[PATCH 3.14 46/59] powerpc: Dont skip ePAPR spin-table CPUs

From: Greg Kroah-Hartman
Date: Fri Jul 04 2014 - 18:35:07 EST


3.14-stable review patch. If anyone has any objections, please let me know.

------------------

From: Scott Wood <scottwood@xxxxxxxxxxxxx>

commit 6663a4fa6711050036562ddfd2086edf735fae21 upstream.

Commit 59a53afe70fd530040bdc69581f03d880157f15a "powerpc: Don't setup
CPUs with bad status" broke ePAPR SMP booting. ePAPR says that CPUs
that aren't presently running shall have status of disabled, with
enable-method being used to determine whether the CPU can be enabled.

Fix by checking for spin-table, which is currently the only supported
enable-method.

Signed-off-by: Scott Wood <scottwood@xxxxxxxxxxxxx>
Cc: Michael Neuling <mikey@xxxxxxxxxxx>
Cc: Emil Medve <Emilian.Medve@xxxxxxxxxxxxx>
Signed-off-by: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
arch/powerpc/kernel/setup-common.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)

--- a/arch/powerpc/kernel/setup-common.c
+++ b/arch/powerpc/kernel/setup-common.c
@@ -456,9 +456,17 @@ void __init smp_setup_cpu_maps(void)
}

for (j = 0; j < nthreads && cpu < nr_cpu_ids; j++) {
+ bool avail;
+
DBG(" thread %d -> cpu %d (hard id %d)\n",
j, cpu, be32_to_cpu(intserv[j]));
- set_cpu_present(cpu, of_device_is_available(dn));
+
+ avail = of_device_is_available(dn);
+ if (!avail)
+ avail = !of_property_match_string(dn,
+ "enable-method", "spin-table");
+
+ set_cpu_present(cpu, avail);
set_hard_smp_processor_id(cpu, be32_to_cpu(intserv[j]));
set_cpu_possible(cpu, true);
cpu++;


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