// 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/proc_fs.h> #include <linux/genalloc.h> #include <linux/dma-mapping.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->driver_override); 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; sch->dev.dma_mask = &sch->dma_mask; device_initialize(&sch->dev); /* * The physical addresses for some of the dma structures that can * belong to a subchannel need to fit 31 bit width (e.g. ccw). */ ret = dma_set_coherent_mask(&sch->dev, DMA_BIT_MASK(31)); if (ret) goto err; /* * But we don't have such restrictions imposed on the stuff that * is handled by the streaming API. */ ret = dma_set_mask(&sch->dev, DMA_BIT_MASK(64)); if (ret) goto err; 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 ssize_t driver_override_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { struct subchannel *sch = to_subchannel(dev); char *driver_override, *old, *cp; /* We need to keep extra room for a newline */ if (count >= (PAGE_SIZE - 1)) return -EINVAL; driver_override = kstrndup(buf, count, GFP_KERNEL); if (!driver_override) return -ENOMEM; cp = strchr(driver_override, '\n'); if (cp) *cp = '\0'; device_lock(dev); old = sch->driver_override; if (strlen(driver_override)) { sch->driver_override = driver_override; } else { kfree(driver_override); sch->driver_override = NULL; } device_unlock(dev); kfree(old); return count; } static ssize_t driver_override_show(struct device *dev, struct device_attribute *attr, char *buf) { struct subchannel *sch = to_subchannel(dev); ssize_t len; device_lock(dev); len = snprintf(buf, PAGE_SIZE, "%s\n", sch->driver_override); device_unlock(dev); return len; } static DEVICE_ATTR_RW(driver_override); static struct attribute *subch_attrs[] = { &dev_attr_type.attr, &dev_attr_modalias.attr, &dev_attr_driver_override.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 struct attribute *io_subchannel_type_attrs[] = { &dev_attr_chpids.attr, &dev_attr_pimpampom.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, const void *data) { struct subchannel *sch; struct subchannel_id *schid = (void *)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 DEFINE_SPINLOCK(slow_subchannel_lock); static DECLARE_WAIT_QUEUE_HEAD(css_eval_wq); static atomic_t css_eval_scheduled; static int __init slow_subchannel_init(void) { atomic_set(&css_eval_scheduled, 0); 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->id_valid ? css->cssid : 0; } 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->id_valid) return -EINVAL; return sprintf(buf, "%x\n", css->cssid); } static DEVICE_ATTR_RO(real_cssid); static ssize_t rescan_store(struct device *dev, struct device_attribute *a, const char *buf, size_t count) { CIO_TRACE_EVENT(4, "usr-rescan"); css_schedule_eval_all(); css_complete_work(); return count; } static DEVICE_ATTR_WO(rescan); 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, &dev_attr_rescan.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; /* * We currently allocate notifier bits with this (using * css->device as the device argument with the DMA API) * and are fine with 64 bit addresses. */ ret = dma_coerce_mask_and_coherent(&css->device, DMA_BIT_MASK(64)); if (ret) { kfree(css); goto out_err; } mutex_init(&css->mutex); ret = chsc_get_cssid_iid(nr, &css->cssid, &css->iid); if (!ret) { css->id_valid = true; pr_info("Partition identifier %01x.%01x\n", css->cssid, css->iid); } 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, }; #define CIO_DMA_GFP (GFP_KERNEL | __GFP_ZERO) static struct gen_pool *cio_dma_pool; /* Currently cio supports only a single css */ struct device *cio_get_dma_css_dev(void) { return &channel_subsystems[0]->device; } struct gen_pool *cio_gp_dma_create(struct device *dma_dev, int nr_pages) { struct gen_pool *gp_dma; void *cpu_addr; dma_addr_t dma_addr; int i; gp_dma = gen_pool_create(3, -1); if (!gp_dma) return NULL; for (i = 0; i < nr_pages; ++i) { cpu_addr = dma_alloc_coherent(dma_dev, PAGE_SIZE, &dma_addr, CIO_DMA_GFP); if (!cpu_addr) return gp_dma; gen_pool_add_virt(gp_dma, (unsigned long) cpu_addr, dma_addr, PAGE_SIZE, -1); } return gp_dma; } static void __gp_dma_free_dma(struct gen_pool *pool, struct gen_pool_chunk *chunk, void *data) { size_t chunk_size = chunk->end_addr - chunk->start_addr + 1; dma_free_coherent((struct device *) data, chunk_size, (void *) chunk->start_addr, (dma_addr_t) chunk->phys_addr); } void cio_gp_dma_destroy(struct gen_pool *gp_dma, struct device *dma_dev) { if (!gp_dma) return; /* this is quite ugly but no better idea */ gen_pool_for_each_chunk(gp_dma, __gp_dma_free_dma, dma_dev); gen_pool_destroy(gp_dma); } static int cio_dma_pool_init(void) { /* No need to free up the resources: compiled in */ cio_dma_pool = cio_gp_dma_create(cio_get_dma_css_dev(), 1); if (!cio_dma_pool) return -ENOMEM; return 0; } void *cio_gp_dma_zalloc(struct gen_pool *gp_dma, struct device *dma_dev, size_t size) { dma_addr_t dma_addr; unsigned long addr; size_t chunk_size; if (!gp_dma) return NULL; addr = gen_pool_alloc(gp_dma, size); while (!addr) { chunk_size = round_up(size, PAGE_SIZE); addr = (unsigned long) dma_alloc_coherent(dma_dev, chunk_size, &dma_addr, CIO_DMA_GFP); if (!addr) return NULL; gen_pool_add_virt(gp_dma, addr, dma_addr, chunk_size, -1); addr = gen_pool_alloc(gp_dma, size); } return (void *) addr; } void cio_gp_dma_free(struct gen_pool *gp_dma, void *cpu_addr, size_t size) { if (!cpu_addr) return; memset(cpu_addr, 0, size); gen_pool_free(gp_dma, (unsigned long) cpu_addr, size); } /* * Allocate dma memory from the css global pool. Intended for memory not * specific to any single device within the css. The allocated memory * is not guaranteed to be 31-bit addressable. * * Caution: Not suitable for early stuff like console. */ void *cio_dma_zalloc(size_t size) { return cio_gp_dma_zalloc(cio_dma_pool, cio_get_dma_css_dev(), size); } void cio_dma_free(void *cpu_addr, size_t size) { cio_gp_dma_free(cio_dma_pool, cpu_addr, size); } /* * 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 = cio_dma_pool_init(); if (ret) goto out_unregister_rn; airq_init(); css_init_done = 1; /* Enable default isc for I/O subchannels. */ isc_register(IO_SCH_ISC); return 0; out_unregister_rn: unregister_reboot_notifier(&css_reboot_notifier); 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); #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 proc_ops cio_settle_proc_ops = { .proc_open = nonseekable_open, .proc_write = cio_settle_write, .proc_lseek = 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_ops); 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; /* When driver_override is set, only bind to the matching driver */ if (sch->driver_override && strcmp(sch->driver_override, drv->name)) return 0; 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 struct bus_type css_bus_type = { .name = "css", .match = css_bus_match, .probe = css_probe, .remove = css_remove, .shutdown = css_shutdown, .uevent = css_uevent, }; /** * 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);