xref: /linux/drivers/net/dsa/microchip/ksz9477_tc_flower.c (revision 3652117f854819a148ff0fbe4492587d3520b5e5)
1 // SPDX-License-Identifier: GPL-2.0
2 // Copyright (c) 2023 Pengutronix, Oleksij Rempel <kernel@pengutronix.de>
3 
4 #include "ksz9477.h"
5 #include "ksz9477_reg.h"
6 #include "ksz_common.h"
7 
8 #define ETHER_TYPE_FULL_MASK		cpu_to_be16(~0)
9 #define KSZ9477_MAX_TC			7
10 
11 /**
12  * ksz9477_flower_parse_key_l2 - Parse Layer 2 key from flow rule and configure
13  *                               ACL entries accordingly.
14  * @dev: Pointer to the ksz_device.
15  * @port: Port number.
16  * @extack: Pointer to the netlink_ext_ack.
17  * @rule: Pointer to the flow_rule.
18  * @cookie: The cookie to associate with the entry.
19  * @prio: The priority of the entry.
20  *
21  * This function parses the Layer 2 key from the flow rule and configures
22  * the corresponding ACL entries. It checks for unsupported offloads and
23  * available entries before proceeding with the configuration.
24  *
25  * Returns: 0 on success or a negative error code on failure.
26  */
27 static int ksz9477_flower_parse_key_l2(struct ksz_device *dev, int port,
28 				       struct netlink_ext_ack *extack,
29 				       struct flow_rule *rule,
30 				       unsigned long cookie, u32 prio)
31 {
32 	struct ksz9477_acl_priv *acl = dev->ports[port].acl_priv;
33 	struct flow_match_eth_addrs ematch;
34 	struct ksz9477_acl_entries *acles;
35 	int required_entries;
36 	u8 *src_mac = NULL;
37 	u8 *dst_mac = NULL;
38 	u16 ethtype = 0;
39 
40 	if (flow_rule_match_key(rule, FLOW_DISSECTOR_KEY_BASIC)) {
41 		struct flow_match_basic match;
42 
43 		flow_rule_match_basic(rule, &match);
44 
45 		if (match.key->n_proto) {
46 			if (match.mask->n_proto != ETHER_TYPE_FULL_MASK) {
47 				NL_SET_ERR_MSG_MOD(extack,
48 						   "ethernet type mask must be a full mask");
49 				return -EINVAL;
50 			}
51 
52 			ethtype = be16_to_cpu(match.key->n_proto);
53 		}
54 	}
55 
56 	if (flow_rule_match_key(rule, FLOW_DISSECTOR_KEY_ETH_ADDRS)) {
57 		flow_rule_match_eth_addrs(rule, &ematch);
58 
59 		if (!is_zero_ether_addr(ematch.key->src)) {
60 			if (!is_broadcast_ether_addr(ematch.mask->src))
61 				goto not_full_mask_err;
62 
63 			src_mac = ematch.key->src;
64 		}
65 
66 		if (!is_zero_ether_addr(ematch.key->dst)) {
67 			if (!is_broadcast_ether_addr(ematch.mask->dst))
68 				goto not_full_mask_err;
69 
70 			dst_mac = ematch.key->dst;
71 		}
72 	}
73 
74 	acles = &acl->acles;
75 	/* ACL supports only one MAC per entry */
76 	required_entries = src_mac && dst_mac ? 2 : 1;
77 
78 	/* Check if there are enough available entries */
79 	if (acles->entries_count + required_entries > KSZ9477_ACL_MAX_ENTRIES) {
80 		NL_SET_ERR_MSG_MOD(extack, "ACL entry limit reached");
81 		return -EOPNOTSUPP;
82 	}
83 
84 	ksz9477_acl_match_process_l2(dev, port, ethtype, src_mac, dst_mac,
85 				     cookie, prio);
86 
87 	return 0;
88 
89 not_full_mask_err:
90 	NL_SET_ERR_MSG_MOD(extack, "MAC address mask must be a full mask");
91 	return -EOPNOTSUPP;
92 }
93 
94 /**
95  * ksz9477_flower_parse_key - Parse flow rule keys for a specified port on a
96  *			      ksz_device.
