1 files changed, 1020 insertions, 0 deletions

diff --git a/drivers/s390/cio/cio.c b/drivers/s390/cio/cio.c
new file mode 100644
index 000000000..07fc5d9e7
--- /dev/null
+++ b/drivers/s390/cio/cio.c
@@ -0,0 +1,1020 @@
+/*
+ *   S/390 common I/O routines -- low level i/o calls
+ *
+ *    Copyright IBM Corp. 1999, 2008
+ *    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)
+ */
+
+#define KMSG_COMPONENT "cio"
+#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
+
+#include <linux/ftrace.h>
+#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 <linux/irq.h>
+#include <asm/cio.h>
+#include <asm/delay.h>
+#include <asm/irq.h>
+#include <asm/irq_regs.h>
+#include <asm/setup.h>
+#include <asm/reset.h>
+#include <asm/ipl.h>
+#include <asm/chpid.h>
+#include <asm/airq.h>
+#include <asm/isc.h>
+#include <linux/cputime.h>
+#include <asm/fcx.h>
+#include <asm/nmi.h>
+#include <asm/crw.h>
+#include "cio.h"
+#include "css.h"
+#include "chsc.h"
+#include "ioasm.h"
+#include "io_sch.h"
+#include "blacklist.h"
+#include "cio_debug.h"
+#include "chp.h"
+
+debug_info_t *cio_debug_msg_id;
+debug_info_t *cio_debug_trace_id;
+debug_info_t *cio_debug_crw_id;
+
+DEFINE_PER_CPU_ALIGNED(struct irb, cio_irb);
+EXPORT_PER_CPU_SYMBOL(cio_irb);
+
+/*
+ * Function: cio_debug_init
+ * Initializes three debug logs for common I/O:
+ * - cio_msg logs generic cio messages
+ * - cio_trace logs the calling of different functions
+ * - cio_crw logs machine check related cio messages
+ */
+static int __init cio_debug_init(void)
+{
+	cio_debug_msg_id = debug_register("cio_msg", 16, 1, 11 * 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, 1, 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", 8, 1, 8 * 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, 4);
+	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);
+	return -1;
+}
+
+arch_initcall (cio_debug_init);
+
+int cio_set_options(struct subchannel *sch, int flags)
+{
+	struct io_subchannel_private *priv = to_io_private(sch);
+
+	priv->options.suspend = (flags & DOIO_ALLOW_SUSPEND) != 0;
+	priv->options.prefetch = (flags & DOIO_DENY_PREFETCH) != 0;
+	priv->options.inter = (flags & DOIO_SUPPRESS_INTER) != 0;
+	return 0;
+}
+
+static int
+cio_start_handle_notoper(struct subchannel *sch, __u8 lpm)
+{
+	char dbf_text[15];
+
+	if (lpm != 0)
+		sch->lpm &= ~lpm;
+	else
+		sch->lpm = 0;
+
+	CIO_MSG_EVENT(2, "cio_start: 'not oper' status for "
+		      "subchannel 0.%x.%04x!\n", sch->schid.ssid,
+		      sch->schid.sch_no);
+
+	if (cio_update_schib(sch))
+		return -ENODEV;
+
+	sprintf(dbf_text, "no%s", dev_name(&sch->dev));
+	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 */
+{
+	struct io_subchannel_private *priv = to_io_private(sch);
+	union orb *orb = &priv->orb;
+	int ccode;
+
+	CIO_TRACE_EVENT(5, "stIO");
+	CIO_TRACE_EVENT(5, dev_name(&sch->dev));
+
+	memset(orb, 0, sizeof(union orb));
+	/* sch is always under 2G. */
+	orb->cmd.intparm = (u32)(addr_t)sch;
+	orb->cmd.fmt = 1;
+
+	orb->cmd.pfch = priv->options.prefetch == 0;
+	orb->cmd.spnd = priv->options.suspend;
+	orb->cmd.ssic = priv->options.suspend && priv->options.inter;
+	orb->cmd.lpm = (lpm != 0) ? lpm : sch->lpm;
+	/*
+	 * for 64 bit we always support 64 bit IDAWs with 4k page size only
+	 */
+	orb->cmd.c64 = 1;
+	orb->cmd.i2k = 0;
+	orb->cmd.key = key >> 4;
+	/* issue "Start Subchannel" */
+	orb->cmd.cpa = (__u32) __pa(cpa);
+	ccode = ssch(sch->schid, orb);
+
+	/* process condition code */
+	CIO_HEX_EVENT(5, &ccode, sizeof(ccode));
