xref: /dpdk/drivers/net/sfc/sfc_switch.c (revision 3bb3ebb51b789d4ecb417cbdb1dce5c7211f6f18)
1 /* SPDX-License-Identifier: BSD-3-Clause
2  *
3  * Copyright(c) 2019-2021 Xilinx, Inc.
4  * Copyright(c) 2019 Solarflare Communications Inc.
5  *
6  * This software was jointly developed between OKTET Labs (under contract
7  * for Solarflare) and Solarflare Communications, Inc.
8  */
9 
10 #include <stdbool.h>
11 
12 #include <rte_common.h>
13 #include <rte_spinlock.h>
14 
15 #include "efx.h"
16 
17 #include "sfc.h"
18 #include "sfc_log.h"
19 #include "sfc_switch.h"
20 
21 /**
22  * Switch port registry entry.
23  *
24  * Drivers aware of RTE switch domains also have to maintain RTE switch
25  * port IDs for RTE ethdev instances they operate. These IDs are supposed
26  * to stand for physical interconnect entities, in example, PCIe functions.
27  *
28  * In terms of MAE, a physical interconnect entity can be referred to using
29  * an MPORT selector, that is, a 32-bit value. RTE switch port IDs, in turn,
30  * are 16-bit values, so indirect mapping has to be maintained:
31  *
32  * +--------------------+          +---------------------------------------+
33  * | RTE switch port ID |  ------  |         MAE switch port entry         |
34  * +--------------------+          |         ---------------------         |
35  *                                 |                                       |
36  *                                 | Entity (PCIe function) MPORT selector |
37  *                                 |                   +                   |
38  *                                 |  Port type (independent/representor)  |
39  *                                 +---------------------------------------+
40  *
41  * This mapping comprises a port type to ensure that RTE switch port ID
42  * of a represented entity and that of its representor are different in
43  * the case when the entity gets plugged into DPDK and not into a guest.
44  *
45  * Entry data also comprises RTE ethdev's own MPORT. This value
46  * coincides with the entity MPORT in the case of independent ports.
47  * In the case of representors, this ID is not a selector and refers
48  * to an allocatable object (that is, it's likely to change on RTE
49  * ethdev replug). Flow API backend must use this value rather
50  * than entity_mport to support flow rule action PORT_ID.
51  */
52 struct sfc_mae_switch_port {
53 	TAILQ_ENTRY(sfc_mae_switch_port)	switch_domain_ports;
54 
55 	/** RTE ethdev MPORT */
56 	efx_mport_sel_t				ethdev_mport;
57 	/** RTE ethdev port ID */
58 	uint16_t				ethdev_port_id;
59 
60 	/** Entity (PCIe function) MPORT selector */
61 	efx_mport_sel_t				entity_mport;
62 	/** Port type (independent/representor) */
63 	enum sfc_mae_switch_port_type		type;
64 	/** RTE switch port ID */
65 	uint16_t				id;
66 };
67 
68 TAILQ_HEAD(sfc_mae_switch_ports, sfc_mae_switch_port);
69 
70 /**
71  * Switch domain registry entry.
72  *
73  * Even if an RTE ethdev instance gets unplugged, the corresponding
74  * entry in the switch port registry will not be removed because the
75  * entity (PCIe function) MPORT is static and cannot change. If this
76  * RTE ethdev gets plugged back, the entry will be reused, and
77  * RTE switch port ID will be the same.
78  */
79 struct sfc_mae_switch_domain {
80 	TAILQ_ENTRY(sfc_mae_switch_domain)	entries;
81 
82 	/** HW switch ID */
83 	struct sfc_hw_switch_id			*hw_switch_id;
84 	/** The number of ports in the switch port registry */
85 	unsigned int				nb_ports;
86 	/** Switch port registry */
87 	struct sfc_mae_switch_ports		ports;
88 	/** RTE switch domain ID allocated for a group of devices */
89 	uint16_t				id;
90 };
91 
92 TAILQ_HEAD(sfc_mae_switch_domains, sfc_mae_switch_domain);
93 
94 /**
95  * MAE representation of RTE switch infrastructure.
96  *
97  * It is possible that an RTE flow API client tries to insert a rule
98  * referencing an RTE ethdev deployed on top of a different physical
99  * device (it may belong to the same vendor or not). This particular
100  * driver/engine cannot support this and has to turn down such rules.
101  *
102  * Technically, it's HW switch identifier which, if queried for each
103  * RTE ethdev instance, indicates relationship between the instances.
