xref: /openbmc/linux/mm/gup_test.c (revision c9223a4a)
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 
put_back_pages(unsigned int cmd,struct page ** pages,unsigned long nr_pages,unsigned int gup_test_flags)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 
verify_dma_pinned(unsigned int cmd,struct page ** pages,unsigned long nr_pages)39 static void verify_dma_pinned(unsigned int cmd, struct page **pages,
40 			      unsigned long nr_pages)
41 {
42 	unsigned long i;
43 	struct folio *folio;
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 			folio = page_folio(pages[i]);
51 
52 			if (WARN(!folio_maybe_dma_pinned(folio),
53 				 "pages[%lu] is NOT dma-pinned\n", i)) {
54 
55 				dump_page(&folio->page, "gup_test failure");
56 				break;
57 			} else if (cmd == PIN_LONGTERM_BENCHMARK &&
58 				WARN(!folio_is_longterm_pinnable(folio),
59 				     "pages[%lu] is NOT pinnable but pinned\n",
60 				     i)) {
61 				dump_page(&folio->page, "gup_test failure");
62 				break;
63 			}
64 		}
65 		break;
66 	}
67 }
68 
dump_pages_test(struct gup_test * gup,struct page ** pages,unsigned long nr_pages)69 static void dump_pages_test(struct gup_test *gup, struct page **pages,
70 			    unsigned long nr_pages)
71 {
72 	unsigned int index_to_dump;
73 	unsigned int i;
74 
75 	/*
76 	 * Zero out any user-supplied page index that is out of range. Remember:
77 	 * .which_pages[] contains a 1-based set of page indices.
78 	 */
79 	for (i = 0; i < GUP_TEST_MAX_PAGES_TO_DUMP; i++) {
80 		if (gup->which_pages[i] > nr_pages) {
81 			pr_warn("ZEROING due to out of range: .which_pages[%u]: %u\n",
82 				i, gup->which_pages[i]);
83 			gup->which_pages[i] = 0;
84 		}
85 	}
86 
87 	for (i = 0; i < GUP_TEST_MAX_PAGES_TO_DUMP; i++) {
88 		index_to_dump = gup->which_pages[i];
89 
90 		if (index_to_dump) {
91 			index_to_dump--; // Decode from 1-based, to 0-based
92 			pr_info("---- page #%u, starting from user virt addr: 0x%llx\n",
93 				index_to_dump, gup->addr);
94 			dump_page(pages[index_to_dump],
95 				  "gup_test: dump_pages() test");
96 		}
97 	}
98 }
99 
__gup_test_ioctl(unsigned int cmd,struct gup_test * gup)100 static int __gup_test_ioctl(unsigned int cmd,
101 		struct gup_test *gup)
102 {
103 	ktime_t start_time, end_time;
104 	unsigned long i, nr_pages, addr, next;
105 	long nr;
106 	struct page **pages;
107 	int ret = 0;
108 	bool needs_mmap_lock =
109 		cmd != GUP_FAST_BENCHMARK && cmd != PIN_FAST_BENCHMARK;
110 
111 	if (gup->size > ULONG_MAX)
112 		return -EINVAL;
113 
114 	nr_pages = gup->size / PAGE_SIZE;
115 	pages = kvcalloc(nr_pages, sizeof(void *), GFP_KERNEL);
116 	if (!pages)
117 		return -ENOMEM;
118 
119 	if (needs_mmap_lock && mmap_read_lock_killable(current->mm)) {
120 		ret = -EINTR;
121 		goto free_pages;
122 	}
123 
124 	i = 0;
125 	nr = gup->nr_pages_per_call;
126 	start_time = ktime_get();
127 	for (addr = gup->addr; addr < gup->addr + gup->size; addr = next) {
128 		if (nr != gup->nr_pages_per_call)
129 			break;
130 
131 		next = addr + nr * PAGE_SIZE;
132 		if (next > gup->addr + gup->size) {
133 			next = gup->addr + gup->size;
134 			nr = (next - addr) / PAGE_SIZE;
135 		}
136 
137 		switch (cmd) {
138 		case GUP_FAST_BENCHMARK:
139 			nr = get_user_pages_fast(addr, nr, gup->gup_flags,
140 						 pages + i);
141 			break;
142 		case GUP_BASIC_TEST:
143 			nr = get_user_pages(addr, nr, gup->gup_flags, pages + i);
