diff options
Diffstat (limited to 'drivers/s390/cio/device.c')
| -rw-r--r-- | drivers/s390/cio/device.c | 237 |
1 files changed, 158 insertions, 79 deletions
diff --git a/drivers/s390/cio/device.c b/drivers/s390/cio/device.c index 4e4008325e2..23d5752349b 100644 --- a/drivers/s390/cio/device.c +++ b/drivers/s390/cio/device.c @@ -376,19 +376,23 @@ int ccw_device_set_offline(struct ccw_device *cdev) dev_fsm_event(cdev, DEV_EVENT_NOTOPER); } spin_unlock_irq(cdev->ccwlock); + /* Give up reference from ccw_device_set_online(). */ + put_device(&cdev->dev); return ret; } spin_unlock_irq(cdev->ccwlock); - if (ret == 0) + if (ret == 0) { wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev)); - else { + /* Give up reference from ccw_device_set_online(). */ + put_device(&cdev->dev); + } else { CIO_MSG_EVENT(0, "ccw_device_offline returned %d, " "device 0.%x.%04x\n", ret, cdev->private->dev_id.ssid, cdev->private->dev_id.devno); cdev->online = 1; } - return ret; + return ret; } /** @@ -411,6 +415,9 @@ int ccw_device_set_online(struct ccw_device *cdev) return -ENODEV; if (cdev->online || !cdev->drv) return -EINVAL; + /* Hold on to an extra reference while device is online. */ + if (!get_device(&cdev->dev)) + return -ENODEV; spin_lock_irq(cdev->ccwlock); ret = ccw_device_online(cdev); @@ -422,10 +429,15 @@ int ccw_device_set_online(struct ccw_device *cdev) "device 0.%x.%04x\n", ret, cdev->private->dev_id.ssid, cdev->private->dev_id.devno); + /* Give up online reference since onlining failed. */ + put_device(&cdev->dev); return ret; } - if (cdev->private->state != DEV_STATE_ONLINE) + if (cdev->private->state != DEV_STATE_ONLINE) { + /* Give up online reference since onlining failed. */ + put_device(&cdev->dev); return -ENODEV; + } if (!cdev->drv->set_online || cdev->drv->set_online(cdev) == 0) { cdev->online = 1; return 0; @@ -440,6 +452,8 @@ int ccw_device_set_online(struct ccw_device *cdev) "device 0.%x.%04x\n", ret, cdev->private->dev_id.ssid, cdev->private->dev_id.devno); + /* Give up online reference since onlining failed. */ + put_device(&cdev->dev); return (ret == 0) ? -ENODEV : ret; } @@ -704,6 +718,8 @@ ccw_device_release(struct device *dev) struct ccw_device *cdev; cdev = to_ccwdev(dev); + /* Release reference of parent subchannel. */ + put_device(cdev->dev.parent); kfree(cdev->private); kfree(cdev); } @@ -735,8 +751,8 @@ static int io_subchannel_initialize_dev(struct subchannel *sch, /* Do first half of device_register. */ device_initialize(&cdev->dev); if (!get_device(&sch->dev)) { - if (cdev->dev.release) - cdev->dev.release(&cdev->dev); + /* Release reference from device_initialize(). */ + put_device(&cdev->dev); return -ENODEV; } return 0; @@ -778,37 +794,55 @@ static void sch_attach_disconnected_device(struct subchannel *sch, struct subchannel *other_sch; int ret; - other_sch = to_subchannel(get_device(cdev->dev.parent)); + /* Get reference for new parent. */ + if (!get_device(&sch->dev)) + return; + other_sch = to_subchannel(cdev->dev.parent); + /* Note: device_move() changes cdev->dev.parent */ ret = device_move(&cdev->dev, &sch->dev); if (ret) { CIO_MSG_EVENT(0, "Moving disconnected device 0.%x.%04x failed " "(ret=%d)!