linux/arch/arm/mach-highbank/hotplug.c
Rob Herring 73053d973d ARM: highbank: fix cache flush ordering for cpu hotplug
The L1 data cache flush needs to be after highbank_set_cpu_jump call which
pollutes the cache with the l2x0_lock. This causes other cores to deadlock
waiting for the l2x0_lock. Moving the flush of the entire data cache after
highbank_set_cpu_jump fixes the problem. Use flush_cache_louis instead of
flush_cache_all are that is sufficient to flush only the L1 data cache.
flush_cache_louis did not exist when highbank_cpu_die was originally
written.

With PL310 errata 769419 enabled, a wmb is inserted into idle which takes
the l2x0_lock. This makes the problem much more easily hit and causes
reset to hang.

Reported-by: Paolo Pisati <p.pisati@gmail.com>
Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Signed-off-by: Olof Johansson <olof@lixom.net>
2013-04-18 09:37:46 -07:00

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C

/*
* Copyright 2011 Calxeda, Inc.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <linux/kernel.h>
#include <asm/cacheflush.h>
#include "core.h"
#include "sysregs.h"
extern void secondary_startup(void);
/*
* platform-specific code to shutdown a CPU
*
*/
void __ref highbank_cpu_die(unsigned int cpu)
{
highbank_set_cpu_jump(cpu, phys_to_virt(0));
flush_cache_louis();
highbank_set_core_pwr();
while (1)
cpu_do_idle();
}