Linux-2.6.12-rc2v2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 860 insertions, 0 deletions

diff --git a/drivers/s390/cio/cio.c b/drivers/s390/cio/cio.c
new file mode 100644
index 00000000000..99ce5a56798
--- /dev/null
+++ b/drivers/s390/cio/cio.c
@@ -0,0 +1,860 @@
+/*
+ *  drivers/s390/cio/cio.c
+ *   S/390 common I/O routines -- low level i/o calls
+ *   $Revision: 1.131 $
+ *
+ *    Copyright (C) 1999-2002 IBM Deutschland Entwicklung GmbH,
+ *			      IBM Corporation
+ *    Author(s): Ingo Adlung (adlung@de.ibm.com)
+ *		 Cornelia Huck (cohuck@de.ibm.com)
+ *		 Arnd Bergmann (arndb@de.ibm.com)
+ *		 Martin Schwidefsky (schwidefsky@de.ibm.com)
+ */
+
+#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 <linux/interrupt.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;
+	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->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_key (struct subchannel *sch,	/* subchannel structure */
+	       struct ccw1 * cpa,	/* logical channel prog addr */
+	       __u8 lpm,		/* logical path mask */
+	       __u8 key)                /* storage key */
+{
+	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.key = key >> 4;
+	/* issue "Start Subchannel" */
+	sch->orb.cpa = (__u32) __pa (cpa);
+	ccode = ssch (sch->irq, &sch->orb);
+
+	/* process condition code */
+	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);
+	}
+}
+
+int
+cio_start (struct subchannel *sch, struct ccw1 *cpa, __u8 lpm)
+{
+	return cio_start_key(sch, cpa, lpm, default_storage_key);
+}
+
+/*
+ * 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;
+
+	for (retry = 5, ret = 0; retry > 0; retry--) {
+		sch->schib.pmcw.ena = 1;
+		sch->schib.pmcw.isc = isc;
+		sch->schib.pmcw.intparm = (__u32)(unsigned long)sch;
+		ret = cio_modify(sch);
+		if (ret == -ENODEV)
+			break;
+		if (ret == -EIO)
+			/*
+			 * Got a program check in cio_modify. Try without
+			 * the concurrent sense bit the next time.
+			 */
+			sch->schib.pmcw.csense = 0;
+		if (ret == 0) {
+			stsch (sch->irq, &sch->schib);
+			if (sch->schib.pmcw.ena)
+				break;
+		}
+		if (ret == -EBUSY) {
+			struct irb irb;
+			if (tsch(sch->irq, &irb) != 0)
+				break;
+		}
+	}
+	sprintf (dbf_txt, "ret:%d", ret);
+	CIO_TRACE_EVENT (2, dbf_txt);
+	return ret;
+}
+
+/*
+ * Disable subchannel.
+ */
+int
+cio_disable_subchannel (struct subchannel *sch)
+{
+	char dbf_txt[15];
+	int ccode;
+	int retry;
+	int ret;
+
+	CIO_TRACE_EVENT (2, "dissch");
+	CIO_TRACE_EVENT (2, sch->dev.bus_id);
+
+	ccode = stsch (sch->irq, &sch->schib);
+	if (ccode == 3)		/* Not operational. */
+		return -ENODEV;
+
+	if (sch->schib.scsw.actl != 0)
+		/*
+		 * the disable function must not be called while there are
+		 *  requests pending for completion !
+		 */
+		return -EBUSY;
+
+	for (retry = 5, ret = 0; retry > 0; retry--) {
+		sch->schib.pmcw.ena = 0;
+		ret = cio_modify(sch);
+		if (ret == -ENODEV)
+			break;
+		if (ret == -EBUSY)
+			/*
+			 * The subchannel is busy or status pending.
+			 * We'll disable when the next interrupt was delivered
+			 * via the state machine.
+			 */
+			break;
+		if (ret == 0) {
+			stsch (sch->irq, &sch->schib);
+			if (!sch->schib.pmcw.ena)
+				break;
+		}
+	}
+	sprintf (dbf_txt, "ret:%d", ret);
+	CIO_TRACE_EVENT (2, dbf_txt);
+	return ret;
+}
+
+/*
+ * cio_validate_subchannel()
+ *
+ * Find out subchannel type and initialize struct subchannel.
