summaryrefslogtreecommitdiffstats
path: root/net/smc/smc_ism.c
blob: ee7340898cb4d534b3f9ccd6607ab05850796767 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
// SPDX-License-Identifier: GPL-2.0
/* Shared Memory Communications Direct over ISM devices (SMC-D)
 *
 * Functions for ISM device.
 *
 * Copyright IBM Corp. 2018
 */

#include <linux/spinlock.h>
#include <linux/slab.h>
#include <asm/page.h>

#include "smc.h"
#include "smc_core.h"
#include "smc_ism.h"
#include "smc_pnet.h"

struct smcd_dev_list smcd_dev_list = {
	.list = LIST_HEAD_INIT(smcd_dev_list.list),
	.lock = __SPIN_LOCK_UNLOCKED(smcd_dev_list.lock)
};

/* Test if an ISM communication is possible. */
int smc_ism_cantalk(u64 peer_gid, unsigned short vlan_id, struct smcd_dev *smcd)
{
	return smcd->ops->query_remote_gid(smcd, peer_gid, vlan_id ? 1 : 0,
					   vlan_id);
}

int smc_ism_write(struct smcd_dev *smcd, const struct smc_ism_position *pos,
		  void *data, size_t len)
{
	int rc;

	rc = smcd->ops->move_data(smcd, pos->token, pos->index, pos->signal,
				  pos->offset, data, len);

	return rc < 0 ? rc : 0;
}

/* Set a connection using this DMBE. */
void smc_ism_set_conn(struct smc_connection *conn)
{
	unsigned long flags;

	spin_lock_irqsave(&conn->lgr->smcd->lock, flags);
	conn->lgr->smcd->conn[conn->rmb_desc->sba_idx] = conn;
	spin_unlock_irqrestore(&conn->lgr->smcd->lock, flags);
}

/* Unset a connection using this DMBE. */
void smc_ism_unset_conn(struct smc_connection *conn)
{
	unsigned long flags;

	if (!conn->rmb_desc)
		return;

	spin_lock_irqsave(&conn->lgr->smcd->lock, flags);
	conn->lgr->smcd->conn[conn->rmb_desc->sba_idx] = NULL;
	spin_unlock_irqrestore(&conn->lgr->smcd->lock, flags);
}

/* Register a VLAN identifier with the ISM device. Use a reference count
 * and add a VLAN identifier only when the first DMB using this VLAN is
 * registered.
 */
int smc_ism_get_vlan(struct smcd_dev *smcd, unsigned short vlanid)
{
	struct smc_ism_vlanid *new_vlan, *vlan;
	unsigned long flags;
	int rc = 0;

	if (!vlanid)			/* No valid vlan id */
		return -EINVAL;

	/* create new vlan entry, in case we need it */
	new_vlan = kzalloc(sizeof(*new_vlan), GFP_KERNEL);
	if (!new_vlan)
		return -ENOMEM;
	new_vlan->vlanid = vlanid;
	refcount_set(&new_vlan->refcnt, 1);

	/* if there is an existing entry, increase count and return */
	spin_lock_irqsave(&smcd->lock, flags);
	list_for_each_entry(vlan, &smcd->vlan, list) {
		if (vlan->vlanid == vlanid) {
			refcount_inc(&vlan->refcnt);
			kfree(new_vlan);
			goto out;
		}
	}

	/* no existing entry found.
	 * add new entry to device; might fail, e.g., if HW limit reached
	 */
	if (smcd->ops->add_vlan_id(smcd, vlanid)) {
		kfree(new_vlan);
		rc = -EIO;
		goto out;
	}
	list_add_tail(&new_vlan->list, &smcd->vlan);
out:
	spin_unlock_irqrestore(&smcd->lock, flags);
	return rc;
}

/* Unregister a VLAN identifier with the ISM device. Use a reference count
 * and remove a VLAN identifier only when the last DMB using this VLAN is
 * unregistered.
 */
int smc_ism_put_vlan(struct smcd_dev *smcd, unsigned short vlanid)
{
	struct smc_ism_vlanid *vlan;
	unsigned long flags;
	bool found = false;
	int rc = 0;

	if (!vlanid)			/* No valid vlan id */
		return -EINVAL;

	spin_lock_irqsave(&smcd->lock, flags);
	list_for_each_entry(vlan, &smcd->vlan, list) {
		if (vlan->vlanid == vlanid) {
			if (!refcount_dec_and_test(&vlan->refcnt))
				goto out;
			found = true;
			break;
		}
	}
	if (!found) {
		rc = -ENOENT;
		goto out;		/* VLAN id not in table */
	}

