summaryrefslogtreecommitdiff
path: root/mm/gup_test.c
blob: 8ae7307a1bb6e64e46f98f831450bdcec554bc12 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/uaccess.h>
#include <linux/ktime.h>
#include <linux/debugfs.h>
#include <linux/highmem.h>
#include "gup_test.h"

static void put_back_pages(unsigned int cmd, struct page **pages,
			   unsigned long nr_pages, unsigned int gup_test_flags)
{
	unsigned long i;

	switch (cmd) {
	case GUP_FAST_BENCHMARK:
	case GUP_BASIC_TEST:
		for (i = 0; i < nr_pages; i++)
			put_page(pages[i]);
		break;

	case PIN_FAST_BENCHMARK:
	case PIN_BASIC_TEST:
	case PIN_LONGTERM_BENCHMARK:
		unpin_user_pages(pages, nr_pages);
		break;
	case DUMP_USER_PAGES_TEST:
		if (gup_test_flags & GUP_TEST_FLAG_DUMP_PAGES_USE_PIN) {
			unpin_user_pages(pages, nr_pages);
		} else {
			for (i = 0; i < nr_pages; i++)
				put_page(pages[i]);

		}
		break;
	}
}

static void verify_dma_pinned(unsigned int cmd, struct page **pages,
			      unsigned long nr_pages)
{
	unsigned long i;
	struct page *page;

	switch (cmd) {
	case PIN_FAST_BENCHMARK:
	case PIN_BASIC_TEST:
	case PIN_LONGTERM_BENCHMARK:
		for (i = 0; i < nr_pages; i++) {
			page = pages[i];
			if (WARN(!page_maybe_dma_pinned(page),
				 "pages[%lu] is NOT dma-pinned\n", i)) {

				dump_page(page, "gup_test failure");
				break;
			} else if (cmd == PIN_LONGTERM_BENCHMARK &&
				WARN(!is_longterm_pinnable_page(page),
				     "pages[%lu] is NOT pinnable but pinned\n",
				     i)) {
				dump_page(page, "gup_test failure");
				break;
			}
		}
		break;
	}
}

static void dump_pages_test(struct gup_test *gup, struct page **pages,
			    unsigned long nr_pages)
{
	unsigned int index_to_dump;
	unsigned int i;

	/*
	 * Zero out any user-supplied page index that is out of range. Remember:
	 * .which_pages[] contains a 1-based set of page indices.
	 */
	for (i = 0; i < GUP_TEST_MAX_PAGES_TO_DUMP; i++) {
		if (gup->which_pages[i] > nr_pages) {
			pr_warn("ZEROING due to out of range: .which_pages[%u]: %u\n",
				i, gup->which_pages[i]);
			gup->which_pages[i] = 0;
		}
	}

	for (i = 0; i < GUP_TEST_MAX_PAGES_TO_DUMP; i++) {
		index_to_dump = gup->which_pages[i];

		if (index_to_dump) {
			index_to_dump--; // Decode from 1-based, to 0-based
			pr_info("---- page #%u, starting from user virt addr: 0x%llx\n",
				index_to_dump, gup->addr);
			dump_page(pages[index_to_dump],
				  "gup_test: dump_pages() test");
		}
	}
}

static int __gup_test_ioctl(unsigned int cmd,
		struct gup_test *gup)
{
	ktime_t start_time, end_time;
	unsigned long i, nr_pages, addr, next;
	long nr;
	struct page **pages;
	int ret = 0;
	bool needs_mmap_lock =
		cmd != GUP_FAST_BENCHMARK && cmd != PIN_FAST_BENCHMARK;

	if (gup->size > ULONG_MAX)
		return -EINVAL;

	nr_pages = gup->size / PAGE_SIZE;
	pages = kvcalloc(nr_pages, sizeof(void *), GFP_KERNEL);
	if (!pages)
		return -ENOMEM;

	if (needs_mmap_lock && mmap_read_lock_killable(current->mm)) {
		ret = -EINTR;
		goto free_pages;
	}

	i = 0;
	nr = gup->nr_pages_per_call;
	start_time = ktime_get();
	for (addr = gup->addr; addr < gup->addr + gup->size; addr = next) {
		if (nr != gup->nr_pages_per_call)
			break;