+ * Return codes:
+ *   SUBCHANNEL_TYPE_IO for a normal io subchannel
+ *   SUBCHANNEL_TYPE_CHSC for a chsc subchannel
+ *   SUBCHANNEL_TYPE_MESSAGE for a messaging subchannel
+ *   SUBCHANNEL_TYPE_ADM for a adm(?) subchannel
+ *   -ENXIO for non-defined subchannels
+ *   -ENODEV for subchannels with invalid device number or blacklisted devices
+ */
+int
+cio_validate_subchannel (struct subchannel *sch, unsigned int irq)
+{
+	char dbf_txt[15];
+	int ccode;
+
+	sprintf (dbf_txt, "valsch%x", irq);
+	CIO_TRACE_EVENT (4, dbf_txt);
+
+	/* Nuke all fields. */
+	memset(sch, 0, sizeof(struct subchannel));
+
+	spin_lock_init(&sch->lock);
+
+	/* Set a name for the subchannel */
+	snprintf (sch->dev.bus_id, BUS_ID_SIZE, "0.0.%04x", irq);
+
+	/*
+	 * The first subchannel that is not-operational (ccode==3)
+	 *  indicates that there aren't any more devices available.
+	 */
+	sch->irq = irq;
+	ccode = stsch (irq, &sch->schib);
+	if (ccode)
+		return -ENXIO;
+
+	/* Copy subchannel type from path management control word. */
+	sch->st = sch->schib.pmcw.st;
+
+	/*
+	 * ... just being curious we check for non I/O subchannels
+	 */
+	if (sch->st != 0) {
+		CIO_DEBUG(KERN_INFO, 0,
+			  "Subchannel %04X reports "
+			  "non-I/O subchannel type %04X\n",
+			  sch->irq, sch->st);
+		/* We stop here for non-io subchannels. */
+		return sch->st;
+	}
+
+	/* Initialization for io subchannels. */
+	if (!sch->schib.pmcw.dnv)
+		/* io subchannel but device number is invalid. */
+		return -ENODEV;
+
+	/* Devno is valid. */
+	if (is_blacklisted (sch->schib.pmcw.dev)) {
+		/*
+		 * This device must not be known to Linux. So we simply
+		 * say that there is no device and return ENODEV.
+		 */
+		CIO_MSG_EVENT(0, "Blacklisted device detected "
+			      "at devno %04X\n", sch->schib.pmcw.dev);
+		return -ENODEV;
+	}
+	sch->opm = 0xff;
+	chsc_validate_chpids(sch);
+	sch->lpm = sch->schib.pmcw.pim &
+		sch->schib.pmcw.pam &
+		sch->schib.pmcw.pom &
+		sch->opm;
+
+	CIO_DEBUG(KERN_INFO, 0,
+		  "Detected device %04X on subchannel %04X"
+		  " - PIM = %02X, PAM = %02X, POM = %02X\n",
+		  sch->schib.pmcw.dev, sch->irq, sch->schib.pmcw.pim,
+		  sch->schib.pmcw.pam, sch->schib.pmcw.pom);
+
+	/*
+	 * We now have to initially ...
+	 *  ... set "interruption subclass"
+	 *  ... enable "concurrent sense"
+	 *  ... enable "multipath mode" if more than one
+	 *	  CHPID is available. This is done regardless
+	 *	  whether multiple paths are available for us.
+	 */
+	sch->schib.pmcw.isc = 3;	/* could be smth. else */
+	sch->schib.pmcw.csense = 1;	/* concurrent sense */
+	sch->schib.pmcw.ena = 0;
+	if ((sch->lpm & (sch->lpm - 1)) != 0)
+		sch->schib.pmcw.mp = 1;	/* multipath mode */
+	return 0;
+}
+
+/*
+ * do_IRQ() handles all normal I/O device IRQ's (the special
+ *	    SMP cross-CPU interrupts have their own specific
+ *	    handlers).
