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
46static void smc_ism_create_system_eid(void)
47{
48 struct smc_ism_seid *seid =
49 (struct smc_ism_seid *)smc_ism_v2_system_eid;
50#if IS_ENABLED(CONFIG_S390)
51 struct cpuid id;
52 u16 ident_tail;
53 char tmp[5];
54
55 memcpy(seid->seid_string, "IBM-SYSZ-ISMSEID00000000", 24);
56 get_cpu_id(&id);
57 ident_tail = (u16)(id.ident & SMC_ISM_IDENT_MASK);
58 snprintf(tmp, 5, "%04X", ident_tail);
59 memcpy(seid->serial_number, tmp, 4);
60 snprintf(tmp, 5, "%04X", id.machine);
61 memcpy(seid->type, tmp, 4);
62#else
63 memset(seid, 0, SMC_MAX_EID_LEN);
64#endif
65}
66
67/* Test if an ISM communication is possible - same CPC */
68int smc_ism_cantalk(struct smcd_gid *peer_gid, unsigned short vlan_id,
69 struct smcd_dev *smcd)
70{
71 return smcd->ops->query_remote_gid(smcd, peer_gid, vlan_id ? 1 : 0,
72 vlan_id);
73}
74
75void smc_ism_get_system_eid(u8 **eid)
76{
77 if (!smc_ism_v2_capable)
78 *eid = NULL;
79 else
80 *eid = smc_ism_v2_system_eid;
81}
82
83u16 smc_ism_get_chid(struct smcd_dev *smcd)
84{
85 return smcd->ops->get_chid(smcd);
86}
87
88/* HW supports ISM V2 and thus System EID is defined */
89bool smc_ism_is_v2_capable(void)
90{
91 return smc_ism_v2_capable;
92}
93
94/* Set a connection using this DMBE. */
95void smc_ism_set_conn(struct smc_connection *conn)
96{
97 unsigned long flags;
98
99 spin_lock_irqsave(&conn->lgr->smcd->lock, flags);
100 conn->lgr->smcd->conn[conn->rmb_desc->sba_idx] = conn;
101 spin_unlock_irqrestore(lock: &conn->lgr->smcd->lock, flags);
102}
103
104/* Unset a connection using this DMBE. */
105void smc_ism_unset_conn(struct smc_connection *conn)
106{
107 unsigned long flags;
108
109 if (!conn->rmb_desc)
110 return;
111
112 spin_lock_irqsave(&conn->lgr->smcd->lock, flags);
113 conn->lgr->smcd->conn[conn->rmb_desc->sba_idx] = NULL;
114 spin_unlock_irqrestore(lock: &conn->lgr->smcd->lock, flags);
115}
116
117/* Register a VLAN identifier with the ISM device. Use a reference count
118 * and add a VLAN identifier only when the first DMB using this VLAN is
119 * registered.
120 */
121int smc_ism_get_vlan(struct smcd_dev *smcd, unsigned short vlanid)
122{
123 struct smc_ism_vlanid *new_vlan, *vlan;
124 unsigned long flags;
125 int rc = 0;
126
127 if (!vlanid) /* No valid vlan id */
128 return -EINVAL;
129
130 /* create new vlan entry, in case we need it */
131 new_vlan = kzalloc(size: sizeof(*new_vlan), GFP_KERNEL);
132 if (!new_vlan)
133 return -ENOMEM;
134 new_vlan->vlanid = vlanid;
135 refcount_set(r: &new_vlan->refcnt, n: 1);
136
137 /* if there is an existing entry, increase count and return */
138 spin_lock_irqsave(&smcd->lock, flags);
139 list_for_each_entry(vlan, &smcd->vlan, list) {
140 if (vlan->vlanid == vlanid) {
141 refcount_inc(r: &vlan->refcnt);
142 kfree(objp: new_vlan);
143 goto out;
144 }
145 }
146
147 /* no existing entry found.
148 * add new entry to device; might fail, e.g., if HW limit reached
149 */
150 if (smcd->ops->add_vlan_id(smcd, vlanid)) {
151 kfree(objp: new_vlan);
152 rc = -EIO;
153 goto out;
154 }
155 list_add_tail(new: &new_vlan->list, head: &smcd->vlan);
156out:
157 spin_unlock_irqrestore(lock: &smcd->lock, flags);
158 return rc;
159}
160
161/* Unregister a VLAN identifier with the ISM device. Use a reference count
162 * and remove a VLAN identifier only when the last DMB using this VLAN is
163 * unregistered.
