1/*
2 * Copyright (c) 2006, 2007, 2009 QLogic Corporation. All rights reserved.
3 * Copyright (c) 2005, 2006 PathScale, Inc. All rights reserved.
4 *
5 * This software is available to you under a choice of one of two
6 * licenses.  You may choose to be licensed under the terms of the GNU
7 * General Public License (GPL) Version 2, available from the file
8 * COPYING in the main directory of this source tree, or the
9 * OpenIB.org BSD license below:
10 *
11 *     Redistribution and use in source and binary forms, with or
12 *     without modification, are permitted provided that the following
13 *     conditions are met:
14 *
15 *      - Redistributions of source code must retain the above
16 *        copyright notice, this list of conditions and the following
17 *        disclaimer.
18 *
19 *      - Redistributions in binary form must reproduce the above
20 *        copyright notice, this list of conditions and the following
21 *        disclaimer in the documentation and/or other materials
22 *        provided with the distribution.
23 *
24 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
25 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
26 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
27 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
28 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
29 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
30 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
31 * SOFTWARE.
32 */
33
34#include "qib.h"
35
36/**
37 * qib_alloc_lkey - allocate an lkey
38 * @mr: memory region that this lkey protects
39 * @dma_region: 0->normal key, 1->restricted DMA key
40 *
41 * Returns 0 if successful, otherwise returns -errno.
42 *
43 * Increments mr reference count as required.
44 *
45 * Sets the lkey field mr for non-dma regions.
46 *
47 */
48
49int qib_alloc_lkey(struct qib_mregion *mr, int dma_region)
50{
51	unsigned long flags;
52	u32 r;
53	u32 n;
54	int ret = 0;
55	struct qib_ibdev *dev = to_idev(mr->pd->device);
56	struct qib_lkey_table *rkt = &dev->lk_table;
57
58	spin_lock_irqsave(&rkt->lock, flags);
59
60	/* special case for dma_mr lkey == 0 */
61	if (dma_region) {
62		struct qib_mregion *tmr;
63
64		tmr = rcu_access_pointer(dev->dma_mr);
65		if (!tmr) {
66			qib_get_mr(mr);
67			rcu_assign_pointer(dev->dma_mr, mr);
68			mr->lkey_published = 1;
69		}
70		goto success;
71	}
72
73	/* Find the next available LKEY */
74	r = rkt->next;
75	n = r;
76	for (;;) {
77		if (rkt->table[r] == NULL)
78			break;
79		r = (r + 1) & (rkt->max - 1);
80		if (r == n)
81			goto bail;
82	}
83	rkt->next = (r + 1) & (rkt->max - 1);
84	/*
85	 * Make sure lkey is never zero which is reserved to indicate an
86	 * unrestricted LKEY.
87	 */
88	rkt->gen++;
89	/*
90	 * bits are capped in qib_verbs.c to insure enough bits
91	 * for generation number
92	 */
93	mr->lkey = (r << (32 - ib_qib_lkey_table_size)) |
94		((((1 << (24 - ib_qib_lkey_table_size)) - 1) & rkt->gen)
95		 << 8);
96	if (mr->lkey == 0) {
97		mr->lkey |= 1 << 8;
98		rkt->gen++;
99	}
100	qib_get_mr(mr);
101	rcu_assign_pointer(rkt->table[r], mr);
102	mr->lkey_published = 1;
103success:
104	spin_unlock_irqrestore(&rkt->lock, flags);
105out:
106	return ret;
107bail:
108	spin_unlock_irqrestore(&rkt->lock, flags);
109	ret = -ENOMEM;
110	goto out;
111}
112
113/**
114 * qib_free_lkey - free an lkey
115 * @mr: mr to free from tables
116 */
117void qib_free_lkey(struct qib_mregion *mr)
118{
119	unsigned long flags;
120	u32 lkey = mr->lkey;
121	u32 r;
122	struct qib_ibdev *dev = to_idev(mr->pd->device);
123	struct qib_lkey_table *rkt = &dev->lk_table;
124
125	spin_lock_irqsave(&rkt->lock, flags);
126	if (!mr->lkey_published)
127		goto out;
128	if (lkey == 0)
129		RCU_INIT_POINTER(dev->dma_mr, NULL);
130	else {
131		r = lkey >> (32 - ib_qib_lkey_table_size);
132		RCU_INIT_POINTER(rkt->table[r], NULL);
133	}
134	qib_put_mr(mr);
135	mr->lkey_published = 0;
136out:
137	spin_unlock_irqrestore(&rkt->lock, flags);
138}
139
140/**
141 * qib_lkey_ok - check IB SGE for validity and initialize
142 * @rkt: table containing lkey to check SGE against
143 * @pd: protection domain
144 * @isge: outgoing internal SGE
145 * @sge: SGE to check
146 * @acc: access flags
147 *
148 * Return 1 if valid and successful, otherwise returns 0.
