2 * arch/s390/oprofile/init.c
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)
10 * @remark Copyright 2002-2011 OProfile authors
13 #include <linux/oprofile.h>
14 #include <linux/init.h>
15 #include <linux/errno.h>
18 #include "../../../drivers/oprofile/oprof.h"
20 extern void s390_backtrace(struct pt_regs * const regs, unsigned int depth);
24 #include "hwsampler.h"
26 #define DEFAULT_INTERVAL 4127518
28 #define DEFAULT_SDBT_BLOCKS 1
29 #define DEFAULT_SDB_BLOCKS 511
31 static unsigned long oprofile_hw_interval = DEFAULT_INTERVAL;
32 static unsigned long oprofile_min_interval;
33 static unsigned long oprofile_max_interval;
35 static unsigned long oprofile_sdbt_blocks = DEFAULT_SDBT_BLOCKS;
36 static unsigned long oprofile_sdb_blocks = DEFAULT_SDB_BLOCKS;
38 static int hwsampler_file;
39 static int hwsampler_running; /* start_mutex must be held to change */
41 static struct oprofile_operations timer_ops;
43 static int oprofile_hwsampler_start(void)
47 hwsampler_running = hwsampler_file;
49 if (!hwsampler_running)
50 return timer_ops.start();
52 retval = hwsampler_allocate(oprofile_sdbt_blocks, oprofile_sdb_blocks);
56 retval = hwsampler_start_all(oprofile_hw_interval);
58 hwsampler_deallocate();
63 static void oprofile_hwsampler_stop(void)
65 if (!hwsampler_running) {
71 hwsampler_deallocate();
75 static ssize_t hwsampler_read(struct file *file, char __user *buf,
76 size_t count, loff_t *offset)
78 return oprofilefs_ulong_to_user(hwsampler_file, buf, count, offset);
81 static ssize_t hwsampler_write(struct file *file, char const __user *buf,
82 size_t count, loff_t *offset)
90 retval = oprofilefs_ulong_from_user(&val, buf, count);
96 * save to do without locking as we set
97 * hwsampler_running in start() when start_mutex is
102 hwsampler_file = val;
107 static const struct file_operations hwsampler_fops = {
108 .read = hwsampler_read,
109 .write = hwsampler_write,
112 static int oprofile_create_hwsampling_files(struct super_block *sb,
115 struct dentry *hw_dir;
117 /* reinitialize default values */
120 hw_dir = oprofilefs_mkdir(sb, root, "hwsampling");
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);
137 static int oprofile_hwsampler_init(struct oprofile_operations *ops)
139 if (hwsampler_setup())
143 * create hwsampler files only if hwsampler_setup() succeeds.
145 oprofile_min_interval = hwsampler_query_min_interval();
146 if (oprofile_min_interval == 0)
148 oprofile_max_interval = hwsampler_query_max_interval();
149 if (oprofile_max_interval == 0)
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;
158 if (oprofile_timer_init(ops))
161 printk(KERN_INFO "oprofile: using hardware sampling\n");
163 memcpy(&timer_ops, ops, sizeof(timer_ops));
165 ops->start = oprofile_hwsampler_start;
166 ops->stop = oprofile_hwsampler_stop;
167 ops->create_files = oprofile_create_hwsampling_files;
172 static void oprofile_hwsampler_exit(void)
174 oprofile_timer_exit();
175 hwsampler_shutdown();
178 #endif /* CONFIG_64BIT */
180 int __init oprofile_arch_init(struct oprofile_operations *ops)
182 ops->backtrace = s390_backtrace;
185 return oprofile_hwsampler_init(ops);
191 void oprofile_arch_exit(void)
194 oprofile_hwsampler_exit();