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64c349f4 KS |
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) | |
714a3a1e KB |
9 | #define GUP_LONGTERM_BENCHMARK _IOWR('g', 2, struct gup_benchmark) |
10 | #define GUP_BENCHMARK _IOWR('g', 3, struct gup_benchmark) | |
64c349f4 KS |
11 | |
12 | struct gup_benchmark { | |
26db3d09 KB |
13 | __u64 get_delta_usec; |
14 | __u64 put_delta_usec; | |
64c349f4 KS |
15 | __u64 addr; |
16 | __u64 size; | |
17 | __u32 nr_pages_per_call; | |
18 | __u32 flags; | |
26db3d09 | 19 | __u64 expansion[10]; /* For future use */ |
64c349f4 KS |
20 | }; |
21 | ||
22 | static int __gup_benchmark_ioctl(unsigned int cmd, | |
23 | struct gup_benchmark *gup) | |
24 | { | |
25 | ktime_t start_time, end_time; | |
51896864 Y |
26 | unsigned long i, nr_pages, addr, next; |
27 | int nr; | |
64c349f4 | 28 | struct page **pages; |
a7c46c0c | 29 | int ret = 0; |
64c349f4 | 30 | |
4b408c74 DC |
31 | if (gup->size > ULONG_MAX) |
32 | return -EINVAL; | |
33 | ||
64c349f4 | 34 | nr_pages = gup->size / PAGE_SIZE; |
778e1cdd | 35 | pages = kvcalloc(nr_pages, sizeof(void *), GFP_KERNEL); |
64c349f4 KS |
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 | ||
bdffe23e JH |
52 | /* Filter out most gup flags: only allow a tiny subset here: */ |
53 | gup->flags &= FOLL_WRITE; | |
54 | ||
714a3a1e KB |
55 | switch (cmd) { |
56 | case GUP_FAST_BENCHMARK: | |
bdffe23e | 57 | nr = get_user_pages_fast(addr, nr, gup->flags, |
714a3a1e KB |
58 | pages + i); |
59 | break; | |
60 | case GUP_LONGTERM_BENCHMARK: | |
932f4a63 | 61 | nr = get_user_pages(addr, nr, |
bdffe23e | 62 | gup->flags | FOLL_LONGTERM, |
932f4a63 | 63 | pages + i, NULL); |
714a3a1e KB |
64 | break; |
65 | case GUP_BENCHMARK: | |
bdffe23e | 66 | nr = get_user_pages(addr, nr, gup->flags, pages + i, |
714a3a1e KB |
67 | NULL); |
68 | break; | |
69 | default: | |
a7c46c0c NE |
70 | kvfree(pages); |
71 | ret = -EINVAL; | |
72 | goto out; | |
714a3a1e KB |
73 | } |
74 | ||
09e35a4a MT |
75 | if (nr <= 0) |
76 | break; | |
64c349f4 KS |
77 | i += nr; |
78 | } | |
79 | end_time = ktime_get(); | |
80 | ||
26db3d09 | 81 | gup->get_delta_usec = ktime_us_delta(end_time, start_time); |
64c349f4 KS |
82 | gup->size = addr - gup->addr; |
83 | ||
26db3d09 | 84 | start_time = ktime_get(); |
64c349f4 KS |
85 | for (i = 0; i < nr_pages; i++) { |
86 | if (!pages[i]) | |
87 | break; | |
88 | put_page(pages[i]); | |
89 | } | |
26db3d09 KB |
90 | end_time = ktime_get(); |
91 | gup->put_delta_usec = ktime_us_delta(end_time, start_time); | |
64c349f4 KS |
92 | |
93 | kvfree(pages); | |
a7c46c0c NE |
94 | out: |
95 | return ret; | |
64c349f4 KS |
96 | } |
97 | ||
98 | static long gup_benchmark_ioctl(struct file *filep, unsigned int cmd, | |
99 | unsigned long arg) | |
100 | { | |
101 | struct gup_benchmark gup; | |
102 | int ret; | |
103 | ||
714a3a1e KB |
104 | switch (cmd) { |
105 | case GUP_FAST_BENCHMARK: | |
106 | case GUP_LONGTERM_BENCHMARK: | |
107 | case GUP_BENCHMARK: | |
108 | break; | |
109 | default: | |
64c349f4 | 110 | return -EINVAL; |
714a3a1e | 111 | } |
64c349f4 KS |
112 | |
113 | if (copy_from_user(&gup, (void __user *)arg, sizeof(gup))) | |
114 | return -EFAULT; | |
115 | ||
116 | ret = __gup_benchmark_ioctl(cmd, &gup); | |
117 | if (ret) | |
118 | return ret; | |
119 | ||
120 | if (copy_to_user((void __user *)arg, &gup, sizeof(gup))) | |
121 | return -EFAULT; | |
122 | ||
123 | return 0; | |
124 | } | |
125 | ||
126 | static const struct file_operations gup_benchmark_fops = { | |
127 | .open = nonseekable_open, | |
128 | .unlocked_ioctl = gup_benchmark_ioctl, | |
129 | }; | |
130 | ||
131 | static int gup_benchmark_init(void) | |
132 | { | |
d9f7979c GKH |
133 | debugfs_create_file_unsafe("gup_benchmark", 0600, NULL, NULL, |
134 | &gup_benchmark_fops); | |
64c349f4 KS |
135 | |
136 | return 0; | |
137 | } | |
138 | ||
139 | late_initcall(gup_benchmark_init); |