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authorRussell King <rmk+kernel@arm.linux.org.uk>2014-03-15 16:47:47 +0000
committerRussell King <rmk+kernel@arm.linux.org.uk>2014-05-22 16:38:38 +0100
commit03a166e22a49350010fc398a8cb9be3e93192fef (patch)
tree1e2a1286e8b1505530a636c09395ff52b1fe1cce /arch/arm/mach-spear/platsmp.c
parentb13b9e98b80fa24460a011ba0378d3fe56137a31 (diff)
downloadlinux-stericsson-03a166e22a49350010fc398a8cb9be3e93192fef.tar.gz
ARM: l2c: avoid calling outer_flush_all() unnecessarily (Spear)
Spear calls outer_flush_all() from it's SMP bringup function. This is potentially dangerous as the L2C set/way operations which implement this don't take kindly to concurrent operations. Besides, there's better solutions to this, as implemented on other platforms. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/mach-spear/platsmp.c')
-rw-r--r--arch/arm/mach-spear/platsmp.c19
1 files changed, 14 insertions, 5 deletions
diff --git a/arch/arm/mach-spear/platsmp.c b/arch/arm/mach-spear/platsmp.c
index c19751fff2c6..fd4297713d67 100644
--- a/arch/arm/mach-spear/platsmp.c
+++ b/arch/arm/mach-spear/platsmp.c
@@ -20,6 +20,18 @@
#include <mach/spear.h>
#include "generic.h"
+/*
+ * Write pen_release in a way that is guaranteed to be visible to all
+ * observers, irrespective of whether they're taking part in coherency
+ * or not. This is necessary for the hotplug code to work reliably.
+ */
+static void write_pen_release(int val)
+{
+ pen_release = val;
+ smp_wmb();
+ sync_cache_w(&pen_release);
+}
+
static DEFINE_SPINLOCK(boot_lock);
static void __iomem *scu_base = IOMEM(VA_SCU_BASE);
@@ -30,8 +42,7 @@ static void spear13xx_secondary_init(unsigned int cpu)
* let the primary processor know we're out of the
* pen, then head off into the C entry point
*/
- pen_release = -1;
- smp_wmb();
+ write_pen_release(-1);
/*
* Synchronise with the boot thread.
@@ -58,9 +69,7 @@ static int spear13xx_boot_secondary(unsigned int cpu, struct task_struct *idle)
* Note that "pen_release" is the hardware CPU ID, whereas
* "cpu" is Linux's internal ID.
*/
- pen_release = cpu;
- flush_cache_all();
- outer_flush_all();
+ write_pen_release(cpu);
timeout = jiffies + (1 * HZ);
while (time_before(jiffies, timeout)) {