1// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
2/*
3 * Copyright(c) 2016 - 2018 Intel Corporation.
4 */
5
6#include <linux/slab.h>
7#include <linux/vmalloc.h>
8#include "cq.h"
9#include "vt.h"
10#include "trace.h"
11
12static struct workqueue_struct *comp_vector_wq;
13
14/**
15 * rvt_cq_enter - add a new entry to the completion queue
16 * @cq: completion queue
17 * @entry: work completion entry to add
18 * @solicited: true if @entry is solicited
19 *
20 * This may be called with qp->s_lock held.
21 *
22 * Return: return true on success, else return
23 * false if cq is full.
24 */
25bool rvt_cq_enter(struct rvt_cq *cq, struct ib_wc *entry, bool solicited)
26{
27	struct ib_uverbs_wc *uqueue = NULL;
28	struct ib_wc *kqueue = NULL;
29	struct rvt_cq_wc *u_wc = NULL;
30	struct rvt_k_cq_wc *k_wc = NULL;
31	unsigned long flags;
32	u32 head;
33	u32 next;
34	u32 tail;
35
36	spin_lock_irqsave(&cq->lock, flags);
37
38	if (cq->ip) {
39		u_wc = cq->queue;
40		uqueue = &u_wc->uqueue[0];
41		head = RDMA_READ_UAPI_ATOMIC(u_wc->head);
42		tail = RDMA_READ_UAPI_ATOMIC(u_wc->tail);
43	} else {
44		k_wc = cq->kqueue;
45		kqueue = &k_wc->kqueue[0];
46		head = k_wc->head;
47		tail = k_wc->tail;
48	}
49
50	/*
51	 * Note that the head pointer might be writable by
52	 * user processes.Take care to verify it is a sane value.
53	 */
54	if (head >= (unsigned)cq->ibcq.cqe) {
55		head = cq->ibcq.cqe;
56		next = 0;
57	} else {
58		next = head + 1;
59	}
60
61	if (unlikely(next == tail || cq->cq_full)) {
62		struct rvt_dev_info *rdi = cq->rdi;
63
64		if (!cq->cq_full)
65			rvt_pr_err_ratelimited(rdi, "CQ is full!\n");
66		cq->cq_full = true;
67		spin_unlock_irqrestore(&cq->lock, flags);
68		if (cq->ibcq.event_handler) {
69			struct ib_event ev;
70
71			ev.device = cq->ibcq.device;
72			ev.element.cq = &cq->ibcq;
73			ev.event = IB_EVENT_CQ_ERR;
74			cq->ibcq.event_handler(&ev, cq->ibcq.cq_context);
75		}
76		return false;
77	}
78	trace_rvt_cq_enter(cq, entry, head);
79	if (uqueue) {
80		uqueue[head].wr_id = entry->wr_id;
81		uqueue[head].status = entry->status;
82		uqueue[head].opcode = entry->opcode;
83		uqueue[head].vendor_err = entry->vendor_err;
84		uqueue[head].byte_len = entry->byte_len;
85		uqueue[head].ex.imm_data = entry->ex.imm_data;
86		uqueue[head].qp_num = entry->qp->qp_num;
87		uqueue[head].src_qp = entry->src_qp;
88		uqueue[head].wc_flags = entry->wc_flags;
89		uqueue[head].pkey_index = entry->pkey_index;
90		uqueue[head].slid = ib_lid_cpu16(entry->slid);
91		uqueue[head].sl = entry->sl;
92		uqueue[head].dlid_path_bits = entry->dlid_path_bits;
93		uqueue[head].port_num = entry->port_num;
94		/* Make sure entry is written before the head index. */
95		RDMA_WRITE_UAPI_ATOMIC(u_wc->head, next);
96	} else {
97		kqueue[head] = *entry;
98		k_wc->head = next;
99	}
100
101	if (cq->notify == IB_CQ_NEXT_COMP ||
102	    (cq->notify == IB_CQ_SOLICITED &&
103	     (solicited || entry->status != IB_WC_SUCCESS))) {
104		/*
105		 * This will cause send_complete() to be called in
106		 * another thread.