	/* Found and the last reference just gone */
	if (smcd->ops->del_vlan_id(smcd, vlanid))
		rc = -EIO;
	list_del(&vlan->list);
	kfree(vlan);
out:
	spin_unlock_irqrestore(&smcd->lock, flags);
	return rc;
}

int smc_ism_unregister_dmb(struct smcd_dev *smcd, struct smc_buf_desc *dmb_desc)
{
	struct smcd_dmb dmb;

	memset(&dmb, 0, sizeof(dmb));
	dmb.dmb_tok = dmb_desc->token;
	dmb.sba_idx = dmb_desc->sba_idx;
	dmb.cpu_addr = dmb_desc->cpu_addr;
	dmb.dma_addr = dmb_desc->dma_addr;
	dmb.dmb_len = dmb_desc->len;
	return smcd->ops->unregister_dmb(smcd, &dmb);
}

int smc_ism_register_dmb(struct smc_link_group *lgr, int dmb_len,
			 struct smc_buf_desc *dmb_desc)
{
	struct smcd_dmb dmb;
	int rc;

	memset(&dmb, 0, sizeof(dmb));
	dmb.dmb_len = dmb_len;
	dmb.sba_idx = dmb_desc->sba_idx;
	dmb.vlan_id = lgr->vlan_id;
	dmb.rgid = lgr->peer_gid;
	rc = lgr->smcd->ops->register_dmb(lgr->smcd, &dmb);
	if (!rc) {
		dmb_desc->sba_idx = dmb.sba_idx;
		dmb_desc->token = dmb.dmb_tok;
		dmb_desc->cpu_addr = dmb.cpu_addr;
		dmb_desc->dma_addr = dmb.dma_addr;
		dmb_desc->len = dmb.dmb_len;
	}
	return rc;
}

struct smc_ism_event_work {
	struct work_struct work;
	struct smcd_dev *smcd;
	struct smcd_event event;
};

#define ISM_EVENT_REQUEST		0x0001
#define ISM_EVENT_RESPONSE		0x0002
#define ISM_EVENT_REQUEST_IR		0x00000001
#define ISM_EVENT_CODE_SHUTDOWN		0x80
#define ISM_EVENT_CODE_TESTLINK		0x83

union smcd_sw_event_info {
	u64	info;
	struct {
		u8		uid[SMC_LGR_ID_SIZE];
		unsigned short	vlan_id;
		u16		code;
	};
};

static void smcd_handle_sw_event(struct smc_ism_event_work *wrk)
{
	union smcd_sw_event_info ev_info;

	ev_info.info = wrk->event.info;
	switch (wrk->event.code) {
	case ISM_EVENT_CODE_SHUTDOWN:	/* Peer shut down DMBs */
		smc_smcd_terminate(wrk->smcd, wrk->event.tok, ev_info.vlan_id);
		break;
	case ISM_EVENT_CODE_TESTLINK:	/* Activity timer */
		if (ev_info.code == ISM_EVENT_REQUEST) {
			ev_info.code = ISM_EVENT_RESPONSE;
			wrk->smcd->ops->signal_event(wrk->smcd,
						     wrk->event.tok,
						     ISM_EVENT_REQUEST_IR,
						     ISM_EVENT_CODE_TESTLINK,
						     ev_info.info);
			}
		break;
	}
}

int smc_ism_signal_shutdown(struct smc_link_group *lgr)
{
	int rc;
	union smcd_sw_event_info ev_info;

	memcpy(ev_info.uid, lgr->id, SMC_LGR_ID_SIZE);
	ev_info.vlan_id = lgr->vlan_id;
	ev_info.code = ISM_EVENT_REQUEST;
	rc = lgr->smcd->ops->signal_event(lgr->smcd, lgr->peer_gid,
					  ISM_EVENT_REQUEST_IR,
					  ISM_EVENT_CODE_SHUTDOWN,
					  ev_info.info);
	return rc;
}

