1 files changed, 128 insertions, 0 deletions
diff --git a/drivers/net/ethernet/intel/ice/ice_adapter.c b/drivers/net/ethernet/intel/ice/ice_adapter.c
new file mode 100644
index 000000000000..01a08cfd0090
--- /dev/null
+++ b/drivers/net/ethernet/intel/ice/ice_adapter.c
@@ -0,0 +1,128 @@
+// SPDX-License-Identifier: GPL-2.0-only
+// SPDX-FileCopyrightText: Copyright Red Hat
+
+#include <linux/bitfield.h>
+#include <linux/cleanup.h>
+#include <linux/mutex.h>
+#include <linux/pci.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/xarray.h>
+#include "ice_adapter.h"
+#include "ice.h"
+
+static DEFINE_XARRAY(ice_adapters);
+static DEFINE_MUTEX(ice_adapters_mutex);
+
+/* PCI bus number is 8 bits. Slot is 5 bits. Domain can have the rest. */
+#define INDEX_FIELD_DOMAIN GENMASK(BITS_PER_LONG - 1, 13)
+#define INDEX_FIELD_DEV    GENMASK(31, 16)
+#define INDEX_FIELD_BUS    GENMASK(12, 5)
+#define INDEX_FIELD_SLOT   GENMASK(4, 0)
+
+static unsigned long ice_adapter_index(const struct pci_dev *pdev)
+{
+	unsigned int domain = pci_domain_nr(pdev->bus);
+
+	WARN_ON(domain > FIELD_MAX(INDEX_FIELD_DOMAIN));
+
+	switch (pdev->device) {
+	case ICE_DEV_ID_E825C_BACKPLANE:
+	case ICE_DEV_ID_E825C_QSFP:
+	case ICE_DEV_ID_E825C_SFP:
+	case ICE_DEV_ID_E825C_SGMII:
+		return FIELD_PREP(INDEX_FIELD_DEV, pdev->device);
+	default:
+		return FIELD_PREP(INDEX_FIELD_DOMAIN, domain) |
+		       FIELD_PREP(INDEX_FIELD_BUS,    pdev->bus->number) |
+		       FIELD_PREP(INDEX_FIELD_SLOT,   PCI_SLOT(pdev->devfn));
+	}
+}
+
+static struct ice_adapter *ice_adapter_new(void)
+{
+	struct ice_adapter *adapter;
+
+	adapter = kzalloc(sizeof(*adapter), GFP_KERNEL);
+	if (!adapter)
+		return NULL;
+
+	spin_lock_init(&adapter->ptp_gltsyn_time_lock);
+	refcount_set(&adapter->refcount, 1);
+
+	mutex_init(&adapter->ports.lock);
+	INIT_LIST_HEAD(&adapter->ports.ports);
+
+	return adapter;
+}
+
+static void ice_adapter_free(struct ice_adapter *adapter)
+{
+	WARN_ON(!list_empty(&adapter->ports.ports));
+	mutex_destroy(&adapter->ports.lock);
+
+	kfree(adapter);
+}
+
+/**
+ * ice_adapter_get - Get a shared ice_adapter structure.
+ * @pdev: Pointer to the pci_dev whose driver is getting the ice_adapter.
+ *
+ * Gets a pointer to a shared ice_adapter structure. Physical functions (PFs)
+ * of the same multi-function PCI device share one ice_adapter structure.
+ * The ice_adapter is reference-counted. The PF driver must use ice_adapter_put
+ * to release its reference.
+ *
+ * Context: Process, may sleep.
+ * Return:  Pointer to ice_adapter on success.
+ *          ERR_PTR() on error. -ENOMEM is the only possible error.
+ */
+struct ice_adapter *ice_adapter_get(const struct pci_dev *pdev)
+{
+	unsigned long index = ice_adapter_index(pdev);
+	struct ice_adapter *adapter;
+	int err;
+
+	scoped_guard(mutex, &ice_adapters_mutex) {
+		err = xa_insert(&ice_adapters, index, NULL, GFP_KERNEL);
+		if (err == -EBUSY) {
+			adapter = xa_load(&ice_adapters, index);
+			refcount_inc(&adapter->refcount);
+			return adapter;
+		}
+		if (err)
+			return ERR_PTR(err);
+
+		adapter = ice_adapter_new();
+		if (!adapter)
+			return ERR_PTR(-ENOMEM);
+		xa_store(&ice_adapters, index, adapter, GFP_KERNEL);
+	}
+	return adapter;
+}
+
+/**
+ * ice_adapter_put - Release a reference to the shared ice_adapter structure.
+ * @pdev: Pointer to the pci_dev whose driver is releasing the ice_adapter.
+ *
+ * Releases the reference to ice_adapter previously obtained with
+ * ice_adapter_get.
+ *
+ * Context: Process, may sleep.
+ */
+void ice_adapter_put(const struct pci_dev *pdev)
+{
+	unsigned long index = ice_adapter_index(pdev);
+	struct ice_adapter *adapter;
+
+	scoped_guard(mutex, &ice_adapters_mutex) {
+		adapter = xa_load(&ice_adapters, index);
+		if (WARN_ON(!adapter))
+			return;
+		if (!refcount_dec_and_test(&adapter->refcount))
+			return;
+
+		WARN_ON(xa_erase(&ice_adapters, index) != adapter);
+	}
+	ice_adapter_free(adapter);
+}