162 lines
4.9 KiB
C
162 lines
4.9 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
|
|
/*
|
|
* Copyright 2010 2011 Mark Nelson and Tseng-Hui (Frank) Lin, IBM Corporation
|
|
*/
|
|
|
|
#include <linux/errno.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/export.h>
|
|
#include <linux/irq.h>
|
|
#include <linux/interrupt.h>
|
|
#include <linux/of.h>
|
|
#include <linux/list.h>
|
|
#include <linux/notifier.h>
|
|
|
|
#include <asm/machdep.h>
|
|
#include <asm/rtas.h>
|
|
#include <asm/irq.h>
|
|
#include <asm/io_event_irq.h>
|
|
|
|
#include "pseries.h"
|
|
|
|
/*
|
|
* IO event interrupt is a mechanism provided by RTAS to return
|
|
* information about hardware error and non-error events. Device
|
|
* drivers can register their event handlers to receive events.
|
|
* Device drivers are expected to use atomic_notifier_chain_register()
|
|
* and atomic_notifier_chain_unregister() to register and unregister
|
|
* their event handlers. Since multiple IO event types and scopes
|
|
* share an IO event interrupt, the event handlers are called one
|
|
* by one until the IO event is claimed by one of the handlers.
|
|
* The event handlers are expected to return NOTIFY_OK if the
|
|
* event is handled by the event handler or NOTIFY_DONE if the
|
|
* event does not belong to the handler.
|
|
*
|
|
* Usage:
|
|
*
|
|
* Notifier function:
|
|
* #include <asm/io_event_irq.h>
|
|
* int event_handler(struct notifier_block *nb, unsigned long val, void *data) {
|
|
* p = (struct pseries_io_event_sect_data *) data;
|
|
* if (! is_my_event(p->scope, p->event_type)) return NOTIFY_DONE;
|
|
* :
|
|
* :
|
|
* return NOTIFY_OK;
|
|
* }
|
|
* struct notifier_block event_nb = {
|
|
* .notifier_call = event_handler,
|
|
* }
|
|
*
|
|
* Registration:
|
|
* atomic_notifier_chain_register(&pseries_ioei_notifier_list, &event_nb);
|
|
*
|
|
* Unregistration:
|
|
* atomic_notifier_chain_unregister(&pseries_ioei_notifier_list, &event_nb);
|
|
*/
|
|
|
|
ATOMIC_NOTIFIER_HEAD(pseries_ioei_notifier_list);
|
|
EXPORT_SYMBOL_GPL(pseries_ioei_notifier_list);
|
|
|
|
static int ioei_check_exception_token;
|
|
|
|
static char ioei_rtas_buf[RTAS_DATA_BUF_SIZE] __cacheline_aligned;
|
|
|
|
/**
|
|
* Find the data portion of an IO Event section from event log.
|
|
* @elog: RTAS error/event log.
|
|
*
|
|
* Return:
|
|
* pointer to a valid IO event section data. NULL if not found.
|
|
*/
|
|
static struct pseries_io_event * ioei_find_event(struct rtas_error_log *elog)
|
|
{
|
|
struct pseries_errorlog *sect;
|
|
|
|
/* We should only ever get called for io-event interrupts, but if
|
|
* we do get called for another type then something went wrong so
|
|
* make some noise about it.
|
|
* RTAS_TYPE_IO only exists in extended event log version 6 or later.
|
|
* No need to check event log version.
|
|
*/
|
|
if (unlikely(rtas_error_type(elog) != RTAS_TYPE_IO)) {
|
|
printk_once(KERN_WARNING"io_event_irq: Unexpected event type %d",
|
|
rtas_error_type(elog));
|
|
return NULL;
|
|
}
|
|
|
|
sect = get_pseries_errorlog(elog, PSERIES_ELOG_SECT_ID_IO_EVENT);
|
|
if (unlikely(!sect)) {
|
|
printk_once(KERN_WARNING "io_event_irq: RTAS extended event "
|
|
"log does not contain an IO Event section. "
|
|
"Could be a bug in system firmware!\n");
|
|
return NULL;
|
|
}
|
|
return (struct pseries_io_event *) §->data;
|
|
}
|
|
|
|
/*
|
|
* PAPR:
|
|
* - check-exception returns the first found error or event and clear that
|
|
* error or event so it is reported once.
|
|
* - Each interrupt returns one event. If a plateform chooses to report
|
|
* multiple events through a single interrupt, it must ensure that the
|
|
* interrupt remains asserted until check-exception has been used to
|
|
* process all out-standing events for that interrupt.
|
|
*
|
|
* Implementation notes:
|
|
* - Events must be processed in the order they are returned. Hence,
|
|
* sequential in nature.
|
|
* - The owner of an event is determined by combinations of scope,
|
|
* event type, and sub-type. There is no easy way to pre-sort clients
|
|
* by scope or event type alone. For example, Torrent ISR route change
|
|
* event is reported with scope 0x00 (Not Applicable) rather than
|
|
* 0x3B (Torrent-hub). It is better to let the clients to identify
|
|
* who owns the event.
|
|
*/
|
|
|
|
static irqreturn_t ioei_interrupt(int irq, void *dev_id)
|
|
{
|
|
struct pseries_io_event *event;
|
|
int rtas_rc;
|
|
|
|
for (;;) {
|
|
rtas_rc = rtas_call(ioei_check_exception_token, 6, 1, NULL,
|
|
RTAS_VECTOR_EXTERNAL_INTERRUPT,
|
|
virq_to_hw(irq),
|
|
RTAS_IO_EVENTS, 1 /* Time Critical */,
|
|
__pa(ioei_rtas_buf),
|
|
RTAS_DATA_BUF_SIZE);
|
|
if (rtas_rc != 0)
|
|
break;
|
|
|
|
event = ioei_find_event((struct rtas_error_log *)ioei_rtas_buf);
|
|
if (!event)
|
|
continue;
|
|
|
|
atomic_notifier_call_chain(&pseries_ioei_notifier_list,
|
|
0, event);
|
|
}
|
|
return IRQ_HANDLED;
|
|
}
|
|
|
|
static int __init ioei_init(void)
|
|
{
|
|
struct device_node *np;
|
|
|
|
ioei_check_exception_token = rtas_token("check-exception");
|
|
if (ioei_check_exception_token == RTAS_UNKNOWN_SERVICE)
|
|
return -ENODEV;
|
|
|
|
np = of_find_node_by_path("/event-sources/ibm,io-events");
|
|
if (np) {
|
|
request_event_sources_irqs(np, ioei_interrupt, "IO_EVENT");
|
|
pr_info("IBM I/O event interrupts enabled\n");
|
|
of_node_put(np);
|
|
} else {
|
|
return -ENODEV;
|
|
}
|
|
return 0;
|
|
}
|
|
machine_subsys_initcall(pseries, ioei_init);
|
|
|