+
+	switch (ccode) {
+	case 0:
+		/*
+		 * initialize device status information
+		 */
+		sch->schib.scsw.cmd.actl |= SCSW_ACTL_START_PEND;
+		return 0;
+	case 1:		/* status pending */
+	case 2:		/* busy */
+		return -EBUSY;
+	case 3:		/* device/path not operational */
+		return cio_start_handle_notoper(sch, lpm);
+	default:
+		return ccode;
+	}
+}
+
+int
+cio_start (struct subchannel *sch, struct ccw1 *cpa, __u8 lpm)
+{
+	return cio_start_key(sch, cpa, lpm, PAGE_DEFAULT_KEY);
+}
+
+/*
+ * resume suspended I/O operation
+ */
+int
+cio_resume (struct subchannel *sch)
+{
+	int ccode;
+
+	CIO_TRACE_EVENT(4, "resIO");
+	CIO_TRACE_EVENT(4, dev_name(&sch->dev));
+
+	ccode = rsch (sch->schid);
+
+	CIO_HEX_EVENT(4, &ccode, sizeof(ccode));
+
+	switch (ccode) {
+	case 0:
+		sch->schib.scsw.cmd.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)
+{
+	int ccode;
+
+	if (!sch)
+		return -ENODEV;
+
+	CIO_TRACE_EVENT(2, "haltIO");
+	CIO_TRACE_EVENT(2, dev_name(&sch->dev));
+
+	/*
+	 * Issue "Halt subchannel" and process condition code
+	 */
+	ccode = hsch (sch->schid);
+
+	CIO_HEX_EVENT(2, &ccode, sizeof(ccode));
+
+	switch (ccode) {
+	case 0:
+		sch->schib.scsw.cmd.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)
+{
+	int ccode;
+
+	if (!sch)
+		return -ENODEV;
+
+	CIO_TRACE_EVENT(2, "clearIO");
+	CIO_TRACE_EVENT(2, dev_name(&sch->dev));
+
+	/*
+	 * Issue "Clear subchannel" and process condition code
+	 */
+	ccode = csch (sch->schid);
+
+	CIO_HEX_EVENT(2, &ccode, sizeof(ccode));
+
+	switch (ccode) {
+	case 0:
+		sch->schib.scsw.cmd.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)
+{
+	int ccode;
+
+	if (!sch)
+		return -ENODEV;
+
+	CIO_TRACE_EVENT(2, "cancelIO");
+	CIO_TRACE_EVENT(2, dev_name(&sch->dev));
+
+	ccode = xsch (sch->schid);
+
+	CIO_HEX_EVENT(2, &ccode, sizeof(ccode));
+
+	switch (ccode) {
+	case 0:		/* success */
+		/* Update information in scsw. */
+		if (cio_update_schib(sch))
+			return -ENODEV;
+		return 0;
+	case 1:		/* status pending */
+		return -EBUSY;
+	case 2:		/* not applicable */
+		return -EINVAL;
+	default:	/* not oper */
+		return -ENODEV;
+	}
+}
+
+
+static void cio_apply_config(struct subchannel *sch, struct schib *schib)
+{
+	schib->pmcw.intparm = sch->config.intparm;
+	schib->pmcw.mbi = sch->config.mbi;
+	schib->pmcw.isc = sch->config.isc;
+	schib->pmcw.ena = sch->config.ena;
+	schib->pmcw.mme = sch->config.mme;
+	schib->pmcw.mp = sch->config.mp;
+	schib->pmcw.csense = sch->config.csense;
+	schib->pmcw.mbfc = sch->config.mbfc;
+	if (sch->config.mbfc)
+		schib->mba = sch->config.mba;
+}
+
+static int cio_check_config(struct subchannel *sch, struct schib *schib)
+{
+	return (schib->pmcw.intparm == sch->config.intparm) &&
+		(schib->pmcw.mbi == sch->config.mbi) &&
+		(schib->pmcw.isc == sch->config.isc) &&
+		(schib->pmcw.ena == sch->config.ena) &&
+		(schib->pmcw.mme == sch->config.mme) &&
+		(schib->pmcw.mp == sch->config.mp) &&
+		(schib->pmcw.csense == sch->config.csense) &&
+		(schib->pmcw.mbfc == sch->config.mbfc) &&
+		(!sch->config.mbfc || (schib->mba == sch->config.mba));
+}
+
+/*
+ * cio_commit_config - apply configuration to the subchannel
+ */
+int cio_commit_config(struct subchannel *sch)
+{
+	int ccode, retry, ret = 0;
+	struct schib schib;
+	struct irb irb;
+
+	if (stsch_err(sch->schid, &schib) || !css_sch_is_valid(&schib))
+		return -ENODEV;
+
+	for (retry = 0; retry < 5; retry++) {
+		/* copy desired changes to local schib */
+		cio_apply_config(sch, &schib);
