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
12 struct 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
__gup_benchmark_ioctl(unsigned int cmd,struct gup_benchmark * gup)22 static 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 int ret = 0;
30
31 if (gup->size > ULONG_MAX)
32 return -EINVAL;
33
34 nr_pages = gup->size / PAGE_SIZE;
35 pages = kvcalloc(nr_pages, sizeof(void *), GFP_KERNEL);
36 if (!pages)
37 return -ENOMEM;
38
39 i = 0;
40 nr = gup->nr_pages_per_call;
41 start_time = ktime_get();
42 for (addr = gup->addr; addr < gup->addr + gup->size; addr = next) {
43 if (nr != gup->nr_pages_per_call)
44 break;
45
46 next = addr + nr * PAGE_SIZE;
47 if (next > gup->addr + gup->size) {
48 next = gup->addr + gup->size;
49 nr = (next - addr) / PAGE_SIZE;
50 }
51
52 switch (cmd) {
53 case GUP_FAST_BENCHMARK:
54 nr = get_user_pages_fast(addr, nr, gup->flags & 1,
55 pages + i);
56 break;
57 case GUP_LONGTERM_BENCHMARK:
58 nr = get_user_pages(addr, nr,
59 (gup->flags & 1) | FOLL_LONGTERM,
60 pages + i, NULL);
61 break;
62 case GUP_BENCHMARK:
63 nr = get_user_pages(addr, nr, gup->flags & 1, pages + i,
64 NULL);
65 break;
66 default:
67 kvfree(pages);
68 ret = -EINVAL;
69 goto out;
70 }
71
72 if (nr <= 0)
73 break;
74 i += nr;
75 }
76 end_time = ktime_get();
77
78 gup->get_delta_usec = ktime_us_delta(end_time, start_time);
79 gup->size = addr - gup->addr;
80
81 start_time = ktime_get();
82 for (i = 0; i < nr_pages; i++) {
83 if (!pages[i])
84 break;
85 put_page(pages[i]);
86 }
87 end_time = ktime_get();
88 gup->put_delta_usec = ktime_us_delta(end_time, start_time);
89
90 kvfree(pages);
91 out:
92 return ret;
93 }
94
gup_benchmark_ioctl(struct file * filep,unsigned int cmd,unsigned long arg)95 static long gup_benchmark_ioctl(struct file *filep, unsigned int cmd,
96 unsigned long arg)
97 {
98 struct gup_benchmark gup;
99 int ret;
100
101 switch (cmd) {
102 case GUP_FAST_BENCHMARK:
103 case GUP_LONGTERM_BENCHMARK:
104 case GUP_BENCHMARK:
105 break;
106 default:
107 return -EINVAL;
108 }
109
110 if (copy_from_user(&gup, (void __user *)arg, sizeof(gup)))
111 return -EFAULT;
112
113 ret = __gup_benchmark_ioctl(cmd, &gup);
114 if (ret)
115 return ret;
116
117 if (copy_to_user((void __user *)arg, &gup, sizeof(gup)))
118 return -EFAULT;
119
120 return 0;
121 }
122
123 static const struct file_operations gup_benchmark_fops = {
124 .open = nonseekable_open,
125 .unlocked_ioctl = gup_benchmark_ioctl,
126 };
127
gup_benchmark_init(void)128 static int gup_benchmark_init(void)
129 {
130 debugfs_create_file_unsafe("gup_benchmark", 0600, NULL, NULL,
131 &gup_benchmark_fops);
132
133 return 0;
134 }
135
136 late_initcall(gup_benchmark_init);
137