diff options
Diffstat (limited to 'drivers/s390/cio/css.c')
| -rw-r--r-- | drivers/s390/cio/css.c | 1404 |
1 files changed, 1404 insertions, 0 deletions
diff --git a/drivers/s390/cio/css.c b/drivers/s390/cio/css.c new file mode 100644 index 000000000..10e8b3b15 --- /dev/null +++ b/drivers/s390/cio/css.c @@ -0,0 +1,1404 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * driver for channel subsystem + * + * Copyright IBM Corp. 2002, 2010 + * + * Author(s): Arnd Bergmann (arndb@de.ibm.com) + * Cornelia Huck (cornelia.huck@de.ibm.com) + */ + +#define KMSG_COMPONENT "cio" +#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt + +#include <linux/export.h> +#include <linux/init.h> +#include <linux/device.h> +#include <linux/slab.h> +#include <linux/errno.h> +#include <linux/list.h> +#include <linux/reboot.h> +#include <linux/suspend.h> +#include <linux/proc_fs.h> +#include <asm/isc.h> +#include <asm/crw.h> + +#include "css.h" +#include "cio.h" +#include "blacklist.h" +#include "cio_debug.h" +#include "ioasm.h" +#include "chsc.h" +#include "device.h" +#include "idset.h" +#include "chp.h" + +int css_init_done = 0; +int max_ssid; + +#define MAX_CSS_IDX 0 +struct channel_subsystem *channel_subsystems[MAX_CSS_IDX + 1]; +static struct bus_type css_bus_type; + +int +for_each_subchannel(int(*fn)(struct subchannel_id, void *), void *data) +{ + struct subchannel_id schid; + int ret; + + init_subchannel_id(&schid); + do { + do { + ret = fn(schid, data); + if (ret) + break; + } while (schid.sch_no++ < __MAX_SUBCHANNEL); + schid.sch_no = 0; + } while (schid.ssid++ < max_ssid); + return ret; +} + +struct cb_data { + void *data; + struct idset *set; + int (*fn_known_sch)(struct subchannel *, void *); + int (*fn_unknown_sch)(struct subchannel_id, void *); +}; + +static int call_fn_known_sch(struct device *dev, void *data) +{ + struct subchannel *sch = to_subchannel(dev); + struct cb_data *cb = data; + int rc = 0; + + if (cb->set) + idset_sch_del(cb->set, sch->schid); + if (cb->fn_known_sch) + rc = cb->fn_known_sch(sch, cb->data); + return rc; +} + +static int call_fn_unknown_sch(struct subchannel_id schid, void *data) +{ + struct cb_data *cb = data; + int rc = 0; + + if (idset_sch_contains(cb->set, schid)) + rc = cb->fn_unknown_sch(schid, cb->data); + return rc; +} + +static int call_fn_all_sch(struct subchannel_id schid, void *data) +{ + struct cb_data *cb = data; + struct subchannel *sch; + int rc = 0; + + sch = get_subchannel_by_schid(schid); + if (sch) { + if (cb->fn_known_sch) + rc = cb->fn_known_sch(sch, cb->data); + put_device(&sch->dev); + } else { + if (cb->fn_unknown_sch) + rc = cb->fn_unknown_sch(schid, cb->data); + } + + return rc; +} + +int for_each_subchannel_staged(int (*fn_known)(struct subchannel *, void *), + int (*fn_unknown)(struct subchannel_id, + void *), void *data) +{ + struct cb_data cb; + int rc; + + cb.data = data; + cb.fn_known_sch = fn_known; + cb.fn_unknown_sch = fn_unknown; + + if (fn_known && !fn_unknown) { + /* Skip idset allocation in case of known-only loop. */ + cb.set = NULL; + return bus_for_each_dev(&css_bus_type, NULL, &cb, + call_fn_known_sch); + } + + cb.set = idset_sch_new(); + if (!cb.set) + /* fall back to brute force scanning in case of oom */ + return for_each_subchannel(call_fn_all_sch, &cb); + + idset_fill(cb.set); + + /* Process registered subchannels. */ + rc = bus_for_each_dev(&css_bus_type, NULL, &cb, call_fn_known_sch); + if (rc) + goto out; + /* Process unregistered subchannels. */ + if (fn_unknown) + rc = for_each_subchannel(call_fn_unknown_sch, &cb); +out: + idset_free(cb.set); + + return rc; +} + +static void css_sch_todo(struct work_struct *work); + +static int css_sch_create_locks(struct subchannel *sch) +{ + sch->lock = kmalloc(sizeof(*sch->lock), GFP_KERNEL); + if (!sch->lock) + return -ENOMEM; + + spin_lock_init(sch->lock); + mutex_init(&sch->reg_mutex); + + return 0; +} + +static void css_subchannel_release(struct device *dev) +{ + struct subchannel *sch = to_subchannel(dev); + + sch->config.intparm = 0; + cio_commit_config(sch); + kfree(sch->lock); + kfree(sch); +} + +static int css_validate_subchannel(struct subchannel_id schid, + struct schib *schib) +{ + int err; + + switch (schib->pmcw.st) { + case SUBCHANNEL_TYPE_IO: + case SUBCHANNEL_TYPE_MSG: + if (!css_sch_is_valid(schib)) + err = -ENODEV; + else if (is_blacklisted(schid.ssid, schib->pmcw.dev)) { + CIO_MSG_EVENT(6, "Blacklisted device detected " + "at devno %04X, subchannel set %x\n", + schib->pmcw.dev, schid.ssid); + err = -ENODEV; + } else + err = 0; + break; + default: + err = 0; + } + if (err) + goto out; + + CIO_MSG_EVENT(4, "Subchannel 0.