From: Fabien Dessenne <fabien.dessenne@st.com>
Date: Thu, 7 Mar 2019 15:42:16 +0000 (+0100)
Subject: hwspinlock: stm32: implement the relax() ops
X-Git-Tag: v5.3-rc1~54^2~2
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=5cd69f13deef804d113d31c5c744396b1a1b8a9a;p=thirdparty%2Flinux.git

hwspinlock: stm32: implement the relax() ops

Implement this optional ops, called by hwspinlock core while spinning on
a lock, between two successive invocations of trylock().

Reviewed-by: Benjamin Gaignard <benjamin.gaignard@st.com>
Signed-off-by: Fabien Dessenne <fabien.dessenne@st.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
---

diff --git a/drivers/hwspinlock/stm32_hwspinlock.c b/drivers/hwspinlock/stm32_hwspinlock.c
index 4418392888935..c8eacf4f9692b 100644
--- a/drivers/hwspinlock/stm32_hwspinlock.c
+++ b/drivers/hwspinlock/stm32_hwspinlock.c
@@ -5,6 +5,7 @@
  */
 
 #include <linux/clk.h>
+#include <linux/delay.h>
 #include <linux/hwspinlock.h>
 #include <linux/io.h>
 #include <linux/kernel.h>
@@ -42,9 +43,15 @@ static void stm32_hwspinlock_unlock(struct hwspinlock *lock)
 	writel(STM32_MUTEX_COREID, lock_addr);
 }
 
+static void stm32_hwspinlock_relax(struct hwspinlock *lock)
+{
+	ndelay(50);
+}
+
 static const struct hwspinlock_ops stm32_hwspinlock_ops = {
 	.trylock	= stm32_hwspinlock_trylock,
 	.unlock		= stm32_hwspinlock_unlock,
+	.relax		= stm32_hwspinlock_relax,
 };
 
 static int stm32_hwspinlock_probe(struct platform_device *pdev)