2 * Copyright (C) 2007 Atmel Corporation
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
8 #include <linux/init.h>
9 #include <linux/sched.h>
10 #include <linux/spinlock.h>
14 static long ocd_count
;
15 static spinlock_t ocd_lock
;
18 * ocd_enable - enable on-chip debugging
19 * @child: task to be debugged
21 * If @child is non-NULL, ocd_enable() first checks if debugging has
22 * already been enabled for @child, and if it has, does nothing.
24 * If @child is NULL (e.g. when debugging the kernel), or debugging
25 * has not already been enabled for it, ocd_enable() increments the
26 * reference count and enables the debugging hardware.
28 void ocd_enable(struct task_struct
*child
)
33 pr_debug("ocd_enable: child=%s [%u]\n",
34 child
->comm
, child
->pid
);
36 pr_debug("ocd_enable (no child)\n");
38 if (!child
|| !test_and_set_tsk_thread_flag(child
, TIF_DEBUG
)) {
42 dc
|= (1 << OCD_DC_MM_BIT
) | (1 << OCD_DC_DBE_BIT
);
44 spin_unlock(&ocd_lock
);
49 * ocd_disable - disable on-chip debugging
50 * @child: task that was being debugged, but isn't anymore
52 * If @child is non-NULL, ocd_disable() checks if debugging is enabled
53 * for @child, and if it isn't, does nothing.
55 * If @child is NULL (e.g. when debugging the kernel), or debugging is
56 * enabled, ocd_disable() decrements the reference count, and if it
57 * reaches zero, disables the debugging hardware.
59 void ocd_disable(struct task_struct
*child
)
64 pr_debug("ocd_disable (no child)\n");
65 else if (test_tsk_thread_flag(child
, TIF_DEBUG
))
66 pr_debug("ocd_disable: child=%s [%u]\n",
67 child
->comm
, child
->pid
);
69 if (!child
|| test_and_clear_tsk_thread_flag(child
, TIF_DEBUG
)) {
73 WARN_ON(ocd_count
< 0);
77 dc
&= ~((1 << OCD_DC_MM_BIT
) | (1 << OCD_DC_DBE_BIT
));
80 spin_unlock(&ocd_lock
);
84 #ifdef CONFIG_DEBUG_FS
85 #include <linux/debugfs.h>
86 #include <linux/module.h>
88 static struct dentry
*ocd_debugfs_root
;
89 static struct dentry
*ocd_debugfs_DC
;
90 static struct dentry
*ocd_debugfs_DS
;
91 static struct dentry
*ocd_debugfs_count
;
93 static u64
ocd_DC_get(void *data
)
97 static void ocd_DC_set(void *data
, u64 val
)
101 DEFINE_SIMPLE_ATTRIBUTE(fops_DC
, ocd_DC_get
, ocd_DC_set
, "0x%08llx\n");
103 static u64
ocd_DS_get(void *data
)
107 DEFINE_SIMPLE_ATTRIBUTE(fops_DS
, ocd_DS_get
, NULL
, "0x%08llx\n");
109 static u64
ocd_count_get(void *data
)
113 DEFINE_SIMPLE_ATTRIBUTE(fops_count
, ocd_count_get
, NULL
, "%lld\n");
115 static void ocd_debugfs_init(void)
119 root
= debugfs_create_dir("ocd", NULL
);
120 if (IS_ERR(root
) || !root
)
122 ocd_debugfs_root
= root
;
124 ocd_debugfs_DC
= debugfs_create_file("DC", S_IRUSR
| S_IWUSR
,
125 root
, NULL
, &fops_DC
);
129 ocd_debugfs_DS
= debugfs_create_file("DS", S_IRUSR
, root
,
134 ocd_debugfs_count
= debugfs_create_file("count", S_IRUSR
, root
,
136 if (!ocd_debugfs_count
)
142 debugfs_remove(ocd_debugfs_DS
);
144 debugfs_remove(ocd_debugfs_DC
);
146 debugfs_remove(ocd_debugfs_root
);
148 printk(KERN_WARNING
"OCD: Failed to create debugfs entries\n");
151 static inline void ocd_debugfs_init(void)
157 static int __init
ocd_init(void)
159 spin_lock_init(&ocd_lock
);
163 arch_initcall(ocd_init
);