1 files changed, 141 insertions, 104 deletions

diff --git a/drivers/s390/cio/cio.c b/drivers/s390/cio/cio.c
index 3db2c386546..8a8df755296 100644
--- a/drivers/s390/cio/cio.c
+++ b/drivers/s390/cio/cio.c
@@ -9,6 +9,9 @@
  *		 Martin Schwidefsky (schwidefsky@de.ibm.com)
  */
 
+#define KMSG_COMPONENT "cio"
+#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
+
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/slab.h>
@@ -104,44 +107,6 @@ cio_get_options (struct subchannel *sch)
        return flags;
 }
 
-/*
- * Use tpi to get a pending interrupt, call the interrupt handler and
- * return a pointer to the subchannel structure.
- */
-static int
-cio_tpi(void)
-{
-	struct tpi_info *tpi_info;
-	struct subchannel *sch;
-	struct irb *irb;
-	int irq_context;
-
-	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;
-	irq_context = in_interrupt();
-	if (!irq_context)
-		local_bh_disable();
-	irq_enter ();
-	spin_lock(sch->lock);
-	memcpy(&sch->schib.scsw, &irb->scsw, sizeof(union scsw));
-	if (sch->driver && sch->driver->irq)
-		sch->driver->irq(sch);
-	spin_unlock(sch->lock);
-	irq_exit ();
-	if (!irq_context)
-		_local_bh_enable();
-	return 1;
-}
-
 static int
 cio_start_handle_notoper(struct subchannel *sch, __u8 lpm)
 {
@@ -152,11 +117,13 @@ cio_start_handle_notoper(struct subchannel *sch, __u8 lpm)
 	else
 		sch->lpm = 0;
 
-	stsch (sch->schid, &sch->schib);
-
 	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));
@@ -354,7 +321,8 @@ cio_cancel (struct subchannel *sch)
 	switch (ccode) {
 	case 0:		/* success */
 		/* Update information in scsw. */
-		stsch (sch->schid, &sch->schib);
+		if (cio_update_schib(sch))
+			return -ENODEV;
 		return 0;
 	case 1:		/* status pending */
 		return -EBUSY;
@@ -365,30 +333,70 @@ cio_cancel (struct subchannel *sch)
 	}
 }
 
+
+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));
+}
+
 /*
- * Function: cio_modify
- * Issues a "Modify Subchannel" on the specified subchannel
+ * cio_commit_config - apply configuration to the subchannel
  */
-int
-cio_modify (struct subchannel *sch)
+int cio_commit_config(struct subchannel *sch)
 {
-	int ccode, retry, ret;
+	struct schib schib;
+	int ccode, retry, ret = 0;
+
+	if (stsch(sch->schid, &schib) || !css_sch_is_valid(&schib))
+		return -ENODEV;
 
-	ret = 0;
 	for (retry = 0; retry < 5; retry++) {
-		ccode = msch_err (sch->schid, &sch->schib);
-		if (ccode < 0)	/* -EIO if msch gets a program check. */
+		/* 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: /* successfull */
-			return 0;
-		case 1:	/* status pending */
+			if (stsch(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 */
 			return -EBUSY;
-		case 2:	/* busy */
-			udelay (100);	/* allow for recovery */
+		case 2: /* busy */
+			udelay(100); /* allow for recovery */
 			ret = -EBUSY;
 			break;
-		case 3:	/* not operational */
+		case 3: /* not operational */
 			return -ENODEV;
 		}
 	}
@@ -396,6 +404,23 @@ cio_modify (struct subchannel *sch)
 }
 
 /**
+ * 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(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
@@ -403,7 +428,6 @@ cio_modify (struct subchannel *sch)
 int cio_enable_subchannel(struct subchannel *sch, u32 intparm)
 {
 	char dbf_txt[15];
-	int ccode;
 	int retry;
 	int ret;
 
@@ -412,33 +436,27 @@ int cio_enable_subchannel(struct subchannel *sch, u32 intparm)
 
 	if (sch_is_pseudo_sch(sch))
 		return -EINVAL;
-	ccode = stsch (sch->schid, &sch->schib);
-	if (ccode)
+	if (cio_update_schib(sch))
 		return -ENODEV;
 