107		 */
108		cq->notify = RVT_CQ_NONE;
109		cq->triggered++;
110		queue_work_on(cq->comp_vector_cpu, comp_vector_wq,
111			      &cq->comptask);
112	}
113
114	spin_unlock_irqrestore(&cq->lock, flags);
115	return true;
116}
117EXPORT_SYMBOL(rvt_cq_enter);
118
119static void send_complete(struct work_struct *work)
120{
121	struct rvt_cq *cq = container_of(work, struct rvt_cq, comptask);
122
123	/*
124	 * The completion handler will most likely rearm the notification
125	 * and poll for all pending entries.  If a new completion entry
126	 * is added while we are in this routine, queue_work()
127	 * won't call us again until we return so we check triggered to
128	 * see if we need to call the handler again.
129	 */
130	for (;;) {
131		u8 triggered = cq->triggered;
132
133		/*
134		 * IPoIB connected mode assumes the callback is from a
135		 * soft IRQ. We simulate this by blocking "bottom halves".
136		 * See the implementation for ipoib_cm_handle_tx_wc(),
137		 * netif_tx_lock_bh() and netif_tx_lock().
138		 */
139		local_bh_disable();
140		cq->ibcq.comp_handler(&cq->ibcq, cq->ibcq.cq_context);
141		local_bh_enable();
142
143		if (cq->triggered == triggered)
144			return;
145	}
146}
147
148/**
149 * rvt_create_cq - create a completion queue
150 * @ibcq: Allocated CQ
151 * @attr: creation attributes
152 * @udata: user data for libibverbs.so
153 *
154 * Called by ib_create_cq() in the generic verbs code.
155 *
156 * Return: 0 on success
157 */
158int rvt_create_cq(struct ib_cq *ibcq, const struct ib_cq_init_attr *attr,
159		  struct ib_udata *udata)
160{
161	struct ib_device *ibdev = ibcq->device;
162	struct rvt_dev_info *rdi = ib_to_rvt(ibdev);
163	struct rvt_cq *cq = ibcq_to_rvtcq(ibcq);
164	struct rvt_cq_wc *u_wc = NULL;
165	struct rvt_k_cq_wc *k_wc = NULL;
166	u32 sz;
167	unsigned int entries = attr->cqe;
168	int comp_vector = attr->comp_vector;
169	int err;
170
171	if (attr->flags)
172		return -EOPNOTSUPP;
173
174	if (entries < 1 || entries > rdi->dparms.props.max_cqe)
175		return -EINVAL;
176
177	if (comp_vector < 0)
178		comp_vector = 0;
179
180	comp_vector = comp_vector % rdi->ibdev.num_comp_vectors;
181
182	/*
183	 * Allocate the completion queue entries and head/tail pointers.
184	 * This is allocated separately so that it can be resized and
185	 * also mapped into user space.
186	 * We need to use vmalloc() in order to support mmap and large
187	 * numbers of entries.
188	 */
189	if (udata && udata->outlen >= sizeof(__u64)) {
190		sz = sizeof(struct ib_uverbs_wc) * (entries + 1);
191		sz += sizeof(*u_wc);
192		u_wc = vmalloc_user(sz);
193		if (!u_wc)
194			return -ENOMEM;
195	} else {
196		sz = sizeof(struct ib_wc) * (entries + 1);
197		sz += sizeof(*k_wc);
198		k_wc = vzalloc_node(sz, rdi->dparms.node);
199		if (!k_wc)
200			return -ENOMEM;
201	}
202
203	/*
204	 * Return the address of the WC as the offset to mmap.
205	 * See rvt_mmap() for details.
