arm64: add devicetree based CPU startup

This adds SMP bring up support for arm64 cpus. It's
reliant on DEVICE_PATH_CPU devices in the devicetree.
Then for each enabled device it attempts to start then
initialize each CPU.  Additionally, there is a cpu_action
construct which allows for running actions on an individual
cpu.

BUG=chrome-os-partner:31761
BRANCH=None
TEST=Booted both cores on ryu into linux.

Change-Id: I3e42fb668034c27808d706427a26be1558ad2af1
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Original-Commit-Id: a733fd566a8e5793da5ff28f9c16c213f411372e
Original-Change-Id: I407eabd0b6985fc4e86de57a9e034548ec8f3d81
Original-Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Original-Reviewed-on: https://chromium-review.googlesource.com/216925
Original-Reviewed-by: Furquan Shaikh <furquan@chromium.org>
Reviewed-on: http://review.coreboot.org/9042
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>

1 files changed, 12 insertions, 6 deletions

diff --git a/src/arch/arm64/c_entry.c b/src/arch/arm64/c_entry.c
index e2aa4e5fb3..aba9fd3719 100644
--- a/src/arch/arm64/c_entry.c
+++ b/src/arch/arm64/c_entry.c
@@ -70,12 +70,18 @@ static void secondary_cpu_start(void)
 {
 	mmu_enable();
 	exception_hwinit();
-	soc_secondary_cpu_init();
-	/*
-	 * TODO(adurbin): need a proper place to park the CPUs. Currently
-	 * assuming SoC code does the appropriate thing.
-	 */
-	while (1);
+
+	if (!IS_ENABLED(CONFIG_SMP)) {
+		soc_secondary_cpu_init();
+		/*
+		 * TODO(adurbin): need a proper place to park the CPUs.
+		 * Currently assuming SoC code does the appropriate thing.
+		 */
+		while (1);
+	}
+
+	/* This will never return. */
+	arch_secondary_cpu_init();
 }
 
 extern void arm64_cpu_startup(void);