xref: /linux/drivers/infiniband/hw/qib/qib_file_ops.c (revision 84b9b44b)
1 /*
2  * Copyright (c) 2012, 2013 Intel Corporation. All rights reserved.
3  * Copyright (c) 2006 - 2012 QLogic Corporation. All rights reserved.
4  * Copyright (c) 2003, 2004, 2005, 2006 PathScale, Inc. All rights reserved.
5  *
6  * This software is available to you under a choice of one of two
7  * licenses.  You may choose to be licensed under the terms of the GNU
8  * General Public License (GPL) Version 2, available from the file
9  * COPYING in the main directory of this source tree, or the
10  * OpenIB.org BSD license below:
11  *
12  *     Redistribution and use in source and binary forms, with or
13  *     without modification, are permitted provided that the following
14  *     conditions are met:
15  *
16  *      - Redistributions of source code must retain the above
17  *        copyright notice, this list of conditions and the following
18  *        disclaimer.
19  *
20  *      - Redistributions in binary form must reproduce the above
21  *        copyright notice, this list of conditions and the following
22  *        disclaimer in the documentation and/or other materials
23  *        provided with the distribution.
24  *
25  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
26  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
27  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
28  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
29  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
30  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
31  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
32  * SOFTWARE.
33  */
34 
35 #include <linux/pci.h>
36 #include <linux/poll.h>
37 #include <linux/cdev.h>
38 #include <linux/swap.h>
39 #include <linux/vmalloc.h>
40 #include <linux/highmem.h>
41 #include <linux/io.h>
42 #include <linux/jiffies.h>
43 #include <linux/delay.h>
44 #include <linux/export.h>
45 #include <linux/uio.h>
46 #include <linux/pgtable.h>
47 
48 #include <rdma/ib.h>
49 
50 #include "qib.h"
51 #include "qib_common.h"
52 #include "qib_user_sdma.h"
53 
54 #undef pr_fmt
55 #define pr_fmt(fmt) QIB_DRV_NAME ": " fmt
56 
57 static int qib_open(struct inode *, struct file *);
58 static int qib_close(struct inode *, struct file *);
59 static ssize_t qib_write(struct file *, const char __user *, size_t, loff_t *);
60 static ssize_t qib_write_iter(struct kiocb *, struct iov_iter *);
61 static __poll_t qib_poll(struct file *, struct poll_table_struct *);
62 static int qib_mmapf(struct file *, struct vm_area_struct *);
63 
64 /*
65  * This is really, really weird shit - write() and writev() here
66  * have completely unrelated semantics.  Sucky userland ABI,
67  * film at 11.
68  */
69 static const struct file_operations qib_file_ops = {
70 	.owner = THIS_MODULE,
71 	.write = qib_write,
72 	.write_iter = qib_write_iter,
73 	.open = qib_open,
74 	.release = qib_close,
75 	.poll = qib_poll,
76 	.mmap = qib_mmapf,
77 	.llseek = noop_llseek,
78 };
79 
80 /*
81  * Convert kernel virtual addresses to physical addresses so they don't
82  * potentially conflict with the chip addresses used as mmap offsets.
83  * It doesn't really matter what mmap offset we use as long as we can
84  * interpret it correctly.
85  */
86 static u64 cvt_kvaddr(void *p)
87 {
88 	struct page *page;
89 	u64 paddr = 0;
90 
91 	page = vmalloc_to_page(p);
92 	if (page)
93 		paddr = page_to_pfn(page) << PAGE_SHIFT;
94 
95 	return paddr;
96 }
97 
98 static int qib_get_base_info(struct file *fp, void __user *ubase,
99 			     size_t ubase_size)
100 {
101 	struct qib_ctxtdata *rcd = ctxt_fp(fp);
102 	int ret = 0;
103 	struct qib_base_info *kinfo = NULL;
104 	struct qib_devdata *dd = rcd->dd;
105 	struct qib_pportdata *ppd = rcd->ppd;
106 	unsigned subctxt_cnt;
107 	int shared, master;
108 	size_t sz;
109 
110 	subctxt_cnt = rcd->subctxt_cnt;
111 	if (!subctxt_cnt) {
112 		shared = 0;
113 		master = 0;
114 		subctxt_cnt = 1;
115 	} else {
116 		shared = 1;
117 		master = !subctxt_fp(fp);
118 	}
119 
120 	sz = sizeof(*kinfo);
121 	/* If context sharing is not requested, allow the old size structure */
122 	if (!shared)
123 		sz -= 7 * sizeof(u64);
124 	if (ubase_size < sz) {
125 		ret = -EINVAL;
126 		goto bail;
127 	}
128 
129 	kinfo = kzalloc(sizeof(*kinfo), GFP_KERNEL);
130 	if (kinfo == NULL) {
131 		ret = -ENOMEM;
132 		goto bail;
133 	}
134 
135 	ret = dd->f_get_base_info(rcd, kinfo);
136 	if (ret < 0)
137 		goto bail;
138 
139 	kinfo->spi_rcvhdr_cnt = dd->rcvhdrcnt;
140 	kinfo->spi_rcvhdrent_size = dd->rcvhdrentsize;
141 	kinfo->spi_tidegrcnt = rcd->rcvegrcnt;
142 	kinfo->spi_rcv_egrbufsize = dd->rcvegrbufsize;
143 	/*
144 	 * have to mmap whole thing
145 	 */
146 	kinfo->spi_rcv_egrbuftotlen =
147 		rcd->rcvegrbuf_chunks * rcd->rcvegrbuf_size;
148 	kinfo->spi_rcv_egrperchunk = rcd->rcvegrbufs_perchunk;
149 	kinfo->spi_rcv_egrchunksize = kinfo->spi_rcv_egrbuftotlen /
150 		rcd->rcvegrbuf_chunks;
151 	kinfo->spi_tidcnt = dd->rcvtidcnt / subctxt_cnt;
152 	if (master)
153 		kinfo->spi_tidcnt += dd->rcvtidcnt % subctxt_cnt;
154 	/*
155 	 * for this use, may be cfgctxts summed over all chips that
156 	 * are configured and present
157 	 */
158 	kinfo->spi_nctxts = dd->cfgctxts;
159 	/* unit (chip/board) our context is on */
160 	kinfo->spi_unit = dd->unit;
161 	kinfo->spi_port = ppd->port;
162 	/* for now, only a single page */
163 	kinfo->spi_tid_maxsize = PAGE_SIZE;
164 
165 	/*
166 	 * Doing this per context, and based on the skip value, etc.  This has
167 	 * to be the actual buffer size, since the protocol code treats it
168 	 * as an array.
169 	 *
170 	 * These have to be set to user addresses in the user code via mmap.
171 	 * These values are used on return to user code for the mmap target
172 	 * addresses only.  For 32 bit, same 44 bit address problem, so use
173 	 * the physical address, not virtual.  Before 2.6.11, using the
174 	 * page_address() macro worked, but in 2.6.11, even that returns the
175 	 * full 64 bit address (upper bits all 1's).  So far, using the
176 	 * physical addresses (or chip offsets, for chip mapping) works, but
177 	 * no doubt some future kernel release will change that, and we'll be
178 	 * on to yet another method of dealing with this.
179 	 * Normally only one of rcvhdr_tailaddr or rhf_offset is useful
180 	 * since the chips with non-zero rhf_offset don't normally
181 	 * enable tail register updates to host memory, but for testing,
182 	 * both can be enabled and used.
183 	 */
184 	kinfo->spi_rcvhdr_base = (u64) rcd->rcvhdrq_phys;
185 	kinfo->spi_rcvhdr_tailaddr = (u64) rcd->rcvhdrqtailaddr_phys;
186 	kinfo->spi_rhf_offset = dd->rhf_offset;
187 	kinfo->spi_rcv_egrbufs = (u64) rcd->rcvegr_phys;
188 	kinfo->spi_pioavailaddr = (u64) dd->pioavailregs_phys;
189 	/* setup per-unit (not port) status area for user programs */
190 	kinfo->spi_status = (u64) kinfo->spi_pioavailaddr +
191 		(char *) ppd->statusp -
192 		(char *) dd->pioavailregs_dma;
193 	kinfo->spi_uregbase = (u64) dd->uregbase + dd->ureg_align * rcd->ctxt;
194 	if (!shared) {
195 		kinfo->spi_piocnt = rcd->piocnt;
196 		kinfo->spi_piobufbase = (u64) rcd->piobufs;
197 		kinfo->spi_sendbuf_status = cvt_kvaddr(rcd->user_event_mask);
198 	} else if (master) {
199 		kinfo->spi_piocnt = (rcd->piocnt / subctxt_cnt) +
200 				    (rcd->piocnt % subctxt_cnt);
201 		/* Master's PIO buffers are after all the slave's */
202 		kinfo->spi_piobufbase = (u64) rcd->piobufs +
203 			dd->palign *
204 			(rcd->piocnt - kinfo->spi_piocnt);
205 	} else {
206 		unsigned slave = subctxt_fp(fp) - 1;
207 
208 		kinfo->spi_piocnt = rcd->piocnt / subctxt_cnt;
209 		kinfo->spi_piobufbase = (u64) rcd->piobufs +
210 			dd->palign * kinfo->spi_piocnt * slave;
211 	}
212 
213 	if (shared) {
214 		kinfo->spi_sendbuf_status =
215 			cvt_kvaddr(&rcd->user_event_mask[subctxt_fp(fp)]);
216 		/* only spi_subctxt_* fields should be set in this block! */
217 		kinfo->spi_subctxt_uregbase = cvt_kvaddr(rcd->subctxt_uregbase);
218 
219 		kinfo->spi_subctxt_rcvegrbuf =
220 			cvt_kvaddr(rcd->subctxt_rcvegrbuf);
221 		kinfo->spi_subctxt_rcvhdr_base =
222 			cvt_kvaddr(rcd->subctxt_rcvhdr_base);
223 	}
224 
225 	/*
226 	 * All user buffers are 2KB buffers.  If we ever support
227 	 * giving 4KB buffers to user processes, this will need some
228 	 * work.  Can't use piobufbase directly, because it has
229 	 * both 2K and 4K buffer base values.
230 	 */
231 	kinfo->spi_pioindex = (kinfo->spi_piobufbase - dd->pio2k_bufbase) /
232 		dd->palign;
233 	kinfo->spi_pioalign = dd->palign;
234 	kinfo->spi_qpair = QIB_KD_QP;
235 	/*
236 	 * user mode PIO buffers are always 2KB, even when 4KB can
237 	 * be received, and sent via the kernel; this is ibmaxlen
238 	 * for 2K MTU.
239 	 */
240 	kinfo->spi_piosize = dd->piosize2k - 2 * sizeof(u32);
241 	kinfo->spi_mtu = ppd->ibmaxlen; /* maxlen, not ibmtu */
242 	kinfo->spi_ctxt = rcd->ctxt;
243 	kinfo->spi_subctxt = subctxt_fp(fp);
244 	kinfo->spi_sw_version = QIB_KERN_SWVERSION;
245 	kinfo->spi_sw_version |= 1U << 31; /* QLogic-built, not kernel.org */
246 	kinfo->spi_hw_version = dd->revision;
247 
248 	if (master)
249 		kinfo->spi_runtime_flags |= QIB_RUNTIME_MASTER;
250 
251 	sz = (ubase_size < sizeof(*kinfo)) ? ubase_size : sizeof(*kinfo);
252 	if (copy_to_user(ubase, kinfo, sz))
253 		ret = -EFAULT;
254 bail:
255 	kfree(kinfo);
256 	return ret;
257 }
258 
259 /**
260  * qib_tid_update - update a context TID
261  * @rcd: the context
262  * @fp: the qib device file
263  * @ti: the TID information
264  *
265  * The new implementation as of Oct 2004 is that the driver assigns
266  * the tid and returns it to the caller.   To reduce search time, we
267  * keep a cursor for each context, walking the shadow tid array to find
268  * one that's not in use.
269  *
270  * For now, if we can't allocate the full list, we fail, although
271  * in the long run, we'll allocate as many as we can, and the
272  * caller will deal with that by trying the remaining pages later.
273  * That means that when we fail, we have to mark the tids as not in
274  * use again, in our shadow copy.
275  *
276  * It's up to the caller to free the tids when they are done.
