linux/drivers/s390/cio/chp.c

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/*
* drivers/s390/cio/chp.c
*
* Copyright IBM Corp. 1999,2007
* 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 <asm/chpid.h>
#include <asm/sclp.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/* Time after which channel-path status may be outdated.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;
/* Return channel_path struct for given chpid. */
static inline struct channel_path *chpid_to_chp(struct chp_id chpid)
{
return channel_subsystems[chpid.cssid]->chps[chpid.id];
}
/* 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 succes 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;
}
/**
* 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) {
printk(KERN_ERR "cio: chpid %x.%02x is already offline\n",
chpid.cssid, chpid.id);
return -EINVAL;
}
set_chp_logically_online(chpid, on);
chsc_chp_vary(chpid, on);
return 0;
}
/*
* Channel measurement related functions
*/
sysfs: add parameter "struct bin_attribute *" in .read/.write methods for sysfs binary attributes Well, first of all, I don't want to change so many files either. What I do: Adding a new parameter "struct bin_attribute *" in the .read/.write methods for the sysfs binary attributes. In fact, only the four lines change in fs/sysfs/bin.c and include/linux/sysfs.h do the real work. But I have to update all the files that use binary attributes to make them compatible with the new .read and .write methods. I'm not sure if I missed any. :( Why I do this: For a sysfs attribute, we can get a pointer pointing to the struct attribute in the .show/.store method, while we can't do this for the binary attributes. I don't know why this is different, but this does make it not so handy to use the binary attributes as the regular ones. So I think this patch is reasonable. :) Who benefits from it: The patch that exposes ACPI tables in sysfs requires such an improvement. All the table binary attributes share the same .read method. Parameter "struct bin_attribute *" is used to get the table signature and instance number which are used to distinguish different ACPI table binary attributes. Without this parameter, we need to offer different .read methods for different ACPI table binary attributes. This is impossible as there are various ACPI tables on different platforms, and we don't know what they are until they are loaded. Signed-off-by: Zhang Rui <rui.zhang@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-06-09 05:57:22 +00:00
static ssize_t chp_measurement_chars_read(struct kobject *kobj,
struct bin_attribute *bin_attr,
char *buf, loff_t off, size_t count)
{
struct channel_path *chp;
struct device *device;
unsigned int size;
device = container_of(kobj, struct device, kobj);
chp = to_channelpath(device);
if (!chp->cmg_chars)
return 0;
size = sizeof(struct cmg_chars);
if (off > size)
return 0;
if (off + count > size)
count = size - off;
memcpy(buf, chp->cmg_chars + off, count);
return count;
}
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]);
}
sysfs: add parameter "struct bin_attribute *" in .read/.write methods for sysfs binary attributes Well, first of all, I don't want to change so many files either. What I do: Adding a new parameter "struct bin_attribute *" in the .read/.write methods for the sysfs binary attributes. In fact, only the four lines change in fs/sysfs/bin.c and include/linux/sysfs.h do the real work. But I have to update all the files that use binary attributes to make them compatible with the new .read and .write methods. I'm not sure if I missed any. :( Why I do this: For a sysfs attribute, we can get a pointer pointing to the struct attribute in the .show/.store method, while we can't do this for the binary attributes. I don't know why this is different, but this does make it not so handy to use the binary attributes as the regular ones. So I think this patch is reasonable. :) Who benefits from it: The patch that exposes ACPI tables in sysfs requires such an improvement. All the table binary attributes share the same .read method. Parameter "struct bin_attribute *" is used to get the table signature and instance number which are used to distinguish different ACPI table binary attributes. Without this parameter, we need to offer different .read methods for different ACPI table binary attributes. This is impossible as there are various ACPI tables on different platforms, and we don't know what they are until they are loaded. Signed-off-by: Zhang Rui <rui.zhang@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-06-09 05:57:22 +00:00
static ssize_t chp_measurement_read(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);
if (!chp)
return 0;
return (chp_get_status(chp->chpid) ? 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"))
error = s390_vary_chpid(cp->chpid, 1);
else if (!strnicmp(cmd, "off", 3) || !strcmp(cmd, "0"))
error = s390_vary_chpid(cp->chpid, 0);
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);
if (!chp)
return 0;
return sprintf(buf, "%x\n", chp->desc.desc);
}
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;
snprintf(chp->dev.bus_id, BUS_ID_SIZE, "chp%x.%02x", chpid.cssid,
chpid.id);
/* Obtain channel path description and fill it in. */
ret = chsc_determine_channel_path_description(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_characteristics_avail && css_chsc_characteristics.scmc
&& css_chsc_characteristics.secm) {
ret = chsc_get_channel_measurement_chars(chp);
if (ret)
goto out_free;
} else {
chp->cmg = -1;
}
/* 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);
goto out_free;
}
ret = sysfs_create_group(&chp->dev.kobj, &chp_attr_group);
if (ret) {
device_unregister(&chp->dev);
goto out_free;
}
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_free;
}
}
channel_subsystems[chpid.cssid]->chps[chpid.id] = chp;
mutex_unlock(&channel_subsystems[chpid.cssid]->mutex);
return ret;
out_free:
kfree(chp);
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;
memcpy(desc, &chp->desc, sizeof(struct channel_path_desc));
return desc;
}
/**
* chp_process_crw - process channel-path status change
* @id: channel-path ID number
* @status: non-zero if channel-path has become available, zero otherwise
*
* Handle channel-report-words indicating that the status of a channel-path
* has changed.
*/
void chp_process_crw(int id, int status)
{
struct chp_id chpid;
chp_id_init(&chpid);
chpid.id = id;
if (status) {
if (!chp_is_registered(chpid))
chp_new(chpid);
chsc_chp_online(chpid);
} else
chsc_chp_offline(chpid);
}
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;
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:
sclp_chp_configure(chpid);
info_expire();
chsc_chp_online(chpid);
break;
case cfg_deconfigure:
sclp_chp_deconfigure(chpid);
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;
chp_wq = create_singlethread_workqueue("cio_chp");
if (!chp_wq)
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);