940 lines
27 KiB
C
940 lines
27 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* PAV alias management for the DASD ECKD discipline
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*
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* Copyright IBM Corp. 2007
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* Author(s): Stefan Weinhuber <wein@de.ibm.com>
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*/
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#define KMSG_COMPONENT "dasd-eckd"
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#include <linux/list.h>
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#include <linux/slab.h>
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#include <asm/ebcdic.h>
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#include "dasd_int.h"
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#include "dasd_eckd.h"
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#ifdef PRINTK_HEADER
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#undef PRINTK_HEADER
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#endif /* PRINTK_HEADER */
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#define PRINTK_HEADER "dasd(eckd):"
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/*
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* General concept of alias management:
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* - PAV and DASD alias management is specific to the eckd discipline.
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* - A device is connected to an lcu as long as the device exists.
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* dasd_alias_make_device_known_to_lcu will be called wenn the
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* device is checked by the eckd discipline and
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* dasd_alias_disconnect_device_from_lcu will be called
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* before the device is deleted.
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* - The dasd_alias_add_device / dasd_alias_remove_device
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* functions mark the point when a device is 'ready for service'.
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* - A summary unit check is a rare occasion, but it is mandatory to
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* support it. It requires some complex recovery actions before the
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* devices can be used again (see dasd_alias_handle_summary_unit_check).
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* - dasd_alias_get_start_dev will find an alias device that can be used
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* instead of the base device and does some (very simple) load balancing.
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* This is the function that gets called for each I/O, so when improving
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* something, this function should get faster or better, the rest has just
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* to be correct.
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*/
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static void summary_unit_check_handling_work(struct work_struct *);
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static void lcu_update_work(struct work_struct *);
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static int _schedule_lcu_update(struct alias_lcu *, struct dasd_device *);
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static struct alias_root aliastree = {
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.serverlist = LIST_HEAD_INIT(aliastree.serverlist),
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.lock = __SPIN_LOCK_UNLOCKED(aliastree.lock),
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};
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static struct alias_server *_find_server(struct dasd_uid *uid)
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{
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struct alias_server *pos;
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list_for_each_entry(pos, &aliastree.serverlist, server) {
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if (!strncmp(pos->uid.vendor, uid->vendor,
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sizeof(uid->vendor))
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&& !strncmp(pos->uid.serial, uid->serial,
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sizeof(uid->serial)))
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return pos;
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}
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return NULL;
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}
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static struct alias_lcu *_find_lcu(struct alias_server *server,
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struct dasd_uid *uid)
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{
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struct alias_lcu *pos;
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list_for_each_entry(pos, &server->lculist, lcu) {
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if (pos->uid.ssid == uid->ssid)
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return pos;
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}
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return NULL;
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}
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static struct alias_pav_group *_find_group(struct alias_lcu *lcu,
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struct dasd_uid *uid)
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{
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struct alias_pav_group *pos;
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__u8 search_unit_addr;
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/* for hyper pav there is only one group */
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if (lcu->pav == HYPER_PAV) {
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if (list_empty(&lcu->grouplist))
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return NULL;
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else
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return list_first_entry(&lcu->grouplist,
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struct alias_pav_group, group);
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}
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/* for base pav we have to find the group that matches the base */
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if (uid->type == UA_BASE_DEVICE)
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search_unit_addr = uid->real_unit_addr;
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else
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search_unit_addr = uid->base_unit_addr;
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list_for_each_entry(pos, &lcu->grouplist, group) {
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if (pos->uid.base_unit_addr == search_unit_addr &&
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!strncmp(pos->uid.vduit, uid->vduit, sizeof(uid->vduit)))
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return pos;
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}
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return NULL;
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}
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static struct alias_server *_allocate_server(struct dasd_uid *uid)
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{
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struct alias_server *server;
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server = kzalloc(sizeof(*server), GFP_KERNEL);
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if (!server)
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return ERR_PTR(-ENOMEM);
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memcpy(server->uid.vendor, uid->vendor, sizeof(uid->vendor));
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memcpy(server->uid.serial, uid->serial, sizeof(uid->serial));
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INIT_LIST_HEAD(&server->server);
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INIT_LIST_HEAD(&server->lculist);
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return server;
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}
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static void _free_server(struct alias_server *server)
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{
