// SPDX-License-Identifier: GPL-2.0-only

#include <linux/module.h>
#include <linux/init.h>
#include <linux/seq_file.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/proc_fs.h>

#include <asm/sysreg.h>

static int ttbr1_show(struct seq_file *m, void *v)
{
	unsigned long ttbr;
	int cpu;

	preempt_disable();
	cpu = smp_processor_id();
	ttbr = read_sysreg(ttbr1_el1);
	preempt_enable();

	seq_printf(m, "CPU%u: TTBR1 0x%08lx\n", cpu, ttbr);

	return 0;
}

static int ttbr1_open(struct inode *inode, struct file *file)
{
	return single_open(file, ttbr1_show, NULL);
}

static const struct proc_ops ttbr1_fops = {
	.proc_open	= ttbr1_open,
	.proc_read	= seq_read,
	.proc_lseek	= seq_lseek,
	.proc_release	= single_release,
};

extern const char ktext_nid[32];

static int nid_show(struct seq_file *m, void *v)
{
	int cpu;

	preempt_disable();
	cpu = smp_processor_id();
	seq_printf(m, "CPU%u: nid %s\n",
		   cpu, ktext_nid);
	preempt_enable();


	return 0;
}

static int nid_open(struct inode *inode, struct file *file)
{
	return single_open(file, nid_show, NULL);
}

static const struct proc_ops nid_fops = {
	.proc_open	= nid_open,
	.proc_read	= seq_read,
	.proc_lseek	= seq_lseek,
	.proc_release	= single_release,
};

static int ttbr1_init(void)
{
	struct proc_dir_entry *dir;

	dir = proc_mkdir("ktext", NULL);
	if (!dir)
		return -ENOMEM;

	if (!proc_create("ttbr1", S_IRUSR, dir, &ttbr1_fops) ||
	    !proc_create("text_nid", S_IRUSR, dir, &nid_fops)) {
		remove_proc_subtree("ktext", NULL);
		return -ENOMEM;
	}

	return 0;
}
module_init(ttbr1_init);

static void ttbr1_fin(void)
{
	remove_proc_subtree("ktext", NULL);
}
module_exit(ttbr1_fin);

MODULE_AUTHOR("Russell King");
MODULE_LICENSE("GPL");