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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Intel MIC Platform Software Stack (MPSS)
4 *
5 * Copyright(c) 2014 Intel Corporation.
6 *
7 * Intel SCIF driver.
8 */
9#include <linux/idr.h>
10
11#include "scif_main.h"
12
13#define SCIF_PORT_COUNT 0x10000 /* Ports available */
14
15struct idr scif_ports;
16
17/*
18 * struct scif_port - SCIF port information
19 *
20 * @ref_cnt - Reference count since there can be multiple endpoints
21 * created via scif_accept(..) simultaneously using a port.
22 */
23struct scif_port {
24 int ref_cnt;
25};
26
27/**
28 * __scif_get_port - Reserve a specified port # for SCIF and add it
29 * to the global list.
30 * @port : port # to be reserved.
31 *
32 * @return : Allocated SCIF port #, or -ENOSPC if port unavailable.
33 * On memory allocation failure, returns -ENOMEM.
34 */
35static int __scif_get_port(int start, int end)
36{
37 int id;
38 struct scif_port *port = kzalloc(sizeof(*port), GFP_ATOMIC);
39
40 if (!port)
41 return -ENOMEM;
42 spin_lock(&scif_info.port_lock);
43 id = idr_alloc(&scif_ports, port, start, end, GFP_ATOMIC);
44 if (id >= 0)
45 port->ref_cnt++;
46 spin_unlock(&scif_info.port_lock);
47 return id;
48}
49
50/**
51 * scif_rsrv_port - Reserve a specified port # for SCIF.
52 * @port : port # to be reserved.
53 *
54 * @return : Allocated SCIF port #, or -ENOSPC if port unavailable.
55 * On memory allocation failure, returns -ENOMEM.
56 */
57int scif_rsrv_port(u16 port)
58{
59 return __scif_get_port(port, port + 1);
60}
61
62/**
63 * scif_get_new_port - Get and reserve any port # for SCIF in the range
64 * SCIF_PORT_RSVD + 1 to SCIF_PORT_COUNT - 1.
65 *
66 * @return : Allocated SCIF port #, or -ENOSPC if no ports available.
67 * On memory allocation failure, returns -ENOMEM.
68 */
69int scif_get_new_port(void)
70{
71 return __scif_get_port(SCIF_PORT_RSVD + 1, SCIF_PORT_COUNT);
72}
73
74/**
75 * scif_get_port - Increment the reference count for a SCIF port
76 * @id : SCIF port
77 *
78 * @return : None
79 */
80void scif_get_port(u16 id)
81{
82 struct scif_port *port;
83
84 if (!id)
85 return;
86 spin_lock(&scif_info.port_lock);
87 port = idr_find(&scif_ports, id);
88 if (port)
89 port->ref_cnt++;
90 spin_unlock(&scif_info.port_lock);
91}
92
93/**
94 * scif_put_port - Release a reserved SCIF port
95 * @id : SCIF port to be released.
96 *
97 * @return : None
98 */
99void scif_put_port(u16 id)
100{
101 struct scif_port *port;
102
103 if (!id)
104 return;
105 spin_lock(&scif_info.port_lock);
106 port = idr_find(&scif_ports, id);
107 if (port) {
108 port->ref_cnt--;
109 if (!port->ref_cnt) {
110 idr_remove(&scif_ports, id);
111 kfree(port);
112 }
113 }
114 spin_unlock(&scif_info.port_lock);
115}