bnxt_en: Add auxiliary driver support

Add auxiliary driver support.
An auxiliary device will be created if the hardware indicates
support for RDMA.
The bnxt_ulp_probe() function has been removed and a new
bnxt_rdma_aux_device_add() function has been added.
The bnxt_free_msix_vecs() and bnxt_req_msix_vecs() will now hold
the RTNL lock when they call the bnxt_close_nic()and bnxt_open_nic()
since the device close and open need to be protected under RTNL lock.
The operations between the bnxt_en and bnxt_re will be protected
using the en_ops_lock.
This will be used by the bnxt_re driver in a follow-on patch
to create ROCE interfaces.

Signed-off-by: Ajit Khaparde <ajit.khaparde@broadcom.com>
Reviewed-by: Andy Gospodarek <andrew.gospodarek@broadcom.com>
Reviewed-by: Selvin Xavier <selvin.xavier@broadcom.com>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>

drivers/net/ethernet/broadcom/Kconfig

@@ -213,6 +213,7 @@ config BNXT
 	select NET_DEVLINK
 	select PAGE_POOL
 	select DIMLIB
+	select AUXILIARY_BUS
 	help
 	  This driver supports Broadcom NetXtreme-C/E 10/25/40/50 gigabit
 	  Ethernet cards.  To compile this driver as a module, choose M here:

drivers/net/ethernet/broadcom/bnxt/bnxt.c

@@ -13181,6 +13181,8 @@ static void bnxt_remove_one(struct pci_dev *pdev)
 	if (BNXT_PF(bp))
 		bnxt_sriov_disable(bp);
 
+	bnxt_rdma_aux_device_uninit(bp);
+
 	bnxt_ptp_clear(bp);
 	pci_disable_pcie_error_reporting(pdev);
 	unregister_netdev(dev);
@@ -13776,11 +13778,13 @@ static int bnxt_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 
 	bnxt_dl_fw_reporters_create(bp);
 
+	bnxt_rdma_aux_device_init(bp);
+
 	bnxt_print_device_info(bp);
 
 	pci_save_state(pdev);
-	return 0;
 
+	return 0;
 init_err_cleanup:
 	bnxt_dl_unregister(bp);
 init_err_dl:
@@ -13824,7 +13828,6 @@ static void bnxt_shutdown(struct pci_dev *pdev)
 	if (netif_running(dev))
 		dev_close(dev);
 
-	bnxt_ulp_shutdown(bp);
 	bnxt_clear_int_mode(bp);
 	pci_disable_device(pdev);
 

drivers/net/ethernet/broadcom/bnxt/bnxt.h

@@ -24,6 +24,7 @@
 #include <linux/interrupt.h>
 #include <linux/rhashtable.h>
 #include <linux/crash_dump.h>
+#include <linux/auxiliary_bus.h>
 #include <net/devlink.h>
 #include <net/dst_metadata.h>
 #include <net/xdp.h>
@@ -1631,6 +1632,12 @@ struct bnxt_fw_health {
 #define BNXT_FW_IF_RETRY		10
 #define BNXT_FW_SLOT_RESET_RETRY	4
 
+struct bnxt_aux_priv {
+	struct auxiliary_device aux_dev;
+	struct bnxt_en_dev *edev;
+	int id;
+};
+
 enum board_idx {
 	BCM57301,
 	BCM57302,
@@ -1852,6 +1859,7 @@ struct bnxt {
 #define BNXT_CHIP_P4_PLUS(bp)			\
 	(BNXT_CHIP_P4(bp) || BNXT_CHIP_P5(bp))
 
+	struct bnxt_aux_priv	*aux_priv;
 	struct bnxt_en_dev	*edev;
 
 	struct bnxt_napi	**bnapi;

drivers/net/ethernet/broadcom/bnxt/bnxt_ulp.c

@@ -25,6 +25,8 @@
 #include "bnxt_hwrm.h"
 #include "bnxt_ulp.h"
 
+static DEFINE_IDA(bnxt_aux_dev_ids);
+
 static int bnxt_register_dev(struct bnxt_en_dev *edev, unsigned int ulp_id,
 			     struct bnxt_ulp_ops *ulp_ops, void *handle)
 {
@@ -32,7 +34,6 @@ static int bnxt_register_dev(struct bnxt_en_dev *edev, unsigned int ulp_id,
 	struct bnxt *bp = netdev_priv(dev);
 	struct bnxt_ulp *ulp;
 
-	ASSERT_RTNL();
 	if (ulp_id >= BNXT_MAX_ULP)
 		return -EINVAL;
 
