1/*
2 * Copyright (c) 2005 Topspin Communications.  All rights reserved.
3 * Copyright (c) 2005 Mellanox Technologies. All rights reserved.
4 * Copyright (c) 2013 Cisco Systems.  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 * 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/mm.h>
36#include <linux/dma-mapping.h>
37#include <linux/sched/signal.h>
38#include <linux/sched/mm.h>
39#include <linux/hugetlb.h>
40#include <linux/iommu.h>
41#include <linux/workqueue.h>
42#include <linux/list.h>
43#include <linux/pci.h>
44#include <rdma/ib_verbs.h>
45
46#include "usnic_log.h"
47#include "usnic_uiom.h"
48#include "usnic_uiom_interval_tree.h"
49
50#define USNIC_UIOM_PAGE_CHUNK						\
51	((PAGE_SIZE - offsetof(struct usnic_uiom_chunk, page_list))	/\
52	((void *) &((struct usnic_uiom_chunk *) 0)->page_list[1] -	\
53	(void *) &((struct usnic_uiom_chunk *) 0)->page_list[0]))
54
55static int usnic_uiom_dma_fault(struct iommu_domain *domain,
56				struct device *dev,
57				unsigned long iova, int flags,
58				void *token)
59{
60	usnic_err("Device %s iommu fault domain 0x%pK va 0x%lx flags 0x%x\n",
61		dev_name(dev),
62		domain, iova, flags);
63	return -ENOSYS;
64}
65
66static void usnic_uiom_put_pages(struct list_head *chunk_list, int dirty)
67{
68	struct usnic_uiom_chunk *chunk, *tmp;
69	struct page *page;
70	struct scatterlist *sg;
71	int i;
72	dma_addr_t pa;
73
74	list_for_each_entry_safe(chunk, tmp, chunk_list, list) {
75		for_each_sg(chunk->page_list, sg, chunk->nents, i) {
76			page = sg_page(sg);
77			pa = sg_phys(sg);
78			unpin_user_pages_dirty_lock(&page, 1, dirty);
79			usnic_dbg("pa: %pa\n", &pa);
80		}
81		kfree(chunk);
82	}
83}
84
85static int usnic_uiom_get_pages(unsigned long addr, size_t size, int writable,
86				int dmasync, struct usnic_uiom_reg *uiomr)
87{
88	struct list_head *chunk_list = &uiomr->chunk_list;
89	struct page **page_list;
90	struct scatterlist *sg;
91	struct usnic_uiom_chunk *chunk;
92	unsigned long locked;
93	unsigned long lock_limit;
94	unsigned long cur_base;
95	unsigned long npages;
96	int ret;
97	int off;
98	int i;
99	int flags;
100	dma_addr_t pa;
101	unsigned int gup_flags;
102	struct mm_struct *mm;
103
104	/*
105	 * If the combination of the addr and size requested for this memory
106	 * region causes an integer overflow, return error.