206	 */
207	if (udata && udata->outlen >= sizeof(__u64)) {
208		cq->ip = rvt_create_mmap_info(rdi, sz, udata, u_wc);
209		if (IS_ERR(cq->ip)) {
210			err = PTR_ERR(cq->ip);
211			goto bail_wc;
212		}
213
214		err = ib_copy_to_udata(udata, &cq->ip->offset,
215				       sizeof(cq->ip->offset));
216		if (err)
217			goto bail_ip;
218	}
219
220	spin_lock_irq(&rdi->n_cqs_lock);
221	if (rdi->n_cqs_allocated == rdi->dparms.props.max_cq) {
222		spin_unlock_irq(&rdi->n_cqs_lock);
223		err = -ENOMEM;
224		goto bail_ip;
225	}
226
227	rdi->n_cqs_allocated++;
228	spin_unlock_irq(&rdi->n_cqs_lock);
229
230	if (cq->ip) {
231		spin_lock_irq(&rdi->pending_lock);
232		list_add(&cq->ip->pending_mmaps, &rdi->pending_mmaps);
233		spin_unlock_irq(&rdi->pending_lock);
234	}
235
236	/*
237	 * ib_create_cq() will initialize cq->ibcq except for cq->ibcq.cqe.
238	 * The number of entries should be >= the number requested or return
239	 * an error.
240	 */
241	cq->rdi = rdi;
242	if (rdi->driver_f.comp_vect_cpu_lookup)
243		cq->comp_vector_cpu =
244			rdi->driver_f.comp_vect_cpu_lookup(rdi, comp_vector);
245	else
246		cq->comp_vector_cpu =
247			cpumask_first(cpumask_of_node(rdi->dparms.node));
248
249	cq->ibcq.cqe = entries;
250	cq->notify = RVT_CQ_NONE;
251	spin_lock_init(&cq->lock);
252	INIT_WORK(&cq->comptask, send_complete);
253	if (u_wc)
254		cq->queue = u_wc;
255	else
256		cq->kqueue = k_wc;
257
258	trace_rvt_create_cq(cq, attr);
259	return 0;
260
261bail_ip:
262	kfree(cq->ip);
263bail_wc:
264	vfree(u_wc);
265	vfree(k_wc);
266	return err;
267}
268
269/**
270 * rvt_destroy_cq - destroy a completion queue
271 * @ibcq: the completion queue to destroy.
272 * @udata: user data or NULL for kernel object
273 *
274 * Called by ib_destroy_cq() in the generic verbs code.
275 */
276int rvt_destroy_cq(struct ib_cq *ibcq, struct ib_udata *udata)
277{
278	struct rvt_cq *cq = ibcq_to_rvtcq(ibcq);
279	struct rvt_dev_info *rdi = cq->rdi;
280
281	flush_work(&cq->comptask);
282	spin_lock_irq(&rdi->n_cqs_lock);
283	rdi->n_cqs_allocated--;
284	spin_unlock_irq(&rdi->n_cqs_lock);
285	if (cq->ip)
286		kref_put(&cq->ip->ref, rvt_release_mmap_info);
287	else
288		vfree(cq->kqueue);
289	return 0;
290}
291
292/**
293 * rvt_req_notify_cq - change the notification type for a completion queue
294 * @ibcq: the completion queue
295 * @notify_flags: the type of notification to request
296 *
297 * This may be called from interrupt context.  Also called by
298 * ib_req_notify_cq() in the generic verbs code.
299 *
300 * Return: 0 for success.
301 */
302int rvt_req_notify_cq(struct ib_cq *ibcq, enum ib_cq_notify_flags notify_flags)
303{
304	struct rvt_cq *cq = ibcq_to_rvtcq(ibcq);
305	unsigned long flags;
306	int ret = 0;
307
308	spin_lock_irqsave(&cq->lock, flags);
309	/*
310	 * Don't change IB_CQ_NEXT_COMP to IB_CQ_SOLICITED but allow
311	 * any other transitions (see C11-31 and C11-32 in ch. 11.4.2.2).