%x.%04x reports subchannel type %04X\n", + schid.ssid, schid.sch_no, schib->pmcw.st); +out: + return err; +} + +struct subchannel *css_alloc_subchannel(struct subchannel_id schid, + struct schib *schib) +{ + struct subchannel *sch; + int ret; + + ret = css_validate_subchannel(schid, schib); + if (ret < 0) + return ERR_PTR(ret); + + sch = kzalloc(sizeof(*sch), GFP_KERNEL | GFP_DMA); + if (!sch) + return ERR_PTR(-ENOMEM); + + sch->schid = schid; + sch->schib = *schib; + sch->st = schib->pmcw.st; + + ret = css_sch_create_locks(sch); + if (ret) + goto err; + + INIT_WORK(&sch->todo_work, css_sch_todo); + sch->dev.release = &css_subchannel_release; + device_initialize(&sch->dev); + return sch; + +err: + kfree(sch); + return ERR_PTR(ret); +} + +static int css_sch_device_register(struct subchannel *sch) +{ + int ret; + + mutex_lock(&sch->reg_mutex); + dev_set_name(&sch->dev, "0.%x.%04x", sch->schid.ssid, + sch->schid.sch_no); + ret = device_add(&sch->dev); + mutex_unlock(&sch->reg_mutex); + return ret; +} + +/** + * css_sch_device_unregister - unregister a subchannel + * @sch: subchannel to be unregistered + */ +void css_sch_device_unregister(struct subchannel *sch) +{ + mutex_lock(&sch->reg_mutex); + if (device_is_registered(&sch->dev)) + device_unregister(&sch->dev); + mutex_unlock(&sch->reg_mutex); +} +EXPORT_SYMBOL_GPL(css_sch_device_unregister); + +static void ssd_from_pmcw(struct chsc_ssd_info *ssd, struct pmcw *pmcw) +{ + int i; + int mask; + + memset(ssd, 0, sizeof(struct chsc_ssd_info)); + ssd->path_mask = pmcw->pim; + for (i = 0; i < 8; i++) { + mask = 0x80 >> i; + if (pmcw->pim & mask) { + chp_id_init(&ssd->chpid[i]); + ssd->chpid[i].id = pmcw->chpid[i]; + } + } +} + +static void ssd_register_chpids(struct chsc_ssd_info *ssd) +{ + int i; + int mask; + + for (i = 0; i < 8; i++) { + mask = 0x80 >> i; + if (ssd->path_mask & mask) + chp_new(ssd->chpid[i]); + } +} + +void css_update_ssd_info(struct subchannel *sch) +{ + int ret; + + ret = chsc_get_ssd_info(sch->schid, &sch->ssd_info); + if (ret) + ssd_from_pmcw(&sch->ssd_info, &sch->schib.pmcw); + + ssd_register_chpids(&sch->ssd_info); +} + +static ssize_t type_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct subchannel *sch = to_subchannel(dev); + + return sprintf(buf, "%01x\n", sch->st); +} + +static DEVICE_ATTR_RO(type); + +static ssize_t modalias_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct subchannel *sch = to_subchannel(dev); + + return sprintf(buf, "css:t%01X\n", sch->st); +} + +static DEVICE_ATTR_RO(modalias); + +static struct attribute *subch_attrs[] = { + &dev_attr_type.attr, + &dev_attr_modalias.attr, + NULL, +}; + +static struct attribute_group subch_attr_group = { + .attrs = subch_attrs, +}; + +static const struct attribute_group *default_subch_attr_groups[] = { + &subch_attr_group, + NULL, +}; + +static ssize_t chpids_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct subchannel *sch = to_subchannel(dev); + struct chsc_ssd_info *ssd = &sch->ssd_info; + ssize_t ret = 0; + int mask; + int chp; + + for (chp = 0; chp < 8; chp++) { + mask = 0x80 >> chp; + if (ssd->path_mask & mask) + ret += sprintf(buf + ret, "%02x ", ssd->chpid[chp].id); + else + ret += sprintf(buf + ret, "00 "); + } + ret += sprintf(buf + ret, "\n"); + return ret; +} +static DEVICE_ATTR_RO(chpids); + +static ssize_t pimpampom_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct subchannel *sch = to_subchannel(dev); + struct pmcw *pmcw = &sch->schib.pmcw; + + return sprintf(buf, "%02x %02x %02x\n", + pmcw->pim, pmcw->pam, pmcw->pom); +} +static DEVICE_ATTR_RO(pimpampom); + +static ssize_t dev_busid_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct subchannel *sch = to_subchannel(dev); + struct pmcw *pmcw = &sch->schib.pmcw; + + if ((pmcw->st == SUBCHANNEL_TYPE_IO && pmcw->dnv) || + (pmcw->st == SUBCHANNEL_TYPE_MSG && pmcw->w)) + return sysfs_emit(buf, "0.