1 /**
2 * arch/s390/oprofile/init.c
3 *
4 * S390 Version
5 * Copyright (C) 2003 IBM Deutschland Entwicklung GmbH, IBM Corporation
6 * Author(s): Thomas Spatzier (tspat@de.ibm.com)
7 * Author(s): Mahesh Salgaonkar (mahesh@linux.vnet.ibm.com)
8 * Author(s): Heinz Graalfs (graalfs@linux.vnet.ibm.com)
9 *
10 * @remark Copyright 2002-2011 OProfile authors
11 */
12
13 #include <linux/oprofile.h>
14 #include <linux/init.h>
15 #include <linux/errno.h>
16 #include <linux/oprofile.h>
17 #include <linux/errno.h>
18 #include <linux/fs.h>
19
20 #include "../../../drivers/oprofile/oprof.h"
21
22 extern void s390_backtrace(struct pt_regs * const regs, unsigned int depth);
23
24 #ifdef CONFIG_64BIT
25
26 #include "hwsampler.h"
27
28 #define DEFAULT_INTERVAL 4096
29
30 #define DEFAULT_SDBT_BLOCKS 1
31 #define DEFAULT_SDB_BLOCKS 511
32
33 static unsigned long oprofile_hw_interval = DEFAULT_INTERVAL;
34 static unsigned long oprofile_min_interval;
35 static unsigned long oprofile_max_interval;
36
37 static unsigned long oprofile_sdbt_blocks = DEFAULT_SDBT_BLOCKS;
38 static unsigned long oprofile_sdb_blocks = DEFAULT_SDB_BLOCKS;
39
40 static int hwsampler_file;
41 static int hwsampler_running; /* start_mutex must be held to change */
42
43 static struct oprofile_operations timer_ops;
44
oprofile_hwsampler_start(void)45 static int oprofile_hwsampler_start(void)
46 {
47 int retval;
48
49 hwsampler_running = hwsampler_file;
50
51 if (!hwsampler_running)
52 return timer_ops.start();
53
54 retval = hwsampler_allocate(oprofile_sdbt_blocks, oprofile_sdb_blocks);
55 if (retval)
56 return retval;
57
58 retval = hwsampler_start_all(oprofile_hw_interval);
59 if (retval)
60 hwsampler_deallocate();
61
62 return retval;
63 }
64
oprofile_hwsampler_stop(void)65 static void oprofile_hwsampler_stop(void)
66 {
67 if (!hwsampler_running) {
68 timer_ops.stop();
69 return;
70 }
71
72 hwsampler_stop_all();
73 hwsampler_deallocate();
74 return;
75 }
76
hwsampler_read(struct file * file,char __user * buf,size_t count,loff_t * offset)77 static ssize_t hwsampler_read(struct file *file, char __user *buf,
78 size_t count, loff_t *offset)
79 {
80 return oprofilefs_ulong_to_user(hwsampler_file, buf, count, offset);
81 }
82
hwsampler_write(struct file * file,char const __user * buf,size_t count,loff_t * offset)83 static ssize_t hwsampler_write(struct file *file, char const __user *buf,
84 size_t count, loff_t *offset)
85 {
86 unsigned long val;
87 int retval;
88
89 if (*offset)
90 return -EINVAL;
91
92 retval = oprofilefs_ulong_from_user(&val, buf, count);
93 if (retval)
94 return retval;
95
96 if (oprofile_started)
97 /*
98 * save to do without locking as we set
99 * hwsampler_running in start() when start_mutex is
100 * held
101 */
102 return -EBUSY;
103
104 hwsampler_file = val;
105
106 return count;
107 }
108
109 static const struct file_operations hwsampler_fops = {
110 .read = hwsampler_read,
111 .write = hwsampler_write,
112 };
113
oprofile_create_hwsampling_files(struct super_block * sb,struct dentry * root)114 static int oprofile_create_hwsampling_files(struct super_block *sb,
115 struct dentry *root)
116 {
117 struct dentry *hw_dir;
118
119 /* reinitialize default values */
120 hwsampler_file = 1;
121
122 hw_dir = oprofilefs_mkdir(sb, root, "hwsampling");
123 if (!hw_dir)
124 return -EINVAL;
125
126 oprofilefs_create_file(sb, hw_dir, "hwsampler", &hwsampler_fops);
127 oprofilefs_create_ulong(sb, hw_dir, "hw_interval",
128 &oprofile_hw_interval);
129 oprofilefs_create_ro_ulong(sb, hw_dir, "hw_min_interval",
130 &oprofile_min_interval);
131 oprofilefs_create_ro_ulong(sb, hw_dir, "hw_max_interval",
132 &oprofile_max_interval);
133 oprofilefs_create_ulong(sb, hw_dir, "hw_sdbt_blocks",
134 &oprofile_sdbt_blocks);
135
136 return 0;
137 }
138
oprofile_hwsampler_init(struct oprofile_operations * ops)139 static int oprofile_hwsampler_init(struct oprofile_operations *ops)
140 {
141 if (hwsampler_setup())
142 return -ENODEV;
143
144 /*
145 * create hwsampler files only if hwsampler_setup() succeeds.
146 */
147 oprofile_min_interval = hwsampler_query_min_interval();
148 if (oprofile_min_interval == 0)
149 return -ENODEV;
150 oprofile_max_interval = hwsampler_query_max_interval();
151 if (oprofile_max_interval == 0)
152 return -ENODEV;
153
154 if (oprofile_timer_init(ops))
155 return -ENODEV;
156
157 printk(KERN_INFO "oprofile: using hardware sampling\n");
158
159 memcpy(&timer_ops, ops, sizeof(timer_ops));
160
161 ops->start = oprofile_hwsampler_start;
162 ops->stop = oprofile_hwsampler_stop;
163 ops->create_files = oprofile_create_hwsampling_files;
164
165 return 0;
166 }
167
oprofile_hwsampler_exit(void)168 static void oprofile_hwsampler_exit(void)
169 {
170 oprofile_timer_exit();
171 hwsampler_shutdown();
172 }
173
174 #endif /* CONFIG_64BIT */
175
oprofile_arch_init(struct oprofile_operations * ops)176 int __init oprofile_arch_init(struct oprofile_operations *ops)
177 {
178 ops->backtrace = s390_backtrace;
179
180 #ifdef CONFIG_64BIT
181 return oprofile_hwsampler_init(ops);
182 #else
183 return -ENODEV;
184 #endif
185 }
186
oprofile_arch_exit(void)187 void oprofile_arch_exit(void)
188 {
189 #ifdef CONFIG_64BIT
190 oprofile_hwsampler_exit();
191 #endif
192 }
193