1 // SPDX-License-Identifier: GPL-2.0-only
2 // SPDX-FileCopyrightText: Copyright Red Hat
3
4 #include <linux/cleanup.h>
5 #include <linux/mutex.h>
6 #include <linux/pci.h>
7 #include <linux/slab.h>
8 #include <linux/spinlock.h>
9 #include <linux/xarray.h>
10 #include "ice_adapter.h"
11 #include "ice.h"
12
13 static DEFINE_XARRAY(ice_adapters);
14 static DEFINE_MUTEX(ice_adapters_mutex);
15
ice_adapter_index(u64 dsn)16 static unsigned long ice_adapter_index(u64 dsn)
17 {
18 #if BITS_PER_LONG == 64
19 return dsn;
20 #else
21 return (u32)dsn ^ (u32)(dsn >> 32);
22 #endif
23 }
24
ice_adapter_new(u64 dsn)25 static struct ice_adapter *ice_adapter_new(u64 dsn)
26 {
27 struct ice_adapter *adapter;
28
29 adapter = kzalloc(sizeof(*adapter), GFP_KERNEL);
30 if (!adapter)
31 return NULL;
32
33 adapter->device_serial_number = dsn;
34 spin_lock_init(&adapter->ptp_gltsyn_time_lock);
35 refcount_set(&adapter->refcount, 1);
36
37 mutex_init(&adapter->ports.lock);
38 INIT_LIST_HEAD(&adapter->ports.ports);
39
40 return adapter;
41 }
42
ice_adapter_free(struct ice_adapter * adapter)43 static void ice_adapter_free(struct ice_adapter *adapter)
44 {
45 WARN_ON(!list_empty(&adapter->ports.ports));
46 mutex_destroy(&adapter->ports.lock);
47
48 kfree(adapter);
49 }
50
51 /**
52 * ice_adapter_get - Get a shared ice_adapter structure.
53 * @pdev: Pointer to the pci_dev whose driver is getting the ice_adapter.
54 *
55 * Gets a pointer to a shared ice_adapter structure. Physical functions (PFs)
56 * of the same multi-function PCI device share one ice_adapter structure.
57 * The ice_adapter is reference-counted. The PF driver must use ice_adapter_put
58 * to release its reference.
59 *
60 * Context: Process, may sleep.
61 * Return: Pointer to ice_adapter on success.
62 * ERR_PTR() on error. -ENOMEM is the only possible error.
63 */
ice_adapter_get(struct pci_dev * pdev)64 struct ice_adapter *ice_adapter_get(struct pci_dev *pdev)
65 {
66 u64 dsn = pci_get_dsn(pdev);
67 struct ice_adapter *adapter;
68 unsigned long index;
69 int err;
70
71 index = ice_adapter_index(dsn);
72 scoped_guard(mutex, &ice_adapters_mutex) {
73 err = xa_insert(&ice_adapters, index, NULL, GFP_KERNEL);
74 if (err == -EBUSY) {
75 adapter = xa_load(&ice_adapters, index);
76 refcount_inc(&adapter->refcount);
77 WARN_ON_ONCE(adapter->device_serial_number != dsn);
78 return adapter;
79 }
80 if (err)
81 return ERR_PTR(err);
82
83 adapter = ice_adapter_new(dsn);
84 if (!adapter)
85 return ERR_PTR(-ENOMEM);
86 xa_store(&ice_adapters, index, adapter, GFP_KERNEL);
87 }
88 return adapter;
89 }
90
91 /**
92 * ice_adapter_put - Release a reference to the shared ice_adapter structure.
93 * @pdev: Pointer to the pci_dev whose driver is releasing the ice_adapter.
94 *
95 * Releases the reference to ice_adapter previously obtained with
96 * ice_adapter_get.
97 *
98 * Context: Process, may sleep.
99 */
ice_adapter_put(struct pci_dev * pdev)100 void ice_adapter_put(struct pci_dev *pdev)
101 {
102 u64 dsn = pci_get_dsn(pdev);
103 struct ice_adapter *adapter;
104 unsigned long index;
105
106 index = ice_adapter_index(dsn);
107 scoped_guard(mutex, &ice_adapters_mutex) {
108 adapter = xa_load(&ice_adapters, index);
109 if (WARN_ON(!adapter))
110 return;
111 if (!refcount_dec_and_test(&adapter->refcount))
112 return;
113
114 WARN_ON(xa_erase(&ice_adapters, index) != adapter);
115 }
116 ice_adapter_free(adapter);
117 }
118