/* * Copyright IBM Corp. 1999, 2010 * Author(s): Cornelia Huck (cornelia.huck@de.ibm.com) * Arnd Bergmann (arndb@de.ibm.com) * Peter Oberparleiter <peter.oberparleiter@de.ibm.com> */ #include <linux/bug.h> #include <linux/workqueue.h> #include <linux/spinlock.h> #include <linux/export.h> #include <linux/sched.h> #include <linux/init.h> #include <linux/jiffies.h> #include <linux/wait.h> #include <linux/mutex.h> #include <linux/errno.h> #include <linux/slab.h> #include <asm/chpid.h> #include <asm/sclp.h> #include <asm/crw.h> #include "cio.h" #include "css.h" #include "ioasm.h" #include "cio_debug.h" #include "chp.h" #define to_channelpath(device) container_of(device, struct channel_path, dev) #define CHP_INFO_UPDATE_INTERVAL 1*HZ enum cfg_task_t { cfg_none, cfg_configure, cfg_deconfigure }; /* Map for pending configure tasks. */ static enum cfg_task_t chp_cfg_task[__MAX_CSSID + 1][__MAX_CHPID + 1]; static DEFINE_MUTEX(cfg_lock); static int cfg_busy; /* Map for channel-path status. */ static struct sclp_chp_info chp_info; static DEFINE_MUTEX(info_lock); /* Time after which channel-path status may be outdated. */ static unsigned long chp_info_expires; /* Workqueue to perform pending configure tasks. */ static struct workqueue_struct *chp_wq; static struct work_struct cfg_work; /* Wait queue for configure completion events. */ static wait_queue_head_t cfg_wait_queue; /* Set vary state for given chpid. */ static void set_chp_logically_online(struct chp_id chpid, int onoff) { chpid_to_chp(chpid)->state = onoff; } /* On success return 0 if channel-path is varied offline, 1 if it is varied * online. Return -ENODEV if channel-path is not registered. */ int chp_get_status(struct chp_id chpid) { return (chpid_to_chp(chpid) ? chpid_to_chp(chpid)->state : -ENODEV); } /** * chp_get_sch_opm - return opm for subchannel * @sch: subchannel * * Calculate and return the operational path mask (opm) based on the chpids * used by the subchannel and the status of the associated channel-paths. */ u8 chp_get_sch_opm(struct subchannel *sch) { struct chp_id chpid; int opm; int i; opm = 0; chp_id_init(&chpid); for (i = 0; i < 8; i++) { opm <<= 1; chpid.id = sch->schib.pmcw.chpid[i]; if (chp_get_status(chpid) != 0) opm |= 1; } return opm; } EXPORT_SYMBOL_GPL(chp_get_sch_opm); /** * chp_is_registered - check if a channel-path is registered * @chpid: channel-path ID * * Return non-zero if a channel-path with the given chpid is registered, * zero otherwise. */ int chp_is_registered(struct chp_id chpid) { return chpid_to_chp(chpid) != NULL; } /* * Function: s390_vary_chpid * Varies the specified chpid online or offline */ static int s390_vary_chpid(struct chp_id chpid, int on) { char dbf_text[15]; int status; sprintf(dbf_text, on?"varyon%x.%02x":"varyoff%x.%02x", chpid.cssid, chpid.id); CIO_TRACE_EVENT(2, dbf_text); status = chp_get_status(chpid); if (!on && !status) return 0; set_chp_logically_online(chpid, on); chsc_chp_vary(chpid, on); return 0; } /* * Channel measurement related functions */ static ssize_t chp_measurement_chars_read(struct file *filp, struct kobject *kobj, struct bin_attribute *bin_attr, char *buf, loff_t off, size_t count) { struct channel_path *chp; struct device *device; device = container_of(kobj, struct device, kobj); chp = to_channelpath(device); if (!chp->cmg_chars) return 0; return memory_read_from_buffer(buf, count, &off, chp->cmg_chars, sizeof(struct cmg_chars)); } static struct bin_attribute chp_measurement_chars_attr = { .attr = { .name = "measurement_chars", .mode = S_IRUSR, }, .size = sizeof(struct cmg_chars), .read = chp_measurement_chars_read, }; static void chp_measurement_copy_block(struct cmg_entry *buf, struct channel_subsystem *css, struct chp_id chpid) { void *area; struct cmg_entry *entry, reference_buf; int idx; if (chpid.id < 128) { area = css->cub_addr1; idx = chpid.id; } else { area = css->cub_addr2; idx = chpid.id - 128; } entry = area + (idx * sizeof(struct cmg_entry)); do { memcpy(buf, entry, sizeof(*entry)); memcpy(&reference_buf, entry, sizeof(*entry)); } while (reference_buf.values[0] != buf->values[0]); } static ssize_t chp_measurement_read(struct file *filp, struct kobject *kobj, struct bin_attribute *bin_attr, char *buf, loff_t off, size_t count) { struct channel_path *chp; struct channel_subsystem *css; struct device *device; unsigned int size; device = container_of(kobj, struct device, kobj); chp = to_channelpath(device); css = to_css(chp->dev.parent); size = sizeof(struct cmg_entry); /* Only allow single reads. */ if (off || count < size) return 0; chp_measurement_copy_block((struct cmg_entry *)buf, css, chp->chpid); count = size; return count; } static struct bin_attribute chp_measurement_attr = { .attr = { .name = "measurement", .mode = S_IRUSR, }, .size = sizeof(struct cmg_entry), .read = chp_measurement_read, }; void chp_remove_cmg_attr(struct channel_path *chp) { device_remove_bin_file(&chp->dev, &chp_measurement_chars_attr); device_remove_bin_file(&chp->dev, &chp_measurement_attr); } int chp_add_cmg_attr(struct channel_path *chp) { int ret; ret = device_create_bin_file(&chp->dev, &chp_measurement_chars_attr); if (ret) return ret; ret = device_create_bin_file(&chp->dev, &chp_measurement_attr); if (ret) device_remove_bin_file(&chp->dev, &chp_measurement_chars_attr); return ret; } /* * Files for the channel path entries. */ static ssize_t chp_status_show(struct device *dev, struct device_attribute *attr, char *buf) { struct channel_path *chp = to_channelpath(dev); int status; mutex_lock(&chp->lock); status = chp->state; mutex_unlock(&chp->lock); return status ? sprintf(buf, "online\n") : sprintf(buf, "offline\n"); } static ssize_t chp_status_write(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { struct channel_path *cp = to_channelpath(dev); char cmd[10]; int num_args; int error; num_args = sscanf(buf, "%5s", cmd); if (!num_args) return count; if (!strnicmp(cmd, "on", 2) || !strcmp(cmd, "1")) { mutex_lock(&cp->lock); error = s390_vary_chpid(cp->chpid, 1); mutex_unlock(&cp->lock); } else if (!strnicmp(cmd, "off", 3) || !strcmp(cmd, "0")) { mutex_lock(&cp->lock); error = s390_vary_chpid(cp->chpid, 0); mutex_unlock(&cp->lock); } else error = -EINVAL; return error < 0 ? error : count; } static DEVICE_ATTR(status, 0644, chp_status_show, chp_status_write); static ssize_t chp_configure_show(struct device *dev, struct device_attribute *attr, char *buf) { struct channel_path *cp; int status; cp = to_channelpath(dev); status = chp_info_get_status(cp->chpid); if (status < 0) return status; return snprintf(buf, PAGE_SIZE, "%d\n", status); } static int