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OpenCloudOS-Kernel/drivers/s390/cio/css.c

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// 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);
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