linux-sg2042/drivers/s390/cio/css.c

997 lines
22 KiB
C

/*
* drivers/s390/cio/css.c
* driver for channel subsystem
*
* Copyright IBM Corp. 2002,2008
* 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/module.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 <asm/isc.h>
#include <asm/crw.h>
#include "css.h"
#include "cio.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;
static int need_reprobe = 0;
static int max_ssid = 0;
struct channel_subsystem *channel_subsystems[__MAX_CSSID + 1];
int
for_each_subchannel(int(*fn)(struct subchannel_id, void *), void *data)
{
struct subchannel_id schid;
int ret;
init_subchannel_id(&schid);
ret = -ENODEV;
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;
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;
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 struct subchannel *
css_alloc_subchannel(struct subchannel_id schid)
{
struct subchannel *sch;
int ret;
sch = kmalloc (sizeof (*sch), GFP_KERNEL | GFP_DMA);
if (sch == NULL)
return ERR_PTR(-ENOMEM);
ret = cio_validate_subchannel (sch, schid);
if (ret < 0) {
kfree(sch);
return ERR_PTR(ret);
}
return sch;
}
static void
css_free_subchannel(struct subchannel *sch)
{
if (sch) {
/* Reset intparm to zeroes. */
sch->config.intparm = 0;
cio_commit_config(sch);
kfree(sch->lock);
kfree(sch);
}
}
static void
css_subchannel_release(struct device *dev)
{
struct subchannel *sch;
sch = to_subchannel(dev);
if (!cio_is_console(sch->schid)) {
kfree(sch->lock);
kfree(sch);
}
}
static int css_sch_device_register(struct subchannel *sch)
{
int ret;
mutex_lock(&sch->reg_mutex);
ret = device_register(&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)
if (!chp_is_registered(ssd->chpid[i]))
chp_new(ssd->chpid[i]);
}
}
void css_update_ssd_info(struct subchannel *sch)
{
int ret;
if (cio_is_console(sch->schid)) {
/* Console is initialized too early for functions requiring
* memory allocation. */
ssd_from_pmcw(&sch->ssd_info, &sch->schib.pmcw);
} else {
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(type, 0444, type_show, NULL);
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(modalias, 0444, modalias_show, NULL);
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 struct attribute_group *default_subch_attr_groups[] = {
&subch_attr_group,
NULL,
};
static 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.release = &css_subchannel_release;
sch->dev.groups = default_subch_attr_groups;
/*
* 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;
}
int css_probe_device(struct subchannel_id schid)
{
int ret;
struct subchannel *sch;
sch = css_alloc_subchannel(schid);
if (IS_ERR(sch))
return PTR_ERR(sch);
ret = css_register_subchannel(sch);
if (ret)
css_free_subchannel(sch);
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;
if (!slow) {
/* Will be done on the slow path. */
return -EAGAIN;
}
if (stsch_err(schid, &schib) || !css_sch_is_valid(&schib)) {
/* Unusable - ignore. */
return 0;
}
CIO_MSG_EVENT(4, "Evaluating schid 0.%x.%04x, event %d, unknown, "
"slow path.\n", schid.ssid, schid.sch_no, CIO_OPER);
return css_probe_device(schid);
}
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");
}
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);
}
static struct idset *slow_subchannel_set;
static spinlock_t slow_subchannel_lock;
static int __init slow_subchannel_init(void)
{
spin_lock_init(&slow_subchannel_lock);
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 */
break;
default:
rc = 0;
}
}
return rc;
}
static void css_slow_path_func(struct work_struct *unused)
{
CIO_TRACE_EVENT(4, "slowpath");
for_each_subchannel_staged(slow_eval_known_fn, slow_eval_unknown_fn,
NULL);
}
static DECLARE_WORK(slow_path_work, css_slow_path_func);
struct workqueue_struct *slow_path_wq;
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);
queue_work(slow_path_wq, &slow_path_work);
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);
queue_work(slow_path_wq, &slow_path_work);
spin_unlock_irqrestore(&slow_subchannel_lock, flags);
}
void css_wait_for_slow_path(void)
{
flush_workqueue(slow_path_wq);
}
/* Reprobe subchannel if unregistered. */
static int reprobe_subchannel(struct subchannel_id schid, void *data)
{
int ret;
CIO_MSG_EVENT(6, "cio: reprobe 0.%x.%04x\n",
schid.ssid, schid.sch_no);
if (need_reprobe)
return -EAGAIN;
ret = css_probe_device(schid);
switch (ret) {
case 0:
break;
case -ENXIO:
case -ENOMEM:
case -EIO:
/* These should abort looping */
break;
default:
ret = 0;
}
return ret;
}
static void reprobe_after_idle(struct work_struct *unused)
