diff options
Diffstat (limited to 'drivers/s390/block/dasd_alias.c')
| -rw-r--r-- | drivers/s390/block/dasd_alias.c | 990 |
1 files changed, 990 insertions, 0 deletions
diff --git a/drivers/s390/block/dasd_alias.c b/drivers/s390/block/dasd_alias.c new file mode 100644 index 000000000..a2597e683 --- /dev/null +++ b/drivers/s390/block/dasd_alias.c @@ -0,0 +1,990 @@ +/* + * PAV alias management for the DASD ECKD discipline + * + * Copyright IBM Corp. 2007 + * Author(s): Stefan Weinhuber <wein@de.ibm.com> + */ + +#define KMSG_COMPONENT "dasd-eckd" + +#include <linux/list.h> +#include <linux/slab.h> +#include <asm/ebcdic.h> +#include "dasd_int.h" +#include "dasd_eckd.h" + +#ifdef PRINTK_HEADER +#undef PRINTK_HEADER +#endif /* PRINTK_HEADER */ +#define PRINTK_HEADER "dasd(eckd):" + + +/* + * General concept of alias management: + * - PAV and DASD alias management is specific to the eckd discipline. + * - A device is connected to an lcu as long as the device exists. + * dasd_alias_make_device_known_to_lcu will be called wenn the + * device is checked by the eckd discipline and + * dasd_alias_disconnect_device_from_lcu will be called + * before the device is deleted. + * - The dasd_alias_add_device / dasd_alias_remove_device + * functions mark the point when a device is 'ready for service'. + * - A summary unit check is a rare occasion, but it is mandatory to + * support it. It requires some complex recovery actions before the + * devices can be used again (see dasd_alias_handle_summary_unit_check). + * - dasd_alias_get_start_dev will find an alias device that can be used + * instead of the base device and does some (very simple) load balancing. + * This is the function that gets called for each I/O, so when improving + * something, this function should get faster or better, the rest has just + * to be correct. + */ + + +static void summary_unit_check_handling_work(struct work_struct *); +static void lcu_update_work(struct work_struct *); +static int _schedule_lcu_update(struct alias_lcu *, struct dasd_device *); + +static struct alias_root aliastree = { + .serverlist = LIST_HEAD_INIT(aliastree.serverlist), + .lock = __SPIN_LOCK_UNLOCKED(aliastree.lock), +}; + +static struct alias_server *_find_server(struct dasd_uid *uid) +{ + struct alias_server *pos; + list_for_each_entry(pos, &aliastree.serverlist, server) { + if (!strncmp(pos->uid.vendor, uid->vendor, + sizeof(uid->vendor)) + && !strncmp(pos->uid.serial, uid->serial, + sizeof(uid->serial))) + return pos; + }; + return NULL; +} + +static struct alias_lcu *_find_lcu(struct alias_server *server, + struct dasd_uid *uid) +{ + struct alias_lcu *pos; + list_for_each_entry(pos, &server->lculist, lcu) { + if (pos->uid.ssid == uid->ssid) + return pos; + }; + return NULL; +} + +static struct alias_pav_group *_find_group(struct alias_lcu *lcu, + struct dasd_uid *uid) +{ + struct alias_pav_group *pos; + __u8 search_unit_addr; + + /* for hyper pav there is only one group */ + if (lcu->pav == HYPER_PAV) { + if (list_empty(&lcu->grouplist)) + return NULL; + else + return list_first_entry(&lcu->grouplist, + struct alias_pav_group, group); + } + + /* for base pav we have to find the group that matches the base */ + if (uid->type == UA_BASE_DEVICE) + search_unit_addr = uid->real_unit_addr; + else + search_unit_addr = uid->base_unit_addr; + list_for_each_entry(pos, &lcu->grouplist, group) { + if (pos->uid.base_unit_addr == search_unit_addr && + !strncmp(pos->uid.vduit, uid->vduit, sizeof(uid->vduit))) + return pos; + }; + return NULL; +} + +static struct alias_server *_allocate_server(struct dasd_uid *uid) +{ + struct alias_server *server; + + server = kzalloc(sizeof(*server), GFP_KERNEL); + if (!server) + return