xref: /openbmc/linux/mm/gup_test.c (revision 906a76cc)
1 #include <linux/kernel.h>
2 #include <linux/mm.h>
3 #include <linux/slab.h>
4 #include <linux/uaccess.h>
5 #include <linux/ktime.h>
6 #include <linux/debugfs.h>
7 #include <linux/highmem.h>
8 #include "gup_test.h"
9 
10 static void put_back_pages(unsigned int cmd, struct page **pages,
11 			   unsigned long nr_pages, unsigned int gup_test_flags)
12 {
13 	unsigned long i;
14 
15 	switch (cmd) {
16 	case GUP_FAST_BENCHMARK:
17 	case GUP_BASIC_TEST:
18 		for (i = 0; i < nr_pages; i++)
19 			put_page(pages[i]);
20 		break;
21 
22 	case PIN_FAST_BENCHMARK:
23 	case PIN_BASIC_TEST:
24 	case PIN_LONGTERM_BENCHMARK:
25 		unpin_user_pages(pages, nr_pages);
26 		break;
27 	case DUMP_USER_PAGES_TEST:
28 		if (gup_test_flags & GUP_TEST_FLAG_DUMP_PAGES_USE_PIN) {
29 			unpin_user_pages(pages, nr_pages);
30 		} else {
31 			for (i = 0; i < nr_pages; i++)
32 				put_page(pages[i]);
33 
34 		}
35 		break;
36 	}
37 }
38 
39 static void verify_dma_pinned(unsigned int cmd, struct page **pages,
40 			      unsigned long nr_pages)
41 {
42 	unsigned long i;
43 	struct page *page;
44 
45 	switch (cmd) {
46 	case PIN_FAST_BENCHMARK:
47 	case PIN_BASIC_TEST:
48 	case PIN_LONGTERM_BENCHMARK:
49 		for (i = 0; i < nr_pages; i++) {
50 			page = pages[i];
51 			if (WARN(!page_maybe_dma_pinned(page),
52 				 "pages[%lu] is NOT dma-pinned\n", i)) {
53 
54 				dump_page(page, "gup_test failure");
55 				break;
56 			} else if (cmd == PIN_LONGTERM_BENCHMARK &&
57 				WARN(!is_longterm_pinnable_page(page),
58 				     "pages[%lu] is NOT pinnable but pinned\n",
59 				     i)) {
60 				dump_page(page, "gup_test failure");
61 				break;
62 			}
63 		}
64 		break;
65 	}
66 }
67 
68 static void dump_pages_test(struct gup_test *gup, struct page **pages,
69 			    unsigned long nr_pages)
70 {
71 	unsigned int index_to_dump;
72 	unsigned int i;
73 
74 	/*
75 	 * Zero out any user-supplied page index that is out of range. Remember:
76 	 * .which_pages[] contains a 1-based set of page indices.
77 	 */
78 	for (i = 0; i < GUP_TEST_MAX_PAGES_TO_DUMP; i++) {
79 		if (gup->which_pages[i] > nr_pages) {
80 			pr_warn("ZEROING due to out of range: .which_pages[%u]: %u\n",
81 				i, gup->which_pages[i]);
82 			gup->which_pages[i] = 0;
83 		}
84 	}
85 
86 	for (i = 0; i < GUP_TEST_MAX_PAGES_TO_DUMP; i++) {
87 		index_to_dump = gup->which_pages[i];
88 
89 		if (index_to_dump) {
90 			index_to_dump--; // Decode from 1-based, to 0-based
91 			pr_info("---- page #%u, starting from user virt addr: 0x%llx\n",
92 				index_to_dump, gup->addr);
93 			dump_page(pages[index_to_dump],
94 				  "gup_test: dump_pages() test");
95 		}
96 	}
97 }
98 
99 static int __gup_test_ioctl(unsigned int cmd,
100 		struct gup_test *gup)
101 {
102 	ktime_t start_time, end_time;
103 	unsigned long i, nr_pages, addr, next;
104 	long nr;
105 	struct page **pages;
106 	int ret = 0;
107 	bool needs_mmap_lock =
108 		cmd != GUP_FAST_BENCHMARK && cmd != PIN_FAST_BENCHMARK;
109 
110 	if (gup->size > ULONG_MAX)
111 		return -EINVAL;
112 
113 	nr_pages = gup->size / PAGE_SIZE;
114 	pages = kvcalloc(nr_pages, sizeof(void *), GFP_KERNEL);
115 	if (!pages)
116 		return -ENOMEM;
117 
118 	if (needs_mmap_lock && mmap_read_lock_killable(current->mm)) {
119 		ret = -EINTR;
120 		goto free_pages;
121 	}
122 
123 	i = 0;
124 	nr = gup->nr_pages_per_call;
125 	start_time = ktime_get();
126 	for (addr = gup->addr; addr < gup->addr + gup->size; addr = next) {
127 		if (nr != gup->nr_pages_per_call)
128 			break;
129 
130 		next = addr + nr * PAGE_SIZE;