107	 */
108	if (((addr + size) < addr) || PAGE_ALIGN(addr + size) < (addr + size))
109		return -EINVAL;
110
111	if (!size)
112		return -EINVAL;
113
114	if (!can_do_mlock())
115		return -EPERM;
116
117	INIT_LIST_HEAD(chunk_list);
118
119	page_list = (struct page **) __get_free_page(GFP_KERNEL);
120	if (!page_list)
121		return -ENOMEM;
122
123	npages = PAGE_ALIGN(size + (addr & ~PAGE_MASK)) >> PAGE_SHIFT;
124
125	uiomr->owning_mm = mm = current->mm;
126	mmap_read_lock(mm);
127
128	locked = atomic64_add_return(npages, &current->mm->pinned_vm);
129	lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
130
131	if ((locked > lock_limit) && !capable(CAP_IPC_LOCK)) {
132		ret = -ENOMEM;
133		goto out;
134	}
135
136	flags = IOMMU_READ | IOMMU_CACHE;
137	flags |= (writable) ? IOMMU_WRITE : 0;
138	gup_flags = FOLL_WRITE;
139	gup_flags |= (writable) ? 0 : FOLL_FORCE;
140	cur_base = addr & PAGE_MASK;
141	ret = 0;
142
143	while (npages) {
144		ret = pin_user_pages(cur_base,
145				     min_t(unsigned long, npages,
146				     PAGE_SIZE / sizeof(struct page *)),
147				     gup_flags | FOLL_LONGTERM,
148				     page_list, NULL);
149
150		if (ret < 0)
151			goto out;
152
153		npages -= ret;
154		off = 0;
155
156		while (ret) {
157			chunk = kmalloc(struct_size(chunk, page_list,
158					min_t(int, ret, USNIC_UIOM_PAGE_CHUNK)),
159					GFP_KERNEL);
160			if (!chunk) {
161				ret = -ENOMEM;
162				goto out;
163			}
164
165			chunk->nents = min_t(int, ret, USNIC_UIOM_PAGE_CHUNK);
166			sg_init_table(chunk->page_list, chunk->nents);
167			for_each_sg(chunk->page_list, sg, chunk->nents, i) {
168				sg_set_page(sg, page_list[i + off],
169						PAGE_SIZE, 0);
170				pa = sg_phys(sg);
171				usnic_dbg("va: 0x%lx pa: %pa\n",
172						cur_base + i*PAGE_SIZE, &pa);
173			}
174			cur_base += chunk->nents * PAGE_SIZE;
175			ret -= chunk->nents;
176			off += chunk->nents;
177			list_add_tail(&chunk->list, chunk_list);
178		}
179
180		ret = 0;
181	}
182
183out:
184	if (ret < 0) {
185		usnic_uiom_put_pages(chunk_list, 0);
186		atomic64_sub(npages, &current->mm->pinned_vm);
187	} else
188		mmgrab(uiomr->owning_mm);
189
190	mmap_read_unlock(mm);
191	free_page((unsigned long) page_list);
192	return ret;
193}
194
195static void usnic_uiom_unmap_sorted_intervals(struct list_head *intervals,
196						struct usnic_uiom_pd *pd)
197{
198	struct usnic_uiom_interval_node *interval, *tmp;
199	long unsigned va, size;
200
201	list_for_each_entry_safe(interval, tmp, intervals, link) {
202		va = interval->start << PAGE_SHIFT;
203		size = ((interval->last - interval->start) + 1) << PAGE_SHIFT;
204		while (size > 0) {
205			/* Workaround for RH 970401 */
206			usnic_dbg("va 0x%lx size 0x%lx", va, PAGE_SIZE);
207			iommu_unmap(pd->domain, va, PAGE_SIZE);
208			va += PAGE_SIZE;
209			size -= PAGE_SIZE;
210		}
211	}
212}
213
214static void __usnic_uiom_reg_release(struct usnic_uiom_pd *pd,
215					struct usnic_uiom_reg *uiomr,
216					int dirty)
217{
218	int npages;
219	unsigned long vpn_start, vpn_last;
220	struct usnic_uiom_interval_node *interval, *tmp;
221	int writable = 0;
222	LIST_HEAD(rm_intervals);
223
224	npages = PAGE_ALIGN(uiomr->length + uiomr->offset) >> PAGE_SHIFT;
225	vpn_start = (uiomr->va & PAGE_MASK) >> PAGE_SHIFT;
226	vpn_last = vpn_start + npages - 1;
227
228	spin_lock(&pd->lock);
229	usnic_uiom_remove_interval(&pd->root, vpn_start,
230					vpn_last, &rm_intervals);
231	usnic_uiom_unmap_sorted_intervals(&rm_intervals, pd);
232
233	list_for_each_entry_safe(interval, tmp, &rm_intervals, link) {
