path: root/drivers/s390/cio/cio.c

/*
 *  drivers/s390/cio/cio.c
 *   S/390 common I/O routines -- low level i/o calls
 *
 *    Copyright (C) 1999-2002 IBM Deutschland Entwicklung GmbH,
 *			      IBM Corporation
 *    Author(s): Ingo Adlung (adlung@de.ibm.com)
 *		 Cornelia Huck (cornelia.huck@de.ibm.com)
 *		 Arnd Bergmann (arndb@de.ibm.com)
 *		 Martin Schwidefsky (schwidefsky@de.ibm.com)
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/device.h>
#include <linux/kernel_stat.h>
#include <linux/interrupt.h>
#include <asm/cio.h>
#include <asm/delay.h>
#include <asm/irq.h>
#include <asm/setup.h>
#include "airq.h"
#include "cio.h"
#include "css.h"
#include "chsc.h"
#include "ioasm.h"
#include "blacklist.h"
#include "cio_debug.h"

debug_info_t *cio_debug_msg_id;
debug_info_t *cio_debug_trace_id;
debug_info_t *cio_debug_crw_id;

int cio_show_msg;

static int __init
cio_setup (char *parm)
{
	if (!strcmp (parm, "yes"))
		cio_show_msg = 1;
	else if (!strcmp (parm, "no"))
		cio_show_msg = 0;
	else
		printk (KERN_ERR "cio_setup : invalid cio_msg parameter '%s'",
			parm);
	return 1;
}

__setup ("cio_msg=", cio_setup);

/*
 * Function: cio_debug_init
 * Initializes three debug logs (under /proc/s390dbf) for common I/O:
 * - cio_msg logs the messages which are printk'ed when CONFIG_DEBUG_IO is on
 * - cio_trace logs the calling of different functions
 * - cio_crw logs the messages which are printk'ed when CONFIG_DEBUG_CRW is on
 * debug levels depend on CONFIG_DEBUG_IO resp. CONFIG_DEBUG_CRW
 */
static int __init
cio_debug_init (void)
{
	cio_debug_msg_id = debug_register ("cio_msg", 16, 4, 16*sizeof (long));
	if (!cio_debug_msg_id)
		goto out_unregister;
	debug_register_view (cio_debug_msg_id, &debug_sprintf_view);
	debug_set_level (cio_debug_msg_id, 2);
	cio_debug_trace_id = debug_register ("cio_trace", 16, 4, 16);
	if (!cio_debug_trace_id)
		goto out_unregister;
	debug_register_view (cio_debug_trace_id, &debug_hex_ascii_view);
	debug_set_level (cio_debug_trace_id, 2);
	cio_debug_crw_id = debug_register ("cio_crw", 4, 4, 16*sizeof (long));
	if (!cio_debug_crw_id)
		goto out_unregister;
	debug_register_view (cio_debug_crw_id, &debug_sprintf_view);
	debug_set_level (cio_debug_crw_id, 2);
	pr_debug("debugging initialized\n");
	return 0;

out_unregister:
	if (cio_debug_msg_id)
		debug_unregister (cio_debug_msg_id);
	if (cio_debug_trace_id)
		debug_unregister (cio_debug_trace_id);
	if (cio_debug_crw_id)
		debug_unregister (cio_debug_crw_id);
	pr_debug("could not initialize debugging\n");
	return -1;
}

arch_initcall (cio_debug_init);

int
cio_set_options (struct subchannel *sch, int flags)
{
       sch->options.suspend = (flags & DOIO_ALLOW_SUSPEND) != 0;
       sch->options.prefetch = (flags & DOIO_DENY_PREFETCH) != 0;
       sch->options.inter = (flags & DOIO_SUPPRESS_INTER) != 0;
       return 0;
}

/* FIXME: who wants to use this? */
int
cio_get_options (struct subchannel *sch)
{
       int flags;

       flags = 0;
       if (sch->options.suspend)
		flags |= DOIO_ALLOW_SUSPEND;
       if (sch->options.prefetch)
		flags |= DOIO_DENY_PREFETCH;
       if (sch->options.inter)
		flags |= DOIO_SUPPRESS_INTER;
       return flags;
}

/*
 * Use tpi to get a pending interrupt, call the interrupt handler and
 * return a pointer to the subchannel structure.
 */
static inline int
cio_tpi(void)
{
	struct tpi_info *tpi_info;
	struct subchannel *sch;
	struct irb *irb;

	tpi_info = (struct tpi_info *) __LC_SUBCHANNEL_ID;
	if (tpi (NULL) != 1)
		return 0;
	irb = (struct irb *) __LC_IRB;
	/* Store interrupt response block to lowcore. */
	if (tsch (tpi_info->schid, irb) != 0)
		/* Not status pending or not operational. */
		return 1;
	sch = (struct subchannel *)(unsigned long)tpi_info->intparm;
	if (!sch)
		return 1;
	local_bh_disable();
	irq_enter ();
	spin_lock(&sch->lock);
	memcpy (&sch->schib.scsw, &irb->scsw, sizeof (struct scsw));
	if (sch->driver && sch->driver->irq)
		sch->driver->irq(&sch->dev);
	spin_unlock(&sch->lock);
	irq_exit ();
	_local_bh_enable();
	return 1;
}

static inline int
cio_start_handle_notoper(struct subchannel *sch, __u8 lpm)
{
	char dbf_text[15];

	if (lpm != 0)
		sch->lpm &= ~lpm;
	else
		sch->lpm = 0;

	stsch (sch->schid, &sch->schib);