/*
 * core function to access sclp interface
 *
 * Copyright IBM Corp. 1999, 2009
 *
 * Author(s): Martin Peschke <mpeschke@de.ibm.com>
 *	      Martin Schwidefsky <schwidefsky@de.ibm.com>
 */

#include <linux/kernel_stat.h>
#include <linux/module.h>
#include <linux/err.h>
#include <linux/spinlock.h>
#include <linux/interrupt.h>
#include <linux/timer.h>
#include <linux/reboot.h>
#include <linux/jiffies.h>
#include <linux/init.h>
#include <linux/suspend.h>
#include <linux/completion.h>
#include <linux/platform_device.h>
#include <asm/types.h>
#include <asm/irq.h>

#include "sclp.h"

#define SCLP_HEADER		"sclp: "

/* Lock to protect internal data consistency. */
static DEFINE_SPINLOCK(sclp_lock);

/* Mask of events that we can send to the sclp interface. */
static sccb_mask_t sclp_receive_mask;

/* Mask of events that we can receive from the sclp interface. */
static sccb_mask_t sclp_send_mask;

/* List of registered event listeners and senders. */
static struct list_head sclp_reg_list;

/* List of queued requests. */
static struct list_head sclp_req_queue;

/* Data for read and and init requests. */
static struct sclp_req sclp_read_req;
static struct sclp_req sclp_init_req;
static char sclp_read_sccb[PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE)));
static char sclp_init_sccb[PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE)));

/* Suspend request */
static DECLARE_COMPLETION(sclp_request_queue_flushed);

/* Number of console pages to allocate, used by sclp_con.c and sclp_vt220.c */
int sclp_console_pages = SCLP_CONSOLE_PAGES;
/* Flag to indicate if buffer pages are dropped on buffer full condition */
int sclp_console_drop = 0;
/* Number of times the console dropped buffer pages */
unsigned long sclp_console_full;

static void sclp_suspend_req_cb(struct sclp_req *req, void *data)
{
	complete(&sclp_request_queue_flushed);
}

static int __init sclp_setup_console_pages(char *str)
{
	int pages, rc;

	rc = kstrtoint(str, 0, &pages);
	if (!rc && pages >= SCLP_CONSOLE_PAGES)
		sclp_console_pages = pages;
	return 1;
}

__setup("sclp_con_pages=", sclp_setup_console_pages);

static int __init sclp_setup_console_drop(char *str)
{
	int drop, rc;

	rc = kstrtoint(str, 0, &drop);
	if (!rc && drop)
		sclp_console_drop = 1;
	return 1;
}

__setup("sclp_con_drop=", sclp_setup_console_drop);

static struct sclp_req sclp_suspend_req;

/* Timer for request retries. */
static struct timer_list sclp_request_timer;

/* Timer for queued requests. */
static struct timer_list sclp_queue_timer;

/* Internal state: is the driver initialized? */
static volatile enum sclp_init_state_t {
	sclp_init_state_uninitialized,
	sclp_init_state_initializing,
	sclp_init_state_initialized
} sclp_init_state = sclp_init_state_uninitialized;

/* Internal state: is a request active at the sclp? */
static volatile enum sclp_running_state_t {
	sclp_running_state_idle,
	sclp_running_state_running,
	sclp_running_state_reset_pending
} sclp_running_state = sclp_running_state_idle;

/* Internal state: is a read request pending? */
static volatile enum sclp_reading_state_t {
	sclp_reading_state_idle,
	sclp_reading_state_reading
} sclp_reading_state = sclp_reading_state_idle;

/* Internal state: is the driver currently serving requests? */
static volatile enum