From d7b5a4c94f49131811112526f7d404a50f0b5ca7 Mon Sep 17 00:00:00 2001 From: Cornelia Huck Date: Fri, 8 Dec 2006 15:54:28 +0100 Subject: [PATCH] [S390] Support for disconnected devices reappearing on another subchannel. - create a 'pseudo_subchannel' per channel subsystem (the 'orphanage') - use the orphanage as a shelter for ccw_devices that can't remain on the same subchannel Signed-off-by: Cornelia Huck Cc: Greg KH Signed-off-by: Andrew Morton Signed-off-by: Martin Schwidefsky --- drivers/s390/cio/cio.c | 6 +- drivers/s390/cio/cio.h | 2 + drivers/s390/cio/css.c | 37 ++++- drivers/s390/cio/css.h | 4 + drivers/s390/cio/device.c | 285 ++++++++++++++++++++++++++++------ drivers/s390/cio/device.h | 2 + drivers/s390/cio/device_fsm.c | 17 +- 7 files changed, 295 insertions(+), 58 deletions(-) diff --git a/drivers/s390/cio/cio.c b/drivers/s390/cio/cio.c index e8d331493fd8..7835a714a405 100644 --- a/drivers/s390/cio/cio.c +++ b/drivers/s390/cio/cio.c @@ -415,6 +415,8 @@ cio_enable_subchannel (struct subchannel *sch, unsigned int isc) CIO_TRACE_EVENT (2, "ensch"); CIO_TRACE_EVENT (2, sch->dev.bus_id); + if (sch_is_pseudo_sch(sch)) + return -EINVAL; ccode = stsch (sch->schid, &sch->schib); if (ccode) return -ENODEV; @@ -462,6 +464,8 @@ cio_disable_subchannel (struct subchannel *sch) CIO_TRACE_EVENT (2, "dissch"); CIO_TRACE_EVENT (2, sch->dev.bus_id); + if (sch_is_pseudo_sch(sch)) + return 0; ccode = stsch (sch->schid, &sch->schib); if (ccode == 3) /* Not operational. */ return -ENODEV; @@ -496,7 +500,7 @@ cio_disable_subchannel (struct subchannel *sch) return ret; } -static int cio_create_sch_lock(struct subchannel *sch) +int cio_create_sch_lock(struct subchannel *sch) { sch->lock = kmalloc(sizeof(spinlock_t), GFP_KERNEL); if (!sch->lock) diff --git a/drivers/s390/cio/cio.h b/drivers/s390/cio/cio.h index 7e7369b21a93..35154a210357 100644 --- a/drivers/s390/cio/cio.h +++ b/drivers/s390/cio/cio.h @@ -131,6 +131,8 @@ extern int cio_set_options (struct subchannel *, int); extern int cio_get_options (struct subchannel *); extern int cio_modify (struct subchannel *); +int cio_create_sch_lock(struct subchannel *); + /* Use with care. */ #ifdef CONFIG_CCW_CONSOLE extern struct subchannel *cio_probe_console(void); diff --git a/drivers/s390/cio/css.c b/drivers/s390/cio/css.c index 65939e2eb415..0bf716619378 100644 --- a/drivers/s390/cio/css.c +++ b/drivers/s390/cio/css.c @@ -580,12 +580,24 @@ css_cm_enable_store(struct device *dev, struct device_attribute *attr, static DEVICE_ATTR(cm_enable, 0644, css_cm_enable_show, css_cm_enable_store); -static inline void __init -setup_css(int nr) +static inline int __init setup_css(int nr) { u32 tod_high; + int ret; memset(css[nr], 0, sizeof(struct channel_subsystem)); + css[nr]->pseudo_subchannel = + kzalloc(sizeof(*css[nr]->pseudo_subchannel), GFP_KERNEL); + if (!css[nr]->pseudo_subchannel) + return -ENOMEM; + css[nr]->pseudo_subchannel->dev.parent = &css[nr]->device; + css[nr]->pseudo_subchannel->dev.release = css_subchannel_release; + sprintf(css[nr]->pseudo_subchannel->dev.bus_id, "defunct"); + ret = cio_create_sch_lock(css[nr]->pseudo_subchannel); + if (ret) { + kfree(css[nr]->pseudo_subchannel); + return ret; + } mutex_init(&css[nr]->mutex); css[nr]->valid = 1; css[nr]->cssid = nr; @@ -593,6 +605,7 @@ setup_css(int nr) css[nr]->device.release = channel_subsystem_release; tod_high = (u32) (get_clock() >> 32); css_generate_pgid(css[nr], tod_high); + return 0; } /* @@ -629,10 +642,12 @@ init_channel_subsystem (void) ret = -ENOMEM; goto out_unregister; } - setup_css(i); - ret = device_register(&css[i]->device); + ret = setup_css(i); if (ret) goto out_free; + ret = device_register(&css[i]->device); + if (ret) + goto out_free_all; if (css_characteristics_avail && css_chsc_characteristics.secm) { ret = device_create_file(&css[i]->device, @@ -640,6 +655,9 @@ init_channel_subsystem (void) if (ret) goto out_device; } + ret = device_register(&css[i]->pseudo_subchannel->dev); + if (ret) + goto out_file; } css_init_done = 1; @@ -647,13 +665,19 @@ init_channel_subsystem (void) for_each_subchannel(__init_channel_subsystem, NULL); return 0; +out_file: + device_remove_file(&css[i]->device, &dev_attr_cm_enable); out_device: device_unregister(&css[i]->device); +out_free_all: + kfree(css[i]->pseudo_subchannel->lock); + kfree(css[i]->pseudo_subchannel); out_free: kfree(css[i]); out_unregister: while (i > 0) { i--; + device_unregister(&css[i]->pseudo_subchannel->dev); if (css_characteristics_avail && css_chsc_characteristics.secm) device_remove_file(&css[i]->device, &dev_attr_cm_enable); @@ -665,6 +689,11 @@ out: return ret; } +int sch_is_pseudo_sch(struct subchannel *sch) +{ + return sch == to_css(sch->dev.parent)->pseudo_subchannel; +} + /* * find a driver for a subchannel. They identify by the subchannel * type with the exception that the console subchannel driver has its own diff --git a/drivers/s390/cio/css.h b/drivers/s390/cio/css.h index ac845c1ebf83..71fe380f86f6 100644 --- a/drivers/s390/cio/css.h +++ b/drivers/s390/cio/css.h @@ -160,6 +160,8 @@ struct channel_subsystem { int cm_enabled; void *cub_addr1; void *cub_addr2; + /* for orphaned ccw devices */ + struct subchannel *pseudo_subchannel; }; #define to_css(dev) container_of(dev, struct channel_subsystem, device) @@ -187,6 +189,8 @@ void css_clear_subchannel_slow_list(void); int css_slow_subchannels_exist(void); extern int need_rescan; +int sch_is_pseudo_sch(struct subchannel *); + extern struct workqueue_struct *slow_path_wq; extern struct work_struct slow_path_work; diff --git a/drivers/s390/cio/device.c b/drivers/s390/cio/device.c index 9a31239fe028..7fe1ccdc7812 100644 --- a/drivers/s390/cio/device.c +++ b/drivers/s390/cio/device.c @@ -23,6 +23,7 @@ #include /* HZ */ #include "cio.h" +#include "cio_debug.h" #include "css.h" #include "device.h" #include "ioasm.h" @@ -294,6 +295,11 @@ online_show (struct device *dev, struct device_attribute *attr, char *buf) return sprintf(buf, cdev->online ? "1\n" : "0\n"); } +int ccw_device_is_orphan(struct ccw_device *cdev) +{ + return sch_is_pseudo_sch(to_subchannel(cdev->dev.parent)); +} + static void ccw_device_unregister(struct work_struct *work) { struct ccw_device_private *priv; @@ -310,10 +316,23 @@ static void ccw_device_remove_disconnected(struct ccw_device *cdev) { struct subchannel *sch; + unsigned long flags; /* * Forced offline in disconnected state means * 'throw away device'. */ + if (ccw_device_is_orphan(cdev)) { + /* Deregister ccw device. */ + spin_lock_irqsave(cdev->ccwlock, flags); + cdev->private->state = DEV_STATE_NOT_OPER; + spin_unlock_irqrestore(cdev->ccwlock, flags); + if (get_device(&cdev->dev)) { + PREPARE_WORK(&cdev->private->kick_work, + ccw_device_unregister); + queue_work(ccw_device_work, &cdev->private->kick_work); + } + return ; + } sch = to_subchannel(cdev->dev.parent); css_sch_device_unregister(sch); /* Reset intparm to zeroes. */ @@ -474,6 +493,8 @@ available_show (struct device *dev, struct device_attribute *attr, char *buf) struct ccw_device *cdev = to_ccwdev(dev); struct subchannel *sch; + if (ccw_device_is_orphan(cdev)) + return