From: "Clément Péron" <peron.clem@gmail.com>
To: Rob Herring <robh@kernel.org>,
Tomeu Vizoso <tomeu.vizoso@collabora.com>,
Steven Price <steven.price@arm.com>,
Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>,
Viresh Kumar <vireshk@kernel.org>, Nishanth Menon <nm@ti.com>,
Stephen Boyd <sboyd@kernel.org>,
Maxime Ripard <mripard@kernel.org>, Chen-Yu Tsai <wens@csie.org>
Cc: dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org,
"Clément Péron" <peron.clem@gmail.com>
Subject: [PATCH v2 05/14] drm/panfrost: use spinlock instead of atomic
Date: Sat, 4 Jul 2020 12:25:26 +0200 [thread overview]
Message-ID: <20200704102535.189647-6-peron.clem@gmail.com> (raw)
In-Reply-To: <20200704102535.189647-1-peron.clem@gmail.com>
Convert busy_count to a simple int protected by spinlock.
Signed-off-by: Clément Péron <peron.clem@gmail.com>
Reviewed-by: Steven Price <steven.price@arm.com>
---
drivers/gpu/drm/panfrost/panfrost_devfreq.c | 43 +++++++++++++++------
drivers/gpu/drm/panfrost/panfrost_devfreq.h | 9 ++++-
2 files changed, 40 insertions(+), 12 deletions(-)
diff --git a/drivers/gpu/drm/panfrost/panfrost_devfreq.c b/drivers/gpu/drm/panfrost/panfrost_devfreq.c
index 962550363391..78753cfb59fb 100644
--- a/drivers/gpu/drm/panfrost/panfrost_devfreq.c
+++ b/drivers/gpu/drm/panfrost/panfrost_devfreq.c
@@ -12,16 +12,12 @@
static void panfrost_devfreq_update_utilization(struct panfrost_devfreq *pfdevfreq)
{
- ktime_t now;
- ktime_t last;
-
- if (!pfdevfreq->devfreq)
- return;
+ ktime_t now, last;
now = ktime_get();
last = pfdevfreq->time_last_update;
- if (atomic_read(&pfdevfreq->busy_count) > 0)
+ if (pfdevfreq->busy_count > 0)
pfdevfreq->busy_time += ktime_sub(now, last);
else
pfdevfreq->idle_time += ktime_sub(now, last);
@@ -59,10 +55,14 @@ static int panfrost_devfreq_get_dev_status(struct device *dev,
{
struct panfrost_device *pfdev = dev_get_drvdata(dev);
struct panfrost_devfreq *pfdevfreq = &pfdev->pfdevfreq;
+ unsigned long irqflags;
+
+ status->current_frequency = clk_get_rate(pfdev->clock);
+
+ spin_lock_irqsave(&pfdevfreq->lock, irqflags);
panfrost_devfreq_update_utilization(pfdevfreq);
- status->current_frequency = clk_get_rate(pfdev->clock);
status->total_time = ktime_to_ns(ktime_add(pfdevfreq->busy_time,
pfdevfreq->idle_time));
@@ -70,6 +70,8 @@ static int panfrost_devfreq_get_dev_status(struct device *dev,
panfrost_devfreq_reset(pfdevfreq);
+ spin_unlock_irqrestore(&pfdevfreq->lock, irqflags);
+
dev_dbg(pfdev->dev, "busy %lu total %lu %lu %% freq %lu MHz\n",
status->busy_time, status->total_time,
status->busy_time / (status->total_time / 100),
@@ -100,6 +102,8 @@ int panfrost_devfreq_init(struct panfrost_device *pfdev)
else if (ret)
return ret;
+ spin_lock_init(&pfdevfreq->lock);
+
panfrost_devfreq_reset(pfdevfreq);
cur_freq = clk_get_rate(pfdev->clock);
@@ -162,15 +166,32 @@ void panfrost_devfreq_suspend(struct panfrost_device *pfdev)
void panfrost_devfreq_record_busy(struct panfrost_devfreq *pfdevfreq)
{
+ unsigned long irqflags;
+
+ if (!pfdevfreq->devfreq)
+ return;
+
+ spin_lock_irqsave(&pfdevfreq->lock, irqflags);
+
panfrost_devfreq_update_utilization(pfdevfreq);
- atomic_inc(&pfdevfreq->busy_count);
+
+ pfdevfreq->busy_count++;
+
+ spin_unlock_irqrestore(&pfdevfreq->lock, irqflags);
}
void panfrost_devfreq_record_idle(struct panfrost_devfreq *pfdevfreq)