149 *
150 * increments the reference count upon success
151 *
152 * Check the IB SGE for validity and initialize our internal version
153 * of it.
154 */
155int qib_lkey_ok(struct qib_lkey_table *rkt, struct qib_pd *pd,
156		struct qib_sge *isge, struct ib_sge *sge, int acc)
157{
158	struct qib_mregion *mr;
159	unsigned n, m;
160	size_t off;
161
162	/*
163	 * We use LKEY == zero for kernel virtual addresses
164	 * (see qib_get_dma_mr and qib_dma.c).
165	 */
166	rcu_read_lock();
167	if (sge->lkey == 0) {
168		struct qib_ibdev *dev = to_idev(pd->ibpd.device);
169
170		if (pd->user)
171			goto bail;
172		mr = rcu_dereference(dev->dma_mr);
173		if (!mr)
174			goto bail;
175		if (unlikely(!atomic_inc_not_zero(&mr->refcount)))
176			goto bail;
177		rcu_read_unlock();
178
179		isge->mr = mr;
180		isge->vaddr = (void *) sge->addr;
181		isge->length = sge->length;
182		isge->sge_length = sge->length;
183		isge->m = 0;
184		isge->n = 0;
185		goto ok;
186	}
187	mr = rcu_dereference(
188		rkt->table[(sge->lkey >> (32 - ib_qib_lkey_table_size))]);
189	if (unlikely(!mr || mr->lkey != sge->lkey || mr->pd != &pd->ibpd))
190		goto bail;
191
192	off = sge->addr - mr->user_base;
193	if (unlikely(sge->addr < mr->user_base ||
194		     off + sge->length > mr->length ||
195		     (mr->access_flags & acc) != acc))
196		goto bail;
197	if (unlikely(!atomic_inc_not_zero(&mr->refcount)))
198		goto bail;
199	rcu_read_unlock();
200
201	off += mr->offset;
202	if (mr->page_shift) {
203		/*
204		page sizes are uniform power of 2 so no loop is necessary
205		entries_spanned_by_off is the number of times the loop below
206		would have executed.
207		*/
208		size_t entries_spanned_by_off;
209
210		entries_spanned_by_off = off >> mr->page_shift;
211		off -= (entries_spanned_by_off << mr->page_shift);
212		m = entries_spanned_by_off/QIB_SEGSZ;
213		n = entries_spanned_by_off%QIB_SEGSZ;
214	} else {
215		m = 0;
216		n = 0;
217		while (off >= mr->map[m]->segs[n].length) {
218			off -= mr->map[m]->segs[n].length;
219			n++;
220			if (n >= QIB_SEGSZ) {
221				m++;
222				n = 0;
223			}
224		}
225	}
226	isge->mr = mr;
227	isge->vaddr = mr->map[m]->segs[n].vaddr + off;
228	isge->length = mr->map[m]->segs[n].length - off;
229	isge->sge_length = sge->length;
230	isge->m = m;
231	isge->n = n;
232ok:
233	return 1;
234bail:
235	rcu_read_unlock();
236	return 0;
237}
238
239/**
240 * qib_rkey_ok - check the IB virtual address, length, and RKEY
241 * @qp: qp for validation
242 * @sge: SGE state
243 * @len: length of data
244 * @vaddr: virtual address to place data
245 * @rkey: rkey to check
246 * @acc: access flags
247 *
248 * Return 1 if successful, otherwise 0.
249 *
250 * increments the reference count upon success
251 */
252int qib_rkey_ok(struct qib_qp *qp, struct qib_sge *sge,
253		u32 len, u64 vaddr, u32 rkey, int acc)
254{
255	struct qib_lkey_table *rkt = &to_idev(qp->ibqp.device)->lk_table;
256	struct qib_mregion *mr;
257	unsigned n, m;
258	size_t off;
259
260	/*
261	 * We use RKEY == zero for kernel virtual addresses
262	 * (see qib_get_dma_mr and qib_dma.c).