@@ -69,10 +70,11 @@ static int bnxt_unregister_dev(struct bnxt_en_dev *edev, unsigned int ulp_id)
 	struct bnxt_ulp *ulp;
 	int i = 0;
 
-	ASSERT_RTNL();
 	if (ulp_id >= BNXT_MAX_ULP)
 		return -EINVAL;
 
+	edev->flags |= BNXT_EN_FLAG_ULP_STOPPED;
+
 	ulp = &edev->ulp_tbl[ulp_id];
 	if (!rcu_access_pointer(ulp->ulp_ops)) {
 		netdev_err(bp->dev, "ulp id %d not registered\n", ulp_id);
@@ -126,7 +128,6 @@ static int bnxt_req_msix_vecs(struct bnxt_en_dev *edev, unsigned int ulp_id,
 	int total_vecs;
 	int rc = 0;
 
-	ASSERT_RTNL();
 	if (ulp_id != BNXT_ROCE_ULP)
 		return -EINVAL;
 
@@ -153,6 +154,7 @@ static int bnxt_req_msix_vecs(struct bnxt_en_dev *edev, unsigned int ulp_id,
 	edev->ulp_tbl[ulp_id].msix_requested = avail_msix;
 	hw_resc = &bp->hw_resc;
 	total_vecs = idx + avail_msix;
+	rtnl_lock();
 	if (bp->total_irqs < total_vecs ||
 	    (BNXT_NEW_RM(bp) && hw_resc->resv_irqs < total_vecs)) {
 		if (netif_running(dev)) {
@@ -162,6 +164,7 @@ static int bnxt_req_msix_vecs(struct bnxt_en_dev *edev, unsigned int ulp_id,
 			rc = bnxt_reserve_rings(bp, true);
 		}
 	}
+	rtnl_unlock();
 	if (rc) {
 		edev->ulp_tbl[ulp_id].msix_requested = 0;
 		return -EAGAIN;
@@ -184,7 +187,6 @@ static int bnxt_free_msix_vecs(struct bnxt_en_dev *edev, unsigned int ulp_id)
 	struct net_device *dev = edev->net;
 	struct bnxt *bp = netdev_priv(dev);
 
-	ASSERT_RTNL();
 	if (ulp_id != BNXT_ROCE_ULP)
 		return -EINVAL;
 
@@ -193,10 +195,13 @@ static int bnxt_free_msix_vecs(struct bnxt_en_dev *edev, unsigned int ulp_id)
 
 	edev->ulp_tbl[ulp_id].msix_requested = 0;
 	edev->flags &= ~BNXT_EN_FLAG_MSIX_REQUESTED;
+	rtnl_lock();
 	if (netif_running(dev) && !(edev->flags & BNXT_EN_FLAG_ULP_STOPPED)) {
 		bnxt_close_nic(bp, true, false);
 		bnxt_open_nic(bp, true, false);
 	}
+	rtnl_unlock();
+
 	return 0;
 }
 
@@ -347,25 +352,6 @@ void bnxt_ulp_sriov_cfg(struct bnxt *bp, int num_vfs)
 	}
 }
 
-void bnxt_ulp_shutdown(struct bnxt *bp)
-{
-	struct bnxt_en_dev *edev = bp->edev;
-	struct bnxt_ulp_ops *ops;
-	int i;
-
-	if (!edev)
-		return;
-
-	for (i = 0; i < BNXT_MAX_ULP; i++) {
-		struct bnxt_ulp *ulp = &edev->ulp_tbl[i];
-
-		ops = rtnl_dereference(ulp->ulp_ops);
-		if (!ops || !ops->ulp_shutdown)
-			continue;
-		ops->ulp_shutdown(ulp->handle);
-	}
-}
-
 void bnxt_ulp_irq_stop(struct bnxt *bp)
 {
 	struct bnxt_en_dev *edev = bp->edev;
@@ -475,6 +461,108 @@ static const struct bnxt_en_ops bnxt_en_ops_tbl = {
 	.bnxt_register_fw_async_events	= bnxt_register_async_events,
 };
 
