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
22struct 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
27static bool smc_ism_v2_capable;
28static u8 smc_ism_v2_system_eid[SMC_MAX_EID_LEN];
29
30#if IS_ENABLED(CONFIG_ISM)
31static void smcd_register_dev(struct ism_dev *ism);
32static void smcd_unregister_dev(struct ism_dev *ism);
33static void smcd_handle_event(struct ism_dev *ism, struct ism_event *event);
34static void smcd_handle_irq(struct ism_dev *ism, unsigned int dmbno,
35 u16 dmbemask);
36
37static 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 */
47int 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
53void 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
61u16 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 */
67bool smc_ism_is_v2_capable(void)
68{
69 return smc_ism_v2_capable;
70}
71
72/* Set a connection using this DMBE. */
73void 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(lock: &conn->lgr->smcd->lock, flags);
80}
81
82/* Unset a connection using this DMBE. */
83void 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(lock: &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 */
99int 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(size: sizeof(*new_vlan), GFP_KERNEL);
110 if (!new_vlan)
111 return -ENOMEM;
112 new_vlan->vlanid = vlanid;
113 refcount_set(r: &new_vlan->refcnt, n: 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(r: &vlan->refcnt);
120 kfree(objp: 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(objp: new_vlan);
130 rc = -EIO;
131 goto out;
132 }
133 list_add_tail(new: &new_vlan->list, head: &smcd->vlan);
134out:
135 spin_unlock_irqrestore(lock: &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 */
143int 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(r: &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(entry: &vlan->list);
171 kfree(objp: vlan);
172out:
173 spin_unlock_irqrestore(lock: &smcd->lock, flags);
174 return rc;
175}
176
177int 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
200int 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
226static 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, seq: cb->nlh->nlmsg_seq,
240 family: &smc_gen_nl_family, NLM_F_MULTI,
241 cmd: SMC_NETLINK_GET_DEV_SMCD);
242 if (!nlh)
243 goto errmsg;
244 attrs = nla_nest_start(skb, attrtype: SMC_GEN_DEV_SMCD);
245 if (!attrs)
246 goto errout;
247 use_cnt = atomic_read(v: &smcd->lgr_cnt);
248 if (nla_put_u32(skb, attrtype: SMC_NLA_DEV_USE_CNT, value: use_cnt))
249 goto errattr;
250 if (nla_put_u8(skb, attrtype: SMC_NLA_DEV_IS_CRIT, value: 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_dev: &smc_pci_dev);
254 if (nla_put_u32(skb, attrtype: SMC_NLA_DEV_PCI_FID, value: smc_pci_dev.pci_fid))
255 goto errattr;
256 if (nla_put_u16(skb, attrtype: SMC_NLA_DEV_PCI_CHID, value: smc_pci_dev.pci_pchid))
257 goto errattr;
258 if (nla_put_u16(skb, attrtype: SMC_NLA_DEV_PCI_VENDOR, value: smc_pci_dev.pci_vendor))
259 goto errattr;
260 if (nla_put_u16(skb, attrtype: SMC_NLA_DEV_PCI_DEVICE, value: smc_pci_dev.pci_device))
261 goto errattr;
262 if (nla_put_string(skb, attrtype: SMC_NLA_DEV_PCI_ID, str: smc_pci_dev.pci_id))
263 goto errattr;
264
265 port_attrs = nla_nest_start(skb, attrtype: SMC_NLA_DEV_PORT);
266 if (!port_attrs)
267 goto errattr;
268 if (nla_put_u8(skb, attrtype: SMC_NLA_DEV_PORT_PNET_USR, value: 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, attrtype: SMC_NLA_DEV_PORT_PNETID, str: smc_pnet))
273 goto errportattr;
274
275 nla_nest_end(skb, start: port_attrs);
276 nla_nest_end(skb, start: attrs);
277 genlmsg_end(skb, hdr: nlh);
278 return 0;
279
280errportattr:
281 nla_nest_cancel(skb, start: port_attrs);
282errattr:
283 nla_nest_cancel(skb, start: attrs);
284errout:
285 nlmsg_cancel(skb, nlh);
286errmsg:
287 return -EMSGSIZE;
288}
289
290static 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(c: 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;
305next:
306 num++;
307 }
308errout:
309 mutex_unlock(lock: &dev_list->mutex);
310 cb_ctx->pos[0] = num;
311}
312
313int smcd_nl_get_device(struct sk_buff *skb, struct netlink_callback *cb)
314{
315 smc_nl_prep_smcd_dev(dev_list: &smcd_dev_list, skb, cb);
316 return skb->len;
317}
318
319#if IS_ENABLED(CONFIG_ISM)
320struct 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
332union 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
341static 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 */
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 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
410static 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
452static 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 */
477static 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 */
501static 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
516int 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
536int 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
549void smc_ism_exit(void)
550{
551#if IS_ENABLED(CONFIG_ISM)
552 ism_unregister_client(&smc_ism_client);
553#endif
554}
555

source code of linux/net/smc/smc_ism.c