Add a function to check if a device is accessible.
This makes mostly sense for copy pair secondary devices but it will work
for all devices.
The sysfs attribute ping is a write only attribute and will issue a NOP
CCW to the device.
In case of success it will return zero. If the device is not accessible
it will return an error code.
Signed-off-by: Stefan Haberland <sth@xxxxxxxxxxxxx>
Reviewed-by: Jan Hoeppner <hoeppner@xxxxxxxxxxxxx>
---
drivers/s390/block/dasd_devmap.c | 35 +++++++++++++++++++++++++
drivers/s390/block/dasd_eckd.c | 44 ++++++++++++++++++++++++++++++++
drivers/s390/block/dasd_eckd.h | 1 +
drivers/s390/block/dasd_int.h | 1 +
4 files changed, 81 insertions(+)
diff --git a/drivers/s390/block/dasd_devmap.c b/drivers/s390/block/dasd_devmap.c
index ca5c9e963662..2f7341412ea9 100644
--- a/drivers/s390/block/dasd_devmap.c
+++ b/drivers/s390/block/dasd_devmap.c
@@ -2234,6 +2234,40 @@ dasd_copy_role_show(struct device *dev,
}
static DEVICE_ATTR(copy_role, 0444, dasd_copy_role_show, NULL);
+static ssize_t dasd_device_ping(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct dasd_device *device;
+ size_t rc;
+
+ device = dasd_device_from_cdev(to_ccwdev(dev));
+ if (IS_ERR(device))
+ return -ENODEV;
+
+ /*
+ * do not try during offline processing
+ * early check only
+ * the sleep_on function itself checks for offline
+ * processing again
+ */
+ if (test_bit(DASD_FLAG_OFFLINE, &device->flags)) {
+ rc = -EBUSY;
+ goto out;
+ }
+ if (!device->discipline || !device->discipline->device_ping) {
+ rc = -EOPNOTSUPP;
+ goto out;
+ }
+ rc = device->discipline->device_ping(device);
+ if (!rc)
+ rc = count;
+out:
+ dasd_put_device(device);
+ return rc;
+}
+static DEVICE_ATTR(ping, 0200, NULL, dasd_device_ping);
+
#define DASD_DEFINE_ATTR(_name, _func) \
static ssize_t dasd_##_name##_show(struct device *dev, \
struct device_attribute *attr, \
@@ -2292,6 +2326,7 @@ static struct attribute * dasd_attrs[] = {
&dev_attr_fc_security.attr,
&dev_attr_copy_pair.attr,
&dev_attr_copy_role.attr,
+ &dev_attr_ping.attr,
NULL,
};
diff --git a/drivers/s390/block/dasd_eckd.c b/drivers/s390/block/dasd_eckd.c
index d4d3bd33553b..95b0cd071cad 100644
--- a/drivers/s390/block/dasd_eckd.c
+++ b/drivers/s390/block/dasd_eckd.c
@@ -6277,6 +6277,49 @@ static int dasd_eckd_query_pprc_status(struct dasd_device *device,
return rc;
}
+/*
+ * ECKD NOP - no operation
+ */
+static int dasd_eckd_nop(struct dasd_device *device)
+{
+ struct dasd_ccw_req *cqr;
+ struct ccw1 *ccw;
+ int rc;
+
+ cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, 1, 1, device, NULL);
+ if (IS_ERR(cqr)) {
+ DBF_EVENT_DEVID(DBF_WARNING, device->cdev, "%s",
+ "Could not allocate NOP request");
+ return PTR_ERR(cqr);
+ }
+ cqr->startdev = device;
+ cqr->memdev = device;
+ cqr->block = NULL;
+ cqr->retries = 1;
+ cqr->expires = 10 * HZ;
+
+ ccw = cqr->cpaddr;
+ ccw->cmd_code = DASD_ECKD_CCW_NOP;
+ ccw->flags |= CCW_FLAG_SLI;
+
+ cqr->buildclk = get_tod_clock();
+ cqr->status = DASD_CQR_FILLED;
+
+ rc = dasd_sleep_on_interruptible(cqr);
+ if (rc != 0) {
+ DBF_EVENT_DEVID(DBF_WARNING, device->cdev,
+ "NOP failed with rc=%d\n", rc);
+ rc = -EOPNOTSUPP;
+ }
+ dasd_sfree_request(cqr, cqr->memdev);
+ return rc;
+}
+
+static int dasd_eckd_device_ping(struct dasd_device *device)
+{
+ return dasd_eckd_nop(device);
+}
+
/*
* Perform Subsystem Function - CUIR response
*/
@@ -6899,6 +6942,7 @@ static struct dasd_discipline dasd_eckd_discipline = {
.pprc_status = dasd_eckd_query_pprc_status,
.pprc_enabled = dasd_eckd_pprc_enabled,
.copy_pair_swap = dasd_eckd_copy_pair_swap,
+ .device_ping = dasd_eckd_device_ping,
};
static int __init
diff --git a/drivers/s390/block/dasd_eckd.h b/drivers/s390/block/dasd_eckd.h
index 4da9d0331be5..f9299bd184ba 100644
--- a/drivers/s390/block/dasd_eckd.h
+++ b/drivers/s390/block/dasd_eckd.h
@@ -13,6 +13,7 @@
/*****************************************************************************
* SECTION: CCW Definitions
****************************************************************************/
+#define DASD_ECKD_CCW_NOP 0x03
#define DASD_ECKD_CCW_WRITE 0x05
#define DASD_ECKD_CCW_READ 0x06
#define DASD_ECKD_CCW_WRITE_HOME_ADDRESS 0x09
diff --git a/drivers/s390/block/dasd_int.h b/drivers/s390/block/dasd_int.h
index 3c55c29155ef..c7223c4eba52 100644
--- a/drivers/s390/block/dasd_int.h
+++ b/drivers/s390/block/dasd_int.h
@@ -439,6 +439,7 @@ struct dasd_discipline {
int (*pprc_status)(struct dasd_device *, struct dasd_pprc_data_sc4 *);
bool (*pprc_enabled)(struct dasd_device *);
int (*copy_pair_swap)(struct dasd_device *, char *, char *);
+ int (*device_ping)(struct dasd_device *);
};
extern struct dasd_discipline *dasd_diag_discipline_pointer;
--
2.34.1
