[PATCH 3.12 048/170] powerpc: Don't skip ePAPR spin-table CPUs

Jiri Slaby
2014-07-18T13:47:26Z

From: Scott Wood <scottwood@freescale.com>

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

===============

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@freescale.com>
Cc: Michael Neuling <mikey@neuling.org>
Cc: Emil Medve <Emilian.Medve@Freescale.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
arch/powerpc/kernel/setup-common.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/kernel/setup-common.c b/arch/powerpc/kernel/setup-common.c
index 0623cf3f8a61..5b86d6a47a1a 100644
--- a/arch/powerpc/kernel/setup-common.c
+++ b/arch/powerpc/kernel/setup-common.c
@@ -458,9 +458,17 @@ 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++;
--
2.0.0