xref: /linux/net/rds/ib_frmr.c (revision c0b2826aa02a0747c3016457b9c1917ba14d0655)
1 /*
2  * Copyright (c) 2016 Oracle.  All rights reserved.
3  *
4  * This software is available to you under a choice of one of two
5  * licenses.  You may choose to be licensed under the terms of the GNU
6  * General Public License (GPL) Version 2, available from the file
7  * COPYING in the main directory of this source tree, or the
8  * OpenIB.org BSD license below:
9  *
10  *     Redistribution and use in source and binary forms, with or
11  *     without modification, are permitted provided that the following
12  *     conditions are met:
13  *
14  *      - Redistributions of source code must retain the above
15  *        copyright notice, this list of conditions and the following
16  *        disclaimer.
17  *
18  *      - Redistributions in binary form must reproduce the above
19  *        copyright notice, this list of conditions and the following
20  *        disclaimer in the documentation and/or other materials
21  *        provided with the distribution.
22  *
23  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
24  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
25  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
26  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
27  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
28  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
29  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
30  * SOFTWARE.
31  */
32 
33 #include "ib_mr.h"
34 
35 static struct rds_ib_mr *rds_ib_alloc_frmr(struct rds_ib_device *rds_ibdev,
36 					   int npages)
37 {
38 	struct rds_ib_mr_pool *pool;
39 	struct rds_ib_mr *ibmr = NULL;
40 	struct rds_ib_frmr *frmr;
41 	int err = 0;
42 
43 	if (npages <= RDS_MR_8K_MSG_SIZE)
44 		pool = rds_ibdev->mr_8k_pool;
45 	else
46 		pool = rds_ibdev->mr_1m_pool;
47 
48 	ibmr = rds_ib_try_reuse_ibmr(pool);
49 	if (ibmr)
50 		return ibmr;
51 
52 	ibmr = kzalloc_node(sizeof(*ibmr), GFP_KERNEL,
53 			    rdsibdev_to_node(rds_ibdev));
54 	if (!ibmr) {
55 		err = -ENOMEM;
56 		goto out_no_cigar;
57 	}
58 
59 	frmr = &ibmr->u.frmr;
60 	frmr->mr = ib_alloc_mr(rds_ibdev->pd, IB_MR_TYPE_MEM_REG,
61 			 pool->fmr_attr.max_pages);
62 	if (IS_ERR(frmr->mr)) {
63 		pr_warn("RDS/IB: %s failed to allocate MR", __func__);
64 		err = PTR_ERR(frmr->mr);
65 		goto out_no_cigar;
66 	}
67 
68 	ibmr->pool = pool;
69 	if (pool->pool_type == RDS_IB_MR_8K_POOL)
70 		rds_ib_stats_inc(s_ib_rdma_mr_8k_alloc);
71 	else
72 		rds_ib_stats_inc(s_ib_rdma_mr_1m_alloc);
73 
74 	if (atomic_read(&pool->item_count) > pool->max_items_soft)
75 		pool->max_items_soft = pool->max_items;
76 
77 	frmr->fr_state = FRMR_IS_FREE;
78 	return ibmr;
79 
80 out_no_cigar:
81 	kfree(ibmr);
82 	atomic_dec(&pool->item_count);
83 	return ERR_PTR(err);
84 }
85 
86 static void rds_ib_free_frmr(struct rds_ib_mr *ibmr, bool drop)
87 {
88 	struct rds_ib_mr_pool *pool = ibmr->pool;
89 
90 	if (drop)
91 		llist_add(&ibmr->llnode, &pool->drop_list);
92 	else
93 		llist_add(&ibmr->llnode, &pool->free_list);
94 	atomic_add(ibmr->sg_len, &pool->free_pinned);
95 	atomic_inc(&pool->dirty_count);
96 
97 	/* If we've pinned too many pages, request a flush */
98 	if (atomic_read(&pool->free_pinned) >= pool->max_free_pinned ||
99 	    atomic_read(&pool->dirty_count) >= pool->max_items / 5)
100 		queue_delayed_work(rds_ib_mr_wq, &pool->flush_worker, 10);
101 }
102 
103 static int rds_ib_post_reg_frmr(struct rds_ib_mr *ibmr)
104 {
105 	struct rds_ib_frmr *frmr = &ibmr->u.frmr;
106 	struct ib_reg_wr reg_wr;
107 	int ret, off = 0;
108 
109 	while (atomic_dec_return(&ibmr->ic->i_fastreg_wrs) <= 0) {
110 		atomic_inc(&ibmr->ic->i_fastreg_wrs);
111 		cpu_relax();
112 	}
113 
114 	ret = ib_map_mr_sg_zbva(frmr->mr, ibmr->sg, ibmr->sg_len,
115 				&off, PAGE_SIZE);
116 	if (unlikely(ret != ibmr->sg_len))
117 		return ret < 0 ? ret : -EINVAL;
118 
119 	/* Perform a WR for the fast_reg_mr. Each individual page
120 	 * in the sg list is added to the fast reg page list and placed
121 	 * inside the fast_reg_mr WR.  The key used is a rolling 8bit
122 	 * counter, which should guarantee uniqueness.