312	 */
313	if (cq->notify != IB_CQ_NEXT_COMP)
314		cq->notify = notify_flags & IB_CQ_SOLICITED_MASK;
315
316	if (notify_flags & IB_CQ_REPORT_MISSED_EVENTS) {
317		if (cq->queue) {
318			if (RDMA_READ_UAPI_ATOMIC(cq->queue->head) !=
319				RDMA_READ_UAPI_ATOMIC(cq->queue->tail))
320				ret = 1;
321		} else {
322			if (cq->kqueue->head != cq->kqueue->tail)
323				ret = 1;
324		}
325	}
326
327	spin_unlock_irqrestore(&cq->lock, flags);
328
329	return ret;
330}
331
332/*
333 * rvt_resize_cq - change the size of the CQ
334 * @ibcq: the completion queue
335 *
336 * Return: 0 for success.
337 */
338int rvt_resize_cq(struct ib_cq *ibcq, int cqe, struct ib_udata *udata)
339{
340	struct rvt_cq *cq = ibcq_to_rvtcq(ibcq);
341	u32 head, tail, n;
342	int ret;
343	u32 sz;
344	struct rvt_dev_info *rdi = cq->rdi;
345	struct rvt_cq_wc *u_wc = NULL;
346	struct rvt_cq_wc *old_u_wc = NULL;
347	struct rvt_k_cq_wc *k_wc = NULL;
348	struct rvt_k_cq_wc *old_k_wc = NULL;
349
350	if (cqe < 1 || cqe > rdi->dparms.props.max_cqe)
351		return -EINVAL;
352
353	/*
354	 * Need to use vmalloc() if we want to support large #s of entries.
355	 */
356	if (udata && udata->outlen >= sizeof(__u64)) {
357		sz = sizeof(struct ib_uverbs_wc) * (cqe + 1);
358		sz += sizeof(*u_wc);
359		u_wc = vmalloc_user(sz);
360		if (!u_wc)
361			return -ENOMEM;
362	} else {
363		sz = sizeof(struct ib_wc) * (cqe + 1);
364		sz += sizeof(*k_wc);
365		k_wc = vzalloc_node(sz, rdi->dparms.node);
366		if (!k_wc)
367			return -ENOMEM;
368	}
369	/* Check that we can write the offset to mmap. */
370	if (udata && udata->outlen >= sizeof(__u64)) {
371		__u64 offset = 0;
372
373		ret = ib_copy_to_udata(udata, &offset, sizeof(offset));
374		if (ret)
375			goto bail_free;
376	}
377
378	spin_lock_irq(&cq->lock);
379	/*
380	 * Make sure head and tail are sane since they
381	 * might be user writable.
382	 */
383	if (u_wc) {
384		old_u_wc = cq->queue;
385		head = RDMA_READ_UAPI_ATOMIC(old_u_wc->head);
386		tail = RDMA_READ_UAPI_ATOMIC(old_u_wc->tail);
387	} else {
388		old_k_wc = cq->kqueue;
389		head = old_k_wc->head;
390		tail = old_k_wc->tail;
391	}
392
393	if (head > (u32)cq->ibcq.cqe)
394		head = (u32)cq->ibcq.cqe;
395	if (tail > (u32)cq->ibcq.cqe)
396		tail = (u32)cq->ibcq.cqe;
397	if (head < tail)
398		n = cq->ibcq.cqe + 1 + head - tail;
399	else
400		n = head - tail;
401	if (unlikely((u32)cqe < n)) {
402		ret = -EINVAL;
403		goto bail_unlock;
404	}
405	for (n = 0; tail != head; n++) {
406		if (u_wc)
407			u_wc->uqueue[n] = old_u_wc->uqueue[tail];
408		else
409			k_wc->kqueue[n] = old_k_wc->kqueue[tail];
410		if (tail == (u32)cq->ibcq.cqe)
411			tail = 0;
412		else
413			tail++;
414	}
415	cq->ibcq.cqe = cqe;
416	if (u_wc) {
417		RDMA_WRITE_UAPI_ATOMIC(u_wc->head, n);
418		RDMA_WRITE_UAPI_ATOMIC(u_wc->tail, 0);
419		cq->queue = u_wc;
420	} else {
421		k_wc->head = n;
422		k_wc->tail = 0;
423		cq->kqueue = k_wc;
424	}
425	spin_unlock_irq(&cq->lock);
426
427	if (u_wc)
428		vfree(old_u_wc);
429	else
430		vfree(old_k_wc);
431
432	if (cq->ip) {
433		struct rvt_mmap_info *ip = cq->ip;
434
435		rvt_update_mmap_info(rdi, ip, sz, u_wc);
436
437		/*
438		 * Return the offset to mmap.
