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1 /*
2  * Copyright(c) 2020 - Cornelis Networks, Inc.
3  * Copyright(c) 2015 - 2018 Intel Corporation.
4  *
5  * This file is provided under a dual BSD/GPLv2 license.  When using or
6  * redistributing this file, you may do so under either license.
7  *
8  * GPL LICENSE SUMMARY
9  *
10  * This program is free software; you can redistribute it and/or modify
11  * it under the terms of version 2 of the GNU General Public License as
12  * published by the Free Software Foundation.
13  *
14  * This program is distributed in the hope that it will be useful, but
15  * WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
17  * General Public License for more details.
18  *
19  * BSD LICENSE
20  *
21  * Redistribution and use in source and binary forms, with or without
22  * modification, are permitted provided that the following conditions
23  * are met:
24  *
25  *  - Redistributions of source code must retain the above copyright
26  *    notice, this list of conditions and the following disclaimer.
27  *  - Redistributions in binary form must reproduce the above copyright
28  *    notice, this list of conditions and the following disclaimer in
29  *    the documentation and/or other materials provided with the
30  *    distribution.
31  *  - Neither the name of Intel Corporation nor the names of its
32  *    contributors may be used to endorse or promote products derived
33  *    from this software without specific prior written permission.
34  *
35  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
36  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
37  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
38  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
39  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
40  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
41  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
42  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
43  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
44  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
45  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
46  *
47  */
48 #include <linux/mm.h>
49 #include <linux/types.h>
50 #include <linux/device.h>
51 #include <linux/dmapool.h>
52 #include <linux/slab.h>
53 #include <linux/list.h>
54 #include <linux/highmem.h>
55 #include <linux/io.h>
56 #include <linux/uio.h>
57 #include <linux/rbtree.h>
58 #include <linux/spinlock.h>
59 #include <linux/delay.h>
60 #include <linux/kthread.h>
61 #include <linux/mmu_context.h>
62 #include <linux/module.h>
63 #include <linux/vmalloc.h>
64 #include <linux/string.h>
65 
66 #include "hfi.h"
67 #include "sdma.h"
68 #include "user_sdma.h"
69 #include "verbs.h"  /* for the headers */
70 #include "common.h" /* for struct hfi1_tid_info */
71 #include "trace.h"
72 
73 static uint hfi1_sdma_comp_ring_size = 128;
74 module_param_named(sdma_comp_size, hfi1_sdma_comp_ring_size, uint, S_IRUGO);
75 MODULE_PARM_DESC(sdma_comp_size, "Size of User SDMA completion ring. Default: 128");
76 
77 static unsigned initial_pkt_count = 8;
78 
79 static int user_sdma_send_pkts(struct user_sdma_request *req, u16 maxpkts);
80 static void user_sdma_txreq_cb(struct sdma_txreq *txreq, int status);
81 static inline void pq_update(struct hfi1_user_sdma_pkt_q *pq);
82 static void user_sdma_free_request(struct user_sdma_request *req);
83 static int check_header_template(struct user_sdma_request *req,
84 				 struct hfi1_pkt_header *hdr, u32 lrhlen,
85 				 u32 datalen);
86 static int set_txreq_header(struct user_sdma_request *req,
87 			    struct user_sdma_txreq *tx, u32 datalen);
88 static int set_txreq_header_ahg(struct user_sdma_request *req,
89 				struct user_sdma_txreq *tx, u32 len);
90 static inline void set_comp_state(struct hfi1_user_sdma_pkt_q *pq,
91 				  struct hfi1_user_sdma_comp_q *cq,
92 				  u16 idx, enum hfi1_sdma_comp_state state,
93 				  int ret);
94 static inline u32 set_pkt_bth_psn(__be32 bthpsn, u8 expct, u32 frags);
95 static inline u32 get_lrh_len(struct hfi1_pkt_header, u32 len);
96 
97 static int defer_packet_queue(
98 	struct sdma_engine *sde,
99 	struct iowait_work *wait,
100 	struct sdma_txreq *txreq,
101 	uint seq,
102 	bool pkts_sent);
103 static void activate_packet_queue(struct iowait *wait, int reason);
104 static bool sdma_rb_filter(struct mmu_rb_node *node, unsigned long addr,
105 			   unsigned long len);
106 static int sdma_rb_evict(void *arg, struct mmu_rb_node *mnode,
107 			 void *arg2, bool *stop);
108 static void sdma_rb_remove(void *arg, struct mmu_rb_node *mnode);
109 
110 static struct mmu_rb_ops sdma_rb_ops = {
111 	.filter = sdma_rb_filter,
112 	.evict = sdma_rb_evict,
113 	.remove = sdma_rb_remove,
114 };
115 
116 static int add_system_pages_to_sdma_packet(struct user_sdma_request *req,
117 					   struct user_sdma_txreq *tx,
118 					   struct user_sdma_iovec *iovec,
119 					   u32 *pkt_remaining);
120 
defer_packet_queue(struct sdma_engine * sde,struct iowait_work * wait,struct sdma_txreq * txreq,uint seq,bool pkts_sent)121 static int defer_packet_queue(
122 	struct sdma_engine *sde,
123 	struct iowait_work *wait,
124 	struct sdma_txreq *txreq,
125 	uint seq,
126 	bool pkts_sent)
127 {
128 	struct hfi1_user_sdma_pkt_q *pq =
129 		container_of(wait->iow, struct hfi1_user_sdma_pkt_q, busy);
130 
131 	write_seqlock(&sde->waitlock);
132 	trace_hfi1_usdma_defer(pq, sde, &pq->busy);
133 	if (sdma_progress(sde, seq, txreq))
134 		goto eagain;
135 	/*
136 	 * We are assuming that if the list is enqueued somewhere, it
137 	 * is to the dmawait list since that is the only place where
138 	 * it is supposed to be enqueued.
139 	 */
140 	xchg(&pq->state, SDMA_PKT_Q_DEFERRED);
141 	if (list_empty(&pq->busy.list)) {
142 		pq->busy.lock = &sde->waitlock;
143 		iowait_get_priority(&pq->busy);
144 		iowait_queue(pkts_sent, &pq->busy, &sde->dmawait);
145 	}
146 	write_sequnlock(&sde->waitlock);
147 	return -EBUSY;
148 eagain:
149 	write_sequnlock(&sde->waitlock);
150 	return -EAGAIN;
151 }
152 
activate_packet_queue(struct iowait * wait,int reason)153 static void activate_packet_queue(struct iowait *wait, int reason)
154 {
155 	struct hfi1_user_sdma_pkt_q *pq =
156 		container_of(wait, struct hfi1_user_sdma_pkt_q, busy);
157 
158 	trace_hfi1_usdma_activate(pq, wait, reason);
159 	xchg(&pq->state, SDMA_PKT_Q_ACTIVE);
160 	wake_up(&wait->wait_dma);
161 };
162 
hfi1_user_sdma_alloc_queues(struct hfi1_ctxtdata * uctxt,struct hfi1_filedata * fd)163 int hfi1_user_sdma_alloc_queues(struct hfi1_ctxtdata *uctxt,
164 				struct hfi1_filedata *fd)
165 {
166 	int ret = -ENOMEM;
167 	char buf[64];
168 	struct hfi1_devdata *dd;
169 	struct hfi1_user_sdma_comp_q *cq;
170 	struct hfi1_user_sdma_pkt_q *pq;
171 
172 	if (!uctxt || !fd)
173 		return -EBADF;
174 
175 	if (!hfi1_sdma_comp_ring_size)
176 		return -EINVAL;
177 
178 	dd = uctxt->dd;
179 
180 	pq = kzalloc(sizeof(*pq), GFP_KERNEL);
