- 根目录:
- drivers
- s390
- cio
- chp.c
/*
* drivers/s390/cio/chp.c
*
* Copyright IBM Corp. 1999,2010
* Author(s): Cornelia Huck (cornelia.huck@de.ibm.com)
* Arnd Bergmann (arndb@de.ibm.com)
* Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
*/
#include <linux/bug.h>
#include <linux/workqueue.h>
#include <linux/spinlock.h>
#include <linux/init.h>
#include <linux/jiffies.h>
#include <linux/wait.h>
#include <linux/mutex.h>
#include <linux/errno.h>
#include <linux/slab.h>
#include <asm/chpid.h>
#include <asm/sclp.h>
#include <asm/crw.h>
#include "cio.h"
#include "css.h"
#include "ioasm.h"
#include "cio_debug.h"
#include "chp.h"
#define to_channelpath(device) container_of(device, struct channel_path, dev)
#define CHP_INFO_UPDATE_INTERVAL 1*HZ
enum cfg_task_t {
cfg_none,
cfg_configure,
cfg_deconfigure
};
/* Map for pending configure tasks. */
static enum cfg_task_t chp_cfg_task[__MAX_CSSID + 1][__MAX_CHPID + 1];
static DEFINE_MUTEX(cfg_lock);
static int cfg_busy;
/* Map for channel-path status. */
static struct sclp_chp_info chp_info;
static DEFINE_MUTEX(info_lock);
/* Time after which channel-path status may be outdated. */
static unsigned long chp_info_expires;
/* Workqueue to perform pending configure tasks. */
static struct workqueue_struct *chp_wq;
static struct work_struct cfg_work;
/* Wait queue for configure completion events. */
static wait_queue_head_t cfg_wait_queue;
/* Set vary state for given chpid. */
static void set_chp_logically_online(struct chp_id chpid, int onoff)
{
chpid_to_chp(chpid)->state = onoff;
}
/* On success return 0 if channel-path is varied offline, 1 if it is varied
* online. Return -ENODEV if channel-path is not registered. */
int chp_get_status(struct chp_id chpid)
{
return (chpid_to_chp(chpid) ? chpid_to_chp(chpid)->state : -ENODEV);
}
/**
* chp_get_sch_opm - return opm for subchannel
* @sch: subchannel
*
* Calculate and return the operational path mask (opm) based on the chpids
* used by the subchannel and the status of the associated channel-paths.
*/
u8 chp_get_sch_opm(struct subchannel *sch)
{
struct chp_id chpid;
int opm;
int i;
opm = 0;
chp_id_init(&chpid);
for (i = 0; i < 8; i++) {
opm <<= 1;
chpid.id = sch->schib.pmcw.chpid[i];
if (chp_get_status(chpid) != 0)
opm |= 1;
}
return opm;
}
EXPORT_SYMBOL_GPL(chp_get_sch_opm);
/**
* chp_is_registered - check if a channel-path is registered
* @chpid: channel-path ID
*
* Return non-zero if a channel-path with the given chpid is registered,
* zero otherwise.