%x.%04x\n", sch->schid.ssid, + pmcw->dev); + else + return sysfs_emit(buf, "none\n"); +} +static DEVICE_ATTR_RO(dev_busid); + +static struct attribute *io_subchannel_type_attrs[] = { + &dev_attr_chpids.attr, + &dev_attr_pimpampom.attr, + &dev_attr_dev_busid.attr, + NULL, +}; +ATTRIBUTE_GROUPS(io_subchannel_type); + +static const struct device_type io_subchannel_type = { + .groups = io_subchannel_type_groups, +}; + +int css_register_subchannel(struct subchannel *sch) +{ + int ret; + + /* Initialize the subchannel structure */ + sch->dev.parent = &channel_subsystems[0]->device; + sch->dev.bus = &css_bus_type; + sch->dev.groups = default_subch_attr_groups; + + if (sch->st == SUBCHANNEL_TYPE_IO) + sch->dev.type = &io_subchannel_type; + + /* + * We don't want to generate uevents for I/O subchannels that don't + * have a working ccw device behind them since they will be + * unregistered before they can be used anyway, so we delay the add + * uevent until after device recognition was successful. + * Note that we suppress the uevent for all subchannel types; + * the subchannel driver can decide itself when it wants to inform + * userspace of its existence. + */ + dev_set_uevent_suppress(&sch->dev, 1); + css_update_ssd_info(sch); + /* make it known to the system */ + ret = css_sch_device_register(sch); + if (ret) { + CIO_MSG_EVENT(0, "Could not register sch 0.%x.%04x: %d\n", + sch->schid.ssid, sch->schid.sch_no, ret); + return ret; + } + if (!sch->driver) { + /* + * No driver matched. Generate the uevent now so that + * a fitting driver module may be loaded based on the + * modalias. + */ + dev_set_uevent_suppress(&sch->dev, 0); + kobject_uevent(&sch->dev.kobj, KOBJ_ADD); + } + return ret; +} + +static int css_probe_device(struct subchannel_id schid, struct schib *schib) +{ + struct subchannel *sch; + int ret; + + sch = css_alloc_subchannel(schid, schib); + if (IS_ERR(sch)) + return PTR_ERR(sch); + + ret = css_register_subchannel(sch); + if (ret) + put_device(&sch->dev); + + return ret; +} + +static int +check_subchannel(struct device * dev, void * data) +{ + struct subchannel *sch; + struct subchannel_id *schid = data; + + sch = to_subchannel(dev); + return schid_equal(&sch->schid, schid); +} + +struct subchannel * +get_subchannel_by_schid(struct subchannel_id schid) +{ + struct device *dev; + + dev = bus_find_device(&css_bus_type, NULL, + &schid, check_subchannel); + + return dev ? to_subchannel(dev) : NULL; +} + +/** + * css_sch_is_valid() - check if a subchannel is valid + * @schib: subchannel information block for the subchannel + */ +int css_sch_is_valid(struct schib *schib) +{ + if ((schib->pmcw.st == SUBCHANNEL_TYPE_IO) && !schib->pmcw.dnv) + return 0; + if ((schib->pmcw.st == SUBCHANNEL_TYPE_MSG) && !schib->pmcw.w) + return 0; + return 1; +} +EXPORT_SYMBOL_GPL(css_sch_is_valid); + +static int css_evaluate_new_subchannel(struct subchannel_id schid, int slow) +{ + struct schib schib; + int ccode; + + if (!slow) { + /* Will be done on the slow path. */ + return -EAGAIN; + } + /* + * The first subchannel that is not-operational (ccode==3) + * indicates that there aren't any more devices available. + * If stsch gets an exception, it means the current subchannel set + * is not valid. + */ + ccode = stsch(schid, &schib); + if (ccode) + return (ccode == 3) ? -ENXIO : ccode; + + return css_probe_device(schid, &schib); +} + +static int css_evaluate_known_subchannel(struct subchannel *sch, int slow) +{ + int ret = 0; + + if (sch->driver) { + if (sch->driver->sch_event) + ret = sch->driver->sch_event(sch, slow); + else + dev_dbg(&sch->dev, + "Got subchannel machine check but " + "no sch_event handler provided.\n"); + } + if (ret != 0 && ret != -EAGAIN) { + CIO_MSG_EVENT(2, "eval: sch 0.%x.