181 	if (!pq)
182 		return -ENOMEM;
183 	pq->dd = dd;
184 	pq->ctxt = uctxt->ctxt;
185 	pq->subctxt = fd->subctxt;
186 	pq->n_max_reqs = hfi1_sdma_comp_ring_size;
187 	atomic_set(&pq->n_reqs, 0);
188 	init_waitqueue_head(&pq->wait);
189 	atomic_set(&pq->n_locked, 0);
190 
191 	iowait_init(&pq->busy, 0, NULL, NULL, defer_packet_queue,
192 		    activate_packet_queue, NULL, NULL);
193 	pq->reqidx = 0;
194 
195 	pq->reqs = kcalloc(hfi1_sdma_comp_ring_size,
196 			   sizeof(*pq->reqs),
197 			   GFP_KERNEL);
198 	if (!pq->reqs)
199 		goto pq_reqs_nomem;
200 
201 	pq->req_in_use = bitmap_zalloc(hfi1_sdma_comp_ring_size, GFP_KERNEL);
202 	if (!pq->req_in_use)
203 		goto pq_reqs_no_in_use;
204 
205 	snprintf(buf, 64, "txreq-kmem-cache-%u-%u-%u", dd->unit, uctxt->ctxt,
206 		 fd->subctxt);
207 	pq->txreq_cache = kmem_cache_create(buf,
208 					    sizeof(struct user_sdma_txreq),
209 					    L1_CACHE_BYTES,
210 					    SLAB_HWCACHE_ALIGN,
211 					    NULL);
212 	if (!pq->txreq_cache) {
213 		dd_dev_err(dd, "[%u] Failed to allocate TxReq cache\n",
214 			   uctxt->ctxt);
215 		goto pq_txreq_nomem;
216 	}
217 
218 	cq = kzalloc(sizeof(*cq), GFP_KERNEL);
219 	if (!cq)
220 		goto cq_nomem;
221 
222 	cq->comps = vmalloc_user(PAGE_ALIGN(sizeof(*cq->comps)
223 				 * hfi1_sdma_comp_ring_size));
224 	if (!cq->comps)
225 		goto cq_comps_nomem;
226 
227 	cq->nentries = hfi1_sdma_comp_ring_size;
228 
229 	ret = hfi1_mmu_rb_register(pq, &sdma_rb_ops, dd->pport->hfi1_wq,
230 				   &pq->handler);
231 	if (ret) {
232 		dd_dev_err(dd, "Failed to register with MMU %d", ret);
233 		goto pq_mmu_fail;
234 	}
235 
236 	rcu_assign_pointer(fd->pq, pq);
237 	fd->cq = cq;
238 
239 	return 0;
240 
241 pq_mmu_fail:
242 	vfree(cq->comps);
243 cq_comps_nomem:
244 	kfree(cq);
245 cq_nomem:
246 	kmem_cache_destroy(pq->txreq_cache);
247 pq_txreq_nomem:
248 	bitmap_free(pq->req_in_use);
249 pq_reqs_no_in_use:
250 	kfree(pq->reqs);
251 pq_reqs_nomem:
252 	kfree(pq);
253 
254 	return ret;
255 }
256 
flush_pq_iowait(struct hfi1_user_sdma_pkt_q * pq)257 static void flush_pq_iowait(struct hfi1_user_sdma_pkt_q *pq)
258 {
259 	unsigned long flags;
260 	seqlock_t *lock = pq->busy.lock;
261 
262 	if (!lock)
263 		return;
264 	write_seqlock_irqsave(lock, flags);
265 	if (!list_empty(&pq->busy.list)) {
266 		list_del_init(&pq->busy.list);
267 		pq->busy.lock = NULL;
268 	}
269 	write_sequnlock_irqrestore(lock, flags);
270 }
271 
hfi1_user_sdma_free_queues(struct hfi1_filedata * fd,struct hfi1_ctxtdata * uctxt)272 int hfi1_user_sdma_free_queues(struct hfi1_filedata *fd,
273 			       struct hfi1_ctxtdata *uctxt)
274 {
275 	struct hfi1_user_sdma_pkt_q *pq;
276 
277 	trace_hfi1_sdma_user_free_queues(uctxt->dd, uctxt->ctxt, fd->subctxt);
278 
279 	spin_lock(&fd->pq_rcu_lock);
280 	pq = srcu_dereference_check(fd->pq, &fd->pq_srcu,
281 				    lockdep_is_held(&fd->pq_rcu_lock));
282 	if (pq) {
283 		rcu_assign_pointer(fd->pq, NULL);
284 		spin_unlock(&fd->pq_rcu_lock);
285 		synchronize_srcu(&fd->pq_srcu);
286 		/* at this point there can be no more new requests */
287 		iowait_sdma_drain(&pq->busy);
288 		/* Wait until all requests have been freed. */
289 		wait_event_interruptible(
290 			pq->wait,
291 			!atomic_read(&pq->n_reqs));
292 		kfree(pq->reqs);
293 		if (pq->handler)
294 			hfi1_mmu_rb_unregister(pq->handler);
295 		bitmap_free(pq->req_in_use);
296 		kmem_cache_destroy(pq->txreq_cache);
297 		flush_pq_iowait(pq);
298 		kfree(pq);
299 	} else {
300 		spin_unlock(&fd->pq_rcu_lock);
301 	}
302 	if (fd->cq) {
303 		vfree(fd->cq->comps);
304 		kfree(fd->cq);
305 		fd->cq = NULL;
306 	}
307 	return 0;
308 }
309 
dlid_to_selector(u16 dlid)310 static u8 dlid_to_selector(u16 dlid)
311 {
312 	static u8 mapping[256];
313 	static int initialized;
314 	static u8 next;
315 	int hash;
316 
317 	if (!initialized) {
318 		memset(mapping, 0xFF, 256);
319 		initialized = 1;
320 	}
321 
322 	hash = ((dlid >> 8) ^ dlid) & 0xFF;
323 	if (mapping[hash] == 0xFF) {
324 		mapping[hash] = next;
325 		next = (next + 1) & 0x7F;
326 	}
327 
328 	return mapping[hash];
329 }
330 
331 /**
332  * hfi1_user_sdma_process_request() - Process and start a user sdma request
333  * @fd: valid file descriptor
334  * @iovec: array of io vectors to process
335  * @dim: overall iovec array size
336  * @count: number of io vector array entries processed
337  */
hfi1_user_sdma_process_request(struct hfi1_filedata * fd,struct iovec * iovec,unsigned long dim,unsigned long * count)338 int hfi1_user_sdma_process_request(struct hfi1_filedata *fd,
339 				   struct iovec *iovec, unsigned long dim,
340 				   unsigned long *count)
341 {
342 	int ret = 0, i;
343 	struct hfi1_ctxtdata *uctxt = fd->uctxt;
344 	struct hfi1_user_sdma_pkt_q *pq =
345 		srcu_dereference(fd->pq, &fd->pq_srcu);
346 	struct hfi1_user_sdma_comp_q *cq = fd->cq;
347 	struct hfi1_devdata *dd = pq->dd;
348 	unsigned long idx = 0;
349 	u8 pcount = initial_pkt_count;
350 	struct sdma_req_info info;
351 	struct user_sdma_request *req;
352 	u8 opcode, sc, vl;
353 	u16 pkey;
354 	u32 slid;
355 	u16 dlid;
356 	u32 selector;
357 
358 	if (iovec[idx].iov_len < sizeof(info) + sizeof(req->hdr)) {
359 		hfi1_cdbg(
360 		   SDMA,
361 		   "[%u:%u:%u] First vector not big enough for header %lu/%lu",
362 		   dd->unit, uctxt->ctxt, fd->subctxt,
363 		   iovec[idx].iov_len, sizeof(info) + sizeof(req->hdr));
364 		return -EINVAL;
365 	}
366 	ret = copy_from_user(&info, iovec[idx].iov_base, sizeof(info));
367 	if (ret) {
368 		hfi1_cdbg(SDMA, "[%u:%u:%u] Failed to copy info QW (%d)",
369 			  dd->unit, uctxt->ctxt, fd->subctxt, ret);
370 		return -EFAULT;
371 	}
372 
373 	trace_hfi1_sdma_user_reqinfo(dd, uctxt->ctxt, fd->subctxt,
374 				     (u16 *)&info);
375 	if (info.comp_idx >= hfi1_sdma_comp_ring_size) {
376 		hfi1_cdbg(SDMA,
377 			  "[%u:%u:%u:%u] Invalid comp index",
378 			  dd->unit, uctxt->ctxt, fd->subctxt, info.comp_idx);
379 		return -EINVAL;
380 	}
381 
382 	/*
383 	 * Sanity check the header io vector count.  Need at least 1 vector
384 	 * (header) and cannot be larger than the actual io vector count.
385 	 */
386 	if (req_iovcnt(info.ctrl) < 1 || req_iovcnt(info.ctrl) > dim) {
387 		hfi1_cdbg(SDMA,
388 			  "[%u:%u:%u:%u] Invalid iov count %d, dim %ld",
389 			  dd->unit, uctxt->ctxt, fd->subctxt, info.comp_idx,
390 			  req_iovcnt(info.ctrl), dim);
391 		return -EINVAL;
392 	}
393 
394 	if (!info.fragsize) {
395 		hfi1_cdbg(SDMA,
396 			  "[%u:%u:%u:%u] Request does not specify fragsize",
397 			  dd->unit, uctxt->ctxt, fd->subctxt, info.comp_idx);
398 		return -EINVAL;
399 	}
400 
401 	/* Try to claim the request. */
402 	if (test_and_set_bit(info.comp_idx, pq->req_in_use)) {
403 		hfi1_cdbg(SDMA, "[%u:%u:%u] Entry %u is in use",
404 			  dd->unit, uctxt->ctxt, fd->subctxt,
405 			  info.comp_idx);
406 		return -EBADSLT;
407 	}
408 	/*
409 	 * All safety checks have been done and this request has been claimed.