277  * We'll unlock the pages as they free them.
278  *
279  * Also, right now we are locking one page at a time, but since
280  * the intended use of this routine is for a single group of
281  * virtually contiguous pages, that should change to improve
282  * performance.
283  */
284 static int qib_tid_update(struct qib_ctxtdata *rcd, struct file *fp,
285 			  const struct qib_tid_info *ti)
286 {
287 	int ret = 0, ntids;
288 	u32 tid, ctxttid, cnt, i, tidcnt, tidoff;
289 	u16 *tidlist;
290 	struct qib_devdata *dd = rcd->dd;
291 	u64 physaddr;
292 	unsigned long vaddr;
293 	u64 __iomem *tidbase;
294 	unsigned long tidmap[8];
295 	struct page **pagep = NULL;
296 	unsigned subctxt = subctxt_fp(fp);
297 
298 	if (!dd->pageshadow) {
299 		ret = -ENOMEM;
300 		goto done;
301 	}
302 
303 	cnt = ti->tidcnt;
304 	if (!cnt) {
305 		ret = -EFAULT;
306 		goto done;
307 	}
308 	ctxttid = rcd->ctxt * dd->rcvtidcnt;
309 	if (!rcd->subctxt_cnt) {
310 		tidcnt = dd->rcvtidcnt;
311 		tid = rcd->tidcursor;
312 		tidoff = 0;
313 	} else if (!subctxt) {
314 		tidcnt = (dd->rcvtidcnt / rcd->subctxt_cnt) +
315 			 (dd->rcvtidcnt % rcd->subctxt_cnt);
316 		tidoff = dd->rcvtidcnt - tidcnt;
317 		ctxttid += tidoff;
318 		tid = tidcursor_fp(fp);
319 	} else {
320 		tidcnt = dd->rcvtidcnt / rcd->subctxt_cnt;
321 		tidoff = tidcnt * (subctxt - 1);
322 		ctxttid += tidoff;
323 		tid = tidcursor_fp(fp);
324 	}
325 	if (cnt > tidcnt) {
326 		/* make sure it all fits in tid_pg_list */
327 		qib_devinfo(dd->pcidev,
328 			"Process tried to allocate %u TIDs, only trying max (%u)\n",
329 			cnt, tidcnt);
330 		cnt = tidcnt;
331 	}
332 	pagep = (struct page **) rcd->tid_pg_list;
333 	tidlist = (u16 *) &pagep[dd->rcvtidcnt];
334 	pagep += tidoff;
335 	tidlist += tidoff;
336 
337 	memset(tidmap, 0, sizeof(tidmap));
338 	/* before decrement; chip actual # */
339 	ntids = tidcnt;
340 	tidbase = (u64 __iomem *) (((char __iomem *) dd->kregbase) +
341 				   dd->rcvtidbase +
342 				   ctxttid * sizeof(*tidbase));
343 
344 	/* virtual address of first page in transfer */
345 	vaddr = ti->tidvaddr;
346 	if (!access_ok((void __user *) vaddr,
347 		       cnt * PAGE_SIZE)) {
348 		ret = -EFAULT;
349 		goto done;
350 	}
351 	ret = qib_get_user_pages(vaddr, cnt, pagep);
352 	if (ret) {
353 		/*
354 		 * if (ret == -EBUSY)
355 		 * We can't continue because the pagep array won't be
356 		 * initialized. This should never happen,
357 		 * unless perhaps the user has mpin'ed the pages
358 		 * themselves.
359 		 */
360 		qib_devinfo(
361 			dd->pcidev,
362 			"Failed to lock addr %p, %u pages: errno %d\n",
363 			(void *) vaddr, cnt, -ret);
364 		goto done;
365 	}
366 	for (i = 0; i < cnt; i++, vaddr += PAGE_SIZE) {
367 		dma_addr_t daddr;
368 
369 		for (; ntids--; tid++) {
370 			if (tid == tidcnt)
371 				tid = 0;
372 			if (!dd->pageshadow[ctxttid + tid])
373 				break;
374 		}
375 		if (ntids < 0) {
376 			/*
377 			 * Oops, wrapped all the way through their TIDs,
378 			 * and didn't have enough free; see comments at
379 			 * start of routine
380 			 */
381 			i--;    /* last tidlist[i] not filled in */
382 			ret = -ENOMEM;
383 			break;
384 		}
385 		ret = qib_map_page(dd->pcidev, pagep[i], &daddr);
386 		if (ret)
387 			break;
388 
389 		tidlist[i] = tid + tidoff;
390 		/* we "know" system pages and TID pages are same size */
391 		dd->pageshadow[ctxttid + tid] = pagep[i];
392 		dd->physshadow[ctxttid + tid] = daddr;
393 		/*
394 		 * don't need atomic or it's overhead
395 		 */
396 		__set_bit(tid, tidmap);
397 		physaddr = dd->physshadow[ctxttid + tid];
398 		/* PERFORMANCE: below should almost certainly be cached */
399 		dd->f_put_tid(dd, &tidbase[tid],
400 				  RCVHQ_RCV_TYPE_EXPECTED, physaddr);
401 		/*
402 		 * don't check this tid in qib_ctxtshadow, since we
403 		 * just filled it in; start with the next one.
404 		 */
405 		tid++;
406 	}
407 
408 	if (ret) {
409 		u32 limit;
410 cleanup:
411 		/* jump here if copy out of updated info failed... */
412 		/* same code that's in qib_free_tid() */
413 		limit = sizeof(tidmap) * BITS_PER_BYTE;
414 		if (limit > tidcnt)
415 			/* just in case size changes in future */
416 			limit = tidcnt;
417 		tid = find_first_bit((const unsigned long *)tidmap, limit);
418 		for (; tid < limit; tid++) {
419 			if (!test_bit(tid, tidmap))
420 				continue;
421 			if (dd->pageshadow[ctxttid + tid]) {
422 				dma_addr_t phys;
423 
424 				phys = dd->physshadow[ctxttid + tid];
425 				dd->physshadow[ctxttid + tid] = dd->tidinvalid;
426 				/* PERFORMANCE: below should almost certainly
427 				 * be cached
428 				 */
429 				dd->f_put_tid(dd, &tidbase[tid],
430 					      RCVHQ_RCV_TYPE_EXPECTED,
431 					      dd->tidinvalid);
432 				dma_unmap_page(&dd->pcidev->dev, phys,
433 					       PAGE_SIZE, DMA_FROM_DEVICE);
434 				dd->pageshadow[ctxttid + tid] = NULL;
435 			}
436 		}
437 		qib_release_user_pages(pagep, cnt);
438 	} else {
439 		/*
440 		 * Copy the updated array, with qib_tid's filled in, back
441 		 * to user.  Since we did the copy in already, this "should
442 		 * never fail" If it does, we have to clean up...
443 		 */
444 		if (copy_to_user((void __user *)
445 				 (unsigned long) ti->tidlist,
446 				 tidlist, cnt * sizeof(*tidlist))) {
447 			ret = -EFAULT;
448 			goto cleanup;
449 		}
450 		if (copy_to_user(u64_to_user_ptr(ti->tidmap),
451 				 tidmap, sizeof(tidmap))) {
452 			ret = -EFAULT;
453 			goto cleanup;
454 		}
455 		if (tid == tidcnt)
456 			tid = 0;
457 		if (!rcd->subctxt_cnt)
458 			rcd->tidcursor = tid;
459 		else
460 			tidcursor_fp(fp) = tid;
461 	}
462 
463 done:
464 	return ret;
465 }
466 
467 /**
468  * qib_tid_free - free a context TID
469  * @rcd: the context
470  * @subctxt: the subcontext
471  * @ti: the TID info
472  *
473  * right now we are unlocking one page at a time, but since
474  * the intended use of this routine is for a single group of
475  * virtually contiguous pages, that should change to improve
476  * performance.  We check that the TID is in range for this context
477  * but otherwise don't check validity; if user has an error and
478  * frees the wrong tid, it's only their own data that can thereby
479  * be corrupted.  We do check that the TID was in use, for sanity
480  * We always use our idea of the saved address, not the address that
481  * they pass in to us.
482  */
483 static int qib_tid_free(struct qib_ctxtdata *rcd, unsigned subctxt,
484 			const struct qib_tid_info *ti)
485 {
486 	int ret = 0;
487 	u32 tid, ctxttid, limit, tidcnt;
488 	struct qib_devdata *dd = rcd->dd;
489 	u64 __iomem *tidbase;
490 	unsigned long tidmap[8];
491 
492 	if (!dd->pageshadow) {
493 		ret = -ENOMEM;
494 		goto done;
495 	}
496 
497 	if (copy_from_user(tidmap, u64_to_user_ptr(ti->tidmap),
498 			   sizeof(tidmap))) {
499 		ret = -EFAULT;
500 		goto done;
501 	}
502 
503 	ctxttid = rcd->ctxt * dd->rcvtidcnt;
504 	if (!rcd->subctxt_cnt)
505 		tidcnt = dd->rcvtidcnt;
506 	else if (!subctxt) {
507 		tidcnt = (dd->rcvtidcnt / rcd->subctxt_cnt) +
508 			 (dd->rcvtidcnt % rcd->subctxt_cnt);
509 		ctxttid += dd->rcvtidcnt - tidcnt;
510 	} else {
511 		tidcnt = dd->rcvtidcnt / rcd->subctxt_cnt;
512 		ctxttid += tidcnt * (subctxt - 1);
513 	}
514 	tidbase = (u64 __iomem *) ((char __iomem *)(dd->kregbase) +
515 				   dd->rcvtidbase +
516 				   ctxttid * sizeof(*tidbase));
517 
518 	limit = sizeof(tidmap) * BITS_PER_BYTE;
519 	if (limit > tidcnt)
520 		/* just in case size changes in future */
521 		limit = tidcnt;
522 	tid = find_first_bit(tidmap, limit);
523 	for (; tid < limit; tid++) {
524 		/*
525 		 * small optimization; if we detect a run of 3 or so without
526 		 * any set, use find_first_bit again.  That's mainly to
527 		 * accelerate the case where we wrapped, so we have some at
528 		 * the beginning, and some at the end, and a big gap
529 		 * in the middle.
530 		 */
531 		if (!test_bit(tid, tidmap))
532 			continue;
533 
534 		if (dd->pageshadow[ctxttid + tid]) {
535 			struct page *p;
536 			dma_addr_t phys;
537 
538 			p = dd->pageshadow[ctxttid + tid];
539 			dd->pageshadow[ctxttid + tid] = NULL;
540 			phys = dd->physshadow[ctxttid + tid];
541 			dd->physshadow[ctxttid + tid] = dd->tidinvalid;
542 			/* PERFORMANCE: below should almost certainly be
543 			 * cached
544 			 */
545 			dd->f_put_tid(dd, &tidbase[tid],
546 				      RCVHQ_RCV_TYPE_EXPECTED, dd->tidinvalid);
547 			dma_unmap_page(&dd->pcidev->dev, phys, PAGE_SIZE,
548 				       DMA_FROM_DEVICE);
549 			qib_release_user_pages(&p, 1);
550 		}
551 	}
552 done:
553 	return ret;
554 }
555 
556 /**
557  * qib_set_part_key - set a partition key
558  * @rcd: the context
559  * @key: the key
560  *
561  * We can have up to 4 active at a time (other than the default, which is
562  * always allowed).  This is somewhat tricky, since multiple contexts may set
563  * the same key, so we reference count them, and clean up at exit.  All 4
564  * partition keys are packed into a single qlogic_ib register.  It's an
565  * error for a process to set the same pkey multiple times.  We provide no
566  * mechanism to de-allocate a pkey at this time, we may eventually need to
567  * do that.  I've used the atomic operations, and no locking, and only make
568  * a single pass through what's available.  This should be more than
569  * adequate for some time. I'll think about spinlocks or the like if and as
570  * it's necessary.
571  */
572 static int qib_set_part_key(struct qib_ctxtdata *rcd, u16 key)
573 {
574 	struct qib_pportdata *ppd = rcd->ppd;
575 	int i, pidx = -1;
576 	bool any = false;
577 	u16 lkey = key & 0x7FFF;
578 
579 	if (lkey == (QIB_DEFAULT_P_KEY & 0x7FFF))
580 		/* nothing to do; this key always valid */
581 		return 0;
582 
583 	if (!lkey)
584 		return -EINVAL;
585 
586 	/*
587 	 * Set the full membership bit, because it has to be
588 	 * set in the register or the packet, and it seems
589 	 * cleaner to set in the register than to force all
590 	 * callers to set it.
