[S390] add PAV support to the dasd driver.

Add support for parallel-access-volumes to the dasd driver. This
allows concurrent access to dasd devices with multiple channel
programs.

Signed-off-by: Horst Hummel <horst.hummel@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

7 files changed, 227 insertions, 90 deletions

diff --git a/drivers/s390/block/dasd.c b/drivers/s390/block/dasd.c
index 7e9978ad1445..bafcd2f20ae2 100644
--- a/drivers/s390/block/dasd.c
+++ b/drivers/s390/block/dasd.c
@@ -1855,15 +1855,34 @@ dasd_generic_probe (struct ccw_device *cdev,
 {
         int ret;
 
+        ret = ccw_device_set_options(cdev, CCWDEV_DO_PATHGROUP);
+        if (ret) {
+                printk(KERN_WARNING
+                       "dasd_generic_probe: could not set ccw-device options "
+                       "for %s\n", cdev->dev.bus_id);
+                return ret;
+        }
         ret = dasd_add_sysfs_files(cdev);
         if (ret) {
                 printk(KERN_WARNING
                        "dasd_generic_probe: could not add sysfs entries "
                        "for %s\n", cdev->dev.bus_id);
-        } else {
-                cdev->handler = &dasd_int_handler;
+                return ret;
         }
+        cdev->handler = &dasd_int_handler;
 
+        /*
+         * Automatically online either all dasd devices (dasd_autodetect)
+         * or all devices specified with dasd= parameters during
+         * initial probe.
+         */
+        if ((dasd_get_feature(cdev, DASD_FEATURE_INITIAL_ONLINE) > 0 ) ||
+            (dasd_autodetect && dasd_busid_known(cdev->dev.bus_id) != 0))
+                ret = ccw_device_set_online(cdev);
+        if (ret)
+                printk(KERN_WARNING
+                       "dasd_generic_probe: could not initially online "
+                       "ccw-device %s\n", cdev->dev.bus_id);
         return ret;
 }
 
@@ -1911,6 +1930,8 @@ dasd_generic_set_online (struct ccw_device *cdev,
         struct dasd_device *device;
         int rc;
 
+        /* first online clears initial online feature flag */
+        dasd_set_feature(cdev, DASD_FEATURE_INITIAL_ONLINE, 0);
         device = dasd_create_device(cdev);
         if (IS_ERR(device))
                 return PTR_ERR(device);
@@ -2065,31 +2086,6 @@ dasd_generic_notify(struct ccw_device *cdev, int event)
         return ret;
 }
 
-/*
- * Automatically online either all dasd devices (dasd_autodetect) or
- * all devices specified with dasd= parameters.
- */
-static int
-__dasd_auto_online(struct device *dev, void *data)
-{
-        struct ccw_device *cdev;
-
-        cdev = to_ccwdev(dev);
-        if (dasd_autodetect || dasd_busid_known(cdev->dev.bus_id) == 0)
-                ccw_device_set_online(cdev);
-        return 0;
-}
-
-void
-dasd_generic_auto_online (struct ccw_driver *dasd_discipline_driver)
-{
-        struct device_driver *drv;
-
-        drv = get_driver(&dasd_discipline_driver->driver);
-        driver_for_each_device(drv, NULL, NULL, __dasd_auto_online);
-        put_driver(drv);
-}
-
 
 static int __init
 dasd_init(void)
@@ -2170,5 +2166,4 @@ EXPORT_SYMBOL_GPL(dasd_generic_remove);
 EXPORT_SYMBOL_GPL(dasd_generic_notify);
 EXPORT_SYMBOL_GPL(dasd_generic_set_online);
 EXPORT_SYMBOL_GPL(dasd_generic_set_offline);
-EXPORT_SYMBOL_GPL(dasd_generic_auto_online);
 
diff --git a/drivers/s390/block/dasd_devmap.c b/drivers/s390/block/dasd_devmap.c
index 672e50314b12..9e9ae7179602 100644
--- a/drivers/s390/block/dasd_devmap.c
+++ b/drivers/s390/block/dasd_devmap.c
@@ -27,7 +27,7 @@
 #include "dasd_int.h"
 
 kmem_cache_t *dasd_page_cache;
-EXPORT_SYMBOL(dasd_page_cache);
+EXPORT_SYMBOL_GPL(dasd_page_cache);
 
 /*
  * dasd_devmap_t is used to store the features and the relation
@@ -49,6 +49,20 @@ struct dasd_devmap {
 };
 
