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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
8#define GUP_FAST_BENCHMARK _IOWR('g', 1, struct gup_benchmark)
9#define GUP_LONGTERM_BENCHMARK _IOWR('g', 2, struct gup_benchmark)
10#define GUP_BENCHMARK _IOWR('g', 3, struct gup_benchmark)
11
12struct gup_benchmark {
13 __u64 get_delta_usec;
14 __u64 put_delta_usec;
15 __u64 addr;
16 __u64 size;
17 __u32 nr_pages_per_call;
18 __u32 flags;
19 __u64 expansion[10]; /* For future use */
20};
21
22static int __gup_benchmark_ioctl(unsigned int cmd,
23 struct gup_benchmark *gup)
24{
25 ktime_t start_time, end_time;
26 unsigned long i, nr_pages, addr, next;
27 int nr;
28 struct page **pages;
29
30 if (gup->size > ULONG_MAX)
31 return -EINVAL;
32
33 nr_pages = gup->size / PAGE_SIZE;
34 pages = kvcalloc(nr_pages, sizeof(void *), GFP_KERNEL);
35 if (!pages)
36 return -ENOMEM;
37
38 i = 0;
39 nr = gup->nr_pages_per_call;
40 start_time = ktime_get();
41 for (addr = gup->addr; addr < gup->addr + gup->size; addr = next) {
42 if (nr != gup->nr_pages_per_call)
43 break;
44
45 next = addr + nr * PAGE_SIZE;
46 if (next > gup->addr + gup->size) {
47 next = gup->addr + gup->size;
48 nr = (next - addr) / PAGE_SIZE;
49 }
50
51 switch (cmd) {
52 case GUP_FAST_BENCHMARK:
53 nr = get_user_pages_fast(addr, nr, gup->flags & 1,
54 pages + i);
55 break;
56 case GUP_LONGTERM_BENCHMARK:
57 nr = get_user_pages(addr, nr,
58 (gup->flags & 1) | FOLL_LONGTERM,
59 pages + i, NULL);
60 break;
61 case GUP_BENCHMARK:
62 nr = get_user_pages(addr, nr, gup->flags & 1, pages + i,
63 NULL);
64 break;
65 default:
66 return -1;
67 }
68
69 if (nr <= 0)
70 break;
71 i += nr;
72 }
73 end_time = ktime_get();
74
75 gup->get_delta_usec = ktime_us_delta(end_time, start_time);
76 gup->size = addr - gup->addr;
77
78 start_time = ktime_get();
79 for (i = 0; i < nr_pages; i++) {
80 if (!pages[i])
81 break;
82 put_page(pages[i]);
83 }
84 end_time = ktime_get();
85 gup->put_delta_usec = ktime_us_delta(end_time, start_time);
86
87 kvfree(pages);
88 return 0;
89}
90
91static long gup_benchmark_ioctl(struct file *filep, unsigned int cmd,
92 unsigned long arg)
93{
94 struct gup_benchmark gup;
95 int ret;
96
97 switch (cmd) {
98 case GUP_FAST_BENCHMARK:
99 case GUP_LONGTERM_BENCHMARK:
100 case GUP_BENCHMARK:
101 break;
102 default:
103 return -EINVAL;
104 }
105
106 if (copy_from_user(&gup, (void __user *)arg, sizeof(gup)))
107 return -EFAULT;
108
109 ret = __gup_benchmark_ioctl(cmd, &gup);
110 if (ret)
111 return ret;
112
113 if (copy_to_user((void __user *)arg, &gup, sizeof(gup)))
114 return -EFAULT;
115
116 return 0;
117}
118
119static const struct file_operations gup_benchmark_fops = {
120 .open = nonseekable_open,
121 .unlocked_ioctl = gup_benchmark_ioctl,
122};
123
124static int gup_benchmark_init(void)
125{
126 debugfs_create_file_unsafe("gup_benchmark", 0600, NULL, NULL,
127 &gup_benchmark_fops);
128
129 return 0;
130}
131
132late_initcall(gup_benchmark_init);
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
8#define GUP_FAST_BENCHMARK _IOWR('g', 1, struct gup_benchmark)
9#define GUP_LONGTERM_BENCHMARK _IOWR('g', 2, struct gup_benchmark)
10#define GUP_BENCHMARK _IOWR('g', 3, struct gup_benchmark)
11#define PIN_FAST_BENCHMARK _IOWR('g', 4, struct gup_benchmark)
12#define PIN_BENCHMARK _IOWR('g', 5, struct gup_benchmark)
13
14struct gup_benchmark {
15 __u64 get_delta_usec;
16 __u64 put_delta_usec;
17 __u64 addr;
18 __u64 size;
19 __u32 nr_pages_per_call;
20 __u32 flags;
21 __u64 expansion[10]; /* For future use */
22};
23
24static void put_back_pages(unsigned int cmd, struct page **pages,
25 unsigned long nr_pages)
26{
27 unsigned long i;
28
29 switch (cmd) {
30 case GUP_FAST_BENCHMARK:
31 case GUP_LONGTERM_BENCHMARK:
32 case GUP_BENCHMARK:
33 for (i = 0; i < nr_pages; i++)
34 put_page(pages[i]);
35 break;
36
37 case PIN_FAST_BENCHMARK:
38 case PIN_BENCHMARK:
39 unpin_user_pages(pages, nr_pages);
40 break;
41 }
42}
43
44static void verify_dma_pinned(unsigned int cmd, struct page **pages,
45 unsigned long nr_pages)
46{
47 unsigned long i;
48 struct page *page;
49
50 switch (cmd) {
51 case PIN_FAST_BENCHMARK:
52 case PIN_BENCHMARK:
53 for (i = 0; i < nr_pages; i++) {
54 page = pages[i];
55 if (WARN(!page_maybe_dma_pinned(page),
56 "pages[%lu] is NOT dma-pinned\n", i)) {
57
58 dump_page(page, "gup_benchmark failure");
59 break;
60 }
61 }
62 break;
63 }
64}
65
66static int __gup_benchmark_ioctl(unsigned int cmd,
67 struct gup_benchmark *gup)
68{
69 ktime_t start_time, end_time;
70 unsigned long i, nr_pages, addr, next;
71 int nr;
72 struct page **pages;
73 int ret = 0;
74
75 if (gup->size > ULONG_MAX)
76 return -EINVAL;
77
78 nr_pages = gup->size / PAGE_SIZE;
79 pages = kvcalloc(nr_pages, sizeof(void *), GFP_KERNEL);
80 if (!pages)
81 return -ENOMEM;
82
83 i = 0;
84 nr = gup->nr_pages_per_call;
85 start_time = ktime_get();
86 for (addr = gup->addr; addr < gup->addr + gup->size; addr = next) {
87 if (nr != gup->nr_pages_per_call)
88 break;
89
90 next = addr + nr * PAGE_SIZE;
91 if (next > gup->addr + gup->size) {
92 next = gup->addr + gup->size;
93 nr = (next - addr) / PAGE_SIZE;
94 }
95
96 /* Filter out most gup flags: only allow a tiny subset here: */
97 gup->flags &= FOLL_WRITE;
98
99 switch (cmd) {
100 case GUP_FAST_BENCHMARK:
101 nr = get_user_pages_fast(addr, nr, gup->flags,
102 pages + i);
103 break;
104 case GUP_LONGTERM_BENCHMARK:
105 nr = get_user_pages(addr, nr,
106 gup->flags | FOLL_LONGTERM,
107 pages + i, NULL);
108 break;
109 case GUP_BENCHMARK:
110 nr = get_user_pages(addr, nr, gup->flags, pages + i,
111 NULL);
112 break;
113 case PIN_FAST_BENCHMARK:
114 nr = pin_user_pages_fast(addr, nr, gup->flags,
115 pages + i);
116 break;
117 case PIN_BENCHMARK:
118 nr = pin_user_pages(addr, nr, gup->flags, pages + i,
119 NULL);
120 break;
121 default:
122 kvfree(pages);
123 ret = -EINVAL;
124 goto out;
125 }
126
127 if (nr <= 0)
128 break;
129 i += nr;
130 }
131 end_time = ktime_get();
132
133 /* Shifting the meaning of nr_pages: now it is actual number pinned: */
134 nr_pages = i;
135
136 gup->get_delta_usec = ktime_us_delta(end_time, start_time);
137 gup->size = addr - gup->addr;
138
139 /*
140 * Take an un-benchmark-timed moment to verify DMA pinned
141 * state: print a warning if any non-dma-pinned pages are found:
142 */
143 verify_dma_pinned(cmd, pages, nr_pages);
144
145 start_time = ktime_get();
146
147 put_back_pages(cmd, pages, nr_pages);
148
149 end_time = ktime_get();
150 gup->put_delta_usec = ktime_us_delta(end_time, start_time);
151
152 kvfree(pages);
153out:
154 return ret;
155}
156
157static long gup_benchmark_ioctl(struct file *filep, unsigned int cmd,
158 unsigned long arg)
159{
160 struct gup_benchmark gup;
161 int ret;
162
163 switch (cmd) {
164 case GUP_FAST_BENCHMARK:
165 case GUP_LONGTERM_BENCHMARK:
166 case GUP_BENCHMARK:
167 case PIN_FAST_BENCHMARK:
168 case PIN_BENCHMARK:
169 break;
170 default:
171 return -EINVAL;
172 }
173
174 if (copy_from_user(&gup, (void __user *)arg, sizeof(gup)))
175 return -EFAULT;
176
177 ret = __gup_benchmark_ioctl(cmd, &gup);
178 if (ret)
179 return ret;
180
181 if (copy_to_user((void __user *)arg, &gup, sizeof(gup)))
182 return -EFAULT;
183
184 return 0;
185}
186
187static const struct file_operations gup_benchmark_fops = {
188 .open = nonseekable_open,
189 .unlocked_ioctl = gup_benchmark_ioctl,
190};
191
192static int gup_benchmark_init(void)
193{
194 debugfs_create_file_unsafe("gup_benchmark", 0600, NULL, NULL,
195 &gup_benchmark_fops);
196
197 return 0;
198}
199
200late_initcall(gup_benchmark_init);