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kfree(server);
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}
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static struct alias_lcu *_allocate_lcu(struct dasd_uid *uid)
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{
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struct alias_lcu *lcu;
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lcu = kzalloc(sizeof(*lcu), GFP_KERNEL);
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if (!lcu)
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return ERR_PTR(-ENOMEM);
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lcu->uac = kzalloc(sizeof(*(lcu->uac)), GFP_KERNEL | GFP_DMA);
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if (!lcu->uac)
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goto out_err1;
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lcu->rsu_cqr = kzalloc(sizeof(*lcu->rsu_cqr), GFP_KERNEL | GFP_DMA);
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if (!lcu->rsu_cqr)
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goto out_err2;
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lcu->rsu_cqr->cpaddr = kzalloc(sizeof(struct ccw1),
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GFP_KERNEL | GFP_DMA);
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if (!lcu->rsu_cqr->cpaddr)
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goto out_err3;
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lcu->rsu_cqr->data = kzalloc(16, GFP_KERNEL | GFP_DMA);
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if (!lcu->rsu_cqr->data)
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goto out_err4;
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memcpy(lcu->uid.vendor, uid->vendor, sizeof(uid->vendor));
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memcpy(lcu->uid.serial, uid->serial, sizeof(uid->serial));
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lcu->uid.ssid = uid->ssid;
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lcu->pav = NO_PAV;
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lcu->flags = NEED_UAC_UPDATE | UPDATE_PENDING;
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INIT_LIST_HEAD(&lcu->lcu);
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INIT_LIST_HEAD(&lcu->inactive_devices);
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INIT_LIST_HEAD(&lcu->active_devices);
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INIT_LIST_HEAD(&lcu->grouplist);
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INIT_WORK(&lcu->suc_data.worker, summary_unit_check_handling_work);
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INIT_DELAYED_WORK(&lcu->ruac_data.dwork, lcu_update_work);
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spin_lock_init(&lcu->lock);
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init_completion(&lcu->lcu_setup);
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return lcu;
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out_err4:
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kfree(lcu->rsu_cqr->cpaddr);
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out_err3:
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kfree(lcu->rsu_cqr);
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out_err2:
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kfree(lcu->uac);
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out_err1:
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kfree(lcu);
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return ERR_PTR(-ENOMEM);
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}
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static void _free_lcu(struct alias_lcu *lcu)
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{
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kfree(lcu->rsu_cqr->data);
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kfree(lcu->rsu_cqr->cpaddr);
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kfree(lcu->rsu_cqr);
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kfree(lcu->uac);
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kfree(lcu);
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}
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/*
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* This is the function that will allocate all the server and lcu data,
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* so this function must be called first for a new device.
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* If the return value is 1, the lcu was already known before, if it
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* is 0, this is a new lcu.
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* Negative return code indicates that something went wrong (e.g. -ENOMEM)
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*/
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int dasd_alias_make_device_known_to_lcu(struct dasd_device *device)
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{
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struct dasd_eckd_private *private = device->private;
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unsigned long flags;
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struct alias_server *server, *newserver;
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struct alias_lcu *lcu, *newlcu;
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struct dasd_uid uid;
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device->discipline->get_uid(device, &uid);
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spin_lock_irqsave(&aliastree.lock, flags);
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server = _find_server(&uid);
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if (!server) {
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spin_unlock_irqrestore(&aliastree.lock, flags);
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newserver = _allocate_server(&uid);
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if (IS_ERR(newserver))
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return PTR_ERR(newserver);
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spin_lock_irqsave(&aliastree.lock, flags);
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server = _find_server(&uid);
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if (!server) {
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list_add(&newserver->server, &aliastree.serverlist);
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server = newserver;
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} else {
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/* someone was faster */
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_free_server(newserver);
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}
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}
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lcu = _find_lcu(server, &uid);
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if (!lcu) {
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spin_unlock_irqrestore(&aliastree.lock, flags);
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newlcu = _allocate_lcu(&uid);
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if (IS_ERR(newlcu))
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return PTR_ERR(newlcu);
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spin_lock_irqsave(&aliastree.lock, flags);
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lcu = _find_lcu(server, &uid);
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if (!lcu) {
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list_add(&newlcu->lcu, &server->lculist);
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lcu = newlcu;
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} else {
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/* someone was faster */
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_free_lcu(newlcu);
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}
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}
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spin_lock(&lcu->lock);
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list_add(&device->alias_list, &lcu->inactive_devices);
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private->lcu = lcu;
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spin_unlock(&lcu->lock);
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spin_unlock_irqrestore(&aliastree.lock, flags);
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return 0;
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}
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/*
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* This function removes a device from the scope of alias management.