 /*
+ * dasd_servermap is used to store the server_id of all storage servers
+ * accessed by DASD device driver.
+ */
+struct dasd_servermap {
+        struct list_head list;
+        struct server_id {
+                char vendor[4];
+                char serial[15];
+        } sid;
+};
+
+static struct list_head dasd_serverlist;
+
+/*
  * Parameter parsing functions for dasd= parameter. The syntax is:
  *   <devno>            : (0x)?[0-9a-fA-F]+
  *   <busid>            : [0-0a-f]\.[0-9a-f]\.(0x)?[0-9a-fA-F]+
@@ -64,6 +78,8 @@ struct dasd_devmap {
 
 int dasd_probeonly =  0;        /* is true, when probeonly mode is active */
 int dasd_autodetect = 0;        /* is true, when autodetection is active */
+int dasd_nopav = 0;             /* is true, when PAV is disabled */
+EXPORT_SYMBOL_GPL(dasd_nopav);
 
 /*
  * char *dasd[] is intended to hold the ranges supplied by the dasd= statement
@@ -228,19 +244,24 @@ dasd_parse_keyword( char *parsestring ) {
                 length = strlen(parsestring);
                 residual_str = parsestring + length;
         }
-        if (strncmp ("autodetect", parsestring, length) == 0) {
+        if (strncmp("autodetect", parsestring, length) == 0) {
                 dasd_autodetect = 1;
                 MESSAGE (KERN_INFO, "%s",
                          "turning to autodetection mode");
                 return residual_str;
         }
-        if (strncmp ("probeonly", parsestring, length) == 0) {
+        if (strncmp("probeonly", parsestring, length) == 0) {
                 dasd_probeonly = 1;
                 MESSAGE(KERN_INFO, "%s",
                         "turning to probeonly mode");
                 return residual_str;
         }
-        if (strncmp ("fixedbuffers", parsestring, length) == 0) {
+        if (strncmp("nopav", parsestring, length) == 0) {
+                dasd_nopav = 1;
+                MESSAGE(KERN_INFO, "%s", "disable PAV mode");
+                return residual_str;
+        }
+        if (strncmp("fixedbuffers", parsestring, length) == 0) {
                 if (dasd_page_cache)
                         return residual_str;
                 dasd_page_cache =
@@ -294,6 +315,8 @@ dasd_parse_range( char *parsestring ) {
         features = dasd_feature_list(str, &str);
         if (features < 0)
                 return ERR_PTR(-EINVAL);
+        /* each device in dasd= parameter should be set initially online */
+        features |= DASD_FEATURE_INITIAL_ONLINE;
         while (from <= to) {
                 sprintf(bus_id, "%01x.%01x.%04x",
                         from_id0, from_id1, from++);
@@ -836,6 +859,38 @@ static struct attribute_group dasd_attr_group = {
         .attrs = dasd_attrs,
 };
 
+/*
+ * Check if the related storage server is already contained in the
+ * dasd_serverlist. If server is not contained, create new entry.
+ * Return 0 if server was already in serverlist,
+ *        1 if the server was added successfully
+ *       <0 in case of error.
+ */
+static int
+dasd_add_server(struct dasd_uid *uid)
+{
+        struct dasd_servermap *new, *tmp;
+
+        /* check if server is already contained */
+        list_for_each_entry(tmp, &dasd_serverlist, list)
+          // normale cmp?
+                if (strncmp(tmp->sid.vendor, uid->vendor,
+                            sizeof(tmp->sid.vendor)) == 0
+                    && strncmp(tmp->sid.serial, uid->serial,
+                               sizeof(tmp->sid.serial)) == 0)
+                        return 0;
+
+        new = (struct dasd_servermap *)
+                kzalloc(sizeof(struct dasd_servermap), GFP_KERNEL);
+        if (!new)
+                return -ENOMEM;
+
+        strncpy(new->sid.vendor, uid->vendor, sizeof(new->sid.vendor));
+        strncpy(new->sid.serial, uid->serial, sizeof(new->sid.serial));
+        list_add(&new->list, &dasd_serverlist);
+        return 1;
+}
+
 
 /*
  * Return copy of the device unique identifier.
@@ -856,21 +911,26 @@ dasd_get_uid(struct ccw_device *cdev, struct dasd_uid *uid)
 
