Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 1bc98de2 authored by Gavin Shan's avatar Gavin Shan Committed by Benjamin Herrenschmidt
Browse files

powernv/opal: Notifier for OPAL events 



This patch implements a notifier to receive a notification on OPAL
event mask changes. The notifier is only called as a result of an OPAL
interrupt, which will happen upon reception of FSP messages or PCI errors.
Any event mask change detected as a result of opal_poll_events() will not
result in a notifier call.

[benh: changelog]
Signed-off-by: default avatarGavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
parent b95cd2cd

arch/powerpc/include/asm/opal.h

+5 −0
Original line number Diff line number Diff line
@@ -644,6 +644,11 @@ extern void hvc_opal_init_early(void); 
extern int early_init_dt_scan_opal(unsigned long node, const char *uname,

				   int depth, void *data);



extern int opal_notifier_register(struct notifier_block *nb);

extern void opal_notifier_enable(void);

extern void opal_notifier_disable(void);

extern void opal_notifier_update_evt(uint64_t evt_mask, uint64_t evt_val);



extern int opal_get_chars(uint32_t vtermno, char *buf, int count);

extern int opal_put_chars(uint32_t vtermno, const char *buf, int total_len);

arch/powerpc/platforms/powernv/opal.c

+68 −1
Original line number Diff line number Diff line
@@ -15,6 +15,7 @@ 
#include <linux/of.h>

#include <linux/of_platform.h>

#include <linux/interrupt.h>

#include <linux/notifier.h>

#include <linux/slab.h>

#include <asm/opal.h>

#include <asm/firmware.h>
@@ -31,6 +32,10 @@ static DEFINE_SPINLOCK(opal_write_lock); 
extern u64 opal_mc_secondary_handler[];

static unsigned int *opal_irqs;

static unsigned int opal_irq_count;

static ATOMIC_NOTIFIER_HEAD(opal_notifier_head);

static DEFINE_SPINLOCK(opal_notifier_lock);

static uint64_t last_notified_mask = 0x0ul;

static atomic_t opal_notifier_hold = ATOMIC_INIT(0);



int __init early_init_dt_scan_opal(unsigned long node,

				   const char *uname, int depth, void *data)
@@ -95,6 +100,68 @@ static int __init opal_register_exception_handlers(void) 


early_initcall(opal_register_exception_handlers);



int opal_notifier_register(struct notifier_block *nb)

{

	if (!nb) {

		pr_warning("%s: Invalid argument (%p)\n",

			   __func__, nb);

		return -EINVAL;

	}



	atomic_notifier_chain_register(&opal_notifier_head, nb);

	return 0;

}



static void opal_do_notifier(uint64_t events)

{

	unsigned long flags;

	uint64_t changed_mask;



	if (atomic_read(&opal_notifier_hold))

		return;



	spin_lock_irqsave(&opal_notifier_lock, flags);

	changed_mask = last_notified_mask ^ events;

	last_notified_mask = events;

	spin_unlock_irqrestore(&opal_notifier_lock, flags);



	/*

	 * We feed with the event bits and changed bits for

	 * enough information to the callback.

	 */

	atomic_notifier_call_chain(&opal_notifier_head,

				   events, (void *)changed_mask);

}



void opal_notifier_update_evt(uint64_t evt_mask,

			      uint64_t evt_val)

{

	unsigned long flags;



	spin_lock_irqsave(&opal_notifier_lock, flags);

	last_notified_mask &= ~evt_mask;

	last_notified_mask |= evt_val;

	spin_unlock_irqrestore(&opal_notifier_lock, flags);

}



void opal_notifier_enable(void)

{

	int64_t rc;

	uint64_t evt = 0;



	atomic_set(&opal_notifier_hold, 0);



	/* Process pending events */

	rc = opal_poll_events(&evt);

	if (rc == OPAL_SUCCESS && evt)

		opal_do_notifier(evt);

}



void opal_notifier_disable(void)

{

	atomic_set(&opal_notifier_hold, 1);

}



int opal_get_chars(uint32_t vtermno, char *buf, int count)

{

	s64 len, rc;
@@ -297,7 +364,7 @@ static irqreturn_t opal_interrupt(int irq, void *data) 


	opal_handle_interrupt(virq_to_hw(irq), &events);



	/* XXX TODO: Do something with the events */

	opal_do_notifier(events);



	return IRQ_HANDLED;

}