Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc
[linux-2.6.git] / arch / s390 / oprofile / init.c
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/fs.h>
17
18 #include "../../../drivers/oprofile/oprof.h"
19
20 extern void s390_backtrace(struct pt_regs * const regs, unsigned int depth);
21
22 #ifdef CONFIG_64BIT
23
24 #include "hwsampler.h"
25
26 #define DEFAULT_INTERVAL        4127518
27
28 #define DEFAULT_SDBT_BLOCKS     1
29 #define DEFAULT_SDB_BLOCKS      511
30
31 static unsigned long oprofile_hw_interval = DEFAULT_INTERVAL;
32 static unsigned long oprofile_min_interval;
33 static unsigned long oprofile_max_interval;
34
35 static unsigned long oprofile_sdbt_blocks = DEFAULT_SDBT_BLOCKS;
36 static unsigned long oprofile_sdb_blocks = DEFAULT_SDB_BLOCKS;
37
38 static int hwsampler_file;
39 static int hwsampler_running;   /* start_mutex must be held to change */
40
41 static struct oprofile_operations timer_ops;
42
43 static int oprofile_hwsampler_start(void)
44 {
45         int retval;
46
47         hwsampler_running = hwsampler_file;
48
49         if (!hwsampler_running)
50                 return timer_ops.start();
51
52         retval = hwsampler_allocate(oprofile_sdbt_blocks, oprofile_sdb_blocks);
53         if (retval)
54                 return retval;
55
56         retval = hwsampler_start_all(oprofile_hw_interval);
57         if (retval)
58                 hwsampler_deallocate();
59
60         return retval;
61 }
62
63 static void oprofile_hwsampler_stop(void)
64 {
65         if (!hwsampler_running) {
66                 timer_ops.stop();
67                 return;
68         }
69
70         hwsampler_stop_all();
71         hwsampler_deallocate();
72         return;
73 }
74
75 static ssize_t hwsampler_read(struct file *file, char __user *buf,
76                 size_t count, loff_t *offset)
77 {
78         return oprofilefs_ulong_to_user(hwsampler_file, buf, count, offset);
79 }
80
81 static ssize_t hwsampler_write(struct file *file, char const __user *buf,
82                 size_t count, loff_t *offset)
83 {
84         unsigned long val;
85         int retval;
86
87         if (*offset)
88                 return -EINVAL;
89
90         retval = oprofilefs_ulong_from_user(&val, buf, count);
91         if (retval <= 0)
92                 return retval;
93
94         if (oprofile_started)
95                 /*
96                  * save to do without locking as we set
97                  * hwsampler_running in start() when start_mutex is
98                  * held
99                  */
100                 return -EBUSY;
101
102         hwsampler_file = val;
103
104         return count;
105 }
106
107 static const struct file_operations hwsampler_fops = {
108         .read           = hwsampler_read,
109         .write          = hwsampler_write,
110 };
111
112 static int oprofile_create_hwsampling_files(struct super_block *sb,
113                                                 struct dentry *root)
114 {
115         struct dentry *hw_dir;
116
117         /* reinitialize default values */
118         hwsampler_file = 1;
119
120         hw_dir = oprofilefs_mkdir(sb, root, "hwsampling");
121         if (!hw_dir)
122                 return -EINVAL;
123
124         oprofilefs_create_file(sb, hw_dir, "hwsampler", &hwsampler_fops);
125         oprofilefs_create_ulong(sb, hw_dir, "hw_interval",
126                                 &oprofile_hw_interval);
127         oprofilefs_create_ro_ulong(sb, hw_dir, "hw_min_interval",
128                                 &oprofile_min_interval);
129         oprofilefs_create_ro_ulong(sb, hw_dir, "hw_max_interval",
130                                 &oprofile_max_interval);
131         oprofilefs_create_ulong(sb, hw_dir, "hw_sdbt_blocks",
132                                 &oprofile_sdbt_blocks);
133
134         return 0;
135 }
136
137 static int oprofile_hwsampler_init(struct oprofile_operations *ops)
138 {
139         if (hwsampler_setup())
140                 return -ENODEV;
141
142         /*
143          * create hwsampler files only if hwsampler_setup() succeeds.
144          */
145         oprofile_min_interval = hwsampler_query_min_interval();
146         if (oprofile_min_interval == 0)
147                 return -ENODEV;
148         oprofile_max_interval = hwsampler_query_max_interval();
149         if (oprofile_max_interval == 0)
150                 return -ENODEV;
151
152         /* The initial value should be sane */
153         if (oprofile_hw_interval < oprofile_min_interval)
154                 oprofile_hw_interval = oprofile_min_interval;
155         if (oprofile_hw_interval > oprofile_max_interval)
156                 oprofile_hw_interval = oprofile_max_interval;
157
158         if (oprofile_timer_init(ops))
159                 return -ENODEV;
160
161         printk(KERN_INFO "oprofile: using hardware sampling\n");
162
163         memcpy(&timer_ops, ops, sizeof(timer_ops));
164
165         ops->start = oprofile_hwsampler_start;
166         ops->stop = oprofile_hwsampler_stop;
167         ops->create_files = oprofile_create_hwsampling_files;
168
169         return 0;
170 }
171
172 static void oprofile_hwsampler_exit(void)
173 {
174         oprofile_timer_exit();
175         hwsampler_shutdown();
176 }
177
178 #endif /* CONFIG_64BIT */
179
180 int __init oprofile_arch_init(struct oprofile_operations *ops)
181 {
182         ops->backtrace = s390_backtrace;
183
184 #ifdef CONFIG_64BIT
185         return oprofile_hwsampler_init(ops);
186 #else
187         return -ENODEV;
188 #endif
189 }
190
191 void oprofile_arch_exit(void)
192 {
193 #ifdef CONFIG_64BIT
194         oprofile_hwsampler_exit();
195 #endif
196 }