ERR_PTR(-ENOMEM); + memcpy(server->uid.vendor, uid->vendor, sizeof(uid->vendor)); + memcpy(server->uid.serial, uid->serial, sizeof(uid->serial)); + INIT_LIST_HEAD(&server->server); + INIT_LIST_HEAD(&server->lculist); + return server; +} + +static void _free_server(struct alias_server *server) +{ + kfree(server); +} + +static struct alias_lcu *_allocate_lcu(struct dasd_uid *uid) +{ + struct alias_lcu *lcu; + + lcu = kzalloc(sizeof(*lcu), GFP_KERNEL); + if (!lcu) + return ERR_PTR(-ENOMEM); + lcu->uac = kzalloc(sizeof(*(lcu->uac)), GFP_KERNEL | GFP_DMA); + if (!lcu->uac) + goto out_err1; + lcu->rsu_cqr = kzalloc(sizeof(*lcu->rsu_cqr), GFP_KERNEL | GFP_DMA); + if (!lcu->rsu_cqr) + goto out_err2; + lcu->rsu_cqr->cpaddr = kzalloc(sizeof(struct ccw1), + GFP_KERNEL | GFP_DMA); + if (!lcu->rsu_cqr->cpaddr) + goto out_err3; + lcu->rsu_cqr->data = kzalloc(16, GFP_KERNEL | GFP_DMA); + if (!lcu->rsu_cqr->data) + goto out_err4; + + memcpy(lcu->uid.vendor, uid->vendor, sizeof(uid->vendor)); + memcpy(lcu->uid.serial, uid->serial, sizeof(uid->serial)); + lcu->uid.ssid = uid->ssid; + lcu->pav = NO_PAV; + lcu->flags = NEED_UAC_UPDATE | UPDATE_PENDING; + INIT_LIST_HEAD(&lcu->lcu); + INIT_LIST_HEAD(&lcu->inactive_devices); + INIT_LIST_HEAD(&lcu->active_devices); + INIT_LIST_HEAD(&lcu->grouplist); + INIT_WORK(&lcu->suc_data.worker, summary_unit_check_handling_work); + INIT_DELAYED_WORK(&lcu->ruac_data.dwork, lcu_update_work); + spin_lock_init(&lcu->lock); + init_completion(&lcu->lcu_setup); + return lcu; + +out_err4: + kfree(lcu->rsu_cqr->cpaddr); +out_err3: + kfree(lcu->rsu_cqr); +out_err2: + kfree(lcu->uac); +out_err1: + kfree(lcu); + return ERR_PTR(-ENOMEM); +} + +static void _free_lcu(struct alias_lcu *lcu) +{ + kfree(lcu->rsu_cqr->data); + kfree(lcu->rsu_cqr->cpaddr); + kfree(lcu->rsu_cqr); + kfree(lcu->uac); + kfree(lcu); +} + +/* + * This is the function that will allocate all the server and lcu data, + * so this function must be called first for a new device. + * If the return value is 1, the lcu was already known before, if it + * is 0, this is a new lcu. + * Negative return code indicates that something went wrong (e.g. -ENOMEM) + */ +int dasd_alias_make_device_known_to_lcu(struct dasd_device *device) +{ + struct dasd_eckd_private *private; + unsigned long flags; + struct alias_server *server, *newserver; + struct alias_lcu *lcu, *newlcu; + struct dasd_uid uid; + + private = (struct dasd_eckd_private *) device->private; + + device->discipline->get_uid(device, &uid); + spin_lock_irqsave(&aliastree.lock, flags); + server = _find_server(&uid); + if (!server) { + spin_unlock_irqrestore(&aliastree.lock, flags); + newserver = _allocate_server(&uid); + if (IS_ERR(newserver)) + return PTR_ERR(newserver); + spin_lock_irqsave(&aliastree.lock, flags); + server = _find_server(&uid); + if (!server) { + list_add(&newserver->server, &aliastree.serverlist); + server = newserver; + } else { + /* someone was faster */ + _free_server(newserver); + } + } + + lcu = _find_lcu(server, &uid); + if (!lcu) { + spin_unlock_irqrestore(&aliastree.lock, flags); + newlcu = _allocate_lcu(&uid); + if (IS_ERR(newlcu)) + return PTR_ERR(newlcu); + spin_lock_irqsave(&aliastree.lock, flags); + lcu = _find_lcu(server, &uid); + if (!lcu) { + list_add(&newlcu->lcu, &server->lculist); + lcu = newlcu; + } else { + /* someone was faster */ + _free_lcu(newlcu); + } + } + spin_lock(&lcu->lock); + list_add(&device->alias_list, &lcu->inactive_devices); + private->lcu = lcu; + spin_unlock(&lcu->lock); + spin_unlock_irqrestore(&aliastree.lock, flags); + + return 0; +} + +/* + * This function removes a device from the scope of alias management. + * The complicated part is to make sure that it is not