sprintf(buf, "no device\n"); switch (cdev->private->state) { case DEV_STATE_BOXED: return sprintf(buf, "boxed\n"); @@ -574,11 +595,10 @@ match_devno(struct device * dev, void * data) cdev = to_ccwdev(dev); if ((cdev->private->state == DEV_STATE_DISCONNECTED) && + !ccw_device_is_orphan(cdev) && ccw_dev_id_is_equal(&cdev->private->dev_id, &d->dev_id) && - (cdev != d->sibling)) { - cdev->private->state = DEV_STATE_NOT_OPER; + (cdev != d->sibling)) return 1; - } return 0; } @@ -595,6 +615,28 @@ static struct ccw_device * get_disc_ccwdev_by_dev_id(struct ccw_dev_id *dev_id, return dev ? to_ccwdev(dev) : NULL; } +static int match_orphan(struct device *dev, void *data) +{ + struct ccw_dev_id *dev_id; + struct ccw_device *cdev; + + dev_id = data; + cdev = to_ccwdev(dev); + return ccw_dev_id_is_equal(&cdev->private->dev_id, dev_id); +} + +static struct ccw_device * +get_orphaned_ccwdev_by_dev_id(struct channel_subsystem *css, + struct ccw_dev_id *dev_id) +{ + struct device *dev; + + dev = device_find_child(&css->pseudo_subchannel->dev, dev_id, + match_orphan); + + return dev ? to_ccwdev(dev) : NULL; +} + static void ccw_device_add_changed(struct work_struct *work) { @@ -614,64 +656,19 @@ ccw_device_add_changed(struct work_struct *work) } } -extern int css_get_ssd_info(struct subchannel *sch); - -void -ccw_device_do_unreg_rereg(struct work_struct *work) +void ccw_device_do_unreg_rereg(struct work_struct *work) { struct ccw_device_private *priv; struct ccw_device *cdev; struct subchannel *sch; - int need_rename; priv = container_of(work, struct ccw_device_private, kick_work); cdev = priv->cdev; sch = to_subchannel(cdev->dev.parent); - if (cdev->private->dev_id.devno != sch->schib.pmcw.dev) { - /* - * The device number has changed. This is usually only when - * a device has been detached under VM and then re-appeared - * on another subchannel because of a different attachment - * order than before. Ideally, we should should just switch - * subchannels, but unfortunately, this is not possible with - * the current implementation. - * Instead, we search for the old subchannel for this device - * number and deregister so there are no collisions with the - * newly registered ccw_device. - * FIXME: Find another solution so the block layer doesn't - * get possibly sick... - */ - struct ccw_device *other_cdev; - struct ccw_dev_id dev_id; - need_rename = 1; - dev_id.devno = sch->schib.pmcw.dev; - dev_id.ssid = sch->schid.ssid; - other_cdev = get_disc_ccwdev_by_dev_id(&dev_id, cdev); - if (other_cdev) { - struct subchannel *other_sch; - - other_sch = to_subchannel(other_cdev->dev.parent); - if (get_device(&other_sch->dev)) { - stsch(other_sch->schid, &other_sch->schib); - if (other_sch->schib.pmcw.dnv) { - other_sch->schib.pmcw.intparm = 0; - cio_modify(other_sch); - } - css_sch_device_unregister(other_sch); - } - } - /* Update ssd info here. */ - css_get_ssd_info(sch); - cdev->private->dev_id.devno = sch->schib.pmcw.dev; - } else - need_rename = 0; device_remove_files(&cdev->dev); if (test_and_clear_bit(1, &cdev->private->registered)) device_del(&cdev->dev); - if (need_rename) - snprintf (cdev->dev.bus_id, BUS_ID_SIZE, "0.%x.