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-rw-r--r--arch/arm64/kernel/cpu-reset.S53
1 files changed, 53 insertions, 0 deletions
diff --git a/arch/arm64/kernel/cpu-reset.S b/arch/arm64/kernel/cpu-reset.S
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+++ b/arch/arm64/kernel/cpu-reset.S
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+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * CPU reset routines
+ *
+ * Copyright (C) 2001 Deep Blue Solutions Ltd.
+ * Copyright (C) 2012 ARM Ltd.
+ * Copyright (C) 2015 Huawei Futurewei Technologies.
+ */
+
+#include <linux/linkage.h>
+#include <linux/cfi_types.h>
+#include <asm/assembler.h>
+#include <asm/sysreg.h>
+#include <asm/virt.h>
+
+.text
+.pushsection .idmap.text, "awx"
+
+/*
+ * cpu_soft_restart(el2_switch, entry, arg0, arg1, arg2)
+ *
+ * @el2_switch: Flag to indicate a switch to EL2 is needed.
+ * @entry: Location to jump to for soft reset.
+ * arg0: First argument passed to @entry. (relocation list)
+ * arg1: Second argument passed to @entry.(physical kernel entry)
+ * arg2: Third argument passed to @entry. (physical dtb address)
+ *
+ * Put the CPU into the same state as it would be if it had been reset, and
+ * branch to what would be the reset vector. It must be executed with the
+ * flat identity mapping.
+ */
+SYM_TYPED_FUNC_START(cpu_soft_restart)
+ mov_q x12, INIT_SCTLR_EL1_MMU_OFF
+ pre_disable_mmu_workaround
+ /*
+ * either disable EL1&0 translation regime or disable EL2&0 translation
+ * regime if HCR_EL2.E2H == 1
+ */
+ msr sctlr_el1, x12
+ isb
+
+ cbz x0, 1f // el2_switch?
+ mov x0, #HVC_SOFT_RESTART
+ hvc #0 // no return
+
+1: mov x8, x1 // entry
+ mov x0, x2 // arg0
+ mov x1, x3 // arg1
+ mov x2, x4 // arg2
+ br x8
+SYM_FUNC_END(cpu_soft_restart)
+
+.popsection