{
/* Make sure initial subchannel scan is done. */
wait_event(ccw_device_init_wq,
atomic_read(&ccw_device_init_count) == 0);
if (need_reprobe)
css_schedule_reprobe();
}
static DECLARE_WORK(reprobe_idle_work, reprobe_after_idle);
/* Work function used to reprobe all unregistered subchannels. */
static void reprobe_all(struct work_struct *unused)
{
int ret;
CIO_MSG_EVENT(4, "reprobe start\n");
/* Make sure initial subchannel scan is done. */
if (atomic_read(&ccw_device_init_count) != 0) {
queue_work(ccw_device_work, &reprobe_idle_work);
return;
}
need_reprobe = 0;
ret = for_each_subchannel_staged(NULL, reprobe_subchannel, NULL);
CIO_MSG_EVENT(4, "reprobe done (rc=%d, need_reprobe=%d)\n", ret,
need_reprobe);
}
static DECLARE_WORK(css_reprobe_work, reprobe_all);
/* Schedule reprobing of all unregistered subchannels. */
void css_schedule_reprobe(void)
{
need_reprobe = 1;
queue_work(slow_path_wq, &css_reprobe_work);
}
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;
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 >> 8) & 3;
/*
* 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 int __init
__init_channel_subsystem(struct subchannel_id schid, void *data)
{
struct subchannel *sch;
int ret;
if (cio_is_console(schid))
sch = cio_get_console_subchannel();
else {
sch = css_alloc_subchannel(schid);
if (IS_ERR(sch))
ret = PTR_ERR(sch);
else
ret = 0;
switch (ret) {
case 0:
break;
case -ENOMEM:
panic("Out of memory in init_channel_subsystem\n");
/* -ENXIO: no more subchannels. */
case -ENXIO:
return ret;
/* -EIO: this subchannel set not supported. */
case -EIO:
return ret;
default:
return 0;
}
}
/*
* We register ALL valid subchannels in ioinfo, even those
* that have been present before init_channel_subsystem.
* These subchannels can't have been registered yet (kmalloc
* not working) so we do it now. This is true e.g. for the
* console subchannel.
*/
css_register_subchannel(sch);
return 0;
}
static void __init
css_generate_pgid(struct channel_subsystem *css, u32 tod_high)
{
if (css_general_characteristics.mcss) {
css->global_pgid.pgid_high.ext_cssid.version = 0x80;
css->global_pgid.pgid_high.ext_cssid.cssid = css->cssid;
} else {
#ifdef CONFIG_SMP
css->global_pgid.pgid_high.cpu_addr = stap();
#else
css->global_pgid.pgid_high.cpu_addr = 0;
#endif
}
css->global_pgid.cpu_id = ((cpuid_t *) __LC_CPUID)->ident;
css->global_pgid.cpu_model = ((cpuid_t *) __LC_CPUID)->machine;
css->global_pgid.tod_high = tod_high;
}
static void
channel_subsystem_release(struct device *dev)
{
struct channel_subsystem *css;
css = to_css(dev);
mutex_destroy(&css->mutex);
if (css->pseudo_subchannel) {
/* Implies that it has been generated but never registered. */
css_subchannel_release(&css->pseudo_subchannel->dev);
css->pseudo_subchannel = NULL;
}
kfree(css);
}
static ssize_t
css_cm_enable_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct channel_subsystem *css = to_css(dev);
int ret;
if (!css)
return 0;
mutex_lock(&css->mutex);
ret = sprintf(buf, "%x\n", css->cm_enabled);
mutex_unlock(&css->mutex);
return ret;
}
static ssize_t
css_cm_enable_store(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
struct channel_subsystem *css = to_css(dev);
int ret;
unsigned long val;
ret = strict_strtoul(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(cm_enable, 0644, css_cm_enable_show, css_cm_enable_store);
static int __init setup_css(int nr)
{
u32 tod_high;
int ret;
struct channel_subsystem *css;
css = channel_subsystems[nr];
memset(css, 0, sizeof(struct channel_subsystem));
css->pseudo_subchannel =
kzalloc(sizeof(*css->pseudo_subchannel), GFP_KERNEL);
if (!css->pseudo_subchannel)
return -ENOMEM;
css->pseudo_subchannel->dev.parent = &css->device;
css->pseudo_subchannel->dev.release = css_subchannel_release;
dev_set_name(&css->pseudo_subchannel->dev, "defunct");
ret = cio_create_sch_lock(css->pseudo_subchannel);
if (ret) {
kfree(css->pseudo_subchannel);
return ret;
}
mutex_init(&css->mutex);
css->valid = 1;
css->cssid = nr;
dev_set_name(&css->device, "css%x", nr);
css->device.release = channel_subsystem_release;
tod_high = (u32) (get_clock() >> 32);
css_generate_pgid(css, tod_high);
return 0;
}
static int css_reboot_event(struct notifier_block *this,
unsigned long event,
void *ptr)
{
int ret, i;
ret = NOTIFY_DONE;
for (i = 0; i <= __MAX_CSSID; i++) {
struct channel_subsystem *css;
css = channel_subsystems[i];
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,
};
/*
* Now that the driver core is running, we can setup our channel subsystem.
