1 // SPDX-License-Identifier: GPL-2.0
2 /* Shared Memory Communications Direct over ISM devices (SMC-D)
4 * Functions for ISM device.
6 * Copyright IBM Corp. 2018
9 #include <linux/spinlock.h>
10 #include <linux/slab.h>
18 struct smcd_dev_list smcd_dev_list = {
19 .list = LIST_HEAD_INIT(smcd_dev_list.list),
20 .lock = __SPIN_LOCK_UNLOCKED(smcd_dev_list.lock)
23 /* Test if an ISM communication is possible. */
24 int smc_ism_cantalk(u64 peer_gid, unsigned short vlan_id, struct smcd_dev *smcd)
26 return smcd->ops->query_remote_gid(smcd, peer_gid, vlan_id ? 1 : 0,
30 int smc_ism_write(struct smcd_dev *smcd, const struct smc_ism_position *pos,
31 void *data, size_t len)
35 rc = smcd->ops->move_data(smcd, pos->token, pos->index, pos->signal,
36 pos->offset, data, len);
38 return rc < 0 ? rc : 0;
41 /* Set a connection using this DMBE. */
42 void smc_ism_set_conn(struct smc_connection *conn)
46 spin_lock_irqsave(&conn->lgr->smcd->lock, flags);
47 conn->lgr->smcd->conn[conn->rmb_desc->sba_idx] = conn;
48 spin_unlock_irqrestore(&conn->lgr->smcd->lock, flags);
51 /* Unset a connection using this DMBE. */
52 void smc_ism_unset_conn(struct smc_connection *conn)
59 spin_lock_irqsave(&conn->lgr->smcd->lock, flags);
60 conn->lgr->smcd->conn[conn->rmb_desc->sba_idx] = NULL;
61 spin_unlock_irqrestore(&conn->lgr->smcd->lock, flags);
64 /* Register a VLAN identifier with the ISM device. Use a reference count
65 * and add a VLAN identifier only when the first DMB using this VLAN is
68 int smc_ism_get_vlan(struct smcd_dev *smcd, unsigned short vlanid)
70 struct smc_ism_vlanid *new_vlan, *vlan;
74 if (!vlanid) /* No valid vlan id */
77 /* create new vlan entry, in case we need it */
78 new_vlan = kzalloc(sizeof(*new_vlan), GFP_KERNEL);
81 new_vlan->vlanid = vlanid;
82 refcount_set(&new_vlan->refcnt, 1);
84 /* if there is an existing entry, increase count and return */
85 spin_lock_irqsave(&smcd->lock, flags);
86 list_for_each_entry(vlan, &smcd->vlan, list) {
87 if (vlan->vlanid == vlanid) {
88 refcount_inc(&vlan->refcnt);
94 /* no existing entry found.
95 * add new entry to device; might fail, e.g., if HW limit reached
97 if (smcd->ops->add_vlan_id(smcd, vlanid)) {
102 list_add_tail(&new_vlan->list, &smcd->vlan);
104 spin_unlock_irqrestore(&smcd->lock, flags);
108 /* Unregister a VLAN identifier with the ISM device. Use a reference count
109 * and remove a VLAN identifier only when the last DMB using this VLAN is
112 int smc_ism_put_vlan(struct smcd_dev *smcd, unsigned short vlanid)
114 struct smc_ism_vlanid *vlan;
119 if (!vlanid) /* No valid vlan id */
122 spin_lock_irqsave(&smcd->lock, flags);
123 list_for_each_entry(vlan, &smcd->vlan, list) {
124 if (vlan->vlanid == vlanid) {
125 if (!refcount_dec_and_test(&vlan->refcnt))
133 goto out; /* VLAN id not in table */
136 /* Found and the last reference just gone */
137 if (smcd->ops->del_vlan_id(smcd, vlanid))
139 list_del(&vlan->list);
142 spin_unlock_irqrestore(&smcd->lock, flags);
146 int smc_ism_unregister_dmb(struct smcd_dev *smcd, struct smc_buf_desc *dmb_desc)
