sfc: Associate primary and secondary functions of controller

The primary function of an EF10 controller will share its clock
device with other functions in the same domain (which we call
secondary functions).  To this end, we need to associate functions
on the same controller.

We do not control probe order, so allow primary and secondary
functions to appear in any order.  Maintain global lists of all
primary functions and of unassociated secondary functions,
and a list of secondary functions on each primary function.

Use the VPD serial number to tell whether functions are part of the
same controller.  VPD will not be readable by virtual functions, so
this may need to be revisited later.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

drivers/net/ethernet/sfc/efx.c

@@ -1117,6 +1117,77 @@ static void efx_remove_port(struct efx_nic *efx)
  *
  **************************************************************************/
 
+static LIST_HEAD(efx_primary_list);
+static LIST_HEAD(efx_unassociated_list);
+
+static bool efx_same_controller(struct efx_nic *left, struct efx_nic *right)
+{
+	return left->type == right->type &&
+		left->vpd_sn && right->vpd_sn &&
+		!strcmp(left->vpd_sn, right->vpd_sn);
+}
+
+static void efx_associate(struct efx_nic *efx)
+{
+	struct efx_nic *other, *next;
+
+	if (efx->primary == efx) {
+		/* Adding primary function; look for secondaries */
+
+		netif_dbg(efx, probe, efx->net_dev, "adding to primary list\n");
+		list_add_tail(&efx->node, &efx_primary_list);
+
+		list_for_each_entry_safe(other, next, &efx_unassociated_list,
+					 node) {
+			if (efx_same_controller(efx, other)) {
+				list_del(&other->node);
+				netif_dbg(other, probe, other->net_dev,
+					  "moving to secondary list of %s %s\n",
+					  pci_name(efx->pci_dev),
+					  efx->net_dev->name);
+				list_add_tail(&other->node,
+					      &efx->secondary_list);
+				other->primary = efx;
+			}
+		}
+	} else {
+		/* Adding secondary function; look for primary */
+
+		list_for_each_entry(other, &efx_primary_list, node) {
+			if (efx_same_controller(efx, other)) {
+				netif_dbg(efx, probe, efx->net_dev,
+					  "adding to secondary list of %s %s\n",
+					  pci_name(other->pci_dev),
+					  other->net_dev->name);
+				list_add_tail(&efx->node,
+					      &other->secondary_list);
+				efx->primary = other;
+				return;
+			}
+		}
+
+		netif_dbg(efx, probe, efx->net_dev,
+			  "adding to unassociated list\n");
+		list_add_tail(&efx->node, &efx_unassociated_list);
+	}
+}
+
+static void efx_dissociate(struct efx_nic *efx)
+{
+	struct efx_nic *other, *next;
+
+	list_del(&efx->node);
+	efx->primary = NULL;
+
+	list_for_each_entry_safe(other, next, &efx->secondary_list, node) {
+		list_del(&other->node);
+		netif_dbg(other, probe, other->net_dev,
+			  "moving to unassociated list\n");
+		list_add_tail(&other->node, &efx_unassociated_list);
+		other->primary = NULL;
+	}
+}
+
 /* This configures the PCI device to enable I/O and DMA. */
 static int efx_init_io(struct efx_nic *efx)
 {
@@ -2214,6 +2285,8 @@ static int efx_register_netdev(struct efx_nic *efx)
 			efx_init_tx_queue_core_txq(tx_queue);
 	}
 
+	efx_associate(efx);
+
 	rtnl_unlock();
 
 	rc = device_create_file(&efx->pci_dev->dev, &dev_attr_phy_type);
@@ -2227,6 +2300,7 @@ static int efx_register_netdev(struct efx_nic *efx)
 
 fail_registered:
 	rtnl_lock();
+	efx_dissociate(efx);
 	unregister_netdevice(net_dev);
 fail_locked:
 	efx->state = STATE_UNINIT;
@@ -2568,6 +2642,8 @@ static int efx_init_struct(struct efx_nic *efx,
 	int i;
 
 	/* Initialise common structures */
+	INIT_LIST_HEAD(&efx->node);
+	INIT_LIST_HEAD(&efx->secondary_list);
 	spin_lock_init(&efx->biu_lock);
 #ifdef CONFIG_SFC_MTD
 	INIT_LIST_HEAD(&efx->mtd_list);
@@ -2674,6 +2750,7 @@ static void efx_pci_remove(struct pci_dev *pci_dev)
 
 	/* Mark the NIC as fini, then stop the interface */
 	rtnl_lock();
+	efx_dissociate(efx);
 	dev_close(efx->net_dev);
 	efx_disable_interrupts(efx);
 	rtnl_unlock();

drivers/net/ethernet/sfc/falcon.c

@@ -2247,6 +2247,8 @@ static int falcon_probe_nic(struct efx_nic *efx)
 	struct falcon_board *board;
 	int rc;
 
+	efx->primary = efx; /* only one usable function per controller */
+
 	/* Allocate storage for hardware specific data */
 	nic_data = kzalloc(sizeof(*nic_data), GFP_KERNEL);
 	if (!nic_data)

drivers/net/ethernet/sfc/mcdi.c

@@ -102,6 +102,10 @@ int efx_mcdi_init(struct efx_nic *efx)
 		netif_err(efx, probe, efx->net_dev,
 			  "Host already registered with MCPU\n");
 
+	if (efx->mcdi->fn_flags &
+	    (1 << MC_CMD_DRV_ATTACH_EXT_OUT_FLAG_PRIMARY))
+		efx->primary = efx;
+
 	return 0;
 }
 

drivers/net/ethernet/sfc/net_driver.h

@@ -657,6 +657,13 @@ struct vfdi_status;
  * struct efx_nic - an Efx NIC
  * @name: Device name (net device name or bus id before net device registered)
  * @pci_dev: The PCI device
+ * @node: List node for maintaning primary/secondary function lists
+ * @primary: &struct efx_nic instance for the primary function of this
+ *	controller.  May be the same structure, and may be %NULL if no
+ *	primary function is bound.  Serialised by rtnl_lock.
+ * @secondary_list: List of &struct efx_nic instances for the secondary PCI
+ *	functions of the controller, if this is for the primary function.
+ *	Serialised by rtnl_lock.
  * @type: Controller type attributes
  * @legacy_irq: IRQ number
  * @workqueue: Workqueue for port reconfigures and the HW monitor.
@@ -786,6 +793,9 @@ struct efx_nic {
 	/* The following fields should be written very rarely */
 
 	char name[IFNAMSIZ];
+	struct list_head node;
+	struct efx_nic *primary;
+	struct list_head secondary_list;
 	struct pci_dev *pci_dev;
 	unsigned int port_num;
 	const struct efx_nic_type *type;