410 	 */
411 	trace_hfi1_sdma_user_process_request(dd, uctxt->ctxt, fd->subctxt,
412 					     info.comp_idx);
413 	req = pq->reqs + info.comp_idx;
414 	req->data_iovs = req_iovcnt(info.ctrl) - 1; /* subtract header vector */
415 	req->data_len  = 0;
416 	req->pq = pq;
417 	req->cq = cq;
418 	req->ahg_idx = -1;
419 	req->iov_idx = 0;
420 	req->sent = 0;
421 	req->seqnum = 0;
422 	req->seqcomp = 0;
423 	req->seqsubmitted = 0;
424 	req->tids = NULL;
425 	req->has_error = 0;
426 	INIT_LIST_HEAD(&req->txps);
427 
428 	memcpy(&req->info, &info, sizeof(info));
429 
430 	/* The request is initialized, count it */
431 	atomic_inc(&pq->n_reqs);
432 
433 	if (req_opcode(info.ctrl) == EXPECTED) {
434 		/* expected must have a TID info and at least one data vector */
435 		if (req->data_iovs < 2) {
436 			SDMA_DBG(req,
437 				 "Not enough vectors for expected request");
438 			ret = -EINVAL;
439 			goto free_req;
440 		}
441 		req->data_iovs--;
442 	}
443 
444 	if (!info.npkts || req->data_iovs > MAX_VECTORS_PER_REQ) {
445 		SDMA_DBG(req, "Too many vectors (%u/%u)", req->data_iovs,
446 			 MAX_VECTORS_PER_REQ);
447 		ret = -EINVAL;
448 		goto free_req;
449 	}
450 
451 	/* Copy the header from the user buffer */
452 	ret = copy_from_user(&req->hdr, iovec[idx].iov_base + sizeof(info),
453 			     sizeof(req->hdr));
454 	if (ret) {
455 		SDMA_DBG(req, "Failed to copy header template (%d)", ret);
456 		ret = -EFAULT;
457 		goto free_req;
458 	}
459 
460 	/* If Static rate control is not enabled, sanitize the header. */
461 	if (!HFI1_CAP_IS_USET(STATIC_RATE_CTRL))
462 		req->hdr.pbc[2] = 0;
463 
464 	/* Validate the opcode. Do not trust packets from user space blindly. */
465 	opcode = (be32_to_cpu(req->hdr.bth[0]) >> 24) & 0xff;
466 	if ((opcode & USER_OPCODE_CHECK_MASK) !=
467 	     USER_OPCODE_CHECK_VAL) {
468 		SDMA_DBG(req, "Invalid opcode (%d)", opcode);
469 		ret = -EINVAL;
470 		goto free_req;
471 	}
472 	/*
473 	 * Validate the vl. Do not trust packets from user space blindly.
474 	 * VL comes from PBC, SC comes from LRH, and the VL needs to
475 	 * match the SC look up.
476 	 */
477 	vl = (le16_to_cpu(req->hdr.pbc[0]) >> 12) & 0xF;
478 	sc = (((be16_to_cpu(req->hdr.lrh[0]) >> 12) & 0xF) |
479 	      (((le16_to_cpu(req->hdr.pbc[1]) >> 14) & 0x1) << 4));
480 	if (vl >= dd->pport->vls_operational ||
481 	    vl != sc_to_vlt(dd, sc)) {
482 		SDMA_DBG(req, "Invalid SC(%u)/VL(%u)", sc, vl);
483 		ret = -EINVAL;
484 		goto free_req;
485 	}
486 
487 	/* Checking P_KEY for requests from user-space */
488 	pkey = (u16)be32_to_cpu(req->hdr.bth[0]);
489 	slid = be16_to_cpu(req->hdr.lrh[3]);
490 	if (egress_pkey_check(dd->pport, slid, pkey, sc, PKEY_CHECK_INVALID)) {
491 		ret = -EINVAL;
492 		goto free_req;
493 	}
494 
495 	/*
496 	 * Also should check the BTH.lnh. If it says the next header is GRH then
497 	 * the RXE parsing will be off and will land in the middle of the KDETH
498 	 * or miss it entirely.
499 	 */
500 	if ((be16_to_cpu(req->hdr.lrh[0]) & 0x3) == HFI1_LRH_GRH) {
501 		SDMA_DBG(req, "User tried to pass in a GRH");
502 		ret = -EINVAL;
503 		goto free_req;
504 	}
505 
506 	req->koffset = le32_to_cpu(req->hdr.kdeth.swdata[6]);
507 	/*
508 	 * Calculate the initial TID offset based on the values of
509 	 * KDETH.OFFSET and KDETH.OM that are passed in.
510 	 */
511 	req->tidoffset = KDETH_GET(req->hdr.kdeth.ver_tid_offset, OFFSET) *
512 		(KDETH_GET(req->hdr.kdeth.ver_tid_offset, OM) ?
513 		 KDETH_OM_LARGE : KDETH_OM_SMALL);
514 	trace_hfi1_sdma_user_initial_tidoffset(dd, uctxt->ctxt, fd->subctxt,
515 					       info.comp_idx, req->tidoffset);
516 	idx++;
517 
518 	/* Save all the IO vector structures */
519 	for (i = 0; i < req->data_iovs; i++) {
520 		req->iovs[i].offset = 0;
521 		INIT_LIST_HEAD(&req->iovs[i].list);
522 		memcpy(&req->iovs[i].iov,
523 		       iovec + idx++,
524 		       sizeof(req->iovs[i].iov));
525 		if (req->iovs[i].iov.iov_len == 0) {
526 			ret = -EINVAL;
527 			goto free_req;
528 		}
529 		req->data_len += req->iovs[i].iov.iov_len;
530 	}
531 	trace_hfi1_sdma_user_data_length(dd, uctxt->ctxt, fd->subctxt,
532 					 info.comp_idx, req->data_len);
533 	if (pcount > req->info.npkts)
534 		pcount = req->info.npkts;
535 	/*
536 	 * Copy any TID info
537 	 * User space will provide the TID info only when the
538 	 * request type is EXPECTED. This is true even if there is
539 	 * only one packet in the request and the header is already
540 	 * setup. The reason for the singular TID case is that the
541 	 * driver needs to perform safety checks.
542 	 */
543 	if (req_opcode(req->info.ctrl) == EXPECTED) {
544 		u16 ntids = iovec[idx].iov_len / sizeof(*req->tids);
545 		u32 *tmp;
546 
547 		if (!ntids || ntids > MAX_TID_PAIR_ENTRIES) {
548 			ret = -EINVAL;
549 			goto free_req;
550 		}
551 
552 		/*
553 		 * We have to copy all of the tids because they may vary
554 		 * in size and, therefore, the TID count might not be
555 		 * equal to the pkt count. However, there is no way to
556 		 * tell at this point.
557 		 */
558 		tmp = memdup_user(iovec[idx].iov_base,
559 				  ntids * sizeof(*req->tids));
560 		if (IS_ERR(tmp)) {
561 			ret = PTR_ERR(tmp);
562 			SDMA_DBG(req, "Failed to copy %d TIDs (%d)",
563 				 ntids, ret);
564 			goto free_req;
565 		}
566 		req->tids = tmp;
567 		req->n_tids = ntids;
568 		req->tididx = 0;
569 		idx++;
570 	}
571 
572 	dlid = be16_to_cpu(req->hdr.lrh[1]);
573 	selector = dlid_to_selector(dlid);
574 	selector += uctxt->ctxt + fd->subctxt;
575 	req->sde = sdma_select_user_engine(dd, selector, vl);
576 
577 	if (!req->sde || !sdma_running(req->sde)) {
578 		ret = -ECOMM;
579 		goto free_req;
580 	}
581 
582 	/* We don't need an AHG entry if the request contains only one packet */
583 	if (req->info.npkts > 1 && HFI1_CAP_IS_USET(SDMA_AHG))
584 		req->ahg_idx = sdma_ahg_alloc(req->sde);
585 
586 	set_comp_state(pq, cq, info.comp_idx, QUEUED, 0);
587 	pq->state = SDMA_PKT_Q_ACTIVE;
588 
589 	/*
590 	 * This is a somewhat blocking send implementation.
591 	 * The driver will block the caller until all packets of the
592 	 * request have been submitted to the SDMA engine. However, it
593 	 * will not wait for send completions.
594 	 */
595 	while (req->seqsubmitted != req->info.npkts) {
596 		ret = user_sdma_send_pkts(req, pcount);
597 		if (ret < 0) {
598 			int we_ret;
599 
600 			if (ret != -EBUSY)
601 				goto free_req;
602 			we_ret = wait_event_interruptible_timeout(
603 				pq->busy.wait_dma,
604 				pq->state == SDMA_PKT_Q_ACTIVE,
605 				msecs_to_jiffies(
606 					SDMA_IOWAIT_TIMEOUT));
607 			trace_hfi1_usdma_we(pq, we_ret);
608 			if (we_ret <= 0)
609 				flush_pq_iowait(pq);
610 		}
611 	}
612 	*count += idx;
613 	return 0;
614 free_req:
615 	/*
616 	 * If the submitted seqsubmitted == npkts, the completion routine
617 	 * controls the final state.  If sequbmitted < npkts, wait for any
618 	 * outstanding packets to finish before cleaning up.
619 	 */
620 	if (req->seqsubmitted < req->info.npkts) {
621 		if (req->seqsubmitted)
622 			wait_event(pq->busy.wait_dma,
623 				   (req->seqcomp == req->seqsubmitted - 1));
624 		user_sdma_free_request(req);
625 		pq_update(pq);
626 		set_comp_state(pq, cq, info.comp_idx, ERROR, ret);
627 	}
628 	return ret;
629 }
630 
compute_data_length(struct user_sdma_request * req,struct user_sdma_txreq * tx)631 static inline u32 compute_data_length(struct user_sdma_request *req,
632 				      struct user_sdma_txreq *tx)
633 {
634 	/*
635 	 * Determine the proper size of the packet data.
636 	 * The size of the data of the first packet is in the header
637 	 * template. However, it includes the header and ICRC, which need
638 	 * to be subtracted.
639 	 * The minimum representable packet data length in a header is 4 bytes,
640 	 * therefore, when the data length request is less than 4 bytes, there's
641 	 * only one packet, and the packet data length is equal to that of the
642 	 * request data length.
643 	 * The size of the remaining packets is the minimum of the frag
644 	 * size (MTU) or remaining data in the request.