\n", cdev->private->dev_id.ssid, cdev->private->dev_id.devno, ret); - put_device(&other_sch->dev); + /* Put reference for new parent. */ + put_device(&sch->dev); return; } sch_set_cdev(other_sch, NULL); /* No need to keep a subchannel without ccw device around. */ css_sch_device_unregister(other_sch); - put_device(&other_sch->dev); sch_attach_device(sch, cdev); + /* Put reference for old parent. */ + put_device(&other_sch->dev); } static void sch_attach_orphaned_device(struct subchannel *sch, struct ccw_device *cdev) { int ret; + struct subchannel *pseudo_sch; - /* Try to move the ccw device to its new subchannel. */ + /* Get reference for new parent. */ + if (!get_device(&sch->dev)) + return; + pseudo_sch = to_subchannel(cdev->dev.parent); + /* + * Try to move the ccw device to its new subchannel. + * Note: device_move() changes cdev->dev.parent + */ ret = device_move(&cdev->dev, &sch->dev); if (ret) { CIO_MSG_EVENT(0, "Moving device 0.%x.%04x from orphanage " "failed (ret=%d)!\n", cdev->private->dev_id.ssid, cdev->private->dev_id.devno, ret); + /* Put reference for new parent. */ + put_device(&sch->dev); return; } sch_attach_device(sch, cdev); + /* Put reference on pseudo subchannel. */ + put_device(&pseudo_sch->dev); } static void sch_create_and_recog_new_device(struct subchannel *sch) @@ -830,9 +864,11 @@ static void sch_create_and_recog_new_device(struct subchannel *sch) spin_lock_irq(sch->lock); sch_set_cdev(sch, NULL); spin_unlock_irq(sch->lock); - if (cdev->dev.release) - cdev->dev.release(&cdev->dev); css_sch_device_unregister(sch); + /* Put reference from io_subchannel_create_ccwdev(). */ + put_device(&sch->dev); + /* Give up initial reference. */ + put_device(&cdev->dev); } } @@ -854,15 +890,20 @@ void ccw_device_move_to_orphanage(struct work_struct *work) dev_id.devno = sch->schib.pmcw.dev; dev_id.ssid = sch->schid.ssid; + /* Increase refcount for pseudo subchannel. */ + get_device(&css->pseudo_subchannel->dev); /* * Move the orphaned ccw device to the orphanage so the replacing * ccw device can take its place on the subchannel. + * Note: device_move() changes cdev->dev.parent */ ret = device_move(&cdev->dev, &css->pseudo_subchannel->dev); if (ret) { CIO_MSG_EVENT(0, "Moving device 0.%x.%04x to orphanage failed " "(ret=%d)!\n", cdev->private->dev_id.ssid, cdev->private->dev_id.devno, ret); + /* Decrease refcount for pseudo subchannel again. */ + put_device(&css->pseudo_subchannel->dev); return; } cdev->ccwlock = css->pseudo_subchannel->lock; @@ -875,17 +916,23 @@ void ccw_device_move_to_orphanage(struct work_struct *work) if (replacing_cdev) { sch_attach_disconnected_device(sch, replacing_cdev); /* Release reference from get_disc_ccwdev_by_dev_id() */ - put_device(&cdev->dev); + put_device(&replacing_cdev->dev); + /* Release reference of subchannel from old cdev. */ + put_device(&sch->dev); return; } replacing_cdev = get_orphaned_ccwdev_by_dev_id(css, &dev_id); if (replacing_cdev) { sch_attach_orphaned_device(sch, replacing_cdev); /* Release reference from get_orphaned_ccwdev_by_dev_id() */ - put_device(&cdev->dev); + put_device(&replacing_cdev->dev); + /* Release reference of subchannel from old cdev. */ + put_device(&sch->dev); return; } sch_create_and_recog_new_device(sch); + /* Release reference of subchannel from old cdev. */ + put_device(&sch->dev); } /* @@ -903,6 +950,14 @@ io_subchannel_register(struct work_struct *work) priv = container_of(work, struct ccw_device_private, kick_work); cdev = priv->cdev; sch = to_subchannel(cdev->dev.parent); + /* + * Check if subchannel is still registered. It may have become + * unregistered if a machine check hit us after finishing + * device recognition but before the register work could be + * queued. + */ + if (!device_is_registered(&sch->dev)) + goto out_err; css_update_ssd_info(sch); /* * io_subchannel_register() will also be called after device @@ -910,7 +965,7 @@ io_subchannel_register(struct work_struct *work) * be registered). We need to reprobe since we may now have sense id * information. */ - if (klist_node_attached(&cdev->dev.knode_parent)) { + if (device_is_registered(&cdev->dev)) { if (!cdev->drv) { ret = device_reprobe(&cdev->dev); if (ret) @@ -934,22 +989,19 @@ io_subchannel_register(struct work_struct *work) CIO_MSG_EVENT(0, "Could not register ccw dev 0.%x.%04x: %d\n", cdev->private->dev_id.ssid, cdev->private->dev_id.devno, ret); - put_device(&cdev->dev); spin_lock_irqsave(sch->lock, flags); sch_set_cdev(sch, NULL); spin_unlock_irqrestore(sch->lock, flags); - kfree (cdev->private); - kfree (cdev); - put_device(&sch->dev); - if (atomic_dec_and_test(&ccw_device_init_count)) - wake_up(&ccw_device_init_wq); - return; + /* Release initial device reference. */ + put_device(&cdev->dev); + goto out_err; } - put_device(&cdev->dev); out: cdev->private->flags.recog_done = 1; - put_device(&sch->dev); wake_up(&cdev->private->wait_q); +out_err: + /* Release reference for workqueue processing. */ + put_device(&cdev->dev); if (atomic_dec_and_test(&ccw_device_init_count)) wake_up(&ccw_device_init_wq); } @@ -968,8 +1020,8 @@ static void ccw_device_call_sch_unregister(struct work_struct *work) sch = to_subchannel(cdev->dev.parent); css_sch_device_unregister(sch); /* Reset intparm to zeroes. */ - sch->schib.pmcw.intparm = 0; - cio_modify(sch); + sch->config.intparm = 0; + cio_commit_config(sch); /* Release cdev reference for workqueue processing.*/ put_device(&cdev->dev); /* Release subchannel reference for local processing. */ @@ -998,8 +1050,6 @@ io_subchannel_recog_done(struct ccw_device *cdev) PREPARE_WORK(&cdev->private->kick_work, ccw_device_call_sch_unregister); queue_work(slow_path_wq, &cdev->private->kick_work); - /* Release subchannel reference for asynchronous recognition. */ - put_device(&sch->dev); if (atomic_dec_and_test(&ccw_device_init_count)) wake_up(&ccw_device_init_wq); break; @@ -1070,10 +1120,15 @@ static void ccw_device_move_to_sch(struct work_struct *work) priv = container_of(work, struct ccw_device_private, kick_work); sch = priv->sch; cdev = priv->cdev; - former_parent = ccw_device_is_orphan(cdev) ? - NULL : to_subchannel(get_device(cdev->dev.parent)); + former_parent = to_subchannel(cdev->dev.parent); + /* Get reference for new parent. */ + if (!get_device(&sch->dev)) + return; mutex_lock(&sch->reg_mutex); - /* Try to move the ccw device to its new subchannel. */ + /* + * Try to move the ccw device to its new subchannel. + * Note: device_move() changes cdev->dev.parent + */ rc = device_move(&cdev->dev, &sch->dev); mutex_unlock(&sch->reg_mutex); if (rc) { @@ -1083,21 +1138,23 @@ static void ccw_device_move_to_sch(struct work_struct *work) cdev->private->dev_id.devno, sch->schid.ssid, sch->schid.sch_no, rc); css_sch_device_unregister(sch); + /* Put reference for new parent again. */ + put_device(&sch->dev); goto