in use by + * any of the workers. If necessary cancel the work. + */ +void dasd_alias_disconnect_device_from_lcu(struct dasd_device *device) +{ + struct dasd_eckd_private *private; + unsigned long flags; + struct alias_lcu *lcu; + struct alias_server *server; + int was_pending; + struct dasd_uid uid; + + private = (struct dasd_eckd_private *) device->private; + lcu = private->lcu; + /* nothing to do if already disconnected */ + if (!lcu) + return; + device->discipline->get_uid(device, &uid); + spin_lock_irqsave(&lcu->lock, flags); + list_del_init(&device->alias_list); + /* make sure that the workers don't use this device */ + if (device == lcu->suc_data.device) { + spin_unlock_irqrestore(&lcu->lock, flags); + cancel_work_sync(&lcu->suc_data.worker); + spin_lock_irqsave(&lcu->lock, flags); + if (device == lcu->suc_data.device) + lcu->suc_data.device = NULL; + } + was_pending = 0; + if (device == lcu->ruac_data.device) { + spin_unlock_irqrestore(&lcu->lock, flags); + was_pending = 1; + cancel_delayed_work_sync(&lcu->ruac_data.dwork); + spin_lock_irqsave(&lcu->lock, flags); + if (device == lcu->ruac_data.device) + lcu->ruac_data.device = NULL; + } + private->lcu = NULL; + spin_unlock_irqrestore(&lcu->lock, flags); + + spin_lock_irqsave(&aliastree.lock, flags); + spin_lock(&lcu->lock); + if (list_empty(&lcu->grouplist) && + list_empty(&lcu->active_devices) && + list_empty(&lcu->inactive_devices)) { + list_del(&lcu->lcu); + spin_unlock(&lcu->lock); + _free_lcu(lcu); + lcu = NULL; + } else { + if (was_pending) + _schedule_lcu_update(lcu, NULL); + spin_unlock(&lcu->lock); + } + server = _find_server(&uid); + if (server && list_empty(&server->lculist)) { + list_del(&server->server); + _free_server(server); + } + spin_unlock_irqrestore(&aliastree.lock, flags); +} + +/* + * This function assumes that the unit address configuration stored + * in the lcu is up to date and will update the device uid before + * adding it to a pav group. + */ + +static int _add_device_to_lcu(struct alias_lcu *lcu, + struct dasd_device *device, + struct dasd_device *pos) +{ + + struct dasd_eckd_private *private; + struct alias_pav_group *group; + struct dasd_uid uid; + unsigned long flags; + + private = (struct dasd_eckd_private *) device->private; + + /* only lock if not already locked */ + if (device != pos) + spin_lock_irqsave_nested(get_ccwdev_lock(device->cdev), flags, + CDEV_NESTED_SECOND); + private->uid.type = lcu->uac->unit[private->uid.real_unit_addr].ua_type; + private->uid.base_unit_addr = + lcu->uac->unit[private->uid.real_unit_addr].base_ua; + uid = private->uid; + + if (device != pos) + spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags); + + /* if we have no PAV anyway, we don't need to bother with PAV groups */ + if (lcu->pav == NO_PAV) { + list_move(&device->alias_list, &lcu->active_devices); + return 0; + } + + group = _find_group(lcu, &uid); + if (!group) { + group = kzalloc(sizeof(*group), GFP_ATOMIC); + if (!group) + return -ENOMEM; + memcpy(group->uid.vendor, uid.vendor, sizeof(uid.vendor)); + memcpy(group->uid.serial, uid.serial, sizeof(uid.serial)); + group->uid.ssid = uid.ssid; + if (uid.type == UA_BASE_DEVICE) + group->uid.base_unit_addr = uid.real_unit_addr; + else + group->uid.base_unit_addr = uid.base_unit_addr; + memcpy(group->uid.vduit, uid.vduit, sizeof(uid.vduit)); + INIT_LIST_HEAD(&group->group); + INIT_LIST_HEAD(&group->baselist); + INIT_LIST_HEAD(&group->aliaslist); + list_add(&group->group, &lcu->grouplist); + } + if (uid.type == UA_BASE_DEVICE) + list_move(&device->alias_list, &group->baselist); + else + list_move(&device->alias_list, &group->aliaslist); + private->pavgroup = group; + return 0; +}; + +static void _remove_device_from_lcu(struct alias_lcu *lcu, + struct dasd_device *device) +{ + struct dasd_eckd_private *private; + struct alias_pav_group *group; + + private = (struct dasd_eckd_private *) device->private; + list_move(&device->alias_list, &lcu->inactive_devices); + group = private->pavgroup; + if (!group) + return; + private->pavgroup = NULL; + if (list_empty(&group->baselist) && list_empty(&group->aliaslist)) { + list_del(&group->group); + kfree(group); + return; + } + if (group->next == device) + group->next = NULL; +}; + +static int +suborder_not_supported(struct dasd_ccw_req *cqr) +{ + char *sense; + char reason; + char msg_format; + char msg_no; + + sense = dasd_get_sense(&cqr->irb); + if (!sense) + return 0; + + reason = sense[0]; + msg_format = (sense[7] & 0xF0); + msg_no = (sense[7] & 0x0F); + + /* command reject, Format 0 MSG 4 - invalid parameter */ + if ((reason == 0x80) && (msg_format == 0x00) && (msg_no == 0x04)) + return 1; + + return 0; +} + +static int read_unit_address_configuration(struct dasd_device *device, + struct alias_lcu *lcu) +{ + struct dasd_psf_prssd_data *prssdp; + struct dasd_ccw_req *cqr; + struct ccw1 *ccw; + int rc; + unsigned long flags; + + cqr = dasd_kmalloc_request(DASD_ECKD_MAGIC, 1 /* PSF */ + 1 /* RSSD */, + (sizeof(struct dasd_psf_prssd_data)), + device); + if (IS_ERR(cqr)) + return PTR_ERR(cqr); + cqr->startdev = device; + cqr->memdev = device; + clear_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags); + cqr->retries = 10; + cqr->expires = 20 * HZ; + + /* Prepare for Read Subsystem Data */ + prssdp = (struct dasd_psf_prssd_data *) cqr->data; + memset(prssdp, 0, sizeof(struct dasd_psf_prssd_data)); + prssdp->order = PSF_ORDER_PRSSD; + prssdp->suborder = 0x0e; /* Read unit address configuration */ + /* all other bytes of prssdp must be zero */ + + ccw = cqr->cpaddr; + ccw->cmd_code = DASD_ECKD_CCW_PSF; + ccw->count = sizeof(struct dasd_psf_prssd_data); + ccw->flags |= CCW_FLAG_CC; + ccw->cda = (__u32)(addr_t) prssdp; + + /* Read Subsystem Data - feature codes */ + memset(lcu->uac, 0, sizeof(*(lcu->uac))); + + ccw++; + ccw->cmd_code = DASD_ECKD_CCW_RSSD; + ccw->count = sizeof(*(lcu->uac)); + ccw->cda = (__u32)(addr_t) lcu->uac; + + cqr->buildclk = get_tod_clock(); + cqr->status = DASD_CQR_FILLED; + + /* need to unset flag here to detect race with summary unit check */ + spin_lock_irqsave(&lcu->lock, flags); + lcu->flags &= ~NEED_UAC_UPDATE; + spin_unlock_irqrestore(&lcu->lock, flags); + + do { + rc = dasd_sleep_on(cqr); + if (rc && suborder_not_supported(cqr)) + return -EOPNOTSUPP; + } while (rc && (cqr->retries > 0)); + if (rc) { + spin_lock_irqsave(&lcu->lock, flags); + lcu->flags |= NEED_UAC_UPDATE; + spin_unlock_irqrestore(&lcu->lock, flags); + } + dasd_kfree_request(cqr, cqr->memdev); + return rc; +} + +static int _lcu_update(struct dasd_device *refdev, struct alias_lcu *lcu) +{ + unsigned long flags; + struct alias_pav_group *pavgroup, *tempgroup; + struct dasd_device *device, *tempdev; + int i, rc; + struct dasd_eckd_private *private; + + spin_lock_irqsave(&lcu->lock, flags); + list_for_each_entry_safe(pavgroup, tempgroup, &lcu->grouplist, group) { + list_for_each_entry_safe(device, tempdev, &pavgroup->baselist, + alias_list) { + list_move(&device->alias_list, &lcu->active_devices); + private = (struct dasd_eckd_private *) device->private; + private->pavgroup = NULL; + } + list_for_each_entry_safe(device, tempdev, &pavgroup->aliaslist, + alias_list) { + list_move(&device->alias_list, &lcu->active_devices); + private = (struct dasd_eckd_private *) device->private; + private->pavgroup = NULL; + } + list_del(&pavgroup->group); + kfree(pavgroup); + } + spin_unlock_irqrestore(&lcu->lock, flags); + + rc = read_unit_address_configuration(refdev, lcu); + if (rc) + return rc; + + /* need to take cdev lock before lcu lock */ + spin_lock_irqsave_nested(get_ccwdev_lock(refdev->cdev), flags, + CDEV_NESTED_FIRST); + spin_lock(&lcu->lock); + lcu->pav = NO_PAV; + for (i = 0; i < MAX_DEVICES_PER_LCU; ++i) { + switch (lcu->uac->unit[i].ua_type) { + case UA_BASE_PAV_ALIAS: + lcu->pav = BASE_PAV; + break; + case UA_HYPER_PAV_ALIAS: + lcu->pav = HYPER_PAV; + break; + } + if (lcu->pav != NO_PAV) + break; + } + + list_for_each_entry_safe(device, tempdev, &lcu->active_devices, + alias_list) { + _add_device_to_lcu(lcu, device, refdev); + } + spin_unlock(&lcu->lock); + spin_unlock_irqrestore(get_ccwdev_lock(refdev->cdev), flags); + return 0; +} + +static void lcu_update_work(struct work_struct *work) +{ + struct alias_lcu *lcu; + struct read_uac_work_data *ruac_data; + struct dasd_device *device; + unsigned long flags; + int rc; + + ruac_data = container_of(work, struct read_uac_work_data, dwork.work); + lcu = container_of(ruac_data, struct alias_lcu, ruac_data); + device = ruac_data->device; + rc = _lcu_update(device, lcu); + /* + * Need to check flags again, as there could have been another + * prepare_update or a new device a new device while we were still + * processing the data + */ + spin_lock_irqsave(&lcu->lock, flags); + if ((rc && (rc != -EOPNOTSUPP)) || (lcu->flags & NEED_UAC_UPDATE)) { + DBF_DEV_EVENT(DBF_WARNING, device, "could not update" + " alias data in lcu (rc = %d), retry later", rc); + schedule_delayed_work(&lcu->ruac_data.dwork, 30*HZ); + } else { + lcu->ruac_data.device = NULL; + lcu->flags &= ~UPDATE_PENDING; + } + spin_unlock_irqrestore(&lcu->lock, flags); +} + +static int _schedule_lcu_update(struct alias_lcu *lcu, + struct dasd_device *device) +{ + struct dasd_device *usedev = NULL; + struct alias_pav_group *group; + + lcu->flags |= NEED_UAC_UPDATE; + if (lcu->ruac_data.device) { + /* already scheduled or running */ + return 0; + } + if (device && !list_empty(&device->alias_list)) + usedev = device; + + if (!usedev && !list_empty(&lcu->grouplist)) { + group = list_first_entry(&lcu->grouplist, + struct alias_pav_group, group); + if (!list_empty(&group->baselist)) + usedev = list_first_entry(&group->baselist, + struct dasd_device, + alias_list); + else if (!list_empty(&group->aliaslist)) + usedev = list_first_entry(&group->aliaslist, + struct dasd_device, + alias_list); + } + if (!usedev && !list_empty(&lcu->active_devices)) { + usedev = list_first_entry(&lcu->active_devices, + struct dasd_device, alias_list); + } + /* + * if we haven't found a proper device yet, give up for now, the next + * device that will be set active will trigger an lcu update + */ + if (!usedev) + return -EINVAL; + lcu->ruac_data.device = usedev; + schedule_delayed_work(&lcu->ruac_data.dwork, 0); + return 0; +} + +int dasd_alias_add_device(struct dasd_device *device) +{ + struct dasd_eckd_private *private; + struct alias_lcu *lcu; + unsigned long flags; + int rc; + + private = (struct dasd_eckd_private *) device->private; + lcu = private->lcu; + rc = 0; + + /* need to take cdev lock before lcu lock */ + spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags); + spin_lock(&lcu->lock); + if (!