164 */
165int smc_ism_put_vlan(struct smcd_dev *smcd, unsigned short vlanid)
166{
167 struct smc_ism_vlanid *vlan;
168 unsigned long flags;
169 bool found = false;
170 int rc = 0;
171
172 if (!vlanid) /* No valid vlan id */
173 return -EINVAL;
174
175 spin_lock_irqsave(&smcd->lock, flags);
176 list_for_each_entry(vlan, &smcd->vlan, list) {
177 if (vlan->vlanid == vlanid) {
178 if (!refcount_dec_and_test(r: &vlan->refcnt))
179 goto out;
180 found = true;
181 break;
182 }
183 }
184 if (!found) {
185 rc = -ENOENT;
186 goto out; /* VLAN id not in table */
187 }
188
189 /* Found and the last reference just gone */
190 if (smcd->ops->del_vlan_id(smcd, vlanid))
191 rc = -EIO;
192 list_del(entry: &vlan->list);
193 kfree(objp: vlan);
194out:
195 spin_unlock_irqrestore(lock: &smcd->lock, flags);
196 return rc;
197}
198
199int smc_ism_unregister_dmb(struct smcd_dev *smcd, struct smc_buf_desc *dmb_desc)
200{
201 struct smcd_dmb dmb;
202 int rc = 0;
203
204 if (!dmb_desc->dma_addr)
205 return rc;
206
207 memset(&dmb, 0, sizeof(dmb));
208 dmb.dmb_tok = dmb_desc->token;
209 dmb.sba_idx = dmb_desc->sba_idx;
210 dmb.cpu_addr = dmb_desc->cpu_addr;
211 dmb.dma_addr = dmb_desc->dma_addr;
212 dmb.dmb_len = dmb_desc->len;
213 rc = smcd->ops->unregister_dmb(smcd, &dmb);
214 if (!rc || rc == ISM_ERROR) {
215 dmb_desc->cpu_addr = NULL;
216 dmb_desc->dma_addr = 0;
217 }
218
219 return rc;
220}
221
222int smc_ism_register_dmb(struct smc_link_group *lgr, int dmb_len,
223 struct smc_buf_desc *dmb_desc)
224{
225#if IS_ENABLED(CONFIG_ISM)
226 struct smcd_dmb dmb;
227 int rc;
228
229 memset(&dmb, 0, sizeof(dmb));
230 dmb.dmb_len = dmb_len;
231 dmb.sba_idx = dmb_desc->sba_idx;
232 dmb.vlan_id = lgr->vlan_id;
233 dmb.rgid = lgr->peer_gid.gid;
234 rc = lgr->smcd->ops->register_dmb(lgr->smcd, &dmb, &smc_ism_client);
235 if (!rc) {
236 dmb_desc->sba_idx = dmb.sba_idx;
237 dmb_desc->token = dmb.dmb_tok;
238 dmb_desc->cpu_addr = dmb.cpu_addr;
239 dmb_desc->dma_addr = dmb.dma_addr;
240 dmb_desc->len = dmb.dmb_len;
241 }
242 return rc;
243#else
244 return 0;
245#endif
246}
247
248static int smc_nl_handle_smcd_dev(struct smcd_dev *smcd,
249 struct sk_buff *skb,
250 struct netlink_callback *cb)
251{
252 char smc_pnet[SMC_MAX_PNETID_LEN + 1];
253 struct smc_pci_dev smc_pci_dev;
254 struct nlattr *port_attrs;
255 struct nlattr *attrs;
256 struct ism_dev *ism;
257 int use_cnt = 0;
258 void *nlh;
259
260 ism = smcd->priv;
261 nlh = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, seq: cb->nlh->nlmsg_seq,
262 family: &smc_gen_nl_family, NLM_F_MULTI,
263 cmd: SMC_NETLINK_GET_DEV_SMCD);
264 if (!nlh)
265 goto errmsg;
266 attrs = nla_nest_start(skb, attrtype: SMC_GEN_DEV_SMCD);
267 if (!attrs)
268 goto errout;
269 use_cnt = atomic_read(v: &smcd->lgr_cnt);
270 if (nla_put_u32(skb, attrtype: SMC_NLA_DEV_USE_CNT, value: use_cnt))
271 goto errattr;
272 if (nla_put_u8(skb, attrtype: SMC_NLA_DEV_IS_CRIT, value: use_cnt > 0))
273 goto errattr;
274 memset(&smc_pci_dev, 0, sizeof(smc_pci_dev));
275 smc_set_pci_values(to_pci_dev(ism->dev.parent), smc_dev: &smc_pci_dev);