/* worker for SMC-D events */
static void smc_ism_event_work(struct work_struct *work)
{
	struct smc_ism_event_work *wrk =
		container_of(work, struct smc_ism_event_work, work);

	switch (wrk->event.type) {
	case ISM_EVENT_GID:	/* GID event, token is peer GID */
		smc_smcd_terminate(wrk->smcd, wrk->event.tok, VLAN_VID_MASK);
		break;
	case ISM_EVENT_DMB:
		break;
	case ISM_EVENT_SWR:	/* Software defined event */
		smcd_handle_sw_event(wrk);
		break;
	}
	kfree(wrk);
}

static void smcd_release(struct device *dev)
{
	struct smcd_dev *smcd = container_of(dev, struct smcd_dev, dev);

	kfree(smcd->conn);
	kfree(smcd);
}

struct smcd_dev *smcd_alloc_dev(struct device *parent, const char *name,
				const struct smcd_ops *ops, int max_dmbs)
{
	struct smcd_dev *smcd;

	smcd = kzalloc(sizeof(*smcd), GFP_KERNEL);
	if (!smcd)
		return NULL;
	smcd->conn = kcalloc(max_dmbs, sizeof(struct smc_connection *),
			     GFP_KERNEL);
	if (!smcd->conn) {
		kfree(smcd);
		return NULL;
	}

	smcd->dev.parent = parent;
	smcd->dev.release = smcd_release;
	device_initialize(&smcd->dev);
	dev_set_name(&smcd->dev, name);
	smcd->ops = ops;
	smc_pnetid_by_dev_port(parent, 0, smcd->pnetid);

	spin_lock_init(&smcd->lock);
	spin_lock_init(&smcd->lgr_lock);
	INIT_LIST_HEAD(&smcd->vlan);
	INIT_LIST_HEAD(&smcd->lgr_list);
	smcd->event_wq = alloc_ordered_workqueue("ism_evt_wq-%s)",
						 WQ_MEM_RECLAIM, name);
	if (!smcd->event_wq) {
		kfree(smcd->conn);
		kfree(smcd);
		return NULL;
	}
	return smcd;
}
EXPORT_SYMBOL_GPL(smcd_alloc_dev);

int smcd_register_dev(struct smcd_dev *smcd)
{
	spin_lock(&smcd_dev_list.lock);
	list_add_tail(&smcd->list, &smcd_dev_list.list);
	spin_unlock(&smcd_dev_list.lock);

	return device_add(&smcd->dev);
}
EXPORT_SYMBOL_GPL(smcd_register_dev);

void smcd_unregister_dev(struct smcd_dev *smcd)
{
	spin_lock(&smcd_dev_list.lock);
	list_del(&smcd->list);
	spin_unlock(&smcd_dev_list.lock);
	smcd->going_away = 1;
	flush_workqueue(smcd->event_wq);
	destroy_workqueue(smcd->event_wq);
	smc_smcd_terminate(smcd, 0, VLAN_VID_MASK);

	device_del(&smcd->dev);
}
EXPORT_SYMBOL_GPL(smcd_unregister_dev);

void smcd_free_dev(struct smcd_dev *smcd)
{
	put_device(&smcd->dev);
}
EXPORT_SYMBOL_GPL(smcd_free_dev);

/* SMCD Device event handler. Called from ISM device interrupt handler.
 * Parameters are smcd device pointer,
 * - event->type (0 --> DMB, 1 --> GID),
 * - event->code (event code),
 * - event->tok (either DMB token when event type 0, or GID when event type 1)
 * - event->time (time of day)
 * - event->info (debug info).
 *
 * Context:
 * - Function called in IRQ context from ISM device driver event handler.
 */
void smcd_handle_event(struct smcd_dev *smcd, struct smcd_event *event)
{
	struct smc_ism_event_work *wrk;

	if (smcd->going_away)
		return;
	/* copy event to event work queue, and let it be handled there */
	wrk = kmalloc(sizeof(*wrk), GFP_ATOMIC);
	if (!wrk)
		return;
	INIT_WORK(&wrk->work, smc_ism_event_work);
	wrk->smcd = smcd;
	wrk->event = *event;
	queue_work(smcd->event_wq, &wrk->work);
}
EXPORT_SYMBOL_GPL(smcd_handle_event);

/* SMCD Device interrupt handler. Called from ISM device interrupt handler.
 * Parameters are smcd device pointer and DMB number. Find the connection and
 * schedule the tasklet for this connection.
 *
 * Context:
 * - Function called in IRQ context from ISM device driver IRQ handler.
 */
void smcd_handle_irq(struct smcd_dev *smcd, unsigned int dmbno)
{
	struct smc_connection *conn = NULL;
	unsigned long flags;

	spin_lock_irqsave(&smcd->lock, flags);
	conn = smcd->conn[dmbno];
	if (conn)
		tasklet_schedule(&conn->rx_tsklet);
	spin_unlock_irqrestore(&smcd->lock, flags);
}
EXPORT_SYMBOL_GPL(smcd_handle_irq);