131 		if (next > gup->addr + gup->size) {
132 			next = gup->addr + gup->size;
133 			nr = (next - addr) / PAGE_SIZE;
134 		}
135 
136 		switch (cmd) {
137 		case GUP_FAST_BENCHMARK:
138 			nr = get_user_pages_fast(addr, nr, gup->gup_flags,
139 						 pages + i);
140 			break;
141 		case GUP_BASIC_TEST:
142 			nr = get_user_pages(addr, nr, gup->gup_flags, pages + i,
143 					    NULL);
144 			break;
145 		case PIN_FAST_BENCHMARK:
146 			nr = pin_user_pages_fast(addr, nr, gup->gup_flags,
147 						 pages + i);
148 			break;
149 		case PIN_BASIC_TEST:
150 			nr = pin_user_pages(addr, nr, gup->gup_flags, pages + i,
151 					    NULL);
152 			break;
153 		case PIN_LONGTERM_BENCHMARK:
154 			nr = pin_user_pages(addr, nr,
155 					    gup->gup_flags | FOLL_LONGTERM,
156 					    pages + i, NULL);
157 			break;
158 		case DUMP_USER_PAGES_TEST:
159 			if (gup->test_flags & GUP_TEST_FLAG_DUMP_PAGES_USE_PIN)
160 				nr = pin_user_pages(addr, nr, gup->gup_flags,
161 						    pages + i, NULL);
162 			else
163 				nr = get_user_pages(addr, nr, gup->gup_flags,
164 						    pages + i, NULL);
165 			break;
166 		default:
167 			ret = -EINVAL;
168 			goto unlock;
169 		}
170 
171 		if (nr <= 0)
172 			break;
173 		i += nr;
174 	}
175 	end_time = ktime_get();
176 
177 	/* Shifting the meaning of nr_pages: now it is actual number pinned: */
178 	nr_pages = i;
179 
180 	gup->get_delta_usec = ktime_us_delta(end_time, start_time);
181 	gup->size = addr - gup->addr;
182 
183 	/*
184 	 * Take an un-benchmark-timed moment to verify DMA pinned
185 	 * state: print a warning if any non-dma-pinned pages are found:
186 	 */
187 	verify_dma_pinned(cmd, pages, nr_pages);
188 
189 	if (cmd == DUMP_USER_PAGES_TEST)
190 		dump_pages_test(gup, pages, nr_pages);
191 
192 	start_time = ktime_get();
193 
194 	put_back_pages(cmd, pages, nr_pages, gup->test_flags);
195 
196 	end_time = ktime_get();
197 	gup->put_delta_usec = ktime_us_delta(end_time, start_time);
198 
199 unlock:
200 	if (needs_mmap_lock)
201 		mmap_read_unlock(current->mm);
202 free_pages:
203 	kvfree(pages);
204 	return ret;
205 }
206 
207 static DEFINE_MUTEX(pin_longterm_test_mutex);
208 static struct page **pin_longterm_test_pages;
209 static unsigned long pin_longterm_test_nr_pages;
210 
211 static inline void pin_longterm_test_stop(void)
212 {
213 	if (pin_longterm_test_pages) {
214 		if (pin_longterm_test_nr_pages)
215 			unpin_user_pages(pin_longterm_test_pages,
216 					 pin_longterm_test_nr_pages);
217 		kvfree(pin_longterm_test_pages);
218 		pin_longterm_test_pages = NULL;
219 		pin_longterm_test_nr_pages = 0;
220 	}
221 }
222 
223 static inline int pin_longterm_test_start(unsigned long arg)
224 {
225 	long nr_pages, cur_pages, addr, remaining_pages;
226 	int gup_flags = FOLL_LONGTERM;
227 	struct pin_longterm_test args;
228 	struct page **pages;
229 	int ret = 0;
230 	bool fast;
231 
232 	if (pin_longterm_test_pages)
233 		return -EINVAL;
234 
235 	if (copy_from_user(&args, (void __user *)arg, sizeof(args)))
236 		return -EFAULT;
237 
238 	if (args.flags &
239 	    ~(PIN_LONGTERM_TEST_FLAG_USE_WRITE|PIN_LONGTERM_TEST_FLAG_USE_FAST))
240 		return -EINVAL;
241 	if (!IS_ALIGNED(args.addr | args.size, PAGE_SIZE))
242 		return -EINVAL;
243 	if (args.size > LONG_MAX)
244 		return -EINVAL;
245 	nr_pages = args.size / PAGE_SIZE;
246 	if (!nr_pages)
247 		return -EINVAL;
248 
249 	pages = kvcalloc(nr_pages, sizeof(void *), GFP_KERNEL);
250 	if (!pages)
251 		return -ENOMEM;
252 
253 	if (args.flags & PIN_LONGTERM_TEST_FLAG_USE_WRITE)
254 		gup_flags |= FOLL_WRITE;