591 	 */
592 	key |= 0x8000;
593 
594 	for (i = 0; i < ARRAY_SIZE(rcd->pkeys); i++) {
595 		if (!rcd->pkeys[i] && pidx == -1)
596 			pidx = i;
597 		if (rcd->pkeys[i] == key)
598 			return -EEXIST;
599 	}
600 	if (pidx == -1)
601 		return -EBUSY;
602 	for (i = 0; i < ARRAY_SIZE(ppd->pkeys); i++) {
603 		if (!ppd->pkeys[i]) {
604 			any = true;
605 			continue;
606 		}
607 		if (ppd->pkeys[i] == key) {
608 			atomic_t *pkrefs = &ppd->pkeyrefs[i];
609 
610 			if (atomic_inc_return(pkrefs) > 1) {
611 				rcd->pkeys[pidx] = key;
612 				return 0;
613 			}
614 			/*
615 			 * lost race, decrement count, catch below
616 			 */
617 			atomic_dec(pkrefs);
618 			any = true;
619 		}
620 		if ((ppd->pkeys[i] & 0x7FFF) == lkey)
621 			/*
622 			 * It makes no sense to have both the limited and
623 			 * full membership PKEY set at the same time since
624 			 * the unlimited one will disable the limited one.
625 			 */
626 			return -EEXIST;
627 	}
628 	if (!any)
629 		return -EBUSY;
630 	for (i = 0; i < ARRAY_SIZE(ppd->pkeys); i++) {
631 		if (!ppd->pkeys[i] &&
632 		    atomic_inc_return(&ppd->pkeyrefs[i]) == 1) {
633 			rcd->pkeys[pidx] = key;
634 			ppd->pkeys[i] = key;
635 			(void) ppd->dd->f_set_ib_cfg(ppd, QIB_IB_CFG_PKEYS, 0);
636 			return 0;
637 		}
638 	}
639 	return -EBUSY;
640 }
641 
642 /**
643  * qib_manage_rcvq - manage a context's receive queue
644  * @rcd: the context
645  * @subctxt: the subcontext
646  * @start_stop: action to carry out
647  *
648  * start_stop == 0 disables receive on the context, for use in queue
649  * overflow conditions.  start_stop==1 re-enables, to be used to
650  * re-init the software copy of the head register
651  */
652 static int qib_manage_rcvq(struct qib_ctxtdata *rcd, unsigned subctxt,
653 			   int start_stop)
654 {
655 	struct qib_devdata *dd = rcd->dd;
656 	unsigned int rcvctrl_op;
657 
658 	if (subctxt)
659 		goto bail;
660 	/* atomically clear receive enable ctxt. */
661 	if (start_stop) {
662 		/*
663 		 * On enable, force in-memory copy of the tail register to
664 		 * 0, so that protocol code doesn't have to worry about
665 		 * whether or not the chip has yet updated the in-memory
666 		 * copy or not on return from the system call. The chip
667 		 * always resets it's tail register back to 0 on a
668 		 * transition from disabled to enabled.
669 		 */
670 		if (rcd->rcvhdrtail_kvaddr)
671 			qib_clear_rcvhdrtail(rcd);
672 		rcvctrl_op = QIB_RCVCTRL_CTXT_ENB;
673 	} else
674 		rcvctrl_op = QIB_RCVCTRL_CTXT_DIS;
675 	dd->f_rcvctrl(rcd->ppd, rcvctrl_op, rcd->ctxt);
676 	/* always; new head should be equal to new tail; see above */
677 bail:
678 	return 0;
679 }
680 
681 static void qib_clean_part_key(struct qib_ctxtdata *rcd,
682 			       struct qib_devdata *dd)
683 {
684 	int i, j, pchanged = 0;
685 	struct qib_pportdata *ppd = rcd->ppd;
686 
687 	for (i = 0; i < ARRAY_SIZE(rcd->pkeys); i++) {
688 		if (!rcd->pkeys[i])
689 			continue;
690 		for (j = 0; j < ARRAY_SIZE(ppd->pkeys); j++) {
691 			/* check for match independent of the global bit */
692 			if ((ppd->pkeys[j] & 0x7fff) !=
693 			    (rcd->pkeys[i] & 0x7fff))
694 				continue;
695 			if (atomic_dec_and_test(&ppd->pkeyrefs[j])) {
696 				ppd->pkeys[j] = 0;
697 				pchanged++;
698 			}
699 			break;
700 		}
701 		rcd->pkeys[i] = 0;
702 	}
703 	if (pchanged)
704 		(void) ppd->dd->f_set_ib_cfg(ppd, QIB_IB_CFG_PKEYS, 0);
705 }
706 
707 /* common code for the mappings on dma_alloc_coherent mem */
708 static int qib_mmap_mem(struct vm_area_struct *vma, struct qib_ctxtdata *rcd,
709 			unsigned len, void *kvaddr, u32 write_ok, char *what)
710 {
711 	struct qib_devdata *dd = rcd->dd;
712 	unsigned long pfn;
713 	int ret;
714 
715 	if ((vma->vm_end - vma->vm_start) > len) {
716 		qib_devinfo(dd->pcidev,
717 			 "FAIL on %s: len %lx > %x\n", what,
718 			 vma->vm_end - vma->vm_start, len);
719 		ret = -EFAULT;
720 		goto bail;
721 	}
722 
723 	/*
724 	 * shared context user code requires rcvhdrq mapped r/w, others
725 	 * only allowed readonly mapping.
726 	 */
727 	if (!write_ok) {
728 		if (vma->vm_flags & VM_WRITE) {
729 			qib_devinfo(dd->pcidev,
730 				 "%s must be mapped readonly\n", what);
731 			ret = -EPERM;
732 			goto bail;
733 		}
734 
735 		/* don't allow them to later change with mprotect */
736 		vm_flags_clear(vma, VM_MAYWRITE);
737 	}
738 
739 	pfn = virt_to_phys(kvaddr) >> PAGE_SHIFT;
740 	ret = remap_pfn_range(vma, vma->vm_start, pfn,
741 			      len, vma->vm_page_prot);
742 	if (ret)
743 		qib_devinfo(dd->pcidev,
744 			"%s ctxt%u mmap of %lx, %x bytes failed: %d\n",
745 			what, rcd->ctxt, pfn, len, ret);
746 bail:
747 	return ret;
748 }
749 
750 static int mmap_ureg(struct vm_area_struct *vma, struct qib_devdata *dd,
751 		     u64 ureg)
752 {
753 	unsigned long phys;
754 	unsigned long sz;
755 	int ret;
756 
757 	/*
758 	 * This is real hardware, so use io_remap.  This is the mechanism
759 	 * for the user process to update the head registers for their ctxt
760 	 * in the chip.
761 	 */
762 	sz = dd->flags & QIB_HAS_HDRSUPP ? 2 * PAGE_SIZE : PAGE_SIZE;
763 	if ((vma->vm_end - vma->vm_start) > sz) {
764 		qib_devinfo(dd->pcidev,
765 			"FAIL mmap userreg: reqlen %lx > PAGE\n",
766 			vma->vm_end - vma->vm_start);
767 		ret = -EFAULT;
768 	} else {
769 		phys = dd->physaddr + ureg;
770 		vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
771 
772 		vm_flags_set(vma, VM_DONTCOPY | VM_DONTEXPAND);
773 		ret = io_remap_pfn_range(vma, vma->vm_start,
774 					 phys >> PAGE_SHIFT,
775 					 vma->vm_end - vma->vm_start,
776 					 vma->vm_page_prot);
777 	}
778 	return ret;
779 }
780 
781 static int mmap_piobufs(struct vm_area_struct *vma,
782 			struct qib_devdata *dd,
783 			struct qib_ctxtdata *rcd,
784 			unsigned piobufs, unsigned piocnt)
785 {
786 	unsigned long phys;
787 	int ret;
788 
789 	/*
790 	 * When we map the PIO buffers in the chip, we want to map them as
791 	 * writeonly, no read possible; unfortunately, x86 doesn't allow
792 	 * for this in hardware, but we still prevent users from asking
793 	 * for it.
794 	 */
795 	if ((vma->vm_end - vma->vm_start) > (piocnt * dd->palign)) {
796 		qib_devinfo(dd->pcidev,
797 			"FAIL mmap piobufs: reqlen %lx > PAGE\n",
798 			 vma->vm_end - vma->vm_start);
799 		ret = -EINVAL;
800 		goto bail;
801 	}
802 
803 	phys = dd->physaddr + piobufs;
804 
805 #if defined(__powerpc__)
806 	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
807 #endif
808 
809 	/*
810 	 * don't allow them to later change to readable with mprotect (for when
811 	 * not initially mapped readable, as is normally the case)
812 	 */
813 	vm_flags_mod(vma, VM_DONTCOPY | VM_DONTEXPAND, VM_MAYREAD);
814 
815 	/* We used PAT if wc_cookie == 0 */
816 	if (!dd->wc_cookie)
817 		vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot);
818 
819 	ret = io_remap_pfn_range(vma, vma->vm_start, phys >> PAGE_SHIFT,
820 				 vma->vm_end - vma->vm_start,
821 				 vma->vm_page_prot);
822 bail:
823 	return ret;
824 }
825 
826 static int mmap_rcvegrbufs(struct vm_area_struct *vma,
827 			   struct qib_ctxtdata *rcd)
828 {
829 	struct qib_devdata *dd = rcd->dd;
830 	unsigned long start, size;
831 	size_t total_size, i;
832 	unsigned long pfn;
833 	int ret;
834 
835 	size = rcd->rcvegrbuf_size;
836 	total_size = rcd->rcvegrbuf_chunks * size;
837 	if ((vma->vm_end - vma->vm_start) > total_size) {
838 		qib_devinfo(dd->pcidev,
839 			"FAIL on egr bufs: reqlen %lx > actual %lx\n",
840 			 vma->vm_end - vma->vm_start,
841 			 (unsigned long) total_size);
842 		ret = -EINVAL;
843 		goto bail;
844 	}
845 
846 	if (vma->vm_flags & VM_WRITE) {
847 		qib_devinfo(dd->pcidev,
848 			"Can't map eager buffers as writable (flags=%lx)\n",
849 			vma->vm_flags);
850 		ret = -EPERM;
851 		goto bail;
852 	}
853 	/* don't allow them to later change to writable with mprotect */
854 	vm_flags_clear(vma, VM_MAYWRITE);
855 
856 	start = vma->vm_start;
857 
858 	for (i = 0; i < rcd->rcvegrbuf_chunks; i++, start += size) {
859 		pfn = virt_to_phys(rcd->rcvegrbuf[i]) >> PAGE_SHIFT;
860 		ret = remap_pfn_range(vma, start, pfn, size,
861 				      vma->vm_page_prot);
862 		if (ret < 0)
863 			goto bail;
864 	}
865 	ret = 0;
866 
867 bail:
868 	return ret;
869 }
870 
871 /*
872  * qib_file_vma_fault - handle a VMA page fault.
873  */
874 static vm_fault_t qib_file_vma_fault(struct vm_fault *vmf)
875 {
876 	struct page *page;
877 
878 	page = vmalloc_to_page((void *)(vmf->pgoff << PAGE_SHIFT));
879 	if (!page)
880 		return VM_FAULT_SIGBUS;
881 
882 	get_page(page);
883 	vmf->page = page;
884 
885 	return 0;
886 }
887 
888 static const struct vm_operations_struct qib_file_vm_ops = {
889 	.fault = qib_file_vma_fault,
890 };
891 
892 static int mmap_kvaddr(struct vm_area_struct *vma, u64 pgaddr,
893 		       struct qib_ctxtdata *rcd, unsigned subctxt)
894 {
895 	struct qib_devdata *dd = rcd->dd;
896 	unsigned subctxt_cnt;
897 	unsigned long len;
898 	void *addr;
899 	size_t size;
900 	int ret = 0;
901 
902 	subctxt_cnt = rcd->subctxt_cnt;
903 	size = rcd->rcvegrbuf_chunks * rcd->rcvegrbuf_size;
904 
905 	/*
906 	 * Each process has all the subctxt uregbase, rcvhdrq, and
907 	 * rcvegrbufs mmapped - as an array for all the processes,
908 	 * and also separately for this process.
