Commit e21fee53 authored by Peter Zijlstra (Intel)'s avatar Peter Zijlstra (Intel) Committed by Peter Zijlstra
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powerpc/ps3: Convert half completion to rcuwait 



The PS3 notification interrupt and kthread use a hacked up completion to
communicate. Since we're wanting to change the completion implementation and
this is abuse anyway, replace it with a simple rcuwait since there is only ever
the one waiter.

AFAICT the kthread uses TASK_INTERRUPTIBLE to not increase loadavg, kthreads
cannot receive signals by default and this one doesn't look different. Use
TASK_IDLE instead.

Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200321113241.930037873@linutronix.de
parent 80fbaf1c

arch/powerpc/platforms/ps3/device-init.c

+9 −9
Original line number Diff line number Diff line
@@ -13,6 +13,7 @@ 
#include <linux/init.h>

#include <linux/slab.h>

#include <linux/reboot.h>

#include <linux/rcuwait.h>



#include <asm/firmware.h>

#include <asm/lv1call.h>
@@ -670,7 +671,8 @@ struct ps3_notification_device { 
	spinlock_t lock;

	u64 tag;

	u64 lv1_status;

	struct completion done;

	struct rcuwait wait;

	bool done;

};



enum ps3_notify_type {
@@ -712,7 +714,8 @@ static irqreturn_t ps3_notification_interrupt(int irq, void *data) 
		pr_debug("%s:%u: completed, status 0x%llx\n", __func__,

			 __LINE__, status);

		dev->lv1_status = status;

		complete(&dev->done);

		dev->done = true;

		rcuwait_wake_up(&dev->wait);

	}

	spin_unlock(&dev->lock);

	return IRQ_HANDLED;
@@ -725,12 +728,12 @@ static int ps3_notification_read_write(struct ps3_notification_device *dev, 
	unsigned long flags;

	int res;



	init_completion(&dev->done);

	spin_lock_irqsave(&dev->lock, flags);

	res = write ? lv1_storage_write(dev->sbd.dev_id, 0, 0, 1, 0, lpar,

					&dev->tag)

		    : lv1_storage_read(dev->sbd.dev_id, 0, 0, 1, 0, lpar,

				       &dev->tag);

	dev->done = false;

	spin_unlock_irqrestore(&dev->lock, flags);

	if (res) {

		pr_err("%s:%u: %s failed %d\n", __func__, __LINE__, op, res);
@@ -738,14 +741,10 @@ static int ps3_notification_read_write(struct ps3_notification_device *dev, 
	}

	pr_debug("%s:%u: notification %s issued\n", __func__, __LINE__, op);



	res = wait_event_interruptible(dev->done.wait,

				       dev->done.done || kthread_should_stop());

	rcuwait_wait_event(&dev->wait, dev->done || kthread_should_stop(), TASK_IDLE);



	if (kthread_should_stop())

		res = -EINTR;

	if (res) {

		pr_debug("%s:%u: interrupted %s\n", __func__, __LINE__, op);

		return res;

	}



	if (dev->lv1_status) {

		pr_err("%s:%u: %s not completed, status 0x%llx\n", __func__,
@@ -810,6 +809,7 @@ static int ps3_probe_thread(void *data) 
	}



	spin_lock_init(&dev.lock);

	rcuwait_init(&dev.wait);



	res = request_irq(irq, ps3_notification_interrupt, 0,

			  "ps3_notification", &dev);

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