645 	 */
646 	u32 len;
647 
648 	if (!req->seqnum) {
649 		if (req->data_len < sizeof(u32))
650 			len = req->data_len;
651 		else
652 			len = ((be16_to_cpu(req->hdr.lrh[2]) << 2) -
653 			       (sizeof(tx->hdr) - 4));
654 	} else if (req_opcode(req->info.ctrl) == EXPECTED) {
655 		u32 tidlen = EXP_TID_GET(req->tids[req->tididx], LEN) *
656 			PAGE_SIZE;
657 		/*
658 		 * Get the data length based on the remaining space in the
659 		 * TID pair.
660 		 */
661 		len = min(tidlen - req->tidoffset, (u32)req->info.fragsize);
662 		/* If we've filled up the TID pair, move to the next one. */
663 		if (unlikely(!len) && ++req->tididx < req->n_tids &&
664 		    req->tids[req->tididx]) {
665 			tidlen = EXP_TID_GET(req->tids[req->tididx],
666 					     LEN) * PAGE_SIZE;
667 			req->tidoffset = 0;
668 			len = min_t(u32, tidlen, req->info.fragsize);
669 		}
670 		/*
671 		 * Since the TID pairs map entire pages, make sure that we
672 		 * are not going to try to send more data that we have
673 		 * remaining.
674 		 */
675 		len = min(len, req->data_len - req->sent);
676 	} else {
677 		len = min(req->data_len - req->sent, (u32)req->info.fragsize);
678 	}
679 	trace_hfi1_sdma_user_compute_length(req->pq->dd,
680 					    req->pq->ctxt,
681 					    req->pq->subctxt,
682 					    req->info.comp_idx,
683 					    len);
684 	return len;
685 }
686 
pad_len(u32 len)687 static inline u32 pad_len(u32 len)
688 {
689 	if (len & (sizeof(u32) - 1))
690 		len += sizeof(u32) - (len & (sizeof(u32) - 1));
691 	return len;
692 }
693 
get_lrh_len(struct hfi1_pkt_header hdr,u32 len)694 static inline u32 get_lrh_len(struct hfi1_pkt_header hdr, u32 len)
695 {
696 	/* (Size of complete header - size of PBC) + 4B ICRC + data length */
697 	return ((sizeof(hdr) - sizeof(hdr.pbc)) + 4 + len);
698 }
699 
user_sdma_txadd_ahg(struct user_sdma_request * req,struct user_sdma_txreq * tx,u32 datalen)700 static int user_sdma_txadd_ahg(struct user_sdma_request *req,
701 			       struct user_sdma_txreq *tx,
702 			       u32 datalen)
703 {
704 	int ret;
705 	u16 pbclen = le16_to_cpu(req->hdr.pbc[0]);
706 	u32 lrhlen = get_lrh_len(req->hdr, pad_len(datalen));
707 	struct hfi1_user_sdma_pkt_q *pq = req->pq;
708 
709 	/*
710 	 * Copy the request header into the tx header
711 	 * because the HW needs a cacheline-aligned
712 	 * address.
713 	 * This copy can be optimized out if the hdr
714 	 * member of user_sdma_request were also
715 	 * cacheline aligned.
716 	 */
717 	memcpy(&tx->hdr, &req->hdr, sizeof(tx->hdr));
718 	if (PBC2LRH(pbclen) != lrhlen) {
719 		pbclen = (pbclen & 0xf000) | LRH2PBC(lrhlen);
720 		tx->hdr.pbc[0] = cpu_to_le16(pbclen);
721 	}
722 	ret = check_header_template(req, &tx->hdr, lrhlen, datalen);
723 	if (ret)
724 		return ret;
725 	ret = sdma_txinit_ahg(&tx->txreq, SDMA_TXREQ_F_AHG_COPY,
726 			      sizeof(tx->hdr) + datalen, req->ahg_idx,
727 			      0, NULL, 0, user_sdma_txreq_cb);
728 	if (ret)
729 		return ret;
730 	ret = sdma_txadd_kvaddr(pq->dd, &tx->txreq, &tx->hdr, sizeof(tx->hdr));
731 	if (ret)
732 		sdma_txclean(pq->dd, &tx->txreq);
733 	return ret;
734 }
735 
user_sdma_send_pkts(struct user_sdma_request * req,u16 maxpkts)736 static int user_sdma_send_pkts(struct user_sdma_request *req, u16 maxpkts)
737 {
738 	int ret = 0;
739 	u16 count;
740 	unsigned npkts = 0;
741 	struct user_sdma_txreq *tx = NULL;
742 	struct hfi1_user_sdma_pkt_q *pq = NULL;
743 	struct user_sdma_iovec *iovec = NULL;
744 
745 	if (!req->pq)
746 		return -EINVAL;
747 
748 	pq = req->pq;
749 
750 	/* If tx completion has reported an error, we are done. */
751 	if (READ_ONCE(req->has_error))
752 		return -EFAULT;
753 
754 	/*
755 	 * Check if we might have sent the entire request already
756 	 */
757 	if (unlikely(req->seqnum == req->info.npkts)) {
758 		if (!list_empty(&req->txps))
759 			goto dosend;
760 		return ret;
761 	}
762 
763 	if (!maxpkts || maxpkts > req->info.npkts - req->seqnum)
764 		maxpkts = req->info.npkts - req->seqnum;
765 
766 	while (npkts < maxpkts) {
767 		u32 datalen = 0;
768 
769 		/*
770 		 * Check whether any of the completions have come back
771 		 * with errors. If so, we are not going to process any
772 		 * more packets from this request.
773 		 */
774 		if (READ_ONCE(req->has_error))
775 			return -EFAULT;
776 
777 		tx = kmem_cache_alloc(pq->txreq_cache, GFP_KERNEL);
778 		if (!tx)
779 			return -ENOMEM;
780 
781 		tx->flags = 0;
782 		tx->req = req;
783 		INIT_LIST_HEAD(&tx->list);
784 
785 		/*
786 		 * For the last packet set the ACK request
787 		 * and disable header suppression.
788 		 */
789 		if (req->seqnum == req->info.npkts - 1)
790 			tx->flags |= (TXREQ_FLAGS_REQ_ACK |
791 				      TXREQ_FLAGS_REQ_DISABLE_SH);
792 
793 		/*
794 		 * Calculate the payload size - this is min of the fragment
795 		 * (MTU) size or the remaining bytes in the request but only
796 		 * if we have payload data.
797 		 */
798 		if (req->data_len) {
799 			iovec = &req->iovs[req->iov_idx];
800 			if (READ_ONCE(iovec->offset) == iovec->iov.iov_len) {
801 				if (++req->iov_idx == req->data_iovs) {
802 					ret = -EFAULT;
803 					goto free_tx;
804 				}
805 				iovec = &req->iovs[req->iov_idx];
806 				WARN_ON(iovec->offset);
807 			}
808 
809 			datalen = compute_data_length(req, tx);
810 
811 			/*
812 			 * Disable header suppression for the payload <= 8DWS.
813 			 * If there is an uncorrectable error in the receive
814 			 * data FIFO when the received payload size is less than
815 			 * or equal to 8DWS then the RxDmaDataFifoRdUncErr is
816 			 * not reported.There is set RHF.EccErr if the header
817 			 * is not suppressed.
818 			 */
819 			if (!datalen) {
820 				SDMA_DBG(req,
821 					 "Request has data but pkt len is 0");
822 				ret = -EFAULT;
823 				goto free_tx;
824 			} else if (datalen <= 32) {
825 				tx->flags |= TXREQ_FLAGS_REQ_DISABLE_SH;
826 			}
827 		}
828 
829 		if (req->ahg_idx >= 0) {
830 			if (!req->seqnum) {
831 				ret = user_sdma_txadd_ahg(req, tx, datalen);
832 				if (ret)
833 					goto free_tx;
834 			} else {
835 				int changes;
836 
837 				changes = set_txreq_header_ahg(req, tx,
838 							       datalen);
839 				if (changes < 0) {
840 					ret = changes;
841 					goto free_tx;
842 				}
843 			}
844 		} else {
845 			ret = sdma_txinit(&tx->txreq, 0, sizeof(req->hdr) +
846 					  datalen, user_sdma_txreq_cb);
847 			if (ret)
848 				goto free_tx;
849 			/*
850 			 * Modify the header for this packet. This only needs
851 			 * to be done if we are not going to use AHG. Otherwise,
852 			 * the HW will do it based on the changes we gave it
853 			 * during sdma_txinit_ahg().
854 			 */
855 			ret = set_txreq_header(req, tx, datalen);
856 			if (ret)
857 				goto free_txreq;
858 		}
859 
860 		req->koffset += datalen;
861 		if (req_opcode(req->info.ctrl) == EXPECTED)
862 			req->tidoffset += datalen;
863 		req->sent += datalen;
864 		while (datalen) {
865 			ret = add_system_pages_to_sdma_packet(req, tx, iovec,
866 							      &datalen);
867 			if (ret)
868 				goto free_txreq;
869 			iovec = &req->iovs[req->iov_idx];
870 		}
871 		list_add_tail(&tx->txreq.list, &req->txps);
872 		/*
873 		 * It is important to increment this here as it is used to
874 		 * generate the BTH.PSN and, therefore, can't be bulk-updated
875 		 * outside of the loop.
