--- /dev/null
+/*
+ * 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);
git://ftp.safe.ca / safe / jmp / linux-2.6 / commitdiff