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 			break;
152 		case PIN_LONGTERM_BENCHMARK:
153 			nr = pin_user_pages(addr, nr,
154 					    gup->gup_flags | FOLL_LONGTERM,
155 					    pages + i);
156 			break;
157 		case DUMP_USER_PAGES_TEST:
158 			if (gup->test_flags & GUP_TEST_FLAG_DUMP_PAGES_USE_PIN)
159 				nr = pin_user_pages(addr, nr, gup->gup_flags,
160 						    pages + i);
161 			else
162 				nr = get_user_pages(addr, nr, gup->gup_flags,
163 						    pages + i);
164 			break;
165 		default:
166 			ret = -EINVAL;
167 			goto unlock;
168 		}
169 
170 		if (nr <= 0)
171 			break;
172 		i += nr;
173 	}
174 	end_time = ktime_get();
175 
176 	/* Shifting the meaning of nr_pages: now it is actual number pinned: */
177 	nr_pages = i;
178 
179 	gup->get_delta_usec = ktime_us_delta(end_time, start_time);
180 	gup->size = addr - gup->addr;
181 
182 	/*
183 	 * Take an un-benchmark-timed moment to verify DMA pinned
184 	 * state: print a warning if any non-dma-pinned pages are found:
185 	 */
186 	verify_dma_pinned(cmd, pages, nr_pages);
187 
188 	if (cmd == DUMP_USER_PAGES_TEST)
189 		dump_pages_test(gup, pages, nr_pages);
190 
191 	start_time = ktime_get();
192 
193 	put_back_pages(cmd, pages, nr_pages, gup->test_flags);
194 
195 	end_time = ktime_get();
196 	gup->put_delta_usec = ktime_us_delta(end_time, start_time);
197 
198 unlock:
199 	if (needs_mmap_lock)
200 		mmap_read_unlock(current->mm);
201 free_pages:
202 	kvfree(pages);
203 	return ret;
204 }
205 
206 static DEFINE_MUTEX(pin_longterm_test_mutex);
207 static struct page **pin_longterm_test_pages;
208 static unsigned long pin_longterm_test_nr_pages;
209 
pin_longterm_test_stop(void)210 static inline void pin_longterm_test_stop(void)
211 {
212 	if (pin_longterm_test_pages) {
213 		if (pin_longterm_test_nr_pages)
214 			unpin_user_pages(pin_longterm_test_pages,
215 					 pin_longterm_test_nr_pages);
216 		kvfree(pin_longterm_test_pages);
217 		pin_longterm_test_pages = NULL;
218 		pin_longterm_test_nr_pages = 0;
219 	}
220 }
221 
pin_longterm_test_start(unsigned long arg)222 static inline int pin_longterm_test_start(unsigned long arg)
223 {
224 	long nr_pages, cur_pages, addr, remaining_pages;
225 	int gup_flags = FOLL_LONGTERM;
226 	struct pin_longterm_test args;
227 	struct page **pages;
228 	int ret = 0;
229 	bool fast;
230 
231 	if (pin_longterm_test_pages)
232 		return -EINVAL;
233 
234 	if (copy_from_user(&args, (void __user *)arg, sizeof(args)))
235 		return -EFAULT;
236 
237 	if (args.flags &
238 	    ~(PIN_LONGTERM_TEST_FLAG_USE_WRITE|PIN_LONGTERM_TEST_FLAG_USE_FAST))
239 		return -EINVAL;
240 	if (!IS_ALIGNED(args.addr | args.size, PAGE_SIZE))
241 		return -EINVAL;
242 	if (args.size > LONG_MAX)
243 		return -EINVAL;
244 	nr_pages = args.size / PAGE_SIZE;
245 	if (!nr_pages)
246 		return -EINVAL;
247 
248 	pages = kvcalloc(nr_pages, sizeof(void *), GFP_KERNEL);
249 	if (!pages)
250 		return -ENOMEM;
251 
252 	if (args.flags & PIN_LONGTERM_TEST_FLAG_USE_WRITE)
253 		gup_flags |= FOLL_WRITE;
254 	fast = !!(args.flags & PIN_LONGTERM_TEST_FLAG_USE_FAST);
255 
256 	if (!fast && mmap_read_lock_killable(current->mm)) {
257 		kvfree(pages);
258 		return -EINTR;
259 	}
260 
261 	pin_longterm_test_pages = pages;
262 	pin_longterm_test_nr_pages = 0;
263 
264 	while (nr_pages - pin_longterm_test_nr_pages) {
265 		remaining_pages = nr_pages - pin_longterm_test_nr_pages;
266 		addr = args.addr + pin_longterm_test_nr_pages * PAGE_SIZE;