255 	fast = !!(args.flags & PIN_LONGTERM_TEST_FLAG_USE_FAST);
256 
257 	if (!fast && mmap_read_lock_killable(current->mm)) {
258 		kvfree(pages);
259 		return -EINTR;
260 	}
261 
262 	pin_longterm_test_pages = pages;
263 	pin_longterm_test_nr_pages = 0;
264 
265 	while (nr_pages - pin_longterm_test_nr_pages) {
266 		remaining_pages = nr_pages - pin_longterm_test_nr_pages;
267 		addr = args.addr + pin_longterm_test_nr_pages * PAGE_SIZE;
268 
269 		if (fast)
270 			cur_pages = pin_user_pages_fast(addr, remaining_pages,
271 							gup_flags, pages);
272 		else
273 			cur_pages = pin_user_pages(addr, remaining_pages,
274 						   gup_flags, pages, NULL);
275 		if (cur_pages < 0) {
276 			pin_longterm_test_stop();
277 			ret = cur_pages;
278 			break;
279 		}
280 		pin_longterm_test_nr_pages += cur_pages;
281 		pages += cur_pages;
282 	}
283 
284 	if (!fast)
285 		mmap_read_unlock(current->mm);
286 	return ret;
287 }
288 
289 static inline int pin_longterm_test_read(unsigned long arg)
290 {
291 	__u64 user_addr;
292 	unsigned long i;
293 
294 	if (!pin_longterm_test_pages)
295 		return -EINVAL;
296 
297 	if (copy_from_user(&user_addr, (void __user *)arg, sizeof(user_addr)))
298 		return -EFAULT;
299 
300 	for (i = 0; i < pin_longterm_test_nr_pages; i++) {
301 		void *addr = kmap_local_page(pin_longterm_test_pages[i]);
302 		unsigned long ret;
303 
304 		ret = copy_to_user((void __user *)(unsigned long)user_addr, addr,
305 				   PAGE_SIZE);
306 		kunmap_local(addr);
307 		if (ret)
308 			return -EFAULT;
309 		user_addr += PAGE_SIZE;
310 	}
311 	return 0;
312 }
313 
314 static long pin_longterm_test_ioctl(struct file *filep, unsigned int cmd,
315 				    unsigned long arg)
316 {
317 	int ret = -EINVAL;
318 
319 	if (mutex_lock_killable(&pin_longterm_test_mutex))
320 		return -EINTR;
321 
322 	switch (cmd) {
323 	case PIN_LONGTERM_TEST_START:
324 		ret = pin_longterm_test_start(arg);
325 		break;
326 	case PIN_LONGTERM_TEST_STOP:
327 		pin_longterm_test_stop();
328 		ret = 0;
329 		break;
330 	case PIN_LONGTERM_TEST_READ:
331 		ret = pin_longterm_test_read(arg);
332 		break;
333 	}
334 
335 	mutex_unlock(&pin_longterm_test_mutex);
336 	return ret;
337 }
338 
339 static long gup_test_ioctl(struct file *filep, unsigned int cmd,
340 		unsigned long arg)
341 {
342 	struct gup_test gup;
343 	int ret;
344 
345 	switch (cmd) {
346 	case GUP_FAST_BENCHMARK:
347 	case PIN_FAST_BENCHMARK:
348 	case PIN_LONGTERM_BENCHMARK:
349 	case GUP_BASIC_TEST:
350 	case PIN_BASIC_TEST:
351 	case DUMP_USER_PAGES_TEST:
352 		break;
353 	case PIN_LONGTERM_TEST_START:
354 	case PIN_LONGTERM_TEST_STOP:
355 	case PIN_LONGTERM_TEST_READ:
356 		return pin_longterm_test_ioctl(filep, cmd, arg);
357 	default:
358 		return -EINVAL;
359 	}
360 
361 	if (copy_from_user(&gup, (void __user *)arg, sizeof(gup)))
362 		return -EFAULT;
363 
364 	ret = __gup_test_ioctl(cmd, &gup);
365 	if (ret)
366 		return ret;
367 
368 	if (copy_to_user((void __user *)arg, &gup, sizeof(gup)))
369 		return -EFAULT;
370 
371 	return 0;
372 }
373 
374 static int gup_test_release(struct inode *inode, struct file *file)
375 {
376 	pin_longterm_test_stop();
377 
378 	return 0;
379 }
380 
381 static const struct file_operations gup_test_fops = {
382 	.open = nonseekable_open,
383 	.unlocked_ioctl = gup_test_ioctl,
384 	.compat_ioctl = compat_ptr_ioctl,
385 	.release = gup_test_release,
386 };
387 
388 static int __init gup_test_init(void)
389 {
390 	debugfs_create_file_unsafe("gup_test", 0600, NULL, NULL,
391 				   &gup_test_fops);
392 
393 	return 0;
394 }
395 
396 late_initcall(gup_test_init);
397