x86: Add debugfs entry for PAT memtype list

Index: linux-2.6/arch/x86/kernel/kdebugfs.c
===================================================================
@@ -12,9 +12,13 @@
 #include <linux/init.h>
 #include <linux/io.h>
 #include <linux/mm.h>
+#include <linux/module.h>
 
 #include <asm/setup.h>
 
+struct dentry *arch_debugfs_dir;
+EXPORT_SYMBOL(arch_debugfs_dir);
+
 #ifdef CONFIG_DEBUG_BOOT_PARAMS
 struct setup_data_node {
 	u64 paddr;

@@ -209,6 +213,10 @@ static int __init arch_kdebugfs_init(voi
 {
 	int error = 0;
 
+	arch_debugfs_dir = debugfs_create_dir("x86", NULL);
+	if (!arch_debugfs_dir)
+		return -ENOMEM;
+
 #ifdef CONFIG_DEBUG_BOOT_PARAMS
 	error = boot_params_kdebugfs_init();
 #endif

Index: linux-2.6/include/linux/debugfs.h
===================================================================
@@ -26,6 +26,8 @@ struct debugfs_blob_wrapper {
 	unsigned long size;
 };
 
+extern struct dentry *arch_debugfs_dir;
+
 #if defined(CONFIG_DEBUG_FS)
 
 /* declared over in file.c */

Index: linux-2.6/arch/x86/mm/pat.c
===================================================================
@@ -12,6 +12,8 @@
 #include <linux/gfp.h>
 #include <linux/fs.h>
 #include <linux/bootmem.h>
+#include <linux/debugfs.h>
+#include <linux/seq_file.h>
 
 #include <asm/msr.h>
 #include <asm/tlbflush.h>

@@ -489,3 +491,89 @@ void unmap_devmem(unsigned long pfn, uns
 
 	free_memtype(addr, addr + size);
 }
+
+#if defined(CONFIG_DEBUG_FS)
+
+/* get Nth element of the linked list */
+static struct memtype *memtype_get_idx(loff_t pos)
+{
+	struct memtype *list_node, *print_entry;
+	int i = 1;
+
+	print_entry  = kmalloc(sizeof(struct memtype), GFP_KERNEL);
+	if (!print_entry)
+		return NULL;
+
+	spin_lock(&memtype_lock);
+	list_for_each_entry(list_node, &memtype_list, nd) {
+		if (pos == i) {
+			*print_entry = *list_node;
+			spin_unlock(&memtype_lock);
+			return print_entry;
+		}
+		++i;
+	}
+	spin_unlock(&memtype_lock);
+	kfree(print_entry);
+	return NULL;
+}
+
+static void *memtype_seq_start(struct seq_file *seq, loff_t *pos)
+{
+	if (*pos == 0) {
+		++*pos;
+		seq_printf(seq, "PAT memtype list:\n");
+	}
+
+	return memtype_get_idx(*pos);
+}
+
+static void *memtype_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+	++*pos;
+	return memtype_get_idx(*pos);
+}
+
+static void memtype_seq_stop(struct seq_file *seq, void *v)
+{
+}
+
+static int memtype_seq_show(struct seq_file *seq, void *v)
+{
+	struct memtype *print_entry = (struct memtype *)v;
+
+	seq_printf(seq, "%s @ 0x%Lx-0x%Lx\n", cattr_name(print_entry->type),
+			print_entry->start, print_entry->end);
+	kfree(print_entry);
+	return 0;
+}
+
+static struct seq_operations memtype_seq_ops = {
+	.start = memtype_seq_start,
+	.next  = memtype_seq_next,
+	.stop  = memtype_seq_stop,
+	.show  = memtype_seq_show,
+};
+
+static int memtype_seq_open(struct inode *inode, struct file *file)
+{
+	return seq_open(file, &memtype_seq_ops);
+}
+
+static const struct file_operations memtype_fops = {
+	.open    = memtype_seq_open,
+	.read    = seq_read,
+	.llseek  = seq_lseek,
+	.release = seq_release,
+};
+
+static int __init pat_memtype_list_init(void)
+{
+	debugfs_create_file("pat_memtype_list", S_IRUSR, arch_debugfs_dir,
+				NULL, &memtype_fops);
+	return 0;
+}
+
+late_initcall(pat_memtype_list_init);
+
+#endif /* CONFIG_DEBUG_FS */