234		if (interval->flags & IOMMU_WRITE)
235			writable = 1;
236		list_del(&interval->link);
237		kfree(interval);
238	}
239
240	usnic_uiom_put_pages(&uiomr->chunk_list, dirty & writable);
241	spin_unlock(&pd->lock);
242}
243
244static int usnic_uiom_map_sorted_intervals(struct list_head *intervals,
245						struct usnic_uiom_reg *uiomr)
246{
247	int i, err;
248	size_t size;
249	struct usnic_uiom_chunk *chunk;
250	struct usnic_uiom_interval_node *interval_node;
251	dma_addr_t pa;
252	dma_addr_t pa_start = 0;
253	dma_addr_t pa_end = 0;
254	long int va_start = -EINVAL;
255	struct usnic_uiom_pd *pd = uiomr->pd;
256	long int va = uiomr->va & PAGE_MASK;
257	int flags = IOMMU_READ | IOMMU_CACHE;
258
259	flags |= (uiomr->writable) ? IOMMU_WRITE : 0;
260	chunk = list_first_entry(&uiomr->chunk_list, struct usnic_uiom_chunk,
261									list);
262	list_for_each_entry(interval_node, intervals, link) {
263iter_chunk:
264		for (i = 0; i < chunk->nents; i++, va += PAGE_SIZE) {
265			pa = sg_phys(&chunk->page_list[i]);
266			if ((va >> PAGE_SHIFT) < interval_node->start)
267				continue;
268
269			if ((va >> PAGE_SHIFT) == interval_node->start) {
270				/* First page of the interval */
271				va_start = va;
272				pa_start = pa;
273				pa_end = pa;
274			}
275
276			WARN_ON(va_start == -EINVAL);
277
278			if ((pa_end + PAGE_SIZE != pa) &&
279					(pa != pa_start)) {
280				/* PAs are not contiguous */
281				size = pa_end - pa_start + PAGE_SIZE;
282				usnic_dbg("va 0x%lx pa %pa size 0x%zx flags 0x%x",
283					va_start, &pa_start, size, flags);
284				err = iommu_map_atomic(pd->domain, va_start,
285						       pa_start, size, flags);
286				if (err) {
287					usnic_err("Failed to map va 0x%lx pa %pa size 0x%zx with err %d\n",
288						va_start, &pa_start, size, err);
289					goto err_out;
290				}
291				va_start = va;
292				pa_start = pa;
293				pa_end = pa;
294			}
295
296			if ((va >> PAGE_SHIFT) == interval_node->last) {
297				/* Last page of the interval */
298				size = pa - pa_start + PAGE_SIZE;
299				usnic_dbg("va 0x%lx pa %pa size 0x%zx flags 0x%x\n",
300					va_start, &pa_start, size, flags);
301				err = iommu_map_atomic(pd->domain, va_start,
302						       pa_start, size, flags);
303				if (err) {
304					usnic_err("Failed to map va 0x%lx pa %pa size 0x%zx with err %d\n",
305						va_start, &pa_start, size, err);
306					goto err_out;
307				}
308				break;
309			}
310
311			if (pa != pa_start)
312				pa_end += PAGE_SIZE;
313		}
314
315		if (i == chunk->nents) {
316			/*
317			 * Hit last entry of the chunk,
318			 * hence advance to next chunk
319			 */
320			chunk = list_first_entry(&chunk->list,
321							struct usnic_uiom_chunk,
322							list);
323			goto iter_chunk;
324		}
325	}
326
327	return 0;
328
329err_out:
330	usnic_uiom_unmap_sorted_intervals(intervals, pd);
331	return err;
332}
333
334struct usnic_uiom_reg *usnic_uiom_reg_get(struct usnic_uiom_pd *pd,
335						unsigned long addr, size_t size,
336						int writable, int dmasync)
337{
338	struct usnic_uiom_reg *uiomr;
339	unsigned long va_base, vpn_start, vpn_last;
340	unsigned long npages;
341	int offset, err;
342	LIST_HEAD(sorted_diff_intervals);
343
344	/*
345	 * Intel IOMMU map throws an error if a translation entry is
346	 * changed from read to write.  This module may not unmap
347	 * and then remap the entry after fixing the permission
348	 * b/c this open up a small windows where hw DMA may page fault
349	 * Hence, make all entries to be writable.