909 	 */
910 	if (pgaddr == cvt_kvaddr(rcd->subctxt_uregbase)) {
911 		addr = rcd->subctxt_uregbase;
912 		size = PAGE_SIZE * subctxt_cnt;
913 	} else if (pgaddr == cvt_kvaddr(rcd->subctxt_rcvhdr_base)) {
914 		addr = rcd->subctxt_rcvhdr_base;
915 		size = rcd->rcvhdrq_size * subctxt_cnt;
916 	} else if (pgaddr == cvt_kvaddr(rcd->subctxt_rcvegrbuf)) {
917 		addr = rcd->subctxt_rcvegrbuf;
918 		size *= subctxt_cnt;
919 	} else if (pgaddr == cvt_kvaddr(rcd->subctxt_uregbase +
920 					PAGE_SIZE * subctxt)) {
921 		addr = rcd->subctxt_uregbase + PAGE_SIZE * subctxt;
922 		size = PAGE_SIZE;
923 	} else if (pgaddr == cvt_kvaddr(rcd->subctxt_rcvhdr_base +
924 					rcd->rcvhdrq_size * subctxt)) {
925 		addr = rcd->subctxt_rcvhdr_base +
926 			rcd->rcvhdrq_size * subctxt;
927 		size = rcd->rcvhdrq_size;
928 	} else if (pgaddr == cvt_kvaddr(&rcd->user_event_mask[subctxt])) {
929 		addr = rcd->user_event_mask;
930 		size = PAGE_SIZE;
931 	} else if (pgaddr == cvt_kvaddr(rcd->subctxt_rcvegrbuf +
932 					size * subctxt)) {
933 		addr = rcd->subctxt_rcvegrbuf + size * subctxt;
934 		/* rcvegrbufs are read-only on the slave */
935 		if (vma->vm_flags & VM_WRITE) {
936 			qib_devinfo(dd->pcidev,
937 				 "Can't map eager buffers as writable (flags=%lx)\n",
938 				 vma->vm_flags);
939 			ret = -EPERM;
940 			goto bail;
941 		}
942 		/*
943 		 * Don't allow permission to later change to writable
944 		 * with mprotect.
945 		 */
946 		vm_flags_clear(vma, VM_MAYWRITE);
947 	} else
948 		goto bail;
949 	len = vma->vm_end - vma->vm_start;
950 	if (len > size) {
951 		ret = -EINVAL;
952 		goto bail;
953 	}
954 
955 	vma->vm_pgoff = (unsigned long) addr >> PAGE_SHIFT;
956 	vma->vm_ops = &qib_file_vm_ops;
957 	vm_flags_set(vma, VM_DONTEXPAND | VM_DONTDUMP);
958 	ret = 1;
959 
960 bail:
961 	return ret;
962 }
963 
964 /**
965  * qib_mmapf - mmap various structures into user space
966  * @fp: the file pointer
967  * @vma: the VM area
968  *
969  * We use this to have a shared buffer between the kernel and the user code
970  * for the rcvhdr queue, egr buffers, and the per-context user regs and pio
971  * buffers in the chip.  We have the open and close entries so we can bump
972  * the ref count and keep the driver from being unloaded while still mapped.
973  */
974 static int qib_mmapf(struct file *fp, struct vm_area_struct *vma)
975 {
976 	struct qib_ctxtdata *rcd;
977 	struct qib_devdata *dd;
978 	u64 pgaddr, ureg;
979 	unsigned piobufs, piocnt;
980 	int ret, match = 1;
981 
982 	rcd = ctxt_fp(fp);
983 	if (!rcd || !(vma->vm_flags & VM_SHARED)) {
984 		ret = -EINVAL;
985 		goto bail;
986 	}
987 	dd = rcd->dd;
988 
989 	/*
990 	 * This is the qib_do_user_init() code, mapping the shared buffers
991 	 * and per-context user registers into the user process. The address
992 	 * referred to by vm_pgoff is the file offset passed via mmap().
993 	 * For shared contexts, this is the kernel vmalloc() address of the
994 	 * pages to share with the master.
995 	 * For non-shared or master ctxts, this is a physical address.
996 	 * We only do one mmap for each space mapped.
997 	 */
998 	pgaddr = vma->vm_pgoff << PAGE_SHIFT;
999 
1000 	/*
1001 	 * Check for 0 in case one of the allocations failed, but user
1002 	 * called mmap anyway.
1003 	 */
1004 	if (!pgaddr)  {
1005 		ret = -EINVAL;
1006 		goto bail;
1007 	}
1008 
1009 	/*
1010 	 * Physical addresses must fit in 40 bits for our hardware.
1011 	 * Check for kernel virtual addresses first, anything else must
1012 	 * match a HW or memory address.
1013 	 */
1014 	ret = mmap_kvaddr(vma, pgaddr, rcd, subctxt_fp(fp));
1015 	if (ret) {
1016 		if (ret > 0)
1017 			ret = 0;
1018 		goto bail;
1019 	}
1020 
1021 	ureg = dd->uregbase + dd->ureg_align * rcd->ctxt;
1022 	if (!rcd->subctxt_cnt) {
1023 		/* ctxt is not shared */
1024 		piocnt = rcd->piocnt;
1025 		piobufs = rcd->piobufs;
1026 	} else if (!subctxt_fp(fp)) {
1027 		/* caller is the master */
1028 		piocnt = (rcd->piocnt / rcd->subctxt_cnt) +
1029 			 (rcd->piocnt % rcd->subctxt_cnt);
1030 		piobufs = rcd->piobufs +
1031 			dd->palign * (rcd->piocnt - piocnt);
1032 	} else {
1033 		unsigned slave = subctxt_fp(fp) - 1;
1034 
1035 		/* caller is a slave */
1036 		piocnt = rcd->piocnt / rcd->subctxt_cnt;
1037 		piobufs = rcd->piobufs + dd->palign * piocnt * slave;
1038 	}
1039 
1040 	if (pgaddr == ureg)
1041 		ret = mmap_ureg(vma, dd, ureg);
1042 	else if (pgaddr == piobufs)
1043 		ret = mmap_piobufs(vma, dd, rcd, piobufs, piocnt);
1044 	else if (pgaddr == dd->pioavailregs_phys)
1045 		/* in-memory copy of pioavail registers */
1046 		ret = qib_mmap_mem(vma, rcd, PAGE_SIZE,
1047 				   (void *) dd->pioavailregs_dma, 0,
1048 				   "pioavail registers");
1049 	else if (pgaddr == rcd->rcvegr_phys)
1050 		ret = mmap_rcvegrbufs(vma, rcd);
1051 	else if (pgaddr == (u64) rcd->rcvhdrq_phys)
1052 		/*
1053 		 * The rcvhdrq itself; multiple pages, contiguous
1054 		 * from an i/o perspective.  Shared contexts need
1055 		 * to map r/w, so we allow writing.
1056 		 */
1057 		ret = qib_mmap_mem(vma, rcd, rcd->rcvhdrq_size,
1058 				   rcd->rcvhdrq, 1, "rcvhdrq");
1059 	else if (pgaddr == (u64) rcd->rcvhdrqtailaddr_phys)
1060 		/* in-memory copy of rcvhdrq tail register */
1061 		ret = qib_mmap_mem(vma, rcd, PAGE_SIZE,
1062 				   rcd->rcvhdrtail_kvaddr, 0,
1063 				   "rcvhdrq tail");
1064 	else
1065 		match = 0;
1066 	if (!match)
1067 		ret = -EINVAL;
1068 
1069 	vma->vm_private_data = NULL;
1070 
1071 	if (ret < 0)
1072 		qib_devinfo(dd->pcidev,
1073 			 "mmap Failure %d: off %llx len %lx\n",
1074 			 -ret, (unsigned long long)pgaddr,
1075 			 vma->vm_end - vma->vm_start);
1076 bail:
1077 	return ret;
1078 }
1079 
1080 static __poll_t qib_poll_urgent(struct qib_ctxtdata *rcd,
1081 				    struct file *fp,
1082 				    struct poll_table_struct *pt)
1083 {
1084 	struct qib_devdata *dd = rcd->dd;
1085 	__poll_t pollflag;
1086 
1087 	poll_wait(fp, &rcd->wait, pt);
1088 
1089 	spin_lock_irq(&dd->uctxt_lock);
1090 	if (rcd->urgent != rcd->urgent_poll) {
1091 		pollflag = EPOLLIN | EPOLLRDNORM;
1092 		rcd->urgent_poll = rcd->urgent;
1093 	} else {
1094 		pollflag = 0;
1095 		set_bit(QIB_CTXT_WAITING_URG, &rcd->flag);
1096 	}
1097 	spin_unlock_irq(&dd->uctxt_lock);
1098 
1099 	return pollflag;
1100 }
1101 
1102 static __poll_t qib_poll_next(struct qib_ctxtdata *rcd,
1103 				  struct file *fp,
1104 				  struct poll_table_struct *pt)
1105 {
1106 	struct qib_devdata *dd = rcd->dd;
1107 	__poll_t pollflag;
1108 
1109 	poll_wait(fp, &rcd->wait, pt);
1110 
1111 	spin_lock_irq(&dd->uctxt_lock);
1112 	if (dd->f_hdrqempty(rcd)) {
1113 		set_bit(QIB_CTXT_WAITING_RCV, &rcd->flag);
1114 		dd->f_rcvctrl(rcd->ppd, QIB_RCVCTRL_INTRAVAIL_ENB, rcd->ctxt);
1115 		pollflag = 0;
1116 	} else
1117 		pollflag = EPOLLIN | EPOLLRDNORM;
1118 	spin_unlock_irq(&dd->uctxt_lock);
1119 
1120 	return pollflag;
1121 }
1122 
1123 static __poll_t qib_poll(struct file *fp, struct poll_table_struct *pt)
1124 {
1125 	struct qib_ctxtdata *rcd;
1126 	__poll_t pollflag;
1127 
1128 	rcd = ctxt_fp(fp);
1129 	if (!rcd)
1130 		pollflag = EPOLLERR;
1131 	else if (rcd->poll_type == QIB_POLL_TYPE_URGENT)
1132 		pollflag = qib_poll_urgent(rcd, fp, pt);
1133 	else  if (rcd->poll_type == QIB_POLL_TYPE_ANYRCV)
1134 		pollflag = qib_poll_next(rcd, fp, pt);
1135 	else /* invalid */
1136 		pollflag = EPOLLERR;
1137 
1138 	return pollflag;
1139 }
1140 
1141 static void assign_ctxt_affinity(struct file *fp, struct qib_devdata *dd)
1142 {
1143 	struct qib_filedata *fd = fp->private_data;
1144 	const unsigned int weight = current->nr_cpus_allowed;
1145 	const struct cpumask *local_mask = cpumask_of_pcibus(dd->pcidev->bus);
1146 	int local_cpu;
1147 
1148 	/*
1149 	 * If process has NOT already set it's affinity, select and
1150 	 * reserve a processor for it on the local NUMA node.
1151 	 */
1152 	if ((weight >= qib_cpulist_count) &&
1153 		(cpumask_weight(local_mask) <= qib_cpulist_count)) {
1154 		for_each_cpu(local_cpu, local_mask)
1155 			if (!test_and_set_bit(local_cpu, qib_cpulist)) {
1156 				fd->rec_cpu_num = local_cpu;
1157 				return;
1158 			}
1159 	}
1160 
1161 	/*
1162 	 * If process has NOT already set it's affinity, select and
1163 	 * reserve a processor for it, as a rendevous for all
1164 	 * users of the driver.  If they don't actually later
1165 	 * set affinity to this cpu, or set it to some other cpu,
1166 	 * it just means that sooner or later we don't recommend
1167 	 * a cpu, and let the scheduler do it's best.
