#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 <asm/errno.h>
+#include <asm/chpid.h>
+#include <asm/sclp.h>
-#include "chpid.h"
#include "cio.h"
#include "css.h"
#include "ioasm.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+/* Time after which channel-path status may be outdated.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)
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 = container_of(dev, struct channel_path, 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 = container_of(dev, struct channel_path, 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)
{
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,
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;
return 0;
}
}
+
+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);
projects / linux-2.6-omap-h63xx.git / blobdiff