151 if (!dmb_desc->dma_addr)
154 memset(&dmb, 0, sizeof(dmb));
155 dmb.dmb_tok = dmb_desc->token;
156 dmb.sba_idx = dmb_desc->sba_idx;
157 dmb.cpu_addr = dmb_desc->cpu_addr;
158 dmb.dma_addr = dmb_desc->dma_addr;
159 dmb.dmb_len = dmb_desc->len;
160 rc = smcd->ops->unregister_dmb(smcd, &dmb);
161 if (!rc || rc == ISM_ERROR) {
162 dmb_desc->cpu_addr = NULL;
163 dmb_desc->dma_addr = 0;
169 int smc_ism_register_dmb(struct smc_link_group *lgr, int dmb_len,
170 struct smc_buf_desc *dmb_desc)
175 memset(&dmb, 0, sizeof(dmb));
176 dmb.dmb_len = dmb_len;
177 dmb.sba_idx = dmb_desc->sba_idx;
178 dmb.vlan_id = lgr->vlan_id;
179 dmb.rgid = lgr->peer_gid;
180 rc = lgr->smcd->ops->register_dmb(lgr->smcd, &dmb);
182 dmb_desc->sba_idx = dmb.sba_idx;
183 dmb_desc->token = dmb.dmb_tok;
184 dmb_desc->cpu_addr = dmb.cpu_addr;
185 dmb_desc->dma_addr = dmb.dma_addr;
186 dmb_desc->len = dmb.dmb_len;
191 struct smc_ism_event_work {
192 struct work_struct work;
193 struct smcd_dev *smcd;
194 struct smcd_event event;
197 #define ISM_EVENT_REQUEST 0x0001
198 #define ISM_EVENT_RESPONSE 0x0002
199 #define ISM_EVENT_REQUEST_IR 0x00000001
200 #define ISM_EVENT_CODE_SHUTDOWN 0x80
201 #define ISM_EVENT_CODE_TESTLINK 0x83
203 union smcd_sw_event_info {
206 u8 uid[SMC_LGR_ID_SIZE];
207 unsigned short vlan_id;
212 static void smcd_handle_sw_event(struct smc_ism_event_work *wrk)
214 union smcd_sw_event_info ev_info;
216 ev_info.info = wrk->event.info;
217 switch (wrk->event.code) {
218 case ISM_EVENT_CODE_SHUTDOWN: /* Peer shut down DMBs */
219 smc_smcd_terminate(wrk->smcd, wrk->event.tok, ev_info.vlan_id);
221 case ISM_EVENT_CODE_TESTLINK: /* Activity timer */
222 if (ev_info.code == ISM_EVENT_REQUEST) {
223 ev_info.code = ISM_EVENT_RESPONSE;
224 wrk->smcd->ops->signal_event(wrk->smcd,
226 ISM_EVENT_REQUEST_IR,
227 ISM_EVENT_CODE_TESTLINK,
234 int smc_ism_signal_shutdown(struct smc_link_group *lgr)
237 union smcd_sw_event_info ev_info;
239 if (lgr->peer_shutdown)
242 memcpy(ev_info.uid, lgr->id, SMC_LGR_ID_SIZE);
243 ev_info.vlan_id = lgr->vlan_id;
244 ev_info.code = ISM_EVENT_REQUEST;
245 rc = lgr->smcd->ops->signal_event(lgr->smcd, lgr->peer_gid,
246 ISM_EVENT_REQUEST_IR,
247 ISM_EVENT_CODE_SHUTDOWN,
252 /* worker for SMC-D events */
253 static void smc_ism_event_work(struct work_struct *work)
255 struct smc_ism_event_work *wrk =
256 container_of(work, struct smc_ism_event_work, work);
258 switch (wrk->event.type) {
259 case ISM_EVENT_GID: /* GID event, token is peer GID */
260 smc_smcd_terminate(wrk->smcd, wrk->event.tok, VLAN_VID_MASK);
264 case ISM_EVENT_SWR: /* Software defined event */
265 smcd_handle_sw_event(wrk);
271 static void smcd_release(struct device *dev)
273 struct smcd_dev *smcd = container_of(dev, struct smcd_dev, dev);
279 struct smcd_dev *smcd_alloc_dev(struct device *parent, const char *name,
280 const struct smcd_ops *ops, int max_dmbs)
282 struct smcd_dev *smcd;
284 smcd = kzalloc(sizeof(*smcd), GFP_KERNEL);
287 smcd->conn = kcalloc(max_dmbs, sizeof(struct smc_connection *),
