cio.c

优龙2410linux2.6.8内核源代码

/*
 *  drivers/s390/cio/cio.c
 *   S/390 common I/O routines -- low level i/o calls
 *   $Revision: 1.123 $
 *
 *    Copyright (C) 1999-2002 IBM Deutschland Entwicklung GmbH,
 *			      IBM Corporation
 *    Author(s): Ingo Adlung ([e-mail])
 *		 Cornelia Huck ([e-mail])
 *		 Arnd Bergmann ([e-mail])
 *		 Martin Schwidefsky ([e-mail])
 */

#include <linux/module.h>
#include <linux/config.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/device.h>
#include <linux/kernel_stat.h>

#include <asm/hardirq.h>
#include <asm/cio.h>
#include <asm/delay.h>
#include <asm/irq.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", 4, 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", 4, 4, 8);
	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", 2, 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->irq, irb) != 0)
		/* Not status pending or not operational. */
		return 1;
	sch = (struct subchannel *)(unsigned long)tpi_info->intparm;
	if (!sch)
		return 1;
	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 ();
	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->irq, &sch->schib);

	CIO_MSG_EVENT(0, "cio_start: 'not oper' status for "
		      "subchannel %04x!\n", sch->irq);
	sprintf(dbf_text, "no%s", sch->dev.bus_id);
	CIO_TRACE_EVENT(0, dbf_text);
	CIO_HEX_EVENT(0, &sch->schib, sizeof (struct schib));

	return (sch->lpm ? -EACCES : -ENODEV);
}

int
cio_start (struct subchannel *sch,	/* subchannel structure */
	   struct ccw1 * cpa,		/* logical channel prog addr */
	   __u8 lpm)			/* logical path mask */
{
	char dbf_txt[15];
	int ccode;

	CIO_TRACE_EVENT (4, "stIO");
	CIO_TRACE_EVENT (4, sch->dev.bus_id);

	/* sch is always under 2G. */
	sch->orb.intparm = (__u32)(unsigned long)sch;
	sch->orb.fmt = 1;

	sch->orb.pfch = sch->options.prefetch == 0;
	sch->orb.spnd = sch->options.suspend;
	sch->orb.ssic = sch->options.suspend && sch->options.inter;
	sch->orb.lpm = (lpm != 0) ? (lpm & sch->opm) : sch->lpm;
#ifdef CONFIG_ARCH_S390X
	/*
	 * for 64 bit we always support 64 bit IDAWs with 4k page size only
	 */
	sch->orb.c64 = 1;
	sch->orb.i2k = 0;
#endif
	sch->orb.cpa = (__u32) __pa (cpa);

	/*
	 * Issue "Start subchannel" and process condition code
	 */
	ccode = ssch (sch->irq, &sch->orb);
	sprintf (dbf_txt, "ccode:%d", ccode);
	CIO_TRACE_EVENT (4, dbf_txt);

	switch (ccode) {
	case 0:
		/*
		 * initialize device status information
		 */
		sch->schib.scsw.actl |= SCSW_ACTL_START_PEND;
		return 0;
	case 1:		/* status pending */
	case 2:		/* busy */
		return -EBUSY;
	default:		/* device/path not operational */
		return cio_start_handle_notoper(sch, lpm);
	}
}

/*
 * resume suspended I/O operation
 */
int
cio_resume (struct subchannel *sch)
{
	char dbf_txt[15];
	int ccode;

	CIO_TRACE_EVENT (4, "resIO");
	CIO_TRACE_EVENT (4, sch->dev.bus_id);

	ccode = rsch (sch->irq);

	sprintf (dbf_txt, "ccode:%d", ccode);
	CIO_TRACE_EVENT (4, dbf_txt);

	switch (ccode) {
	case 0:
		sch->schib.scsw.actl |= SCSW_ACTL_RESUME_PEND;
		return 0;
	case 1:
		return -EBUSY;
	case 2:
		return -EINVAL;
	default:
		/*
		 * useless to wait for request completion
		 *  as device is no longer operational !
		 */
		return -ENODEV;
	}
}

/*
 * halt I/O operation
 */
int
cio_halt(struct subchannel *sch)
{
	char dbf_txt[15];
	int ccode;

	if (!sch)
		return -ENODEV;

