1 files changed, 147 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..0a8a48cd4bce
--- /dev/null
+++ b/drivers/net/ethernet/intel/ice/ice_adapter.c
@@ -0,0 +1,147 @@
+// SPDX-License-Identifier: GPL-2.0-only
+// SPDX-FileCopyrightText: Copyright Red Hat
+
+#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);
+
+#define ICE_ADAPTER_FIXED_INDEX	BIT_ULL(63)
+
+#define ICE_ADAPTER_INDEX_E825C	\
+	(ICE_DEV_ID_E825C_BACKPLANE | ICE_ADAPTER_FIXED_INDEX)
+
+static u64 ice_adapter_index(struct pci_dev *pdev)
+{
+	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:
+		/* E825C devices have multiple NACs which are connected to the
+		 * same clock source, and which must share the same
+		 * ice_adapter structure. We can't use the serial number since
+		 * each NAC has its own NVM generated with its own unique
+		 * Device Serial Number. Instead, rely on the embedded nature
+		 * of the E825C devices, and use a fixed index. This relies on
+		 * the fact that all E825C physical functions in a given
+		 * system are part of the same overall device.
+		 */
+		return ICE_ADAPTER_INDEX_E825C;
+	default:
+		return pci_get_dsn(pdev) & ~ICE_ADAPTER_FIXED_INDEX;
+	}
+}
+
+static unsigned long ice_adapter_xa_index(struct pci_dev *pdev)
+{
+	u64 index = ice_adapter_index(pdev);
+
+#if BITS_PER_LONG == 64
+	return index;
+#else
+	return (u32)index ^ (u32)(index >> 32);
+#endif
+}
+
+static struct ice_adapter *ice_adapter_new(struct pci_dev *pdev)
+{
+	struct ice_adapter *adapter;
+
+	adapter = kzalloc(sizeof(*adapter), GFP_KERNEL);
+	if (!adapter)
+		return NULL;
+
+	adapter->index = ice_adapter_index(pdev);
+	spin_lock_init(&adapter->ptp_gltsyn_time_lock);
+	spin_lock_init(&adapter->txq_ctx_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(struct pci_dev *pdev)
+{
+	struct ice_adapter *adapter;
+	unsigned long index;
+	int err;
+
+	index = ice_adapter_xa_index(pdev);
+	scoped_guard(mutex, &ice_adapters_mutex) {
+		adapter = xa_load(&ice_adapters, index);
+		if (adapter) {
+			refcount_inc(&adapter->refcount);
+			WARN_ON_ONCE(adapter->index != ice_adapter_index(pdev));
+			return adapter;
+		}
+		err = xa_reserve(&ice_adapters, index, GFP_KERNEL);
+		if (err)
+			return ERR_PTR(err);
+
+		adapter = ice_adapter_new(pdev);
+		if (!adapter) {
+			xa_release(&ice_adapters, index);
+			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(struct pci_dev *pdev)
+{
+	struct ice_adapter *adapter;
+	unsigned long index;
+
+	index = ice_adapter_xa_index(pdev);
+	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);
+}