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author | Sebastian Ott <sebott@linux.vnet.ibm.com> | 2012-08-28 16:48:16 +0200 |
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committer | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2012-09-26 15:45:00 +0200 |
commit | eadb86ab80545d04a0ee576e92ba4447621cdb02 (patch) | |
tree | fa9903cd696ea67d244dab55a1fdb71658208cfa /drivers/s390/cio/eadm_sch.c | |
parent | s390: add scm notification (diff) | |
download | linux-eadb86ab80545d04a0ee576e92ba4447621cdb02.tar.xz linux-eadb86ab80545d04a0ee576e92ba4447621cdb02.zip |
s390/cio: add eadm subchannel driver
This driver allows usage of EADM subchannels. EADM subchannels
act as a communication vehicle for SCM increments.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'drivers/s390/cio/eadm_sch.c')
-rw-r--r-- | drivers/s390/cio/eadm_sch.c | 398 |
1 files changed, 398 insertions, 0 deletions
diff --git a/drivers/s390/cio/eadm_sch.c b/drivers/s390/cio/eadm_sch.c new file mode 100644 index 000000000000..3fc882f66689 --- /dev/null +++ b/drivers/s390/cio/eadm_sch.c @@ -0,0 +1,398 @@ +/* + * Driver for s390 eadm subchannels + * + * Copyright IBM Corp. 2012 + * Author(s): Sebastian Ott <sebott@linux.vnet.ibm.com> + */ + +#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 (5 * 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 (level > 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 = (struct irb *)&S390_lowcore.irb; + int error = 0; + + EADM_LOG(6, "irq"); + EADM_LOG_HEX(6, irb, sizeof(*irb)); + + 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; +} + +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; +} + +static 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; +} + +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) +{ + int ret; + + do { + spin_lock_irq(sch->lock); + ret = cio_disable_subchannel(sch); + spin_unlock_irq(sch->lock); + } while (ret == -EBUSY); +} + +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 struct eadm_ops eadm_ops = { + .eadm_start = eadm_start_aob, + .owner = THIS_MODULE, +}; + +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; + + register_eadm_ops(&eadm_ops); + return ret; + +cleanup: + isc_unregister(EADM_SCH_ISC); + debug_unregister(eadm_debug); + return ret; +} + +static void __exit eadm_sch_exit(void) +{ + unregister_eadm_ops(&eadm_ops); + 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); |