	CIO_TRACE_EVENT (2, "haltIO");
	CIO_TRACE_EVENT (2, sch->dev.bus_id);

	/*
	 * Issue "Halt subchannel" and process condition code
	 */
	ccode = hsch (sch->irq);

	sprintf (dbf_txt, "ccode:%d", ccode);
	CIO_TRACE_EVENT (2, dbf_txt);

	switch (ccode) {
	case 0:
		sch->schib.scsw.actl |= SCSW_ACTL_HALT_PEND;
		return 0;
	case 1:		/* status pending */
	case 2:		/* busy */
		return -EBUSY;
	default:		/* device not operational */
		return -ENODEV;
	}
}

/*
 * Clear I/O operation
 */
int
cio_clear(struct subchannel *sch)
{
	char dbf_txt[15];
	int ccode;

	if (!sch)
		return -ENODEV;

	CIO_TRACE_EVENT (2, "clearIO");
	CIO_TRACE_EVENT (2, sch->dev.bus_id);

	/*
	 * Issue "Clear subchannel" and process condition code
	 */
	ccode = csch (sch->irq);

	sprintf (dbf_txt, "ccode:%d", ccode);
	CIO_TRACE_EVENT (2, dbf_txt);

	switch (ccode) {
	case 0:
		sch->schib.scsw.actl |= SCSW_ACTL_CLEAR_PEND;
		return 0;
	default:		/* device not operational */
		return -ENODEV;
	}
}

/*
 * Function: cio_cancel
 * Issues a "Cancel Subchannel" on the specified subchannel
 * Note: We don't need any fancy intparms and flags here
 *	 since xsch is executed synchronously.
 * Only for common I/O internal use as for now.
 */
int
cio_cancel (struct subchannel *sch)
{
	char dbf_txt[15];
	int ccode;

	if (!sch)
		return -ENODEV;

	CIO_TRACE_EVENT (2, "cancelIO");
	CIO_TRACE_EVENT (2, sch->dev.bus_id);

	ccode = xsch (sch->irq);

	sprintf (dbf_txt, "ccode:%d", ccode);
	CIO_TRACE_EVENT (2, dbf_txt);

	switch (ccode) {
	case 0:		/* success */
		/* Update information in scsw. */
		stsch (sch->irq, &sch->schib);
		return 0;
	case 1:		/* status pending */
		return -EBUSY;
	case 2:		/* not applicable */
		return -EINVAL;
	default:	/* not oper */
		return -ENODEV;
	}
}

/*
 * Function: cio_modify
 * Issues a "Modify Subchannel" on the specified subchannel
 */
int
cio_modify (struct subchannel *sch)
{
	int ccode, retry, ret;

	ret = 0;
	for (retry = 0; retry < 5; retry++) {
		ccode = msch_err (sch->irq, &sch->schib);
		if (ccode < 0)	/* -EIO if msch gets a program check. */
			return ccode;
		switch (ccode) {
		case 0: /* successfull */
			return 0;
		case 1:	/* status pending */
			return -EBUSY;
		case 2:	/* busy */
			udelay (100);	/* allow for recovery */
			ret = -EBUSY;
			break;
		case 3:	/* not operational */
			return -ENODEV;
		}
	}
	return ret;
}

/*
 * Enable subchannel.
 */
int
cio_enable_subchannel (struct subchannel *sch, unsigned int isc)
{
	char dbf_txt[15];
	int ccode;
	int retry;
	int ret;

	CIO_TRACE_EVENT (2, "ensch");
	CIO_TRACE_EVENT (2, sch->dev.bus_id);

	ccode = stsch (sch->irq, &sch->schib);
	if (ccode)
		return -ENODEV;

	sch->schib.pmcw.ena = 1;
	sch->schib.pmcw.isc = isc;
	sch->schib.pmcw.intparm = (__u32)(unsigned long)sch;
	for (retry = 5, ret = 0; retry > 0; retry--) {
		ret = cio_modify(sch);
		if (ret == -ENODEV)
			break;
		if (ret == -EIO)
			/*
			 * Got a program check in cio_modify. Try without