out; } - if (former_parent) { + if (!sch_is_pseudo_sch(former_parent)) { spin_lock_irq(former_parent->lock); sch_set_cdev(former_parent, NULL); spin_unlock_irq(former_parent->lock); css_sch_device_unregister(former_parent); /* Reset intparm to zeroes. */ - former_parent->schib.pmcw.intparm = 0; - cio_modify(former_parent); + former_parent->config.intparm = 0; + cio_commit_config(former_parent); } sch_attach_device(sch, cdev); out: - if (former_parent) - put_device(&former_parent->dev); + /* Put reference for old parent. */ + put_device(&former_parent->dev); put_device(&cdev->dev); } @@ -1113,6 +1170,15 @@ static void io_subchannel_irq(struct subchannel *sch) dev_fsm_event(cdev, DEV_EVENT_INTERRUPT); } +void io_subchannel_init_config(struct subchannel *sch) +{ + memset(&sch->config, 0, sizeof(sch->config)); + sch->config.csense = 1; + /* Use subchannel mp mode when there is more than 1 installed CHPID. */ + if ((sch->schib.pmcw.pim & (sch->schib.pmcw.pim - 1)) != 0) + sch->config.mp = 1; +} + static void io_subchannel_init_fields(struct subchannel *sch) { if (cio_is_console(sch->schid)) @@ -1127,18 +1193,34 @@ static void io_subchannel_init_fields(struct subchannel *sch) sch->schib.pmcw.dev, sch->schid.ssid, sch->schid.sch_no, sch->schib.pmcw.pim, sch->schib.pmcw.pam, sch->schib.pmcw.pom); - /* Initially set up some fields in the pmcw. */ - sch->schib.pmcw.ena = 0; - sch->schib.pmcw.csense = 1; /* concurrent sense */ - if ((sch->lpm & (sch->lpm - 1)) != 0) - sch->schib.pmcw.mp = 1; /* multipath mode */ - /* clean up possible residual cmf stuff */ - sch->schib.pmcw.mme = 0; - sch->schib.pmcw.mbfc = 0; - sch->schib.pmcw.mbi = 0; - sch->schib.mba = 0; + + io_subchannel_init_config(sch); } +static void io_subchannel_do_unreg(struct work_struct *work) +{ + struct subchannel *sch; + + sch = container_of(work, struct subchannel, work); + css_sch_device_unregister(sch); + /* Reset intparm to zeroes. */ + sch->config.intparm = 0; + cio_commit_config(sch); + put_device(&sch->dev); +} + +/* Schedule unregister if we have no cdev. */ +static void io_subchannel_schedule_removal(struct subchannel *sch) +{ + get_device(&sch->dev); + INIT_WORK(&sch->work, io_subchannel_do_unreg); + queue_work(slow_path_wq, &sch->work); +} + +/* + * Note: We always return 0 so that we bind to the device even on error. + * This is needed so that our remove function is called on unregister. + */ static int io_subchannel_probe(struct subchannel *sch) { struct ccw_device *cdev; @@ -1168,9 +1250,8 @@ static int io_subchannel_probe(struct subchannel *sch) ccw_device_register(cdev); /* * Check if the device is already online. If it is - * the reference count needs to be corrected - * (see ccw_device_online and css_init_done for the - * ugly details). + * the reference count needs to be corrected since we + * didn't obtain a reference in ccw_device_set_online. */ if (cdev->private->state != DEV_STATE_NOT_OPER && cdev->private->state != DEV_STATE_OFFLINE && @@ -1179,23 +1260,24 @@ static int io_subchannel_probe(struct subchannel *sch) return 0; } io_subchannel_init_fields(sch); - /* - * First check if a fitting device may be found amongst the - * disconnected devices or in the orphanage. - */ - dev_id.devno = sch->schib.pmcw.dev; - dev_id.ssid = sch->schid.ssid; + rc = cio_commit_config(sch); + if (rc) + goto out_schedule; rc = sysfs_create_group(&sch->dev.kobj, &io_subchannel_attr_group); if (rc) - return rc; + goto out_schedule; /* Allocate I/O subchannel private data. */ sch->private = kzalloc(sizeof(struct io_subchannel_private), GFP_KERNEL | GFP_DMA); - if (!sch->private) { - rc = -ENOMEM; + if (!sch->private) goto out_err; - } + /* + * First check if a fitting device may be found amongst the + * disconnected devices or in the orphanage. + */ + dev_id.devno = sch->schib.pmcw.dev; + dev_id.ssid = sch->schid.ssid; cdev = get_disc_ccwdev_by_dev_id(&dev_id, NULL); if (!cdev) cdev = get_orphaned_ccwdev_by_dev_id(to_css(sch->dev.parent), @@ -1213,24 +1295,21 @@ static int io_subchannel_probe(struct subchannel *sch) return 0; } cdev = io_subchannel_create_ccwdev(sch); - if (IS_ERR(cdev)) { - rc = PTR_ERR(cdev); + if (IS_ERR(cdev)) goto out_err; - } rc = io_subchannel_recog(cdev, sch); if (rc) { spin_lock_irqsave(sch->lock, flags); - sch_set_cdev(sch, NULL); + io_subchannel_recog_done(cdev); spin_unlock_irqrestore(sch->lock, flags); - if (cdev->dev.release) - cdev->dev.release(&cdev->dev); - goto out_err; } return 0; out_err: kfree(sch->private); sysfs_remove_group(&sch->dev.kobj, &io_subchannel_attr_group); - return rc; +out_schedule: + io_subchannel_schedule_removal(sch); + return 0; } static int @@ -1275,10 +1354,7 @@ static void io_subchannel_verify(struct subchannel *sch) static int check_for_io_on_path(struct subchannel *sch, int mask) { - int cc; - - cc = stsch(sch->schid, &sch->schib); - if (cc) + if (cio_update_schib(sch)) return 0; if (scsw_actl(&sch->schib.scsw) && sch->schib.pmcw.lpum == mask) return 1; @@ -1347,15 +1423,13 @@ static int io_subchannel_chp_event(struct subchannel *sch, io_subchannel_verify(sch); break; case CHP_OFFLINE: - if (stsch(sch->schid, &sch->schib)) - return -ENXIO; - if (!css_sch_is_valid(&sch->schib)) + if (cio_update_schib(sch)) return -ENODEV; io_subchannel_terminate_path(sch, mask); break; case CHP_ONLINE: - if (stsch(sch->schid, &sch->schib)) - return -ENXIO; + if (cio_update_schib(sch)) + return -ENODEV; sch->lpm |= mask & sch->opm; io_subchannel_verify(sch); break; @@ -1610,8 +1684,8 @@ static int io_subchannel_sch_event(struct subchannel *sch, int slow) spin_lock_irqsave(sch->lock, flags); /* Reset intparm to zeroes. */ - sch->schib.pmcw.intparm = 0; - cio_modify(sch); + sch->config.intparm = 0; + cio_commit_config(sch); break; case REPROBE: ccw_device_trigger_reprobe(cdev); @@ -1652,6 +1726,9 @@ static int ccw_device_console_enable(struct ccw_device *cdev, sch->private = cio_get_console_priv(); memset(sch->private, 0, sizeof(struct io_subchannel_private)); io_subchannel_init_fields(sch); + rc = cio_commit_config(sch); + if (rc) + return rc; sch->driver = &io_subchannel_driver; /* Initialize the ccw_device structure. */ cdev->dev.parent= &sch->dev; @@ -1723,7 +1800,7 @@ __ccwdev_check_busid(struct device *dev, void *id) bus_id = id; - return (strncmp(bus_id, dev_name(dev), BUS_ID_SIZE) == 0); + return (strcmp(bus_id, dev_name(dev)) == 0); } @@ -1806,6 +1883,8 @@ ccw_device_remove (struct device *dev) "device 0.%x.%04x\n", ret, cdev->private->dev_id.ssid, cdev->private->dev_id.devno); + /* Give up reference obtained in ccw_device_set_online(). */ + put_device(&cdev->dev); } ccw_device_set_timeout(cdev, 0); cdev->drv = NULL; |