294 smcd->dev.parent = parent;
295 smcd->dev.release = smcd_release;
296 device_initialize(&smcd->dev);
297 dev_set_name(&smcd->dev, name);
299 if (smc_pnetid_by_dev_port(parent, 0, smcd->pnetid))
300 smc_pnetid_by_table_smcd(smcd);
302 spin_lock_init(&smcd->lock);
303 spin_lock_init(&smcd->lgr_lock);
304 INIT_LIST_HEAD(&smcd->vlan);
305 INIT_LIST_HEAD(&smcd->lgr_list);
306 init_waitqueue_head(&smcd->lgrs_deleted);
307 smcd->event_wq = alloc_ordered_workqueue("ism_evt_wq-%s)",
308 WQ_MEM_RECLAIM, name);
309 if (!smcd->event_wq) {
316 EXPORT_SYMBOL_GPL(smcd_alloc_dev);
318 int smcd_register_dev(struct smcd_dev *smcd)
320 spin_lock(&smcd_dev_list.lock);
321 list_add_tail(&smcd->list, &smcd_dev_list.list);
322 spin_unlock(&smcd_dev_list.lock);
324 pr_warn_ratelimited("smc: adding smcd device %s with pnetid %.16s%s\n",
325 dev_name(&smcd->dev), smcd->pnetid,
326 smcd->pnetid_by_user ? " (user defined)" : "");
328 return device_add(&smcd->dev);
330 EXPORT_SYMBOL_GPL(smcd_register_dev);
332 void smcd_unregister_dev(struct smcd_dev *smcd)
334 pr_warn_ratelimited("smc: removing smcd device %s\n",
335 dev_name(&smcd->dev));
336 spin_lock(&smcd_dev_list.lock);
337 list_del_init(&smcd->list);
338 spin_unlock(&smcd_dev_list.lock);
339 smcd->going_away = 1;
340 smc_smcd_terminate_all(smcd);
341 flush_workqueue(smcd->event_wq);
342 destroy_workqueue(smcd->event_wq);
344 device_del(&smcd->dev);
346 EXPORT_SYMBOL_GPL(smcd_unregister_dev);
348 void smcd_free_dev(struct smcd_dev *smcd)
350 put_device(&smcd->dev);
352 EXPORT_SYMBOL_GPL(smcd_free_dev);
354 /* SMCD Device event handler. Called from ISM device interrupt handler.
355 * Parameters are smcd device pointer,
356 * - event->type (0 --> DMB, 1 --> GID),
357 * - event->code (event code),
358 * - event->tok (either DMB token when event type 0, or GID when event type 1)
359 * - event->time (time of day)
360 * - event->info (debug info).
363 * - Function called in IRQ context from ISM device driver event handler.
365 void smcd_handle_event(struct smcd_dev *smcd, struct smcd_event *event)
367 struct smc_ism_event_work *wrk;
369 if (smcd->going_away)
371 /* copy event to event work queue, and let it be handled there */
372 wrk = kmalloc(sizeof(*wrk), GFP_ATOMIC);
375 INIT_WORK(&wrk->work, smc_ism_event_work);
378 queue_work(smcd->event_wq, &wrk->work);
380 EXPORT_SYMBOL_GPL(smcd_handle_event);
382 /* SMCD Device interrupt handler. Called from ISM device interrupt handler.
383 * Parameters are smcd device pointer and DMB number. Find the connection and
384 * schedule the tasklet for this connection.
387 * - Function called in IRQ context from ISM device driver IRQ handler.
389 void smcd_handle_irq(struct smcd_dev *smcd, unsigned int dmbno)
391 struct smc_connection *conn = NULL;
394 spin_lock_irqsave(&smcd->lock, flags);
395 conn = smcd->conn[dmbno];
396 if (conn && !conn->killed)
397 tasklet_schedule(&conn->rx_tsklet);
398 spin_unlock_irqrestore(&smcd->lock, flags);
400 EXPORT_SYMBOL_GPL(smcd_handle_irq);