[S390] New DASD feature for ERP related logging

From: Martin Schwidefsky
Date: Fri Dec 08 2006 - 10:21:36 EST


From: Horst Hummel <horst.hummel@xxxxxxxxxx>

[S390] New DASD feature for ERP related logging

It is now possible to enable/disable ERP related logging without re-compile
and re-ipl. A additional sysfs-attribute 'erplog' allows to switch the
logging non-interruptive.

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

drivers/s390/block/dasd.c | 8 +++---
drivers/s390/block/dasd_3990_erp.c | 23 ++++++-----------
drivers/s390/block/dasd_devmap.c | 49 +++++++++++++++++++++++++++++++++++++
drivers/s390/block/dasd_int.h | 4 ---
include/asm-s390/dasd.h | 2 +
5 files changed, 64 insertions(+), 22 deletions(-)

diff -urpN linux-2.6/drivers/s390/block/dasd_3990_erp.c linux-2.6-patched/drivers/s390/block/dasd_3990_erp.c
--- linux-2.6/drivers/s390/block/dasd_3990_erp.c 2006-11-29 22:57:37.000000000 +0100
+++ linux-2.6-patched/drivers/s390/block/dasd_3990_erp.c 2006-12-08 15:52:50.000000000 +0100
@@ -2641,14 +2641,12 @@ dasd_3990_erp_action(struct dasd_ccw_req
struct dasd_ccw_req *erp = NULL;
struct dasd_device *device = cqr->device;
__u32 cpa = cqr->irb.scsw.cpa;
+ struct dasd_ccw_req *temp_erp = NULL;

-#ifdef ERP_DEBUG
- /* print current erp_chain */
- DEV_MESSAGE(KERN_ERR, device, "%s",
- "ERP chain at BEGINNING of ERP-ACTION");
- {
- struct dasd_ccw_req *temp_erp = NULL;
-
+ if (device->features & DASD_FEATURE_ERPLOG) {
+ /* print current erp_chain */
+ DEV_MESSAGE(KERN_ERR, device, "%s",
+ "ERP chain at BEGINNING of ERP-ACTION");
for (temp_erp = cqr;
temp_erp != NULL; temp_erp = temp_erp->refers) {

@@ -2658,7 +2656,6 @@ dasd_3990_erp_action(struct dasd_ccw_req
temp_erp->refers);
}
}
-#endif /* ERP_DEBUG */

/* double-check if current erp/cqr was successfull */
if ((cqr->irb.scsw.cstat == 0x00) &&
@@ -2695,11 +2692,10 @@ dasd_3990_erp_action(struct dasd_ccw_req
erp = dasd_3990_erp_handle_match_erp(cqr, erp);
}

-#ifdef ERP_DEBUG
- /* print current erp_chain */
- DEV_MESSAGE(KERN_ERR, device, "%s", "ERP chain at END of ERP-ACTION");
- {
- struct dasd_ccw_req *temp_erp = NULL;
+ if (device->features & DASD_FEATURE_ERPLOG) {
+ /* print current erp_chain */
+ DEV_MESSAGE(KERN_ERR, device, "%s",
+ "ERP chain at END of ERP-ACTION");
for (temp_erp = erp;
temp_erp != NULL; temp_erp = temp_erp->refers) {

@@ -2709,7 +2705,6 @@ dasd_3990_erp_action(struct dasd_ccw_req
temp_erp->refers);
}
}
-#endif /* ERP_DEBUG */

if (erp->status == DASD_CQR_FAILED)
dasd_log_ccw(erp, 1, cpa);
diff -urpN linux-2.6/drivers/s390/block/dasd.c linux-2.6-patched/drivers/s390/block/dasd.c
--- linux-2.6/drivers/s390/block/dasd.c 2006-12-08 15:52:24.000000000 +0100
+++ linux-2.6-patched/drivers/s390/block/dasd.c 2006-12-08 15:52:50.000000000 +0100
@@ -1050,10 +1050,10 @@ dasd_int_handler(struct ccw_device *cdev
}
} else { /* error */
memcpy(&cqr->irb, irb, sizeof (struct irb));
-#ifdef ERP_DEBUG
- /* dump sense data */
- dasd_log_sense(cqr, irb);
-#endif
+ if (device->features & DASD_FEATURE_ERPLOG) {
+ /* dump sense data */
+ dasd_log_sense(cqr, irb);
+ }
switch (era) {
case dasd_era_fatal:
cqr->status = DASD_CQR_FAILED;
diff -urpN linux-2.6/drivers/s390/block/dasd_devmap.c linux-2.6-patched/drivers/s390/block/dasd_devmap.c
--- linux-2.6/drivers/s390/block/dasd_devmap.c 2006-12-08 15:52:24.000000000 +0100
+++ linux-2.6-patched/drivers/s390/block/dasd_devmap.c 2006-12-08 15:52:50.000000000 +0100
@@ -202,6 +202,8 @@ dasd_feature_list(char *str, char **endp
features |= DASD_FEATURE_READONLY;
else if (len == 4 && !strncmp(str, "diag", 4))
features |= DASD_FEATURE_USEDIAG;
+ else if (len == 6 && !strncmp(str, "erplog", 6))
+ features |= DASD_FEATURE_ERPLOG;
else {
MESSAGE(KERN_WARNING,
"unsupported feature: %*s, "
@@ -709,6 +711,52 @@ dasd_ro_store(struct device *dev, struct
}