(lcu->flags & UPDATE_PENDING)) { + rc = _add_device_to_lcu(lcu, device, device); + if (rc) + lcu->flags |= UPDATE_PENDING; + } + if (lcu->flags & UPDATE_PENDING) { + list_move(&device->alias_list, &lcu->active_devices); + _schedule_lcu_update(lcu, device); + } + spin_unlock(&lcu->lock); + spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags); + return rc; +} + +int dasd_alias_update_add_device(struct dasd_device *device) +{ + struct dasd_eckd_private *private; + private = (struct dasd_eckd_private *) device->private; + private->lcu->flags |= UPDATE_PENDING; + return dasd_alias_add_device(device); +} + +int dasd_alias_remove_device(struct dasd_device *device) +{ + struct dasd_eckd_private *private; + struct alias_lcu *lcu; + unsigned long flags; + + private = (struct dasd_eckd_private *) device->private; + lcu = private->lcu; + /* nothing to do if already removed */ + if (!lcu) + return 0; + spin_lock_irqsave(&lcu->lock, flags); + _remove_device_from_lcu(lcu, device); + spin_unlock_irqrestore(&lcu->lock, flags); + return 0; +} + +struct dasd_device *dasd_alias_get_start_dev(struct dasd_device *base_device) +{ + + struct dasd_device *alias_device; + struct alias_pav_group *group; + struct alias_lcu *lcu; + struct dasd_eckd_private *private, *alias_priv; + unsigned long flags; + + private = (struct dasd_eckd_private *) base_device->private; + group = private->pavgroup; + lcu = private->lcu; + if (!group || !lcu) + return NULL; + if (lcu->pav == NO_PAV || + lcu->flags & (NEED_UAC_UPDATE | UPDATE_PENDING)) + return NULL; + if (unlikely(!(private->features.feature[8] & 0x01))) { + /* + * PAV enabled but prefix not, very unlikely + * seems to be a lost pathgroup + * use base device to do IO + */ + DBF_DEV_EVENT(DBF_ERR, base_device, "%s", + "Prefix not enabled with PAV enabled\n"); + return NULL; + } + + spin_lock_irqsave(&lcu->lock, flags); + alias_device = group->next; + if (!alias_device) { + if (list_empty(&group->aliaslist)) { + spin_unlock_irqrestore(&lcu->lock, flags); + return NULL; + } else { + alias_device = list_first_entry(&group->aliaslist, + struct dasd_device, + alias_list); + } + } + if (list_is_last(&alias_device->alias_list, &group->aliaslist)) + group->next = list_first_entry(&group->aliaslist, + struct dasd_device, alias_list); + else + group->next = list_first_entry(&alias_device->alias_list, + struct dasd_device, alias_list); + spin_unlock_irqrestore(&lcu->lock, flags); + alias_priv = (struct dasd_eckd_private *) alias_device->private; + if ((alias_priv->count < private->count) && !alias_device->stopped) + return alias_device; + else + return NULL; +} + +/* + * Summary unit check handling depends on the way alias devices + * are handled so it is done here rather then in dasd_eckd.c + */ +static int reset_summary_unit_check(struct alias_lcu *lcu, + struct dasd_device *device, + char reason) +{ + struct dasd_ccw_req *cqr; + int rc = 0; + struct ccw1 *ccw; + + cqr = lcu->rsu_cqr; + strncpy((char *) &cqr->magic, "ECKD", 4); + ASCEBC((char *) &cqr->magic, 4); + ccw = cqr->cpaddr; + ccw->cmd_code = DASD_ECKD_CCW_RSCK; + ccw->flags = 0 ; + ccw->count = 16; + ccw->cda = (__u32)(addr_t) cqr->data; + ((char *)cqr->data)[0] = reason; + + clear_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags); + cqr->retries = 255; /* set retry counter to enable basic ERP */ + cqr->startdev = device; + cqr->memdev = device; + cqr->block = NULL; + cqr->expires = 5 * HZ; + cqr->buildclk = get_tod_clock(); + cqr->status = DASD_CQR_FILLED; + + rc = dasd_sleep_on_immediatly(cqr); + return rc; +} + +static void _restart_all_base_devices_on_lcu(struct alias_lcu *lcu) +{ + struct alias_pav_group *pavgroup; + struct dasd_device *device; + struct dasd_eckd_private *private; + unsigned long flags; + + /* active and inactive list can contain alias as well as base devices */ + list_for_each_entry(device, &lcu->active_devices, alias_list) { + private = (struct dasd_eckd_private *) device->private; + spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags); + if (private->uid.type != UA_BASE_DEVICE) { + spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), + flags); + continue; + } + spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags); + dasd_schedule_block_bh(device->block); + dasd_schedule_device_bh(device); + } + list_for_each_entry(device, &lcu->inactive_devices, alias_list) { + private = (struct dasd_eckd_private *) device->private; + spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags); + if (private->uid.type != UA_BASE_DEVICE) { + spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), + flags); + continue; + } + spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags); + dasd_schedule_block_bh(device->block); + dasd_schedule_device_bh(device); + } + list_for_each_entry(pavgroup, &lcu->grouplist, group) { + list_for_each_entry(device, &pavgroup->baselist, alias_list) { + dasd_schedule_block_bh(device->block); + dasd_schedule_device_bh(device); + } + } +} + +static void flush_all_alias_devices_on_lcu(struct alias_lcu *lcu) +{ + struct alias_pav_group *pavgroup; + struct dasd_device *device, *temp; + struct dasd_eckd_private *private; + int rc; + unsigned long flags; + LIST_HEAD(active); + + /* + * Problem here ist that dasd_flush_device_queue may wait + * for termination of a request to complete. We can't keep + * the lcu lock during that time, so we must assume that + * the lists may have changed. + * Idea: first gather all active alias devices in a separate list, + * then flush the first element of this list unlocked, and afterwards + * check if it is still on the list before moving it to the + * active_devices list. + */ + + spin_lock_irqsave(&lcu->lock, flags); + list_for_each_entry_safe(device, temp, &lcu->active_devices, + alias_list) { + private = (struct dasd_eckd_private *) device->private; + if (private->uid.type == UA_BASE_DEVICE) + continue; + list_move(&device->alias_list, &active); + } + + list_for_each_entry(pavgroup, &lcu->grouplist, group) { + list_splice_init(&pavgroup->aliaslist, &active); + } + while (!list_empty(&active)) { + device = list_first_entry(&active, struct dasd_device, + alias_list); + spin_unlock_irqrestore(&lcu->lock, flags); + rc = dasd_flush_device_queue(device); + spin_lock_irqsave(&lcu->lock, flags); + /* + * only move device around if it wasn't moved away while we + * were waiting for the flush + */ + if (device == list_first_entry(&active, + struct dasd_device, alias_list)) + list_move(&device->alias_list, &lcu->active_devices); + } + spin_unlock_irqrestore(&lcu->lock, flags); +} + +static void __stop_device_on_lcu(struct dasd_device *device, + struct dasd_device *pos) +{ + /* If pos == device then device is already locked! */ + if (pos == device) { + dasd_device_set_stop_bits(pos, DASD_STOPPED_SU); + return; + } + spin_lock(get_ccwdev_lock(pos->cdev)); + dasd_device_set_stop_bits(pos, DASD_STOPPED_SU); + spin_unlock(get_ccwdev_lock(pos->cdev)); +} + +/* + * This function is called in interrupt context, so the + * cdev lock for device is already locked! + */ +static void _stop_all_devices_on_lcu(struct alias_lcu *lcu, + struct dasd_device *device) +{ + struct alias_pav_group *pavgroup; + struct dasd_device *pos; + + list_for_each_entry(pos, &lcu->active_devices, alias_list) + __stop_device_on_lcu(device, pos); + list_for_each_entry(pos, &lcu->inactive_devices, alias_list) + __stop_device_on_lcu(device, pos); + list_for_each_entry(pavgroup, &lcu->grouplist, group) { + list_for_each_entry(pos, &pavgroup->baselist, alias_list) + __stop_device_on_lcu(device, pos); + list_for_each_entry(pos, &pavgroup->aliaslist, alias_list) + __stop_device_on_lcu(device, pos); + } +} + +static void _unstop_all_devices_on_lcu(struct alias_lcu *lcu) +{ + struct alias_pav_group *pavgroup; + struct dasd_device *device; + unsigned long