+		ccode = msch_err(sch->schid, &schib);
+		if (ccode < 0) /* -EIO if msch gets a program check. */
+			return ccode;
+		switch (ccode) {
+		case 0: /* successful */
+			if (stsch_err(sch->schid, &schib) ||
+			    !css_sch_is_valid(&schib))
+				return -ENODEV;
+			if (cio_check_config(sch, &schib)) {
+				/* commit changes from local schib */
+				memcpy(&sch->schib, &schib, sizeof(schib));
+				return 0;
+			}
+			ret = -EAGAIN;
+			break;
+		case 1: /* status pending */
+			ret = -EBUSY;
+			if (tsch(sch->schid, &irb))
+				return ret;
+			break;
+		case 2: /* busy */
+			udelay(100); /* allow for recovery */
+			ret = -EBUSY;
+			break;
+		case 3: /* not operational */
+			return -ENODEV;
+		}
+	}
+	return ret;
+}
+
+/**
+ * cio_update_schib - Perform stsch and update schib if subchannel is valid.
+ * @sch: subchannel on which to perform stsch
+ * Return zero on success, -ENODEV otherwise.
+ */
+int cio_update_schib(struct subchannel *sch)
+{
+	struct schib schib;
+
+	if (stsch_err(sch->schid, &schib) || !css_sch_is_valid(&schib))
+		return -ENODEV;
+
+	memcpy(&sch->schib, &schib, sizeof(schib));
+	return 0;
+}
+EXPORT_SYMBOL_GPL(cio_update_schib);
+
+/**
+ * cio_enable_subchannel - enable a subchannel.
+ * @sch: subchannel to be enabled
+ * @intparm: interruption parameter to set
+ */
+int cio_enable_subchannel(struct subchannel *sch, u32 intparm)
+{
+	int ret;
+
+	CIO_TRACE_EVENT(2, "ensch");
+	CIO_TRACE_EVENT(2, dev_name(&sch->dev));
+
+	if (sch_is_pseudo_sch(sch))
+		return -EINVAL;
+	if (cio_update_schib(sch))
+		return -ENODEV;
+
+	sch->config.ena = 1;
+	sch->config.isc = sch->isc;
+	sch->config.intparm = intparm;
+
+	ret = cio_commit_config(sch);
+	if (ret == -EIO) {
+		/*
+		 * Got a program check in msch. Try without
+		 * the concurrent sense bit the next time.
+		 */
+		sch->config.csense = 0;
+		ret = cio_commit_config(sch);
+	}
+	CIO_HEX_EVENT(2, &ret, sizeof(ret));
+	return ret;
+}
+EXPORT_SYMBOL_GPL(cio_enable_subchannel);
+
+/**
+ * cio_disable_subchannel - disable a subchannel.
+ * @sch: subchannel to disable
+ */
+int cio_disable_subchannel(struct subchannel *sch)
+{
+	int ret;
+
+	CIO_TRACE_EVENT(2, "dissch");
+	CIO_TRACE_EVENT(2, dev_name(&sch->dev));
+
+	if (sch_is_pseudo_sch(sch))
+		return 0;
+	if (cio_update_schib(sch))
+		return -ENODEV;
+
+	sch->config.ena = 0;
+	ret = cio_commit_config(sch);
+
+	CIO_HEX_EVENT(2, &ret, sizeof(ret));
+	return ret;
+}
+EXPORT_SYMBOL_GPL(cio_disable_subchannel);
+
+static int cio_check_devno_blacklisted(struct subchannel *sch)
+{
+	if (is_blacklisted(sch->schid.ssid, 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(6, "Blacklisted device detected "
+			      "at devno %04X, subchannel set %x\n",
+			      sch->schib.pmcw.dev, sch->schid.ssid);
+		return -ENODEV;
+	}
+	return 0;
+}
+
+static int cio_validate_io_subchannel(struct subchannel *sch)
+{
+	/* Initialization for io subchannels. */
+	if (!css_sch_is_valid(&sch->schib))
+		return -ENODEV;
+
+	/* Devno is valid. */
+	return cio_check_devno_blacklisted(sch);
+}
+
+static int cio_validate_msg_subchannel(struct subchannel *sch)
+{
+	/* Initialization for message subchannels. */
+	if (!css_sch_is_valid(&sch->schib))
+		return -ENODEV;
+
+	/* Devno is valid. */
+	return cio_check_devno_blacklisted(sch);
+}
+
+/**
+ * cio_validate_subchannel - basic validation of subchannel
+ * @sch: subchannel structure to be filled out
+ * @schid: subchannel id
+ *
+ * Find out subchannel type and initialize struct subchannel.
