1 // SPDX-License-Identifier: GPL-2.0
2 /* Shared Memory Communications Direct over ISM devices (SMC-D)
3  *
4  * Functions for ISM device.
5  *
6  * Copyright IBM Corp. 2018
7  */
8 
9 #include <linux/if_vlan.h>
10 #include <linux/spinlock.h>
11 #include <linux/mutex.h>
12 #include <linux/slab.h>
13 #include <asm/page.h>
14 
15 #include "smc.h"
16 #include "smc_core.h"
17 #include "smc_ism.h"
18 #include "smc_pnet.h"
19 #include "smc_netlink.h"
20 #include "linux/ism.h"
21 
22 struct smcd_dev_list smcd_dev_list = {
23 	.list = LIST_HEAD_INIT(smcd_dev_list.list),
24 	.mutex = __MUTEX_INITIALIZER(smcd_dev_list.mutex)
25 };
26 
27 static bool smc_ism_v2_capable;
28 static u8 smc_ism_v2_system_eid[SMC_MAX_EID_LEN];
29 
30 #if IS_ENABLED(CONFIG_ISM)
31 static void smcd_register_dev(struct ism_dev *ism);
32 static void smcd_unregister_dev(struct ism_dev *ism);
33 static void smcd_handle_event(struct ism_dev *ism, struct ism_event *event);
34 static void smcd_handle_irq(struct ism_dev *ism, unsigned int dmbno,
35 			    u16 dmbemask);
36 
37 static struct ism_client smc_ism_client = {
38 	.name = "SMC-D",
39 	.add = smcd_register_dev,
40 	.remove = smcd_unregister_dev,
41 	.handle_event = smcd_handle_event,
42 	.handle_irq = smcd_handle_irq,
43 };
44 #endif
45 
46 /* Test if an ISM communication is possible - same CPC */
smc_ism_cantalk(u64 peer_gid,unsigned short vlan_id,struct smcd_dev * smcd)47 int smc_ism_cantalk(u64 peer_gid, unsigned short vlan_id, struct smcd_dev *smcd)
48 {
49 	return smcd->ops->query_remote_gid(smcd, peer_gid, vlan_id ? 1 : 0,
50 					   vlan_id);
51 }
52 
smc_ism_get_system_eid(u8 ** eid)53 void smc_ism_get_system_eid(u8 **eid)
54 {
55 	if (!smc_ism_v2_capable)
56 		*eid = NULL;
57 	else
58 		*eid = smc_ism_v2_system_eid;
59 }
60 
smc_ism_get_chid(struct smcd_dev * smcd)61 u16 smc_ism_get_chid(struct smcd_dev *smcd)
62 {
63 	return smcd->ops->get_chid(smcd);
64 }
65 
66 /* HW supports ISM V2 and thus System EID is defined */
smc_ism_is_v2_capable(void)67 bool smc_ism_is_v2_capable(void)
68 {
69 	return smc_ism_v2_capable;
70 }
71 
72 /* Set a connection using this DMBE. */
smc_ism_set_conn(struct smc_connection * conn)73 void smc_ism_set_conn(struct smc_connection *conn)
74 {
75 	unsigned long flags;
76 
77 	spin_lock_irqsave(&conn->lgr->smcd->lock, flags);
78 	conn->lgr->smcd->conn[conn->rmb_desc->sba_idx] = conn;
79 	spin_unlock_irqrestore(&conn->lgr->smcd->lock, flags);
80 }
81 
82 /* Unset a connection using this DMBE. */
smc_ism_unset_conn(struct smc_connection * conn)83 void smc_ism_unset_conn(struct smc_connection *conn)
84 {
85 	unsigned long flags;
86 
87 	if (!conn->rmb_desc)
88 		return;
89 
90 	spin_lock_irqsave(&conn->lgr->smcd->lock, flags);
91 	conn->lgr->smcd->conn[conn->rmb_desc->sba_idx] = NULL;
92 	spin_unlock_irqrestore(&conn->lgr->smcd->lock, flags);
93 }
94 
95 /* Register a VLAN identifier with the ISM device. Use a reference count
96  * and add a VLAN identifier only when the first DMB using this VLAN is
97  * registered.