flags; + + list_for_each_entry(device, &lcu->active_devices, alias_list) { + spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags); + dasd_device_remove_stop_bits(device, DASD_STOPPED_SU); + spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags); + } + + list_for_each_entry(device, &lcu->inactive_devices, alias_list) { + spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags); + dasd_device_remove_stop_bits(device, DASD_STOPPED_SU); + spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags); + } + + list_for_each_entry(pavgroup, &lcu->grouplist, group) { + list_for_each_entry(device, &pavgroup->baselist, alias_list) { + spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags); + dasd_device_remove_stop_bits(device, DASD_STOPPED_SU); + spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), + flags); + } + list_for_each_entry(device, &pavgroup->aliaslist, alias_list) { + spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags); + dasd_device_remove_stop_bits(device, DASD_STOPPED_SU); + spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), + flags); + } + } +} + +static void summary_unit_check_handling_work(struct work_struct *work) +{ + struct alias_lcu *lcu; + struct summary_unit_check_work_data *suc_data; + unsigned long flags; + struct dasd_device *device; + + suc_data = container_of(work, struct summary_unit_check_work_data, + worker); + lcu = container_of(suc_data, struct alias_lcu, suc_data); + device = suc_data->device; + + /* 1. flush alias devices */ + flush_all_alias_devices_on_lcu(lcu); + + /* 2. reset summary unit check */ + spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags); + dasd_device_remove_stop_bits(device, + (DASD_STOPPED_SU | DASD_STOPPED_PENDING)); + spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags); + reset_summary_unit_check(lcu, device, suc_data->reason); + + spin_lock_irqsave(&lcu->lock, flags); + _unstop_all_devices_on_lcu(lcu); + _restart_all_base_devices_on_lcu(lcu); + /* 3. read new alias configuration */ + _schedule_lcu_update(lcu, device); + lcu->suc_data.device = NULL; + spin_unlock_irqrestore(&lcu->lock, flags); +} + +/* + * note: this will be called from int handler context (cdev locked) + */ +void dasd_alias_handle_summary_unit_check(struct dasd_device *device, + struct irb *irb) +{ + struct alias_lcu *lcu; + char reason; + struct dasd_eckd_private *private; + char *sense; + + private = (struct dasd_eckd_private *) device->private; + + sense = dasd_get_sense(irb); + if (sense) { + reason = sense[8]; + DBF_DEV_EVENT(DBF_NOTICE, device, "%s %x", + "eckd handle summary unit check: reason", reason); + } else { + DBF_DEV_EVENT(DBF_WARNING, device, "%s", + "eckd handle summary unit check:" + " no reason code available"); + return; + } + + lcu = private->lcu; + if (!lcu) { + DBF_DEV_EVENT(DBF_WARNING, device, "%s", + "device not ready to handle summary" + " unit check (no lcu structure)"); + return; + } + spin_lock(&lcu->lock); + _stop_all_devices_on_lcu(lcu, device); + /* prepare for lcu_update */ + private->lcu->flags |= NEED_UAC_UPDATE | UPDATE_PENDING; + /* If this device is about to be removed just return and wait for + * the next interrupt on a different device + */ + if (list_empty(&device->alias_list)) { + DBF_DEV_EVENT(DBF_WARNING, device, "%s", + "device is in offline processing," + " don't do summary unit check handling"); + spin_unlock(&lcu->lock); + return; + } + if (lcu->suc_data.device) { + /* already scheduled or running */ + DBF_DEV_EVENT(DBF_WARNING, device, "%s", + "previous instance of summary unit check worker" + " still pending"); + spin_unlock(&lcu->lock); + return ; + } + lcu->suc_data.reason = reason; + lcu->suc_data.device = device; + spin_unlock(&lcu->lock); + schedule_work(&lcu->suc_data.worker); +}; |