 /*
  * Register the given device unique identifier into devmap struct.
+ * Return 0 if server was already in serverlist,
+ *        1 if the server was added successful
+ *       <0 in case of error.
  */
 int
 dasd_set_uid(struct ccw_device *cdev, struct dasd_uid *uid)
 {
         struct dasd_devmap *devmap;
+        int rc;
 
         devmap = dasd_find_busid(cdev->dev.bus_id);
         if (IS_ERR(devmap))
                 return PTR_ERR(devmap);
         spin_lock(&dasd_devmap_lock);
         devmap->uid = *uid;
+        rc = dasd_add_server(uid);
         spin_unlock(&dasd_devmap_lock);
-        return 0;
+        return rc;
 }
-EXPORT_SYMBOL(dasd_set_uid);
+EXPORT_SYMBOL_GPL(dasd_set_uid);
 
 /*
  * Return value of the specified feature.
@@ -882,7 +942,7 @@ dasd_get_feature(struct ccw_device *cdev, int feature)
 
         devmap = dasd_find_busid(cdev->dev.bus_id);
         if (IS_ERR(devmap))
-                return (int) PTR_ERR(devmap);
+                return PTR_ERR(devmap);
 
         return ((devmap->features & feature) != 0);
 }
@@ -898,7 +958,7 @@ dasd_set_feature(struct ccw_device *cdev, int feature, int flag)
 
         devmap = dasd_find_busid(cdev->dev.bus_id);
         if (IS_ERR(devmap))
-                return (int) PTR_ERR(devmap);
+                return PTR_ERR(devmap);
 
         spin_lock(&dasd_devmap_lock);
         if (flag)
@@ -934,8 +994,10 @@ dasd_devmap_init(void)
         dasd_max_devindex = 0;
         for (i = 0; i < 256; i++)
                 INIT_LIST_HEAD(&dasd_hashlists[i]);
-        return 0;
 
+        /* Initialize servermap structure. */
+        INIT_LIST_HEAD(&dasd_serverlist);
+        return 0;
 }
 
 void
diff --git a/drivers/s390/block/dasd_eckd.c b/drivers/s390/block/dasd_eckd.c
index 12257776e79b..0dfab30e8089 100644
--- a/drivers/s390/block/dasd_eckd.c
+++ b/drivers/s390/block/dasd_eckd.c
@@ -24,6 +24,7 @@
 #include <asm/io.h>
 #include <asm/todclk.h>
 #include <asm/uaccess.h>
+#include <asm/cio.h>
 #include <asm/ccwdev.h>
 
 #include "dasd_int.h"
@@ -89,17 +90,22 @@ dasd_eckd_probe (struct ccw_device *cdev)
 {
         int ret;
 
-        ret = dasd_generic_probe (cdev, &dasd_eckd_discipline);
-        if (ret)
+        /* set ECKD specific ccw-device options */
+        ret = ccw_device_set_options(cdev, CCWDEV_ALLOW_FORCE);
+        if (ret) {
+                printk(KERN_WARNING
+                       "dasd_eckd_probe: could not set ccw-device options "
+                       "for %s\n", cdev->dev.bus_id);
                 return ret;
-        ccw_device_set_options(cdev, CCWDEV_DO_PATHGROUP | CCWDEV_ALLOW_FORCE);
-        return 0;
+        }
+        ret = dasd_generic_probe(cdev, &dasd_eckd_discipline);
+        return ret;
 }
 
 static int
 dasd_eckd_set_online(struct ccw_device *cdev)
 {
-        return dasd_generic_set_online (cdev, &dasd_eckd_discipline);
+        return dasd_generic_set_online(cdev, &dasd_eckd_discipline);
 }
 
 static struct ccw_driver dasd_eckd_driver = {
@@ -541,6 +547,86 @@ dasd_eckd_read_conf(struct dasd_device *device)
 }
 