98  */
smc_ism_get_vlan(struct smcd_dev * smcd,unsigned short vlanid)99 int smc_ism_get_vlan(struct smcd_dev *smcd, unsigned short vlanid)
100 {
101 	struct smc_ism_vlanid *new_vlan, *vlan;
102 	unsigned long flags;
103 	int rc = 0;
104 
105 	if (!vlanid)			/* No valid vlan id */
106 		return -EINVAL;
107 
108 	/* create new vlan entry, in case we need it */
109 	new_vlan = kzalloc(sizeof(*new_vlan), GFP_KERNEL);
110 	if (!new_vlan)
111 		return -ENOMEM;
112 	new_vlan->vlanid = vlanid;
113 	refcount_set(&new_vlan->refcnt, 1);
114 
115 	/* if there is an existing entry, increase count and return */
116 	spin_lock_irqsave(&smcd->lock, flags);
117 	list_for_each_entry(vlan, &smcd->vlan, list) {
118 		if (vlan->vlanid == vlanid) {
119 			refcount_inc(&vlan->refcnt);
120 			kfree(new_vlan);
121 			goto out;
122 		}
123 	}
124 
125 	/* no existing entry found.
126 	 * add new entry to device; might fail, e.g., if HW limit reached
127 	 */
128 	if (smcd->ops->add_vlan_id(smcd, vlanid)) {
129 		kfree(new_vlan);
130 		rc = -EIO;
131 		goto out;
132 	}
133 	list_add_tail(&new_vlan->list, &smcd->vlan);
134 out:
135 	spin_unlock_irqrestore(&smcd->lock, flags);
136 	return rc;
137 }
138 
139 /* Unregister a VLAN identifier with the ISM device. Use a reference count
140  * and remove a VLAN identifier only when the last DMB using this VLAN is
141  * unregistered.
142  */
smc_ism_put_vlan(struct smcd_dev * smcd,unsigned short vlanid)143 int smc_ism_put_vlan(struct smcd_dev *smcd, unsigned short vlanid)
144 {
145 	struct smc_ism_vlanid *vlan;
146 	unsigned long flags;
147 	bool found = false;
148 	int rc = 0;
149 
150 	if (!vlanid)			/* No valid vlan id */
151 		return -EINVAL;
152 
153 	spin_lock_irqsave(&smcd->lock, flags);
154 	list_for_each_entry(vlan, &smcd->vlan, list) {
155 		if (vlan->vlanid == vlanid) {
156 			if (!refcount_dec_and_test(&vlan->refcnt))
157 				goto out;
158 			found = true;
159 			break;
160 		}
161 	}
162 	if (!found) {
163 		rc = -ENOENT;
164 		goto out;		/* VLAN id not in table */
165 	}
166 
167 	/* Found and the last reference just gone */
168 	if (smcd->ops->del_vlan_id(smcd, vlanid))
169 		rc = -EIO;
170 	list_del(&vlan->list);
171 	kfree(vlan);
172 out:
173 	spin_unlock_irqrestore(&smcd->lock, flags);
174 	return rc;
175 }
176 
smc_ism_unregister_dmb(struct smcd_dev * smcd,struct smc_buf_desc * dmb_desc)177 int smc_ism_unregister_dmb(struct smcd_dev *smcd, struct smc_buf_desc *dmb_desc)
178 {
179 	struct smcd_dmb dmb;
180 	int rc = 0;
181 
182 	if (!dmb_desc->dma_addr)
183 		return rc;
184 
185 	memset(&dmb, 0, sizeof(dmb));
186 	dmb.dmb_tok = dmb_desc->token;
187 	dmb.sba_idx = dmb_desc->sba_idx;
188 	dmb.cpu_addr = dmb_desc->cpu_addr;
189 	dmb.dma_addr = dmb_desc->dma_addr;
190 	dmb.dmb_len = dmb_desc->len;
191 	rc = smcd->ops->unregister_dmb(smcd, &dmb);
192 	if (!rc || rc == ISM_ERROR) {
193 		dmb_desc->cpu_addr = NULL;