* The struct subchannel's are created during probing (except for the
* static console subchannel).
*/
static int __init
init_channel_subsystem (void)
{
int ret, i;
ret = chsc_determine_css_characteristics();
if (ret == -ENOMEM)
goto out; /* No need to continue. */
ret = chsc_alloc_sei_area();
if (ret)
goto out;
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;
/* Try to enable MSS. */
ret = chsc_enable_facility(CHSC_SDA_OC_MSS);
switch (ret) {
case 0: /* Success. */
max_ssid = __MAX_SSID;
break;
case -ENOMEM:
goto out_bus;
default:
max_ssid = 0;
}
/* Setup css structure. */
for (i = 0; i <= __MAX_CSSID; i++) {
struct channel_subsystem *css;
css = kmalloc(sizeof(struct channel_subsystem), GFP_KERNEL);
if (!css) {
ret = -ENOMEM;
goto out_unregister;
}
channel_subsystems[i] = css;
ret = setup_css(i);
if (ret) {
kfree(channel_subsystems[i]);
goto out_unregister;
}
ret = device_register(&css->device);
if (ret) {
put_device(&css->device);
goto out_unregister;
}
if (css_chsc_characteristics.secm) {
ret = device_create_file(&css->device,
&dev_attr_cm_enable);
if (ret)
goto out_device;
}
ret = device_register(&css->pseudo_subchannel->dev);
if (ret)
goto out_file;
}
ret = register_reboot_notifier(&css_reboot_notifier);
if (ret)
goto out_unregister;
css_init_done = 1;
/* Enable default isc for I/O subchannels. */
isc_register(IO_SCH_ISC);
for_each_subchannel(__init_channel_subsystem, NULL);
return 0;
out_file:
if (css_chsc_characteristics.secm)
device_remove_file(&channel_subsystems[i]->device,
&dev_attr_cm_enable);
out_device:
device_unregister(&channel_subsystems[i]->device);
out_unregister:
while (i > 0) {
struct channel_subsystem *css;
i--;
css = channel_subsystems[i];
device_unregister(&css->pseudo_subchannel->dev);
css->pseudo_subchannel = NULL;
if (css_chsc_characteristics.secm)
device_remove_file(&css->device,
&dev_attr_cm_enable);
device_unregister(&css->device);
}
out_bus:
bus_unregister(&css_bus_type);
out:
crw_unregister_handler(CRW_RSC_CSS);
chsc_free_sei_area();
kfree(slow_subchannel_set);
pr_alert("The CSS device driver initialization failed with "
"errno=%d\n", ret);
return ret;
}
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;
}
struct bus_type css_bus_type = {
.name = "css",
.match = css_bus_match,
.probe = css_probe,
.remove = css_remove,
.shutdown = css_shutdown,
.uevent = css_uevent,
};
/**
* css_driver_register - register a css driver
* @cdrv: css driver to register
*
* This is mainly a wrapper around driver_register that sets name
* and bus_type in the embedded struct device_driver correctly.
*/
int css_driver_register(struct css_driver *cdrv)
{
cdrv->drv.name = cdrv->name;
cdrv->drv.bus = &css_bus_type;
cdrv->drv.owner = cdrv->owner;
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);
subsys_initcall(init_channel_subsystem);
MODULE_LICENSE("GPL");
EXPORT_SYMBOL(css_bus_type);