-	for (retry = 5, ret = 0; retry > 0; retry--) {
-		sch->schib.pmcw.ena = 1;
-		sch->schib.pmcw.isc = sch->isc;
-		sch->schib.pmcw.intparm = intparm;
-		ret = cio_modify(sch);
-		if (ret == -ENODEV)
-			break;
-		if (ret == -EIO)
+	sch->config.ena = 1;
+	sch->config.isc = sch->isc;
+	sch->config.intparm = intparm;
+
+	for (retry = 0; retry < 3; retry++) {
+		ret = cio_commit_config(sch);
+		if (ret == -EIO) {
 			/*
-			 * Got a program check in cio_modify. Try without
+			 * Got a program check in msch. Try without
 			 * the concurrent sense bit the next time.
 			 */
-			sch->schib.pmcw.csense = 0;
-		if (ret == 0) {
-			stsch (sch->schid, &sch->schib);
-			if (sch->schib.pmcw.ena)
-				break;
-		}
-		if (ret == -EBUSY) {
+			sch->config.csense = 0;
+		} else if (ret == -EBUSY) {
 			struct irb irb;
 			if (tsch(sch->schid, &irb) != 0)
 				break;
-		}
+		} else
+			break;
 	}
 	sprintf (dbf_txt, "ret:%d", ret);
 	CIO_TRACE_EVENT (2, dbf_txt);
@@ -453,8 +471,6 @@ EXPORT_SYMBOL_GPL(cio_enable_subchannel);
 int cio_disable_subchannel(struct subchannel *sch)
 {
 	char dbf_txt[15];
-	int ccode;
-	int retry;
 	int ret;
 
 	CIO_TRACE_EVENT (2, "dissch");
@@ -462,8 +478,7 @@ int cio_disable_subchannel(struct subchannel *sch)
 
 	if (sch_is_pseudo_sch(sch))
 		return 0;
-	ccode = stsch (sch->schid, &sch->schib);
-	if (ccode == 3)		/* Not operational. */
+	if (cio_update_schib(sch))
 		return -ENODEV;
 
 	if (scsw_actl(&sch->schib.scsw) != 0)
@@ -473,24 +488,9 @@ int cio_disable_subchannel(struct subchannel *sch)
 		 */
 		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->schid, &sch->schib);
-			if (!sch->schib.pmcw.ena)
-				break;
-		}
-	}
+	sch->config.ena = 0;
+	ret = cio_commit_config(sch);
+
 	sprintf (dbf_txt, "ret:%d", ret);
 	CIO_TRACE_EVENT (2, dbf_txt);
 	return ret;
@@ -687,6 +687,43 @@ static char console_sch_name[10] = "0.x.xxxx";
 static struct io_subchannel_private console_priv;
 static int console_subchannel_in_use;
 
+/*
+ * Use tpi to get a pending interrupt, call the interrupt handler and
+ * return a pointer to the subchannel structure.
+ */
+static int cio_tpi(void)
+{
+	struct tpi_info *tpi_info;
+	struct subchannel *sch;
+	struct irb *irb;
+	int irq_context;
+
+	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;
+	irq_context = in_interrupt();
+	if (!irq_context)
+		local_bh_disable();
+	irq_enter();
+	spin_lock(sch->lock);
+	memcpy(&sch->schib.scsw, &irb->scsw, sizeof(union scsw));
+	if (sch->driver && sch->driver->irq)
+		sch->driver->irq(sch);
+	spin_unlock(sch->lock);
+	irq_exit();
+	if (!irq_context)
+		_local_bh_enable();
+	return 1;
+}
+
 void *cio_get_console_priv(void)
 {
 	return &console_priv;
@@ -780,7 +817,7 @@ cio_probe_console(void)
 	sch_no = cio_get_console_sch_no();
 	if (sch_no == -1) {
 		console_subchannel_in_use = 0;
-		printk(KERN_WARNING "cio: No ccw console found!\n");
+		pr_warning("No CCW console was found\n");
 		return ERR_PTR(-ENODEV);
 	}
 	memset(&console_subchannel, 0, sizeof(struct subchannel));
@@ -796,10 +833,9 @@ cio_probe_console(void)
 	 * enable console I/O-interrupt subclass
 	 */
 	isc_register(CONSOLE_ISC);
-	console_subchannel.schib.pmcw.isc = CONSOLE_ISC;
-	console_subchannel.schib.pmcw.intparm =
-		(u32)(addr_t)&console_subchannel;
-	ret = cio_modify(&console_subchannel);
+	console_subchannel.config.isc = CONSOLE_ISC;
+	console_subchannel.config.intparm = (u32)(addr_t)&console_subchannel;
+	ret = cio_commit_config(&console_subchannel);
 	if (ret) {
 		isc_unregister(CONSOLE_ISC);
 		console_subchannel_in_use = 0;
@@ -811,8 +847,8 @@ cio_probe_console(void)
 void
 cio_release_console(void)
 {
-	console_subchannel.schib.pmcw.intparm = 0;
-	cio_modify(&console_subchannel);
+	console_subchannel.config.intparm = 0;
+	cio_commit_config(&console_subchannel);
 	isc_unregister(CONSOLE_ISC);
 	console_subchannel_in_use = 0;
 }
@@ -852,7 +888,8 @@ __disable_subchannel_easy(struct subchannel_id schid, struct schib *schib)
 		cc = msch(schid, schib);
 		if (cc)
 			return (cc==3?-ENODEV:-EBUSY);
-		stsch(schid, schib);
+		if (stsch(schid, schib) || !css_sch_is_valid(schib))
+			return -ENODEV;
 		if (!schib->pmcw.ena)
 			return 0;
 	}