194 		dmb_desc->dma_addr = 0;
195 	}
196 
197 	return rc;
198 }
199 
smc_ism_register_dmb(struct smc_link_group * lgr,int dmb_len,struct smc_buf_desc * dmb_desc)200 int smc_ism_register_dmb(struct smc_link_group *lgr, int dmb_len,
201 			 struct smc_buf_desc *dmb_desc)
202 {
203 #if IS_ENABLED(CONFIG_ISM)
204 	struct smcd_dmb dmb;
205 	int rc;
206 
207 	memset(&dmb, 0, sizeof(dmb));
208 	dmb.dmb_len = dmb_len;
209 	dmb.sba_idx = dmb_desc->sba_idx;
210 	dmb.vlan_id = lgr->vlan_id;
211 	dmb.rgid = lgr->peer_gid;
212 	rc = lgr->smcd->ops->register_dmb(lgr->smcd, &dmb, &smc_ism_client);
213 	if (!rc) {
214 		dmb_desc->sba_idx = dmb.sba_idx;
215 		dmb_desc->token = dmb.dmb_tok;
216 		dmb_desc->cpu_addr = dmb.cpu_addr;
217 		dmb_desc->dma_addr = dmb.dma_addr;
218 		dmb_desc->len = dmb.dmb_len;
219 	}
220 	return rc;
221 #else
222 	return 0;
223 #endif
224 }
225 
smc_nl_handle_smcd_dev(struct smcd_dev * smcd,struct sk_buff * skb,struct netlink_callback * cb)226 static int smc_nl_handle_smcd_dev(struct smcd_dev *smcd,
227 				  struct sk_buff *skb,
228 				  struct netlink_callback *cb)
229 {
230 	char smc_pnet[SMC_MAX_PNETID_LEN + 1];
231 	struct smc_pci_dev smc_pci_dev;
232 	struct nlattr *port_attrs;
233 	struct nlattr *attrs;
234 	struct ism_dev *ism;
235 	int use_cnt = 0;
236 	void *nlh;
237 
238 	ism = smcd->priv;
239 	nlh = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
240 			  &smc_gen_nl_family, NLM_F_MULTI,
241 			  SMC_NETLINK_GET_DEV_SMCD);
242 	if (!nlh)
243 		goto errmsg;
244 	attrs = nla_nest_start(skb, SMC_GEN_DEV_SMCD);
245 	if (!attrs)
246 		goto errout;
247 	use_cnt = atomic_read(&smcd->lgr_cnt);
248 	if (nla_put_u32(skb, SMC_NLA_DEV_USE_CNT, use_cnt))
249 		goto errattr;
250 	if (nla_put_u8(skb, SMC_NLA_DEV_IS_CRIT, use_cnt > 0))
251 		goto errattr;
252 	memset(&smc_pci_dev, 0, sizeof(smc_pci_dev));
253 	smc_set_pci_values(to_pci_dev(ism->dev.parent), &smc_pci_dev);
254 	if (nla_put_u32(skb, SMC_NLA_DEV_PCI_FID, smc_pci_dev.pci_fid))
255 		goto errattr;
256 	if (nla_put_u16(skb, SMC_NLA_DEV_PCI_CHID, smc_pci_dev.pci_pchid))
257 		goto errattr;
258 	if (nla_put_u16(skb, SMC_NLA_DEV_PCI_VENDOR, smc_pci_dev.pci_vendor))
259 		goto errattr;
260 	if (nla_put_u16(skb, SMC_NLA_DEV_PCI_DEVICE, smc_pci_dev.pci_device))
261 		goto errattr;
262 	if (nla_put_string(skb, SMC_NLA_DEV_PCI_ID, smc_pci_dev.pci_id))
263 		goto errattr;
264 
265 	port_attrs = nla_nest_start(skb, SMC_NLA_DEV_PORT);
266 	if (!port_attrs)
267 		goto errattr;
268 	if (nla_put_u8(skb, SMC_NLA_DEV_PORT_PNET_USR, smcd->pnetid_by_user))
269 		goto errportattr;
270 	memcpy(smc_pnet, smcd->pnetid, SMC_MAX_PNETID_LEN);
271 	smc_pnet[SMC_MAX_PNETID_LEN] = 0;
272 	if (nla_put_string(skb, SMC_NLA_DEV_PORT_PNETID, smc_pnet))
273 		goto errportattr;
274 
275 	nla_nest_end(skb, port_attrs);
276 	nla_nest_end(skb, attrs);
277 	genlmsg_end(skb, nlh);
278 	return 0;
279 
280 errportattr:
281 	nla_nest_cancel(skb, port_attrs);
282 errattr:
283 	nla_nest_cancel(skb, attrs);
284 errout:
285 	nlmsg_cancel(skb, nlh);
286 errmsg:
287 	return -EMSGSIZE;
288 }
289 
smc_nl_prep_smcd_dev(struct smcd_dev_list * dev_list,struct sk_buff * skb,struct netlink_callback * cb)290 static void smc_nl_prep_smcd_dev(struct smcd_dev_list *dev_list,
291 				 struct sk_buff *skb,
292 				 struct netlink_callback *cb)
293 {
294 	struct smc_nl_dmp_ctx *cb_ctx = smc_nl_dmp_ctx(cb);
295 	int snum = cb_ctx->pos[0];
296 	struct smcd_dev *smcd;
297 	int num = 0;
298 
299 	mutex_lock(&dev_list->mutex);
300 	list_for_each_entry(smcd, &dev_list->list, list) {
301 		if (num < snum)
302 			goto next;
303 		if (smc_nl_handle_smcd_dev(smcd, skb, cb))
304 			goto errout;
305 next:
306 		num++;
307 	}
308 errout:
309 	mutex_unlock(&dev_list->mutex);
310 	cb_ctx->pos[0] = num;
311 }
312 
smcd_nl_get_device(struct sk_buff * skb,struct netlink_callback * cb)313 int smcd_nl_get_device(struct sk_buff *skb, struct netlink_callback *cb)
314 {
315 	smc_nl_prep_smcd_dev(&smcd_dev_list, skb, cb);
316 	return skb->len;
317 }
318 
319 #if IS_ENABLED(CONFIG_ISM)
320 struct smc_ism_event_work {
321 	struct work_struct work;
322 	struct smcd_dev *smcd;
323 	struct ism_event event;
324 };
325 
326 #define ISM_EVENT_REQUEST		0x0001
327 #define ISM_EVENT_RESPONSE		0x0002
328 #define ISM_EVENT_REQUEST_IR		0x00000001
329 #define ISM_EVENT_CODE_SHUTDOWN		0x80
330 #define ISM_EVENT_CODE_TESTLINK		0x83
331 
332 union smcd_sw_event_info {
333 	u64	info;
334 	struct {
335 		u8		uid[SMC_LGR_ID_SIZE];
336 		unsigned short	vlan_id;
337 		u16		code;
338 	};
339 };
340 
smcd_handle_sw_event(struct smc_ism_event_work * wrk)341 static void smcd_handle_sw_event(struct smc_ism_event_work *wrk)
342 {
343 	union smcd_sw_event_info ev_info;
344 
345 	ev_info.info = wrk->event.info;
346 	switch (wrk->event.code) {
347 	case ISM_EVENT_CODE_SHUTDOWN:	/* Peer shut down DMBs */
348 		smc_smcd_terminate(wrk->smcd, wrk->event.tok, ev_info.vlan_id);
349 		break;
350 	case ISM_EVENT_CODE_TESTLINK:	/* Activity timer */
351 		if (ev_info.code == ISM_EVENT_REQUEST) {
352 			ev_info.code = ISM_EVENT_RESPONSE;
353 			wrk->smcd->ops->signal_event(wrk->smcd,
354 						     wrk->event.tok,
355 						     ISM_EVENT_REQUEST_IR,
356 						     ISM_EVENT_CODE_TESTLINK,
357 						     ev_info.info);
358 			}
359 		break;
360 	}
361 }
362 
363 /* worker for SMC-D events */
smc_ism_event_work(struct work_struct * work)364 static void smc_ism_event_work(struct work_struct *work)
365 {
366 	struct smc_ism_event_work *wrk =
367 		container_of(work, struct smc_ism_event_work, work);
368 
369 	switch (wrk->event.type) {
370 	case ISM_EVENT_GID:	/* GID event, token is peer GID */
371 		smc_smcd_terminate(wrk->smcd, wrk->event.tok, VLAN_VID_MASK);
372 		break;
373 	case ISM_EVENT_DMB:
374 		break;
375 	case ISM_EVENT_SWR:	/* Software defined event */