123 	 */
124 	ib_update_fast_reg_key(frmr->mr, ibmr->remap_count++);
125 	frmr->fr_state = FRMR_IS_INUSE;
126 
127 	memset(&reg_wr, 0, sizeof(reg_wr));
128 	reg_wr.wr.wr_id = (unsigned long)(void *)ibmr;
129 	reg_wr.wr.opcode = IB_WR_REG_MR;
130 	reg_wr.wr.num_sge = 0;
131 	reg_wr.mr = frmr->mr;
132 	reg_wr.key = frmr->mr->rkey;
133 	reg_wr.access = IB_ACCESS_LOCAL_WRITE |
134 			IB_ACCESS_REMOTE_READ |
135 			IB_ACCESS_REMOTE_WRITE;
136 	reg_wr.wr.send_flags = IB_SEND_SIGNALED;
137 
138 	ret = ib_post_send(ibmr->ic->i_cm_id->qp, &reg_wr.wr, NULL);
139 	if (unlikely(ret)) {
140 		/* Failure here can be because of -ENOMEM as well */
141 		frmr->fr_state = FRMR_IS_STALE;
142 		atomic_inc(&ibmr->ic->i_fastreg_wrs);
143 		if (printk_ratelimit())
144 			pr_warn("RDS/IB: %s returned error(%d)\n",
145 				__func__, ret);
146 	}
147 	return ret;
148 }
149 
150 static int rds_ib_map_frmr(struct rds_ib_device *rds_ibdev,
151 			   struct rds_ib_mr_pool *pool,
152 			   struct rds_ib_mr *ibmr,
153 			   struct scatterlist *sg, unsigned int sg_len)
154 {
155 	struct ib_device *dev = rds_ibdev->dev;
156 	struct rds_ib_frmr *frmr = &ibmr->u.frmr;
157 	int i;
158 	u32 len;
159 	int ret = 0;
160 
161 	/* We want to teardown old ibmr values here and fill it up with
162 	 * new sg values
163 	 */
164 	rds_ib_teardown_mr(ibmr);
165 
166 	ibmr->sg = sg;
167 	ibmr->sg_len = sg_len;
168 	ibmr->sg_dma_len = 0;
169 	frmr->sg_byte_len = 0;
170 	WARN_ON(ibmr->sg_dma_len);
171 	ibmr->sg_dma_len = ib_dma_map_sg(dev, ibmr->sg, ibmr->sg_len,
172 					 DMA_BIDIRECTIONAL);
173 	if (unlikely(!ibmr->sg_dma_len)) {
174 		pr_warn("RDS/IB: %s failed!\n", __func__);
175 		return -EBUSY;
176 	}
177 
178 	frmr->sg_byte_len = 0;
179 	frmr->dma_npages = 0;
180 	len = 0;
181 
182 	ret = -EINVAL;
183 	for (i = 0; i < ibmr->sg_dma_len; ++i) {
184 		unsigned int dma_len = ib_sg_dma_len(dev, &ibmr->sg[i]);
185 		u64 dma_addr = ib_sg_dma_address(dev, &ibmr->sg[i]);
186 
187 		frmr->sg_byte_len += dma_len;
188 		if (dma_addr & ~PAGE_MASK) {
189 			if (i > 0)
190 				goto out_unmap;
191 			else
192 				++frmr->dma_npages;
193 		}
194 
195 		if ((dma_addr + dma_len) & ~PAGE_MASK) {
196 			if (i < ibmr->sg_dma_len - 1)
197 				goto out_unmap;
198 			else
199 				++frmr->dma_npages;
200 		}
201 
202 		len += dma_len;
203 	}
204 	frmr->dma_npages += len >> PAGE_SHIFT;
205 
206 	if (frmr->dma_npages > ibmr->pool->fmr_attr.max_pages) {
207 		ret = -EMSGSIZE;
