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authorMagnus Damm <damm@opensource.se>2013-09-14 15:29:07 (GMT)
committerSimon Horman <horms+renesas@verge.net.au>2013-09-30 08:56:11 (GMT)
commitee490bcc4f2d456c40df93236cf6a1bce2d5ddd0 (patch)
tree7dfca475fa3fe97061d64d2f9095b8d934278381
parente4550216ef8245b1c9892239a2121a7b15ac2e91 (diff)
downloadlinux-ee490bcc4f2d456c40df93236cf6a1bce2d5ddd0.tar.xz
ARM: shmobile: Extend APMU code to allow single cluster only
Extend the APMU code with a check to only allow boot of CPU cores that sit in the same cluster as CPU0. This makes it possible for people to use the r8a790 CA7 boot mode with CA7-cores only. The default CA15 boot mode will enable CA15 cores only. This is an intentional software limitation to cope with lacking scheduler support. By removing this patch it is possible to run all 8 cores in parallel, but this is not recommended without out of tree scheduler modfications or custom user space code to control the CPU affinitiy. Signed-off-by: Magnus Damm <damm@opensource.se> Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
-rw-r--r--arch/arm/mach-shmobile/platsmp-apmu.c13
1 files changed, 13 insertions, 0 deletions
diff --git a/arch/arm/mach-shmobile/platsmp-apmu.c b/arch/arm/mach-shmobile/platsmp-apmu.c
index 34dc40d..caaaa35 100644
--- a/arch/arm/mach-shmobile/platsmp-apmu.c
+++ b/arch/arm/mach-shmobile/platsmp-apmu.c
@@ -94,8 +94,21 @@ static void apmu_parse_cfg(void (*fn)(struct resource *res, int cpu, int bit))
u32 id;
int k;
int bit, index;
+ bool is_allowed;
for (k = 0; k < ARRAY_SIZE(apmu_config); k++) {
+ /* only enable the cluster that includes the boot CPU */
+ is_allowed = false;
+ for (bit = 0; bit < ARRAY_SIZE(apmu_config[k].cpus); bit++) {
+ id = apmu_config[k].cpus[bit];
+ if (id >= 0) {
+ if (id == cpu_logical_map(0))
+ is_allowed = true;
+ }
+ }
+ if (!is_allowed)
+ continue;
+
for (bit = 0; bit < ARRAY_SIZE(apmu_config[k].cpus); bit++) {
id = apmu_config[k].cpus[bit];
if (id >= 0) {