%04x, rc=%d\n", + sch->schid.ssid, sch->schid.sch_no, ret); + } + return ret; +} + +static void css_evaluate_subchannel(struct subchannel_id schid, int slow) +{ + struct subchannel *sch; + int ret; + + sch = get_subchannel_by_schid(schid); + if (sch) { + ret = css_evaluate_known_subchannel(sch, slow); + put_device(&sch->dev); + } else + ret = css_evaluate_new_subchannel(schid, slow); + if (ret == -EAGAIN) + css_schedule_eval(schid); +} + +/** + * css_sched_sch_todo - schedule a subchannel operation + * @sch: subchannel + * @todo: todo + * + * Schedule the operation identified by @todo to be performed on the slow path + * workqueue. Do nothing if another operation with higher priority is already + * scheduled. Needs to be called with subchannel lock held. + */ +void css_sched_sch_todo(struct subchannel *sch, enum sch_todo todo) +{ + CIO_MSG_EVENT(4, "sch_todo: sched sch=0.%x.%04x todo=%d\n", + sch->schid.ssid, sch->schid.sch_no, todo); + if (sch->todo >= todo) + return; + /* Get workqueue ref. */ + if (!get_device(&sch->dev)) + return; + sch->todo = todo; + if (!queue_work(cio_work_q, &sch->todo_work)) { + /* Already queued, release workqueue ref. */ + put_device(&sch->dev); + } +} +EXPORT_SYMBOL_GPL(css_sched_sch_todo); + +static void css_sch_todo(struct work_struct *work) +{ + struct subchannel *sch; + enum sch_todo todo; + int ret; + + sch = container_of(work, struct subchannel, todo_work); + /* Find out todo. */ + spin_lock_irq(sch->lock); + todo = sch->todo; + CIO_MSG_EVENT(4, "sch_todo: sch=0.%x.%04x, todo=%d\n", sch->schid.ssid, + sch->schid.sch_no, todo); + sch->todo = SCH_TODO_NOTHING; + spin_unlock_irq(sch->lock); + /* Perform todo. */ + switch (todo) { + case SCH_TODO_NOTHING: + break; + case SCH_TODO_EVAL: + ret = css_evaluate_known_subchannel(sch, 1); + if (ret == -EAGAIN) { + spin_lock_irq(sch->lock); + css_sched_sch_todo(sch, todo); + spin_unlock_irq(sch->lock); + } + break; + case SCH_TODO_UNREG: + css_sch_device_unregister(sch); + break; + } + /* Release workqueue ref. */ + put_device(&sch->dev); +} + +static struct idset *slow_subchannel_set; +static spinlock_t slow_subchannel_lock; +static wait_queue_head_t css_eval_wq; +static atomic_t css_eval_scheduled; + +static int __init slow_subchannel_init(void) +{ + spin_lock_init(&slow_subchannel_lock); + atomic_set(&css_eval_scheduled, 0); + init_waitqueue_head(&css_eval_wq); + slow_subchannel_set = idset_sch_new(); + if (!slow_subchannel_set) { + CIO_MSG_EVENT(0, "could not allocate slow subchannel set\n"); + return -ENOMEM; + } + return 0; +} + +static int slow_eval_known_fn(struct subchannel *sch, void *data) +{ + int eval; + int rc; + + spin_lock_irq(&slow_subchannel_lock); + eval = idset_sch_contains(slow_subchannel_set, sch->schid); + idset_sch_del(slow_subchannel_set, sch->schid); + spin_unlock_irq(&slow_subchannel_lock); + if (eval) { + rc = css_evaluate_known_subchannel(sch, 1); + if (rc == -EAGAIN) + css_schedule_eval(sch->schid); + /* + * The loop might take long time for platforms with lots of + * known devices. Allow scheduling here. + */ + cond_resched(); + } + return 0; +} + +static int slow_eval_unknown_fn(struct subchannel_id schid, void *data) +{ + int eval; + int rc = 0; + + spin_lock_irq(&slow_subchannel_lock); + eval = idset_sch_contains(slow_subchannel_set, schid); + idset_sch_del(slow_subchannel_set, schid); + spin_unlock_irq(&slow_subchannel_lock); + if (eval) { + rc = css_evaluate_new_subchannel(schid, 1); + switch (rc) { + case -EAGAIN: + css_schedule_eval(schid); + rc = 0; + break; + case -ENXIO: + case -ENOMEM: + case -EIO: + /* These should abort looping */ + spin_lock_irq(&slow_subchannel_lock); + idset_sch_del_subseq(slow_subchannel_set, schid); + spin_unlock_irq(&slow_subchannel_lock); + break; + default: + rc = 0; + } + /* Allow scheduling here since the containing loop might + * take a while. */ + cond_resched(); + } + return rc; +} + +static void css_slow_path_func(struct work_struct *unused) +{ + unsigned long flags; + + CIO_TRACE_EVENT(4, "slowpath"); + for_each_subchannel_staged(slow_eval_known_fn, slow_eval_unknown_fn, + NULL); + spin_lock_irqsave(&slow_subchannel_lock, flags); + if (idset_is_empty(slow_subchannel_set)) { + atomic_set(&css_eval_scheduled, 0); + wake_up(&css_eval_wq); + } + spin_unlock_irqrestore(&slow_subchannel_lock, flags); +} + +static DECLARE_DELAYED_WORK(slow_path_work, css_slow_path_func); +struct workqueue_struct *cio_work_q; + +void css_schedule_eval(struct subchannel_id schid) +{ + unsigned long flags; + + spin_lock_irqsave(&slow_subchannel_lock, flags); + idset_sch_add(slow_subchannel_set, schid); + atomic_set(&css_eval_scheduled, 1); + queue_delayed_work(cio_work_q, &slow_path_work, 0); + spin_unlock_irqrestore(&slow_subchannel_lock, flags); +} + +void css_schedule_eval_all(void) +{ + unsigned long flags; + + spin_lock_irqsave(&slow_subchannel_lock, flags); + idset_fill(slow_subchannel_set); + atomic_set(&css_eval_scheduled, 1); + queue_delayed_work(cio_work_q, &slow_path_work, 0); + spin_unlock_irqrestore(&slow_subchannel_lock, flags); +} + +static int __unset_registered(struct device *dev, void *data) +{ + struct idset *set = data; + struct subchannel *sch = to_subchannel(dev); + + idset_sch_del(set, sch->schid); + return 0; +} + +void css_schedule_eval_all_unreg(unsigned long delay) +{ + unsigned long flags; + struct idset *unreg_set; + + /* Find unregistered subchannels. */ + unreg_set = idset_sch_new(); + if (!unreg_set) { + /* Fallback. */ + css_schedule_eval_all(); + return; + } + idset_fill(unreg_set); + bus_for_each_dev(&css_bus_type, NULL, unreg_set, __unset_registered); + /* Apply to slow_subchannel_set. */ + spin_lock_irqsave(&slow_subchannel_lock, flags); + idset_add_set(slow_subchannel_set, unreg_set); + atomic_set(&css_eval_scheduled, 1); + queue_delayed_work(cio_work_q, &slow_path_work, delay); + spin_unlock_irqrestore(&slow_subchannel_lock, flags); + idset_free(unreg_set); +} + +void css_wait_for_slow_path(void) +{ + flush_workqueue(cio_work_q); +} + +/* Schedule reprobing of all unregistered subchannels. */ +void css_schedule_reprobe(void) +{ + /* Schedule with a delay to allow merging of subsequent calls. */ + css_schedule_eval_all_unreg(1 * HZ); +} +EXPORT_SYMBOL_GPL(css_schedule_reprobe); + +/* + * Called from the machine check handler for subchannel report words. + */ +static void css_process_crw(struct crw *crw0, struct crw *crw1, int overflow) +{ + struct subchannel_id mchk_schid; + struct subchannel *sch; + + if (overflow) { + css_schedule_eval_all(); + return; + } + CIO_CRW_EVENT(2, "CRW0 reports slct=%d, oflw=%d, " + "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n", + crw0->slct, crw0->oflw, crw0->chn, crw0->rsc, crw0->anc, + crw0->erc, crw0->rsid); + if (crw1) + CIO_CRW_EVENT(2, "CRW1 reports slct=%d, oflw=%d, " + "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n", + crw1->slct, crw1->oflw, crw1->chn, crw1->rsc, + crw1->anc, crw1->erc, crw1->rsid); + init_subchannel_id(&mchk_schid); + mchk_schid.sch_no = crw0->rsid; + if (crw1) + mchk_schid.ssid = (crw1->rsid >> 4) & 3; + + if (crw0->erc == CRW_ERC_PMOD) { + sch = get_subchannel_by_schid(mchk_schid); + if (sch) { + css_update_ssd_info(sch); + put_device(&sch->dev); + } + } + /* + * Since we are always presented with IPI in the CRW, we have to + * use stsch() to find out if the subchannel in question has come + * or gone. + */ + css_evaluate_subchannel(mchk_schid, 0); +} + +static void __init +css_generate_pgid(struct channel_subsystem *css, u32 tod_high) +{ + struct cpuid cpu_id; + + if (css_general_characteristics.mcss) { + css->global_pgid.pgid_high.ext_cssid.version = 0x80; + css->global_pgid.pgid_high.ext_cssid.cssid = + (css->cssid < 0) ? 0 : css->cssid; + } else { + css->global_pgid.pgid_high.cpu_addr = stap(); + } + get_cpu_id(&cpu_id); + css->global_pgid.cpu_id = cpu_id.ident; + css->global_pgid.cpu_model = cpu_id.machine; + css->global_pgid.tod_high = tod_high; +} + +static void channel_subsystem_release(struct device *dev) +{ + struct channel_subsystem *css = to_css(dev); + + mutex_destroy(&css->mutex); + kfree(css); +} + +static ssize_t real_cssid_show(struct device *dev, struct device_attribute *a, + char *buf) +{ + struct channel_subsystem *css = to_css(dev); + + if (css->cssid < 0) + return -EINVAL; + + return sprintf(buf, "%x\n", css->cssid); +} +static DEVICE_ATTR_RO(real_cssid); + +static ssize_t cm_enable_show(struct device *dev, struct device_attribute *a, + char *buf) +{ + struct channel_subsystem *css = to_css(dev); + int ret; + + mutex_lock(&css->mutex); + ret = sprintf(buf, "%x\n", css->cm_enabled); + mutex_unlock(&css->mutex); + return ret; +} + +static ssize_t cm_enable_store(struct device *dev, struct device_attribute *a, + const char *buf, size_t count) +{ + struct channel_subsystem *css = to_css(dev); + unsigned long val; + int ret; + + ret = kstrtoul(buf, 16, &val); + if (ret) + return ret; + mutex_lock(&css->mutex); + switch (val) { + case 0: + ret = css->cm_enabled ? chsc_secm(css, 0) : 0; + break; + case 1: + ret = css->cm_enabled ? 