208 		goto out_unmap;
209 	}
210 
211 	ret = rds_ib_post_reg_frmr(ibmr);
212 	if (ret)
213 		goto out_unmap;
214 
215 	if (ibmr->pool->pool_type == RDS_IB_MR_8K_POOL)
216 		rds_ib_stats_inc(s_ib_rdma_mr_8k_used);
217 	else
218 		rds_ib_stats_inc(s_ib_rdma_mr_1m_used);
219 
220 	return ret;
221 
222 out_unmap:
223 	ib_dma_unmap_sg(rds_ibdev->dev, ibmr->sg, ibmr->sg_len,
224 			DMA_BIDIRECTIONAL);
225 	ibmr->sg_dma_len = 0;
226 	return ret;
227 }
228 
229 static int rds_ib_post_inv(struct rds_ib_mr *ibmr)
230 {
231 	struct ib_send_wr *s_wr;
232 	struct rds_ib_frmr *frmr = &ibmr->u.frmr;
233 	struct rdma_cm_id *i_cm_id = ibmr->ic->i_cm_id;
234 	int ret = -EINVAL;
235 
236 	if (!i_cm_id || !i_cm_id->qp || !frmr->mr)
237 		goto out;
238 
239 	if (frmr->fr_state != FRMR_IS_INUSE)
240 		goto out;
241 
242 	while (atomic_dec_return(&ibmr->ic->i_fastunreg_wrs) <= 0) {
243 		atomic_inc(&ibmr->ic->i_fastunreg_wrs);
244 		cpu_relax();
245 	}
246 
247 	frmr->fr_inv = true;
248 	s_wr = &frmr->fr_wr;
249 
250 	memset(s_wr, 0, sizeof(*s_wr));
251 	s_wr->wr_id = (unsigned long)(void *)ibmr;
252 	s_wr->opcode = IB_WR_LOCAL_INV;
253 	s_wr->ex.invalidate_rkey = frmr->mr->rkey;
254 	s_wr->send_flags = IB_SEND_SIGNALED;
255 
256 	ret = ib_post_send(i_cm_id->qp, s_wr, NULL);
257 	if (unlikely(ret)) {
258 		frmr->fr_state = FRMR_IS_STALE;
259 		frmr->fr_inv = false;
260 		atomic_inc(&ibmr->ic->i_fastunreg_wrs);
261 		pr_err("RDS/IB: %s returned error(%d)\n", __func__, ret);
262 		goto out;
263 	}
264 out:
265 	return ret;
266 }
267 
268 void rds_ib_mr_cqe_handler(struct rds_ib_connection *ic, struct ib_wc *wc)
269 {
270 	struct rds_ib_mr *ibmr = (void *)(unsigned long)wc->wr_id;
271 	struct rds_ib_frmr *frmr = &ibmr->u.frmr;
272 
273 	if (wc->status != IB_WC_SUCCESS) {
274 		frmr->fr_state = FRMR_IS_STALE;
275 		if (rds_conn_up(ic->conn))
276 			rds_ib_conn_error(ic->conn,
277 					  "frmr completion <%pI4,%pI4> status %u(%s), vendor_err 0x%x, disconnecting and reconnecting\n",
278 					  &ic->conn->c_laddr,
279 					  &ic->conn->c_faddr,
280 					  wc->status,
281 					  ib_wc_status_msg(wc->status),
282 					  wc->vendor_err);
283 	}
284 
285 	if (frmr->fr_inv) {
286 		frmr->fr_state = FRMR_IS_FREE;
287 		frmr->fr_inv = false;
288 		atomic_inc(&ic->i_fastreg_wrs);
289 	} else {
290 		atomic_inc(&ic->i_fastunreg_wrs);
291 	}
292 }
293 
294 void rds_ib_unreg_frmr(struct list_head *list, unsigned int *nfreed,
