// SPDX-License-Identifier: GPL-2.0
/*
* driver for channel subsystem
*
* Copyright IBM Corp. 2002, 2010
*
* Author(s): Arnd Bergmann ([email protected])
* Cornelia Huck ([email protected])
*/
#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/proc_fs.h>
#include <linux/genalloc.h>
#include <linux/dma-mapping.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 const 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 void css_sch_create_locks(struct subchannel *sch)
{
spin_lock_init(&sch->lock);
mutex_init(&sch->reg_mutex);
}
static void css_subchannel_release(struct device *dev)
{
struct subchannel *sch = to_subchannel(dev);
sch->config.intparm = 0;
cio_commit_config(sch);
kfree(sch->driver_override);
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;
css_sch_create_locks(sch);
INIT_WORK(&sch->todo_work, css_sch_todo);
sch->dev.release = &css_subchannel_release;
sch->dev.dma_mask = &sch->dma_mask;
device_initialize(&sch->dev);
/*
* The physical addresses for some of the dma structures that can
* belong to a subchannel need to fit 31 bit width (e.g. ccw).
*/
ret = dma_set_coherent_mask(&sch->dev, DMA_BIT_MASK(31));
if (ret)
goto err;
/*
* But we don't have such restrictions imposed on the stuff that
* is handled by the streaming API.
*/
ret = dma_set_mask(&sch->dev, DMA_BIT_MASK(64));
if (ret)
goto err;
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 sysfs_emit(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 sysfs_emit(buf, "css:t%01X\n", sch->st);
}
static DEVICE_ATTR_RO(modalias);
static ssize_t driver_override_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct subchannel *sch = to_subchannel(dev);
int ret;
ret = driver_set_override(dev, &sch->driver_override, buf, count);
if (ret)
return ret;
return count;
}
static ssize_t driver_override_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct subchannel *sch = to_subchannel(dev);
ssize_t len;
device_lock(dev);
len = sysfs_emit(buf, "%s\n", sch->driver_override);
device_unlock(dev);
return len;
}
static DEVICE_ATTR_RW(driver_override);
static struct attribute *subch_attrs[] = {
&dev_attr_type.attr,
&dev_attr_modalias.attr,
&dev_attr_driver_override.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 sysfs_emit(buf, "%02x %02x %02x\n",
pmcw->pim, pmcw->pam, pmcw->pom);
}
static DEVICE_ATTR_RO(pimpampom);
static ssize_t dev_busid_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct subchannel *sch = to_subchannel(dev);
struct pmcw *pmcw = &sch->schib.pmcw;
if ((pmcw->st == SUBCHANNEL_TYPE_IO && pmcw->dnv) ||
(pmcw->st == SUBCHANNEL_TYPE_MSG && pmcw->w))
return sysfs_emit(buf, "0.%x.%04x\n", sch->schid.ssid,
pmcw->dev);
else
return sysfs_emit(buf, "none\n");
}
static DEVICE_ATTR_RO(dev_busid);
static struct attribute *io_subchannel_type_attrs[] = {
&dev_attr_chpids.attr,
&dev_attr_pimpampom.attr,
&dev_attr_dev_busid.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;
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;
}
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, const void *data)
{
struct subchannel *sch;
struct subchannel_id *schid = (void *)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 DEFINE_SPINLOCK(slow_subchannel_lock);
static DECLARE_WAIT_QUEUE_HEAD(css_eval_wq);
static atomic_t css_eval_scheduled;
static int __init slow_subchannel_init(void)
{
atomic_set(&css_eval_scheduled, 0);
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);
/*
* The loop might take long time for platforms with lots of
* known devices. Allow scheduling here.
*/
cond_resched();
}
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_validpath(struct device *dev, void *data)
{
struct idset *set = data;
struct subchannel *sch = to_subchannel(dev);
struct pmcw *pmcw = &sch->schib.pmcw;
/* Here we want to make sure that we are considering only those subchannels
* which do not have an operational device attached to it. This can be found
* with the help of PAM and POM values of pmcw. OPM provides the information
* about any path which is currently vary-off, so that we should not consider.