0 : chsc_secm(css, 1); + break; + default: + ret = -EINVAL; + } + mutex_unlock(&css->mutex); + return ret < 0 ? ret : count; +} +static DEVICE_ATTR_RW(cm_enable); + +static umode_t cm_enable_mode(struct kobject *kobj, struct attribute *attr, + int index) +{ + return css_chsc_characteristics.secm ? attr->mode : 0; +} + +static struct attribute *cssdev_attrs[] = { + &dev_attr_real_cssid.attr, + NULL, +}; + +static struct attribute_group cssdev_attr_group = { + .attrs = cssdev_attrs, +}; + +static struct attribute *cssdev_cm_attrs[] = { + &dev_attr_cm_enable.attr, + NULL, +}; + +static struct attribute_group cssdev_cm_attr_group = { + .attrs = cssdev_cm_attrs, + .is_visible = cm_enable_mode, +}; + +static const struct attribute_group *cssdev_attr_groups[] = { + &cssdev_attr_group, + &cssdev_cm_attr_group, + NULL, +}; + +static int __init setup_css(int nr) +{ + struct channel_subsystem *css; + int ret; + + css = kzalloc(sizeof(*css), GFP_KERNEL); + if (!css) + return -ENOMEM; + + channel_subsystems[nr] = css; + dev_set_name(&css->device, "css%x", nr); + css->device.groups = cssdev_attr_groups; + css->device.release = channel_subsystem_release; + + mutex_init(&css->mutex); + css->cssid = chsc_get_cssid(nr); + css_generate_pgid(css, (u32) (get_tod_clock() >> 32)); + + ret = device_register(&css->device); + if (ret) { + put_device(&css->device); + goto out_err; + } + + css->pseudo_subchannel = kzalloc(sizeof(*css->pseudo_subchannel), + GFP_KERNEL); + if (!css->pseudo_subchannel) { + device_unregister(&css->device); + ret = -ENOMEM; + goto out_err; + } + + css->pseudo_subchannel->dev.parent = &css->device; + css->pseudo_subchannel->dev.release = css_subchannel_release; + mutex_init(&css->pseudo_subchannel->reg_mutex); + ret = css_sch_create_locks(css->pseudo_subchannel); + if (ret) { + kfree(css->pseudo_subchannel); + device_unregister(&css->device); + goto out_err; + } + + dev_set_name(&css->pseudo_subchannel->dev, "defunct"); + ret = device_register(&css->pseudo_subchannel->dev); + if (ret) { + put_device(&css->pseudo_subchannel->dev); + device_unregister(&css->device); + goto out_err; + } + + return ret; +out_err: + channel_subsystems[nr] = NULL; + return ret; +} + +static int css_reboot_event(struct notifier_block *this, + unsigned long event, + void *ptr) +{ + struct channel_subsystem *css; + int ret; + + ret = NOTIFY_DONE; + for_each_css(css) { + mutex_lock(&css->mutex); + if (css->cm_enabled) + if (chsc_secm(css, 0)) + ret = NOTIFY_BAD; + mutex_unlock(&css->mutex); + } + + return ret; +} + +static struct notifier_block css_reboot_notifier = { + .notifier_call = css_reboot_event, +}; + +/* + * Since the css devices are neither on a bus nor have a class + * nor have a special device type, we cannot stop/restart channel + * path measurements via the normal suspend/resume callbacks, but have + * to use notifiers. + */ +static int css_power_event(struct notifier_block *this, unsigned long event, + void *ptr) +{ + struct channel_subsystem *css; + int ret; + + switch (event) { + case PM_HIBERNATION_PREPARE: + case PM_SUSPEND_PREPARE: + ret = NOTIFY_DONE; + for_each_css(css) { + mutex_lock(&css->mutex); + if (!css->cm_enabled) { + mutex_unlock(&css->mutex); + continue; + } + ret = __chsc_do_secm(css, 0); + ret = notifier_from_errno(ret); + mutex_unlock(&css->mutex); + } + break; + case PM_POST_HIBERNATION: + case PM_POST_SUSPEND: + ret = NOTIFY_DONE; + for_each_css(css) { + mutex_lock(&css->mutex); + if (!css->cm_enabled) { + mutex_unlock(&css->mutex); + continue; + } + ret = __chsc_do_secm(css, 1); + ret = notifier_from_errno(ret); + mutex_unlock(&css->mutex); + } + /* search for subchannels, which appeared during hibernation */ + css_schedule_reprobe(); + break; + default: + ret = NOTIFY_DONE; + } + return ret; + +} +static struct notifier_block css_power_notifier = { + .notifier_call = css_power_event, +}; + +/* + * Now that the driver core is running, we can setup our channel subsystem. + * The struct subchannel's are created during probing. + */ +static int __init css_bus_init(void) +{ + int ret, i; + + ret = chsc_init(); + if (ret) + return ret; + + chsc_determine_css_characteristics(); + /* Try to enable MSS. */ + ret = chsc_enable_facility(CHSC_SDA_OC_MSS); + if (ret) + max_ssid = 0; + else /* Success. */ + max_ssid = __MAX_SSID; + + ret = slow_subchannel_init(); + if (ret) + goto out; + + ret = crw_register_handler(CRW_RSC_SCH, css_process_crw); + if (ret) + goto out; + + if ((ret = bus_register(&css_bus_type))) + goto out; + + /* Setup css structure. */ + for (i = 0; i <= MAX_CSS_IDX; i++) { + ret = setup_css(i); + if (ret) + goto out_unregister; + } + ret = register_reboot_notifier(&css_reboot_notifier); + if (ret) + goto out_unregister; + ret = register_pm_notifier(&css_power_notifier); + if (ret) { + unregister_reboot_notifier(&css_reboot_notifier); + goto out_unregister; + } + css_init_done = 1; + + /* Enable default isc for I/O subchannels. */ + isc_register(IO_SCH_ISC); + + return 0; +out_unregister: + while (i-- > 0) { + struct channel_subsystem *css = channel_subsystems[i]; + device_unregister(&css->pseudo_subchannel->dev); + device_unregister(&css->device); + } + bus_unregister(&css_bus_type); +out: + crw_unregister_handler(CRW_RSC_SCH); + idset_free(slow_subchannel_set); + chsc_init_cleanup(); + pr_alert("The CSS device driver initialization failed with " + "errno=%d\n", ret); + return ret; +} + +static void __init css_bus_cleanup(void) +{ + struct channel_subsystem *css; + + for_each_css(css) { + device_unregister(&css->pseudo_subchannel->dev); + device_unregister(&css->device); + } + bus_unregister(&css_bus_type); + crw_unregister_handler(CRW_RSC_SCH); + idset_free(slow_subchannel_set); + chsc_init_cleanup(); + isc_unregister(IO_SCH_ISC); +} + +static int __init channel_subsystem_init(void) +{ + int ret; + + ret = css_bus_init(); + if (ret) + return ret; + cio_work_q = create_singlethread_workqueue("cio"); + if (!cio_work_q) { + ret = -ENOMEM; + goto out_bus; + } + ret = io_subchannel_init(); + if (ret) + goto out_wq; + + /* Register subchannels which are already in use. */ + cio_register_early_subchannels(); + /* Start initial subchannel evaluation. */ + css_schedule_eval_all(); + + return ret; +out_wq: + destroy_workqueue(cio_work_q); +out_bus: + css_bus_cleanup(); + return ret; +} +subsys_initcall(channel_subsystem_init); + +static int css_settle(struct device_driver *drv, void *unused) +{ + struct css_driver *cssdrv = to_cssdriver(drv); + + if (cssdrv->settle) + return cssdrv->settle(); + return 0; +} + +int css_complete_work(void) +{ + int ret; + + /* Wait for the evaluation of subchannels to finish. */ + ret = wait_event_interruptible(css_eval_wq, + atomic_read(&css_eval_scheduled) == 0); + if (ret) + return -EINTR; + flush_workqueue(cio_work_q); + /* Wait for the subchannel type specific initialization to finish */ + return bus_for_each_drv(&css_bus_type, NULL, NULL, css_settle); +} + + +/* + * Wait for the initialization of devices to finish, to make sure we are + * done with our setup if the search for the root device starts. + */ +static int __init channel_subsystem_init_sync(void) +{ + css_complete_work(); + return 0; +} +subsys_initcall_sync(channel_subsystem_init_sync); + +void channel_subsystem_reinit(void) +{ + struct channel_path *chp; + struct chp_id chpid; + + chsc_enable_facility(CHSC_SDA_OC_MSS); + chp_id_for_each(&chpid) { + chp = chpid_to_chp(chpid); + if (chp) + chp_update_desc(chp); + } + cmf_reactivate(); +} + +#ifdef CONFIG_PROC_FS +static ssize_t cio_settle_write(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + int ret; + + /* Handle pending CRW's. */ + crw_wait_for_channel_report(); + ret = css_complete_work(); + + return ret ? ret : count; +} + +static const struct file_operations cio_settle_proc_fops = { + .open = nonseekable_open, + .write = cio_settle_write, + .llseek = no_llseek, +}; + +static