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_longterm(addr, nr, gup->flags & 1,
58 pages + i, NULL);
59 break;
60 case GUP_BENCHMARK:
61 nr = get_user_pages(addr, nr, gup->flags & 1, pages + i,
62 NULL);
63 break;
64 default:
65 return -1;
66 }
67
68 if (nr <= 0)
69 break;
70 i += nr;
71 }
72 end_time = ktime_get();
73
74 gup->get_delta_usec = ktime_us_delta(end_time, start_time);
75 gup->size = addr - gup->addr;
76
77 start_time = ktime_get();
78 for (i = 0; i < nr_pages; i++) {
79 if (!pages[i])
80 break;
81 put_page(pages[i]);
82 }
83 end_time = ktime_get();
84 gup->put_delta_usec = ktime_us_delta(end_time, start_time);
85
86 kvfree(pages);
87 return 0;
88}
89
90static long gup_benchmark_ioctl(struct file *filep, unsigned int cmd,
91 unsigned long arg)
92{
93 struct gup_benchmark gup;
94 int ret;
95
96 switch (cmd) {
97 case GUP_FAST_BENCHMARK:
98 case GUP_LONGTERM_BENCHMARK:
99 case GUP_BENCHMARK:
100 break;
101 default:
102 return -EINVAL;
103 }
104
105 if (copy_from_user(&gup, (void __user *)arg, sizeof(gup)))
106 return -EFAULT;
107
108 ret = __gup_benchmark_ioctl(cmd, &gup);
109 if (ret)
110 return ret;
111
112 if (copy_to_user((void __user *)arg, &gup, sizeof(gup)))
113 return -EFAULT;
114
115 return 0;
116}
117
118static const struct file_operations gup_benchmark_fops = {
119 .open = nonseekable_open,
120 .unlocked_ioctl = gup_benchmark_ioctl,
121};
122
123static int gup_benchmark_init(void)
124{
125 debugfs_create_file_unsafe("gup_benchmark", 0600, NULL, NULL,
126 &gup_benchmark_fops);
127
128 return 0;
129}
130
131late_initcall(gup_benchmark_init);
132