diff options
Diffstat (limited to 'arch/avr32/kernel/ocd.c')
| -rw-r--r-- | arch/avr32/kernel/ocd.c | 163 |
1 files changed, 163 insertions, 0 deletions
diff --git a/arch/avr32/kernel/ocd.c b/arch/avr32/kernel/ocd.c new file mode 100644 index 000000000000..c4f023294d75 --- /dev/null +++ b/arch/avr32/kernel/ocd.c @@ -0,0 +1,163 @@ +/* + * Copyright (C) 2007 Atmel Corporation + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ +#include <linux/init.h> +#include <linux/sched.h> +#include <linux/spinlock.h> + +#include <asm/ocd.h> + +static long ocd_count; +static spinlock_t ocd_lock; + +/** + * ocd_enable - enable on-chip debugging + * @child: task to be debugged + * + * If @child is non-NULL, ocd_enable() first checks if debugging has + * already been enabled for @child, and if it has, does nothing. + * + * If @child is NULL (e.g. when debugging the kernel), or debugging + * has not already been enabled for it, ocd_enable() increments the + * reference count and enables the debugging hardware. + */ +void ocd_enable(struct task_struct *child) +{ + u32 dc; + + if (child) + pr_debug("ocd_enable: child=%s [%u]\n", + child->comm, child->pid); + else + pr_debug("ocd_enable (no child)\n"); + + if (!child || !test_and_set_tsk_thread_flag(child, TIF_DEBUG)) { + spin_lock(&ocd_lock); + ocd_count++; + dc = ocd_read(DC); + dc |= (1 << OCD_DC_MM_BIT) | (1 << OCD_DC_DBE_BIT); + ocd_write(DC, dc); + spin_unlock(&ocd_lock); + } +} + +/** + * ocd_disable - disable on-chip debugging + * @child: task that was being debugged, but isn't anymore + * + * If @child is non-NULL, ocd_disable() checks if debugging is enabled + * for @child, and if it isn't, does nothing. + * + * If @child is NULL (e.g. when debugging the kernel), or debugging is + * enabled, ocd_disable() decrements the reference count, and if it + * reaches zero, disables the debugging hardware. + */ +void ocd_disable(struct task_struct *child) +{ + u32 dc; + + if (!child) + pr_debug("ocd_disable (no child)\n"); + else if (test_tsk_thread_flag(child, TIF_DEBUG)) + pr_debug("ocd_disable: child=%s [%u]\n", + child->comm, child->pid); + + if (!child || test_and_clear_tsk_thread_flag(child, TIF_DEBUG)) { + spin_lock(&ocd_lock); + ocd_count--; + + WARN_ON(ocd_count < 0); + + if (ocd_count <= 0) { + dc = ocd_read(DC); + dc &= ~((1 << OCD_DC_MM_BIT) | (1 << OCD_DC_DBE_BIT)); + ocd_write(DC, dc); + } + spin_unlock(&ocd_lock); + } +} + +#ifdef CONFIG_DEBUG_FS +#include <linux/debugfs.h> +#include <linux/module.h> + +static struct dentry *ocd_debugfs_root; +static struct dentry *ocd_debugfs_DC; +static struct dentry *ocd_debugfs_DS; +static struct dentry *ocd_debugfs_count; + +static u64 ocd_DC_get(void *data) +{ + return ocd_read(DC); +} +static void ocd_DC_set(void *data, u64 val) +{ + ocd_write(DC, val); +} +DEFINE_SIMPLE_ATTRIBUTE(fops_DC, ocd_DC_get, ocd_DC_set, "0x%08llx\n"); + +static u64 ocd_DS_get(void *data) +{ + return ocd_read(DS); +} +DEFINE_SIMPLE_ATTRIBUTE(fops_DS, ocd_DS_get, NULL, "0x%08llx\n"); + +static u64 ocd_count_get(void *data) +{ + return ocd_count; +} +DEFINE_SIMPLE_ATTRIBUTE(fops_count, ocd_count_get, NULL, "%lld\n"); + +static void ocd_debugfs_init(void) +{ + struct dentry *root; + + root = debugfs_create_dir("ocd", NULL); + if (IS_ERR(root) || !root) + goto err_root; + ocd_debugfs_root = root; + + ocd_debugfs_DC = debugfs_create_file("DC", S_IRUSR | S_IWUSR, + root, NULL, &fops_DC); + if (!ocd_debugfs_DC) + goto err_DC; + + ocd_debugfs_DS = debugfs_create_file("DS", S_IRUSR, root, + NULL, &fops_DS); + if (!ocd_debugfs_DS) + goto err_DS; + + ocd_debugfs_count = debugfs_create_file("count", S_IRUSR, root, + NULL, &fops_count); + if (!ocd_debugfs_count) + goto err_count; + + return; + +err_count: + debugfs_remove(ocd_debugfs_DS); +err_DS: + debugfs_remove(ocd_debugfs_DC); +err_DC: + debugfs_remove(ocd_debugfs_root); +err_root: + printk(KERN_WARNING "OCD: Failed to create debugfs entries\n"); +} +#else +static inline void ocd_debugfs_init(void) +{ + +} +#endif + +static int __init ocd_init(void) +{ + spin_lock_init(&ocd_lock); + ocd_debugfs_init(); + return 0; +} +arch_initcall(ocd_init); |