+ * Return codes:
+ *   0 on success
+ *   -ENXIO for non-defined subchannels
+ *   -ENODEV for invalid subchannels or blacklisted devices
+ *   -EIO for subchannels in an invalid subchannel set
+ */
+int cio_validate_subchannel(struct subchannel *sch, struct subchannel_id schid)
+{
+	char dbf_txt[15];
+	int ccode;
+	int err;
+
+	sprintf(dbf_txt, "valsch%x", schid.sch_no);
+	CIO_TRACE_EVENT(4, dbf_txt);
+
+	/*
+	 * The first subchannel that is not-operational (ccode==3)
+	 * indicates that there aren't any more devices available.
+	 * If stsch gets an exception, it means the current subchannel set
+	 * is not valid.
+	 */
+	ccode = stsch_err(schid, &sch->schib);
+	if (ccode) {
+		err = (ccode == 3) ? -ENXIO : ccode;
+		goto out;
+	}
+	sch->st = sch->schib.pmcw.st;
+	sch->schid = schid;
+
+	switch (sch->st) {
+	case SUBCHANNEL_TYPE_IO:
+		err = cio_validate_io_subchannel(sch);
+		break;
+	case SUBCHANNEL_TYPE_MSG:
+		err = cio_validate_msg_subchannel(sch);
+		break;
+	default:
+		err = 0;
+	}
+	if (err)
+		goto out;
+
+	CIO_MSG_EVENT(4, "Subchannel 0.%x.%04x reports subchannel type %04X\n",
+		      sch->schid.ssid, sch->schid.sch_no, sch->st);
+out:
+	return err;
+}
+
+/*
+ * do_cio_interrupt() handles all normal I/O device IRQ's
+ */
+static irqreturn_t do_cio_interrupt(int irq, void *dummy)
+{
+	struct tpi_info *tpi_info;
+	struct subchannel *sch;
+	struct irb *irb;
+
+	set_cpu_flag(CIF_NOHZ_DELAY);
+	tpi_info = (struct tpi_info *) &get_irq_regs()->int_code;
+	irb = this_cpu_ptr(&cio_irb);
+	sch = (struct subchannel *)(unsigned long) tpi_info->intparm;
+	if (!sch) {
+		/* Clear pending interrupt condition. */
+		inc_irq_stat(IRQIO_CIO);
+		tsch(tpi_info->schid, irb);
+		return IRQ_HANDLED;
+	}
+	spin_lock(sch->lock);
+	/* Store interrupt response block to lowcore. */
+	if (tsch(tpi_info->schid, irb) == 0) {
+		/* 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);
+		else
+			inc_irq_stat(IRQIO_CIO);
+	} else
+		inc_irq_stat(IRQIO_CIO);
+	spin_unlock(sch->lock);
+
+	return IRQ_HANDLED;
+}
+
+static struct irqaction io_interrupt = {
+	.name	 = "IO",
+	.handler = do_cio_interrupt,
+};
+
+void __init init_cio_interrupts(void)
+{
+	irq_set_chip_and_handler(IO_INTERRUPT,
+				 &dummy_irq_chip, handle_percpu_irq);
+	setup_irq(IO_INTERRUPT, &io_interrupt);
+}
+
+#ifdef CONFIG_CCW_CONSOLE
+static struct subchannel *console_sch;
+static struct lock_class_key console_sch_key;
+
+/*
+ * Use cio_tsch to update the subchannel status and call the interrupt handler
+ * if status had been pending. Called with the subchannel's lock held.