104  * In the meantime, RTE flow API clients also need to somehow figure
105  * out relationship between RTE ethdev instances in advance.
106  *
107  * The concept of RTE switch domains resolves this issue. The driver
108  * maintains a static list of switch domains which is easy to browse,
109  * and each RTE ethdev fills RTE switch parameters in device
110  * information structure which is made available to clients.
111  *
112  * Even if all RTE ethdev instances belonging to a switch domain get
113  * unplugged, the corresponding entry in the switch domain registry
114  * will not be removed because the corresponding HW switch exists
115  * regardless of its ports being plugged to DPDK or kept aside.
116  * If a port gets plugged back to DPDK, the corresponding
117  * RTE ethdev will indicate the same RTE switch domain ID.
118  */
119 struct sfc_mae_switch {
120 	/** A lock to protect the whole structure */
121 	rte_spinlock_t			lock;
122 	/** Switch domain registry */
123 	struct sfc_mae_switch_domains	domains;
124 };
125 
126 static struct sfc_mae_switch sfc_mae_switch = {
127 	.lock = RTE_SPINLOCK_INITIALIZER,
128 	.domains = TAILQ_HEAD_INITIALIZER(sfc_mae_switch.domains),
129 };
130 
131 
132 /* This function expects to be called only when the lock is held */
133 static struct sfc_mae_switch_domain *
134 sfc_mae_find_switch_domain_by_id(uint16_t switch_domain_id)
135 {
136 	struct sfc_mae_switch_domain *domain;
137 
138 	SFC_ASSERT(rte_spinlock_is_locked(&sfc_mae_switch.lock));
139 
140 	TAILQ_FOREACH(domain, &sfc_mae_switch.domains, entries) {
141 		if (domain->id == switch_domain_id)
142 			return domain;
143 	}
144 
145 	return NULL;
146 }
147 
148 /* This function expects to be called only when the lock is held */
149 static struct sfc_mae_switch_domain *
150 sfc_mae_find_switch_domain_by_hw_switch_id(const struct sfc_hw_switch_id *id)
151 {
152 	struct sfc_mae_switch_domain *domain;
153 
154 	SFC_ASSERT(rte_spinlock_is_locked(&sfc_mae_switch.lock));
155 
156 	TAILQ_FOREACH(domain, &sfc_mae_switch.domains, entries) {
157 		if (sfc_hw_switch_ids_equal(domain->hw_switch_id, id))
158 			return domain;
159 	}
160 
161 	return NULL;
162 }
163 
164 int
165 sfc_mae_assign_switch_domain(struct sfc_adapter *sa,
166 			     uint16_t *switch_domain_id)
167 {
168 	struct sfc_hw_switch_id *hw_switch_id;
169 	struct sfc_mae_switch_domain *domain;
170 	int rc;
171 
172 	rte_spinlock_lock(&sfc_mae_switch.lock);
173 
174 	rc = sfc_hw_switch_id_init(sa, &hw_switch_id);
175 	if (rc != 0)
176 		goto fail_hw_switch_id_init;
177 
178 	domain = sfc_mae_find_switch_domain_by_hw_switch_id(hw_switch_id);
179 	if (domain != NULL) {
180 		sfc_hw_switch_id_fini(sa, hw_switch_id);
181 		goto done;
182 	}
183 
184 	domain = rte_zmalloc("sfc_mae_switch_domain", sizeof(*domain), 0);
185 	if (domain == NULL) {
186 		rc = ENOMEM;
187 		goto fail_mem_alloc;
188 	}
189 
190 	/*
191 	 * This code belongs to driver init path, that is, negation is
192 	 * done at the end of the path by sfc_eth_dev_init(). RTE APIs
193 	 * negate error codes, so drop negation here.