276 if (nla_put_u32(skb, attrtype: SMC_NLA_DEV_PCI_FID, value: smc_pci_dev.pci_fid))
277 goto errattr;
278 if (nla_put_u16(skb, attrtype: SMC_NLA_DEV_PCI_CHID, value: smc_pci_dev.pci_pchid))
279 goto errattr;
280 if (nla_put_u16(skb, attrtype: SMC_NLA_DEV_PCI_VENDOR, value: smc_pci_dev.pci_vendor))
281 goto errattr;
282 if (nla_put_u16(skb, attrtype: SMC_NLA_DEV_PCI_DEVICE, value: smc_pci_dev.pci_device))
283 goto errattr;
284 if (nla_put_string(skb, attrtype: SMC_NLA_DEV_PCI_ID, str: smc_pci_dev.pci_id))
285 goto errattr;
286
287 port_attrs = nla_nest_start(skb, attrtype: SMC_NLA_DEV_PORT);
288 if (!port_attrs)
289 goto errattr;
290 if (nla_put_u8(skb, attrtype: SMC_NLA_DEV_PORT_PNET_USR, value: smcd->pnetid_by_user))
291 goto errportattr;
292 memcpy(smc_pnet, smcd->pnetid, SMC_MAX_PNETID_LEN);
293 smc_pnet[SMC_MAX_PNETID_LEN] = 0;
294 if (nla_put_string(skb, attrtype: SMC_NLA_DEV_PORT_PNETID, str: smc_pnet))
295 goto errportattr;
296
297 nla_nest_end(skb, start: port_attrs);
298 nla_nest_end(skb, start: attrs);
299 genlmsg_end(skb, hdr: nlh);
300 return 0;
301
302errportattr:
303 nla_nest_cancel(skb, start: port_attrs);
304errattr:
305 nla_nest_cancel(skb, start: attrs);
306errout:
307 nlmsg_cancel(skb, nlh);
308errmsg:
309 return -EMSGSIZE;
310}
311
312static void smc_nl_prep_smcd_dev(struct smcd_dev_list *dev_list,
313 struct sk_buff *skb,
314 struct netlink_callback *cb)
315{
316 struct smc_nl_dmp_ctx *cb_ctx = smc_nl_dmp_ctx(c: cb);
317 int snum = cb_ctx->pos[0];
318 struct smcd_dev *smcd;
319 int num = 0;
320
321 mutex_lock(&dev_list->mutex);
322 list_for_each_entry(smcd, &dev_list->list, list) {
323 if (num < snum)
324 goto next;
325 if (smc_nl_handle_smcd_dev(smcd, skb, cb))
326 goto errout;
327next:
328 num++;
329 }
330errout:
331 mutex_unlock(lock: &dev_list->mutex);
332 cb_ctx->pos[0] = num;
333}
334
335int smcd_nl_get_device(struct sk_buff *skb, struct netlink_callback *cb)
336{
337 smc_nl_prep_smcd_dev(dev_list: &smcd_dev_list, skb, cb);
338 return skb->len;
339}
340
341#if IS_ENABLED(CONFIG_ISM)
342struct smc_ism_event_work {
343 struct work_struct work;
344 struct smcd_dev *smcd;
345 struct ism_event event;
346};
347
348#define ISM_EVENT_REQUEST 0x0001
349#define ISM_EVENT_RESPONSE 0x0002
350#define ISM_EVENT_REQUEST_IR 0x00000001
351#define ISM_EVENT_CODE_SHUTDOWN 0x80
352#define ISM_EVENT_CODE_TESTLINK 0x83
353
354union smcd_sw_event_info {
355 u64 info;
356 struct {
357 u8 uid[SMC_LGR_ID_SIZE];
358 unsigned short vlan_id;
359 u16 code;
360 };
361};
362
363static void smcd_handle_sw_event(struct smc_ism_event_work *wrk)
364{
365 struct smcd_gid peer_gid = { .gid = wrk->event.tok,
366 .gid_ext = 0 };
367 union smcd_sw_event_info ev_info;
368
369 ev_info.info = wrk->event.info;
370 switch (wrk->event.code) {
371 case ISM_EVENT_CODE_SHUTDOWN: /* Peer shut down DMBs */
372 smc_smcd_terminate(wrk->smcd, &peer_gid, ev_info.vlan_id);
373 break;
374 case ISM_EVENT_CODE_TESTLINK: /* Activity timer */
375 if (ev_info.code == ISM_EVENT_REQUEST) {
376 ev_info.code = ISM_EVENT_RESPONSE;
377 wrk->smcd->ops->signal_event(wrk->smcd,
