1// SPDX-License-Identifier: GPL-2.0-only
  2// SPDX-FileCopyrightText: Copyright Red Hat
  3
  4#include <linux/bitfield.h>
  5#include <linux/cleanup.h>
  6#include <linux/mutex.h>
  7#include <linux/pci.h>
  8#include <linux/slab.h>
  9#include <linux/spinlock.h>
 10#include <linux/xarray.h>
 11#include "ice_adapter.h"
 12#include "ice.h"
 13
 14static DEFINE_XARRAY(ice_adapters);
 15static DEFINE_MUTEX(ice_adapters_mutex);
 16
 17/* PCI bus number is 8 bits. Slot is 5 bits. Domain can have the rest. */
 18#define INDEX_FIELD_DOMAIN GENMASK(BITS_PER_LONG - 1, 13)
 19#define INDEX_FIELD_DEV    GENMASK(31, 16)
 20#define INDEX_FIELD_BUS    GENMASK(12, 5)
 21#define INDEX_FIELD_SLOT   GENMASK(4, 0)
 22
 23static unsigned long ice_adapter_index(const struct pci_dev *pdev)
 24{
 25	unsigned int domain = pci_domain_nr(pdev->bus);
 26
 27	WARN_ON(domain > FIELD_MAX(INDEX_FIELD_DOMAIN));
 28
 29	switch (pdev->device) {
 30	case ICE_DEV_ID_E825C_BACKPLANE:
 31	case ICE_DEV_ID_E825C_QSFP:
 32	case ICE_DEV_ID_E825C_SFP:
 33	case ICE_DEV_ID_E825C_SGMII:
 34		return FIELD_PREP(INDEX_FIELD_DEV, pdev->device);
 35	default:
 36		return FIELD_PREP(INDEX_FIELD_DOMAIN, domain) |
 37		       FIELD_PREP(INDEX_FIELD_BUS,    pdev->bus->number) |
 38		       FIELD_PREP(INDEX_FIELD_SLOT,   PCI_SLOT(pdev->devfn));
 39	}
 40}
 41
 42static struct ice_adapter *ice_adapter_new(void)
 43{
 44	struct ice_adapter *adapter;
 45
 46	adapter = kzalloc(sizeof(*adapter), GFP_KERNEL);
 47	if (!adapter)
 48		return NULL;
 49
 50	spin_lock_init(&adapter->ptp_gltsyn_time_lock);
 51	refcount_set(&adapter->refcount, 1);
 52
 53	mutex_init(&adapter->ports.lock);
 54	INIT_LIST_HEAD(&adapter->ports.ports);
 55
 56	return adapter;
 57}
 58
 59static void ice_adapter_free(struct ice_adapter *adapter)
 60{
 61	WARN_ON(!list_empty(&adapter->ports.ports));
 62	mutex_destroy(&adapter->ports.lock);
 63
 64	kfree(adapter);
 65}
 66
 67/**
 68 * ice_adapter_get - Get a shared ice_adapter structure.
 69 * @pdev: Pointer to the pci_dev whose driver is getting the ice_adapter.
 70 *
 71 * Gets a pointer to a shared ice_adapter structure. Physical functions (PFs)
 72 * of the same multi-function PCI device share one ice_adapter structure.
 73 * The ice_adapter is reference-counted. The PF driver must use ice_adapter_put
 74 * to release its reference.
 75 *
 76 * Context: Process, may sleep.
 77 * Return:  Pointer to ice_adapter on success.
 78 *          ERR_PTR() on error. -ENOMEM is the only possible error.
 79 */
 80struct ice_adapter *ice_adapter_get(const struct pci_dev *pdev)
 81{
 82	unsigned long index = ice_adapter_index(pdev);
 83	struct ice_adapter *adapter;
 84	int err;
 85
 86	scoped_guard(mutex, &ice_adapters_mutex) {
 87		err = xa_insert(&ice_adapters, index, NULL, GFP_KERNEL);
 88		if (err == -EBUSY) {
 89			adapter = xa_load(&ice_adapters, index);
 90			refcount_inc(&adapter->refcount);
 91			return adapter;
 92		}
 93		if (err)
 94			return ERR_PTR(err);
 95
 96		adapter = ice_adapter_new();
 97		if (!adapter)
 98			return ERR_PTR(-ENOMEM);
 99		xa_store(&ice_adapters, index, adapter, GFP_KERNEL);
100	}
101	return adapter;
102}
103
104/**
105 * ice_adapter_put - Release a reference to the shared ice_adapter structure.
106 * @pdev: Pointer to the pci_dev whose driver is releasing the ice_adapter.
107 *
108 * Releases the reference to ice_adapter previously obtained with
109 * ice_adapter_get.
110 *
111 * Context: Process, may sleep.
112 */
113void ice_adapter_put(const struct pci_dev *pdev)
114{
115	unsigned long index = ice_adapter_index(pdev);
116	struct ice_adapter *adapter;
117
118	scoped_guard(mutex, &ice_adapters_mutex) {
119		adapter = xa_load(&ice_adapters, index);
120		if (WARN_ON(!adapter))
121			return;
122		if (!refcount_dec_and_test(&adapter->refcount))
123			return;
124
125		WARN_ON(xa_erase(&ice_adapters, index) != adapter);
126	}
127	ice_adapter_free(adapter);
128}