+ *
+ */
+void
+do_IRQ (struct pt_regs *regs)
+{
+	struct tpi_info *tpi_info;
+	struct subchannel *sch;
+	struct irb *irb;
+
+	irq_enter ();
+	asm volatile ("mc 0,0");
+	if (S390_lowcore.int_clock >= S390_lowcore.jiffy_timer)
+		/**
+		 * Make sure that the i/o interrupt did not "overtake"
+		 * the last HZ timer interrupt.
+		 */
+		account_ticks(regs);
+	/*
+	 * Get interrupt information from lowcore
+	 */
+	tpi_info = (struct tpi_info *) __LC_SUBCHANNEL_ID;
+	irb = (struct irb *) __LC_IRB;
+	do {
+		kstat_cpu(smp_processor_id()).irqs[IO_INTERRUPT]++;
+		/*
+		 * Non I/O-subchannel thin interrupts are processed differently
+		 */
+		if (tpi_info->adapter_IO == 1 &&
+		    tpi_info->int_type == IO_INTERRUPT_TYPE) {
+			do_adapter_IO();
+			continue;
+		}
+		sch = (struct subchannel *)(unsigned long)tpi_info->intparm;
+		if (sch)
+			spin_lock(&sch->lock);
+		/* Store interrupt response block to lowcore. */
+		if (tsch (tpi_info->irq, irb) == 0 && sch) {
+			/* Keep subchannel information word up to date. */
+			memcpy (&sch->schib.scsw, &irb->scsw,
+				sizeof (irb->scsw));
+			/* Call interrupt handler if there is one. */
+			if (sch->driver && sch->driver->irq)
+				sch->driver->irq(&sch->dev);
+		}
+		if (sch)
+			spin_unlock(&sch->lock);
+		/*
+		 * Are more interrupts pending?
+		 * If so, the tpi instruction will update the lowcore
+		 * to hold the info for the next interrupt.
+		 * We don't do this for VM because a tpi drops the cpu
+		 * out of the sie which costs more cycles than it saves.
+		 */
+	} while (!MACHINE_IS_VM && tpi (NULL) != 0);
+	irq_exit ();
+}
+
+#ifdef CONFIG_CCW_CONSOLE
+static struct subchannel console_subchannel;
+static int console_subchannel_in_use;
+
+/*
+ * busy wait for the next interrupt on the console
+ */
+void
+wait_cons_dev (void)
+{
+	unsigned long cr6      __attribute__ ((aligned (8)));
+	unsigned long save_cr6 __attribute__ ((aligned (8)));
+
+	/* 
+	 * before entering the spinlock we may already have
+	 * processed the interrupt on a different CPU...
+	 */
+	if (!console_subchannel_in_use)
+		return;
+
+	/* disable all but isc 7 (console device) */
+	__ctl_store (save_cr6, 6, 6);
+	cr6 = 0x01000000;
+	__ctl_load (cr6, 6, 6);
+
+	do {
+		spin_unlock(&console_subchannel.lock);
+		if (!cio_tpi())
+			cpu_relax();
+		spin_lock(&console_subchannel.lock);
+	} while (console_subchannel.schib.scsw.actl != 0);
+	/*
+	 * restore previous isc value
+	 */
+	__ctl_load (save_cr6, 6, 6);
+}
+
+static int
+cio_console_irq(void)
+{
+	int irq;
+	
+	if (console_irq != -1) {
+		/* VM provided us with the irq number of the console. */
+		if (stsch(console_irq, &console_subchannel.schib) != 0 ||
+		    !console_subchannel.schib.pmcw.dnv)
+			return -1;
+		console_devno = console_subchannel.schib.pmcw.dev;
+	} else if (console_devno != -1) {
+		/* At least the console device number is known. */
+		for (irq = 0; irq < __MAX_SUBCHANNELS; irq++) {
+			if (stsch(irq, &console_subchannel.schib) != 0)
+				break;
+			if (console_subchannel.schib.pmcw.dnv &&
+			    console_subchannel.schib.pmcw.dev ==
+			    console_devno) {
+				console_irq = irq;
+				break;
+			}
+		}
+		if (console_irq == -1)
+			return -1;
+	} else {
+		/* unlike in 2.4, we cannot autoprobe here, since
+		 * the channel subsystem is not fully initialized.
