--- /dev/null
+/*
+ * Driver for s390 eadm subchannels
+ *
+ * Copyright IBM Corp. 2012
+ * Author(s): Sebastian Ott <sebott@linux.vnet.ibm.com>
+ */
+
+#include <linux/kernel_stat.h>
+#include <linux/completion.h>
+#include <linux/workqueue.h>
+#include <linux/spinlock.h>
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/timer.h>
+#include <linux/slab.h>
+#include <linux/list.h>
+
+#include <asm/css_chars.h>
+#include <asm/debug.h>
+#include <asm/isc.h>
+#include <asm/cio.h>
+#include <asm/scsw.h>
+#include <asm/eadm.h>
+
+#include "eadm_sch.h"
+#include "ioasm.h"
+#include "cio.h"
+#include "css.h"
+#include "orb.h"
+
+MODULE_DESCRIPTION("driver for s390 eadm subchannels");
+MODULE_LICENSE("GPL");
+
+#define EADM_TIMEOUT (7 * HZ)
+static DEFINE_SPINLOCK(list_lock);
+static LIST_HEAD(eadm_list);
+
+static debug_info_t *eadm_debug;
+
+#define EADM_LOG(imp, txt) do { \
+ debug_text_event(eadm_debug, imp, txt); \
+ } while (0)
+
+static void EADM_LOG_HEX(int level, void *data, int length)
+{
+ if (!debug_level_enabled(eadm_debug, level))
+ return;
+ while (length > 0) {
+ debug_event(eadm_debug, level, data, length);
+ length -= eadm_debug->buf_size;
+ data += eadm_debug->buf_size;
+ }
+}
+
+static void orb_init(union orb *orb)
+{
+ memset(orb, 0, sizeof(union orb));
+ orb->eadm.compat1 = 1;
+ orb->eadm.compat2 = 1;
+ orb->eadm.fmt = 1;
+ orb->eadm.x = 1;
+}
+
+static int eadm_subchannel_start(struct subchannel *sch, struct aob *aob)
+{
+ union orb *orb = &get_eadm_private(sch)->orb;
+ int cc;
+
+ orb_init(orb);
+ orb->eadm.aob = (u32)__pa(aob);
+ orb->eadm.intparm = (u32)(addr_t)sch;
+ orb->eadm.key = PAGE_DEFAULT_KEY >> 4;
+
+ EADM_LOG(6, "start");
+ EADM_LOG_HEX(6, &sch->schid, sizeof(sch->schid));
+
+ cc = ssch(sch->schid, orb);
+ switch (cc) {
+ case 0:
+ sch->schib.scsw.eadm.actl |= SCSW_ACTL_START_PEND;
+ break;
+ case 1: /* status pending */
+ case 2: /* busy */
+ return -EBUSY;
+ case 3: /* not operational */
+ return -ENODEV;
+ }
+ return 0;
+}
+
+static int eadm_subchannel_clear(struct subchannel *sch)
+{
+ int cc;
+
+ cc = csch(sch->schid);
+ if (cc)
+ return -ENODEV;
+
+ sch->schib.scsw.eadm.actl |= SCSW_ACTL_CLEAR_PEND;
+ return 0;
+}
+
+static void eadm_subchannel_timeout(unsigned long data)
+{
+ struct subchannel *sch = (struct subchannel *) data;
+
+ spin_lock_irq(sch->lock);
+ EADM_LOG(1, "timeout");
+ EADM_LOG_HEX(1, &sch->schid, sizeof(sch->schid));
+ if (eadm_subchannel_clear(sch))
+ EADM_LOG(0, "clear failed");
+ spin_unlock_irq(sch->lock);
+}
+
+static void eadm_subchannel_set_timeout(struct subchannel *sch, int expires)
+{
+ struct eadm_private *private = get_eadm_private(sch);
+
+ if (expires == 0) {
+ del_timer(&private->timer);
+ return;
+ }
+ if (timer_pending(&private->timer)) {
+ if (mod_timer(&private->timer, jiffies + expires))
+ return;
+ }
+ private->timer.function = eadm_subchannel_timeout;
+ private->timer.data = (unsigned long) sch;
+ private->timer.expires = jiffies + expires;
+ add_timer(&private->timer);
+}
+
+static void eadm_subchannel_irq(struct subchannel *sch)
+{
+ struct eadm_private *private = get_eadm_private(sch);
+ struct eadm_scsw *scsw = &sch->schib.scsw.eadm;
+ struct irb *irb = this_cpu_ptr(&cio_irb);
+ int error = 0;
+
+ EADM_LOG(6, "irq");