97  * @dev: The ksz_device instance.
98  * @port: The port number to parse the flow rule keys for.
99  * @extack: The netlink extended ACK for reporting errors.
100  * @rule: The flow_rule to parse.
101  * @cookie: The cookie to associate with the entry.
102  * @prio: The priority of the entry.
103  *
104  * This function checks if the used keys in the flow rule are supported by
105  * the device and parses the L2 keys if they match. If unsupported keys are
106  * used, an error message is set in the extended ACK.
107  *
108  * Returns: 0 on success or a negative error code on failure.
109  */
110 static int ksz9477_flower_parse_key(struct ksz_device *dev, int port,
111 				    struct netlink_ext_ack *extack,
112 				    struct flow_rule *rule,
113 				    unsigned long cookie, u32 prio)
114 {
115 	struct flow_dissector *dissector = rule->match.dissector;
116 	int ret;
117 
118 	if (dissector->used_keys &
119 	    ~(BIT_ULL(FLOW_DISSECTOR_KEY_BASIC) |
120 	      BIT_ULL(FLOW_DISSECTOR_KEY_ETH_ADDRS) |
121 	      BIT_ULL(FLOW_DISSECTOR_KEY_CONTROL))) {
122 		NL_SET_ERR_MSG_MOD(extack,
123 				   "Unsupported keys used");
124 		return -EOPNOTSUPP;
125 	}
126 
127 	if (flow_rule_match_key(rule, FLOW_DISSECTOR_KEY_BASIC) ||
128 	    flow_rule_match_key(rule, FLOW_DISSECTOR_KEY_ETH_ADDRS)) {
129 		ret = ksz9477_flower_parse_key_l2(dev, port, extack, rule,
130 						  cookie, prio);
131 		if (ret)
132 			return ret;
133 	}
134 
135 	return 0;
136 }
137 
138 /**
139  * ksz9477_flower_parse_action - Parse flow rule actions for a specified port
140  *				 on a ksz_device.
141  * @dev: The ksz_device instance.
142  * @port: The port number to parse the flow rule actions for.
143  * @extack: The netlink extended ACK for reporting errors.
144  * @cls: The flow_cls_offload instance containing the flow rule.
145  * @entry_idx: The index of the ACL entry to store the action.
146  *
147  * This function checks if the actions in the flow rule are supported by
148  * the device. Currently, only actions that change priorities are supported.
149  * If unsupported actions are encountered, an error message is set in the
150  * extended ACK.
151  *
152  * Returns: 0 on success or a negative error code on failure.
153  */
154 static int ksz9477_flower_parse_action(struct ksz_device *dev, int port,
155 				       struct netlink_ext_ack *extack,
156 				       struct flow_cls_offload *cls,
157 				       int entry_idx)
158 {
159 	struct flow_rule *rule = flow_cls_offload_flow_rule(cls);
160 	struct ksz9477_acl_priv *acl = dev->ports[port].acl_priv;
161 	const struct flow_action_entry *act;
162 	struct ksz9477_acl_entry *entry;
163 	bool prio_force = false;
164 	u8 prio_val = 0;
165 	int i;
166 
167 	if (TC_H_MIN(cls->classid)) {
168 		NL_SET_ERR_MSG_MOD(extack, "hw_tc is not supported. Use: action skbedit prio");
169 		return -EOPNOTSUPP;
170 	}
171 
172 	flow_action_for_each(i, act, &rule->action) {
173 		switch (act->id) {
174 		case FLOW_ACTION_PRIORITY:
175 			if (act->priority > KSZ9477_MAX_TC) {
176 				NL_SET_ERR_MSG_MOD(extack, "Priority value is too high");
177 				return -EOPNOTSUPP;
178 			}
179 			prio_force = true;
180 			prio_val = act->priority;
181 			break;
182 		default:
183 			NL_SET_ERR_MSG_MOD(extack, "action not supported");
184 			return -EOPNOTSUPP;
185 		}
186 	}
187 
188 	/* pick entry to store action */
189 	entry = &acl->acles.entries[entry_idx];
190 
191 	ksz9477_acl_action_rule_cfg(entry->entry, prio_force, prio_val);
192 	ksz9477_acl_processing_rule_set_action(entry->entry, entry_idx);
193 
194 	return 0;
195 }
196 
197 /**
198  * ksz9477_cls_flower_add - Add a flow classification rule for a specified port
199  *			    on a ksz_device.