376 		smcd_handle_sw_event(wrk);
377 		break;
378 	}
379 	kfree(wrk);
380 }
381 
smcd_alloc_dev(struct device * parent,const char * name,const struct smcd_ops * ops,int max_dmbs)382 static struct smcd_dev *smcd_alloc_dev(struct device *parent, const char *name,
383 				       const struct smcd_ops *ops, int max_dmbs)
384 {
385 	struct smcd_dev *smcd;
386 
387 	smcd = devm_kzalloc(parent, sizeof(*smcd), GFP_KERNEL);
388 	if (!smcd)
389 		return NULL;
390 	smcd->conn = devm_kcalloc(parent, max_dmbs,
391 				  sizeof(struct smc_connection *), GFP_KERNEL);
392 	if (!smcd->conn)
393 		return NULL;
394 
395 	smcd->event_wq = alloc_ordered_workqueue("ism_evt_wq-%s)",
396 						 WQ_MEM_RECLAIM, name);
397 	if (!smcd->event_wq)
398 		return NULL;
399 
400 	smcd->ops = ops;
401 
402 	spin_lock_init(&smcd->lock);
403 	spin_lock_init(&smcd->lgr_lock);
404 	INIT_LIST_HEAD(&smcd->vlan);
405 	INIT_LIST_HEAD(&smcd->lgr_list);
406 	init_waitqueue_head(&smcd->lgrs_deleted);
407 	return smcd;
408 }
409 
smcd_register_dev(struct ism_dev * ism)410 static void smcd_register_dev(struct ism_dev *ism)
411 {
412 	const struct smcd_ops *ops = ism_get_smcd_ops();
413 	struct smcd_dev *smcd;
414 
415 	if (!ops)
416 		return;
417 
418 	smcd = smcd_alloc_dev(&ism->pdev->dev, dev_name(&ism->pdev->dev), ops,
419 			      ISM_NR_DMBS);
420 	if (!smcd)
421 		return;
422 	smcd->priv = ism;
423 	ism_set_priv(ism, &smc_ism_client, smcd);
424 	if (smc_pnetid_by_dev_port(&ism->pdev->dev, 0, smcd->pnetid))
425 		smc_pnetid_by_table_smcd(smcd);
426 
427 	mutex_lock(&smcd_dev_list.mutex);
428 	if (list_empty(&smcd_dev_list.list)) {
429 		u8 *system_eid = NULL;
430 
431 		system_eid = smcd->ops->get_system_eid();
432 		if (smcd->ops->supports_v2()) {
433 			smc_ism_v2_capable = true;
434 			memcpy(smc_ism_v2_system_eid, system_eid,
435 			       SMC_MAX_EID_LEN);
436 		}
437 	}
438 	/* sort list: devices without pnetid before devices with pnetid */
439 	if (smcd->pnetid[0])
440 		list_add_tail(&smcd->list, &smcd_dev_list.list);
441 	else
442 		list_add(&smcd->list, &smcd_dev_list.list);
443 	mutex_unlock(&smcd_dev_list.mutex);
444 
445 	pr_warn_ratelimited("smc: adding smcd device %s with pnetid %.16s%s\n",
446 			    dev_name(&ism->dev), smcd->pnetid,
447 			    smcd->pnetid_by_user ? " (user defined)" : "");
448 
449 	return;
450 }
451 
smcd_unregister_dev(struct ism_dev * ism)452 static void smcd_unregister_dev(struct ism_dev *ism)
453 {
454 	struct smcd_dev *smcd = ism_get_priv(ism, &smc_ism_client);
455 
456 	pr_warn_ratelimited("smc: removing smcd device %s\n",
457 			    dev_name(&ism->dev));
458 	smcd->going_away = 1;
459 	smc_smcd_terminate_all(smcd);
460 	mutex_lock(&smcd_dev_list.mutex);
461 	list_del_init(&smcd->list);
462 	mutex_unlock(&smcd_dev_list.mutex);
463 	destroy_workqueue(smcd->event_wq);
464 }
465 
466 /* SMCD Device event handler. Called from ISM device interrupt handler.