378 &peer_gid,
379 ISM_EVENT_REQUEST_IR,
380 ISM_EVENT_CODE_TESTLINK,
381 ev_info.info);
382 }
383 break;
384 }
385}
386
387/* worker for SMC-D events */
388static void smc_ism_event_work(struct work_struct *work)
389{
390 struct smc_ism_event_work *wrk =
391 container_of(work, struct smc_ism_event_work, work);
392 struct smcd_gid smcd_gid = { .gid = wrk->event.tok,
393 .gid_ext = 0 };
394
395 switch (wrk->event.type) {
396 case ISM_EVENT_GID: /* GID event, token is peer GID */
397 smc_smcd_terminate(wrk->smcd, &smcd_gid, VLAN_VID_MASK);
398 break;
399 case ISM_EVENT_DMB:
400 break;
401 case ISM_EVENT_SWR: /* Software defined event */
402 smcd_handle_sw_event(wrk);
403 break;
404 }
405 kfree(wrk);
406}
407
408static struct smcd_dev *smcd_alloc_dev(struct device *parent, const char *name,
409 const struct smcd_ops *ops, int max_dmbs)
410{
411 struct smcd_dev *smcd;
412
413 smcd = devm_kzalloc(parent, sizeof(*smcd), GFP_KERNEL);
414 if (!smcd)
415 return NULL;
416 smcd->conn = devm_kcalloc(parent, max_dmbs,
417 sizeof(struct smc_connection *), GFP_KERNEL);
418 if (!smcd->conn)
419 return NULL;
420
421 smcd->event_wq = alloc_ordered_workqueue("ism_evt_wq-%s)",
422 WQ_MEM_RECLAIM, name);
423 if (!smcd->event_wq)
424 return NULL;
425
426 smcd->ops = ops;
427
428 spin_lock_init(&smcd->lock);
429 spin_lock_init(&smcd->lgr_lock);
430 INIT_LIST_HEAD(&smcd->vlan);
431 INIT_LIST_HEAD(&smcd->lgr_list);
432 init_waitqueue_head(&smcd->lgrs_deleted);
433 return smcd;
434}
435
436static void smcd_register_dev(struct ism_dev *ism)
437{
438 const struct smcd_ops *ops = ism_get_smcd_ops();
439 struct smcd_dev *smcd;
440
441 if (!ops)
442 return;
443
444 smcd = smcd_alloc_dev(&ism->pdev->dev, dev_name(&ism->pdev->dev), ops,
445 ISM_NR_DMBS);
446 if (!smcd)
447 return;
448 smcd->priv = ism;
449 ism_set_priv(ism, &smc_ism_client, smcd);
450 if (smc_pnetid_by_dev_port(&ism->pdev->dev, 0, smcd->pnetid))
451 smc_pnetid_by_table_smcd(smcd);
452
453 mutex_lock(&smcd_dev_list.mutex);
454 if (list_empty(&smcd_dev_list.list)) {
455 if (smcd->ops->supports_v2())
456 smc_ism_v2_capable = true;
457 }
458 /* sort list: devices without pnetid before devices with pnetid */
459 if (smcd->pnetid[0])
460 list_add_tail(&smcd->list, &smcd_dev_list.list);
461 else
462 list_add(&smcd->list, &smcd_dev_list.list);
463 mutex_unlock(&smcd_dev_list.mutex);
464
465 pr_warn_ratelimited("smc: adding smcd device %s with pnetid %.16s%s\n",
466 dev_name(&ism->dev), smcd->pnetid,
467 smcd->pnetid_by_user ? " (user defined)" : "");
468
469 return;
470}
471
472static void smcd_unregister_dev(struct ism_dev *ism)
473{
474 struct smcd_dev *smcd = ism_get_priv(ism, &smc_ism_client);
475
476 pr_warn_ratelimited("smc: removing smcd device %s\n",
477 dev_name(&ism->dev));
478 smcd->going_away = 1;
479 smc_smcd_terminate_all(smcd);
480 mutex_lock(&smcd_dev_list.mutex);
481 list_del_init(&smcd->list);
482 mutex_unlock(&smcd_dev_list.mutex);
483 destroy_workqueue(smcd->event_wq);
484}
485
486/* SMCD Device event handler. Called from ISM device interrupt handler.
