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review.evervolv.com / android_kernel_oneplus_sm8150 / 997dbb4967da248808850c250182ef2528fff2d1 / . / arch / s390 / oprofile / hwsampler_files.c
blob: 493f7cc4e861acf244b921145974c312c6d33b46 [file] [log] [blame]
Heinz Graalfs997dbb42011-01-21 10:06:53 +0000[diff] [blame^]1/**
2 * arch/s390/oprofile/hwsampler_files.c
3 *
4 * Copyright IBM Corp. 2010
5 * Author: Mahesh Salgaonkar (mahesh@linux.vnet.ibm.com)
6 */
7#include <linux/oprofile.h>
8#include <linux/errno.h>
9#include <linux/fs.h>
10
11#include "hwsampler.h"
12
13#define DEFAULT_INTERVAL 4096
14
15#define DEFAULT_SDBT_BLOCKS 1
16#define DEFAULT_SDB_BLOCKS 511
17
18static unsigned long oprofile_hw_interval = DEFAULT_INTERVAL;
19static unsigned long oprofile_min_interval;
20static unsigned long oprofile_max_interval;
21
22static unsigned long oprofile_sdbt_blocks = DEFAULT_SDBT_BLOCKS;
23static unsigned long oprofile_sdb_blocks = DEFAULT_SDB_BLOCKS;
24
25static unsigned long oprofile_hwsampler;
26
27static int oprofile_hwsampler_start(void)
28{
29 int retval;
30
31 retval = hwsampler_allocate(oprofile_sdbt_blocks, oprofile_sdb_blocks);
32 if (retval)
33 return retval;
34
35 retval = hwsampler_start_all(oprofile_hw_interval);
36 if (retval)
37 hwsampler_deallocate();
38
39 return retval;
40}
41
42static void oprofile_hwsampler_stop(void)
43{
44 hwsampler_stop_all();
45 hwsampler_deallocate();
46 return;
47}
48
49int oprofile_arch_set_hwsampler(struct oprofile_operations *ops)
50{
51 printk(KERN_INFO "oprofile: using hardware sampling\n");
52 ops->start = oprofile_hwsampler_start;
53 ops->stop = oprofile_hwsampler_stop;
54 ops->cpu_type = "timer";
55
56 return 0;
57}
58
59static ssize_t hwsampler_read(struct file *file, char __user *buf,
60 size_t count, loff_t *offset)
61{
62 return oprofilefs_ulong_to_user(oprofile_hwsampler, buf, count, offset);
63}
64
65static ssize_t hwsampler_write(struct file *file, char const __user *buf,
66 size_t count, loff_t *offset)
67{
68 unsigned long val;
69 int retval;
70
71 if (*offset)
72 return -EINVAL;
73
74 retval = oprofilefs_ulong_from_user(&val, buf, count);
75 if (retval)
76 return retval;
77
78 if (oprofile_hwsampler == val)
79 return -EINVAL;
80
81 retval = oprofile_set_hwsampler(val);
82
83 if (retval)
84 return retval;
85
86 oprofile_hwsampler = val;
87 return count;
88}
89
90static const struct file_operations hwsampler_fops = {
91 .read = hwsampler_read,
92 .write = hwsampler_write,
93};
94
95static int oprofile_create_hwsampling_files(struct super_block *sb,
96 struct dentry *root)
97{
98 struct dentry *hw_dir;
99
100 /* reinitialize default values */
101 oprofile_hwsampler = 1;
102
103 hw_dir = oprofilefs_mkdir(sb, root, "hwsampling");
104 if (!hw_dir)
105 return -EINVAL;
106
107 oprofilefs_create_file(sb, hw_dir, "hwsampler", &hwsampler_fops);
108 oprofilefs_create_ulong(sb, hw_dir, "hw_interval",
109 &oprofile_hw_interval);
110 oprofilefs_create_ro_ulong(sb, hw_dir, "hw_min_interval",
111 &oprofile_min_interval);
112 oprofilefs_create_ro_ulong(sb, hw_dir, "hw_max_interval",
113 &oprofile_max_interval);
114 oprofilefs_create_ulong(sb, hw_dir, "hw_sdbt_blocks",
115 &oprofile_sdbt_blocks);
116
117 return 0;
118}
119
120int oprofile_hwsampler_init(struct oprofile_operations* ops)
121{
122 if (hwsampler_setup())
123 return -ENODEV;
124
125 /*
126 * create hwsampler files only if hwsampler_setup() succeeds.
127 */
128 ops->create_files = oprofile_create_hwsampling_files;
129 oprofile_min_interval = hwsampler_query_min_interval();
130 if (oprofile_min_interval < 0) {
131 oprofile_min_interval = 0;
132 return -ENODEV;
133 }
134 oprofile_max_interval = hwsampler_query_max_interval();
135 if (oprofile_max_interval < 0) {
136 oprofile_max_interval = 0;
137 return -ENODEV;
138 }
139 oprofile_arch_set_hwsampler(ops);
140 return 0;
141}
142
143void oprofile_hwsampler_exit(void)
144{
145 hwsampler_shutdown();
146}