%04x", - sch->schid.ssid, sch->schib.pmcw.dev); PREPARE_WORK(&cdev->private->kick_work, ccw_device_add_changed); queue_work(ccw_device_work, &cdev->private->kick_work); @@ -736,6 +733,131 @@ static struct ccw_device * io_subchannel_create_ccwdev(struct subchannel *sch) return cdev; } +static int io_subchannel_recog(struct ccw_device *, struct subchannel *); + +static void sch_attach_device(struct subchannel *sch, + struct ccw_device *cdev) +{ + spin_lock_irq(sch->lock); + sch->dev.driver_data = cdev; + cdev->private->schid = sch->schid; + cdev->ccwlock = sch->lock; + device_trigger_reprobe(sch); + spin_unlock_irq(sch->lock); +} + +static void sch_attach_disconnected_device(struct subchannel *sch, + struct ccw_device *cdev) +{ + struct subchannel *other_sch; + int ret; + + other_sch = to_subchannel(get_device(cdev->dev.parent)); + ret = device_move(&cdev->dev, &sch->dev); + if (ret) { + CIO_MSG_EVENT(2, "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); + return; + } + other_sch->dev.driver_data = 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); +} + +static void sch_attach_orphaned_device(struct subchannel *sch, + struct ccw_device *cdev) +{ + int ret; + + /* Try to move the ccw device to its new subchannel. */ + 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); + return; + } + sch_attach_device(sch, cdev); +} + +static void sch_create_and_recog_new_device(struct subchannel *sch) +{ + struct ccw_device *cdev; + + /* Need to allocate a new ccw device. */ + cdev = io_subchannel_create_ccwdev(sch); + if (IS_ERR(cdev)) { + /* OK, we did everything we could... */ + css_sch_device_unregister(sch); + return; + } + spin_lock_irq(sch->lock); + sch->dev.driver_data = cdev; + spin_unlock_irq(sch->lock); + /* Start recognition for the new ccw device. */ + if (io_subchannel_recog(cdev, sch)) { + spin_lock_irq(sch->lock); + sch->dev.driver_data = NULL; + spin_unlock_irq(sch->lock); + if (cdev->dev.release) + cdev->dev.release(&cdev->dev); + css_sch_device_unregister(sch); + } +} + + +void ccw_device_move_to_orphanage(struct work_struct *work) +{ + struct ccw_device_private *priv; + struct ccw_device *cdev; + struct ccw_device *replacing_cdev; + struct subchannel *sch; + int ret; + struct channel_subsystem *css; + struct ccw_dev_id dev_id; + + priv = container_of(work, struct ccw_device_private, kick_work); + cdev = priv->cdev; + sch = to_subchannel(cdev->dev.parent); + css = to_css(sch->dev.parent); + dev_id.devno = sch->schib.pmcw.dev; + dev_id.ssid = sch->schid.ssid; + + /* + * Move the orphaned ccw device to the orphanage so the replacing + * ccw device can take its place on the subchannel. + */ + 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); + return; + } + cdev->ccwlock = css->pseudo_subchannel->lock; + /* + * Search for the replacing ccw device + * - among the disconnected devices + * - in the orphanage + */ + replacing_cdev = get_disc_ccwdev_by_dev_id(&dev_id, cdev); + if (replacing_cdev) { + sch_attach_disconnected_device(sch, replacing_cdev); + return; + } + replacing_cdev = get_orphaned_ccwdev_by_dev_id(css, &dev_id); + if (replacing_cdev) { + sch_attach_orphaned_device(sch, replacing_cdev); + return; + } + sch_create_and_recog_new_device(sch); +} + /* * Register recognized device. */ @@ -890,12 +1012,55 @@ io_subchannel_recog(struct ccw_device *cdev, struct subchannel *sch) return rc; } +static void ccw_device_move_to_sch(struct work_struct *work) +{ + struct ccw_device_private *priv; + int rc; + struct subchannel *sch; + struct ccw_device *cdev; + struct subchannel *former_parent; + + 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)); + mutex_lock(&sch->reg_mutex); + /* Try to move the ccw device to its new subchannel. */ + rc = device_move(&cdev->dev, &sch->dev); + mutex_unlock(&sch->reg_mutex); + if (rc) { + CIO_MSG_EVENT(2, "Moving device 0.%x.%04x to subchannel " + "0.%x.%04x failed (ret=%d)!