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Commit 0e0ba769 authored by Catalin Marinas's avatar Catalin Marinas Committed by Russell King
Browse files

[ARM] 4201/1: SMP barriers pair needed for the secondary boot process 



In some situations, the pen_release store in platform_secondary_init()
may stay forever in the write buffer while the CPU is waiting on the
boot_lock to be released in boot_secondary(). The primary CPU could
never see the pen_release update without the barriers.

Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent 7770bddb

arch/arm/mach-realview/platsmp.c

+2 −0
Original line number Original line Diff line number Diff line
@@ -59,6 +59,7 @@ void __cpuinit platform_secondary_init(unsigned int cpu) 
	 * pen, then head off into the C entry point

	 * pen, then head off into the C entry point

	 */

	 */

	pen_release = -1;

	pen_release = -1;

	smp_wmb();





	/*

	/*

	 * Synchronise with the boot thread.

	 * Synchronise with the boot thread.
@@ -102,6 +103,7 @@ int __cpuinit boot_secondary(unsigned int cpu, struct task_struct *idle) 




	timeout = jiffies + (1 * HZ);

	timeout = jiffies + (1 * HZ);

	while (time_before(jiffies, timeout)) {

	while (time_before(jiffies, timeout)) {

		smp_rmb();

		if (pen_release == -1)

		if (pen_release == -1)

			break;

			break;