 /*
+ * Build CP for Perform Subsystem Function - SSC.
+ */
+struct dasd_ccw_req *
+dasd_eckd_build_psf_ssc(struct dasd_device *device)
+{
+       struct dasd_ccw_req *cqr;
+       struct dasd_psf_ssc_data *psf_ssc_data;
+       struct ccw1 *ccw;
+
+       cqr = dasd_smalloc_request("ECKD", 1 /* PSF */ ,
+                                  sizeof(struct dasd_psf_ssc_data),
+                                  device);
+
+       if (IS_ERR(cqr)) {
+               DEV_MESSAGE(KERN_WARNING, device, "%s",
+                           "Could not allocate PSF-SSC request");
+               return cqr;
+       }
+       psf_ssc_data = (struct dasd_psf_ssc_data *)cqr->data;
+       psf_ssc_data->order = PSF_ORDER_SSC;
+       psf_ssc_data->suborder = 0x08;
+
+       ccw = cqr->cpaddr;
+       ccw->cmd_code = DASD_ECKD_CCW_PSF;
+       ccw->cda = (__u32)(addr_t)psf_ssc_data;
+       ccw->count = 66;
+
+       cqr->device = device;
+       cqr->expires = 10*HZ;
+       cqr->buildclk = get_clock();
+       cqr->status = DASD_CQR_FILLED;
+       return cqr;
+}
+
+/*
+ * Perform Subsystem Function.
+ * It is necessary to trigger CIO for channel revalidation since this
+ * call might change behaviour of DASD devices.
+ */
+static int
+dasd_eckd_psf_ssc(struct dasd_device *device)
+{
+       struct dasd_ccw_req *cqr;
+       int rc;
+
+       cqr = dasd_eckd_build_psf_ssc(device);
+       if (IS_ERR(cqr))
+               return PTR_ERR(cqr);
+
+       rc = dasd_sleep_on(cqr);
+       if (!rc)
+               /* trigger CIO to reprobe devices */
+               css_schedule_reprobe();
+       dasd_sfree_request(cqr, cqr->device);
+       return rc;
+}
+
+/*
+ * Valide storage server of current device.
+ */
+static int
+dasd_eckd_validate_server(struct dasd_device *device)
+{
+        int rc;
+
+        /* Currently PAV is the only reason to 'validate' server on LPAR */
+        if (dasd_nopav || MACHINE_IS_VM)
+                return 0;
+
+        rc = dasd_eckd_psf_ssc(device);
+        if (rc)
+                /* may be requested feature is not available on server,
+                 * therefore just report error and go ahead */
+                DEV_MESSAGE(KERN_INFO, device,
+                            "Perform Subsystem Function returned rc=%d", rc);
+        /* RE-Read Configuration Data */
+        return dasd_eckd_read_conf(device);
+}
+
+/*
  * Check device characteristics.
  * If the device is accessible using ECKD discipline, the device is enabled.
  */
@@ -570,16 +656,29 @@ dasd_eckd_check_characteristics(struct dasd_device *device)
         private->attrib.operation = DASD_NORMAL_CACHE;
         private->attrib.nr_cyl = 0;
 
+        /* Read Configuration Data */
+        rc = dasd_eckd_read_conf(device);
+        if (rc)
+                return rc;
+
+        /* Generate device unique id and register in devmap */
+        rc = dasd_eckd_generate_uid(device, &uid);
+        if (rc)
+                return rc;
+        rc = dasd_set_uid(device->cdev, &uid);
+        if (rc == 1)    /* new server found */
+                rc = dasd_eckd_validate_server(device);
+        if (rc)
+                return rc;
+
         /* Read Device Characteristics */
         rdc_data = (void *) &(private->rdc_data);
         memset(rdc_data, 0, sizeof(rdc_data));
         rc = read_dev_chars(device->cdev, &rdc_data, 64);
-        if (rc) {
+        if (rc)
                 DEV_MESSAGE(KERN_WARNING, device,
-                            "Read device characteristics returned error %d",
-                            rc);
-                return rc;
-        }
+                            "Read device characteristics returned "
+                            "rc=%d", rc);
 
         DEV_MESSAGE(KERN_INFO, device,
                     "%04X/%02X(CU:%04X/%02X) Cyl:%d Head:%d Sec:%d",
@@ -590,19 +689,6 @@ dasd_eckd_check_characteristics(struct dasd_device *device)
                     private->rdc_data.no_cyl,
                     private->rdc_data.trk_per_cyl,
                     private->rdc_data.sec_per_trk);
-
-        /* Read Configuration Data */
-        rc = dasd_eckd_read_conf (device);
-        if (rc)
-                return rc;
-
-        /* Generate device unique id and register in devmap */
-        rc = dasd_eckd_generate_uid(device, &uid);
-        if (rc)
-                return rc;
-
-        rc = dasd_set_uid(device->cdev, &uid);
-
         return rc;
 }
 
@@ -1687,14 +1773,8 @@ static struct dasd_discipline dasd_eckd_discipline = {
 static int __init
 dasd_eckd_init(void)
 {
-        int ret;
-
         ASCEBC(dasd_eckd_discipline.ebcname, 4);
-
-        ret = ccw_driver_register(&dasd_eckd_driver);
-        if (!ret)
-                dasd_generic_auto_online(&dasd_eckd_driver);
-        return ret;
+        return ccw_driver_register(&dasd_eckd_driver);
 }
 
 static void __exit
diff --git a/drivers/s390/block/dasd_eckd.h b/drivers/s390/block/dasd_eckd.h
index 9d91c8632569..712ff1650134 100644
--- a/drivers/s390/block/dasd_eckd.h
+++ b/drivers/s390/block/dasd_eckd.h
@@ -41,9 +41,10 @@
 #define DASD_ECKD_CCW_RESERVE            0xB4
 