1168 	 */
1169 	if (weight >= qib_cpulist_count) {
1170 		int cpu;
1171 
1172 		cpu = find_first_zero_bit(qib_cpulist,
1173 					  qib_cpulist_count);
1174 		if (cpu == qib_cpulist_count)
1175 			qib_dev_err(dd,
1176 			"no cpus avail for affinity PID %u\n",
1177 			current->pid);
1178 		else {
1179 			__set_bit(cpu, qib_cpulist);
1180 			fd->rec_cpu_num = cpu;
1181 		}
1182 	}
1183 }
1184 
1185 /*
1186  * Check that userland and driver are compatible for subcontexts.
1187  */
1188 static int qib_compatible_subctxts(int user_swmajor, int user_swminor)
1189 {
1190 	/* this code is written long-hand for clarity */
1191 	if (QIB_USER_SWMAJOR != user_swmajor) {
1192 		/* no promise of compatibility if major mismatch */
1193 		return 0;
1194 	}
1195 	if (QIB_USER_SWMAJOR == 1) {
1196 		switch (QIB_USER_SWMINOR) {
1197 		case 0:
1198 		case 1:
1199 		case 2:
1200 			/* no subctxt implementation so cannot be compatible */
1201 			return 0;
1202 		case 3:
1203 			/* 3 is only compatible with itself */
1204 			return user_swminor == 3;
1205 		default:
1206 			/* >= 4 are compatible (or are expected to be) */
1207 			return user_swminor <= QIB_USER_SWMINOR;
1208 		}
1209 	}
1210 	/* make no promises yet for future major versions */
1211 	return 0;
1212 }
1213 
1214 static int init_subctxts(struct qib_devdata *dd,
1215 			 struct qib_ctxtdata *rcd,
1216 			 const struct qib_user_info *uinfo)
1217 {
1218 	int ret = 0;
1219 	unsigned num_subctxts;
1220 	size_t size;
1221 
1222 	/*
1223 	 * If the user is requesting zero subctxts,
1224 	 * skip the subctxt allocation.
1225 	 */
1226 	if (uinfo->spu_subctxt_cnt <= 0)
1227 		goto bail;
1228 	num_subctxts = uinfo->spu_subctxt_cnt;
1229 
1230 	/* Check for subctxt compatibility */
1231 	if (!qib_compatible_subctxts(uinfo->spu_userversion >> 16,
1232 		uinfo->spu_userversion & 0xffff)) {
1233 		qib_devinfo(dd->pcidev,
1234 			 "Mismatched user version (%d.%d) and driver version (%d.%d) while context sharing. Ensure that driver and library are from the same release.\n",
1235 			 (int) (uinfo->spu_userversion >> 16),
1236 			 (int) (uinfo->spu_userversion & 0xffff),
1237 			 QIB_USER_SWMAJOR, QIB_USER_SWMINOR);
1238 		goto bail;
1239 	}
1240 	if (num_subctxts > QLOGIC_IB_MAX_SUBCTXT) {
1241 		ret = -EINVAL;
1242 		goto bail;
1243 	}
1244 
1245 	rcd->subctxt_uregbase = vmalloc_user(PAGE_SIZE * num_subctxts);
1246 	if (!rcd->subctxt_uregbase) {
1247 		ret = -ENOMEM;
1248 		goto bail;
1249 	}
1250 	/* Note: rcd->rcvhdrq_size isn't initialized yet. */
1251 	size = ALIGN(dd->rcvhdrcnt * dd->rcvhdrentsize *
1252 		     sizeof(u32), PAGE_SIZE) * num_subctxts;
1253 	rcd->subctxt_rcvhdr_base = vmalloc_user(size);
1254 	if (!rcd->subctxt_rcvhdr_base) {
1255 		ret = -ENOMEM;
1256 		goto bail_ureg;
1257 	}
1258 
1259 	rcd->subctxt_rcvegrbuf = vmalloc_user(rcd->rcvegrbuf_chunks *
1260 					      rcd->rcvegrbuf_size *
1261 					      num_subctxts);
1262 	if (!rcd->subctxt_rcvegrbuf) {
1263 		ret = -ENOMEM;
1264 		goto bail_rhdr;
1265 	}
1266 
1267 	rcd->subctxt_cnt = uinfo->spu_subctxt_cnt;
1268 	rcd->subctxt_id = uinfo->spu_subctxt_id;
1269 	rcd->active_slaves = 1;
1270 	rcd->redirect_seq_cnt = 1;
1271 	set_bit(QIB_CTXT_MASTER_UNINIT, &rcd->flag);
1272 	goto bail;
1273 
1274 bail_rhdr:
1275 	vfree(rcd->subctxt_rcvhdr_base);
1276 bail_ureg:
1277 	vfree(rcd->subctxt_uregbase);
1278 	rcd->subctxt_uregbase = NULL;
1279 bail:
1280 	return ret;
1281 }
1282 
1283 static int setup_ctxt(struct qib_pportdata *ppd, int ctxt,
1284 		      struct file *fp, const struct qib_user_info *uinfo)
1285 {
1286 	struct qib_filedata *fd = fp->private_data;
1287 	struct qib_devdata *dd = ppd->dd;
1288 	struct qib_ctxtdata *rcd;
1289 	void *ptmp = NULL;
1290 	int ret;
1291 	int numa_id;
1292 
1293 	assign_ctxt_affinity(fp, dd);
1294 
1295 	numa_id = qib_numa_aware ? ((fd->rec_cpu_num != -1) ?
1296 		cpu_to_node(fd->rec_cpu_num) :
1297 		numa_node_id()) : dd->assigned_node_id;
1298 
1299 	rcd = qib_create_ctxtdata(ppd, ctxt, numa_id);
1300 
1301 	/*
1302 	 * Allocate memory for use in qib_tid_update() at open to
1303 	 * reduce cost of expected send setup per message segment
1304 	 */
1305 	if (rcd)
1306 		ptmp = kmalloc(dd->rcvtidcnt * sizeof(u16) +
1307 			       dd->rcvtidcnt * sizeof(struct page **),
1308 			       GFP_KERNEL);
1309 
1310 	if (!rcd || !ptmp) {
1311 		qib_dev_err(dd,
1312 			"Unable to allocate ctxtdata memory, failing open\n");
1313 		ret = -ENOMEM;
1314 		goto bailerr;
1315 	}
1316 	rcd->userversion = uinfo->spu_userversion;
1317 	ret = init_subctxts(dd, rcd, uinfo);
1318 	if (ret)
1319 		goto bailerr;
1320 	rcd->tid_pg_list = ptmp;
1321 	rcd->pid = current->pid;
1322 	init_waitqueue_head(&dd->rcd[ctxt]->wait);
1323 	get_task_comm(rcd->comm, current);
1324 	ctxt_fp(fp) = rcd;
1325 	qib_stats.sps_ctxts++;
1326 	dd->freectxts--;
1327 	ret = 0;
1328 	goto bail;
1329 
1330 bailerr:
1331 	if (fd->rec_cpu_num != -1)
1332 		__clear_bit(fd->rec_cpu_num, qib_cpulist);
1333 
1334 	dd->rcd[ctxt] = NULL;
1335 	kfree(rcd);
1336 	kfree(ptmp);
1337 bail:
1338 	return ret;
1339 }
1340 
1341 static inline int usable(struct qib_pportdata *ppd)
1342 {
1343 	struct qib_devdata *dd = ppd->dd;
1344 
1345 	return dd && (dd->flags & QIB_PRESENT) && dd->kregbase && ppd->lid &&
1346 		(ppd->lflags & QIBL_LINKACTIVE);
1347 }
1348 
1349 /*
1350  * Select a context on the given device, either using a requested port
1351  * or the port based on the context number.
1352  */
1353 static int choose_port_ctxt(struct file *fp, struct qib_devdata *dd, u32 port,
1354 			    const struct qib_user_info *uinfo)
1355 {
1356 	struct qib_pportdata *ppd = NULL;
1357 	int ret, ctxt;
1358 
1359 	if (port) {
1360 		if (!usable(dd->pport + port - 1)) {
1361 			ret = -ENETDOWN;
1362 			goto done;
1363 		} else
1364 			ppd = dd->pport + port - 1;
1365 	}
1366 	for (ctxt = dd->first_user_ctxt; ctxt < dd->cfgctxts && dd->rcd[ctxt];
1367 	     ctxt++)
1368 		;
1369 	if (ctxt == dd->cfgctxts) {
1370 		ret = -EBUSY;
1371 		goto done;
1372 	}
1373 	if (!ppd) {
1374 		u32 pidx = ctxt % dd->num_pports;
1375 
1376 		if (usable(dd->pport + pidx))
1377 			ppd = dd->pport + pidx;
1378 		else {
1379 			for (pidx = 0; pidx < dd->num_pports && !ppd;
1380 			     pidx++)
1381 				if (usable(dd->pport + pidx))
1382 					ppd = dd->pport + pidx;
1383 		}
1384 	}
1385 	ret = ppd ? setup_ctxt(ppd, ctxt, fp, uinfo) : -ENETDOWN;
1386 done:
1387 	return ret;
1388 }
1389 
1390 static int find_free_ctxt(int unit, struct file *fp,
1391 			  const struct qib_user_info *uinfo)
1392 {
1393 	struct qib_devdata *dd = qib_lookup(unit);
1394 	int ret;
1395 
1396 	if (!dd || (uinfo->spu_port && uinfo->spu_port > dd->num_pports))
1397 		ret = -ENODEV;
1398 	else
1399 		ret = choose_port_ctxt(fp, dd, uinfo->spu_port, uinfo);
1400 
1401 	return ret;
1402 }
1403 
1404 static int get_a_ctxt(struct file *fp, const struct qib_user_info *uinfo,
1405 		      unsigned alg)
1406 {
1407 	struct qib_devdata *udd = NULL;
1408 	int ret = 0, devmax, npresent, nup, ndev, dusable = 0, i;
1409 	u32 port = uinfo->spu_port, ctxt;
1410 
1411 	devmax = qib_count_units(&npresent, &nup);
1412 	if (!npresent) {
1413 		ret = -ENXIO;
1414 		goto done;
1415 	}
1416 	if (nup == 0) {
1417 		ret = -ENETDOWN;
1418 		goto done;
1419 	}
1420 
1421 	if (alg == QIB_PORT_ALG_ACROSS) {
1422 		unsigned inuse = ~0U;
1423 
1424 		/* find device (with ACTIVE ports) with fewest ctxts in use */
1425 		for (ndev = 0; ndev < devmax; ndev++) {
1426 			struct qib_devdata *dd = qib_lookup(ndev);
1427 			unsigned cused = 0, cfree = 0, pusable = 0;
1428 
1429 			if (!dd)
1430 				continue;
1431 			if (port && port <= dd->num_pports &&
1432 			    usable(dd->pport + port - 1))
1433 				pusable = 1;
1434 			else
1435 				for (i = 0; i < dd->num_pports; i++)
1436 					if (usable(dd->pport + i))
1437 						pusable++;
1438 			if (!pusable)
1439 				continue;
1440 			for (ctxt = dd->first_user_ctxt; ctxt < dd->cfgctxts;
1441 			     ctxt++)
1442 				if (dd->rcd[ctxt])
1443 					cused++;
1444 				else
1445 					cfree++;
1446 			if (cfree && cused < inuse) {
1447 				udd = dd;
1448 				inuse = cused;
1449 			}
1450 		}
1451 		if (udd) {
1452 			ret = choose_port_ctxt(fp, udd, port, uinfo);
1453 			goto done;
1454 		}
1455 	} else {
1456 		for (ndev = 0; ndev < devmax; ndev++) {
1457 			struct qib_devdata *dd = qib_lookup(ndev);
1458 
1459 			if (dd) {
1460 				ret = choose_port_ctxt(fp, dd, port, uinfo);
1461 				if (!ret)
1462 					goto done;
1463 				if (ret == -EBUSY)
1464 					dusable++;
1465 			}
1466 		}
1467 	}
1468 	ret = dusable ? -EBUSY : -ENETDOWN;
1469 
1470 done:
1471 	return ret;
1472 }
1473 
1474 static int find_shared_ctxt(struct file *fp,
1475 			    const struct qib_user_info *uinfo)
1476 {
1477 	int devmax, ndev, i;
1478 	int ret = 0;
1479 
1480 	devmax = qib_count_units(NULL, NULL);
1481 
1482 	for (ndev = 0; ndev < devmax; ndev++) {