cfg_wait_idle(void); static ssize_t chp_configure_write(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { struct channel_path *cp; int val; char delim; if (sscanf(buf, "%d %c", &val, &delim) != 1) return -EINVAL; if (val != 0 && val != 1) return -EINVAL; cp = to_channelpath(dev); chp_cfg_schedule(cp->chpid, val); cfg_wait_idle(); return count; } static DEVICE_ATTR(configure, 0644, chp_configure_show, chp_configure_write); static ssize_t chp_type_show(struct device *dev, struct device_attribute *attr, char *buf) { struct channel_path *chp = to_channelpath(dev); u8 type; mutex_lock(&chp->lock); type = chp->desc.desc; mutex_unlock(&chp->lock); return sprintf(buf, "%x\n", type); } static DEVICE_ATTR(type, 0444, chp_type_show, NULL); static ssize_t chp_cmg_show(struct device *dev, struct device_attribute *attr, char *buf) { struct channel_path *chp = to_channelpath(dev); if (!chp) return 0; if (chp->cmg == -1) /* channel measurements not available */ return sprintf(buf, "unknown\n"); return sprintf(buf, "%x\n", chp->cmg); } static DEVICE_ATTR(cmg, 0444, chp_cmg_show, NULL); static ssize_t chp_shared_show(struct device *dev, struct device_attribute *attr, char *buf) { struct channel_path *chp = to_channelpath(dev); if (!chp) return 0; if (chp->shared == -1) /* channel measurements not available */ return sprintf(buf, "unknown\n"); return sprintf(buf, "%x\n", chp->shared); } static DEVICE_ATTR(shared, 0444, chp_shared_show, NULL); static struct attribute *chp_attrs[] = { &dev_attr_status.attr, &dev_attr_configure.attr, &dev_attr_type.attr, &dev_attr_cmg.attr, &dev_attr_shared.attr, NULL, }; static struct attribute_group chp_attr_group = { .attrs = chp_attrs, }; static const struct attribute_group *chp_attr_groups[] = { &chp_attr_group, NULL, }; static void chp_release(struct device *dev) { struct channel_path *cp; cp = to_channelpath(dev); kfree(cp); } /** * chp_new - register a new channel-path * @chpid - channel-path ID * * Create and register data structure representing new channel-path. Return * zero on success, non-zero otherwise. */ int chp_new(struct chp_id chpid) { struct channel_path *chp; int ret; if (chp_is_registered(chpid)) return 0; chp = kzalloc(sizeof(struct channel_path), GFP_KERNEL); if (!chp) return -ENOMEM; /* fill in status, etc. */ chp->chpid = chpid; chp->state = 1; chp->dev.parent = &channel_subsystems[chpid.cssid]->device; chp->dev.groups = chp_attr_groups; chp->dev.release = chp_release; mutex_init(&chp->lock); /* Obtain channel path description and fill it in. */ ret = chsc_determine_base_channel_path_desc(chpid, &chp->desc); if (ret) goto out_free; if ((chp->desc.flags & 0x80) == 0) { ret = -ENODEV; goto out_free; } /* Get channel-measurement characteristics. */ if (css_chsc_characteristics.scmc && css_chsc_characteristics.secm) { ret = chsc_get_channel_measurement_chars(chp); if (ret) goto out_free; } else { chp->cmg = -1; } dev_set_name(&chp->dev, "chp%x.%02x", chpid.cssid, chpid.id); /* make it known to the system */ ret = device_register(&chp->dev); if (ret) { CIO_MSG_EVENT(0, "Could not register chp%x.