armv7r: K3: Allow SPL to run only on core 0

Based on the MCU R5 efuse settings, R5F cores in MCU domain
either work in split mode or in lock step mode.

If efuse settings are in lockstep mode: ROM release R5 cores
and SPL continues to run on the R5 core is lockstep mode.

If efuse settings are in split mode: ROM releases both the R5
cores simultaneously and allow SPL to run on both the cores.
In this case it is bootloader's responsibility to detect core
1 and park it. Else both the core will be running bootloader
independently which might result in an unexpected behaviour.

Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Reviewed-by: Tom Rini <trini@konsulko.com>

diff --git a/arch/arm/mach-k3/Makefile b/arch/arm/mach-k3/Makefile
index 406dda3..bd4ab36 100644 (file)
--- a/arch/arm/mach-k3/Makefile
+++ b/arch/arm/mach-k3/Makefile
@@ -5,5 +5,5 @@
 
 obj-$(CONFIG_SOC_K3_AM6) += am6_init.o
 obj-$(CONFIG_ARM64) += arm64-mmu.o
-obj-$(CONFIG_CPU_V7R) += r5_mpu.o
+obj-$(CONFIG_CPU_V7R) += r5_mpu.o lowlevel_init.o
 obj-y += common.o

diff --git a/arch/arm/mach-k3/lowlevel_init.S b/arch/arm/mach-k3/lowlevel_init.S
new file mode 100644 (file)
index 0000000..70c5d1c
--- /dev/null
+++ b/arch/arm/mach-k3/lowlevel_init.S
@@ -0,0 +1,20 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright (C) 2018 Texas Instruments Incorporated - http://www.ti.com/
+ *     Lokesh Vutla <lokeshvutla@ti.com>
+ */
+
+#include <linux/linkage.h>
+
+ENTRY(lowlevel_init)
+
+       mrc     p15, 0, r0, c0, c0, 5           @ Read MPIDR
+       and     r0, #0xff
+       cmp     r0, #0x0
+       bne     park_cpu
+       bx      lr
+park_cpu:
+       wfi
+       b       park_cpu
+
+ENDPROC(lowlevel_init)

diff --git a/include/configs/am65x_evm.h b/include/configs/am65x_evm.h
index 484c5ef..31749c6 100644 (file)
--- a/include/configs/am65x_evm.h
+++ b/include/configs/am65x_evm.h
@@ -29,7 +29,9 @@
 #define CONFIG_SPL_FS_LOAD_PAYLOAD_NAME        "tispl.bin"
 #endif
 
+#ifndef CONFIG_CPU_V7R
 #define CONFIG_SKIP_LOWLEVEL_INIT
+#endif
 
 #define CONFIG_SPL_MAX_SIZE            CONFIG_SYS_K3_MAX_DOWNLODABLE_IMAGE_SIZE
 #define CONFIG_SYS_INIT_SP_ADDR         (CONFIG_SPL_TEXT_BASE +        \