+ */
+void cio_tsch(struct subchannel *sch)
+{
+	struct irb *irb;
+	int irq_context;
+
+	irb = this_cpu_ptr(&cio_irb);
+	/* Store interrupt response block to lowcore. */
+	if (tsch(sch->schid, irb) != 0)
+		/* Not status pending or not operational. */
+		return;
+	memcpy(&sch->schib.scsw, &irb->scsw, sizeof(union scsw));
+	/* Call interrupt handler with updated status. */
+	irq_context = in_interrupt();
+	if (!irq_context) {
+		local_bh_disable();
+		irq_enter();
+	}
+	kstat_incr_irq_this_cpu(IO_INTERRUPT);
+	if (sch->driver && sch->driver->irq)
+		sch->driver->irq(sch);
+	else
+		inc_irq_stat(IRQIO_CIO);
+	if (!irq_context) {
+		irq_exit();
+		_local_bh_enable();
+	}
+}
+
+static int cio_test_for_console(struct subchannel_id schid, void *data)
+{
+	struct schib schib;
+
+	if (stsch_err(schid, &schib) != 0)
+		return -ENXIO;
+	if ((schib.pmcw.st == SUBCHANNEL_TYPE_IO) && schib.pmcw.dnv &&
+	    (schib.pmcw.dev == console_devno)) {
+		console_irq = schid.sch_no;
+		return 1; /* found */
+	}
+	return 0;
+}
+
+static int cio_get_console_sch_no(void)
+{
+	struct subchannel_id schid;
+	struct schib schib;
+
+	init_subchannel_id(&schid);
+	if (console_irq != -1) {
+		/* VM provided us with the irq number of the console. */
+		schid.sch_no = console_irq;
+		if (stsch_err(schid, &schib) != 0 ||
+		    (schib.pmcw.st != SUBCHANNEL_TYPE_IO) || !schib.pmcw.dnv)
+			return -1;
+		console_devno = schib.pmcw.dev;
+	} else if (console_devno != -1) {
+		/* At least the console device number is known. */
+		for_each_subchannel(cio_test_for_console, NULL);
+	}
+	return console_irq;
+}
+
+struct subchannel *cio_probe_console(void)
+{
+	struct subchannel_id schid;
+	struct subchannel *sch;
+	int sch_no, ret;
+
+	sch_no = cio_get_console_sch_no();
+	if (sch_no == -1) {
+		pr_warning("No CCW console was found\n");
+		return ERR_PTR(-ENODEV);
+	}
+	init_subchannel_id(&schid);
+	schid.sch_no = sch_no;
+	sch = css_alloc_subchannel(schid);
+	if (IS_ERR(sch))
+		return sch;
+
+	lockdep_set_class(sch->lock, &console_sch_key);
+	isc_register(CONSOLE_ISC);
+	sch->config.isc = CONSOLE_ISC;
+	sch->config.intparm = (u32)(addr_t)sch;
+	ret = cio_commit_config(sch);
+	if (ret) {
+		isc_unregister(CONSOLE_ISC);
+		put_device(&sch->dev);
+		return ERR_PTR(ret);
+	}
+	console_sch = sch;
+	return sch;
+}
+
+int cio_is_console(struct subchannel_id schid)
+{
+	if (!console_sch)
+		return 0;
+	return schid_equal(&schid, &console_sch->schid);
+}
+
+void cio_register_early_subchannels(void)
+{
+	int ret;
+
+	if (!console_sch)
+		return;
+
+	ret = css_register_subchannel(console_sch);
+	if (ret)
+		put_device(&console_sch->dev);
+}
+#endif /* CONFIG_CCW_CONSOLE */
+
+static int
+__disable_subchannel_easy(struct subchannel_id schid, struct schib *schib)
+{
+	int retry, cc;
+
+	cc = 0;
+	for (retry=0;retry<3;retry++) {
+		schib->pmcw.ena = 0;
+		cc = msch_err(schid, schib);
+		if (cc)
+			return (cc==3?-ENODEV:-EBUSY);
+		if (stsch_err(schid, schib) || !css_sch_is_valid(schib))