+		 * With some luck, the HWC console can take over */
+		printk(KERN_WARNING "No ccw console found!\n");
+		return -1;
+	}
+	return console_irq;
+}
+
+struct subchannel *
+cio_probe_console(void)
+{
+	int irq, ret;
+
+	if (xchg(&console_subchannel_in_use, 1) != 0)
+		return ERR_PTR(-EBUSY);
+	irq = cio_console_irq();
+	if (irq == -1) {
+		console_subchannel_in_use = 0;
+		return ERR_PTR(-ENODEV);
+	}
+	memset(&console_subchannel, 0, sizeof(struct subchannel));
+	ret = cio_validate_subchannel(&console_subchannel, irq);
+	if (ret) {
+		console_subchannel_in_use = 0;
+		return ERR_PTR(-ENODEV);
+	}
+
+	/*
+	 * enable console I/O-interrupt subclass 7
+	 */
+	ctl_set_bit(6, 24);
+	console_subchannel.schib.pmcw.isc = 7;
+	console_subchannel.schib.pmcw.intparm =
+		(__u32)(unsigned long)&console_subchannel;
+	ret = cio_modify(&console_subchannel);
+	if (ret) {
+		console_subchannel_in_use = 0;
+		return ERR_PTR(ret);
+	}
+	return &console_subchannel;
+}
+
+void
+cio_release_console(void)
+{
+	console_subchannel.schib.pmcw.intparm = 0;
+	cio_modify(&console_subchannel);
+	ctl_clear_bit(6, 24);
+	console_subchannel_in_use = 0;
+}
+
+/* Bah... hack to catch console special sausages. */
+int
+cio_is_console(int irq)
+{
+	if (!console_subchannel_in_use)
+		return 0;
+	return (irq == console_subchannel.irq);
+}
+
+struct subchannel *
+cio_get_console_subchannel(void)
+{
+	if (!console_subchannel_in_use)
+		return 0;
+	return &console_subchannel;
+}
+
+#endif
+static inline int
+__disable_subchannel_easy(unsigned int schid, struct schib *schib)
+{
+	int retry, cc;
+
+	cc = 0;
+	for (retry=0;retry<3;retry++) {
+		schib->pmcw.ena = 0;
+		cc = msch(schid, schib);
+		if (cc)
+			return (cc==3?-ENODEV:-EBUSY);
+		stsch(schid, schib);
+		if (!schib->pmcw.ena)
+			return 0;
+	}
+	return -EBUSY; /* uhm... */
+}
+
+static inline int
+__clear_subchannel_easy(unsigned int schid)
+{
+	int retry;
+
+	if (csch(schid))
+		return -ENODEV;
+	for (retry=0;retry<20;retry++) {
+		struct tpi_info ti;
+
+		if (tpi(&ti)) {
+			tsch(schid, (struct irb *)__LC_IRB);
+			return 0;
+		}
+		udelay(100);
+	}
+	return -EBUSY;
+}
+
+extern void do_reipl(unsigned long devno);
+
+/* Clear all subchannels. */
+void
+clear_all_subchannels(void)
+{
+	unsigned int schid;
+
+	local_irq_disable();
+	for (schid=0;schid<=highest_subchannel;schid++) {
+		struct schib schib;
+		if (stsch(schid, &schib))
+			break; /* break out of the loop */
+		if (!schib.pmcw.ena)
+			continue;
+		switch(__disable_subchannel_easy(schid, &schib)) {
+		case 0:
+		case -ENODEV:
+			break;
+		default: /* -EBUSY */
+			if (__clear_subchannel_easy(schid))
+				break; /* give up... jump out of switch */
+			stsch(schid, &schib);
+			__disable_subchannel_easy(schid, &schib);
+		}
+	}
+}
+
+/* Make sure all subchannels are quiet before we re-ipl an lpar. */
+void
+reipl(unsigned long devno)
+{
+	clear_all_subchannels();
+	do_reipl(devno);
+}