1483 		struct qib_devdata *dd = qib_lookup(ndev);
1484 
1485 		/* device portion of usable() */
1486 		if (!(dd && (dd->flags & QIB_PRESENT) && dd->kregbase))
1487 			continue;
1488 		for (i = dd->first_user_ctxt; i < dd->cfgctxts; i++) {
1489 			struct qib_ctxtdata *rcd = dd->rcd[i];
1490 
1491 			/* Skip ctxts which are not yet open */
1492 			if (!rcd || !rcd->cnt)
1493 				continue;
1494 			/* Skip ctxt if it doesn't match the requested one */
1495 			if (rcd->subctxt_id != uinfo->spu_subctxt_id)
1496 				continue;
1497 			/* Verify the sharing process matches the master */
1498 			if (rcd->subctxt_cnt != uinfo->spu_subctxt_cnt ||
1499 			    rcd->userversion != uinfo->spu_userversion ||
1500 			    rcd->cnt >= rcd->subctxt_cnt) {
1501 				ret = -EINVAL;
1502 				goto done;
1503 			}
1504 			ctxt_fp(fp) = rcd;
1505 			subctxt_fp(fp) = rcd->cnt++;
1506 			rcd->subpid[subctxt_fp(fp)] = current->pid;
1507 			tidcursor_fp(fp) = 0;
1508 			rcd->active_slaves |= 1 << subctxt_fp(fp);
1509 			ret = 1;
1510 			goto done;
1511 		}
1512 	}
1513 
1514 done:
1515 	return ret;
1516 }
1517 
1518 static int qib_open(struct inode *in, struct file *fp)
1519 {
1520 	/* The real work is performed later in qib_assign_ctxt() */
1521 	fp->private_data = kzalloc(sizeof(struct qib_filedata), GFP_KERNEL);
1522 	if (fp->private_data) /* no cpu affinity by default */
1523 		((struct qib_filedata *)fp->private_data)->rec_cpu_num = -1;
1524 	return fp->private_data ? 0 : -ENOMEM;
1525 }
1526 
1527 static int find_hca(unsigned int cpu, int *unit)
1528 {
1529 	int ret = 0, devmax, npresent, nup, ndev;
1530 
1531 	*unit = -1;
1532 
1533 	devmax = qib_count_units(&npresent, &nup);
1534 	if (!npresent) {
1535 		ret = -ENXIO;
1536 		goto done;
1537 	}
1538 	if (!nup) {
1539 		ret = -ENETDOWN;
1540 		goto done;
1541 	}
1542 	for (ndev = 0; ndev < devmax; ndev++) {
1543 		struct qib_devdata *dd = qib_lookup(ndev);
1544 
1545 		if (dd) {
1546 			if (pcibus_to_node(dd->pcidev->bus) < 0) {
1547 				ret = -EINVAL;
1548 				goto done;
1549 			}
1550 			if (cpu_to_node(cpu) ==
1551 				pcibus_to_node(dd->pcidev->bus)) {
1552 				*unit = ndev;
1553 				goto done;
1554 			}
1555 		}
1556 	}
1557 done:
1558 	return ret;
1559 }
1560 
1561 static int do_qib_user_sdma_queue_create(struct file *fp)
1562 {
1563 	struct qib_filedata *fd = fp->private_data;
1564 	struct qib_ctxtdata *rcd = fd->rcd;
1565 	struct qib_devdata *dd = rcd->dd;
1566 
1567 	if (dd->flags & QIB_HAS_SEND_DMA) {
1568 
1569 		fd->pq = qib_user_sdma_queue_create(&dd->pcidev->dev,
1570 						    dd->unit,
1571 						    rcd->ctxt,
1572 						    fd->subctxt);
1573 		if (!fd->pq)
1574 			return -ENOMEM;
1575 	}
1576 
1577 	return 0;
1578 }
1579 
1580 /*
1581  * Get ctxt early, so can set affinity prior to memory allocation.
1582  */
1583 static int qib_assign_ctxt(struct file *fp, const struct qib_user_info *uinfo)
1584 {
1585 	int ret;
1586 	int i_minor;
1587 	unsigned swmajor, swminor, alg = QIB_PORT_ALG_ACROSS;
1588 
1589 	/* Check to be sure we haven't already initialized this file */
1590 	if (ctxt_fp(fp)) {
1591 		ret = -EINVAL;
1592 		goto done;
1593 	}
1594 
1595 	/* for now, if major version is different, bail */
1596 	swmajor = uinfo->spu_userversion >> 16;
1597 	if (swmajor != QIB_USER_SWMAJOR) {
1598 		ret = -ENODEV;
1599 		goto done;
1600 	}
1601 
1602 	swminor = uinfo->spu_userversion & 0xffff;
1603 
1604 	if (swminor >= 11 && uinfo->spu_port_alg < QIB_PORT_ALG_COUNT)
1605 		alg = uinfo->spu_port_alg;
1606 
1607 	mutex_lock(&qib_mutex);
1608 
1609 	if (qib_compatible_subctxts(swmajor, swminor) &&
1610 	    uinfo->spu_subctxt_cnt) {
1611 		ret = find_shared_ctxt(fp, uinfo);
1612 		if (ret > 0) {
1613 			ret = do_qib_user_sdma_queue_create(fp);
1614 			if (!ret)
1615 				assign_ctxt_affinity(fp, (ctxt_fp(fp))->dd);
1616 			goto done_ok;
1617 		}
1618 	}
1619 
1620 	i_minor = iminor(file_inode(fp)) - QIB_USER_MINOR_BASE;
1621 	if (i_minor)
1622 		ret = find_free_ctxt(i_minor - 1, fp, uinfo);
1623 	else {
1624 		int unit;
1625 		const unsigned int cpu = cpumask_first(current->cpus_ptr);
1626 		const unsigned int weight = current->nr_cpus_allowed;
1627 
1628 		if (weight == 1 && !test_bit(cpu, qib_cpulist))
1629 			if (!find_hca(cpu, &unit) && unit >= 0)
1630 				if (!find_free_ctxt(unit, fp, uinfo)) {
1631 					ret = 0;
1632 					goto done_chk_sdma;
1633 				}
1634 		ret = get_a_ctxt(fp, uinfo, alg);
1635 	}
1636 
1637 done_chk_sdma:
1638 	if (!ret)
1639 		ret = do_qib_user_sdma_queue_create(fp);
1640 done_ok:
1641 	mutex_unlock(&qib_mutex);
1642 
1643 done:
1644 	return ret;
1645 }
1646 
1647 
1648 static int qib_do_user_init(struct file *fp,
1649 			    const struct qib_user_info *uinfo)
1650 {
1651 	int ret;
1652 	struct qib_ctxtdata *rcd = ctxt_fp(fp);
1653 	struct qib_devdata *dd;
1654 	unsigned uctxt;
1655 
1656 	/* Subctxts don't need to initialize anything since master did it. */
1657 	if (subctxt_fp(fp)) {
1658 		ret = wait_event_interruptible(rcd->wait,
1659 			!test_bit(QIB_CTXT_MASTER_UNINIT, &rcd->flag));
1660 		goto bail;
1661 	}
1662 
1663 	dd = rcd->dd;
1664 
1665 	/* some ctxts may get extra buffers, calculate that here */
1666 	uctxt = rcd->ctxt - dd->first_user_ctxt;
1667 	if (uctxt < dd->ctxts_extrabuf) {
1668 		rcd->piocnt = dd->pbufsctxt + 1;
1669 		rcd->pio_base = rcd->piocnt * uctxt;
1670 	} else {
1671 		rcd->piocnt = dd->pbufsctxt;
1672 		rcd->pio_base = rcd->piocnt * uctxt +
1673 			dd->ctxts_extrabuf;
1674 	}
1675 
1676 	/*
1677 	 * All user buffers are 2KB buffers.  If we ever support
1678 	 * giving 4KB buffers to user processes, this will need some
1679 	 * work.  Can't use piobufbase directly, because it has
1680 	 * both 2K and 4K buffer base values.  So check and handle.
1681 	 */
1682 	if ((rcd->pio_base + rcd->piocnt) > dd->piobcnt2k) {
1683 		if (rcd->pio_base >= dd->piobcnt2k) {
1684 			qib_dev_err(dd,
1685 				    "%u:ctxt%u: no 2KB buffers available\n",
1686 				    dd->unit, rcd->ctxt);
1687 			ret = -ENOBUFS;
1688 			goto bail;
1689 		}
1690 		rcd->piocnt = dd->piobcnt2k - rcd->pio_base;
1691 		qib_dev_err(dd, "Ctxt%u: would use 4KB bufs, using %u\n",
1692 			    rcd->ctxt, rcd->piocnt);
1693 	}
1694 
1695 	rcd->piobufs = dd->pio2k_bufbase + rcd->pio_base * dd->palign;
1696 	qib_chg_pioavailkernel(dd, rcd->pio_base, rcd->piocnt,
1697 			       TXCHK_CHG_TYPE_USER, rcd);
1698 	/*
1699 	 * try to ensure that processes start up with consistent avail update
1700 	 * for their own range, at least.   If system very quiet, it might
1701 	 * have the in-memory copy out of date at startup for this range of
1702 	 * buffers, when a context gets re-used.  Do after the chg_pioavail
1703 	 * and before the rest of setup, so it's "almost certain" the dma
1704 	 * will have occurred (can't 100% guarantee, but should be many
1705 	 * decimals of 9s, with this ordering), given how much else happens
1706 	 * after this.
1707 	 */
1708 	dd->f_sendctrl(dd->pport, QIB_SENDCTRL_AVAIL_BLIP);
1709 
1710 	/*
1711 	 * Now allocate the rcvhdr Q and eager TIDs; skip the TID
1712 	 * array for time being.  If rcd->ctxt > chip-supported,
1713 	 * we need to do extra stuff here to handle by handling overflow
1714 	 * through ctxt 0, someday
1715 	 */
1716 	ret = qib_create_rcvhdrq(dd, rcd);
1717 	if (!ret)
1718 		ret = qib_setup_eagerbufs(rcd);
1719 	if (ret)
1720 		goto bail_pio;
1721 
1722 	rcd->tidcursor = 0; /* start at beginning after open */
1723 
1724 	/* initialize poll variables... */
1725 	rcd->urgent = 0;
1726 	rcd->urgent_poll = 0;
1727 
1728 	/*
1729 	 * Now enable the ctxt for receive.
1730 	 * For chips that are set to DMA the tail register to memory
1731 	 * when they change (and when the update bit transitions from
1732 	 * 0 to 1.  So for those chips, we turn it off and then back on.
1733 	 * This will (very briefly) affect any other open ctxts, but the
1734 	 * duration is very short, and therefore isn't an issue.  We
1735 	 * explicitly set the in-memory tail copy to 0 beforehand, so we
1736 	 * don't have to wait to be sure the DMA update has happened
1737 	 * (chip resets head/tail to 0 on transition to enable).
1738 	 */
1739 	if (rcd->rcvhdrtail_kvaddr)
1740 		qib_clear_rcvhdrtail(rcd);
1741 
1742 	dd->f_rcvctrl(rcd->ppd, QIB_RCVCTRL_CTXT_ENB | QIB_RCVCTRL_TIDFLOW_ENB,
1743 		      rcd->ctxt);
1744 
1745 	/* Notify any waiting slaves */
1746 	if (rcd->subctxt_cnt) {
1747 		clear_bit(QIB_CTXT_MASTER_UNINIT, &rcd->flag);
1748 		wake_up(&rcd->wait);
1749 	}
1750 	return 0;
1751 
1752 bail_pio:
1753 	qib_chg_pioavailkernel(dd, rcd->pio_base, rcd->piocnt,
1754 			       TXCHK_CHG_TYPE_KERN, rcd);
1755 bail:
1756 	return ret;
1757 }
1758 
1759 /**
1760  * unlock_expected_tids - unlock any expected TID entries context still had
1761  * in use
1762  * @rcd: ctxt
1763  *
1764  * We don't actually update the chip here, because we do a bulk update
1765  * below, using f_clear_tids.