%02x: %d\n", chpid.cssid, chpid.id, ret); put_device(&chp->dev); goto out; } mutex_lock(&channel_subsystems[chpid.cssid]->mutex); if (channel_subsystems[chpid.cssid]->cm_enabled) { ret = chp_add_cmg_attr(chp); if (ret) { device_unregister(&chp->dev); mutex_unlock(&channel_subsystems[chpid.cssid]->mutex); goto out; } } channel_subsystems[chpid.cssid]->chps[chpid.id] = chp; mutex_unlock(&channel_subsystems[chpid.cssid]->mutex); goto out; out_free: kfree(chp); out: return ret; } /** * chp_get_chp_desc - return newly allocated channel-path description * @chpid: channel-path ID * * On success return a newly allocated copy of the channel-path description * data associated with the given channel-path ID. Return %NULL on error. */ void *chp_get_chp_desc(struct chp_id chpid) { struct channel_path *chp; struct channel_path_desc *desc; chp = chpid_to_chp(chpid); if (!chp) return NULL; desc = kmalloc(sizeof(struct channel_path_desc), GFP_KERNEL); if (!desc) return NULL; mutex_lock(&chp->lock); memcpy(desc, &chp->desc, sizeof(struct channel_path_desc)); mutex_unlock(&chp->lock); return desc; } /** * chp_process_crw - process channel-path status change * @crw0: channel report-word to handler * @crw1: second channel-report word (always NULL) * @overflow: crw overflow indication * * Handle channel-report-words indicating that the status of a channel-path * has changed. */ static void chp_process_crw(struct crw *crw0, struct crw *crw1, int overflow) { struct chp_id chpid; if (overflow) { css_schedule_eval_all(); return; } CIO_CRW_EVENT(2, "CRW 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); /* * Check for solicited machine checks. These are * created by reset channel path and need not be * handled here. */ if (crw0->slct) { CIO_CRW_EVENT(2, "solicited machine check for " "channel path %02X\n", crw0->rsid); return; } chp_id_init(&chpid); chpid.id = crw0->rsid; switch (crw0->erc) { case CRW_ERC_IPARM: /* Path has come. */ if (!chp_is_registered(chpid)) chp_new(chpid); chsc_chp_online(chpid); break; case CRW_ERC_PERRI: /* Path has gone. */ case CRW_ERC_PERRN: chsc_chp_offline(chpid); break; default: CIO_CRW_EVENT(2, "Don't know how to handle erc=%x\n", crw0->erc); } } int chp_ssd_get_mask(struct chsc_ssd_info *ssd, struct chp_link *link) { int i; int mask; for (i = 0; i < 8; i++) { mask = 0x80 >> i; if (!(ssd->path_mask & mask)) continue; if (!chp_id_is_equal(&ssd->chpid[i], &link->chpid)) continue; if ((ssd->fla_valid_mask & mask) && ((ssd->fla[i] & link->fla_mask) != link->fla)) continue; return mask; } return 0; } EXPORT_SYMBOL_GPL(chp_ssd_get_mask); static inline int info_bit_num(struct chp_id id) { return id.id + id.cssid * (__MAX_CHPID + 1); } /* Force chp_info refresh on next call to info_validate(). */ static void info_expire(void) { mutex_lock(&info_lock); chp_info_expires = jiffies - 1; mutex_unlock(&info_lock); } /* Ensure that chp_info is up-to-date. */ static int info_update(void) { int rc; mutex_lock(&info_lock); rc = 0; if (time_after(jiffies, chp_info_expires)) { /* Data is too old, update. */ rc = sclp_chp_read_info(&chp_info); chp_info_expires = jiffies + CHP_INFO_UPDATE_INTERVAL ; } mutex_unlock(&info_lock); return rc; } /** * chp_info_get_status - retrieve configure status of a channel-path * @chpid: channel-path ID * * On success, return 0 for standby, 1 for configured, 2 for reserved, * 3 for not recognized. Return negative error code on error. */ int chp_info_get_status(struct chp_id chpid) { int rc; int bit; rc = info_update(); if (rc) return