All of lore.kernel.org
 help / color / mirror / Atom feed
From: Russell King <rmk+kernel@armlinux.org.uk>
To: linux-arm-msm@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org,
	Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Subject: [PATCH 5/5] ARM: actions: remove boot_lock and pen_release
Date: Thu, 13 Dec 2018 11:55:57 +0000	[thread overview]
Message-ID: <E1gXPav-00064t-KY@rmk-PC.armlinux.org.uk> (raw)

The actions SMP implementation has several issues:

1. pen_release is only ever read and compared to -1, and is defined in
   arch/arm/kernel/smp.c to be -1.  This test will always succeed.

2. we are already guaranteed to be single threaded while bringing up a
   CPU, so the spinlock makes no sense, remove it.

3. owl_secondary_startup() is not referenced nor defined, the prototype
   is redundant, remove it.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
---
 arch/arm/mach-actions/platsmp.c | 15 ---------------
 1 file changed, 15 deletions(-)

diff --git a/arch/arm/mach-actions/platsmp.c b/arch/arm/mach-actions/platsmp.c
index 3efaa10efc43..4fd479c948e6 100644
--- a/arch/arm/mach-actions/platsmp.c
+++ b/arch/arm/mach-actions/platsmp.c
@@ -39,10 +39,6 @@ static void __iomem *sps_base_addr;
 static void __iomem *timer_base_addr;
 static int ncores;
 
-static DEFINE_SPINLOCK(boot_lock);
-
-void owl_secondary_startup(void);
-
 static int s500_wakeup_secondary(unsigned int cpu)
 {
 	int ret;
@@ -84,7 +80,6 @@ static int s500_wakeup_secondary(unsigned int cpu)
 
 static int s500_smp_boot_secondary(unsigned int cpu, struct task_struct *idle)
 {
-	unsigned long timeout;
 	int ret;
 
 	ret = s500_wakeup_secondary(cpu);
@@ -93,21 +88,11 @@ static int s500_smp_boot_secondary(unsigned int cpu, struct task_struct *idle)
 
 	udelay(10);
 
-	spin_lock(&boot_lock);
-
 	smp_send_reschedule(cpu);
 
-	timeout = jiffies + (1 * HZ);
-	while (time_before(jiffies, timeout)) {
-		if (pen_release == -1)
-			break;
-	}
-
 	writel(0, timer_base_addr + OWL_CPU1_ADDR + (cpu - 1) * 4);
 	writel(0, timer_base_addr + OWL_CPU1_FLAG + (cpu - 1) * 4);
 
-	spin_unlock(&boot_lock);
-
 	return 0;
 }
 
-- 
2.7.4

WARNING: multiple messages have this Message-ID (diff)
From: Russell King <rmk+kernel@armlinux.org.uk>
To: linux-arm-msm@vger.kernel.org
Cc: Andreas Färber <afaerber@suse.de>,
	linux-arm-kernel@lists.infradead.org,
	Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Subject: [PATCH 5/5] ARM: actions: remove boot_lock and pen_release
Date: Thu, 13 Dec 2018 11:55:57 +0000	[thread overview]
Message-ID: <E1gXPav-00064t-KY@rmk-PC.armlinux.org.uk> (raw)

The actions SMP implementation has several issues:

1. pen_release is only ever read and compared to -1, and is defined in
   arch/arm/kernel/smp.c to be -1.  This test will always succeed.

2. we are already guaranteed to be single threaded while bringing up a
   CPU, so the spinlock makes no sense, remove it.

3. owl_secondary_startup() is not referenced nor defined, the prototype
   is redundant, remove it.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
---
 arch/arm/mach-actions/platsmp.c | 15 ---------------
 1 file changed, 15 deletions(-)

diff --git a/arch/arm/mach-actions/platsmp.c b/arch/arm/mach-actions/platsmp.c
index 3efaa10efc43..4fd479c948e6 100644
--- a/arch/arm/mach-actions/platsmp.c
+++ b/arch/arm/mach-actions/platsmp.c
@@ -39,10 +39,6 @@ static void __iomem *sps_base_addr;
 static void __iomem *timer_base_addr;
 static int ncores;
 
-static DEFINE_SPINLOCK(boot_lock);
-
-void owl_secondary_startup(void);
-
 static int s500_wakeup_secondary(unsigned int cpu)
 {
 	int ret;
@@ -84,7 +80,6 @@ static int s500_wakeup_secondary(unsigned int cpu)
 
 static int s500_smp_boot_secondary(unsigned int cpu, struct task_struct *idle)
 {
-	unsigned long timeout;
 	int ret;
 
 	ret = s500_wakeup_secondary(cpu);
@@ -93,21 +88,11 @@ static int s500_smp_boot_secondary(unsigned int cpu, struct task_struct *idle)
 
 	udelay(10);
 
-	spin_lock(&boot_lock);
-
 	smp_send_reschedule(cpu);
 
-	timeout = jiffies + (1 * HZ);
-	while (time_before(jiffies, timeout)) {
-		if (pen_release == -1)
-			break;
-	}
-
 	writel(0, timer_base_addr + OWL_CPU1_ADDR + (cpu - 1) * 4);
 	writel(0, timer_base_addr + OWL_CPU1_FLAG + (cpu - 1) * 4);
 
-	spin_unlock(&boot_lock);
-
 	return 0;
 }
 
-- 
2.7.4


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

             reply	other threads:[~2018-12-13 11:55 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-12-13 11:55 Russell King [this message]
2018-12-13 11:55 ` [PATCH 5/5] ARM: actions: remove boot_lock and pen_release Russell King
2018-12-13 12:01 ` Manivannan Sadhasivam
2018-12-13 12:01   ` Manivannan Sadhasivam
2018-12-13 12:04   ` Russell King - ARM Linux
2018-12-13 12:04     ` Russell King - ARM Linux
2019-01-11  8:19   ` Linus Walleij
2019-01-11  8:19     ` Linus Walleij

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=E1gXPav-00064t-KY@rmk-PC.armlinux.org.uk \
    --to=rmk+kernel@armlinux.org.uk \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-arm-msm@vger.kernel.org \
    --cc=manivannan.sadhasivam@linaro.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.