*/
int chp_is_registered(struct chp_id chpid)
{
return chpid_to_chp(chpid) != NULL;
}
/*
* Function: s390_vary_chpid
* Varies the specified chpid online or offline
*/
static int s390_vary_chpid(struct chp_id chpid, int on)
{
char dbf_text[15];
int status;
sprintf(dbf_text, on?"varyon%x.%02x":"varyoff%x.%02x", chpid.cssid,
chpid.id);
CIO_TRACE_EVENT(2, dbf_text);
status = chp_get_status(chpid);
if (!on && !status)
return 0;
set_chp_logically_online(chpid, on);
chsc_chp_vary(chpid, on);
return 0;
}
/*
* Channel measurement related functions
*/
static ssize_t chp_measurement_chars_read(struct file *filp,
struct kobject *kobj,
struct bin_attribute *bin_attr,
char *buf, loff_t off, size_t count)
{
struct channel_path *chp;
struct device *device;
device = container_of(kobj, struct device, kobj);
chp = to_channelpath(device);
if (!chp->cmg_chars)
return 0;
return memory_read_from_buffer(buf, count, &off,
chp->cmg_chars, sizeof(struct cmg_chars));
}
static struct bin_attribute chp_measurement_chars_attr = {
.attr = {
.name = "measurement_chars",
.mode = S_IRUSR,
},
.size = sizeof(struct cmg_chars),
.read = chp_measurement_chars_read,
};
static void chp_measurement_copy_block(struct cmg_entry *buf,
struct channel_subsystem *css,
struct chp_id chpid)
{
void *area;
struct cmg_entry *entry, reference_buf;
int idx;
if (chpid.id < 128) {
area = css->cub_addr1;
idx = chpid.id;
} else {
area = css->cub_addr2;
idx = chpid.id - 128;
}
entry = area + (idx * sizeof(struct cmg_entry));
do {
memcpy(buf, entry, sizeof(*entry));
memcpy(&reference_buf, entry, sizeof(*entry));
} while (reference_buf.values[0] != buf->values[0]);
}
static ssize_t chp_measurement_read(struct file *filp, struct kobject *kobj,
struct bin_attribute *bin_attr,
char *buf, loff_t off, size_t count)
{
struct channel_path *chp;
struct channel_subsystem *css;
struct device *device;
unsigned int size;
device = container_of(kobj, struct device, kobj);
chp = to_channelpath(device);
css = to_css(chp->dev.parent);
size = sizeof(struct cmg_entry);
/* Only allow single reads. */
if (off || count < size)
return 0;
chp_measurement_copy_block((struct cmg_entry *)buf, css, chp->chpid);
count = size;
return count;
}
static struct bin_attribute chp_measurement_attr = {
.attr = {
.name = "measurement",
.mode = S_IRUSR,
},
.size = sizeof(struct cmg_entry),
.read = chp_measurement_read,
};
void chp_remove_cmg_attr(struct channel_path *chp)
{
device_remove_bin_file(&chp->dev, &chp_measurement_chars_attr);
device_remove_bin_file(&chp->dev, &chp_measurement_attr);
}
int chp_add_cmg_attr(struct channel_path *chp)
{
int ret;
ret = device_create_bin_file(&chp->dev, &chp_measurement_chars_attr);
if (ret)
return ret;
ret = device_create_bin_file(&chp->dev, &chp_measurement_attr);
if (ret)
device_remove_bin_file(&chp->dev, &chp_measurement_chars_attr);
return ret;
}
/*
* Files for the channel path entries.
*/
static ssize_t chp_status_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct channel_path *chp = to_channelpath(dev);
int status;
mutex_lock(&chp->lock);
status = chp->state;
mutex_unlock(&chp->lock);
return status ? sprintf(buf, "online\n") : sprintf(buf, "offline\n");
}
static ssize_t chp_status_write(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct channel_path *cp = to_channelpath(dev);
char cmd[10];
int num_args;
int error;
num_args = sscanf(buf, "%5s", cmd);
if (!num_args)
return count;
if (!strnicmp(cmd, "on", 2) || !strcmp(cmd, "1")) {
mutex_lock(&cp->lock);
error = s390_vary_chpid(cp->chpid, 1);
mutex_unlock(&cp->lock);
} else if (!strnicmp(cmd, "off", 3) || !strcmp(cmd, "0")) {
mutex_lock(&cp->lock);
error = s390_vary_chpid(cp->chpid, 0);
mutex_unlock(&cp->lock);
} else
error = -EINVAL;
return error < 0 ? error : count;
}
static DEVICE_ATTR(status, 0644, chp_status_show, chp_status_write);
static ssize_t chp_configure_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct channel_path *cp;
int status;
cp = to_channelpath(dev);