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* The complicated part is to make sure that it is not in use by
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* any of the workers. If necessary cancel the work.
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*/
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void dasd_alias_disconnect_device_from_lcu(struct dasd_device *device)
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{
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struct dasd_eckd_private *private = device->private;
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unsigned long flags;
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struct alias_lcu *lcu;
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struct alias_server *server;
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int was_pending;
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struct dasd_uid uid;
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lcu = private->lcu;
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/* nothing to do if already disconnected */
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if (!lcu)
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return;
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device->discipline->get_uid(device, &uid);
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spin_lock_irqsave(&lcu->lock, flags);
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list_del_init(&device->alias_list);
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/* make sure that the workers don't use this device */
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if (device == lcu->suc_data.device) {
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spin_unlock_irqrestore(&lcu->lock, flags);
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cancel_work_sync(&lcu->suc_data.worker);
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spin_lock_irqsave(&lcu->lock, flags);
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if (device == lcu->suc_data.device) {
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dasd_put_device(device);
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lcu->suc_data.device = NULL;
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}
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}
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was_pending = 0;
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if (device == lcu->ruac_data.device) {
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spin_unlock_irqrestore(&lcu->lock, flags);
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was_pending = 1;
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cancel_delayed_work_sync(&lcu->ruac_data.dwork);
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spin_lock_irqsave(&lcu->lock, flags);
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if (device == lcu->ruac_data.device) {
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dasd_put_device(device);
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lcu->ruac_data.device = NULL;
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}
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}
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private->lcu = NULL;
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spin_unlock_irqrestore(&lcu->lock, flags);
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spin_lock_irqsave(&aliastree.lock, flags);
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spin_lock(&lcu->lock);
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if (list_empty(&lcu->grouplist) &&
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list_empty(&lcu->active_devices) &&
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list_empty(&lcu->inactive_devices)) {
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list_del(&lcu->lcu);
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spin_unlock(&lcu->lock);
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_free_lcu(lcu);
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lcu = NULL;
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} else {
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if (was_pending)
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_schedule_lcu_update(lcu, NULL);
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spin_unlock(&lcu->lock);
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}
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server = _find_server(&uid);
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if (server && list_empty(&server->lculist)) {
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list_del(&server->server);
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_free_server(server);
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}
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spin_unlock_irqrestore(&aliastree.lock, flags);
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}
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/*
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* This function assumes that the unit address configuration stored
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* in the lcu is up to date and will update the device uid before
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* adding it to a pav group.
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*/
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static int _add_device_to_lcu(struct alias_lcu *lcu,
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struct dasd_device *device,
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struct dasd_device *pos)
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{
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struct dasd_eckd_private *private = device->private;
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struct alias_pav_group *group;