		next = addr + nr * PAGE_SIZE;
		if (next > gup->addr + gup->size) {
			next = gup->addr + gup->size;
			nr = (next - addr) / PAGE_SIZE;
		}

		switch (cmd) {
		case GUP_FAST_BENCHMARK:
			nr = get_user_pages_fast(addr, nr, gup->gup_flags,
						 pages + i);
			break;
		case GUP_BASIC_TEST:
			nr = get_user_pages(addr, nr, gup->gup_flags, pages + i,
					    NULL);
			break;
		case PIN_FAST_BENCHMARK:
			nr = pin_user_pages_fast(addr, nr, gup->gup_flags,
						 pages + i);
			break;
		case PIN_BASIC_TEST:
			nr = pin_user_pages(addr, nr, gup->gup_flags, pages + i,
					    NULL);
			break;
		case PIN_LONGTERM_BENCHMARK:
			nr = pin_user_pages(addr, nr,
					    gup->gup_flags | FOLL_LONGTERM,
					    pages + i, NULL);
			break;
		case DUMP_USER_PAGES_TEST:
			if (gup->test_flags & GUP_TEST_FLAG_DUMP_PAGES_USE_PIN)
				nr = pin_user_pages(addr, nr, gup->gup_flags,
						    pages + i, NULL);
			else
				nr = get_user_pages(addr, nr, gup->gup_flags,
						    pages + i, NULL);
			break;
		default:
			ret = -EINVAL;
			goto unlock;
		}

		if (nr <= 0)
			break;
		i += nr;
	}
	end_time = ktime_get();

	/* Shifting the meaning of nr_pages: now it is actual number pinned: */
	nr_pages = i;

	gup->get_delta_usec = ktime_us_delta(end_time, start_time);
	gup->size = addr - gup->addr;

	/*
	 * Take an un-benchmark-timed moment to verify DMA pinned
	 * state: print a warning if any non-dma-pinned pages are found:
	 */
	verify_dma_pinned(cmd, pages, nr_pages);

	if (cmd == DUMP_USER_PAGES_TEST)
		dump_pages_test(gup, pages, nr_pages);

	start_time = ktime_get();

	put_back_pages(cmd, pages, nr_pages, gup->test_flags);

	end_time = ktime_get();
	gup->put_delta_usec = ktime_us_delta(end_time, start_time);

unlock:
	if (needs_mmap_lock)
		mmap_read_unlock(current->mm);
free_pages:
	kvfree(pages);
	return ret;
}

static DEFINE_MUTEX(pin_longterm_test_mutex);
static struct page **pin_longterm_test_pages;
static unsigned long pin_longterm_test_nr_pages;

static inline void pin_longterm_test_stop(void)
{
	if (pin_longterm_test_pages) {
		if (pin_longterm_test_nr_pages)
			unpin_user_pages(pin_longterm_test_pages,
					 pin_longterm_test_nr_pages);
		kvfree(pin_longterm_test_pages);
		pin_longterm_test_pages = NULL;
		pin_longterm_test_nr_pages = 0;
	}
}

static inline int pin_longterm_test_start(unsigned long arg)
{
	long nr_pages, cur_pages, addr, remaining_pages;
	int gup_flags = FOLL_LONGTERM;
	struct pin_longterm_test args;
	struct page **pages;
	int ret = 0;
	bool fast;

	if (pin_longterm_test_pages)
		return -EINVAL;

	if (copy_from_user(&args, (void __user *)arg, sizeof(args)))
		return -EFAULT;

	if (args.flags &
	    ~(PIN_LONGTERM_TEST_FLAG_USE_WRITE|PIN_LONGTERM_TEST_FLAG_USE_FAST))
		return -EINVAL;
	if (!IS_ALIGNED(args.addr | args.size, PAGE_SIZE))
		return -EINVAL;
	if (args.size > LONG_MAX)
		return -EINVAL;
	nr_pages = args.size / PAGE_SIZE;
	if (!nr_pages)
		return -EINVAL;

	pages = kvcalloc(nr_pages, sizeof(void *), GFP_KERNEL);
	if (!pages)
		return -ENOMEM;

