/* arch/arm/mach-msm/rpc_servers.c
 *
 * Copyright (C) 2007 Google, Inc.
 * Author: Iliyan Malchev <ibm@android.com>
 *
 * This software is licensed under the terms of the GNU General Public
 * License version 2, as published by the Free Software Foundation, and
 * may be copied, distributed, and modified under those terms.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/cdev.h>
#include <linux/init.h>
#include <linux/device.h>
#include <linux/types.h>
#include <linux/fs.h>
#include <linux/kthread.h>
#include <linux/delay.h>
#include <linux/platform_device.h>
#include <linux/wakelock.h>
#include <linux/slab.h>

#include <linux/msm_rpcrouter.h>
#include <linux/uaccess.h>

#include <mach/msm_rpcrouter.h>
#include "smd_rpcrouter.h"

static struct msm_rpc_endpoint *endpoint;

#define FLAG_REGISTERED 0x0001

static LIST_HEAD(rpc_server_list);
static DEFINE_MUTEX(rpc_server_list_lock);
static int rpc_servers_active;
static struct wake_lock rpc_servers_wake_lock;

static void rpc_server_register(struct msm_rpc_server *server)
{
	int rc;
	rc = msm_rpc_register_server(endpoint, server->prog, server->vers);
	if (rc < 0)
		printk(KERN_ERR "[rpcserver] error registering %p @ %08x:%d\n",
		       server, server->prog, server->vers);
}

static struct msm_rpc_server *rpc_server_find(uint32_t prog, uint32_t vers)
{
	struct msm_rpc_server *server;

	mutex_lock(&rpc_server_list_lock);
	list_for_each_entry(server, &rpc_server_list, list) {
		if ((server->prog == prog) &&
#if CONFIG_MSM_AMSS_VERSION >= 6350
		    msm_rpc_is_compatible_version(server->vers, vers)) {
#else
		    server->vers == vers) {
#endif
			mutex_unlock(&rpc_server_list_lock);
			return server;
		}
	}
	mutex_unlock(&rpc_server_list_lock);
	return NULL;
}

static void rpc_server_register_all(void)
{
	struct msm_rpc_server *server;

	mutex_lock(&rpc_server_list_lock);
	list_for_each_entry(server, &rpc_server_list, list) {
		if (!(server->flags & FLAG_REGISTERED)) {
			rpc_server_register(server);
			server->flags |= FLAG_REGISTERED;
		}
	}
	mutex_unlock(&rpc_server_list_lock);
}

int msm_rpc_create_server(struct msm_rpc_server *server)
{
	/* make sure we're in a sane state first */
	server->flags = 0;
	INIT_LIST_HEAD(&server->list);

	mutex_lock(&rpc_server_list_lock);
	list_add(&server->list, &rpc_server_list);
	if (rpc_servers_active) {
		rpc_server_register(server);
		server->flags |= FLAG_REGISTERED;
	}
	mutex_unlock(&rpc_server_list_lock);

	return 0;
}

static int rpc_send_accepted_void_reply(struct msm_rpc_endpoint *client,
					uint32_t xid, uint32_t accept_status)
{
	int rc = 0;
	uint8_t reply_buf[sizeof(struct rpc_reply_hdr)];
	struct rpc_reply_hdr *reply = (struct rpc_reply_hdr *)reply_buf;

	reply->xid = cpu_to_be32(xid);
	reply->type = cpu_to_be32(1); /* reply */
	reply->reply_stat = cpu_to_be32(RPCMSG_REPLYSTAT_ACCEPTED);

	reply->data.acc_hdr.accept_stat = cpu_to_be32(accept_status);
	reply->data.acc_hdr.verf_flavor = 0;
	reply->data.acc_hdr.verf_length = 0;

	rc = msm_rpc_write(client, reply_buf, sizeof(reply_buf));
	if (rc < 0)
		printk(KERN_ERR
		       "%s: could not write response: %d\n",
		       __FUNCTION__, rc);

	return rc;
}

static int rpc_servers_thread(void *data)
{
	void *buffer;
	struct rpc_request_hdr *req;
	struct msm_rpc_server *server;
	int rc;

	for (;;) {
		wake_unlock(&rpc_servers_wake_lock);
		rc = wait_event_interruptible(endpoint->wait_q,
						!list_empty(&endpoint->read_q));
		wake_lock(&rpc_servers_wake_lock);
		rc = msm_rpc_read(endpoint, &buffer, -1, -1);
		if (rc < 0) {
			printk(KERN_ERR "%s: could not read: %d\n",
			       __FUNCTION__, rc);
			break;
		}
		req = (struct rpc_request_hdr *)buffer;

		req->type = be32_to_cpu(req->type);
		req->xid = be32_to_cpu(req->xid);
		req->rpc_vers = be32_to_cpu(req->rpc_vers);
		req->prog = be32_to_cpu(req->prog);
		req->vers = be32_to_cpu(req->vers);
		req->procedure = be32_to_cpu(req->procedure);

		server = rpc_server_find(req->prog, req->vers);

		if (req->rpc_vers != 2)
			continue;
		if (req->type != 0)
			continue;
		if (!server) {
			rpc_send_accepted_void_reply(
				endpoint, req->xid,
				RPC_ACCEPTSTAT_PROG_UNAVAIL);
			continue;
		}

		rc = server->rpc_call(server, req, rc);

		switch (rc) {
		case 0:
			rpc_send_accepted_void_reply(
				endpoint, req->xid,
				RPC_ACCEPTSTAT_SUCCESS);
			break;
		default:
			rpc_send_accepted_void_reply(
				endpoint, req->xid,
				RPC_ACCEPTSTAT_PROG_UNAVAIL);
			break;
		}

		kfree(buffer);
	}

	do_exit(0);
}

static int rpcservers_probe(struct platform_device *pdev)
{
	struct task_struct *server_thread;

	endpoint = msm_rpc_open();
	if (IS_ERR(endpoint))
		return PTR_ERR(endpoint);

	/* we're online -- register any servers installed beforehand */
	rpc_servers_active = 1;
	rpc_server_register_all();

	/* start the kernel thread */
	server_thread = kthread_run(rpc_servers_thread, NULL, "krpcserversd");
	if (IS_ERR(server_thread))
		return PTR_ERR(server_thread);

	return 0;
}

static struct platform_driver rpcservers_driver = {
	.probe	= rpcservers_probe,
	.driver	= {
		.name	= "oncrpc_router",
		.owner	= THIS_MODULE,
	},
};

static int __init rpc_servers_init(void)
{
	wake_lock_init(&rpc_servers_wake_lock, WAKE_LOCK_SUSPEND, "rpc_server");
	return platform_driver_register(&rpcservers_driver);
}

module_init(rpc_servers_init);

MODULE_DESCRIPTION("MSM RPC Servers");
MODULE_AUTHOR("Iliyan Malchev <ibm@android.com>");
MODULE_LICENSE("GPL");