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struct dasd_uid uid;
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spin_lock(get_ccwdev_lock(device->cdev));
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private->uid.type = lcu->uac->unit[private->uid.real_unit_addr].ua_type;
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private->uid.base_unit_addr =
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lcu->uac->unit[private->uid.real_unit_addr].base_ua;
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uid = private->uid;
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spin_unlock(get_ccwdev_lock(device->cdev));
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/* if we have no PAV anyway, we don't need to bother with PAV groups */
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if (lcu->pav == NO_PAV) {
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list_move(&device->alias_list, &lcu->active_devices);
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return 0;
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}
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group = _find_group(lcu, &uid);
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if (!group) {
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group = kzalloc(sizeof(*group), GFP_ATOMIC);
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if (!group)
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return -ENOMEM;
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memcpy(group->uid.vendor, uid.vendor, sizeof(uid.vendor));
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memcpy(group->uid.serial, uid.serial, sizeof(uid.serial));
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group->uid.ssid = uid.ssid;
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if (uid.type == UA_BASE_DEVICE)
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group->uid.base_unit_addr = uid.real_unit_addr;
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else
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group->uid.base_unit_addr = uid.base_unit_addr;
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memcpy(group->uid.vduit, uid.vduit, sizeof(uid.vduit));
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INIT_LIST_HEAD(&group->group);
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INIT_LIST_HEAD(&group->baselist);
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INIT_LIST_HEAD(&group->aliaslist);
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list_add(&group->group, &lcu->grouplist);
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}
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if (uid.type == UA_BASE_DEVICE)
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list_move(&device->alias_list, &group->baselist);
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else
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list_move(&device->alias_list, &group->aliaslist);
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private->pavgroup = group;
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return 0;
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};
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static void _remove_device_from_lcu(struct alias_lcu *lcu,
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struct dasd_device *device)
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{
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struct dasd_eckd_private *private = device->private;
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struct alias_pav_group *group;
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list_move(&device->alias_list, &lcu->inactive_devices);
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group = private->pavgroup;
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if (!group)
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return;
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private->pavgroup = NULL;
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if (list_empty(&group->baselist) && list_empty(&group->aliaslist)) {
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list_del(&group->group);
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kfree(group);
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return;
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}
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if (group->next == device)
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group->next = NULL;
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};
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static int
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suborder_not_supported(struct dasd_ccw_req *cqr)
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{
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char *sense;
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char reason;
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char msg_format;
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char msg_no;
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sense = dasd_get_sense(&cqr->irb);
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if (!sense)
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return 0;
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reason = sense[0];
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msg_format = (sense[7] & 0xF0);
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msg_no = (sense[7] & 0x0F);
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/* command reject, Format 0 MSG 4 - invalid parameter */
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if ((reason == 0x80) && (msg_format == 0x00) && (msg_no == 0x04))
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return 1;
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return 0;
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}