439		 * See rvt_mmap() for details.
440		 */
441		if (udata && udata->outlen >= sizeof(__u64)) {
442			ret = ib_copy_to_udata(udata, &ip->offset,
443					       sizeof(ip->offset));
444			if (ret)
445				return ret;
446		}
447
448		spin_lock_irq(&rdi->pending_lock);
449		if (list_empty(&ip->pending_mmaps))
450			list_add(&ip->pending_mmaps, &rdi->pending_mmaps);
451		spin_unlock_irq(&rdi->pending_lock);
452	}
453
454	return 0;
455
456bail_unlock:
457	spin_unlock_irq(&cq->lock);
458bail_free:
459	vfree(u_wc);
460	vfree(k_wc);
461
462	return ret;
463}
464
465/**
466 * rvt_poll_cq - poll for work completion entries
467 * @ibcq: the completion queue to poll
468 * @num_entries: the maximum number of entries to return
469 * @entry: pointer to array where work completions are placed
470 *
471 * This may be called from interrupt context.  Also called by ib_poll_cq()
472 * in the generic verbs code.
473 *
474 * Return: the number of completion entries polled.
475 */
476int rvt_poll_cq(struct ib_cq *ibcq, int num_entries, struct ib_wc *entry)
477{
478	struct rvt_cq *cq = ibcq_to_rvtcq(ibcq);
479	struct rvt_k_cq_wc *wc;
480	unsigned long flags;
481	int npolled;
482	u32 tail;
483
484	/* The kernel can only poll a kernel completion queue */
485	if (cq->ip)
486		return -EINVAL;
487
488	spin_lock_irqsave(&cq->lock, flags);
489
490	wc = cq->kqueue;
491	tail = wc->tail;
492	if (tail > (u32)cq->ibcq.cqe)
493		tail = (u32)cq->ibcq.cqe;
494	for (npolled = 0; npolled < num_entries; ++npolled, ++entry) {
495		if (tail == wc->head)
496			break;
497		/* The kernel doesn't need a RMB since it has the lock. */
498		trace_rvt_cq_poll(cq, &wc->kqueue[tail], npolled);
499		*entry = wc->kqueue[tail];
500		if (tail >= cq->ibcq.cqe)
501			tail = 0;
502		else
503			tail++;
504	}
505	wc->tail = tail;
506
507	spin_unlock_irqrestore(&cq->lock, flags);
508
509	return npolled;
510}
511
512/**
513 * rvt_driver_cq_init - Init cq resources on behalf of driver
514 *
515 * Return: 0 on success
516 */
517int rvt_driver_cq_init(void)
518{
519	comp_vector_wq = alloc_workqueue("%s", WQ_HIGHPRI | WQ_CPU_INTENSIVE,
520					 0, "rdmavt_cq");
521	if (!comp_vector_wq)
522		return -ENOMEM;
523
524	return 0;
525}
526
527/**
528 * rvt_cq_exit - tear down cq reources
529 */
530void rvt_cq_exit(void)
531{
532	destroy_workqueue(comp_vector_wq);
533	comp_vector_wq = NULL;
534}
535