1 files changed, 141 insertions, 104 deletions

diff --git a/drivers/s390/cio/cio.c b/drivers/s390/cio/cio.c
index 3db2c386546f..8a8df7552969 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;
         }