267 
268 		if (fast)
269 			cur_pages = pin_user_pages_fast(addr, remaining_pages,
270 							gup_flags, pages);
271 		else
272 			cur_pages = pin_user_pages(addr, remaining_pages,
273 						   gup_flags, pages);
274 		if (cur_pages < 0) {
275 			pin_longterm_test_stop();
276 			ret = cur_pages;
277 			break;
278 		}
279 		pin_longterm_test_nr_pages += cur_pages;
280 		pages += cur_pages;
281 	}
282 
283 	if (!fast)
284 		mmap_read_unlock(current->mm);
285 	return ret;
286 }
287 
pin_longterm_test_read(unsigned long arg)288 static inline int pin_longterm_test_read(unsigned long arg)
289 {
290 	__u64 user_addr;
291 	unsigned long i;
292 
293 	if (!pin_longterm_test_pages)
294 		return -EINVAL;
295 
296 	if (copy_from_user(&user_addr, (void __user *)arg, sizeof(user_addr)))
297 		return -EFAULT;
298 
299 	for (i = 0; i < pin_longterm_test_nr_pages; i++) {
300 		void *addr = kmap_local_page(pin_longterm_test_pages[i]);
301 		unsigned long ret;
302 
303 		ret = copy_to_user((void __user *)(unsigned long)user_addr, addr,
304 				   PAGE_SIZE);
305 		kunmap_local(addr);
306 		if (ret)
307 			return -EFAULT;
308 		user_addr += PAGE_SIZE;
309 	}
310 	return 0;
311 }
312 
pin_longterm_test_ioctl(struct file * filep,unsigned int cmd,unsigned long arg)313 static long pin_longterm_test_ioctl(struct file *filep, unsigned int cmd,
314 				    unsigned long arg)
315 {
316 	int ret = -EINVAL;
317 
318 	if (mutex_lock_killable(&pin_longterm_test_mutex))
319 		return -EINTR;
320 
321 	switch (cmd) {
322 	case PIN_LONGTERM_TEST_START:
323 		ret = pin_longterm_test_start(arg);
324 		break;
325 	case PIN_LONGTERM_TEST_STOP:
326 		pin_longterm_test_stop();
327 		ret = 0;
328 		break;
329 	case PIN_LONGTERM_TEST_READ:
330 		ret = pin_longterm_test_read(arg);
331 		break;
332 	}
333 
334 	mutex_unlock(&pin_longterm_test_mutex);
335 	return ret;
336 }
337 
gup_test_ioctl(struct file * filep,unsigned int cmd,unsigned long arg)338 static long gup_test_ioctl(struct file *filep, unsigned int cmd,
339 		unsigned long arg)
340 {
341 	struct gup_test gup;
342 	int ret;
343 
344 	switch (cmd) {
345 	case GUP_FAST_BENCHMARK:
346 	case PIN_FAST_BENCHMARK:
347 	case PIN_LONGTERM_BENCHMARK:
348 	case GUP_BASIC_TEST:
349 	case PIN_BASIC_TEST:
350 	case DUMP_USER_PAGES_TEST:
351 		break;
352 	case PIN_LONGTERM_TEST_START:
353 	case PIN_LONGTERM_TEST_STOP:
354 	case PIN_LONGTERM_TEST_READ:
355 		return pin_longterm_test_ioctl(filep, cmd, arg);
356 	default:
357 		return -EINVAL;
358 	}
359 
360 	if (copy_from_user(&gup, (void __user *)arg, sizeof(gup)))
361 		return -EFAULT;
362 
363 	ret = __gup_test_ioctl(cmd, &gup);
364 	if (ret)
365 		return ret;
366 
367 	if (copy_to_user((void __user *)arg, &gup, sizeof(gup)))
368 		return -EFAULT;
369 
370 	return 0;
371 }
372 
gup_test_release(struct inode * inode,struct file * file)373 static int gup_test_release(struct inode *inode, struct file *file)
374 {
375 	pin_longterm_test_stop();
376 
377 	return 0;
378 }
379 
380 static const struct file_operations gup_test_fops = {
381 	.open = nonseekable_open,
382 	.unlocked_ioctl = gup_test_ioctl,
383 	.compat_ioctl = compat_ptr_ioctl,
384 	.release = gup_test_release,
385 };
386 
gup_test_init(void)387 static int __init gup_test_init(void)
388 {
389 	debugfs_create_file_unsafe("gup_test", 0600, NULL, NULL,
390 				   &gup_test_fops);
391 
392 	return 0;
393 }
394 
395 late_initcall(gup_test_init);
396