+ EADM_LOG_HEX(6, irb, sizeof(*irb));
+
+ inc_irq_stat(IRQIO_ADM);
+
+ if ((scsw->stctl & (SCSW_STCTL_ALERT_STATUS | SCSW_STCTL_STATUS_PEND))
+ && scsw->eswf == 1 && irb->esw.eadm.erw.r)
+ error = -EIO;
+
+ if (scsw->fctl & SCSW_FCTL_CLEAR_FUNC)
+ error = -ETIMEDOUT;
+
+ eadm_subchannel_set_timeout(sch, 0);
+
+ if (private->state != EADM_BUSY) {
+ EADM_LOG(1, "irq unsol");
+ EADM_LOG_HEX(1, irb, sizeof(*irb));
+ private->state = EADM_NOT_OPER;
+ css_sched_sch_todo(sch, SCH_TODO_EVAL);
+ return;
+ }
+ scm_irq_handler((struct aob *)(unsigned long)scsw->aob, error);
+ private->state = EADM_IDLE;
+
+ if (private->completion)
+ complete(private->completion);
+}
+
+static struct subchannel *eadm_get_idle_sch(void)
+{
+ struct eadm_private *private;
+ struct subchannel *sch;
+ unsigned long flags;
+
+ spin_lock_irqsave(&list_lock, flags);
+ list_for_each_entry(private, &eadm_list, head) {
+ sch = private->sch;
+ spin_lock(sch->lock);
+ if (private->state == EADM_IDLE) {
+ private->state = EADM_BUSY;
+ list_move_tail(&private->head, &eadm_list);
+ spin_unlock(sch->lock);
+ spin_unlock_irqrestore(&list_lock, flags);
+
+ return sch;
+ }
+ spin_unlock(sch->lock);
+ }
+ spin_unlock_irqrestore(&list_lock, flags);
+
+ return NULL;
+}
+
+int eadm_start_aob(struct aob *aob)
+{
+ struct eadm_private *private;
+ struct subchannel *sch;
+ unsigned long flags;
+ int ret;
+
+ sch = eadm_get_idle_sch();
+ if (!sch)
+ return -EBUSY;
+
+ spin_lock_irqsave(sch->lock, flags);
+ eadm_subchannel_set_timeout(sch, EADM_TIMEOUT);
+ ret = eadm_subchannel_start(sch, aob);
+ if (!ret)
+ goto out_unlock;
+
+ /* Handle start subchannel failure. */
+ eadm_subchannel_set_timeout(sch, 0);
+ private = get_eadm_private(sch);
+ private->state = EADM_NOT_OPER;
+ css_sched_sch_todo(sch, SCH_TODO_EVAL);
+
+out_unlock:
+ spin_unlock_irqrestore(sch->lock, flags);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(eadm_start_aob);
+
+static int eadm_subchannel_probe(struct subchannel *sch)
+{
+ struct eadm_private *private;
+ int ret;
+
+ private = kzalloc(sizeof(*private), GFP_KERNEL | GFP_DMA);
+ if (!private)
+ return -ENOMEM;
+
+ INIT_LIST_HEAD(&private->head);
+ init_timer(&private->timer);
+
+ spin_lock_irq(sch->lock);
+ set_eadm_private(sch, private);
+ private->state = EADM_IDLE;
+ private->sch = sch;
+ sch->isc = EADM_SCH_ISC;
+ ret = cio_enable_subchannel(sch, (u32)(unsigned long)sch);
+ if (ret) {
+ set_eadm_private(sch, NULL);
+ spin_unlock_irq(sch->lock);
+ kfree(private);
+ goto out;
+ }
+ spin_unlock_irq(sch->lock);
+
+ spin_lock_irq(&list_lock);
+ list_add(&private->head, &eadm_list);
+ spin_unlock_irq(&list_lock);
+
+ if (dev_get_uevent_suppress(&sch->dev)) {
+ dev_set_uevent_suppress(&sch->dev, 0);
+ kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
+ }
+out:
+ return ret;
+}
+
+static void eadm_quiesce(struct subchannel *sch)
+{
+ struct eadm_private *private = get_eadm_private(sch);
+ DECLARE_COMPLETION_ONSTACK(completion);
+ int ret;
+
+ spin_lock_irq(sch->lock);
+ if (private->state != EADM_BUSY)
+ goto disable;
+
+ if (eadm_subchannel_clear(sch))
+ goto disable;
+
+ private->completion = &completion;
+ spin_unlock_irq(sch->lock);
+
+ wait_for_completion_io(&completion);
+
+ spin_lock_irq(sch->lock);
+ private->completion = NULL;
+
+disable:
+ eadm_subchannel_set_timeout(sch, 0);
+ do {
+ ret = cio_disable_subchannel(sch);
+ } while (ret == -EBUSY);
+
+ spin_unlock_irq(sch->lock);
+}
+
+static int eadm_subchannel_remove(struct subchannel *sch)
+{
+ struct eadm_private *private = get_eadm_private(sch);
+
+ spin_lock_irq(&list_lock);
+ list_del(&private->head);
+ spin_unlock_irq(&list_lock);
+
+ eadm_quiesce(sch);
+
+ spin_lock_irq(sch->lock);
+ set_eadm_private(sch, NULL);
+ spin_unlock_irq(sch->lock);
+
+ kfree(private);
+
+ return 0;
+}
+
+static void eadm_subchannel_shutdown(struct subchannel *sch)
+{
+ eadm_quiesce(sch);
+}
+
+static int eadm_subchannel_freeze(struct subchannel *sch)
+{
+ return cio_disable_subchannel(sch);
+}
+
+static int eadm_subchannel_restore(struct subchannel *sch)
+{
+ return cio_enable_subchannel(sch, (u32)(unsigned long)sch);
+}
+
+/**
+ * eadm_subchannel_sch_event - process subchannel event
+ * @sch: subchannel
+ * @process: non-zero if function is called in process context
+ *
+ * An unspecified event occurred for this subchannel. Adjust data according
+ * to the current operational state of the subchannel. Return zero when the
+ * event has been handled sufficiently or -EAGAIN when this function should
+ * be called again in process context.
+ */
+static int eadm_subchannel_sch_event(struct subchannel *sch, int process)
+{
+ struct eadm_private *private;
+ unsigned long flags;
+ int ret = 0;
+
+ spin_lock_irqsave(sch->lock, flags);
+ if (!device_is_registered(&sch->dev))
+ goto out_unlock;
+
+ if (work_pending(&sch->todo_work))
+ goto out_unlock;
+
+ if (cio_update_schib(sch)) {
+ css_sched_sch_todo(sch, SCH_TODO_UNREG);
+ goto out_unlock;
+ }
+ private = get_eadm_private(sch);
+ if (private->state == EADM_NOT_OPER)
+ private->state = EADM_IDLE;
+
+out_unlock:
+ spin_unlock_irqrestore(sch->lock, flags);
+
+ return ret;
+}
+
+static struct css_device_id eadm_subchannel_ids[] = {
+ { .match_flags = 0x1, .type = SUBCHANNEL_TYPE_ADM, },
+ { /* end of list */ },
+};
+MODULE_DEVICE_TABLE(css, eadm_subchannel_ids);
+
+static struct css_driver eadm_subchannel_driver = {
+ .drv = {
+ .name = "eadm_subchannel",
+ .owner = THIS_MODULE,
+ },
+ .subchannel_type = eadm_subchannel_ids,
+ .irq = eadm_subchannel_irq,
+ .probe = eadm_subchannel_probe,
+ .remove = eadm_subchannel_remove,
+ .shutdown = eadm_subchannel_shutdown,
+ .sch_event = eadm_subchannel_sch_event,
+ .freeze = eadm_subchannel_freeze,
+ .thaw = eadm_subchannel_restore,
+ .restore = eadm_subchannel_restore,
+};
+
+static int __init eadm_sch_init(void)
+{
+ int ret;
+
+ if (!css_general_characteristics.eadm)
+ return -ENXIO;
+
+ eadm_debug = debug_register("eadm_log", 16, 1, 16);
+ if (!eadm_debug)
+ return -ENOMEM;
+
+ debug_register_view(eadm_debug, &debug_hex_ascii_view);
+ debug_set_level(eadm_debug, 2);
+
+ isc_register(EADM_SCH_ISC);
+ ret = css_driver_register(&eadm_subchannel_driver);
+ if (ret)
+ goto cleanup;
+
+ return ret;
+
+cleanup:
+ isc_unregister(EADM_SCH_ISC);
+ debug_unregister(eadm_debug);
+ return ret;
+}
+
+static void __exit eadm_sch_exit(void)
+{
+ css_driver_unregister(&eadm_subchannel_driver);
+ isc_unregister(EADM_SCH_ISC);
+ debug_unregister(eadm_debug);
+}
+module_init(eadm_sch_init);
+module_exit(eadm_sch_exit);
Code Review / kvmfornfv.git / blobdiff