{
- int count;
+ unsigned long irqflags;
+
+ if (!pfdevfreq->devfreq)
+ return;
+
+ spin_lock_irqsave(&pfdevfreq->lock, irqflags);
panfrost_devfreq_update_utilization(pfdevfreq);
- count = atomic_dec_if_positive(&pfdevfreq->busy_count);
- WARN_ON(count < 0);
+
+ WARN_ON(--pfdevfreq->busy_count < 0);
+
+ spin_unlock_irqrestore(&pfdevfreq->lock, irqflags);
}
diff --git a/drivers/gpu/drm/panfrost/panfrost_devfreq.h b/drivers/gpu/drm/panfrost/panfrost_devfreq.h
index 0697f8d5aa34..3392df1020be 100644
--- a/drivers/gpu/drm/panfrost/panfrost_devfreq.h
+++ b/drivers/gpu/drm/panfrost/panfrost_devfreq.h
@@ -4,6 +4,7 @@
#ifndef __PANFROST_DEVFREQ_H__
#define __PANFROST_DEVFREQ_H__
+#include <linux/spinlock.h>
#include <linux/ktime.h>
struct devfreq;
@@ -14,10 +15,16 @@ struct panfrost_device;
struct panfrost_devfreq {
struct devfreq *devfreq;
struct thermal_cooling_device *cooling;
+
ktime_t busy_time;
ktime_t idle_time;
ktime_t time_last_update;
- atomic_t busy_count;
+ int busy_count;
+ /*
+ * Protect busy_time, idle_time, time_last_update and busy_count
+ * because these can be updated concurrently between multiple jobs.
+ */
+ spinlock_t lock;
};
int panfrost_devfreq_init(struct panfrost_device *pfdev);
--
2.25.1
next prev parent reply other threads:[~2020-07-04 10:26 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-04 10:25 [PATCH v2 00/14] Add regulator devfreq support to Panfrost Clément Péron
2020-07-04 10:25 ` [PATCH v2 01/14] drm/panfrost: avoid static declaration Clément Péron
2020-07-04 10:25 ` [PATCH v2 02/14] drm/panfrost: clean headers in devfreq Clément Péron
2020-07-04 10:25 ` [PATCH v2 03/14] drm/panfrost: don't use pfdevfreq.busy_count to know if hw is idle Clément Péron
2020-07-04 10:25 ` [PATCH v2 04/14] drm/panfrost: introduce panfrost_devfreq struct Clément Péron
2020-07-04 10:25 ` Clément Péron [this message]
2020-07-04 10:25 ` [PATCH v2 06/14] drm/panfrost: properly handle error in probe Clément Péron
2020-07-04 10:25 ` [PATCH v2 07/14] drm/panfrost: rename error labels in device_init Clément Péron
2020-07-04 10:25 ` [PATCH v2 08/14] drm/panfrost: move devfreq_init()/fini() in device Clément Péron
2020-07-04 10:25 ` [PATCH v2 09/14] drm/panfrost: dynamically alloc regulators Clément Péron
2020-07-04 10:25 ` [PATCH v2 10/14] drm/panfrost: add regulators to devfreq Clément Péron
2020-07-04 10:25 ` [PATCH v2 11/14] arm64: defconfig: Enable devfreq cooling device Clément Péron
2020-07-04 10:25 ` [PATCH v2 12/14] arm64: dts: allwinner: h6: Add cooling map for GPU Clément Péron
2020-07-04 10:25 ` [PATCH v2 13/14] [DO NOT MERGE] arm64: dts: allwinner: h6: Add GPU OPP table Clément Péron
2020-07-04 12:13 ` Maxime Ripard
2020-07-04 14:56 ` Clément Péron
2020-08-03 7:54 ` Clément Péron
2020-08-24 13:11 ` Maxime Ripard
2020-08-28 12:16 ` Clément Péron
2020-08-28 12:21 ` Ondřej Jirman
2020-08-28 13:01 ` [linux-sunxi] " Jernej Škrabec
2020-07-04 10:25 ` [PATCH v2 14/14] [DO NOT MERGE] arm64: dts: allwinner: force GPU regulator to be always Clément Péron
2020-07-04 10:30 ` Clément Péron
2020-07-04 10:28 ` [PATCH v2 00/14] Add regulator devfreq support to Panfrost Clément Péron
2020-07-06 13:26 ` Alyssa Rosenzweig
2020-07-07 0:16 ` Ondřej Jirman
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