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 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
dump_pages_test(struct gup_test * gup,struct page ** pages,unsigned long nr_pages)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
__gup_test_ioctl(unsigned int cmd,struct gup_test * gup)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
pin_longterm_test_stop(void)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
pin_longterm_test_start(unsigned long arg)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
pin_longterm_test_read(unsigned long arg)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
pin_longterm_test_ioctl(struct file * filep,unsigned int cmd,unsigned long arg)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
gup_test_ioctl(struct file * filep,unsigned int cmd,unsigned long arg)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
gup_test_release(struct inode * inode,struct file * file)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 .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