int __init cio_settle_init(void) +{ + struct proc_dir_entry *entry; + + entry = proc_create("cio_settle", S_IWUSR, NULL, + &cio_settle_proc_fops); + if (!entry) + return -ENOMEM; + return 0; +} +device_initcall(cio_settle_init); +#endif /*CONFIG_PROC_FS*/ + +int sch_is_pseudo_sch(struct subchannel *sch) +{ + if (!sch->dev.parent) + return 0; + return sch == to_css(sch->dev.parent)->pseudo_subchannel; +} + +static int css_bus_match(struct device *dev, struct device_driver *drv) +{ + struct subchannel *sch = to_subchannel(dev); + struct css_driver *driver = to_cssdriver(drv); + struct css_device_id *id; + + for (id = driver->subchannel_type; id->match_flags; id++) { + if (sch->st == id->type) + return 1; + } + + return 0; +} + +static int css_probe(struct device *dev) +{ + struct subchannel *sch; + int ret; + + sch = to_subchannel(dev); + sch->driver = to_cssdriver(dev->driver); + ret = sch->driver->probe ? sch->driver->probe(sch) : 0; + if (ret) + sch->driver = NULL; + return ret; +} + +static int css_remove(struct device *dev) +{ + struct subchannel *sch; + int ret; + + sch = to_subchannel(dev); + ret = sch->driver->remove ? sch->driver->remove(sch) : 0; + sch->driver = NULL; + return ret; +} + +static void css_shutdown(struct device *dev) +{ + struct subchannel *sch; + + sch = to_subchannel(dev); + if (sch->driver && sch->driver->shutdown) + sch->driver->shutdown(sch); +} + +static int css_uevent(struct device *dev, struct kobj_uevent_env *env) +{ + struct subchannel *sch = to_subchannel(dev); + int ret; + + ret = add_uevent_var(env, "ST=%01X", sch->st); + if (ret) + return ret; + ret = add_uevent_var(env, "MODALIAS=css:t%01X", sch->st); + return ret; +} + +static int css_pm_prepare(struct device *dev) +{ + struct subchannel *sch = to_subchannel(dev); + struct css_driver *drv; + + if (mutex_is_locked(&sch->reg_mutex)) + return -EAGAIN; + if (!sch->dev.driver) + return 0; + drv = to_cssdriver(sch->dev.driver); + /* Notify drivers that they may not register children. */ + return drv->prepare ? drv->prepare(sch) : 0; +} + +static void css_pm_complete(struct device *dev) +{ + struct subchannel *sch = to_subchannel(dev); + struct css_driver *drv; + + if (!sch->dev.driver) + return; + drv = to_cssdriver(sch->dev.driver); + if (drv->complete) + drv->complete(sch); +} + +static int css_pm_freeze(struct device *dev) +{ + struct subchannel *sch = to_subchannel(dev); + struct css_driver *drv; + + if (!sch->dev.driver) + return 0; + drv = to_cssdriver(sch->dev.driver); + return drv->freeze ? drv->freeze(sch) : 0; +} + +static int css_pm_thaw(struct device *dev) +{ + struct subchannel *sch = to_subchannel(dev); + struct css_driver *drv; + + if (!sch->dev.driver) + return 0; + drv = to_cssdriver(sch->dev.driver); + return drv->thaw ? drv->thaw(sch) : 0; +} + +static int css_pm_restore(struct device *dev) +{ + struct subchannel *sch = to_subchannel(dev); + struct css_driver *drv; + + css_update_ssd_info(sch); + if (!sch->dev.driver) + return 0; + drv = to_cssdriver(sch->dev.driver); + return drv->restore ? drv->restore(sch) : 0; +} + +static const struct dev_pm_ops css_pm_ops = { + .prepare = css_pm_prepare, + .complete = css_pm_complete, + .freeze = css_pm_freeze, + .thaw = css_pm_thaw, + .restore = css_pm_restore, +}; + +static struct bus_type css_bus_type = { + .name = "css", + .match = css_bus_match, + .probe = css_probe, + .remove = css_remove, + .shutdown = css_shutdown, + .uevent = css_uevent, + .pm = &css_pm_ops, +}; + +/** + * css_driver_register - register a css driver + * @cdrv: css driver to register + * + * This is mainly a wrapper around driver_register that sets name + * and bus_type in the embedded struct device_driver correctly. + */ +int css_driver_register(struct css_driver *cdrv) +{ + cdrv->drv.bus = &css_bus_type; + return driver_register(&cdrv->drv); +} +EXPORT_SYMBOL_GPL(css_driver_register); + +/** + * css_driver_unregister - unregister a css driver + * @cdrv: css driver to unregister + * + * This is a wrapper around driver_unregister. + */ +void css_driver_unregister(struct css_driver *cdrv) +{ + driver_unregister(&cdrv->drv); +} +EXPORT_SYMBOL_GPL(css_driver_unregister); |