350	 */
351	writable = 1;
352
353	va_base = addr & PAGE_MASK;
354	offset = addr & ~PAGE_MASK;
355	npages = PAGE_ALIGN(size + offset) >> PAGE_SHIFT;
356	vpn_start = (addr & PAGE_MASK) >> PAGE_SHIFT;
357	vpn_last = vpn_start + npages - 1;
358
359	uiomr = kmalloc(sizeof(*uiomr), GFP_KERNEL);
360	if (!uiomr)
361		return ERR_PTR(-ENOMEM);
362
363	uiomr->va = va_base;
364	uiomr->offset = offset;
365	uiomr->length = size;
366	uiomr->writable = writable;
367	uiomr->pd = pd;
368
369	err = usnic_uiom_get_pages(addr, size, writable, dmasync,
370				   uiomr);
371	if (err) {
372		usnic_err("Failed get_pages vpn [0x%lx,0x%lx] err %d\n",
373				vpn_start, vpn_last, err);
374		goto out_free_uiomr;
375	}
376
377	spin_lock(&pd->lock);
378	err = usnic_uiom_get_intervals_diff(vpn_start, vpn_last,
379						(writable) ? IOMMU_WRITE : 0,
380						IOMMU_WRITE,
381						&pd->root,
382						&sorted_diff_intervals);
383	if (err) {
384		usnic_err("Failed disjoint interval vpn [0x%lx,0x%lx] err %d\n",
385						vpn_start, vpn_last, err);
386		goto out_put_pages;
387	}
388
389	err = usnic_uiom_map_sorted_intervals(&sorted_diff_intervals, uiomr);
390	if (err) {
391		usnic_err("Failed map interval vpn [0x%lx,0x%lx] err %d\n",
392						vpn_start, vpn_last, err);
393		goto out_put_intervals;
394
395	}
396
397	err = usnic_uiom_insert_interval(&pd->root, vpn_start, vpn_last,
398					(writable) ? IOMMU_WRITE : 0);
399	if (err) {
400		usnic_err("Failed insert interval vpn [0x%lx,0x%lx] err %d\n",
401						vpn_start, vpn_last, err);
402		goto out_unmap_intervals;
403	}
404
405	usnic_uiom_put_interval_set(&sorted_diff_intervals);
406	spin_unlock(&pd->lock);
407
408	return uiomr;
409
410out_unmap_intervals:
411	usnic_uiom_unmap_sorted_intervals(&sorted_diff_intervals, pd);
412out_put_intervals:
413	usnic_uiom_put_interval_set(&sorted_diff_intervals);
414out_put_pages:
415	usnic_uiom_put_pages(&uiomr->chunk_list, 0);
416	spin_unlock(&pd->lock);
417	mmdrop(uiomr->owning_mm);
418out_free_uiomr:
419	kfree(uiomr);
420	return ERR_PTR(err);
421}
422
423static void __usnic_uiom_release_tail(struct usnic_uiom_reg *uiomr)
424{
425	mmdrop(uiomr->owning_mm);
426	kfree(uiomr);
427}
428
429static inline size_t usnic_uiom_num_pages(struct usnic_uiom_reg *uiomr)
430{
431	return PAGE_ALIGN(uiomr->length + uiomr->offset) >> PAGE_SHIFT;
432}
433
434void usnic_uiom_reg_release(struct usnic_uiom_reg *uiomr)
435{
436	__usnic_uiom_reg_release(uiomr->pd, uiomr, 1);
437
438	atomic64_sub(usnic_uiom_num_pages(uiomr), &uiomr->owning_mm->pinned_vm);
439	__usnic_uiom_release_tail(uiomr);
440}
441
442struct usnic_uiom_pd *usnic_uiom_alloc_pd(void)
443{
444	struct usnic_uiom_pd *pd;
445	void *domain;
446
447	pd = kzalloc(sizeof(*pd), GFP_KERNEL);
448	if (!pd)