876 		 */
877 		tx->seqnum = req->seqnum++;
878 		npkts++;
879 	}
880 dosend:
881 	ret = sdma_send_txlist(req->sde,
882 			       iowait_get_ib_work(&pq->busy),
883 			       &req->txps, &count);
884 	req->seqsubmitted += count;
885 	if (req->seqsubmitted == req->info.npkts) {
886 		/*
887 		 * The txreq has already been submitted to the HW queue
888 		 * so we can free the AHG entry now. Corruption will not
889 		 * happen due to the sequential manner in which
890 		 * descriptors are processed.
891 		 */
892 		if (req->ahg_idx >= 0)
893 			sdma_ahg_free(req->sde, req->ahg_idx);
894 	}
895 	return ret;
896 
897 free_txreq:
898 	sdma_txclean(pq->dd, &tx->txreq);
899 free_tx:
900 	kmem_cache_free(pq->txreq_cache, tx);
901 	return ret;
902 }
903 
sdma_cache_evict(struct hfi1_user_sdma_pkt_q * pq,u32 npages)904 static u32 sdma_cache_evict(struct hfi1_user_sdma_pkt_q *pq, u32 npages)
905 {
906 	struct evict_data evict_data;
907 	struct mmu_rb_handler *handler = pq->handler;
908 
909 	evict_data.cleared = 0;
910 	evict_data.target = npages;
911 	hfi1_mmu_rb_evict(handler, &evict_data);
912 	return evict_data.cleared;
913 }
914 
check_header_template(struct user_sdma_request * req,struct hfi1_pkt_header * hdr,u32 lrhlen,u32 datalen)915 static int check_header_template(struct user_sdma_request *req,
916 				 struct hfi1_pkt_header *hdr, u32 lrhlen,
917 				 u32 datalen)
918 {
919 	/*
920 	 * Perform safety checks for any type of packet:
921 	 *    - transfer size is multiple of 64bytes
922 	 *    - packet length is multiple of 4 bytes
923 	 *    - packet length is not larger than MTU size
924 	 *
925 	 * These checks are only done for the first packet of the
926 	 * transfer since the header is "given" to us by user space.
927 	 * For the remainder of the packets we compute the values.
928 	 */
929 	if (req->info.fragsize % PIO_BLOCK_SIZE || lrhlen & 0x3 ||
930 	    lrhlen > get_lrh_len(*hdr, req->info.fragsize))
931 		return -EINVAL;
932 
933 	if (req_opcode(req->info.ctrl) == EXPECTED) {
934 		/*
935 		 * The header is checked only on the first packet. Furthermore,
936 		 * we ensure that at least one TID entry is copied when the
937 		 * request is submitted. Therefore, we don't have to verify that
938 		 * tididx points to something sane.
939 		 */
940 		u32 tidval = req->tids[req->tididx],
941 			tidlen = EXP_TID_GET(tidval, LEN) * PAGE_SIZE,
942 			tididx = EXP_TID_GET(tidval, IDX),
943 			tidctrl = EXP_TID_GET(tidval, CTRL),
944 			tidoff;
945 		__le32 kval = hdr->kdeth.ver_tid_offset;
946 
947 		tidoff = KDETH_GET(kval, OFFSET) *
948 			  (KDETH_GET(req->hdr.kdeth.ver_tid_offset, OM) ?
949 			   KDETH_OM_LARGE : KDETH_OM_SMALL);
950 		/*
951 		 * Expected receive packets have the following
952 		 * additional checks:
953 		 *     - offset is not larger than the TID size
954 		 *     - TIDCtrl values match between header and TID array
955 		 *     - TID indexes match between header and TID array
956 		 */
957 		if ((tidoff + datalen > tidlen) ||
958 		    KDETH_GET(kval, TIDCTRL) != tidctrl ||
959 		    KDETH_GET(kval, TID) != tididx)
960 			return -EINVAL;
961 	}
962 	return 0;
963 }
964 
965 /*
966  * Correctly set the BTH.PSN field based on type of
967  * transfer - eager packets can just increment the PSN but
968  * expected packets encode generation and sequence in the
969  * BTH.PSN field so just incrementing will result in errors.
970  */
set_pkt_bth_psn(__be32 bthpsn,u8 expct,u32 frags)971 static inline u32 set_pkt_bth_psn(__be32 bthpsn, u8 expct, u32 frags)
972 {
973 	u32 val = be32_to_cpu(bthpsn),
974 		mask = (HFI1_CAP_IS_KSET(EXTENDED_PSN) ? 0x7fffffffull :
975 			0xffffffull),
976 		psn = val & mask;
977 	if (expct)
978 		psn = (psn & ~HFI1_KDETH_BTH_SEQ_MASK) |
979 			((psn + frags) & HFI1_KDETH_BTH_SEQ_MASK);
980 	else
981 		psn = psn + frags;
982 	return psn & mask;
983 }
984 
set_txreq_header(struct user_sdma_request * req,struct user_sdma_txreq * tx,u32 datalen)985 static int set_txreq_header(struct user_sdma_request *req,
986 			    struct user_sdma_txreq *tx, u32 datalen)
987 {
988 	struct hfi1_user_sdma_pkt_q *pq = req->pq;
989 	struct hfi1_pkt_header *hdr = &tx->hdr;
990 	u8 omfactor; /* KDETH.OM */
991 	u16 pbclen;
992 	int ret;
993 	u32 tidval = 0, lrhlen = get_lrh_len(*hdr, pad_len(datalen));
994 
995 	/* Copy the header template to the request before modification */
996 	memcpy(hdr, &req->hdr, sizeof(*hdr));
997 
998 	/*
999 	 * Check if the PBC and LRH length are mismatched. If so
1000 	 * adjust both in the header.
1001 	 */
1002 	pbclen = le16_to_cpu(hdr->pbc[0]);
1003 	if (PBC2LRH(pbclen) != lrhlen) {
1004 		pbclen = (pbclen & 0xf000) | LRH2PBC(lrhlen);
1005 		hdr->pbc[0] = cpu_to_le16(pbclen);
1006 		hdr->lrh[2] = cpu_to_be16(lrhlen >> 2);
1007 		/*
1008 		 * Third packet
1009 		 * This is the first packet in the sequence that has
1010 		 * a "static" size that can be used for the rest of
1011 		 * the packets (besides the last one).
1012 		 */
1013 		if (unlikely(req->seqnum == 2)) {
1014 			/*
1015 			 * From this point on the lengths in both the
1016 			 * PBC and LRH are the same until the last
1017 			 * packet.
1018 			 * Adjust the template so we don't have to update
1019 			 * every packet
1020 			 */
1021 			req->hdr.pbc[0] = hdr->pbc[0];
1022 			req->hdr.lrh[2] = hdr->lrh[2];
1023 		}
1024 	}
1025 	/*
1026 	 * We only have to modify the header if this is not the
1027 	 * first packet in the request. Otherwise, we use the
1028 	 * header given to us.
1029 	 */
1030 	if (unlikely(!req->seqnum)) {
1031 		ret = check_header_template(req, hdr, lrhlen, datalen);
1032 		if (ret)
1033 			return ret;
1034 		goto done;
1035 	}
1036 
1037 	hdr->bth[2] = cpu_to_be32(
1038 		set_pkt_bth_psn(hdr->bth[2],
1039 				(req_opcode(req->info.ctrl) == EXPECTED),
1040 				req->seqnum));
1041 
1042 	/* Set ACK request on last packet */
1043 	if (unlikely(tx->flags & TXREQ_FLAGS_REQ_ACK))
1044 		hdr->bth[2] |= cpu_to_be32(1UL << 31);
1045 
1046 	/* Set the new offset */
1047 	hdr->kdeth.swdata[6] = cpu_to_le32(req->koffset);
1048 	/* Expected packets have to fill in the new TID information */
1049 	if (req_opcode(req->info.ctrl) == EXPECTED) {
1050 		tidval = req->tids[req->tididx];
1051 		/*
1052 		 * If the offset puts us at the end of the current TID,
1053 		 * advance everything.
1054 		 */
1055 		if ((req->tidoffset) == (EXP_TID_GET(tidval, LEN) *
1056 					 PAGE_SIZE)) {
1057 			req->tidoffset = 0;
1058 			/*
1059 			 * Since we don't copy all the TIDs, all at once,
1060 			 * we have to check again.
1061 			 */
1062 			if (++req->tididx > req->n_tids - 1 ||
1063 			    !req->tids[req->tididx]) {
1064 				return -EINVAL;
1065 			}
1066 			tidval = req->tids[req->tididx];
1067 		}
1068 		omfactor = EXP_TID_GET(tidval, LEN) * PAGE_SIZE >=
1069 			KDETH_OM_MAX_SIZE ? KDETH_OM_LARGE_SHIFT :
1070 			KDETH_OM_SMALL_SHIFT;
1071 		/* Set KDETH.TIDCtrl based on value for this TID. */
1072 		KDETH_SET(hdr->kdeth.ver_tid_offset, TIDCTRL,
1073 			  EXP_TID_GET(tidval, CTRL));
1074 		/* Set KDETH.TID based on value for this TID */
1075 		KDETH_SET(hdr->kdeth.ver_tid_offset, TID,
1076 			  EXP_TID_GET(tidval, IDX));
1077 		/* Clear KDETH.SH when DISABLE_SH flag is set */
1078 		if (unlikely(tx->flags & TXREQ_FLAGS_REQ_DISABLE_SH))
1079 			KDETH_SET(hdr->kdeth.ver_tid_offset, SH, 0);
1080 		/*
1081 		 * Set the KDETH.OFFSET and KDETH.OM based on size of
1082 		 * transfer.