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static int read_unit_address_configuration(struct dasd_device *device,
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struct alias_lcu *lcu)
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{
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struct dasd_psf_prssd_data *prssdp;
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struct dasd_ccw_req *cqr;
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struct ccw1 *ccw;
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int rc;
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unsigned long flags;
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cqr = dasd_kmalloc_request(DASD_ECKD_MAGIC, 1 /* PSF */ + 1 /* RSSD */,
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(sizeof(struct dasd_psf_prssd_data)),
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device);
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if (IS_ERR(cqr))
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return PTR_ERR(cqr);
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cqr->startdev = device;
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cqr->memdev = device;
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clear_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
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cqr->retries = 10;
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cqr->expires = 20 * HZ;
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/* Prepare for Read Subsystem Data */
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prssdp = (struct dasd_psf_prssd_data *) cqr->data;
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memset(prssdp, 0, sizeof(struct dasd_psf_prssd_data));
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prssdp->order = PSF_ORDER_PRSSD;
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prssdp->suborder = 0x0e; /* Read unit address configuration */
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/* all other bytes of prssdp must be zero */
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ccw = cqr->cpaddr;
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ccw->cmd_code = DASD_ECKD_CCW_PSF;
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ccw->count = sizeof(struct dasd_psf_prssd_data);
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ccw->flags |= CCW_FLAG_CC;
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ccw->cda = (__u32)(addr_t) prssdp;
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/* Read Subsystem Data - feature codes */
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memset(lcu->uac, 0, sizeof(*(lcu->uac)));
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ccw++;
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ccw->cmd_code = DASD_ECKD_CCW_RSSD;
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ccw->count = sizeof(*(lcu->uac));
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ccw->cda = (__u32)(addr_t) lcu->uac;
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cqr->buildclk = get_tod_clock();
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cqr->status = DASD_CQR_FILLED;
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/* need to unset flag here to detect race with summary unit check */
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spin_lock_irqsave(&lcu->lock, flags);
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lcu->flags &= ~NEED_UAC_UPDATE;
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spin_unlock_irqrestore(&lcu->lock, flags);
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do {
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rc = dasd_sleep_on(cqr);
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if (rc && suborder_not_supported(cqr))
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return -EOPNOTSUPP;
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} while (rc && (cqr->retries > 0));
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if (rc) {
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spin_lock_irqsave(&lcu->lock, flags);
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lcu->flags |= NEED_UAC_UPDATE;
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spin_unlock_irqrestore(&lcu->lock, flags);
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}
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dasd_kfree_request(cqr, cqr->memdev);
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return rc;
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}
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static int _lcu_update(struct dasd_device *refdev, struct alias_lcu *lcu)
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{
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unsigned long flags;
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struct alias_pav_group *pavgroup, *tempgroup;
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struct dasd_device *device, *tempdev;
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int i, rc;
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struct dasd_eckd_private *private;
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spin_lock_irqsave(&lcu->lock, flags);
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list_for_each_entry_safe(pavgroup, tempgroup, &lcu->grouplist, group) {
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list_for_each_entry_safe(device, tempdev, &pavgroup->baselist,
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alias_list) {
|
|
list_move(&device->alias_list, &lcu->active_devices);
|
|
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 = 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;
|
|
|
|
spin_lock_irqsave(&lcu->lock, flags);
|
|
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_irqrestore(&lcu->lock, 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);
|
|
if (!schedule_delayed_work(&lcu->ruac_data.dwork, 30*HZ))
