[PATCH v1 05/16] arm: socfpga: soc64: Override 'lowlevel_init' to support ATF

[Chee Hong Ang]

Override 'lowlevel_init' to make sure secondary CPUs trapped
in ATF instead of SPL. After ATF is initialized, it will signal
the secondary CPUs to jump from SPL to ATF waiting to be 'activated'
by Linux OS via PSCI call.

Signed-off-by: Chee Hong Ang <chee.hong.ang at intel.com>
---
 arch/arm/mach-socfpga/Makefile              |  2 +
 arch/arm/mach-socfpga/lowlevel_init_soc64.S | 76 +++++++++++++++++++++
 2 files changed, 78 insertions(+)
 create mode 100644 arch/arm/mach-socfpga/lowlevel_init_soc64.S

diff --git a/arch/arm/mach-socfpga/Makefile b/arch/arm/mach-socfpga/Makefile
index 418f543b20..c63162a5c6 100644
--- a/arch/arm/mach-socfpga/Makefile
+++ b/arch/arm/mach-socfpga/Makefile
@@ -29,6 +29,7 @@ endif
 
 ifdef CONFIG_TARGET_SOCFPGA_STRATIX10
 obj-y	+= clock_manager_s10.o
+obj-y	+= lowlevel_init_soc64.o
 obj-y	+= mailbox_s10.o
 obj-y	+= misc_s10.o
 obj-y	+= mmu-arm64_s10.o
@@ -41,6 +42,7 @@ endif
 
 ifdef CONFIG_TARGET_SOCFPGA_AGILEX
 obj-y	+= clock_manager_agilex.o
+obj-y	+= lowlevel_init_soc64.o
 obj-y	+= mailbox_s10.o
 obj-y	+= misc_s10.o
 obj-y	+= mmu-arm64_s10.o
diff --git a/arch/arm/mach-socfpga/lowlevel_init_soc64.S b/arch/arm/mach-socfpga/lowlevel_init_soc64.S
new file mode 100644
index 0000000000..612ea8a037
--- /dev/null
+++ b/arch/arm/mach-socfpga/lowlevel_init_soc64.S
@@ -0,0 +1,76 @@
+/*
+ * Copyright (C) 2020 Intel Corporation. All rights reserved
+ *
+ * SPDX-License-Identifier:    GPL-2.0
+ */
+
+#include <asm-offsets.h>
+#include <config.h>
+#include <linux/linkage.h>
+#include <asm/macro.h>
+
+ENTRY(lowlevel_init)
+	mov	x29, lr			/* Save LR */
+
+#if defined(CONFIG_GICV2) || defined(CONFIG_GICV3)
+#if defined(CONFIG_SPL_BUILD) && defined(CONFIG_SPL_ATF)
+wait_for_atf:
+	ldr	x4, =CPU_RELEASE_ADDR
+	ldr	x5, [x4]
+	cbz	x5, slave_wait_atf
+	br	x5
+slave_wait_atf:
+	branch_if_slave x0, wait_for_atf
+#else
+	branch_if_slave x0, 1f
+#endif
+	ldr	x0, =GICD_BASE
+	bl	gic_init_secure
+1:
+#if defined(CONFIG_GICV3)
+	ldr	x0, =GICR_BASE
+	bl	gic_init_secure_percpu
+#elif defined(CONFIG_GICV2)
+	ldr	x0, =GICD_BASE
+	ldr	x1, =GICC_BASE
+	bl	gic_init_secure_percpu
+#endif
+#endif
+
+#ifdef CONFIG_ARMV8_MULTIENTRY
+	branch_if_master x0, x1, 2f
+
+	/*
+	 * Slave should wait for master clearing spin table.
+	 * This sync prevent slaves observing incorrect
+	 * value of spin table and jumping to wrong place.
+	 */
+#if defined(CONFIG_GICV2) || defined(CONFIG_GICV3)
+#ifdef CONFIG_GICV2
+	ldr	x0, =GICC_BASE
+#endif
+	bl	gic_wait_for_interrupt
+#endif
+
+	/*
+	 * All slaves will enter EL2 and optionally EL1.
+	 */
+	adr	x4, lowlevel_in_el2
+	ldr	x5, =ES_TO_AARCH64
+	bl	armv8_switch_to_el2
+
+lowlevel_in_el2:
+#ifdef CONFIG_ARMV8_SWITCH_TO_EL1
+	adr	x4, lowlevel_in_el1
+	ldr	x5, =ES_TO_AARCH64
+	bl	armv8_switch_to_el1
+
+lowlevel_in_el1:
+#endif
+
+#endif /* CONFIG_ARMV8_MULTIENTRY */
+
+2:
+	mov	lr, x29			/* Restore LR */
+	ret
+ENDPROC(lowlevel_init)
-- 
2.19.0