+			return -ENODEV;
+		if (!schib->pmcw.ena)
+			return 0;
+	}
+	return -EBUSY; /* uhm... */
+}
+
+static int
+__clear_io_subchannel_easy(struct subchannel_id schid)
+{
+	int retry;
+
+	if (csch(schid))
+		return -ENODEV;
+	for (retry=0;retry<20;retry++) {
+		struct tpi_info ti;
+
+		if (tpi(&ti)) {
+			tsch(ti.schid, this_cpu_ptr(&cio_irb));
+			if (schid_equal(&ti.schid, &schid))
+				return 0;
+		}
+		udelay_simple(100);
+	}
+	return -EBUSY;
+}
+
+static void __clear_chsc_subchannel_easy(void)
+{
+	/* It seems we can only wait for a bit here :/ */
+	udelay_simple(100);
+}
+
+static int pgm_check_occured;
+
+static void cio_reset_pgm_check_handler(void)
+{
+	pgm_check_occured = 1;
+}
+
+static int stsch_reset(struct subchannel_id schid, struct schib *addr)
+{
+	int rc;
+
+	pgm_check_occured = 0;
+	s390_base_pgm_handler_fn = cio_reset_pgm_check_handler;
+	rc = stsch_err(schid, addr);
+	s390_base_pgm_handler_fn = NULL;
+
+	/* The program check handler could have changed pgm_check_occured. */
+	barrier();
+
+	if (pgm_check_occured)
+		return -EIO;
+	else
+		return rc;
+}
+
+static int __shutdown_subchannel_easy(struct subchannel_id schid, void *data)
+{
+	struct schib schib;
+
+	if (stsch_reset(schid, &schib))
+		return -ENXIO;
+	if (!schib.pmcw.ena)
+		return 0;
+	switch(__disable_subchannel_easy(schid, &schib)) {
+	case 0:
+	case -ENODEV:
+		break;
+	default: /* -EBUSY */
+		switch (schib.pmcw.st) {
+		case SUBCHANNEL_TYPE_IO:
+			if (__clear_io_subchannel_easy(schid))
+				goto out; /* give up... */
+			break;
+		case SUBCHANNEL_TYPE_CHSC:
+			__clear_chsc_subchannel_easy();
+			break;
+		default:
+			/* No default clear strategy */
+			break;
+		}
+		stsch_err(schid, &schib);
+		__disable_subchannel_easy(schid, &schib);
+	}
+out:
+	return 0;
+}
+
+static atomic_t chpid_reset_count;
+
+static void s390_reset_chpids_mcck_handler(void)
+{
+	struct crw crw;
+	struct mci *mci;
+
+	/* Check for pending channel report word. */
+	mci = (struct mci *)&S390_lowcore.mcck_interruption_code;
+	if (!mci->cp)
+		return;
+	/* Process channel report words. */
+	while (stcrw(&crw) == 0) {
+		/* Check for responses to RCHP. */
+		if (crw.slct && crw.rsc == CRW_RSC_CPATH)
+			atomic_dec(&chpid_reset_count);
+	}
+}
+
+#define RCHP_TIMEOUT (30 * USEC_PER_SEC)
+static void css_reset(void)
+{
+	int i, ret;
+	unsigned long long timeout;
+	struct chp_id chpid;
+
+	/* Reset subchannels. */
+	for_each_subchannel(__shutdown_subchannel_easy,  NULL);
+	/* Reset channel paths. */
+	s390_base_mcck_handler_fn = s390_reset_chpids_mcck_handler;
+	/* Enable channel report machine checks. */
+	__ctl_set_bit(14, 28);
+	/* Temporarily reenable machine checks. */
+	local_mcck_enable();
+	chp_id_init(&chpid);
+	for (i = 0; i <= __MAX_CHPID; i++) {
+		chpid.id = i;
+		ret = rchp(chpid);
+		if ((ret == 0) || (ret == 2))
+			/*
+			 * rchp either succeeded, or another rchp is already
+			 * in progress. In either case, we'll get a crw.
