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