1766  */
1767 static void unlock_expected_tids(struct qib_ctxtdata *rcd)
1768 {
1769 	struct qib_devdata *dd = rcd->dd;
1770 	int ctxt_tidbase = rcd->ctxt * dd->rcvtidcnt;
1771 	int i, maxtid = ctxt_tidbase + dd->rcvtidcnt;
1772 
1773 	for (i = ctxt_tidbase; i < maxtid; i++) {
1774 		struct page *p = dd->pageshadow[i];
1775 		dma_addr_t phys;
1776 
1777 		if (!p)
1778 			continue;
1779 
1780 		phys = dd->physshadow[i];
1781 		dd->physshadow[i] = dd->tidinvalid;
1782 		dd->pageshadow[i] = NULL;
1783 		dma_unmap_page(&dd->pcidev->dev, phys, PAGE_SIZE,
1784 			       DMA_FROM_DEVICE);
1785 		qib_release_user_pages(&p, 1);
1786 	}
1787 }
1788 
1789 static int qib_close(struct inode *in, struct file *fp)
1790 {
1791 	struct qib_filedata *fd;
1792 	struct qib_ctxtdata *rcd;
1793 	struct qib_devdata *dd;
1794 	unsigned long flags;
1795 	unsigned ctxt;
1796 
1797 	mutex_lock(&qib_mutex);
1798 
1799 	fd = fp->private_data;
1800 	fp->private_data = NULL;
1801 	rcd = fd->rcd;
1802 	if (!rcd) {
1803 		mutex_unlock(&qib_mutex);
1804 		goto bail;
1805 	}
1806 
1807 	dd = rcd->dd;
1808 
1809 	/* ensure all pio buffer writes in progress are flushed */
1810 	qib_flush_wc();
1811 
1812 	/* drain user sdma queue */
1813 	if (fd->pq) {
1814 		qib_user_sdma_queue_drain(rcd->ppd, fd->pq);
1815 		qib_user_sdma_queue_destroy(fd->pq);
1816 	}
1817 
1818 	if (fd->rec_cpu_num != -1)
1819 		__clear_bit(fd->rec_cpu_num, qib_cpulist);
1820 
1821 	if (--rcd->cnt) {
1822 		/*
1823 		 * XXX If the master closes the context before the slave(s),
1824 		 * revoke the mmap for the eager receive queue so
1825 		 * the slave(s) don't wait for receive data forever.
1826 		 */
1827 		rcd->active_slaves &= ~(1 << fd->subctxt);
1828 		rcd->subpid[fd->subctxt] = 0;
1829 		mutex_unlock(&qib_mutex);
1830 		goto bail;
1831 	}
1832 
1833 	/* early; no interrupt users after this */
1834 	spin_lock_irqsave(&dd->uctxt_lock, flags);
1835 	ctxt = rcd->ctxt;
1836 	dd->rcd[ctxt] = NULL;
1837 	rcd->pid = 0;
1838 	spin_unlock_irqrestore(&dd->uctxt_lock, flags);
1839 
1840 	if (rcd->rcvwait_to || rcd->piowait_to ||
1841 	    rcd->rcvnowait || rcd->pionowait) {
1842 		rcd->rcvwait_to = 0;
1843 		rcd->piowait_to = 0;
1844 		rcd->rcvnowait = 0;
1845 		rcd->pionowait = 0;
1846 	}
1847 	if (rcd->flag)
1848 		rcd->flag = 0;
1849 
1850 	if (dd->kregbase) {
1851 		/* atomically clear receive enable ctxt and intr avail. */
1852 		dd->f_rcvctrl(rcd->ppd, QIB_RCVCTRL_CTXT_DIS |
1853 				  QIB_RCVCTRL_INTRAVAIL_DIS, ctxt);
1854 
1855 		/* clean up the pkeys for this ctxt user */
1856 		qib_clean_part_key(rcd, dd);
1857 		qib_disarm_piobufs(dd, rcd->pio_base, rcd->piocnt);
1858 		qib_chg_pioavailkernel(dd, rcd->pio_base,
1859 				       rcd->piocnt, TXCHK_CHG_TYPE_KERN, NULL);
1860 
1861 		dd->f_clear_tids(dd, rcd);
1862 
1863 		if (dd->pageshadow)
1864 			unlock_expected_tids(rcd);
1865 		qib_stats.sps_ctxts--;
1866 		dd->freectxts++;
1867 	}
1868 
1869 	mutex_unlock(&qib_mutex);
1870 	qib_free_ctxtdata(dd, rcd); /* after releasing the mutex */
1871 
1872 bail:
1873 	kfree(fd);
1874 	return 0;
1875 }
1876 
1877 static int qib_ctxt_info(struct file *fp, struct qib_ctxt_info __user *uinfo)
1878 {
1879 	struct qib_ctxt_info info;
1880 	int ret;
1881 	size_t sz;
1882 	struct qib_ctxtdata *rcd = ctxt_fp(fp);
1883 	struct qib_filedata *fd;
1884 
1885 	fd = fp->private_data;
1886 
1887 	info.num_active = qib_count_active_units();
1888 	info.unit = rcd->dd->unit;
1889 	info.port = rcd->ppd->port;
1890 	info.ctxt = rcd->ctxt;
1891 	info.subctxt =  subctxt_fp(fp);
1892 	/* Number of user ctxts available for this device. */
1893 	info.num_ctxts = rcd->dd->cfgctxts - rcd->dd->first_user_ctxt;
1894 	info.num_subctxts = rcd->subctxt_cnt;
1895 	info.rec_cpu = fd->rec_cpu_num;
1896 	sz = sizeof(info);
1897 
1898 	if (copy_to_user(uinfo, &info, sz)) {
1899 		ret = -EFAULT;
1900 		goto bail;
1901 	}
1902 	ret = 0;
1903 
1904 bail:
1905 	return ret;
1906 }
1907 
1908 static int qib_sdma_get_inflight(struct qib_user_sdma_queue *pq,
1909 				 u32 __user *inflightp)
1910 {
1911 	const u32 val = qib_user_sdma_inflight_counter(pq);
1912 
1913 	if (put_user(val, inflightp))
1914 		return -EFAULT;
1915 
1916 	return 0;
1917 }
1918 
1919 static int qib_sdma_get_complete(struct qib_pportdata *ppd,
1920 				 struct qib_user_sdma_queue *pq,
1921 				 u32 __user *completep)
1922 {
1923 	u32 val;
1924 	int err;
1925 
1926 	if (!pq)
1927 		return -EINVAL;
1928 
1929 	err = qib_user_sdma_make_progress(ppd, pq);
1930 	if (err < 0)
1931 		return err;
1932 
1933 	val = qib_user_sdma_complete_counter(pq);
1934 	if (put_user(val, completep))
1935 		return -EFAULT;
1936 
1937 	return 0;
1938 }
1939 
1940 static int disarm_req_delay(struct qib_ctxtdata *rcd)
1941 {
1942 	int ret = 0;
1943 
1944 	if (!usable(rcd->ppd)) {
1945 		int i;
1946 		/*
1947 		 * if link is down, or otherwise not usable, delay
1948 		 * the caller up to 30 seconds, so we don't thrash
1949 		 * in trying to get the chip back to ACTIVE, and
1950 		 * set flag so they make the call again.
1951 		 */
1952 		if (rcd->user_event_mask) {
1953 			/*
1954 			 * subctxt_cnt is 0 if not shared, so do base
1955 			 * separately, first, then remaining subctxt, if any
1956 			 */
1957 			set_bit(_QIB_EVENT_DISARM_BUFS_BIT,
1958 				&rcd->user_event_mask[0]);
1959 			for (i = 1; i < rcd->subctxt_cnt; i++)
1960 				set_bit(_QIB_EVENT_DISARM_BUFS_BIT,
1961 					&rcd->user_event_mask[i]);
1962 		}
1963 		for (i = 0; !usable(rcd->ppd) && i < 300; i++)
1964 			msleep(100);
1965 		ret = -ENETDOWN;
1966 	}
1967 	return ret;
1968 }
1969 
1970 /*
1971  * Find all user contexts in use, and set the specified bit in their
1972  * event mask.
1973  * See also find_ctxt() for a similar use, that is specific to send buffers.
1974  */
1975 int qib_set_uevent_bits(struct qib_pportdata *ppd, const int evtbit)
1976 {
1977 	struct qib_ctxtdata *rcd;
1978 	unsigned ctxt;
1979 	int ret = 0;
1980 	unsigned long flags;
1981 
1982 	spin_lock_irqsave(&ppd->dd->uctxt_lock, flags);
1983 	for (ctxt = ppd->dd->first_user_ctxt; ctxt < ppd->dd->cfgctxts;
1984 	     ctxt++) {
1985 		rcd = ppd->dd->rcd[ctxt];
1986 		if (!rcd)
1987 			continue;
1988 		if (rcd->user_event_mask) {
1989 			int i;
1990 			/*
1991 			 * subctxt_cnt is 0 if not shared, so do base
1992 			 * separately, first, then remaining subctxt, if any
1993 			 */
1994 			set_bit(evtbit, &rcd->user_event_mask[0]);
1995 			for (i = 1; i < rcd->subctxt_cnt; i++)
1996 				set_bit(evtbit, &rcd->user_event_mask[i]);
1997 		}
1998 		ret = 1;
1999 		break;
2000 	}
2001 	spin_unlock_irqrestore(&ppd->dd->uctxt_lock, flags);
2002 
2003 	return ret;
2004 }
2005 
2006 /*
2007  * clear the event notifier events for this context.
2008  * For the DISARM_BUFS case, we also take action (this obsoletes
2009  * the older QIB_CMD_DISARM_BUFS, but we keep it for backwards
2010  * compatibility.
2011  * Other bits don't currently require actions, just atomically clear.
2012  * User process then performs actions appropriate to bit having been
2013  * set, if desired, and checks again in future.