487 * Parameters are ism device pointer,
488 * - event->type (0 --> DMB, 1 --> GID),
489 * - event->code (event code),
490 * - event->tok (either DMB token when event type 0, or GID when event type 1)
491 * - event->time (time of day)
492 * - event->info (debug info).
493 *
494 * Context:
495 * - Function called in IRQ context from ISM device driver event handler.
496 */
497static void smcd_handle_event(struct ism_dev *ism, struct ism_event *event)
498{
499 struct smcd_dev *smcd = ism_get_priv(ism, &smc_ism_client);
500 struct smc_ism_event_work *wrk;
501
502 if (smcd->going_away)
503 return;
504 /* copy event to event work queue, and let it be handled there */
505 wrk = kmalloc(sizeof(*wrk), GFP_ATOMIC);
506 if (!wrk)
507 return;
508 INIT_WORK(&wrk->work, smc_ism_event_work);
509 wrk->smcd = smcd;
510 wrk->event = *event;
511 queue_work(smcd->event_wq, &wrk->work);
512}
513
514/* SMCD Device interrupt handler. Called from ISM device interrupt handler.
515 * Parameters are the ism device pointer, DMB number, and the DMBE bitmask.
516 * Find the connection and schedule the tasklet for this connection.
517 *
518 * Context:
519 * - Function called in IRQ context from ISM device driver IRQ handler.
520 */
521static void smcd_handle_irq(struct ism_dev *ism, unsigned int dmbno,
522 u16 dmbemask)
523{
524 struct smcd_dev *smcd = ism_get_priv(ism, &smc_ism_client);
525 struct smc_connection *conn = NULL;
526 unsigned long flags;
527
528 spin_lock_irqsave(&smcd->lock, flags);
529 conn = smcd->conn[dmbno];
530 if (conn && !conn->killed)
531 tasklet_schedule(&conn->rx_tsklet);
532 spin_unlock_irqrestore(&smcd->lock, flags);
533}
534#endif
535
536int smc_ism_signal_shutdown(struct smc_link_group *lgr)
537{
538 int rc = 0;
539#if IS_ENABLED(CONFIG_ISM)
540 union smcd_sw_event_info ev_info;
541
542 if (lgr->peer_shutdown)
543 return 0;
544
545 memcpy(ev_info.uid, lgr->id, SMC_LGR_ID_SIZE);
546 ev_info.vlan_id = lgr->vlan_id;
547 ev_info.code = ISM_EVENT_REQUEST;
548 rc = lgr->smcd->ops->signal_event(lgr->smcd, &lgr->peer_gid,
549 ISM_EVENT_REQUEST_IR,
550 ISM_EVENT_CODE_SHUTDOWN,
551 ev_info.info);
552#endif
553 return rc;
554}
555
556int smc_ism_init(void)
557{
558 int rc = 0;
559
560 smc_ism_v2_capable = false;
561 smc_ism_create_system_eid();
562
563#if IS_ENABLED(CONFIG_ISM)
564 rc = ism_register_client(&smc_ism_client);
565#endif
566 return rc;
567}
568
569void smc_ism_exit(void)
570{
571#if IS_ENABLED(CONFIG_ISM)
572 ism_unregister_client(&smc_ism_client);
573#endif
574}
575

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