*/
if (sch->st == SUBCHANNEL_TYPE_IO &&
(sch->opm & pmcw->pam & pmcw->pom))
idset_sch_del(set, sch->schid);
return 0;
}
static int __unset_online(struct device *dev, void *data)
{
struct idset *set = data;
struct subchannel *sch = to_subchannel(dev);
if (sch->st == SUBCHANNEL_TYPE_IO && sch->config.ena)
idset_sch_del(set, sch->schid);
return 0;
}
void css_schedule_eval_cond(enum css_eval_cond cond, unsigned long delay)
{
unsigned long flags;
struct idset *set;
/* Find unregistered subchannels. */
set = idset_sch_new();
if (!set) {
/* Fallback. */
css_schedule_eval_all();
return;
}
idset_fill(set);
switch (cond) {
case CSS_EVAL_NO_PATH:
bus_for_each_dev(&css_bus_type, NULL, set, __unset_validpath);
break;
case CSS_EVAL_NOT_ONLINE:
bus_for_each_dev(&css_bus_type, NULL, set, __unset_online);
break;
default:
break;
}
/* Apply to slow_subchannel_set. */
spin_lock_irqsave(&slow_subchannel_lock, flags);
idset_add_set(slow_subchannel_set, 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(set);
}
void css_wait_for_slow_path(void)
{
flush_workqueue(cio_work_q);
}
/* Schedule reprobing of all subchannels with no valid operational path. */
void css_schedule_reprobe(void)
{
/* Schedule with a delay to allow merging of subsequent calls. */
css_schedule_eval_cond(CSS_EVAL_NO_PATH, 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->id_valid ? css->cssid : 0;
} 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->id_valid)
return -EINVAL;
return sysfs_emit(buf, "%x\n", css->cssid);
}
static DEVICE_ATTR_RO(real_cssid);
static ssize_t rescan_store(struct device *dev, struct device_attribute *a,
const char *buf, size_t count)
{
CIO_TRACE_EVENT(4, "usr-rescan");
css_schedule_eval_all();
css_complete_work();
return count;
}
static DEVICE_ATTR_WO(rescan);
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 = sysfs_emit(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,
&dev_attr_rescan.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;
/*
* We currently allocate notifier bits with this (using
* css->device as the device argument with the DMA API)
* and are fine with 64 bit addresses.
*/
ret = dma_coerce_mask_and_coherent(&css->device, DMA_BIT_MASK(64));
if (ret) {
kfree(css);
goto out_err;
}
mutex_init(&css->mutex);
ret = chsc_get_cssid_iid(nr, &css->cssid, &css->iid);
if (!ret) {
css->id_valid = true;
pr_info("Partition identifier %01x.%01x\n", css->cssid,
css->iid);
}
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);
css_sch_create_locks(css->pseudo_subchannel);
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,
};
#define CIO_DMA_GFP (GFP_KERNEL | __GFP_ZERO)
static struct gen_pool *cio_dma_pool;
/* Currently cio supports only a single css */
struct device *cio_get_dma_css_dev(void)
{
return &channel_subsystems[0]->device;
}
struct gen_pool *cio_gp_dma_create(struct device *dma_dev, int nr_pages)
{
struct gen_pool *gp_dma;
void *cpu_addr;
dma_addr_t dma_addr;
int i;
gp_dma = gen_pool_create(3, -1);
if (!gp_dma)
return NULL;
for (i = 0; i < nr_pages; ++i) {
cpu_addr = dma_alloc_coherent(dma_dev, PAGE_SIZE, &dma_addr,
CIO_DMA_GFP);
if (!cpu_addr)
return gp_dma;
gen_pool_add_virt(gp_dma, (unsigned long) cpu_addr,
dma_addr, PAGE_SIZE, -1);
}
return gp_dma;
}
static void __gp_dma_free_dma(struct gen_pool *pool,
struct gen_pool_chunk *chunk, void *data)
{
size_t chunk_size = chunk->end_addr - chunk->start_addr + 1;
dma_free_coherent((struct device *) data, chunk_size,
(void *) chunk->start_addr,
(dma_addr_t) chunk->phys_addr);
}