449		return ERR_PTR(-ENOMEM);
450
451	pd->domain = domain = iommu_domain_alloc(&pci_bus_type);
452	if (!domain) {
453		usnic_err("Failed to allocate IOMMU domain");
454		kfree(pd);
455		return ERR_PTR(-ENOMEM);
456	}
457
458	iommu_set_fault_handler(pd->domain, usnic_uiom_dma_fault, NULL);
459
460	spin_lock_init(&pd->lock);
461	INIT_LIST_HEAD(&pd->devs);
462
463	return pd;
464}
465
466void usnic_uiom_dealloc_pd(struct usnic_uiom_pd *pd)
467{
468	iommu_domain_free(pd->domain);
469	kfree(pd);
470}
471
472int usnic_uiom_attach_dev_to_pd(struct usnic_uiom_pd *pd, struct device *dev)
473{
474	struct usnic_uiom_dev *uiom_dev;
475	int err;
476
477	uiom_dev = kzalloc(sizeof(*uiom_dev), GFP_ATOMIC);
478	if (!uiom_dev)
479		return -ENOMEM;
480	uiom_dev->dev = dev;
481
482	err = iommu_attach_device(pd->domain, dev);
483	if (err)
484		goto out_free_dev;
485
486	if (!iommu_capable(dev->bus, IOMMU_CAP_CACHE_COHERENCY)) {
487		usnic_err("IOMMU of %s does not support cache coherency\n",
488				dev_name(dev));
489		err = -EINVAL;
490		goto out_detach_device;
491	}
492
493	spin_lock(&pd->lock);
494	list_add_tail(&uiom_dev->link, &pd->devs);
495	pd->dev_cnt++;
496	spin_unlock(&pd->lock);
497
498	return 0;
499
500out_detach_device:
501	iommu_detach_device(pd->domain, dev);
502out_free_dev:
503	kfree(uiom_dev);
504	return err;
505}
506
507void usnic_uiom_detach_dev_from_pd(struct usnic_uiom_pd *pd, struct device *dev)
508{
509	struct usnic_uiom_dev *uiom_dev;
510	int found = 0;
511
512	spin_lock(&pd->lock);
513	list_for_each_entry(uiom_dev, &pd->devs, link) {
514		if (uiom_dev->dev == dev) {
515			found = 1;
516			break;
517		}
518	}
519
520	if (!found) {
521		usnic_err("Unable to free dev %s - not found\n",
522				dev_name(dev));
523		spin_unlock(&pd->lock);
524		return;
525	}
526
527	list_del(&uiom_dev->link);
528	pd->dev_cnt--;
529	spin_unlock(&pd->lock);
530
531	return iommu_detach_device(pd->domain, dev);
532}
533
534struct device **usnic_uiom_get_dev_list(struct usnic_uiom_pd *pd)
535{
536	struct usnic_uiom_dev *uiom_dev;
537	struct device **devs;
538	int i = 0;
539
540	spin_lock(&pd->lock);
541	devs = kcalloc(pd->dev_cnt + 1, sizeof(*devs), GFP_ATOMIC);
542	if (!devs) {
543		devs = ERR_PTR(-ENOMEM);
544		goto out;
545	}
546
547	list_for_each_entry(uiom_dev, &pd->devs, link) {
548		devs[i++] = uiom_dev->dev;
549	}
550out:
551	spin_unlock(&pd->lock);
552	return devs;
553}
554
555void usnic_uiom_free_dev_list(struct device **devs)
556{
557	kfree(devs);
558}
559
560int usnic_uiom_init(char *drv_name)
561{
562	if (!iommu_present(&pci_bus_type)) {
563		usnic_err("IOMMU required but not present or enabled.  USNIC QPs will not function w/o enabling IOMMU\n");
564		return -EPERM;
565	}
566
567	return 0;
568}
569