1 files changed, 79 insertions, 0 deletions

diff --git a/arch/sh/mm/asids-debugfs.c b/arch/sh/mm/asids-debugfs.c
new file mode 100644
index 000000000000..0678a1044a9a
--- /dev/null
+++ b/arch/sh/mm/asids-debugfs.c
@@ -0,0 +1,79 @@
+/*
+ * debugfs ops for process ASIDs
+ *
+ *  Copyright (C) 2000, 2001  Paolo Alberelli
+ *  Copyright (C) 2003 - 2008  Paul Mundt
+ *  Copyright (C) 2003, 2004  Richard Curnow
+ *
+ * Provides a debugfs file that lists out the ASIDs currently associated
+ * with the processes.
+ *
+ * In the SH-5 case, if the DM.PC register is examined through the debug
+ * link, this shows ASID + PC. To make use of this, the PID->ASID
+ * relationship needs to be known. This is primarily for debugging.
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/debugfs.h>
+#include <linux/seq_file.h>
+#include <linux/spinlock.h>
+#include <asm/processor.h>
+#include <asm/mmu_context.h>
+
+static int asids_seq_show(struct seq_file *file, void *iter)
+{
+        struct task_struct *p;
+
+        read_lock(&tasklist_lock);
+
+        for_each_process(p) {
+                int pid = p->pid;
+
+                if (unlikely(!pid))
+                        continue;
+
+                if (p->mm)
+                        seq_printf(file, "%5d : %02x\n", pid,
+                                   cpu_asid(smp_processor_id(), p->mm));
+                else
+                        seq_printf(file, "%5d : (none)\n", pid);
+        }
+
+        read_unlock(&tasklist_lock);
+
+        return 0;
+}
+
+static int asids_debugfs_open(struct inode *inode, struct file *file)
+{
+        return single_open(file, asids_seq_show, inode->i_private);
+}
+
+static const struct file_operations asids_debugfs_fops = {
+        .owner          = THIS_MODULE,
+        .open           = asids_debugfs_open,
+        .read           = seq_read,
+        .llseek         = seq_lseek,
+        .release        = single_release,
+};
+
+static int __init asids_debugfs_init(void)
+{
+        struct dentry *asids_dentry;
+
+        asids_dentry = debugfs_create_file("asids", S_IRUSR, sh_debugfs_root,
+                                           NULL, &asids_debugfs_fops);
+        if (!asids_dentry)
+                return -ENOMEM;
+        if (IS_ERR(asids_dentry))
+                return PTR_ERR(asids_dentry);
+
+        return 0;
+}
+module_init(asids_debugfs_init);
+
+MODULE_LICENSE("GPL v2");