1083 		 */
1084 		trace_hfi1_sdma_user_tid_info(
1085 			pq->dd, pq->ctxt, pq->subctxt, req->info.comp_idx,
1086 			req->tidoffset, req->tidoffset >> omfactor,
1087 			omfactor != KDETH_OM_SMALL_SHIFT);
1088 		KDETH_SET(hdr->kdeth.ver_tid_offset, OFFSET,
1089 			  req->tidoffset >> omfactor);
1090 		KDETH_SET(hdr->kdeth.ver_tid_offset, OM,
1091 			  omfactor != KDETH_OM_SMALL_SHIFT);
1092 	}
1093 done:
1094 	trace_hfi1_sdma_user_header(pq->dd, pq->ctxt, pq->subctxt,
1095 				    req->info.comp_idx, hdr, tidval);
1096 	return sdma_txadd_kvaddr(pq->dd, &tx->txreq, hdr, sizeof(*hdr));
1097 }
1098 
set_txreq_header_ahg(struct user_sdma_request * req,struct user_sdma_txreq * tx,u32 datalen)1099 static int set_txreq_header_ahg(struct user_sdma_request *req,
1100 				struct user_sdma_txreq *tx, u32 datalen)
1101 {
1102 	u32 ahg[AHG_KDETH_ARRAY_SIZE];
1103 	int idx = 0;
1104 	u8 omfactor; /* KDETH.OM */
1105 	struct hfi1_user_sdma_pkt_q *pq = req->pq;
1106 	struct hfi1_pkt_header *hdr = &req->hdr;
1107 	u16 pbclen = le16_to_cpu(hdr->pbc[0]);
1108 	u32 val32, tidval = 0, lrhlen = get_lrh_len(*hdr, pad_len(datalen));
1109 	size_t array_size = ARRAY_SIZE(ahg);
1110 
1111 	if (PBC2LRH(pbclen) != lrhlen) {
1112 		/* PBC.PbcLengthDWs */
1113 		idx = ahg_header_set(ahg, idx, array_size, 0, 0, 12,
1114 				     (__force u16)cpu_to_le16(LRH2PBC(lrhlen)));
1115 		if (idx < 0)
1116 			return idx;
1117 		/* LRH.PktLen (we need the full 16 bits due to byte swap) */
1118 		idx = ahg_header_set(ahg, idx, array_size, 3, 0, 16,
1119 				     (__force u16)cpu_to_be16(lrhlen >> 2));
1120 		if (idx < 0)
1121 			return idx;
1122 	}
1123 
1124 	/*
1125 	 * Do the common updates
1126 	 */
1127 	/* BTH.PSN and BTH.A */
1128 	val32 = (be32_to_cpu(hdr->bth[2]) + req->seqnum) &
1129 		(HFI1_CAP_IS_KSET(EXTENDED_PSN) ? 0x7fffffff : 0xffffff);
1130 	if (unlikely(tx->flags & TXREQ_FLAGS_REQ_ACK))
1131 		val32 |= 1UL << 31;
1132 	idx = ahg_header_set(ahg, idx, array_size, 6, 0, 16,
1133 			     (__force u16)cpu_to_be16(val32 >> 16));
1134 	if (idx < 0)
1135 		return idx;
1136 	idx = ahg_header_set(ahg, idx, array_size, 6, 16, 16,
1137 			     (__force u16)cpu_to_be16(val32 & 0xffff));
1138 	if (idx < 0)
1139 		return idx;
1140 	/* KDETH.Offset */
1141 	idx = ahg_header_set(ahg, idx, array_size, 15, 0, 16,
1142 			     (__force u16)cpu_to_le16(req->koffset & 0xffff));
1143 	if (idx < 0)
1144 		return idx;
1145 	idx = ahg_header_set(ahg, idx, array_size, 15, 16, 16,
1146 			     (__force u16)cpu_to_le16(req->koffset >> 16));
1147 	if (idx < 0)
1148 		return idx;
1149 	if (req_opcode(req->info.ctrl) == EXPECTED) {
1150 		__le16 val;
1151 
1152 		tidval = req->tids[req->tididx];
1153 
1154 		/*
1155 		 * If the offset puts us at the end of the current TID,
1156 		 * advance everything.
1157 		 */
1158 		if ((req->tidoffset) == (EXP_TID_GET(tidval, LEN) *
1159 					 PAGE_SIZE)) {
1160 			req->tidoffset = 0;
1161 			/*
1162 			 * Since we don't copy all the TIDs, all at once,
1163 			 * we have to check again.
1164 			 */
1165 			if (++req->tididx > req->n_tids - 1 ||
1166 			    !req->tids[req->tididx])
1167 				return -EINVAL;
1168 			tidval = req->tids[req->tididx];
1169 		}
1170 		omfactor = ((EXP_TID_GET(tidval, LEN) *
1171 				  PAGE_SIZE) >=
1172 				 KDETH_OM_MAX_SIZE) ? KDETH_OM_LARGE_SHIFT :
1173 				 KDETH_OM_SMALL_SHIFT;
1174 		/* KDETH.OM and KDETH.OFFSET (TID) */
1175 		idx = ahg_header_set(
1176 				ahg, idx, array_size, 7, 0, 16,
1177 				((!!(omfactor - KDETH_OM_SMALL_SHIFT)) << 15 |
1178 				((req->tidoffset >> omfactor)
1179 				& 0x7fff)));
1180 		if (idx < 0)
1181 			return idx;
1182 		/* KDETH.TIDCtrl, KDETH.TID, KDETH.Intr, KDETH.SH */
1183 		val = cpu_to_le16(((EXP_TID_GET(tidval, CTRL) & 0x3) << 10) |
1184 				   (EXP_TID_GET(tidval, IDX) & 0x3ff));
1185 
1186 		if (unlikely(tx->flags & TXREQ_FLAGS_REQ_DISABLE_SH)) {
1187 			val |= cpu_to_le16((KDETH_GET(hdr->kdeth.ver_tid_offset,
1188 						      INTR) <<
1189 					    AHG_KDETH_INTR_SHIFT));
1190 		} else {
1191 			val |= KDETH_GET(hdr->kdeth.ver_tid_offset, SH) ?
1192 			       cpu_to_le16(0x1 << AHG_KDETH_SH_SHIFT) :
1193 			       cpu_to_le16((KDETH_GET(hdr->kdeth.ver_tid_offset,
1194 						      INTR) <<
1195 					     AHG_KDETH_INTR_SHIFT));
1196 		}
1197 
1198 		idx = ahg_header_set(ahg, idx, array_size,
1199 				     7, 16, 14, (__force u16)val);
1200 		if (idx < 0)
1201 			return idx;
1202 	}
1203 
1204 	trace_hfi1_sdma_user_header_ahg(pq->dd, pq->ctxt, pq->subctxt,
1205 					req->info.comp_idx, req->sde->this_idx,
1206 					req->ahg_idx, ahg, idx, tidval);
1207 	sdma_txinit_ahg(&tx->txreq,
1208 			SDMA_TXREQ_F_USE_AHG,
1209 			datalen, req->ahg_idx, idx,
1210 			ahg, sizeof(req->hdr),
1211 			user_sdma_txreq_cb);
1212 
1213 	return idx;
1214 }
1215 
1216 /**
1217  * user_sdma_txreq_cb() - SDMA tx request completion callback.
1218  * @txreq: valid sdma tx request
1219  * @status: success/failure of request
1220  *
1221  * Called when the SDMA progress state machine gets notification that
1222  * the SDMA descriptors for this tx request have been processed by the
1223  * DMA engine. Called in interrupt context.
1224  * Only do work on completed sequences.