status = chp_info_get_status(cp->chpid);
if (status < 0)
return status;
return snprintf(buf, PAGE_SIZE, "%d\n", status);
}
static int cfg_wait_idle(void);
static ssize_t chp_configure_write(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct channel_path *cp;
int val;
char delim;
if (sscanf(buf, "%d %c", &val, &delim) != 1)
return -EINVAL;
if (val != 0 && val != 1)
return -EINVAL;
cp = to_channelpath(dev);
chp_cfg_schedule(cp->chpid, val);
cfg_wait_idle();
return count;
}
static DEVICE_ATTR(configure, 0644, chp_configure_show, chp_configure_write);
static ssize_t chp_type_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct channel_path *chp = to_channelpath(dev);
u8 type;
mutex_lock(&chp->lock);
type = chp->desc.desc;
mutex_unlock(&chp->lock);
return sprintf(buf, "%x\n", type);
}
static DEVICE_ATTR(type, 0444, chp_type_show, NULL);
static ssize_t chp_cmg_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct channel_path *chp = to_channelpath(dev);
if (!chp)
return 0;
if (chp->cmg == -1) /* channel measurements not available */
return sprintf(buf, "unknown\n");
return sprintf(buf, "%x\n", chp->cmg);
}
static DEVICE_ATTR(cmg, 0444, chp_cmg_show, NULL);
static ssize_t chp_shared_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct channel_path *chp = to_channelpath(dev);
if (!chp)
return 0;
if (chp->shared == -1) /* channel measurements not available */
return sprintf(buf, "unknown\n");
return sprintf(buf, "%x\n", chp->shared);
}
static DEVICE_ATTR(shared, 0444, chp_shared_show, NULL);
static struct attribute *chp_attrs[] = {
&dev_attr_status.attr,
&dev_attr_configure.attr,
&dev_attr_type.attr,
&dev_attr_cmg.attr,
&dev_attr_shared.attr,
NULL,
};
static struct attribute_group chp_attr_group = {
.attrs = chp_attrs,
};
static void chp_release(struct device *dev)
{
struct channel_path *cp;
cp = to_channelpath(dev);
kfree(cp);
}
/**
* chp_new - register a new channel-path
* @chpid - channel-path ID
*
* Create and register data structure representing new channel-path. Return
* zero on success, non-zero otherwise.
*/
int chp_new(struct chp_id chpid)
{
struct channel_path *chp;
int ret;
if (chp_is_registered(chpid))
return 0;
chp = kzalloc(sizeof(struct channel_path), GFP_KERNEL);
if (!chp)
return -ENOMEM;
/* fill in status, etc. */
chp->chpid = chpid;
chp->state = 1;
chp->dev.parent = &channel_subsystems[chpid.cssid]->device;
chp->dev.release = chp_release;
mutex_init(&chp->lock);
/* Obtain channel path description and fill it in. */
ret = chsc_determine_base_channel_path_desc(chpid, &chp->desc);
if (ret)
goto out_free;
if ((chp->desc.flags & 0x80) == 0) {
ret = -ENODEV;
goto out_free;
}
/* Get channel-measurement characteristics. */
if (css_chsc_characteristics.scmc && css_chsc_characteristics.secm) {
ret = chsc_get_channel_measurement_chars(chp);
if (ret)
goto out_free;
} else {
chp->cmg = -1;
}
dev_set_name(&chp->dev, "chp%x.%02x", chpid.cssid, chpid.id);
/* make it known to the system */
ret = device_register(&chp->dev);
if (ret) {
CIO_MSG_EVENT(0, "Could not register chp%x.%02x: %d\n",
chpid.cssid, chpid.id, ret);
put_device(&chp->dev);
goto out;
}
ret = sysfs_create_group(&chp->dev.kobj, &chp_attr_group);
if (ret) {
device_unregister(&chp->dev);
goto out;
}
mutex_lock(&channel_subsystems[chpid.cssid]->mutex);
if (channel_subsystems[chpid.cssid]->cm_enabled) {
ret = chp_add_cmg_attr(chp);
if (ret) {
sysfs_remove_group(&chp->dev.kobj, &chp_attr_group);
device_unregister(&chp->dev);
mutex_unlock(&channel_subsystems[chpid.cssid]->mutex);
goto out;
}
}
channel_subsystems[chpid.cssid]->chps[chpid.id] = chp;
mutex_unlock(&channel_subsystems[chpid.cssid]->mutex);
goto out;
out_free:
kfree(chp);
out:
return ret;
}
/**
* chp_get_chp_desc - return newly allocated channel-path description
* @chpid: channel-path ID
*
* On success return a newly allocated copy of the channel-path description
* data associated with the given channel-path ID. Return %NULL on error.