467  * Parameters are ism device pointer,
468  * - event->type (0 --> DMB, 1 --> GID),
469  * - event->code (event code),
470  * - event->tok (either DMB token when event type 0, or GID when event type 1)
471  * - event->time (time of day)
472  * - event->info (debug info).
473  *
474  * Context:
475  * - Function called in IRQ context from ISM device driver event handler.
476  */
smcd_handle_event(struct ism_dev * ism,struct ism_event * event)477 static void smcd_handle_event(struct ism_dev *ism, struct ism_event *event)
478 {
479 	struct smcd_dev *smcd = ism_get_priv(ism, &smc_ism_client);
480 	struct smc_ism_event_work *wrk;
481 
482 	if (smcd->going_away)
483 		return;
484 	/* copy event to event work queue, and let it be handled there */
485 	wrk = kmalloc(sizeof(*wrk), GFP_ATOMIC);
486 	if (!wrk)
487 		return;
488 	INIT_WORK(&wrk->work, smc_ism_event_work);
489 	wrk->smcd = smcd;
490 	wrk->event = *event;
491 	queue_work(smcd->event_wq, &wrk->work);
492 }
493 
494 /* SMCD Device interrupt handler. Called from ISM device interrupt handler.
495  * Parameters are the ism device pointer, DMB number, and the DMBE bitmask.
496  * Find the connection and schedule the tasklet for this connection.
497  *
498  * Context:
499  * - Function called in IRQ context from ISM device driver IRQ handler.
500  */
smcd_handle_irq(struct ism_dev * ism,unsigned int dmbno,u16 dmbemask)501 static void smcd_handle_irq(struct ism_dev *ism, unsigned int dmbno,
502 			    u16 dmbemask)
503 {
504 	struct smcd_dev *smcd = ism_get_priv(ism, &smc_ism_client);
505 	struct smc_connection *conn = NULL;
506 	unsigned long flags;
507 
508 	spin_lock_irqsave(&smcd->lock, flags);
509 	conn = smcd->conn[dmbno];
510 	if (conn && !conn->killed)
511 		tasklet_schedule(&conn->rx_tsklet);
512 	spin_unlock_irqrestore(&smcd->lock, flags);
513 }
514 #endif
515 
smc_ism_signal_shutdown(struct smc_link_group * lgr)516 int smc_ism_signal_shutdown(struct smc_link_group *lgr)
517 {
518 	int rc = 0;
519 #if IS_ENABLED(CONFIG_ISM)
520 	union smcd_sw_event_info ev_info;
521 
522 	if (lgr->peer_shutdown)
523 		return 0;
524 
525 	memcpy(ev_info.uid, lgr->id, SMC_LGR_ID_SIZE);
526 	ev_info.vlan_id = lgr->vlan_id;
527 	ev_info.code = ISM_EVENT_REQUEST;
528 	rc = lgr->smcd->ops->signal_event(lgr->smcd, lgr->peer_gid,
529 					  ISM_EVENT_REQUEST_IR,
530 					  ISM_EVENT_CODE_SHUTDOWN,
531 					  ev_info.info);
532 #endif
533 	return rc;
534 }
535 
smc_ism_init(void)536 int smc_ism_init(void)
537 {
538 	int rc = 0;
539 
540 #if IS_ENABLED(CONFIG_ISM)
541 	smc_ism_v2_capable = false;
542 	memset(smc_ism_v2_system_eid, 0, SMC_MAX_EID_LEN);
543 
544 	rc = ism_register_client(&smc_ism_client);
545 #endif
546 	return rc;
547 }
548 
smc_ism_exit(void)549 void smc_ism_exit(void)
550 {
551 #if IS_ENABLED(CONFIG_ISM)
552 	ism_unregister_client(&smc_ism_client);
553 #endif
554 }
555