263	 */
264	rcu_read_lock();
265	if (rkey == 0) {
266		struct qib_pd *pd = to_ipd(qp->ibqp.pd);
267		struct qib_ibdev *dev = to_idev(pd->ibpd.device);
268
269		if (pd->user)
270			goto bail;
271		mr = rcu_dereference(dev->dma_mr);
272		if (!mr)
273			goto bail;
274		if (unlikely(!atomic_inc_not_zero(&mr->refcount)))
275			goto bail;
276		rcu_read_unlock();
277
278		sge->mr = mr;
279		sge->vaddr = (void *) vaddr;
280		sge->length = len;
281		sge->sge_length = len;
282		sge->m = 0;
283		sge->n = 0;
284		goto ok;
285	}
286
287	mr = rcu_dereference(
288		rkt->table[(rkey >> (32 - ib_qib_lkey_table_size))]);
289	if (unlikely(!mr || mr->lkey != rkey || qp->ibqp.pd != mr->pd))
290		goto bail;
291
292	off = vaddr - mr->iova;
293	if (unlikely(vaddr < mr->iova || off + len > mr->length ||
294		     (mr->access_flags & acc) == 0))
295		goto bail;
296	if (unlikely(!atomic_inc_not_zero(&mr->refcount)))
297		goto bail;
298	rcu_read_unlock();
299
300	off += mr->offset;
301	if (mr->page_shift) {
302		/*
303		page sizes are uniform power of 2 so no loop is necessary
304		entries_spanned_by_off is the number of times the loop below
305		would have executed.
306		*/
307		size_t entries_spanned_by_off;
308
309		entries_spanned_by_off = off >> mr->page_shift;
310		off -= (entries_spanned_by_off << mr->page_shift);
311		m = entries_spanned_by_off/QIB_SEGSZ;
312		n = entries_spanned_by_off%QIB_SEGSZ;
313	} else {
314		m = 0;
315		n = 0;
316		while (off >= mr->map[m]->segs[n].length) {
317			off -= mr->map[m]->segs[n].length;
318			n++;
319			if (n >= QIB_SEGSZ) {
320				m++;
321				n = 0;
322			}
323		}
324	}
325	sge->mr = mr;
326	sge->vaddr = mr->map[m]->segs[n].vaddr + off;
327	sge->length = mr->map[m]->segs[n].length - off;
328	sge->sge_length = len;
329	sge->m = m;
330	sge->n = n;
331ok:
332	return 1;
333bail:
334	rcu_read_unlock();
335	return 0;
336}
337
338/*
339 * Initialize the memory region specified by the work reqeust.
340 */
341int qib_fast_reg_mr(struct qib_qp *qp, struct ib_send_wr *wr)
342{
343	struct qib_lkey_table *rkt = &to_idev(qp->ibqp.device)->lk_table;
344	struct qib_pd *pd = to_ipd(qp->ibqp.pd);
345	struct qib_mregion *mr;
346	u32 rkey = wr->wr.fast_reg.rkey;
347	unsigned i, n, m;
348	int ret = -EINVAL;
349	unsigned long flags;
350	u64 *page_list;
351	size_t ps;
352
353	spin_lock_irqsave(&rkt->lock, flags);
354	if (pd->user || rkey == 0)
355		goto bail;
356
357	mr = rcu_dereference_protected(
358		rkt->table[(rkey >> (32 - ib_qib_lkey_table_size))],
359		lockdep_is_held(&rkt->lock));
360	if (unlikely(mr == NULL || qp->ibqp.pd != mr->pd))
361		goto bail;
362
363	if (wr->wr.fast_reg.page_list_len > mr->max_segs)
364		goto bail;
365
366	ps = 1UL << wr->wr.fast_reg.page_shift;
367	if (wr->wr.fast_reg.length > ps * wr->wr.fast_reg.page_list_len)
368		goto bail;
369
370	mr->user_base = wr->wr.fast_reg.iova_start;
371	mr->iova = wr->wr.fast_reg.iova_start;
372	mr->lkey = rkey;
373	mr->length = wr->wr.fast_reg.length;
374	mr->access_flags = wr->wr.fast_reg.access_flags;
375	page_list = wr->wr.fast_reg.page_list->page_list;
376	m = 0;
377	n = 0;
378	for (i = 0; i < wr->wr.fast_reg.page_list_len; i++) {
379		mr->map[m]->segs[n].vaddr = (void *) page_list[i];
380		mr->map[m]->segs[n].length = ps;
381		if (++n == QIB_SEGSZ) {
382			m++;
383			n = 0;
384		}
385	}
386
387	ret = 0;
388bail:
389	spin_unlock_irqrestore(&rkt->lock, flags);
390	return ret;
391}
392