// SPDX-License-Identifier: GPL-2.0+
/* Copyright (C) 2022 AVM GmbH <fritzbox_info@avm.de> */

#define pr_fmt(fmt) "mrpc/avm_crashlog_server: " fmt

#include "avm_crashlog_mrpc.h"
#include <linux/semaphore.h>
#include <linux/module.h>
#include <linux/mrpc.h>
#include <avm/watchdog/watchdog.h>
#include <avm/tffs/tffs.h>

#ifdef CONFIG_TFFS_REMOTE_CRASHLOG_WRITER
static int crashlog_server_sem_down(void *arg, ssize_t arglen, void *rep,
		ssize_t replen)
{
	down(&tffs_log_sema);

	return 0;
}

static int crashlog_server_sem_up(void *arg, ssize_t arglen, void *rep,
		ssize_t replen)
{
	up(&tffs_log_sema);

	return 0;
}
#endif /* CONFIG_TFFS_REMOTE_CRASHLOG_WRITER */

#ifdef CONFIG_TFFS_REMOTE_CRASHLOG_READER
static int crashlog_server_is_read_forbidden(void *arg, ssize_t arglen,
		void *rep, ssize_t replen)
{
	int forbidden, *ret = rep;

	down(&tffs_log_sema);

	forbidden = AVM_WATCHDOG_Crashlog_read_forbidden();
	*ret = cpu_to_be32(forbidden);

	pr_devel("[%s] forbidden=%d\n", __func__, forbidden);

	up(&tffs_log_sema);

	return 0;
}
#endif /* CONFIG_TFFS_REMOTE_CRASHLOG_READER */

static struct mrpc_procinfo crashlog_server_procs[] = {
	/* request, handle function, arg length, reply length */
#ifdef CONFIG_TFFS_REMOTE_CRASHLOG_WRITER
	MRPC_PROCINFO_ENTRY(MRPC_AVM_CRASHLOG_PROC_SEM_DOWN,
			 crashlog_server_sem_down,
			 0,
			 0),
	MRPC_PROCINFO_ENTRY(MRPC_AVM_CRASHLOG_PROC_SEM_UP,
			 crashlog_server_sem_up,
			 0,
			 0),
#endif
#ifdef CONFIG_TFFS_REMOTE_CRASHLOG_READER
	MRPC_PROCINFO_ENTRY(MRPC_AVM_CRASHLOG_PROC_IS_READ_FORBIDDEN,
			 crashlog_server_is_read_forbidden,
			 0,
			 sizeof(int)),
#endif
};

static int crashlog_server_init(void)
{
	struct mrpc_server *server;

	server = mrpc_server_register(
		MRPC_RESERVED_ID_AVM_CRASHLOG,
		"AVM crashlog server",
		crashlog_server_procs,
		ARRAY_SIZE(crashlog_server_procs));

	if (!server)
		return -ENODEV;

	return 0;
}
static_notifier_module_init(mrpc_ready, crashlog_server_init);