1 // SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
2 /* Copyright (c) 2020 Marvell International Ltd. All rights reserved */
3 
4 #include <linux/kernel.h>
5 #include <linux/list.h>
6 
7 #include "prestera.h"
8 #include "prestera_hw.h"
9 #include "prestera_acl.h"
10 #include "prestera_flow.h"
11 #include "prestera_span.h"
12 
13 struct prestera_span_entry {
14 	struct list_head list;
15 	struct prestera_port *port;
16 	refcount_t ref_count;
17 	u8 id;
18 };
19 
20 struct prestera_span {
21 	struct prestera_switch *sw;
22 	struct list_head entries;
23 };
24 
25 static struct prestera_span_entry *
26 prestera_span_entry_create(struct prestera_port *port, u8 span_id)
27 {
28 	struct prestera_span_entry *entry;
29 
30 	entry = kzalloc(sizeof(*entry), GFP_KERNEL);
31 	if (!entry)
32 		return ERR_PTR(-ENOMEM);
33 
34 	refcount_set(&entry->ref_count, 1);
35 	entry->port = port;
36 	entry->id = span_id;
37 	list_add_tail(&entry->list, &port->sw->span->entries);
38 
39 	return entry;
40 }
41 
42 static void prestera_span_entry_del(struct prestera_span_entry *entry)
43 {
44 	list_del(&entry->list);
45 	kfree(entry);
46 }
47 
48 static struct prestera_span_entry *
49 prestera_span_entry_find_by_id(struct prestera_span *span, u8 span_id)
50 {
51 	struct prestera_span_entry *entry;
52 
53 	list_for_each_entry(entry, &span->entries, list) {
54 		if (entry->id == span_id)
55 			return entry;
56 	}
57 
58 	return NULL;
59 }
60 
61 static struct prestera_span_entry *
62 prestera_span_entry_find_by_port(struct prestera_span *span,
63 				 struct prestera_port *port)
64 {
65 	struct prestera_span_entry *entry;
66 
67 	list_for_each_entry(entry, &span->entries, list) {
68 		if (entry->port == port)
69 			return entry;
70 	}
71 
72 	return NULL;
73 }
74 
75 static int prestera_span_get(struct prestera_port *port, u8 *span_id)
76 {
77 	u8 new_span_id;
78 	struct prestera_switch *sw = port->sw;
79 	struct prestera_span_entry *entry;
80 	int err;
81 
82 	entry = prestera_span_entry_find_by_port(sw->span, port);
83 	if (entry) {
84 		refcount_inc(&entry->ref_count);
85 		*span_id = entry->id;
86 		return 0;
87 	}
88 
89 	err = prestera_hw_span_get(port, &new_span_id);
90 	if (err)
91 		return err;
92 
93 	entry = prestera_span_entry_create(port, new_span_id);
94 	if (IS_ERR(entry)) {
95 		prestera_hw_span_release(sw, new_span_id);
96 		return PTR_ERR(entry);
97 	}
98 
99 	*span_id = new_span_id;
100 	return 0;
101 }
102 
103 static int prestera_span_put(struct prestera_switch *sw, u8 span_id)
104 {
105 	struct prestera_span_entry *entry;
106 	int err;
107 
108 	entry = prestera_span_entry_find_by_id(sw->span, span_id);
109 	if (!entry)
110 		return -ENOENT;
111 
112 	if (!refcount_dec_and_test(&entry->ref_count))
113 		return 0;
114 
115 	err = prestera_hw_span_release(sw, span_id);
116 	if (err)
117 		return err;
118 
119 	prestera_span_entry_del(entry);
120 	return 0;
121 }
122 
123 int prestera_span_rule_add(struct prestera_flow_block_binding *binding,
124 			   struct prestera_port *to_port,
125 			   bool ingress)
126 {
127 	struct prestera_switch *sw = binding->port->sw;
128 	u8 span_id;
129 	int err;
130 
131 	if (binding->span_id != PRESTERA_SPAN_INVALID_ID)
132 		/* port already in mirroring */
133 		return -EEXIST;
134 
135 	err = prestera_span_get(to_port, &span_id);
136 	if (err)
137 		return err;
138 
139 	err = prestera_hw_span_bind(binding->port, span_id, ingress);
140 	if (err) {
141 		prestera_span_put(sw, span_id);
142 		return err;
143 	}
144 
145 	binding->span_id = span_id;
146 	return 0;
147 }
148 
149 int prestera_span_rule_del(struct prestera_flow_block_binding *binding,
150 			   bool ingress)
151 {
152 	int err;
153 
154 	if (binding->span_id == PRESTERA_SPAN_INVALID_ID)
155 		return -ENOENT;
156 
157 	err = prestera_hw_span_unbind(binding->port, ingress);
158 	if (err)
159 		return err;
160 
161 	err = prestera_span_put(binding->port->sw, binding->span_id);
162 	if (err)
163 		return err;
164 
165 	binding->span_id = PRESTERA_SPAN_INVALID_ID;
166 	return 0;
167 }
168 
169 int prestera_span_init(struct prestera_switch *sw)
170 {
171 	struct prestera_span *span;
172 
173 	span = kzalloc(sizeof(*span), GFP_KERNEL);
174 	if (!span)
175 		return -ENOMEM;
176 
177 	INIT_LIST_HEAD(&span->entries);
178 
179 	sw->span = span;
180 	span->sw = sw;
181 
182 	return 0;
183 }
184 
185 void prestera_span_fini(struct prestera_switch *sw)
186 {
187 	struct prestera_span *span = sw->span;
188 
189 	WARN_ON(!list_empty(&span->entries));
190 	kfree(span);
191 }
192