200  * @ds: The DSA switch instance.
201  * @port: The port number to add the flow classification rule to.
202  * @cls: The flow_cls_offload instance containing the flow rule.
203  * @ingress: A flag indicating if the rule is applied on the ingress path.
204  *
205  * This function adds a flow classification rule for a specified port on a
206  * ksz_device. It checks if the ACL offloading is supported and parses the flow
207  * keys and actions. If the ACL is not supported, it returns an error. If there
208  * are unprocessed entries, it parses the action for the rule.
209  *
210  * Returns: 0 on success or a negative error code on failure.
211  */
212 int ksz9477_cls_flower_add(struct dsa_switch *ds, int port,
213 			   struct flow_cls_offload *cls, bool ingress)
214 {
215 	struct flow_rule *rule = flow_cls_offload_flow_rule(cls);
216 	struct netlink_ext_ack *extack = cls->common.extack;
217 	struct ksz_device *dev = ds->priv;
218 	struct ksz9477_acl_priv *acl;
219 	int action_entry_idx;
220 	int ret;
221 
222 	acl = dev->ports[port].acl_priv;
223 
224 	if (!acl) {
225 		NL_SET_ERR_MSG_MOD(extack, "ACL offloading is not supported");
226 		return -EOPNOTSUPP;
227 	}
228 
229 	/* A complex rule set can take multiple entries. Use first entry
230 	 * to store the action.
231 	 */
232 	action_entry_idx = acl->acles.entries_count;
233 
234 	ret = ksz9477_flower_parse_key(dev, port, extack, rule, cls->cookie,
235 				       cls->common.prio);
236 	if (ret)
237 		return ret;
238 
239 	ret = ksz9477_flower_parse_action(dev, port, extack, cls,
240 					  action_entry_idx);
241 	if (ret)
242 		return ret;
243 
244 	ret = ksz9477_sort_acl_entries(dev, port);
245 	if (ret)
246 		return ret;
247 
248 	return ksz9477_acl_write_list(dev, port);
249 }
250 
251 /**
252  * ksz9477_cls_flower_del - Remove a flow classification rule for a specified
253  *			    port on a ksz_device.
254  * @ds: The DSA switch instance.
255  * @port: The port number to remove the flow classification rule from.
256  * @cls: The flow_cls_offload instance containing the flow rule.
257  * @ingress: A flag indicating if the rule is applied on the ingress path.
258  *
259  * This function removes a flow classification rule for a specified port on a
260  * ksz_device. It checks if the ACL is initialized, and if not, returns an
261  * error. If the ACL is initialized, it removes entries with the specified
262  * cookie and rewrites the ACL list.
263  *
264  * Returns: 0 on success or a negative error code on failure.
265  */
266 int ksz9477_cls_flower_del(struct dsa_switch *ds, int port,
267 			   struct flow_cls_offload *cls, bool ingress)
268 {
269 	unsigned long cookie = cls->cookie;
270 	struct ksz_device *dev = ds->priv;
271 	struct ksz9477_acl_priv *acl;
272 
273 	acl = dev->ports[port].acl_priv;
274 
275 	if (!acl)
276 		return -EOPNOTSUPP;
277 
278 	ksz9477_acl_remove_entries(dev, port, &acl->acles, cookie);
279 
280 	return ksz9477_acl_write_list(dev, port);
281 }
282