Merge tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi
[linux-2.6-microblaze.git] / mm / gup_test.c
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 "gup_test.h"
8
9 static void put_back_pages(unsigned int cmd, struct page **pages,
10                            unsigned long nr_pages, unsigned int gup_test_flags)
11 {
12         unsigned long i;
13
14         switch (cmd) {
15         case GUP_FAST_BENCHMARK:
16         case GUP_BASIC_TEST:
17                 for (i = 0; i < nr_pages; i++)
18                         put_page(pages[i]);
19                 break;
20
21         case PIN_FAST_BENCHMARK:
22         case PIN_BASIC_TEST:
23         case PIN_LONGTERM_BENCHMARK:
24                 unpin_user_pages(pages, nr_pages);
25                 break;
26         case DUMP_USER_PAGES_TEST:
27                 if (gup_test_flags & GUP_TEST_FLAG_DUMP_PAGES_USE_PIN) {
28                         unpin_user_pages(pages, nr_pages);
29                 } else {
30                         for (i = 0; i < nr_pages; i++)
31                                 put_page(pages[i]);
32
33                 }
34                 break;
35         }
36 }
37
38 static void verify_dma_pinned(unsigned int cmd, struct page **pages,
39                               unsigned long nr_pages)
40 {
41         unsigned long i;
42         struct page *page;
43
44         switch (cmd) {
45         case PIN_FAST_BENCHMARK:
46         case PIN_BASIC_TEST:
47         case PIN_LONGTERM_BENCHMARK:
48                 for (i = 0; i < nr_pages; i++) {
49                         page = pages[i];
50                         if (WARN(!page_maybe_dma_pinned(page),
51                                  "pages[%lu] is NOT dma-pinned\n", i)) {
52
53                                 dump_page(page, "gup_test failure");
54                                 break;
55                         }
56                 }
57                 break;
58         }
59 }
60
61 static void dump_pages_test(struct gup_test *gup, struct page **pages,
62                             unsigned long nr_pages)
63 {
64         unsigned int index_to_dump;
65         unsigned int i;
66
67         /*
68          * Zero out any user-supplied page index that is out of range. Remember:
69          * .which_pages[] contains a 1-based set of page indices.
70          */
71         for (i = 0; i < GUP_TEST_MAX_PAGES_TO_DUMP; i++) {
72                 if (gup->which_pages[i] > nr_pages) {
73                         pr_warn("ZEROING due to out of range: .which_pages[%u]: %u\n",
74                                 i, gup->which_pages[i]);
75                         gup->which_pages[i] = 0;
76                 }
77         }
78
79         for (i = 0; i < GUP_TEST_MAX_PAGES_TO_DUMP; i++) {
80                 index_to_dump = gup->which_pages[i];
81
82                 if (index_to_dump) {
83                         index_to_dump--; // Decode from 1-based, to 0-based
84                         pr_info("---- page #%u, starting from user virt addr: 0x%llx\n",
85                                 index_to_dump, gup->addr);
86                         dump_page(pages[index_to_dump],
87                                   "gup_test: dump_pages() test");
88                 }
89         }
90 }
91
92 static int __gup_test_ioctl(unsigned int cmd,
93                 struct gup_test *gup)
94 {
95         ktime_t start_time, end_time;
96         unsigned long i, nr_pages, addr, next;
97         int nr;
98         struct page **pages;
99         int ret = 0;
100         bool needs_mmap_lock =
101                 cmd != GUP_FAST_BENCHMARK && cmd != PIN_FAST_BENCHMARK;
102
103         if (gup->size > ULONG_MAX)
104                 return -EINVAL;
105
106         nr_pages = gup->size / PAGE_SIZE;
107         pages = kvcalloc(nr_pages, sizeof(void *), GFP_KERNEL);
108         if (!pages)
109                 return -ENOMEM;
110
111         if (needs_mmap_lock && mmap_read_lock_killable(current->mm)) {
112                 ret = -EINTR;
113                 goto free_pages;
114         }
115
116         i = 0;
117         nr = gup->nr_pages_per_call;
118         start_time = ktime_get();
119         for (addr = gup->addr; addr < gup->addr + gup->size; addr = next) {
120                 if (nr != gup->nr_pages_per_call)
121                         break;
122
123                 next = addr + nr * PAGE_SIZE;
124                 if (next > gup->addr + gup->size) {
125                         next = gup->addr + gup->size;