 /*
- *Perform Subsystem Function / Sub-Orders
+ * Perform Subsystem Function / Sub-Orders
  */
-#define PSF_ORDER_PRSSD                  0x18
+#define PSF_ORDER_PRSSD 0x18
+#define PSF_ORDER_SSC   0x1D
 
 /*****************************************************************************
  * SECTION: Type Definitions
@@ -353,4 +354,15 @@ struct dasd_psf_prssd_data {
         unsigned char varies[9];
 } __attribute__ ((packed));
 
+/*
+ * Perform Subsystem Function - Set Subsystem Characteristics
+ */
+struct dasd_psf_ssc_data {
+        unsigned char order;
+        unsigned char flags;
+        unsigned char cu_type[4];
+        unsigned char suborder;
+        unsigned char reserved[59];
+} __attribute__((packed));
+
 #endif                          /* DASD_ECKD_H */
diff --git a/drivers/s390/block/dasd_fba.c b/drivers/s390/block/dasd_fba.c
index d331c6e22c59..bb7755b9b19d 100644
--- a/drivers/s390/block/dasd_fba.c
+++ b/drivers/s390/block/dasd_fba.c
@@ -56,19 +56,13 @@ static struct ccw_driver dasd_fba_driver; /* see below */
 static int
 dasd_fba_probe(struct ccw_device *cdev)
 {
-        int ret;
-
-        ret = dasd_generic_probe (cdev, &dasd_fba_discipline);
-        if (ret)
-                return ret;
-        ccw_device_set_options(cdev, CCWDEV_DO_PATHGROUP);
-        return 0;
+        return dasd_generic_probe(cdev, &dasd_fba_discipline);
 }
 
 static int
 dasd_fba_set_online(struct ccw_device *cdev)
 {
-        return dasd_generic_set_online (cdev, &dasd_fba_discipline);
+        return dasd_generic_set_online(cdev, &dasd_fba_discipline);
 }
 
 static struct ccw_driver dasd_fba_driver = {
@@ -569,16 +563,8 @@ static struct dasd_discipline dasd_fba_discipline = {
 static int __init
 dasd_fba_init(void)
 {
-        int ret;
-
         ASCEBC(dasd_fba_discipline.ebcname, 4);
-
-        ret = ccw_driver_register(&dasd_fba_driver);
-        if (ret)
-                return ret;
-
-        dasd_generic_auto_online(&dasd_fba_driver);
-        return 0;
+        return ccw_driver_register(&dasd_fba_driver);
 }
 
 static void __exit
diff --git a/drivers/s390/block/dasd_int.h b/drivers/s390/block/dasd_int.h
index 2c1fa85a3dad..03a83efc34c4 100644
--- a/drivers/s390/block/dasd_int.h
+++ b/drivers/s390/block/dasd_int.h
@@ -513,12 +513,12 @@ void dasd_generic_remove (struct ccw_device *cdev);
 int dasd_generic_set_online(struct ccw_device *, struct dasd_discipline *);
 int dasd_generic_set_offline (struct ccw_device *cdev);
 int dasd_generic_notify(struct ccw_device *, int);
-void dasd_generic_auto_online (struct ccw_driver *);
 
 /* externals in dasd_devmap.c */
 extern int dasd_max_devindex;
 extern int dasd_probeonly;
 extern int dasd_autodetect;
+extern int dasd_nopav;
 
 int dasd_devmap_init(void);
 void dasd_devmap_exit(void);
diff --git a/include/asm-s390/dasd.h b/include/asm-s390/dasd.h
index 1630c26e8f45..c042f9578081 100644
--- a/include/asm-s390/dasd.h
+++ b/include/asm-s390/dasd.h
@@ -68,10 +68,12 @@ typedef struct dasd_information2_t {
  * 0x00: default features
  * 0x01: readonly (ro)
  * 0x02: use diag discipline (diag)
+ * 0x04: set the device initially online (internal use only)
  */
-#define DASD_FEATURE_DEFAULT  0
-#define DASD_FEATURE_READONLY 1
-#define DASD_FEATURE_USEDIAG  2
+#define DASD_FEATURE_DEFAULT         0x00
+#define DASD_FEATURE_READONLY        0x01
+#define DASD_FEATURE_USEDIAG         0x02
+#define DASD_FEATURE_INITIAL_ONLINE  0x04
 
 #define DASD_PARTN_BITS 2