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ARM: highbank: fix cache flush ordering for cpu hotplug

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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>
This commit is contained in:
Rob Herring 2013-04-17 10:46:52 -05:00 • committed by Olof Johansson
commit 73053d973d
1 changed files with 4 additions and 6 deletions
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10
arch/arm/mach-highbank/hotplug.c
View file

@ -28,13 +28,11 @@ extern void secondary_startup(void);
*/ */
void __ref highbank_cpu_die(unsigned int cpu) void __ref highbank_cpu_die(unsigned int cpu)
{ {
flush_cache_all();
highbank_set_cpu_jump(cpu, phys_to_virt(0)); highbank_set_cpu_jump(cpu, phys_to_virt(0));
flush_cache_louis();
highbank_set_core_pwr(); highbank_set_core_pwr();
cpu_do_idle(); while (1)
cpu_do_idle();
/* We should never return from idle */
panic("highbank: cpu %d unexpectedly exit from shutdown\n", cpu);
} }