diff options
Diffstat (limited to 'drivers/s390/cio/chp.c')
| -rw-r--r-- | drivers/s390/cio/chp.c | 834 |
1 files changed, 834 insertions, 0 deletions
diff --git a/drivers/s390/cio/chp.c b/drivers/s390/cio/chp.c new file mode 100644 index 000000000..1fd982b4d --- /dev/null +++ b/drivers/s390/cio/chp.c @@ -0,0 +1,834 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * 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_SPINLOCK(cfg_lock); + +/* 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struct sclp_chp_info chp_info; +static DEFINE_MUTEX(info_lock); + +/* Time after which channel-path status may be outdated.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; + +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 == -1) + return 0; + + return memory_read_from_buffer(buf, count, &off, &chp->cmg_chars, + sizeof(chp->cmg_chars)); +} + +static const 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 const 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; + + /* Wait until previous actions have settled. */ + css_wait_for_slow_path(); + + if (!strncasecmp(cmd, "on", 2) || !strcmp(cmd, "1")) { + mutex_lock(&cp->lock); + error = s390_vary_chpid(cp->chpid, 1); + mutex_unlock(&cp->lock); + } else if (!strncasecmp(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 ssize_t chp_chid_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct channel_path *chp = to_channelpath(dev); + ssize_t rc; + + mutex_lock(&chp->lock); + if (chp->desc_fmt1.flags & 0x10) + rc = sprintf(buf, "%04x\n", chp->desc_fmt1.chid); + else + rc = 0; + mutex_unlock(&chp->lock); + + return rc; +} +static DEVICE_ATTR(chid, 0444, chp_chid_show, NULL); + +static ssize_t chp_chid_external_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct channel_path *chp = to_channelpath(dev); + ssize_t rc; + + mutex_lock(&chp->lock); + if (chp->desc_fmt1.flags & 0x10) + rc = sprintf(buf, "%x\n", chp->desc_fmt1.flags & 0x8 ? 1 : 0); + else + rc = 0; + mutex_unlock(&chp->lock); + + return rc; +} +static DEVICE_ATTR(chid_external, 0444, chp_chid_external_show, NULL); + +static ssize_t util_string_read(struct file *filp, struct kobject *kobj, + struct bin_attribute *attr, char *buf, + loff_t off, size_t count) +{ + struct channel_path *chp = to_channelpath(kobj_to_dev(kobj)); + ssize_t rc; + + mutex_lock(&chp->lock); + rc = memory_read_from_buffer(buf, count, &off, chp->desc_fmt3.util_str, + sizeof(chp->desc_fmt3.util_str)); + mutex_unlock(&chp->lock); + + return rc; +} +static BIN_ATTR_RO(util_string, + sizeof(((struct channel_path_desc_fmt3 *)0)->util_str)); + +static struct bin_attribute *chp_bin_attrs[] = { + &bin_attr_util_string, + 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, + &dev_attr_chid.attr, + &dev_attr_chid_external.attr, + NULL, +}; +static struct attribute_group chp_attr_group = { + .attrs = chp_attrs, + .bin_attrs = chp_bin_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_update_desc - update channel-path description + * @chp: channel-path + * + * Update the channel-path description of the specified channel-path + * including channel measurement related information. + * Return zero on success, non-zero otherwise. + */ +int chp_update_desc(struct channel_path *chp) +{ + int rc; + + rc = chsc_determine_fmt0_channel_path_desc(chp->chpid, &chp->desc); + if (rc) + return rc; + + /* + * Fetching the following data is optional. Not all machines or + * hypervisors implement the required chsc commands. + */ + chsc_determine_fmt1_channel_path_desc(chp->chpid, &chp->desc_fmt1); + chsc_determine_fmt3_channel_path_desc(chp->chpid, &chp->desc_fmt3); + chsc_get_channel_measurement_chars(chp); + + return 0; +} + +/** + * 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_subsystem *css = css_by_id(chpid.cssid); + struct channel_path *chp; + int ret = 0; + + mutex_lock(&css->mutex); + if (chp_is_registered(chpid)) + goto out; + + chp = kzalloc(sizeof(struct channel_path), GFP_KERNEL); + if (!chp) { + ret = -ENOMEM; + goto out; + } + /* fill in status, etc. */ + chp->chpid = chpid; + chp->state = 1; + chp->dev.parent = &css->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 = chp_update_desc(chp); + if (ret) + goto out_free; + if ((chp->desc.flags & 0x80) == 0) { + ret = -ENODEV; + goto out_free; + } + 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; + } + + if (css->cm_enabled) { + ret = chp_add_cmg_attr(chp); + if (ret) { + device_unregister(&chp->dev); + goto out; + } + } + css->chps[chpid.id] = chp; + goto out; +out_free: + kfree(chp); +out: + mutex_unlock(&css->mutex); + 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. + */ +struct channel_path_desc_fmt0 *chp_get_chp_desc(struct chp_id chpid) +{ + struct channel_path *chp; + struct channel_path_desc_fmt0 *desc; + + chp = chpid_to_chp(chpid); + if (!chp) + return NULL; + desc = kmalloc(sizeof(*desc), GFP_KERNEL); + if (!desc) + return NULL; + + mutex_lock(&chp->lock); + memcpy(desc, &chp->desc, sizeof(*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. */ + case CRW_ERC_INIT: + 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; +} + +/* Fetch the first configure task. Set chpid accordingly. */ +static enum cfg_task_t chp_cfg_fetch_task(struct chp_id *chpid) +{ + enum cfg_task_t t = cfg_none; + + chp_id_for_each(chpid) { + t = cfg_get_task(*chpid); + if (t != cfg_none) + break; + } + + return t; +} + +/* 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; + + spin_lock(&cfg_lock); + t = chp_cfg_fetch_task(&chpid); + spin_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(); + wake_up_interruptible(&cfg_wait_queue); + return; + } + spin_lock(&cfg_lock); + if (t == cfg_get_task(chpid)) + cfg_set_task(chpid, cfg_none); + spin_unlock(&cfg_lock); + schedule_work(&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); + spin_lock(&cfg_lock); + cfg_set_task(chpid, configure ? cfg_configure : cfg_deconfigure); + spin_unlock(&cfg_lock); + schedule_work(&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); + spin_lock(&cfg_lock); + if (cfg_get_task(chpid) == cfg_deconfigure) + cfg_set_task(chpid, cfg_none); + spin_unlock(&cfg_lock); +} + +static bool cfg_idle(void) +{ + struct chp_id chpid; + enum cfg_task_t t; + + spin_lock(&cfg_lock); + t = chp_cfg_fetch_task(&chpid); + spin_unlock(&cfg_lock); + + return t == cfg_none; +} + +static int cfg_wait_idle(void) +{ + if (wait_event_interruptible(cfg_wait_queue, cfg_idle())) + return -ERESTARTSYS; + return 0; +} + +static int __init chp_init(void) +{ + struct chp_id chpid; + int state, ret; + + ret = crw_register_handler(CRW_RSC_CPATH, chp_process_crw); + if (ret) + return ret; + 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) { + state = chp_info_get_status(chpid); + if (state == CHP_STATUS_CONFIGURED || + state == CHP_STATUS_STANDBY) + chp_new(chpid); + } + + return 0; +} + +subsys_initcall(chp_init); |