1225  */
user_sdma_txreq_cb(struct sdma_txreq * txreq,int status)1226 static void user_sdma_txreq_cb(struct sdma_txreq *txreq, int status)
1227 {
1228 	struct user_sdma_txreq *tx =
1229 		container_of(txreq, struct user_sdma_txreq, txreq);
1230 	struct user_sdma_request *req;
1231 	struct hfi1_user_sdma_pkt_q *pq;
1232 	struct hfi1_user_sdma_comp_q *cq;
1233 	enum hfi1_sdma_comp_state state = COMPLETE;
1234 
1235 	if (!tx->req)
1236 		return;
1237 
1238 	req = tx->req;
1239 	pq = req->pq;
1240 	cq = req->cq;
1241 
1242 	if (status != SDMA_TXREQ_S_OK) {
1243 		SDMA_DBG(req, "SDMA completion with error %d",
1244 			 status);
1245 		WRITE_ONCE(req->has_error, 1);
1246 		state = ERROR;
1247 	}
1248 
1249 	req->seqcomp = tx->seqnum;
1250 	kmem_cache_free(pq->txreq_cache, tx);
1251 
1252 	/* sequence isn't complete?  We are done */
1253 	if (req->seqcomp != req->info.npkts - 1)
1254 		return;
1255 
1256 	user_sdma_free_request(req);
1257 	set_comp_state(pq, cq, req->info.comp_idx, state, status);
1258 	pq_update(pq);
1259 }
1260 
pq_update(struct hfi1_user_sdma_pkt_q * pq)1261 static inline void pq_update(struct hfi1_user_sdma_pkt_q *pq)
1262 {
1263 	if (atomic_dec_and_test(&pq->n_reqs))
1264 		wake_up(&pq->wait);
1265 }
1266 
user_sdma_free_request(struct user_sdma_request * req)1267 static void user_sdma_free_request(struct user_sdma_request *req)
1268 {
1269 	if (!list_empty(&req->txps)) {
1270 		struct sdma_txreq *t, *p;
1271 
1272 		list_for_each_entry_safe(t, p, &req->txps, list) {
1273 			struct user_sdma_txreq *tx =
1274 				container_of(t, struct user_sdma_txreq, txreq);
1275 			list_del_init(&t->list);
1276 			sdma_txclean(req->pq->dd, t);
1277 			kmem_cache_free(req->pq->txreq_cache, tx);
1278 		}
1279 	}
1280 
1281 	kfree(req->tids);
1282 	clear_bit(req->info.comp_idx, req->pq->req_in_use);
1283 }
1284 
set_comp_state(struct hfi1_user_sdma_pkt_q * pq,struct hfi1_user_sdma_comp_q * cq,u16 idx,enum hfi1_sdma_comp_state state,int ret)1285 static inline void set_comp_state(struct hfi1_user_sdma_pkt_q *pq,
1286 				  struct hfi1_user_sdma_comp_q *cq,
1287 				  u16 idx, enum hfi1_sdma_comp_state state,
1288 				  int ret)
1289 {
1290 	if (state == ERROR)
1291 		cq->comps[idx].errcode = -ret;
1292 	smp_wmb(); /* make sure errcode is visible first */
1293 	cq->comps[idx].status = state;
1294 	trace_hfi1_sdma_user_completion(pq->dd, pq->ctxt, pq->subctxt,
1295 					idx, state, ret);
1296 }
1297 
unpin_vector_pages(struct mm_struct * mm,struct page ** pages,unsigned int start,unsigned int npages)1298 static void unpin_vector_pages(struct mm_struct *mm, struct page **pages,
1299 			       unsigned int start, unsigned int npages)
1300 {
1301 	hfi1_release_user_pages(mm, pages + start, npages, false);
1302 	kfree(pages);
1303 }
1304 
free_system_node(struct sdma_mmu_node * node)1305 static void free_system_node(struct sdma_mmu_node *node)
1306 {
1307 	if (node->npages) {
1308 		unpin_vector_pages(mm_from_sdma_node(node), node->pages, 0,
1309 				   node->npages);
1310 		atomic_sub(node->npages, &node->pq->n_locked);
1311 	}
1312 	kfree(node);
1313 }
1314 
1315 /*
1316  * kref_get()'s an additional kref on the returned rb_node to prevent rb_node
1317  * from being released until after rb_node is assigned to an SDMA descriptor
1318  * (struct sdma_desc) under add_system_iovec_to_sdma_packet(), even if the
1319  * virtual address range for rb_node is invalidated between now and then.
1320  */
find_system_node(struct mmu_rb_handler * handler,unsigned long start,unsigned long end)1321 static struct sdma_mmu_node *find_system_node(struct mmu_rb_handler *handler,
1322 					      unsigned long start,
1323 					      unsigned long end)
1324 {
1325 	struct mmu_rb_node *rb_node;
1326 	unsigned long flags;
1327 
1328 	spin_lock_irqsave(&handler->lock, flags);
1329 	rb_node = hfi1_mmu_rb_get_first(handler, start, (end - start));
1330 	if (!rb_node) {
1331 		spin_unlock_irqrestore(&handler->lock, flags);
1332 		return NULL;
1333 	}
1334 
1335 	/* "safety" kref to prevent release before add_system_iovec_to_sdma_packet() */
1336 	kref_get(&rb_node->refcount);
1337 	spin_unlock_irqrestore(&handler->lock, flags);
1338 
1339 	return container_of(rb_node, struct sdma_mmu_node, rb);
1340 }
1341 
pin_system_pages(struct user_sdma_request * req,uintptr_t start_address,size_t length,struct sdma_mmu_node * node,int npages)1342 static int pin_system_pages(struct user_sdma_request *req,
1343 			    uintptr_t start_address, size_t length,
1344 			    struct sdma_mmu_node *node, int npages)
1345 {
1346 	struct hfi1_user_sdma_pkt_q *pq = req->pq;
1347 	int pinned, cleared;
1348 	struct page **pages;
1349 
1350 	pages = kcalloc(npages, sizeof(*pages), GFP_KERNEL);
1351 	if (!pages)
1352 		return -ENOMEM;
1353 
1354 retry:
1355 	if (!hfi1_can_pin_pages(pq->dd, current->mm, atomic_read(&pq->n_locked),
1356 				npages)) {
1357 		SDMA_DBG(req, "Evicting: nlocked %u npages %u",
1358 			 atomic_read(&pq->n_locked), npages);
1359 		cleared = sdma_cache_evict(pq, npages);
1360 		if (cleared >= npages)
1361 			goto retry;
1362 	}
1363 
1364 	SDMA_DBG(req, "Acquire user pages start_address %lx node->npages %u npages %u",
1365 		 start_address, node->npages, npages);
1366 	pinned = hfi1_acquire_user_pages(current->mm, start_address, npages, 0,
1367 					 pages);
1368 
1369 	if (pinned < 0) {
1370 		kfree(pages);
1371 		SDMA_DBG(req, "pinned %d", pinned);
1372 		return pinned;
1373 	}
1374 	if (pinned != npages) {
1375 		unpin_vector_pages(current->mm, pages, node->npages, pinned);
1376 		SDMA_DBG(req, "npages %u pinned %d", npages, pinned);
1377 		return -EFAULT;
1378 	}
1379 	node->rb.addr = start_address;
1380 	node->rb.len = length;
1381 	node->pages = pages;
1382 	node->npages = npages;
1383 	atomic_add(pinned, &pq->n_locked);
1384 	SDMA_DBG(req, "done. pinned %d", pinned);
1385 	return 0;
1386 }
1387 
1388 /*
1389  * kref refcount on *node_p will be 2 on successful addition: one kref from
1390  * kref_init() for mmu_rb_handler and one kref to prevent *node_p from being
1391  * released until after *node_p is assigned to an SDMA descriptor (struct
1392  * sdma_desc) under add_system_iovec_to_sdma_packet(), even if the virtual
1393  * address range for *node_p is invalidated between now and then.
1394  */
add_system_pinning(struct user_sdma_request * req,struct sdma_mmu_node ** node_p,unsigned long start,unsigned long len)1395 static int add_system_pinning(struct user_sdma_request *req,
1396 			      struct sdma_mmu_node **node_p,
1397 			      unsigned long start, unsigned long len)
1398 
1399 {
1400 	struct hfi1_user_sdma_pkt_q *pq = req->pq;
1401 	struct sdma_mmu_node *node;
1402 	int ret;
1403 
1404 	node = kzalloc(sizeof(*node), GFP_KERNEL);
1405 	if (!node)
1406 		return -ENOMEM;
1407 
1408 	/* First kref "moves" to mmu_rb_handler */
1409 	kref_init(&node->rb.refcount);
1410 
1411 	/* "safety" kref to prevent release before add_system_iovec_to_sdma_packet() */
1412 	kref_get(&node->rb.refcount);
1413 
1414 	node->pq = pq;
1415 	ret = pin_system_pages(req, start, len, node, PFN_DOWN(len));
1416 	if (ret == 0) {
1417 		ret = hfi1_mmu_rb_insert(pq->handler, &node->rb);
1418 		if (ret)
1419 			free_system_node(node);
1420 		else
1421 			*node_p = node;
1422 
1423 		return ret;
1424 	}
1425 
1426 	kfree(node);
1427 	return ret;
1428 }
1429 
get_system_cache_entry(struct user_sdma_request * req,struct sdma_mmu_node ** node_p,size_t req_start,size_t req_len)1430 static int get_system_cache_entry(struct user_sdma_request *req,
1431 				  struct sdma_mmu_node **node_p,
1432 				  size_t req_start, size_t req_len)
1433 {
1434 	struct hfi1_user_sdma_pkt_q *pq = req->pq;
1435 	u64 start = ALIGN_DOWN(req_start, PAGE_SIZE);
1436 	u64 end = PFN_ALIGN(req_start + req_len);
1437 	struct mmu_rb_handler *handler = pq->handler;
1438 	int ret;
1439 
1440 	if ((end - start) == 0) {
1441 		SDMA_DBG(req,
1442 			 "Request for empty cache entry req_start %lx req_len %lx start %llx end %llx",
1443 			 req_start, req_len, start, end);
1444 		return -EINVAL;
1445 	}
1446 
1447 	SDMA_DBG(req, "req_start %lx req_len %lu", req_start, req_len);
1448 
1449 	while (1) {
1450 		struct sdma_mmu_node *node =
1451 			find_system_node(handler, start, end);
1452 		u64 prepend_len = 0;
1453 
1454 		SDMA_DBG(req, "node %p start %llx end %llu", node, start, end);
1455 		if (!node) {
1456 			ret = add_system_pinning(req, node_p, start,
1457 						 end - start);
1458 			if (ret == -EEXIST) {
1459 				/*
1460 				 * Another execution context has inserted a
1461 				 * conficting entry first.
1462 				 */
1463 				continue;
1464 			}
1465 			return ret;
1466 		}
1467 
1468 		if (node->rb.addr <= start) {
1469 			/*
1470 			 * This entry covers at least part of the region. If it doesn't extend
1471 			 * to the end, then this will be called again for the next segment.