void cio_gp_dma_destroy(struct gen_pool *gp_dma, struct device *dma_dev)
{
if (!gp_dma)
return;
/* this is quite ugly but no better idea */
gen_pool_for_each_chunk(gp_dma, __gp_dma_free_dma, dma_dev);
gen_pool_destroy(gp_dma);
}
static int cio_dma_pool_init(void)
{
/* No need to free up the resources: compiled in */
cio_dma_pool = cio_gp_dma_create(cio_get_dma_css_dev(), 1);
if (!cio_dma_pool)
return -ENOMEM;
return 0;
}
void *__cio_gp_dma_zalloc(struct gen_pool *gp_dma, struct device *dma_dev,
size_t size, dma32_t *dma_handle)
{
dma_addr_t dma_addr;
size_t chunk_size;
void *addr;
if (!gp_dma)
return NULL;
addr = gen_pool_dma_alloc(gp_dma, size, &dma_addr);
while (!addr) {
chunk_size = round_up(size, PAGE_SIZE);
addr = dma_alloc_coherent(dma_dev, chunk_size, &dma_addr, CIO_DMA_GFP);
if (!addr)
return NULL;
gen_pool_add_virt(gp_dma, (unsigned long)addr, dma_addr, chunk_size, -1);
addr = gen_pool_dma_alloc(gp_dma, size, dma_handle ? &dma_addr : NULL);
}
if (dma_handle)
*dma_handle = (__force dma32_t)dma_addr;
return addr;
}
void *cio_gp_dma_zalloc(struct gen_pool *gp_dma, struct device *dma_dev,
size_t size)
{
return __cio_gp_dma_zalloc(gp_dma, dma_dev, size, NULL);
}
void cio_gp_dma_free(struct gen_pool *gp_dma, void *cpu_addr, size_t size)
{
if (!cpu_addr)
return;
memset(cpu_addr, 0, size);
gen_pool_free(gp_dma, (unsigned long) cpu_addr, size);
}
/*
* Allocate dma memory from the css global pool. Intended for memory not
* specific to any single device within the css. The allocated memory
* is not guaranteed to be 31-bit addressable.
*
* Caution: Not suitable for early stuff like console.
*/
void *cio_dma_zalloc(size_t size)
{
return cio_gp_dma_zalloc(cio_dma_pool, cio_get_dma_css_dev(), size);
}
void cio_dma_free(void *cpu_addr, size_t size)
{
cio_gp_dma_free(cio_dma_pool, cpu_addr, size);
}
/*
* 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 = cio_dma_pool_init();
if (ret)
goto out_unregister_rn;
airq_init();
css_init_done = 1;
/* Enable default isc for I/O subchannels. */
isc_register(IO_SCH_ISC);
return 0;
out_unregister_rn:
unregister_reboot_notifier(&css_reboot_notifier);
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);
#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 proc_ops cio_settle_proc_ops = {
.proc_open = nonseekable_open,
.proc_write = cio_settle_write,
.proc_lseek = 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_ops);
if (!entry)
return -ENOMEM;
return 0;
}
device_initcall(cio_settle_init);
#endif /*CONFIG_PROC_FS*/
int sch_is_pseudo_sch(struct subchannel *sch)
{
if (!sch->dev.parent)
return 0;
return sch == to_css(sch->dev.parent)->pseudo_subchannel;
}
static int css_bus_match(struct device *dev, const struct device_driver *drv)
{
struct subchannel *sch = to_subchannel(dev);
const struct css_driver *driver = to_cssdriver(drv);
struct css_device_id *id;
/* When driver_override is set, only bind to the matching driver */
if (sch->driver_override && strcmp(sch->driver_override, drv->name))
return 0;
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 void css_remove(struct device *dev)
{
struct subchannel *sch;
sch = to_subchannel(dev);
if (sch->driver->remove)
sch->driver->remove(sch);
sch->driver = NULL;
}
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(const struct device *dev, struct kobj_uevent_env *env)
{
const 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 const 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.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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