[S390] dasd: tunable missing interrupt handler

This feature provides a user interface to specify the timeout for
missing interrupts for standard I/O operations.

Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

6 files changed, 81 insertions, 9 deletions

diff --git a/drivers/s390/block/dasd_devmap.c b/drivers/s390/block/dasd_devmap.c
index bed7b4634ccd..8d41f3ed38d7 100644
--- a/drivers/s390/block/dasd_devmap.c
+++ b/drivers/s390/block/dasd_devmap.c
@@ -1083,6 +1083,49 @@ dasd_eer_store(struct device *dev, struct device_attribute *attr,
 
 static DEVICE_ATTR(eer_enabled, 0644, dasd_eer_show, dasd_eer_store);
 
+/*
+ * expiration time for default requests
+ */
+static ssize_t
+dasd_expires_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+        struct dasd_device *device;
+        int len;
+
+        device = dasd_device_from_cdev(to_ccwdev(dev));
+        if (IS_ERR(device))
+                return -ENODEV;
+        len = snprintf(buf, PAGE_SIZE, "%lu\n", device->default_expires);
+        dasd_put_device(device);
+        return len;
+}
+
+static ssize_t
+dasd_expires_store(struct device *dev, struct device_attribute *attr,
+               const char *buf, size_t count)
+{
+        struct dasd_device *device;
+        unsigned long val;
+
+        device = dasd_device_from_cdev(to_ccwdev(dev));
+        if (IS_ERR(device))
+                return -ENODEV;
+
+        if ((strict_strtoul(buf, 10, &val) != 0) ||
+            (val > DASD_EXPIRES_MAX) || val == 0) {
+                dasd_put_device(device);
+                return -EINVAL;
+        }
+
+        if (val)
+                device->default_expires = val;
+
+        dasd_put_device(device);
+        return count;
+}
+
+static DEVICE_ATTR(expires, 0644, dasd_expires_show, dasd_expires_store);
+
 static struct attribute * dasd_attrs[] = {
         &dev_attr_readonly.attr,
         &dev_attr_discipline.attr,
@@ -1094,6 +1137,7 @@ static struct attribute * dasd_attrs[] = {
         &dev_attr_eer_enabled.attr,
         &dev_attr_erplog.attr,
         &dev_attr_failfast.attr,
+        &dev_attr_expires.attr,
         NULL,
 };
 
diff --git a/drivers/s390/block/dasd_diag.c b/drivers/s390/block/dasd_diag.c
index 687f323cdc38..2b3bc3ec0541 100644
--- a/drivers/s390/block/dasd_diag.c
+++ b/drivers/s390/block/dasd_diag.c
@@ -43,7 +43,7 @@ MODULE_LICENSE("GPL");
                            sizeof(struct dasd_diag_req)) / \
                            sizeof(struct dasd_diag_bio)) / 2)
 #define DIAG_MAX_RETRIES        32
-#define DIAG_TIMEOUT            50 * HZ
+#define DIAG_TIMEOUT            50
 
 static struct dasd_discipline dasd_diag_discipline;
 
@@ -360,6 +360,8 @@ dasd_diag_check_device(struct dasd_device *device)
                 goto out;
         }
 
+        device->default_expires = DIAG_TIMEOUT;
+
         /* Figure out position of label block */
         switch (private->rdc_data.vdev_class) {
         case DEV_CLASS_FBA:
@@ -563,7 +565,7 @@ static struct dasd_ccw_req *dasd_diag_build_cp(struct dasd_device *memdev,
         cqr->startdev = memdev;
         cqr->memdev = memdev;
         cqr->block = block;
-        cqr->expires = DIAG_TIMEOUT;
+        cqr->expires = memdev->default_expires * HZ;
         cqr->status = DASD_CQR_FILLED;
         return cqr;
 }
diff --git a/drivers/s390/block/dasd_eckd.c b/drivers/s390/block/dasd_eckd.c
index 0483b2e76b11..66360c24bd48 100644
--- a/drivers/s390/block/dasd_eckd.c
+++ b/drivers/s390/block/dasd_eckd.c
@@ -1115,8 +1115,9 @@ dasd_eckd_check_characteristics(struct dasd_device *device)
         struct dasd_eckd_private *private;
         struct dasd_block *block;
         struct dasd_uid temp_uid;
-        int is_known, rc;
+        int is_known, rc, i;
         int readonly;
+        unsigned long value;
 
         if (!ccw_device_is_pathgroup(device->cdev)) {
                 dev_warn(&device->cdev->dev,
@@ -1151,6 +1152,18 @@ dasd_eckd_check_characteristics(struct dasd_device *device)
         if (rc)
                 goto out_err1;
 
