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| author | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2011-02-10 18:45:24 +1100 |
|---|---|---|
| committer | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2011-04-01 15:37:09 +1100 |
| commit | fa3f82c8bb7acbe049ea71f258b3ae0a33d9d40b (patch) | |
| tree | 9c5e71195c7948c139ea37d8d0e0287f062910f9 /arch/powerpc/kernel/smp.c | |
| parent | 963e5d3b76d657f1ebcf3561446d2ba1872bbfa2 (diff) | |
| download | kernel_samsung_smdk4412-fa3f82c8bb7acbe049ea71f258b3ae0a33d9d40b.zip kernel_samsung_smdk4412-fa3f82c8bb7acbe049ea71f258b3ae0a33d9d40b.tar.gz kernel_samsung_smdk4412-fa3f82c8bb7acbe049ea71f258b3ae0a33d9d40b.tar.bz2 | |
powerpc/smp: soft-replugged CPUs must go back to start_secondary
Various thing are torn down when a CPU is hot-unplugged. That CPU
is expected to go back to start_secondary when re-plugged to re
initialize everything, such as clock sources, maps, ...
Some implementations just return from cpu_die() callback
in the idle loop when the CPU is "re-plugged". This is not enough.
We fix it using a little asm trampoline which resets the stack
and calls back into start_secondary as if we were all fresh from
boot. The trampoline already existed on ppc64, but we add it for
ppc32
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc/kernel/smp.c')
| -rw-r--r-- | arch/powerpc/kernel/smp.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c index 9813605..1c9956c 100644 --- a/arch/powerpc/kernel/smp.c +++ b/arch/powerpc/kernel/smp.c @@ -502,7 +502,7 @@ static struct device_node *cpu_to_l2cache(int cpu) } /* Activate a secondary processor. */ -int __devinit start_secondary(void *unused) +void __devinit start_secondary(void *unused) { unsigned int cpu = smp_processor_id(); struct device_node *l2_cache; @@ -558,7 +558,8 @@ int __devinit start_secondary(void *unused) local_irq_enable(); cpu_idle(); - return 0; + + BUG(); } int setup_profiling_timer(unsigned int multiplier) @@ -660,5 +661,9 @@ void cpu_die(void) { if (ppc_md.cpu_die) ppc_md.cpu_die(); + + /* If we return, we re-enter start_secondary */ + start_secondary_resume(); } + #endif |