*/
void *chp_get_chp_desc(struct chp_id chpid)
{
struct channel_path *chp;
struct channel_path_desc *desc;
chp = chpid_to_chp(chpid);
if (!chp)
return NULL;
desc = kmalloc(sizeof(struct channel_path_desc), GFP_KERNEL);
if (!desc)
return NULL;
mutex_lock(&chp->lock);
memcpy(desc, &chp->desc, sizeof(struct channel_path_desc));
mutex_unlock(&chp->lock);
return desc;
}
/**
* chp_process_crw - process channel-path status change
* @crw0: channel report-word to handler
* @crw1: second channel-report word (always NULL)
* @overflow: crw overflow indication
*
* Handle channel-report-words indicating that the status of a channel-path
* has changed.
*/
static void chp_process_crw(struct crw *crw0, struct crw *crw1,
int overflow)
{
struct chp_id chpid;
if (overflow) {
css_schedule_eval_all();
return;
}
CIO_CRW_EVENT(2, "CRW reports slct=%d, oflw=%d, "
"chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n",
crw0->slct, crw0->oflw, crw0->chn, crw0->rsc, crw0->anc,
crw0->erc, crw0->rsid);
/*
* Check for solicited machine checks. These are
* created by reset channel path and need not be
* handled here.
*/
if (crw0->slct) {
CIO_CRW_EVENT(2, "solicited machine check for "
"channel path %02X\n", crw0->rsid);
return;
}
chp_id_init(&chpid);
chpid.id = crw0->rsid;
switch (crw0->erc) {
case CRW_ERC_IPARM: /* Path has come. */
if (!chp_is_registered(chpid))
chp_new(chpid);
chsc_chp_online(chpid);
break;
case CRW_ERC_PERRI: /* Path has gone. */
case CRW_ERC_PERRN:
chsc_chp_offline(chpid);
break;
default:
CIO_CRW_EVENT(2, "Don't know how to handle erc=%x\n",
crw0->erc);
}
}
int chp_ssd_get_mask(struct chsc_ssd_info *ssd, struct chp_link *link)
{
int i;
int mask;
for (i = 0; i < 8; i++) {
mask = 0x80 >> i;
if (!(ssd->path_mask & mask))
continue;
if (!chp_id_is_equal(&ssd->chpid[i], &link->chpid))
continue;
if ((ssd->fla_valid_mask & mask) &&
((ssd->fla[i] & link->fla_mask) != link->fla))
continue;
return mask;
}
return 0;
}
EXPORT_SYMBOL_GPL(chp_ssd_get_mask);
static inline int info_bit_num(struct chp_id id)
{
return id.id + id.cssid * (__MAX_CHPID + 1);
}
/* Force chp_info refresh on next call to info_validate(). */
static void info_expire(void)
{
mutex_lock(&info_lock);
chp_info_expires = jiffies - 1;
mutex_unlock(&info_lock);
}
/* Ensure that chp_info is up-to-date. */
static int info_update(void)
{
int rc;
mutex_lock(&info_lock);
rc = 0;
if (time_after(jiffies, chp_info_expires)) {
/* Data is too old, update. */
rc = sclp_chp_read_info(&chp_info);
chp_info_expires = jiffies + CHP_INFO_UPDATE_INTERVAL ;
}
mutex_unlock(&info_lock);
return rc;
}
/**
* chp_info_get_status - retrieve configure status of a channel-path
* @chpid: channel-path ID
*
* On success, return 0 for standby, 1 for configured, 2 for reserved,
* 3 for not recognized. Return negative error code on error.