rc; bit = info_bit_num(chpid); mutex_lock(&info_lock); if (!chp_test_bit(chp_info.recognized, bit)) rc = CHP_STATUS_NOT_RECOGNIZED; else if (chp_test_bit(chp_info.configured, bit)) rc = CHP_STATUS_CONFIGURED; else if (chp_test_bit(chp_info.standby, bit)) rc = CHP_STATUS_STANDBY; else rc = CHP_STATUS_RESERVED; mutex_unlock(&info_lock); return rc; } /* Return configure task for chpid. */ static enum cfg_task_t cfg_get_task(struct chp_id chpid) { return chp_cfg_task[chpid.cssid][chpid.id]; } /* Set configure task for chpid. */ static void cfg_set_task(struct chp_id chpid, enum cfg_task_t cfg) { chp_cfg_task[chpid.cssid][chpid.id] = cfg; } /* Perform one configure/deconfigure request. Reschedule work function until * last request. */ static void cfg_func(struct work_struct *work) { struct chp_id chpid; enum cfg_task_t t; int rc; mutex_lock(&cfg_lock); t = cfg_none; chp_id_for_each(&chpid) { t = cfg_get_task(chpid); if (t != cfg_none) { cfg_set_task(chpid, cfg_none); break; } } mutex_unlock(&cfg_lock); switch (t) { case cfg_configure: rc = sclp_chp_configure(chpid); if (rc) CIO_MSG_EVENT(2, "chp: sclp_chp_configure(%x.%02x)=" "%d\n", chpid.cssid, chpid.id, rc); else { info_expire(); chsc_chp_online(chpid); } break; case cfg_deconfigure: rc = sclp_chp_deconfigure(chpid); if (rc) CIO_MSG_EVENT(2, "chp: sclp_chp_deconfigure(%x.%02x)=" "%d\n", chpid.cssid, chpid.id, rc); else { info_expire(); chsc_chp_offline(chpid); } break; case cfg_none: /* Get updated information after last change. */ info_update(); mutex_lock(&cfg_lock); cfg_busy = 0; mutex_unlock(&cfg_lock); wake_up_interruptible(&cfg_wait_queue); return; } queue_work(chp_wq, &cfg_work); } /** * chp_cfg_schedule - schedule chpid configuration request * @chpid - channel-path ID * @configure - Non-zero for configure, zero for deconfigure * * Schedule a channel-path configuration/deconfiguration request. */ void chp_cfg_schedule(struct chp_id chpid, int configure) { CIO_MSG_EVENT(2, "chp_cfg_sched%x.%02x=%d\n", chpid.cssid, chpid.id, configure); mutex_lock(&cfg_lock); cfg_set_task(chpid, configure ? cfg_configure : cfg_deconfigure); cfg_busy = 1; mutex_unlock(&cfg_lock); queue_work(chp_wq, &cfg_work); } /** * chp_cfg_cancel_deconfigure - cancel chpid deconfiguration request * @chpid - channel-path ID * * Cancel an active channel-path deconfiguration request if it has not yet * been performed. */ void chp_cfg_cancel_deconfigure(struct chp_id chpid) { CIO_MSG_EVENT(2, "chp_cfg_cancel:%x.%02x\n", chpid.cssid, chpid.id); mutex_lock(&cfg_lock); if (cfg_get_task(chpid) == cfg_deconfigure) cfg_set_task(chpid, cfg_none); mutex_unlock(&cfg_lock); } static int cfg_wait_idle(void) { if (wait_event_interruptible(cfg_wait_queue, !cfg_busy)) return -ERESTARTSYS; return 0; } static int __init chp_init(void) { struct chp_id chpid; int ret; ret = crw_register_handler(CRW_RSC_CPATH, chp_process_crw); if (ret) return ret; chp_wq = create_singlethread_workqueue("cio_chp"); if (!chp_wq) { crw_unregister_handler(CRW_RSC_CPATH); return -ENOMEM; } INIT_WORK(&cfg_work, cfg_func); init_waitqueue_head(&cfg_wait_queue); if (info_update()) return 0; /* Register available channel-paths. */ chp_id_for_each(&chpid) { if (chp_info_get_status(chpid) != CHP_STATUS_NOT_RECOGNIZED) chp_new(chpid); } return 0; } subsys_initcall(chp_init);