From 32ff8ce08b47a5fe64ef9827443ba6cc49a659c8 Mon Sep 17 00:00:00 2001 From: Stefan Haberland Date: Tue, 20 Sep 2022 21:26:16 +0200 Subject: s390/dasd: add device ping attribute 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 Reviewed-by: Jan Hoeppner Link: https://lore.kernel.org/r/20220920192616.808070-8-sth@linux.ibm.com Signed-off-by: Jens Axboe --- 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 @@ out: } 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; -- cgit v1.2.3