	if (args.flags & PIN_LONGTERM_TEST_FLAG_USE_WRITE)
		gup_flags |= FOLL_WRITE;
	fast = !!(args.flags & PIN_LONGTERM_TEST_FLAG_USE_FAST);

	if (!fast && mmap_read_lock_killable(current->mm)) {
		kvfree(pages);
		return -EINTR;
	}

	pin_longterm_test_pages = pages;
	pin_longterm_test_nr_pages = 0;

	while (nr_pages - pin_longterm_test_nr_pages) {
		remaining_pages = nr_pages - pin_longterm_test_nr_pages;
		addr = args.addr + pin_longterm_test_nr_pages * PAGE_SIZE;

		if (fast)
			cur_pages = pin_user_pages_fast(addr, remaining_pages,
							gup_flags, pages);
		else
			cur_pages = pin_user_pages(addr, remaining_pages,
						   gup_flags, pages, NULL);
		if (cur_pages < 0) {
			pin_longterm_test_stop();
			ret = cur_pages;
			break;
		}
		pin_longterm_test_nr_pages += cur_pages;
		pages += cur_pages;
	}

	if (!fast)
		mmap_read_unlock(current->mm);
	return ret;
}

static inline int pin_longterm_test_read(unsigned long arg)
{
	__u64 user_addr;
	unsigned long i;

	if (!pin_longterm_test_pages)
		return -EINVAL;

	if (copy_from_user(&user_addr, (void __user *)arg, sizeof(user_addr)))
		return -EFAULT;

	for (i = 0; i < pin_longterm_test_nr_pages; i++) {
		void *addr = kmap_local_page(pin_longterm_test_pages[i]);
		unsigned long ret;

		ret = copy_to_user((void __user *)(unsigned long)user_addr, addr,
				   PAGE_SIZE);
		kunmap_local(addr);
		if (ret)
			return -EFAULT;
		user_addr += PAGE_SIZE;
	}
	return 0;
}

static long pin_longterm_test_ioctl(struct file *filep, unsigned int cmd,
				    unsigned long arg)
{
	int ret = -EINVAL;

	if (mutex_lock_killable(&pin_longterm_test_mutex))
		return -EINTR;

	switch (cmd) {
	case PIN_LONGTERM_TEST_START:
		ret = pin_longterm_test_start(arg);
		break;
	case PIN_LONGTERM_TEST_STOP:
		pin_longterm_test_stop();
		ret = 0;
		break;
	case PIN_LONGTERM_TEST_READ:
		ret = pin_longterm_test_read(arg);
		break;
	}

	mutex_unlock(&pin_longterm_test_mutex);
	return ret;
}

static long gup_test_ioctl(struct file *filep, unsigned int cmd,
		unsigned long arg)
{
	struct gup_test gup;
	int ret;

	switch (cmd) {
	case GUP_FAST_BENCHMARK:
	case PIN_FAST_BENCHMARK:
	case PIN_LONGTERM_BENCHMARK:
	case GUP_BASIC_TEST:
	case PIN_BASIC_TEST:
	case DUMP_USER_PAGES_TEST:
		break;
	case PIN_LONGTERM_TEST_START:
	case PIN_LONGTERM_TEST_STOP:
	case PIN_LONGTERM_TEST_READ:
		return pin_longterm_test_ioctl(filep, cmd, arg);
	default:
		return -EINVAL;
	}

	if (copy_from_user(&gup, (void __user *)arg, sizeof(gup)))
		return -EFAULT;

	ret = __gup_test_ioctl(cmd, &gup);
	if (ret)
		return ret;

	if (copy_to_user((void __user *)arg, &gup, sizeof(gup)))
		return -EFAULT;

	return 0;
}

static int gup_test_release(struct inode *inode, struct file *file)
{
	pin_longterm_test_stop();

	return 0;
}

static const struct file_operations gup_test_fops = {
	.open = nonseekable_open,
	.unlocked_ioctl = gup_test_ioctl,
	.release = gup_test_release,
};

static int __init gup_test_init(void)
{
	debugfs_create_file_unsafe("gup_test", 0600, NULL, NULL,
				   &gup_test_fops);

	return 0;
}

late_initcall(gup_test_init);