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[linux.git] / net / smc / smc_ism.c
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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/slab.h>
11#include <asm/page.h>
12
13#include "smc.h"
14#include "smc_core.h"
15#include "smc_ism.h"
1619f770 16#include "smc_pnet.h"
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17
18struct smcd_dev_list smcd_dev_list = {
19 .list = LIST_HEAD_INIT(smcd_dev_list.list),
20 .lock = __SPIN_LOCK_UNLOCKED(smcd_dev_list.lock)
21};
22
23/* Test if an ISM communication is possible. */
24int smc_ism_cantalk(u64 peer_gid, unsigned short vlan_id, struct smcd_dev *smcd)
25{
26 return smcd->ops->query_remote_gid(smcd, peer_gid, vlan_id ? 1 : 0,
27 vlan_id);
28}
29
30int smc_ism_write(struct smcd_dev *smcd, const struct smc_ism_position *pos,
31 void *data, size_t len)
32{
33 int rc;
34
35 rc = smcd->ops->move_data(smcd, pos->token, pos->index, pos->signal,
36 pos->offset, data, len);
37
38 return rc < 0 ? rc : 0;
39}
40
41/* Set a connection using this DMBE. */
42void smc_ism_set_conn(struct smc_connection *conn)
43{
44 unsigned long flags;
45
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);
49}
50
51/* Unset a connection using this DMBE. */
52void smc_ism_unset_conn(struct smc_connection *conn)
53{
54 unsigned long flags;
55
56 if (!conn->rmb_desc)
57 return;
58
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);
62}
63
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
66 * registered.
67 */
68int smc_ism_get_vlan(struct smcd_dev *smcd, unsigned short vlanid)
69{
70 struct smc_ism_vlanid *new_vlan, *vlan;
71 unsigned long flags;
72 int rc = 0;
73
74 if (!vlanid) /* No valid vlan id */
75 return -EINVAL;
76
77 /* create new vlan entry, in case we need it */
78 new_vlan = kzalloc(sizeof(*new_vlan), GFP_KERNEL);
79 if (!new_vlan)
80 return -ENOMEM;
81 new_vlan->vlanid = vlanid;
82 refcount_set(&new_vlan->refcnt, 1);
83
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);
89 kfree(new_vlan);
90 goto out;
91 }
92 }
93
94 /* no existing entry found.
95 * add new entry to device; might fail, e.g., if HW limit reached
96 */
97 if (smcd->ops->add_vlan_id(smcd, vlanid)) {
98 kfree(new_vlan);
99 rc = -EIO;
100 goto out;
101 }
102 list_add_tail(&new_vlan->list, &smcd->vlan);
103out:
104 spin_unlock_irqrestore(&smcd->lock, flags);
105 return rc;
106}
107
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
110 * unregistered.
111 */
112int smc_ism_put_vlan(struct smcd_dev *smcd, unsigned short vlanid)
113{
114 struct smc_ism_vlanid *vlan;
115 unsigned long flags;
116 bool found = false;
117 int rc = 0;
118
119 if (!vlanid) /* No valid vlan id */
120 return -EINVAL;
121
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))
126 goto out;
127 found = true;
128 break;
129 }
130 }
131 if (!found) {
132 rc = -ENOENT;
133 goto out; /* VLAN id not in table */
134 }
135
136 /* Found and the last reference just gone */
137 if (smcd->ops->del_vlan_id(smcd, vlanid))
138 rc = -EIO;
139 list_del(&vlan->list);
140 kfree(vlan);
141out:
142 spin_unlock_irqrestore(&smcd->lock, flags);
143 return rc;
144}
145
146int smc_ism_unregister_dmb(struct smcd_dev *smcd, struct smc_buf_desc *dmb_desc)
147{
148 struct smcd_dmb dmb;
149
150 memset(&dmb, 0, sizeof(dmb));
151 dmb.dmb_tok = dmb_desc->token;
152 dmb.sba_idx = dmb_desc->sba_idx;
153 dmb.cpu_addr = dmb_desc->cpu_addr;
154 dmb.dma_addr = dmb_desc->dma_addr;
155 dmb.dmb_len = dmb_desc->len;
156 return smcd->ops->unregister_dmb(smcd, &dmb);
157}
158
159int smc_ism_register_dmb(struct smc_link_group *lgr, int dmb_len,
160 struct smc_buf_desc *dmb_desc)
161{
162 struct smcd_dmb dmb;
163 int rc;
164
165 memset(&dmb, 0, sizeof(dmb));
166 dmb.dmb_len = dmb_len;
167 dmb.sba_idx = dmb_desc->sba_idx;
168 dmb.vlan_id = lgr->vlan_id;
169 dmb.rgid = lgr->peer_gid;
170 rc = lgr->smcd->ops->register_dmb(lgr->smcd, &dmb);
171 if (!rc) {
172 dmb_desc->sba_idx = dmb.sba_idx;
173 dmb_desc->token = dmb.dmb_tok;
174 dmb_desc->cpu_addr = dmb.cpu_addr;
175 dmb_desc->dma_addr = dmb.dma_addr;
176 dmb_desc->len = dmb.dmb_len;
177 }
178 return rc;
179}
180
181struct smc_ism_event_work {
182 struct work_struct work;
183 struct smcd_dev *smcd;
184 struct smcd_event event;
185};
186
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187#define ISM_EVENT_REQUEST 0x0001
188#define ISM_EVENT_RESPONSE 0x0002
189#define ISM_EVENT_REQUEST_IR 0x00000001
190#define ISM_EVENT_CODE_TESTLINK 0x83
191
192static void smcd_handle_sw_event(struct smc_ism_event_work *wrk)
193{
194 union {
195 u64 info;
196 struct {
197 u32 uid;
198 unsigned short vlanid;