+void bnxt_rdma_aux_device_uninit(struct bnxt *bp)
+{
+	struct bnxt_aux_priv *aux_priv;
+	struct auxiliary_device *adev;
+
+	/* Skip if no auxiliary device init was done. */
+	if (!(bp->flags & BNXT_FLAG_ROCE_CAP))
+		return;
+
+	aux_priv = bp->aux_priv;
+	adev = &aux_priv->aux_dev;
+	auxiliary_device_delete(adev);
+	auxiliary_device_uninit(adev);
+}
+
+static void bnxt_aux_dev_release(struct device *dev)
+{
+	struct bnxt_aux_priv *aux_priv =
+		container_of(dev, struct bnxt_aux_priv, aux_dev.dev);
+
+	ida_free(&bnxt_aux_dev_ids, aux_priv->id);
+	kfree(aux_priv->edev);
+	kfree(aux_priv);
+}
+
+static void bnxt_set_edev_info(struct bnxt_en_dev *edev, struct bnxt *bp)
+{
+	edev->en_ops = &bnxt_en_ops_tbl;
+	edev->net = bp->dev;
+	edev->pdev = bp->pdev;
+	edev->l2_db_size = bp->db_size;
+	edev->l2_db_size_nc = bp->db_size;
+
+	if (bp->flags & BNXT_FLAG_ROCEV1_CAP)
+		edev->flags |= BNXT_EN_FLAG_ROCEV1_CAP;
+	if (bp->flags & BNXT_FLAG_ROCEV2_CAP)
+		edev->flags |= BNXT_EN_FLAG_ROCEV2_CAP;
+}
+
+void bnxt_rdma_aux_device_init(struct bnxt *bp)
+{
+	struct auxiliary_device *aux_dev;
+	struct bnxt_aux_priv *aux_priv;
+	struct bnxt_en_dev *edev;
+	int rc;
+
+	if (!(bp->flags & BNXT_FLAG_ROCE_CAP))
+		return;
+
+	bp->aux_priv = kzalloc(sizeof(*bp->aux_priv), GFP_KERNEL);
+	if (!bp->aux_priv)
+		goto exit;
+
+	bp->aux_priv->id = ida_alloc(&bnxt_aux_dev_ids, GFP_KERNEL);
+	if (bp->aux_priv->id < 0) {
+		netdev_warn(bp->dev,
+			    "ida alloc failed for ROCE auxiliary device\n");
+		kfree(bp->aux_priv);
+		goto exit;
+	}
+
+	aux_priv = bp->aux_priv;
+	aux_dev = &aux_priv->aux_dev;
+	aux_dev->id = aux_priv->id;
+	aux_dev->name = "rdma";
+	aux_dev->dev.parent = &bp->pdev->dev;
+	aux_dev->dev.release = bnxt_aux_dev_release;
+
+	rc = auxiliary_device_init(aux_dev);
+	if (rc) {
+		ida_free(&bnxt_aux_dev_ids, bp->aux_priv->id);
+		kfree(bp->aux_priv);
+		goto exit;
+	}
+
+	/* From this point, all cleanup will happen via the .release callback &
+	 * any error unwinding will need to include a call to
+	 * auxiliary_device_uninit.
+	 */
+	edev = kzalloc(sizeof(*edev), GFP_KERNEL);
+	if (!edev)
+		goto aux_dev_uninit;
+
+	aux_priv->edev = edev;
+	bp->edev = edev;
+	bnxt_set_edev_info(edev, bp);
+
+	rc = auxiliary_device_add(aux_dev);
+	if (rc) {
+		netdev_warn(bp->dev,
+			    "Failed to add auxiliary device for ROCE\n");
+		goto aux_dev_uninit;
+	}
+
+	return;
+
+aux_dev_uninit:
+	auxiliary_device_uninit(aux_dev);
+exit:
+	bp->flags &= ~BNXT_FLAG_ROCE_CAP;
+}
+
 struct bnxt_en_dev *bnxt_ulp_probe(struct net_device *dev)
 {
 	struct bnxt *bp = netdev_priv(dev);

drivers/net/ethernet/broadcom/bnxt/bnxt_ulp.h

@@ -102,10 +102,11 @@ int bnxt_get_ulp_stat_ctxs(struct bnxt *bp);
 void bnxt_ulp_stop(struct bnxt *bp);
 void bnxt_ulp_start(struct bnxt *bp, int err);
 void bnxt_ulp_sriov_cfg(struct bnxt *bp, int num_vfs);
-void bnxt_ulp_shutdown(struct bnxt *bp);
 void bnxt_ulp_irq_stop(struct bnxt *bp);
 void bnxt_ulp_irq_restart(struct bnxt *bp, int err);
 void bnxt_ulp_async_events(struct bnxt *bp, struct hwrm_async_event_cmpl *cmpl);
+void bnxt_rdma_aux_device_uninit(struct bnxt *bp);
+void bnxt_rdma_aux_device_init(struct bnxt *bp);
 struct bnxt_en_dev *bnxt_ulp_probe(struct net_device *dev);
 
 #endif