1472 			 */
1473 			*node_p = node;
1474 			return 0;
1475 		}
1476 
1477 		SDMA_DBG(req, "prepend: node->rb.addr %lx, node->rb.refcount %d",
1478 			 node->rb.addr, kref_read(&node->rb.refcount));
1479 		prepend_len = node->rb.addr - start;
1480 
1481 		/*
1482 		 * This node will not be returned, instead a new node
1483 		 * will be. So release the reference.
1484 		 */
1485 		kref_put(&node->rb.refcount, hfi1_mmu_rb_release);
1486 
1487 		/* Prepend a node to cover the beginning of the allocation */
1488 		ret = add_system_pinning(req, node_p, start, prepend_len);
1489 		if (ret == -EEXIST) {
1490 			/* Another execution context has inserted a conficting entry first. */
1491 			continue;
1492 		}
1493 		return ret;
1494 	}
1495 }
1496 
sdma_mmu_rb_node_get(void * ctx)1497 static void sdma_mmu_rb_node_get(void *ctx)
1498 {
1499 	struct mmu_rb_node *node = ctx;
1500 
1501 	kref_get(&node->refcount);
1502 }
1503 
sdma_mmu_rb_node_put(void * ctx)1504 static void sdma_mmu_rb_node_put(void *ctx)
1505 {
1506 	struct sdma_mmu_node *node = ctx;
1507 
1508 	kref_put(&node->rb.refcount, hfi1_mmu_rb_release);
1509 }
1510 
add_mapping_to_sdma_packet(struct user_sdma_request * req,struct user_sdma_txreq * tx,struct sdma_mmu_node * cache_entry,size_t start,size_t from_this_cache_entry)1511 static int add_mapping_to_sdma_packet(struct user_sdma_request *req,
1512 				      struct user_sdma_txreq *tx,
1513 				      struct sdma_mmu_node *cache_entry,
1514 				      size_t start,
1515 				      size_t from_this_cache_entry)
1516 {
1517 	struct hfi1_user_sdma_pkt_q *pq = req->pq;
1518 	unsigned int page_offset;
1519 	unsigned int from_this_page;
1520 	size_t page_index;
1521 	void *ctx;
1522 	int ret;
1523 
1524 	/*
1525 	 * Because the cache may be more fragmented than the memory that is being accessed,
1526 	 * it's not strictly necessary to have a descriptor per cache entry.
1527 	 */
1528 
1529 	while (from_this_cache_entry) {
1530 		page_index = PFN_DOWN(start - cache_entry->rb.addr);
1531 
1532 		if (page_index >= cache_entry->npages) {
1533 			SDMA_DBG(req,
1534 				 "Request for page_index %zu >= cache_entry->npages %u",
1535 				 page_index, cache_entry->npages);
1536 			return -EINVAL;
1537 		}
1538 
1539 		page_offset = start - ALIGN_DOWN(start, PAGE_SIZE);
1540 		from_this_page = PAGE_SIZE - page_offset;
1541 
1542 		if (from_this_page < from_this_cache_entry) {
1543 			ctx = NULL;
1544 		} else {
1545 			/*
1546 			 * In the case they are equal the next line has no practical effect,
1547 			 * but it's better to do a register to register copy than a conditional
1548 			 * branch.
1549 			 */
1550 			from_this_page = from_this_cache_entry;
1551 			ctx = cache_entry;
1552 		}
1553 
1554 		ret = sdma_txadd_page(pq->dd, &tx->txreq,
1555 				      cache_entry->pages[page_index],
1556 				      page_offset, from_this_page,
1557 				      ctx,
1558 				      sdma_mmu_rb_node_get,
1559 				      sdma_mmu_rb_node_put);
1560 		if (ret) {
1561 			/*
1562 			 * When there's a failure, the entire request is freed by
1563 			 * user_sdma_send_pkts().
1564 			 */
1565 			SDMA_DBG(req,
1566 				 "sdma_txadd_page failed %d page_index %lu page_offset %u from_this_page %u",
1567 				 ret, page_index, page_offset, from_this_page);
1568 			return ret;
1569 		}
1570 		start += from_this_page;
1571 		from_this_cache_entry -= from_this_page;
1572 	}
1573 	return 0;
1574 }
1575 
add_system_iovec_to_sdma_packet(struct user_sdma_request * req,struct user_sdma_txreq * tx,struct user_sdma_iovec * iovec,size_t from_this_iovec)1576 static int add_system_iovec_to_sdma_packet(struct user_sdma_request *req,
1577 					   struct user_sdma_txreq *tx,
1578 					   struct user_sdma_iovec *iovec,
1579 					   size_t from_this_iovec)
1580 {
1581 	while (from_this_iovec > 0) {
1582 		struct sdma_mmu_node *cache_entry;
1583 		size_t from_this_cache_entry;
1584 		size_t start;
1585 		int ret;
1586 
1587 		start = (uintptr_t)iovec->iov.iov_base + iovec->offset;
1588 		ret = get_system_cache_entry(req, &cache_entry, start,
1589 					     from_this_iovec);
1590 		if (ret) {
1591 			SDMA_DBG(req, "pin system segment failed %d", ret);
1592 			return ret;
1593 		}
1594 
1595 		from_this_cache_entry = cache_entry->rb.len - (start - cache_entry->rb.addr);
1596 		if (from_this_cache_entry > from_this_iovec)
1597 			from_this_cache_entry = from_this_iovec;
1598 
1599 		ret = add_mapping_to_sdma_packet(req, tx, cache_entry, start,
1600 						 from_this_cache_entry);
1601 
1602 		/*
1603 		 * Done adding cache_entry to zero or more sdma_desc. Can
1604 		 * kref_put() the "safety" kref taken under
1605 		 * get_system_cache_entry().
1606 		 */
1607 		kref_put(&cache_entry->rb.refcount, hfi1_mmu_rb_release);
1608 
1609 		if (ret) {
1610 			SDMA_DBG(req, "add system segment failed %d", ret);
1611 			return ret;
1612 		}
1613 
1614 		iovec->offset += from_this_cache_entry;
1615 		from_this_iovec -= from_this_cache_entry;
1616 	}
1617 
1618 	return 0;
1619 }
1620 
add_system_pages_to_sdma_packet(struct user_sdma_request * req,struct user_sdma_txreq * tx,struct user_sdma_iovec * iovec,u32 * pkt_data_remaining)1621 static int add_system_pages_to_sdma_packet(struct user_sdma_request *req,
1622 					   struct user_sdma_txreq *tx,
1623 					   struct user_sdma_iovec *iovec,
1624 					   u32 *pkt_data_remaining)
1625 {
1626 	size_t remaining_to_add = *pkt_data_remaining;
1627 	/*
1628 	 * Walk through iovec entries, ensure the associated pages
1629 	 * are pinned and mapped, add data to the packet until no more
1630 	 * data remains to be added.
1631 	 */
1632 	while (remaining_to_add > 0) {
1633 		struct user_sdma_iovec *cur_iovec;
1634 		size_t from_this_iovec;
1635 		int ret;
1636 
1637 		cur_iovec = iovec;
1638 		from_this_iovec = iovec->iov.iov_len - iovec->offset;
1639 
1640 		if (from_this_iovec > remaining_to_add) {
1641 			from_this_iovec = remaining_to_add;
1642 		} else {
1643 			/* The current iovec entry will be consumed by this pass. */
1644 			req->iov_idx++;
1645 			iovec++;
1646 		}
1647 
1648 		ret = add_system_iovec_to_sdma_packet(req, tx, cur_iovec,
1649 						      from_this_iovec);
1650 		if (ret)
1651 			return ret;
1652 
1653 		remaining_to_add -= from_this_iovec;
1654 	}
1655 	*pkt_data_remaining = remaining_to_add;
1656 
1657 	return 0;
1658 }
1659 
sdma_rb_filter(struct mmu_rb_node * node,unsigned long addr,unsigned long len)1660 static bool sdma_rb_filter(struct mmu_rb_node *node, unsigned long addr,
1661 			   unsigned long len)
1662 {
1663 	return (bool)(node->addr == addr);
1664 }
1665 
1666 /*
1667  * Return 1 to remove the node from the rb tree and call the remove op.
1668  *
1669  * Called with the rb tree lock held.
1670  */
sdma_rb_evict(void * arg,struct mmu_rb_node * mnode,void * evict_arg,bool * stop)1671 static int sdma_rb_evict(void *arg, struct mmu_rb_node *mnode,
1672 			 void *evict_arg, bool *stop)
1673 {
1674 	struct sdma_mmu_node *node =
1675 		container_of(mnode, struct sdma_mmu_node, rb);
1676 	struct evict_data *evict_data = evict_arg;
1677 
1678 	/* this node will be evicted, add its pages to our count */
1679 	evict_data->cleared += node->npages;
1680 
1681 	/* have enough pages been cleared? */
1682 	if (evict_data->cleared >= evict_data->target)
1683 		*stop = true;
1684 
1685 	return 1; /* remove this node */
1686 }
1687 
sdma_rb_remove(void * arg,struct mmu_rb_node * mnode)1688 static void sdma_rb_remove(void *arg, struct mmu_rb_node *mnode)
1689 {
1690 	struct sdma_mmu_node *node =
1691 		container_of(mnode, struct sdma_mmu_node, rb);
1692 
1693 	free_system_node(node);
1694 }
1695