// SPDX-License-Identifier: GPL-2.0
/*
* Driver for s390 eadm subchannels
*
* Copyright IBM Corp. 2012
* Author(s): Sebastian Ott <[email protected]>
*/
#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 <linux/io.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)
{
debug_event(eadm_debug, level, data, length);
}
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 = virt_to_dma32(aob);
orb->eadm.intparm = (u32)virt_to_phys(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(struct timer_list *t)
{
struct eadm_private *private = from_timer(private, t, timer);
struct subchannel *sch = private->sch;
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);
else
mod_timer(&private->timer, jiffies + expires);
}
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);
blk_status_t error = BLK_STS_OK;
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 = BLK_STS_IOERR;
if (scsw->fctl & SCSW_FCTL_CLEAR_FUNC)
error = BLK_STS_TIMEOUT;
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(dma32_to_virt(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);
timer_setup(&private->timer, eadm_subchannel_timeout, 0);
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)virt_to_phys(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);
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 void 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);
}
static void eadm_subchannel_shutdown(struct subchannel *sch)
{
eadm_quiesce(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;
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 0;
}
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,
};
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);
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