static DEVICE_ATTR(readonly, 0644, dasd_ro_show, dasd_ro_store);
+/*
+ * erplog controls the logging of ERP related data
+ * (e.g. failing channel programs).
+ */
+static ssize_t
+dasd_erplog_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+ struct dasd_devmap *devmap;
+ int erplog;
+
+ devmap = dasd_find_busid(dev->bus_id);
+ if (!IS_ERR(devmap))
+ erplog = (devmap->features & DASD_FEATURE_ERPLOG) != 0;
+ else
+ erplog = (DASD_FEATURE_DEFAULT & DASD_FEATURE_ERPLOG) != 0;
+ return snprintf(buf, PAGE_SIZE, erplog ? "1\n" : "0\n");
+}
+
+static ssize_t
+dasd_erplog_store(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct dasd_devmap *devmap;
+ int val;
+ char *endp;
+
+ devmap = dasd_devmap_from_cdev(to_ccwdev(dev));
+ if (IS_ERR(devmap))
+ return PTR_ERR(devmap);
+
+ val = simple_strtoul(buf, &endp, 0);
+ if (((endp + 1) < (buf + count)) || (val > 1))
+ return -EINVAL;
+
+ spin_lock(&dasd_devmap_lock);
+ if (val)
+ devmap->features |= DASD_FEATURE_ERPLOG;
+ else
+ devmap->features &= ~DASD_FEATURE_ERPLOG;
+ if (devmap->device)
+ devmap->device->features = devmap->features;
+ spin_unlock(&dasd_devmap_lock);
+ return count;
+}
+
+static DEVICE_ATTR(erplog, 0644, dasd_erplog_show, dasd_erplog_store);

/*
* use_diag controls whether the driver should use diag rather than ssch
@@ -896,6 +944,7 @@ static struct attribute * dasd_attrs[] =
&dev_attr_uid.attr,
&dev_attr_use_diag.attr,
&dev_attr_eer_enabled.attr,
+ &dev_attr_erplog.attr,
NULL,
};

diff -urpN linux-2.6/drivers/s390/block/dasd_int.h linux-2.6-patched/drivers/s390/block/dasd_int.h
--- linux-2.6/drivers/s390/block/dasd_int.h 2006-12-08 15:52:24.000000000 +0100
+++ linux-2.6-patched/drivers/s390/block/dasd_int.h 2006-12-08 15:52:50.000000000 +0100
@@ -13,10 +13,6 @@

#ifdef __KERNEL__

-/* erp debugging in dasd.c and dasd_3990_erp.c */
-#define ERP_DEBUG
-
-
/* we keep old device allocation scheme; IOW, minors are still in 0..255 */
#define DASD_PER_MAJOR (1U << (MINORBITS - DASD_PARTN_BITS))
#define DASD_PARTN_MASK ((1 << DASD_PARTN_BITS) - 1)
diff -urpN linux-2.6/include/asm-s390/dasd.h linux-2.6-patched/include/asm-s390/dasd.h
--- linux-2.6/include/asm-s390/dasd.h 2006-11-29 22:57:37.000000000 +0100
+++ linux-2.6-patched/include/asm-s390/dasd.h 2006-12-08 15:52:50.000000000 +0100
@@ -69,11 +69,13 @@ typedef struct dasd_information2_t {
* 0x01: readonly (ro)
* 0x02: use diag discipline (diag)
* 0x04: set the device initially online (internal use only)
+ * 0x08: enable ERP related logging
*/
#define DASD_FEATURE_DEFAULT 0x00
#define DASD_FEATURE_READONLY 0x01
#define DASD_FEATURE_USEDIAG 0x02
#define DASD_FEATURE_INITIAL_ONLINE 0x04
+#define DASD_FEATURE_ERPLOG 0x08

#define DASD_PARTN_BITS 2

-
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