*/
int chp_info_get_status(struct chp_id chpid)
{
int rc;
int bit;
rc = info_update();
if (rc)
return rc;
bit = info_bit_num(chpid);
mutex_lock(&info_lock);
if (!chp_test_bit(chp_info.recognized, bit))
rc = CHP_STATUS_NOT_RECOGNIZED;
else if (chp_test_bit(chp_info.configured, bit))
rc = CHP_STATUS_CONFIGURED;
else if (chp_test_bit(chp_info.standby, bit))
rc = CHP_STATUS_STANDBY;
else
rc = CHP_STATUS_RESERVED;
mutex_unlock(&info_lock);
return rc;
}
/* Return configure task for chpid. */
static enum cfg_task_t cfg_get_task(struct chp_id chpid)
{
return chp_cfg_task[chpid.cssid][chpid.id];
}
/* Set configure task for chpid. */
static void cfg_set_task(struct chp_id chpid, enum cfg_task_t cfg)
{
chp_cfg_task[chpid.cssid][chpid.id] = cfg;
}
/* Perform one configure/deconfigure request. Reschedule work function until
* last request. */
static void cfg_func(struct work_struct *work)
{
struct chp_id chpid;
enum cfg_task_t t;
int rc;
mutex_lock(&cfg_lock);
t = cfg_none;
chp_id_for_each(&chpid) {
t = cfg_get_task(chpid);
if (t != cfg_none) {
cfg_set_task(chpid, cfg_none);
break;
}
}
mutex_unlock(&cfg_lock);
switch (t) {
case cfg_configure:
rc = sclp_chp_configure(chpid);
if (rc)
CIO_MSG_EVENT(2, "chp: sclp_chp_configure(%x.%02x)="
"%d\n", chpid.cssid, chpid.id, rc);
else {
info_expire();
chsc_chp_online(chpid);
}
break;
case cfg_deconfigure:
rc = sclp_chp_deconfigure(chpid);
if (rc)
CIO_MSG_EVENT(2, "chp: sclp_chp_deconfigure(%x.%02x)="
"%d\n", chpid.cssid, chpid.id, rc);
else {
info_expire();
chsc_chp_offline(chpid);
}
break;
case cfg_none:
/* Get updated information after last change. */
info_update();
mutex_lock(&cfg_lock);
cfg_busy = 0;
mutex_unlock(&cfg_lock);
wake_up_interruptible(&cfg_wait_queue);
return;
}
queue_work(chp_wq, &cfg_work);
}
/**
* chp_cfg_schedule - schedule chpid configuration request
* @chpid - channel-path ID
* @configure - Non-zero for configure, zero for deconfigure
*
* Schedule a channel-path configuration/deconfiguration request.
*/
void chp_cfg_schedule(struct chp_id chpid, int configure)
{
CIO_MSG_EVENT(2, "chp_cfg_sched%x.%02x=%d\n", chpid.cssid, chpid.id,
configure);
mutex_lock(&cfg_lock);
cfg_set_task(chpid, configure ? cfg_configure : cfg_deconfigure);
cfg_busy = 1;
mutex_unlock(&cfg_lock);
queue_work(chp_wq, &cfg_work);
}
/**
* chp_cfg_cancel_deconfigure - cancel chpid deconfiguration request
* @chpid - channel-path ID
*
* Cancel an active channel-path deconfiguration request if it has not yet
* been performed.
*/
void chp_cfg_cancel_deconfigure(struct chp_id chpid)
{
CIO_MSG_EVENT(2, "chp_cfg_cancel:%x.%02x\n", chpid.cssid, chpid.id);
mutex_lock(&cfg_lock);
if (cfg_get_task(chpid) == cfg_deconfigure)
cfg_set_task(chpid, cfg_none);
mutex_unlock(&cfg_lock);
}
static int cfg_wait_idle(void)
{
if (wait_event_interruptible(cfg_wait_queue, !cfg_busy))
return -ERESTARTSYS;
return 0;
}
static int __init chp_init(void)
{
struct chp_id chpid;
int ret;
ret = crw_register_handler(CRW_RSC_CPATH, chp_process_crw);
if (ret)
return ret;
chp_wq = create_singlethread_workqueue("cio_chp");
if (!chp_wq) {
crw_unregister_handler(CRW_RSC_CPATH);
return -ENOMEM;
}
INIT_WORK(&cfg_work, cfg_func);
init_waitqueue_head(&cfg_wait_queue);
if (info_update())
return 0;
/* Register available channel-paths. */
chp_id_for_each(&chpid) {
if (chp_info_get_status(chpid) != CHP_STATUS_NOT_RECOGNIZED)
chp_new(chpid);
}
return 0;
}
subsys_initcall(chp_init);