+        /* set default timeout */
+        device->default_expires = DASD_EXPIRES;
+        if (private->gneq) {
+                value = 1;
+                for (i = 0; i < private->gneq->timeout.value; i++)
+                        value = 10 * value;
+                value = value * private->gneq->timeout.number;
+                /* do not accept useless values */
+                if (value != 0 && value <= DASD_EXPIRES_MAX)
+                        device->default_expires = value;
+        }
+
         /* Generate device unique id */
         rc = dasd_eckd_generate_uid(device);
         if (rc)
@@ -1981,7 +1994,7 @@ static struct dasd_ccw_req *dasd_eckd_build_cp_cmd_single(
         cqr->startdev = startdev;
         cqr->memdev = startdev;
         cqr->block = block;
-        cqr->expires = 5 * 60 * HZ;     /* 5 minutes */
+        cqr->expires = startdev->default_expires * HZ;  /* default 5 minutes */
         cqr->lpm = private->path_data.ppm;
         cqr->retries = 256;
         cqr->buildclk = get_clock();
@@ -2158,7 +2171,7 @@ static struct dasd_ccw_req *dasd_eckd_build_cp_cmd_track(
         cqr->startdev = startdev;
         cqr->memdev = startdev;
         cqr->block = block;
-        cqr->expires = 5 * 60 * HZ;     /* 5 minutes */
+        cqr->expires = startdev->default_expires * HZ;  /* default 5 minutes */
         cqr->lpm = private->path_data.ppm;
         cqr->retries = 256;
         cqr->buildclk = get_clock();
@@ -2406,7 +2419,7 @@ static struct dasd_ccw_req *dasd_eckd_build_cp_tpm_track(
         cqr->startdev = startdev;
         cqr->memdev = startdev;
         cqr->block = block;
-        cqr->expires = 5 * 60 * HZ;     /* 5 minutes */
+        cqr->expires = startdev->default_expires * HZ;  /* default 5 minutes */
         cqr->lpm = private->path_data.ppm;
         cqr->retries = 256;
         cqr->buildclk = get_clock();
diff --git a/drivers/s390/block/dasd_eckd.h b/drivers/s390/block/dasd_eckd.h
index dd6385a5af14..0eb49655a6cd 100644
--- a/drivers/s390/block/dasd_eckd.h
+++ b/drivers/s390/block/dasd_eckd.h
@@ -320,7 +320,12 @@ struct dasd_gneq {
                 __u8 identifier:2;
                 __u8 reserved:6;
         } __attribute__ ((packed)) flags;
-        __u8 reserved[7];
+        __u8 reserved[5];
+        struct {
+                __u8 value:2;
+                __u8 number:6;
+        } __attribute__ ((packed)) timeout;
+        __u8 reserved3;
         __u16 subsystemID;
         __u8 reserved2[22];
 } __attribute__ ((packed));
diff --git a/drivers/s390/block/dasd_fba.c b/drivers/s390/block/dasd_fba.c
index 37282b90eecc..bec5486e0e6d 100644
--- a/drivers/s390/block/dasd_fba.c
+++ b/drivers/s390/block/dasd_fba.c
@@ -163,6 +163,8 @@ dasd_fba_check_characteristics(struct dasd_device *device)
                 return rc;
         }
 
+        device->default_expires = DASD_EXPIRES;
+
         readonly = dasd_device_is_ro(device);
         if (readonly)
                 set_bit(DASD_FLAG_DEVICE_RO, &device->flags);
@@ -370,7 +372,7 @@ static struct dasd_ccw_req *dasd_fba_build_cp(struct dasd_device * memdev,
         cqr->startdev = memdev;
         cqr->memdev = memdev;
         cqr->block = block;
-        cqr->expires = 5 * 60 * HZ;     /* 5 minutes */
+        cqr->expires = memdev->default_expires * HZ;    /* default 5 minutes */
         cqr->retries = 32;
         cqr->buildclk = get_clock();
         cqr->status = DASD_CQR_FILLED;
diff --git a/drivers/s390/block/dasd_int.h b/drivers/s390/block/dasd_int.h
index 49b431d135e0..500678d7116c 100644
--- a/drivers/s390/block/dasd_int.h
+++ b/drivers/s390/block/dasd_int.h
@@ -186,7 +186,7 @@ struct dasd_ccw_req {
 
         /* ... and how */
         unsigned long starttime;        /* jiffies time of request start */
-        int expires;                    /* expiration period in jiffies */
+        unsigned long expires;          /* expiration period in jiffies */
         char lpm;                       /* logical path mask */
         void *data;                     /* pointer to data area */
 
@@ -224,6 +224,9 @@ struct dasd_ccw_req {
 #define DASD_CQR_CLEARED        0x84    /* request was cleared */
 #define DASD_CQR_SUCCESS        0x85    /* request was successful */
 
+/* default expiration time*/
+#define DASD_EXPIRES      300
+#define DASD_EXPIRES_MAX  40000000
 
 /* per dasd_ccw_req flags */
 #define DASD_CQR_FLAGS_USE_ERP   0      /* use ERP for this request */
@@ -404,6 +407,9 @@ struct dasd_device {
 
         /* hook for alias management */
         struct list_head alias_list;
+
+        /* default expiration time in s */
+        unsigned long default_expires;
 };
 
 struct dasd_block {