\n", + cdev->private->dev_id.ssid, + cdev->private->dev_id.devno, sch->schid.ssid, + sch->schid.sch_no, rc); + css_sch_device_unregister(sch); + goto out; + } + if (former_parent) { + spin_lock_irq(former_parent->lock); + former_parent->dev.driver_data = 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); + } + sch_attach_device(sch, cdev); +out: + if (former_parent) + put_device(&former_parent->dev); + put_device(&cdev->dev); +} + static int io_subchannel_probe (struct subchannel *sch) { struct ccw_device *cdev; int rc; unsigned long flags; + struct ccw_dev_id dev_id; if (sch->dev.driver_data) { /* @@ -918,6 +1083,28 @@ io_subchannel_probe (struct subchannel *sch) get_device(&cdev->dev); return 0; } + /* + * 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), + &dev_id); + if (cdev) { + /* + * Schedule moving the device until when we have a registered + * subchannel to move to and succeed the probe. We can + * unregister later again, when the probe is through. + */ + cdev->private->sch = sch; + PREPARE_WORK(&cdev->private->kick_work, + ccw_device_move_to_sch); + queue_work(slow_path_wq, &cdev->private->kick_work); + return 0; + } cdev = io_subchannel_create_ccwdev(sch); if (IS_ERR(cdev)) return PTR_ERR(cdev); diff --git a/drivers/s390/cio/device.h b/drivers/s390/cio/device.h index d5fe95e04cfe..29db6341d632 100644 --- a/drivers/s390/cio/device.h +++ b/drivers/s390/cio/device.h @@ -80,6 +80,8 @@ int ccw_device_cancel_halt_clear(struct ccw_device *); void ccw_device_do_unreg_rereg(struct work_struct *); void ccw_device_call_sch_unregister(struct work_struct *); +void ccw_device_move_to_orphanage(struct work_struct *); +int ccw_device_is_orphan(struct ccw_device *); int ccw_device_recognition(struct ccw_device *); int ccw_device_online(struct ccw_device *); diff --git a/drivers/s390/cio/device_fsm.c b/drivers/s390/cio/device_fsm.c index a487fb0e7d3d..eed14572fc3b 100644 --- a/drivers/s390/cio/device_fsm.c +++ b/drivers/s390/cio/device_fsm.c @@ -186,13 +186,12 @@ ccw_device_handle_oper(struct ccw_device *cdev) /* * Check if cu type and device type still match. If * not, it is certainly another device and we have to - * de- and re-register. Also check here for non-matching devno. + * de- and re-register. */ if (cdev->id.cu_type != cdev->private->senseid.cu_type || cdev->id.cu_model != cdev->private->senseid.cu_model || cdev->id.dev_type != cdev->private->senseid.dev_type || - cdev->id.dev_model != cdev->private->senseid.dev_model || - cdev->private->dev_id.devno != sch->schib.pmcw.dev) { + cdev->id.dev_model != cdev->private->senseid.dev_model) { PREPARE_WORK(&cdev->private->kick_work, ccw_device_do_unreg_rereg); queue_work(ccw_device_work, &cdev->private->kick_work); @@ -676,6 +675,10 @@ ccw_device_offline(struct ccw_device *cdev) { struct subchannel *sch; + if (ccw_device_is_orphan(cdev)) { + ccw_device_done(cdev, DEV_STATE_OFFLINE); + return 0; + } sch = to_subchannel(cdev->dev.parent); if (stsch(sch->schid, &sch->schib) || !sch->schib.pmcw.dnv) return -ENODEV; @@ -1121,7 +1124,13 @@ device_trigger_reprobe(struct subchannel *sch) sch->schib.pmcw.mp = 1; sch->schib.pmcw.intparm = (__u32)(unsigned long)sch; /* We should also udate ssd info, but this has to wait. */ - ccw_device_start_id(cdev, 0); + /* Check if this is another device which appeared on the same sch. */ + if (sch->schib.pmcw.dev != cdev->private->dev_id.devno) { + PREPARE_WORK(&cdev->private->kick_work, + ccw_device_move_to_orphanage); + queue_work(ccw_device_work, &cdev->private->kick_work); + } else + ccw_device_start_id(cdev, 0); } static void