194 	 */
195 	rc = -rte_eth_switch_domain_alloc(&domain->id);
196 	if (rc != 0)
197 		goto fail_domain_alloc;
198 
199 	domain->hw_switch_id = hw_switch_id;
200 
201 	TAILQ_INIT(&domain->ports);
202 
203 	TAILQ_INSERT_TAIL(&sfc_mae_switch.domains, domain, entries);
204 
205 done:
206 	*switch_domain_id = domain->id;
207 
208 	rte_spinlock_unlock(&sfc_mae_switch.lock);
209 
210 	return 0;
211 
212 fail_domain_alloc:
213 	rte_free(domain);
214 
215 fail_mem_alloc:
216 	sfc_hw_switch_id_fini(sa, hw_switch_id);
217 	rte_spinlock_unlock(&sfc_mae_switch.lock);
218 
219 fail_hw_switch_id_init:
220 	return rc;
221 }
222 
223 /* This function expects to be called only when the lock is held */
224 static struct sfc_mae_switch_port *
225 sfc_mae_find_switch_port_by_entity(const struct sfc_mae_switch_domain *domain,
226 				   const efx_mport_sel_t *entity_mportp,
227 				   enum sfc_mae_switch_port_type type)
228 {
229 	struct sfc_mae_switch_port *port;
230 
231 	SFC_ASSERT(rte_spinlock_is_locked(&sfc_mae_switch.lock));
232 
233 	TAILQ_FOREACH(port, &domain->ports, switch_domain_ports) {
234 		if (port->entity_mport.sel == entity_mportp->sel &&
235 		    port->type == type)
236 			return port;
237 	}
238 
239 	return NULL;
240 }
241 
242 int
243 sfc_mae_assign_switch_port(uint16_t switch_domain_id,
244 			   const struct sfc_mae_switch_port_request *req,
245 			   uint16_t *switch_port_id)
246 {
247 	struct sfc_mae_switch_domain *domain;
248 	struct sfc_mae_switch_port *port;
249 	int rc;
250 
251 	rte_spinlock_lock(&sfc_mae_switch.lock);
252 
253 	domain = sfc_mae_find_switch_domain_by_id(switch_domain_id);
254 	if (domain == NULL) {
255 		rc = EINVAL;
256 		goto fail_find_switch_domain_by_id;
257 	}
258 
259 	port = sfc_mae_find_switch_port_by_entity(domain, req->entity_mportp,
260 						  req->type);
261 	if (port != NULL)
262 		goto done;
263 
264 	port = rte_zmalloc("sfc_mae_switch_port", sizeof(*port), 0);
265 	if (port == NULL) {
266 		rc = ENOMEM;
267 		goto fail_mem_alloc;
268 	}
269 
270 	port->entity_mport.sel = req->entity_mportp->sel;
271 	port->type = req->type;
272 
273 	port->id = (domain->nb_ports++);
274 
275 	TAILQ_INSERT_TAIL(&domain->ports, port, switch_domain_ports);
276 
277 done:
278 	port->ethdev_mport = *req->ethdev_mportp;
279 	port->ethdev_port_id = req->ethdev_port_id;
280 
281 	*switch_port_id = port->id;
282 
283 	rte_spinlock_unlock(&sfc_mae_switch.lock);
284 
285 	return 0;
286 
287 fail_mem_alloc:
288 fail_find_switch_domain_by_id:
289 	rte_spinlock_unlock(&sfc_mae_switch.lock);
290 	return rc;
291 }
292 
293 /* This function expects to be called only when the lock is held */
294 static int
295 sfc_mae_find_switch_port_by_ethdev(uint16_t switch_domain_id,
296 				   uint16_t ethdev_port_id,
297 				   efx_mport_sel_t *mport_sel)
298 {
299 	struct sfc_mae_switch_domain *domain;
300 	struct sfc_mae_switch_port *port;
301 
302 	SFC_ASSERT(rte_spinlock_is_locked(&sfc_mae_switch.lock));
303 
304 	if (ethdev_port_id == RTE_MAX_ETHPORTS)
305 		return EINVAL;
306 
307 	domain = sfc_mae_find_switch_domain_by_id(switch_domain_id);
308 	if (domain == NULL)
309 		return EINVAL;
310 
311 	TAILQ_FOREACH(port, &domain->ports, switch_domain_ports) {
312 		if (port->ethdev_port_id == ethdev_port_id) {
313 			*mport_sel = port->ethdev_mport;
314 			return 0;
315 		}
316 	}
317 
318 	return ENOENT;
319 }
320 
321 int
322 sfc_mae_switch_port_by_ethdev(uint16_t switch_domain_id,
323 			      uint16_t ethdev_port_id,
324 			      efx_mport_sel_t *mport_sel)
325 {
326 	int rc;
327 
328 	rte_spinlock_lock(&sfc_mae_switch.lock);
329 	rc = sfc_mae_find_switch_port_by_ethdev(switch_domain_id,
330 						ethdev_port_id, mport_sel);
331 	rte_spinlock_unlock(&sfc_mae_switch.lock);
332 
333 	return rc;
334 }
335