+			 */
+			atomic_inc(&chpid_reset_count);
+	}
+	/* Wait for machine check for all channel paths. */
+	timeout = get_tod_clock_fast() + (RCHP_TIMEOUT << 12);
+	while (atomic_read(&chpid_reset_count) != 0) {
+		if (get_tod_clock_fast() > timeout)
+			break;
+		cpu_relax();
+	}
+	/* Disable machine checks again. */
+	local_mcck_disable();
+	/* Disable channel report machine checks. */
+	__ctl_clear_bit(14, 28);
+	s390_base_mcck_handler_fn = NULL;
+}
+
+static struct reset_call css_reset_call = {
+	.fn = css_reset,
+};
+
+static int __init init_css_reset_call(void)
+{
+	atomic_set(&chpid_reset_count, 0);
+	register_reset_call(&css_reset_call);
+	return 0;
+}
+
+arch_initcall(init_css_reset_call);
+
+struct sch_match_id {
+	struct subchannel_id schid;
+	struct ccw_dev_id devid;
+	int rc;
+};
+
+static int __reipl_subchannel_match(struct subchannel_id schid, void *data)
+{
+	struct schib schib;
+	struct sch_match_id *match_id = data;
+
+	if (stsch_reset(schid, &schib))
+		return -ENXIO;
+	if ((schib.pmcw.st == SUBCHANNEL_TYPE_IO) && schib.pmcw.dnv &&
+	    (schib.pmcw.dev == match_id->devid.devno) &&
+	    (schid.ssid == match_id->devid.ssid)) {
+		match_id->schid = schid;
+		match_id->rc = 0;
+		return 1;
+	}
+	return 0;
+}
+
+static int reipl_find_schid(struct ccw_dev_id *devid,
+			    struct subchannel_id *schid)
+{
+	struct sch_match_id match_id;
+
+	match_id.devid = *devid;
+	match_id.rc = -ENODEV;
+	for_each_subchannel(__reipl_subchannel_match, &match_id);
+	if (match_id.rc == 0)
+		*schid = match_id.schid;
+	return match_id.rc;
+}
+
+extern void do_reipl_asm(__u32 schid);
+
+/* Make sure all subchannels are quiet before we re-ipl an lpar. */
+void reipl_ccw_dev(struct ccw_dev_id *devid)
+{
+	struct subchannel_id uninitialized_var(schid);
+
+	s390_reset_system(NULL, NULL, NULL);
+	if (reipl_find_schid(devid, &schid) != 0)
+		panic("IPL Device not found\n");
+	do_reipl_asm(*((__u32*)&schid));
+}
+
+int __init cio_get_iplinfo(struct cio_iplinfo *iplinfo)
+{
+	struct subchannel_id schid;
+	struct schib schib;
+
+	schid = *(struct subchannel_id *)&S390_lowcore.subchannel_id;
+	if (!schid.one)
+		return -ENODEV;
+	if (stsch_err(schid, &schib))
+		return -ENODEV;
+	if (schib.pmcw.st != SUBCHANNEL_TYPE_IO)
+		return -ENODEV;
+	if (!schib.pmcw.dnv)
+		return -ENODEV;
+	iplinfo->devno = schib.pmcw.dev;
+	iplinfo->is_qdio = schib.pmcw.qf;
+	return 0;
+}
+
+/**
+ * cio_tm_start_key - perform start function
+ * @sch: subchannel on which to perform the start function
+ * @tcw: transport-command word to be started
+ * @lpm: mask of paths to use
+ * @key: storage key to use for storage access
+ *
+ * Start the tcw on the given subchannel. Return zero on success, non-zero
+ * otherwise.
+ */
+int cio_tm_start_key(struct subchannel *sch, struct tcw *tcw, u8 lpm, u8 key)
+{
+	int cc;
+	union orb *orb = &to_io_private(sch)->orb;
+
+	memset(orb, 0, sizeof(union orb));
+	orb->tm.intparm = (u32) (addr_t) sch;
+	orb->tm.key = key >> 4;
+	orb->tm.b = 1;
+	orb->tm.lpm = lpm ? lpm : sch->lpm;
+	orb->tm.tcw = (u32) (addr_t) tcw;
+	cc = ssch(sch->schid, orb);
+	switch (cc) {
+	case 0:
+		return 0;
+	case 1:
+	case 2:
+		return -EBUSY;
+	default:
+		return cio_start_handle_notoper(sch, lpm);
+	}
+}
+
+/**
+ * cio_tm_intrg - perform interrogate function
+ * @sch - subchannel on which to perform the interrogate function
+ *
+ * If the specified subchannel is running in transport-mode, perform the
+ * interrogate function. Return zero on success, non-zero otherwie.
+ */
+int cio_tm_intrg(struct subchannel *sch)
+{
+	int cc;
+
+	if (!to_io_private(sch)->orb.tm.b)
+		return -EINVAL;
+	cc = xsch(sch->schid);
+	switch (cc) {
+	case 0:
+	case 2:
+		return 0;
+	case 1:
+		return -EBUSY;
+	default:
+		return -ENODEV;
+	}
+}