v4.19.13 snapshot.
diff --git a/drivers/s390/cio/css.c b/drivers/s390/cio/css.c
new file mode 100644
index 0000000..aea5029
--- /dev/null
+++ b/drivers/s390/cio/css.c
@@ -0,0 +1,1380 @@
+// 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 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, 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);
+ }
+ 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)
+{
+ 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);