|
|
dasd_put_device(device);
|
|
} else {
|
|
dasd_put_device(device);
|
|
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;
|
|
dasd_get_device(usedev);
|
|
lcu->ruac_data.device = usedev;
|
|
if (!schedule_delayed_work(&lcu->ruac_data.dwork, 0))
|
|
dasd_put_device(usedev);
|
|
return 0;
|
|
}
|
|
|
|
int dasd_alias_add_device(struct dasd_device *device)
|
|
{
|
|
struct dasd_eckd_private *private = device->private;
|
|
struct alias_lcu *lcu;
|
|
unsigned long flags;
|
|
int rc;
|
|
|
|
lcu = private->lcu;
|
|
rc = 0;
|
|
spin_lock_irqsave(&lcu->lock, flags);
|
|
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_irqrestore(&lcu->lock, flags);
|
|
return rc;
|
|
}
|
|
|
|
int dasd_alias_update_add_device(struct dasd_device *device)
|
|
{
|
|
struct dasd_eckd_private *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 = device->private;
|
|
struct alias_lcu *lcu = private->lcu;
|
|
unsigned long flags;
|
|
|
|
/* 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_eckd_private *alias_priv, *private = base_device->private;
|
|
struct alias_pav_group *group = private->pavgroup;
|
|
struct alias_lcu *lcu = private->lcu;
|
|
struct dasd_device *alias_device;
|
|
unsigned long flags;
|
|
|
|
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 = alias_device->private;
|
|
if ((alias_priv->count < private->count) && !alias_device->stopped &&
|
|
!test_bit(DASD_FLAG_OFFLINE, &alias_device->flags))
|
|
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 = CCW_FLAG_SLI;
|
|
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;
|
|
|
|
/* active and inactive list can contain alias as well as base devices */
|
|
list_for_each_entry(device, &lcu->active_devices, alias_list) {
|
|
private = device->private;
|
|
if (private->uid.type != UA_BASE_DEVICE)
|
|
continue;
|
|
dasd_schedule_block_bh(device->block);
|
|
dasd_schedule_device_bh(device);
|
|
}
|
|
list_for_each_entry(device, &lcu->inactive_devices, alias_list) {
|
|
private = device->private;
|
|
if (private->uid.type != UA_BASE_DEVICE)
|
|
continue;
|
|
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;
|
|
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 = 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);
|
|
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);
|
|
private = device->private;
|
|
private->pavgroup = NULL;
|
|
}
|
|
}
|
|
spin_unlock_irqrestore(&lcu->lock, flags);
|
|
}
|
|
|
|
static void _stop_all_devices_on_lcu(struct alias_lcu *lcu)
|
|
{
|
|
struct alias_pav_group *pavgroup;
|
|
struct dasd_device *device;
|
|
|
|
list_for_each_entry(device, &lcu->active_devices, alias_list) {
|
|
spin_lock(get_ccwdev_lock(device->cdev));
|
|
dasd_device_set_stop_bits(device, DASD_STOPPED_SU);
|
|
spin_unlock(get_ccwdev_lock(device->cdev));
|
|
}
|
|
list_for_each_entry(device, &lcu->inactive_devices, alias_list) {
|
|
spin_lock(get_ccwdev_lock(device->cdev));
|
|
dasd_device_set_stop_bits(device, DASD_STOPPED_SU);
|
|
spin_unlock(get_ccwdev_lock(device->cdev));
|
|
}
|
|
list_for_each_entry(pavgroup, &lcu->grouplist, group) {
|
|
list_for_each_entry(device, &pavgroup->baselist, alias_list) {
|
|
spin_lock(get_ccwdev_lock(device->cdev));
|
|
dasd_device_set_stop_bits(device, DASD_STOPPED_SU);
|
|
spin_unlock(get_ccwdev_lock(device->cdev));
|
|
}
|
|
list_for_each_entry(device, &pavgroup->aliaslist, alias_list) {
|
|
spin_lock(get_ccwdev_lock(device->cdev));
|
|
dasd_device_set_stop_bits(device, DASD_STOPPED_SU);
|
|
spin_unlock(get_ccwdev_lock(device->cdev));
|
|
}
|
|
}
|
|
}
|
|
|
|
static void _unstop_all_devices_on_lcu(struct alias_lcu *lcu)
|
|
{
|
|
struct alias_pav_group *pavgroup;
|
|
struct dasd_device *device;
|
|
|
|
list_for_each_entry(device, &lcu->active_devices, alias_list) {
|
|
spin_lock(get_ccwdev_lock(device->cdev));
|
|
dasd_device_remove_stop_bits(device, DASD_STOPPED_SU);
|
|
spin_unlock(get_ccwdev_lock(device->cdev));
|
|
}
|
|
list_for_each_entry(device, &lcu->inactive_devices, alias_list) {
|
|
spin_lock(get_ccwdev_lock(device->cdev));
|
|
dasd_device_remove_stop_bits(device, DASD_STOPPED_SU);
|
|
spin_unlock(get_ccwdev_lock(device->cdev));
|
|
}
|
|
list_for_each_entry(pavgroup, &lcu->grouplist, group) {
|
|
list_for_each_entry(device, &pavgroup->baselist, alias_list) {
|
|
spin_lock(get_ccwdev_lock(device->cdev));
|
|
dasd_device_remove_stop_bits(device, DASD_STOPPED_SU);
|
|
spin_unlock(get_ccwdev_lock(device->cdev));
|
|
}
|
|
list_for_each_entry(device, &pavgroup->aliaslist, alias_list) {
|
|
spin_lock(get_ccwdev_lock(device->cdev));
|
|
dasd_device_remove_stop_bits(device, DASD_STOPPED_SU);
|
|
spin_unlock(get_ccwdev_lock(device->cdev));
|
|
}
|
|
}
|
|
}
|
|
|
|
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;
|
|
dasd_put_device(device);
|
|
spin_unlock_irqrestore(&lcu->lock, flags);
|
|
}
|
|
|
|
void dasd_alias_handle_summary_unit_check(struct work_struct *work)
|
|
{
|
|
struct dasd_device *device = container_of(work, struct dasd_device,
|
|
suc_work);
|
|
struct dasd_eckd_private *private = device->private;
|
|
struct alias_lcu *lcu;
|
|
unsigned long flags;
|
|
|
|
lcu = private->lcu;
|
|
if (!lcu) {
|
|
DBF_DEV_EVENT(DBF_WARNING, device, "%s",
|
|
"device not ready to handle summary"
|
|
" unit check (no lcu structure)");
|
|
goto out;
|
|
}
|
|
spin_lock_irqsave(&lcu->lock, flags);
|
|
/* 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");
|
|
goto out_unlock;
|
|
}
|
|
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");
|
|
goto out_unlock;
|
|
}
|
|
_stop_all_devices_on_lcu(lcu);
|
|
/* prepare for lcu_update */
|
|
lcu->flags |= NEED_UAC_UPDATE | UPDATE_PENDING;
|
|
lcu->suc_data.reason = private->suc_reason;
|
|
lcu->suc_data.device = device;
|
|
dasd_get_device(device);
|
|
if (!schedule_work(&lcu->suc_data.worker))
|
|
dasd_put_device(device);
|
|
out_unlock:
|
|
spin_unlock_irqrestore(&lcu->lock, flags);
|
|
out:
|
|
clear_bit(DASD_FLAG_SUC, &device->flags);
|
|
dasd_put_device(device);
|
|
};
|