199 u16 code;
200 };
201 } ev_info;
202
203 switch (wrk->event.code) {
204 case ISM_EVENT_CODE_TESTLINK: /* Activity timer */
205 ev_info.info = wrk->event.info;
206 if (ev_info.code == ISM_EVENT_REQUEST) {
207 ev_info.code = ISM_EVENT_RESPONSE;
208 wrk->smcd->ops->signal_event(wrk->smcd,
209 wrk->event.tok,
210 ISM_EVENT_REQUEST_IR,
211 ISM_EVENT_CODE_TESTLINK,
212 ev_info.info);
213 }
214 break;
215 }
216}
217
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218/* worker for SMC-D events */
219static void smc_ism_event_work(struct work_struct *work)
220{
221 struct smc_ism_event_work *wrk =
222 container_of(work, struct smc_ism_event_work, work);
223
224 switch (wrk->event.type) {
225 case ISM_EVENT_GID: /* GID event, token is peer GID */
226 smc_smcd_terminate(wrk->smcd, wrk->event.tok);
227 break;
228 case ISM_EVENT_DMB:
229 break;
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230 case ISM_EVENT_SWR: /* Software defined event */
231 smcd_handle_sw_event(wrk);
232 break;
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233 }
234 kfree(wrk);
235}
236
237static void smcd_release(struct device *dev)
238{
239 struct smcd_dev *smcd = container_of(dev, struct smcd_dev, dev);
240
241 kfree(smcd->conn);
242 kfree(smcd);
243}
244
245struct smcd_dev *smcd_alloc_dev(struct device *parent, const char *name,
246 const struct smcd_ops *ops, int max_dmbs)
247{
248 struct smcd_dev *smcd;
249
250 smcd = kzalloc(sizeof(*smcd), GFP_KERNEL);
251 if (!smcd)
252 return NULL;
253 smcd->conn = kcalloc(max_dmbs, sizeof(struct smc_connection *),
254 GFP_KERNEL);
255 if (!smcd->conn) {
256 kfree(smcd);
257 return NULL;
258 }
259
260 smcd->dev.parent = parent;
261 smcd->dev.release = smcd_release;
262 device_initialize(&smcd->dev);
263 dev_set_name(&smcd->dev, name);
264 smcd->ops = ops;
1619f770 265 smc_pnetid_by_dev_port(parent, 0, smcd->pnetid);
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266
267 spin_lock_init(&smcd->lock);
268 INIT_LIST_HEAD(&smcd->vlan);
269 smcd->event_wq = alloc_ordered_workqueue("ism_evt_wq-%s)",
270 WQ_MEM_RECLAIM, name);
271 return smcd;
272}
273EXPORT_SYMBOL_GPL(smcd_alloc_dev);
274
275int smcd_register_dev(struct smcd_dev *smcd)
276{
277 spin_lock(&smcd_dev_list.lock);
278 list_add_tail(&smcd->list, &smcd_dev_list.list);
279 spin_unlock(&smcd_dev_list.lock);
280
281 return device_add(&smcd->dev);
282}
283EXPORT_SYMBOL_GPL(smcd_register_dev);
284
285void smcd_unregister_dev(struct smcd_dev *smcd)
286{
287 spin_lock(&smcd_dev_list.lock);
288 list_del(&smcd->list);
289 spin_unlock(&smcd_dev_list.lock);
290 flush_workqueue(smcd->event_wq);
291 destroy_workqueue(smcd->event_wq);
292 smc_smcd_terminate(smcd, 0);
293
294 device_del(&smcd->dev);
295}
296EXPORT_SYMBOL_GPL(smcd_unregister_dev);
297
298void smcd_free_dev(struct smcd_dev *smcd)
299{
300 put_device(&smcd->dev);
301}
302EXPORT_SYMBOL_GPL(smcd_free_dev);
303
304/* SMCD Device event handler. Called from ISM device interrupt handler.
305 * Parameters are smcd device pointer,
306 * - event->type (0 --> DMB, 1 --> GID),
307 * - event->code (event code),
308 * - event->tok (either DMB token when event type 0, or GID when event type 1)
309 * - event->time (time of day)
310 * - event->info (debug info).
311 *
312 * Context:
313 * - Function called in IRQ context from ISM device driver event handler.
314 */
315void smcd_handle_event(struct smcd_dev *smcd, struct smcd_event *event)
316{
317 struct smc_ism_event_work *wrk;
318
319 /* copy event to event work queue, and let it be handled there */
320 wrk = kmalloc(sizeof(*wrk), GFP_ATOMIC);
321 if (!wrk)
322 return;
323 INIT_WORK(&wrk->work, smc_ism_event_work);
324 wrk->smcd = smcd;
325 wrk->event = *event;
326 queue_work(smcd->event_wq, &wrk->work);
327}
328EXPORT_SYMBOL_GPL(smcd_handle_event);
329
330/* SMCD Device interrupt handler. Called from ISM device interrupt handler.
331 * Parameters are smcd device pointer and DMB number. Find the connection and
332 * schedule the tasklet for this connection.
333 *
334 * Context:
335 * - Function called in IRQ context from ISM device driver IRQ handler.
336 */
337void smcd_handle_irq(struct smcd_dev *smcd, unsigned int dmbno)
338{
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HW
339 struct smc_connection *conn = NULL;
340 unsigned long flags;
341
342 spin_lock_irqsave(&smcd->lock, flags);
343 conn = smcd->conn[dmbno];
344 if (conn)
345 tasklet_schedule(&conn->rx_tsklet);
346 spin_unlock_irqrestore(&smcd->lock, flags);
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347}
348EXPORT_SYMBOL_GPL(smcd_handle_irq);
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