetc_vf_msg_msix_handler(int irq, void *data)
+{
+	struct enetc_si *si = (struct enetc_si *)data;
+
+	enetc_vf_disable_mr_int(&si->hw);
+	queue_work(si->workqueue, &si->msg_task);
+
+	return IRQ_HANDLED;
+}
+
+static int enetc_vf_register_msg_msix(struct enetc_si *si)
+{
+	int irq, err;
+
+	if (is_enetc_rev1(si))
+		return 0;
+
+	snprintf(si->msg_int_name, sizeof(si->msg_int_name), "%s-pfmsg",
+		 pci_name(si->pdev));
+	irq = pci_irq_vector(si->pdev, ENETC_SI_INT_IDX);
+	err = request_irq(irq, enetc_vf_msg_msix_handler, 0,
+			  si->msg_int_name, si);
+	if (err) {
+		dev_err(&si->pdev->dev,
+			"VF messaging: request_irq() failed!\n");
+		return err;
+	}
+
+	/* set one IRQ entry for PSI-to-VSI messaging */
+	enetc_wr(&si->hw, ENETC_SIMSIVR, ENETC_SI_INT_IDX);
+
+	/* Enable message received interrupt */
+	enetc_vf_enable_mr_int(&si->hw);
+
+	return 0;
+}
+
+static void enetc_vf_free_msg_msix(struct enetc_si *si)
+{
+	if (is_enetc_rev1(si))
+		return;
+
+	enetc_vf_disable_mr_int(&si->hw);
+	free_irq(pci_irq_vector(si->pdev, ENETC_SI_INT_IDX), si);
+}
+
 static const struct enetc_si_ops enetc_vsi_ops = {
 	.get_rss_table = enetc_get_rss_table,
 	.set_rss_table = enetc_set_rss_table,
@@ -423,8 +561,36 @@ static const struct enetc_si_ops enetc4_vsi_ops = {
 	.set_rss_table = enetc4_set_rss_table,
 	.setup_cbdr = enetc4_setup_cbdr,
 	.teardown_cbdr = enetc4_teardown_cbdr,
+	.vf_reg_link_status_notifier = enetc_vf_reg_link_status_notifier,
+	.vf_unreg_link_status_notifier = enetc_vf_unreg_link_status_notifier,
 };
 
+static int enetc_vf_wq_task_init(struct enetc_si *si)
+{
+	char wq_name[24];
+
+	if (is_enetc_rev1(si))
+		return 0;
+
+	snprintf(wq_name, sizeof(wq_name), "enetc-%s", pci_name(si->pdev));
+	si->workqueue = create_singlethread_workqueue(wq_name);
+	if (!si->workqueue)
+		return -ENOMEM;
+
+	INIT_WORK(&si->msg_task, enetc_vf_msg_task);
+
+	return 0;
+}
+
+static void enetc_vf_wq_task_destroy(struct enetc_si *si)
+{
+	if (!si->workqueue)
+		return;
+
+	disable_work_sync(&si->msg_task);
+	destroy_workqueue(si->workqueue);
+}
+
 static int enetc_vf_probe(struct pci_dev *pdev,
 			  const struct pci_device_id *ent)
 {
@@ -489,6 +655,18 @@ static int enetc_vf_probe(struct pci_dev *pdev,
 		goto err_alloc_msix;
 	}
 
+	err = enetc_vf_wq_task_init(si);
+	if (err) {
+		dev_err(&pdev->dev, "Failed to init workqueue\n");
+		goto err_wq_init;
+	}
+
+	err = enetc_vf_register_msg_msix(si);
+	if (err) {
+		dev_err(&pdev->dev, "Failed to register msg irq\n");
+		goto err_register_msg_msix;
+	}
+
 	err = register_netdev(ndev);
 	if (err)
 		goto err_reg_netdev;
@@ -498,6 +676,10 @@ static int enetc_vf_probe(struct pci_dev *pdev,
 	return 0;
 
 err_reg_netdev:
+	enetc_vf_free_msg_msix(si);
+err_register_msg_msix:
+	enetc_vf_wq_task_destroy(si);
+err_wq_init:
 	enetc_free_msix(priv);
 err_config_si:
 err_alloc_msix:
@@ -524,7 +706,8 @@ static void enetc_vf_remove(struct pci_dev *pdev)
 
 	priv = netdev_priv(si->ndev);
 	unregister_netdev(si->ndev);
-
+	enetc_vf_free_msg_msix(si);
+	enetc_vf_wq_task_destroy(si);
 	enetc_free_msix(priv);
 
 	enetc_free_si_resources(priv);
-- 
2.34.1