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ARM: l2c: avoid calling outer_flush_all() unnecessarily (Spear)

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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>
This commit is contained in:
Russell King 2014-03-15 16:47:47 +00:00
parent b13b9e98b8
commit 03a166e22a
1 changed files with 14 additions and 5 deletions
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19
arch/arm/mach-spear/platsmp.c
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@ -20,6 +20,18 @@
#include <mach/spear.h> #include <mach/spear.h>
#include "generic.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 DEFINE_SPINLOCK(boot_lock);
static void __iomem *scu_base = IOMEM(VA_SCU_BASE); 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 * let the primary processor know we're out of the
* pen, then head off into the C entry point * pen, then head off into the C entry point
*/ */
pen_release = -1; write_pen_release(-1);
smp_wmb();
/* /*
* Synchronise with the boot thread. * 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 * Note that "pen_release" is the hardware CPU ID, whereas
* "cpu" is Linux's internal ID. * "cpu" is Linux's internal ID.
*/ */
pen_release = cpu; write_pen_release(cpu);
flush_cache_all();
outer_flush_all();
timeout = jiffies + (1 * HZ); timeout = jiffies + (1 * HZ);
while (time_before(jiffies, timeout)) { while (time_before(jiffies, timeout)) {