126                         nr = (next - addr) / PAGE_SIZE;
127                 }
128
129                 /* Filter out most gup flags: only allow a tiny subset here: */
130                 gup->flags &= FOLL_WRITE;
131
132                 switch (cmd) {
133                 case GUP_FAST_BENCHMARK:
134                         nr = get_user_pages_fast(addr, nr, gup->flags,
135                                                  pages + i);
136                         break;
137                 case GUP_BASIC_TEST:
138                         nr = get_user_pages(addr, nr, gup->flags, pages + i,
139                                             NULL);
140                         break;
141                 case PIN_FAST_BENCHMARK:
142                         nr = pin_user_pages_fast(addr, nr, gup->flags,
143                                                  pages + i);
144                         break;
145                 case PIN_BASIC_TEST:
146                         nr = pin_user_pages(addr, nr, gup->flags, pages + i,
147                                             NULL);
148                         break;
149                 case PIN_LONGTERM_BENCHMARK:
150                         nr = pin_user_pages(addr, nr,
151                                             gup->flags | FOLL_LONGTERM,
152                                             pages + i, NULL);
153                         break;
154                 case DUMP_USER_PAGES_TEST:
155                         if (gup->flags & GUP_TEST_FLAG_DUMP_PAGES_USE_PIN)
156                                 nr = pin_user_pages(addr, nr, gup->flags,
157                                                     pages + i, NULL);
158                         else
159                                 nr = get_user_pages(addr, nr, gup->flags,
160                                                     pages + i, NULL);
161                         break;
162                 default:
163                         ret = -EINVAL;
164                         goto unlock;
165                 }
166
167                 if (nr <= 0)
168                         break;
169                 i += nr;
170         }
171         end_time = ktime_get();
172
173         /* Shifting the meaning of nr_pages: now it is actual number pinned: */
174         nr_pages = i;
175
176         gup->get_delta_usec = ktime_us_delta(end_time, start_time);
177         gup->size = addr - gup->addr;
178
179         /*
180          * Take an un-benchmark-timed moment to verify DMA pinned
181          * state: print a warning if any non-dma-pinned pages are found:
182          */
183         verify_dma_pinned(cmd, pages, nr_pages);
184
185         if (cmd == DUMP_USER_PAGES_TEST)
186                 dump_pages_test(gup, pages, nr_pages);
187
188         start_time = ktime_get();
189
190         put_back_pages(cmd, pages, nr_pages, gup->flags);
191
192         end_time = ktime_get();
193         gup->put_delta_usec = ktime_us_delta(end_time, start_time);
194
195 unlock:
196         if (needs_mmap_lock)
197                 mmap_read_unlock(current->mm);
198 free_pages:
199         kvfree(pages);
200         return ret;
201 }
202
203 static long gup_test_ioctl(struct file *filep, unsigned int cmd,
204                 unsigned long arg)
205 {
206         struct gup_test gup;
207         int ret;
208
209         switch (cmd) {
210         case GUP_FAST_BENCHMARK:
211         case PIN_FAST_BENCHMARK:
212         case PIN_LONGTERM_BENCHMARK:
213         case GUP_BASIC_TEST:
214         case PIN_BASIC_TEST:
215         case DUMP_USER_PAGES_TEST:
216                 break;
217         default:
218                 return -EINVAL;
219         }
220
221         if (copy_from_user(&gup, (void __user *)arg, sizeof(gup)))
222                 return -EFAULT;
223
224         ret = __gup_test_ioctl(cmd, &gup);
225         if (ret)
226                 return ret;
227
228         if (copy_to_user((void __user *)arg, &gup, sizeof(gup)))
229                 return -EFAULT;
230
231         return 0;
232 }
233
234 static const struct file_operations gup_test_fops = {
235         .open = nonseekable_open,
236         .unlocked_ioctl = gup_test_ioctl,
237 };
238
239 static int __init gup_test_init(void)
240 {
241         debugfs_create_file_unsafe("gup_test", 0600, NULL, NULL,
242                                    &gup_test_fops);
243
244         return 0;
245 }
246
247 late_initcall(gup_test_init);