295 		       unsigned long *unpinned, unsigned int goal)
296 {
297 	struct rds_ib_mr *ibmr, *next;
298 	struct rds_ib_frmr *frmr;
299 	int ret = 0;
300 	unsigned int freed = *nfreed;
301 
302 	/* String all ib_mr's onto one list and hand them to ib_unmap_fmr */
303 	list_for_each_entry(ibmr, list, unmap_list) {
304 		if (ibmr->sg_dma_len)
305 			ret |= rds_ib_post_inv(ibmr);
306 	}
307 	if (ret)
308 		pr_warn("RDS/IB: %s failed (err=%d)\n", __func__, ret);
309 
310 	/* Now we can destroy the DMA mapping and unpin any pages */
311 	list_for_each_entry_safe(ibmr, next, list, unmap_list) {
312 		*unpinned += ibmr->sg_len;
313 		frmr = &ibmr->u.frmr;
314 		__rds_ib_teardown_mr(ibmr);
315 		if (freed < goal || frmr->fr_state == FRMR_IS_STALE) {
316 			/* Don't de-allocate if the MR is not free yet */
317 			if (frmr->fr_state == FRMR_IS_INUSE)
318 				continue;
319 
320 			if (ibmr->pool->pool_type == RDS_IB_MR_8K_POOL)
321 				rds_ib_stats_inc(s_ib_rdma_mr_8k_free);
322 			else
323 				rds_ib_stats_inc(s_ib_rdma_mr_1m_free);
324 			list_del(&ibmr->unmap_list);
325 			if (frmr->mr)
326 				ib_dereg_mr(frmr->mr);
327 			kfree(ibmr);
328 			freed++;
329 		}
330 	}
331 	*nfreed = freed;
332 }
333 
334 struct rds_ib_mr *rds_ib_reg_frmr(struct rds_ib_device *rds_ibdev,
335 				  struct rds_ib_connection *ic,
336 				  struct scatterlist *sg,
337 				  unsigned long nents, u32 *key)
338 {
339 	struct rds_ib_mr *ibmr = NULL;
340 	struct rds_ib_frmr *frmr;
341 	int ret;
342 
343 	if (!ic) {
344 		/* TODO: Add FRWR support for RDS_GET_MR using proxy qp*/
345 		return ERR_PTR(-EOPNOTSUPP);
346 	}
347 
348 	do {
349 		if (ibmr)
350 			rds_ib_free_frmr(ibmr, true);
351 		ibmr = rds_ib_alloc_frmr(rds_ibdev, nents);
352 		if (IS_ERR(ibmr))
353 			return ibmr;
354 		frmr = &ibmr->u.frmr;
355 	} while (frmr->fr_state != FRMR_IS_FREE);
356 
357 	ibmr->ic = ic;
358 	ibmr->device = rds_ibdev;
359 	ret = rds_ib_map_frmr(rds_ibdev, ibmr->pool, ibmr, sg, nents);
360 	if (ret == 0) {
361 		*key = frmr->mr->rkey;
362 	} else {
363 		rds_ib_free_frmr(ibmr, false);
364 		ibmr = ERR_PTR(ret);
365 	}
366 
367 	return ibmr;
368 }
369 
370 void rds_ib_free_frmr_list(struct rds_ib_mr *ibmr)
371 {
372 	struct rds_ib_mr_pool *pool = ibmr->pool;
373 	struct rds_ib_frmr *frmr = &ibmr->u.frmr;
374 
375 	if (frmr->fr_state == FRMR_IS_STALE)
376 		llist_add(&ibmr->llnode, &pool->drop_list);
377 	else
378 		llist_add(&ibmr->llnode, &pool->free_list);
379 }
380