Commit 57574bd7 authored by Bhaktipriya Shridhar's avatar Bhaktipriya Shridhar Committed by Thierry Reding
Browse files

gpu: host1x: hw: intr_hw: Remove create_workqueue 



System workqueues have been able to handle high level of concurrency
for a long time now and there's no reason to use dedicated workqueues
just to gain concurrency. Since the workqueue host->intr_wq is involved
in sync point interrupts, and sync point wait and is not being used on
a memory reclaim path, dedicated host->intr_wq has been replaced with the
use of system_wq.

Unlike a dedicated per-cpu workqueue created with create_workqueue(),
system_wq allows multiple work items to overlap executions even on
the same CPU; however, a per-cpu workqueue doesn't have any CPU
locality or global ordering guarantees unless the target CPU is
explicitly specified and thus the increase of local concurrency
shouldn't make any difference.

cancel_work_sync() has been used  in _host1x_free_syncpt_irq() to ensure
that no work is pending by the time exit path runs.

Signed-off-by: default avatarBhaktipriya Shridhar <bhaktipriya96@gmail.com>
Acked-by: default avatarTejun Heo <tj@kernel.org>
Signed-off-by: default avatarThierry Reding <treding@nvidia.com>
parent dfa7573e

drivers/gpu/host1x/dev.h

+0 −1
Original line number Diff line number Diff line
@@ -109,7 +109,6 @@ struct host1x { 
	struct clk *clk;



	struct mutex intr_mutex;

	struct workqueue_struct *intr_wq;

	int intr_syncpt_irq;



	const struct host1x_syncpt_ops *syncpt_op;

drivers/gpu/host1x/hw/intr_hw.c

+6 −2
Original line number Diff line number Diff line
@@ -38,7 +38,7 @@ static void host1x_intr_syncpt_handle(struct host1x_syncpt *syncpt) 
	host1x_sync_writel(host, BIT_MASK(id),

		HOST1X_SYNC_SYNCPT_THRESH_CPU0_INT_STATUS(BIT_WORD(id)));



	queue_work(host->intr_wq, &syncpt->intr.work);

	schedule_work(&syncpt->intr.work);

}



static irqreturn_t syncpt_thresh_isr(int irq, void *dev_id)
@@ -127,8 +127,12 @@ static void _host1x_intr_disable_syncpt_intr(struct host1x *host, u32 id) 


static int _host1x_free_syncpt_irq(struct host1x *host)

{

	int i;



	devm_free_irq(host->dev, host->intr_syncpt_irq, host);

	flush_workqueue(host->intr_wq);



	for (i = 0; i < host->info->nb_pts; i++)

		cancel_work_sync(&host->syncpt[i].intr.work);

	return 0;

}

drivers/gpu/host1x/intr.c

+0 −4
Original line number Diff line number Diff line
@@ -277,9 +277,6 @@ int host1x_intr_init(struct host1x *host, unsigned int irq_sync) 


	mutex_init(&host->intr_mutex);

	host->intr_syncpt_irq = irq_sync;

	host->intr_wq = create_workqueue("host_syncpt");

	if (!host->intr_wq)

		return -ENOMEM;



	for (id = 0; id < nb_pts; ++id) {

		struct host1x_syncpt *syncpt = host->syncpt + id;
@@ -299,7 +296,6 @@ int host1x_intr_init(struct host1x *host, unsigned int irq_sync) 
void host1x_intr_deinit(struct host1x *host)

{

	host1x_intr_stop(host);

	destroy_workqueue(host->intr_wq);

}



void host1x_intr_start(struct host1x *host)

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