[PATCH 1/2] ARM: zynq: support smp in thumb mode

From: Luis Araneda
Date: Mon Aug 05 2019 - 23:08:14 EST


Add .arm directive to headsmp.S to ensure that the
CPU starts in 32-bit ARM mode and the correct code
size is copied on smp bring-up

Additionally, start secondary CPUs on secondary_startup_arm
to automatically switch from ARM to thumb on a thumb kernel

Suggested-by: Michal Simek <michal.simek@xxxxxxxxxx>
Signed-off-by: Luis Araneda <luaraneda@xxxxxxxxx>
---
arch/arm/mach-zynq/headsmp.S | 2 ++
arch/arm/mach-zynq/platsmp.c | 2 +-
2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/arm/mach-zynq/headsmp.S b/arch/arm/mach-zynq/headsmp.S
index ab85003cf9ad..3449e0d1f990 100644
--- a/arch/arm/mach-zynq/headsmp.S
+++ b/arch/arm/mach-zynq/headsmp.S
@@ -7,6 +7,8 @@
#include <linux/init.h>
#include <asm/assembler.h>

+ .arm
+
ENTRY(zynq_secondary_trampoline)
ARM_BE8(setend be) @ ensure we are in BE8 mode
ldr r0, zynq_secondary_trampoline_jump
diff --git a/arch/arm/mach-zynq/platsmp.c b/arch/arm/mach-zynq/platsmp.c
index a7cfe07156f4..38728badabd4 100644
--- a/arch/arm/mach-zynq/platsmp.c
+++ b/arch/arm/mach-zynq/platsmp.c
@@ -81,7 +81,7 @@ EXPORT_SYMBOL(zynq_cpun_start);

static int zynq_boot_secondary(unsigned int cpu, struct task_struct *idle)
{
- return zynq_cpun_start(__pa_symbol(secondary_startup), cpu);
+ return zynq_cpun_start(__pa_symbol(secondary_startup_arm), cpu);
}

/*
--
2.22.0