2014  */
2015 static int qib_user_event_ack(struct qib_ctxtdata *rcd, int subctxt,
2016 			      unsigned long events)
2017 {
2018 	int ret = 0, i;
2019 
2020 	for (i = 0; i <= _QIB_MAX_EVENT_BIT; i++) {
2021 		if (!test_bit(i, &events))
2022 			continue;
2023 		if (i == _QIB_EVENT_DISARM_BUFS_BIT) {
2024 			(void)qib_disarm_piobufs_ifneeded(rcd);
2025 			ret = disarm_req_delay(rcd);
2026 		} else
2027 			clear_bit(i, &rcd->user_event_mask[subctxt]);
2028 	}
2029 	return ret;
2030 }
2031 
2032 static ssize_t qib_write(struct file *fp, const char __user *data,
2033 			 size_t count, loff_t *off)
2034 {
2035 	const struct qib_cmd __user *ucmd;
2036 	struct qib_ctxtdata *rcd;
2037 	const void __user *src;
2038 	size_t consumed, copy = 0;
2039 	struct qib_cmd cmd;
2040 	ssize_t ret = 0;
2041 	void *dest;
2042 
2043 	if (!ib_safe_file_access(fp)) {
2044 		pr_err_once("qib_write: process %d (%s) changed security contexts after opening file descriptor, this is not allowed.\n",
2045 			    task_tgid_vnr(current), current->comm);
2046 		return -EACCES;
2047 	}
2048 
2049 	if (count < sizeof(cmd.type)) {
2050 		ret = -EINVAL;
2051 		goto bail;
2052 	}
2053 
2054 	ucmd = (const struct qib_cmd __user *) data;
2055 
2056 	if (copy_from_user(&cmd.type, &ucmd->type, sizeof(cmd.type))) {
2057 		ret = -EFAULT;
2058 		goto bail;
2059 	}
2060 
2061 	consumed = sizeof(cmd.type);
2062 
2063 	switch (cmd.type) {
2064 	case QIB_CMD_ASSIGN_CTXT:
2065 	case QIB_CMD_USER_INIT:
2066 		copy = sizeof(cmd.cmd.user_info);
2067 		dest = &cmd.cmd.user_info;
2068 		src = &ucmd->cmd.user_info;
2069 		break;
2070 
2071 	case QIB_CMD_RECV_CTRL:
2072 		copy = sizeof(cmd.cmd.recv_ctrl);
2073 		dest = &cmd.cmd.recv_ctrl;
2074 		src = &ucmd->cmd.recv_ctrl;
2075 		break;
2076 
2077 	case QIB_CMD_CTXT_INFO:
2078 		copy = sizeof(cmd.cmd.ctxt_info);
2079 		dest = &cmd.cmd.ctxt_info;
2080 		src = &ucmd->cmd.ctxt_info;
2081 		break;
2082 
2083 	case QIB_CMD_TID_UPDATE:
2084 	case QIB_CMD_TID_FREE:
2085 		copy = sizeof(cmd.cmd.tid_info);
2086 		dest = &cmd.cmd.tid_info;
2087 		src = &ucmd->cmd.tid_info;
2088 		break;
2089 
2090 	case QIB_CMD_SET_PART_KEY:
2091 		copy = sizeof(cmd.cmd.part_key);
2092 		dest = &cmd.cmd.part_key;
2093 		src = &ucmd->cmd.part_key;
2094 		break;
2095 
2096 	case QIB_CMD_DISARM_BUFS:
2097 	case QIB_CMD_PIOAVAILUPD: /* force an update of PIOAvail reg */
2098 		copy = 0;
2099 		src = NULL;
2100 		dest = NULL;
2101 		break;
2102 
2103 	case QIB_CMD_POLL_TYPE:
2104 		copy = sizeof(cmd.cmd.poll_type);
2105 		dest = &cmd.cmd.poll_type;
2106 		src = &ucmd->cmd.poll_type;
2107 		break;
2108 
2109 	case QIB_CMD_ARMLAUNCH_CTRL:
2110 		copy = sizeof(cmd.cmd.armlaunch_ctrl);
2111 		dest = &cmd.cmd.armlaunch_ctrl;
2112 		src = &ucmd->cmd.armlaunch_ctrl;
2113 		break;
2114 
2115 	case QIB_CMD_SDMA_INFLIGHT:
2116 		copy = sizeof(cmd.cmd.sdma_inflight);
2117 		dest = &cmd.cmd.sdma_inflight;
2118 		src = &ucmd->cmd.sdma_inflight;
2119 		break;
2120 
2121 	case QIB_CMD_SDMA_COMPLETE:
2122 		copy = sizeof(cmd.cmd.sdma_complete);
2123 		dest = &cmd.cmd.sdma_complete;
2124 		src = &ucmd->cmd.sdma_complete;
2125 		break;
2126 
2127 	case QIB_CMD_ACK_EVENT:
2128 		copy = sizeof(cmd.cmd.event_mask);
2129 		dest = &cmd.cmd.event_mask;
2130 		src = &ucmd->cmd.event_mask;
2131 		break;
2132 
2133 	default:
2134 		ret = -EINVAL;
2135 		goto bail;
2136 	}
2137 
2138 	if (copy) {
2139 		if ((count - consumed) < copy) {
2140 			ret = -EINVAL;
2141 			goto bail;
2142 		}
2143 		if (copy_from_user(dest, src, copy)) {
2144 			ret = -EFAULT;
2145 			goto bail;
2146 		}
2147 		consumed += copy;
2148 	}
2149 
2150 	rcd = ctxt_fp(fp);
2151 	if (!rcd && cmd.type != QIB_CMD_ASSIGN_CTXT) {
2152 		ret = -EINVAL;
2153 		goto bail;
2154 	}
2155 
2156 	switch (cmd.type) {
2157 	case QIB_CMD_ASSIGN_CTXT:
2158 		if (rcd) {
2159 			ret = -EINVAL;
2160 			goto bail;
2161 		}
2162 
2163 		ret = qib_assign_ctxt(fp, &cmd.cmd.user_info);
2164 		if (ret)
2165 			goto bail;
2166 		break;
2167 
2168 	case QIB_CMD_USER_INIT:
2169 		ret = qib_do_user_init(fp, &cmd.cmd.user_info);
2170 		if (ret)
2171 			goto bail;
2172 		ret = qib_get_base_info(fp, u64_to_user_ptr(
2173 					  cmd.cmd.user_info.spu_base_info),
2174 					cmd.cmd.user_info.spu_base_info_size);
2175 		break;
2176 
2177 	case QIB_CMD_RECV_CTRL:
2178 		ret = qib_manage_rcvq(rcd, subctxt_fp(fp), cmd.cmd.recv_ctrl);
2179 		break;
2180 
2181 	case QIB_CMD_CTXT_INFO:
2182 		ret = qib_ctxt_info(fp, (struct qib_ctxt_info __user *)
2183 				    (unsigned long) cmd.cmd.ctxt_info);
2184 		break;
2185 
2186 	case QIB_CMD_TID_UPDATE:
2187 		ret = qib_tid_update(rcd, fp, &cmd.cmd.tid_info);
2188 		break;
2189 
2190 	case QIB_CMD_TID_FREE:
2191 		ret = qib_tid_free(rcd, subctxt_fp(fp), &cmd.cmd.tid_info);
2192 		break;
2193 
2194 	case QIB_CMD_SET_PART_KEY:
2195 		ret = qib_set_part_key(rcd, cmd.cmd.part_key);
2196 		break;
2197 
2198 	case QIB_CMD_DISARM_BUFS:
2199 		(void)qib_disarm_piobufs_ifneeded(rcd);
2200 		ret = disarm_req_delay(rcd);
2201 		break;
2202 
2203 	case QIB_CMD_PIOAVAILUPD:
2204 		qib_force_pio_avail_update(rcd->dd);
2205 		break;
2206 
2207 	case QIB_CMD_POLL_TYPE:
2208 		rcd->poll_type = cmd.cmd.poll_type;
2209 		break;
2210 
2211 	case QIB_CMD_ARMLAUNCH_CTRL:
2212 		rcd->dd->f_set_armlaunch(rcd->dd, cmd.cmd.armlaunch_ctrl);
2213 		break;
2214 
2215 	case QIB_CMD_SDMA_INFLIGHT:
2216 		ret = qib_sdma_get_inflight(user_sdma_queue_fp(fp),
2217 					    (u32 __user *) (unsigned long)
2218 					    cmd.cmd.sdma_inflight);
2219 		break;
2220 
2221 	case QIB_CMD_SDMA_COMPLETE:
2222 		ret = qib_sdma_get_complete(rcd->ppd,
2223 					    user_sdma_queue_fp(fp),
2224 					    (u32 __user *) (unsigned long)
2225 					    cmd.cmd.sdma_complete);
2226 		break;
2227 
2228 	case QIB_CMD_ACK_EVENT:
2229 		ret = qib_user_event_ack(rcd, subctxt_fp(fp),
2230 					 cmd.cmd.event_mask);
2231 		break;
2232 	}
2233 
2234 	if (ret >= 0)
2235 		ret = consumed;
2236 
2237 bail:
2238 	return ret;
2239 }
2240 
2241 static ssize_t qib_write_iter(struct kiocb *iocb, struct iov_iter *from)
2242 {
2243 	struct qib_filedata *fp = iocb->ki_filp->private_data;
2244 	struct qib_ctxtdata *rcd = ctxt_fp(iocb->ki_filp);
2245 	struct qib_user_sdma_queue *pq = fp->pq;
2246 
2247 	if (!from->user_backed || !from->nr_segs || !pq)
2248 		return -EINVAL;
2249 
2250 	return qib_user_sdma_writev(rcd, pq, iter_iov(from), from->nr_segs);
2251 }
2252 
2253 static struct class *qib_class;
2254 static dev_t qib_dev;
2255 
2256 int qib_cdev_init(int minor, const char *name,
2257 		  const struct file_operations *fops,
2258 		  struct cdev **cdevp, struct device **devp)
2259 {
2260 	const dev_t dev = MKDEV(MAJOR(qib_dev), minor);
2261 	struct cdev *cdev;
2262 	struct device *device = NULL;
2263 	int ret;
2264 
2265 	cdev = cdev_alloc();
2266 	if (!cdev) {
2267 		pr_err("Could not allocate cdev for minor %d, %s\n",
2268 		       minor, name);
2269 		ret = -ENOMEM;
2270 		goto done;
2271 	}
2272 
2273 	cdev->owner = THIS_MODULE;
2274 	cdev->ops = fops;
2275 	kobject_set_name(&cdev->kobj, name);
2276 
2277 	ret = cdev_add(cdev, dev, 1);
2278 	if (ret < 0) {
2279 		pr_err("Could not add cdev for minor %d, %s (err %d)\n",
2280 		       minor, name, -ret);
2281 		goto err_cdev;
2282 	}
2283 
2284 	device = device_create(qib_class, NULL, dev, NULL, "%s", name);
2285 	if (!IS_ERR(device))
2286 		goto done;
2287 	ret = PTR_ERR(device);
2288 	device = NULL;
2289 	pr_err("Could not create device for minor %d, %s (err %d)\n",
2290 	       minor, name, -ret);
2291 err_cdev:
2292 	cdev_del(cdev);
2293 	cdev = NULL;
2294 done:
2295 	*cdevp = cdev;
2296 	*devp = device;
2297 	return ret;
2298 }
2299 
2300 void qib_cdev_cleanup(struct cdev **cdevp, struct device **devp)
2301 {
2302 	struct device *device = *devp;
2303 
2304 	if (device) {
2305 		device_unregister(device);
2306 		*devp = NULL;
2307 	}
2308 
2309 	if (*cdevp) {
2310 		cdev_del(*cdevp);
2311 		*cdevp = NULL;
2312 	}
2313 }
2314 
2315 static struct cdev *wildcard_cdev;
2316 static struct device *wildcard_device;
2317 
2318 int __init qib_dev_init(void)
2319 {
2320 	int ret;
2321 
2322 	ret = alloc_chrdev_region(&qib_dev, 0, QIB_NMINORS, QIB_DRV_NAME);
2323 	if (ret < 0) {
2324 		pr_err("Could not allocate chrdev region (err %d)\n", -ret);
2325 		goto done;
2326 	}
2327 
2328 	qib_class = class_create("ipath");
2329 	if (IS_ERR(qib_class)) {
2330 		ret = PTR_ERR(qib_class);
2331 		pr_err("Could not create device class (err %d)\n", -ret);
2332 		unregister_chrdev_region(qib_dev, QIB_NMINORS);
2333 	}
2334 
2335 done:
2336 	return ret;
2337 }
2338 
2339 void qib_dev_cleanup(void)
2340 {
2341 	if (qib_class) {
2342 		class_destroy(qib_class);
2343 		qib_class = NULL;
2344 	}
2345 
2346 	unregister_chrdev_region(qib_dev, QIB_NMINORS);
2347 }
2348 
2349 static atomic_t user_count = ATOMIC_INIT(0);
2350 
2351 static void qib_user_remove(struct qib_devdata *dd)
2352 {
2353 	if (atomic_dec_return(&user_count) == 0)
2354 		qib_cdev_cleanup(&wildcard_cdev, &wildcard_device);
2355 
2356 	qib_cdev_cleanup(&dd->user_cdev, &dd->user_device);
2357 }
2358 
2359 static int qib_user_add(struct qib_devdata *dd)
2360 {
2361 	char name[10];
2362 	int ret;
2363 
2364 	if (atomic_inc_return(&user_count) == 1) {
2365 		ret = qib_cdev_init(0, "ipath", &qib_file_ops,
2366 				    &wildcard_cdev, &wildcard_device);
2367 		if (ret)
2368 			goto done;
2369 	}
2370 
2371 	snprintf(name, sizeof(name), "ipath%d", dd->unit);
2372 	ret = qib_cdev_init(dd->unit + 1, name, &qib_file_ops,
2373 			    &dd->user_cdev, &dd->user_device);
2374 	if (ret)
2375 		qib_user_remove(dd);
2376 done:
2377 	return ret;
2378 }
2379 
2380 /*
2381  * Create per-unit files in /dev
2382  */
2383 int qib_device_create(struct qib_devdata *dd)
2384 {
2385 	int r, ret;
2386 
2387 	r = qib_user_add(dd);
2388 	ret = qib_diag_add(dd);
2389 	if (r && !ret)
2390 		ret = r;
2391 	return ret;
2392 }
2393 
2394 /*
2395  * Remove per-unit files in /dev
2396  * void, core kernel returns no errors for this stuff
2397  */
2398 void qib_device_remove(struct qib_devdata *dd)
2399 {
2400 	qib_user_remove(dd);
2401 	qib_diag_remove(dd);
2402 }
2403