56 lines
1.4 KiB
Diff
56 lines
1.4 KiB
Diff
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From 252cbd36e51414b60ab68306f9c38e358709494d Mon Sep 17 00:00:00 2001
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From: Jaxson Han <jaxson.han@arm.com>
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Date: Tue, 25 May 2021 07:25:00 +0100
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Subject: [PATCH] aarch64: Prepare for lower EL booting
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Save SPSR_KERNEL into spsr_to_elx during el3_init.
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The jump_kernel will load spsr_to_elx into spsr_el3.
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This change will make it easier to control whether drop to lower EL
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before jumping to the kernel.
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Upstream-Status: Pending
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Signed-off-by: Jaxson Han <jaxson.han@arm.com>
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Reviewed-by: Andre Przywara <andre.przywara@arm.com>
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---
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arch/aarch64/boot.S | 15 +++++++++++++--
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1 file changed, 13 insertions(+), 2 deletions(-)
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diff --git a/arch/aarch64/boot.S b/arch/aarch64/boot.S
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index 5105b41..243198d 100644
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--- a/arch/aarch64/boot.S
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+++ b/arch/aarch64/boot.S
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@@ -151,7 +151,16 @@ el3_init:
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mov x0, #ZCR_EL3_LEN_MAX // SVE: Enable full vector len
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msr ZCR_EL3, x0 // for EL2.
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-1:
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+ /*
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+ * Save SPSR_KERNEL into spsr_to_elx.
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+ * The jump_kernel will load spsr_to_elx into spsr_el3
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+ */
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+1: mov w0, #SPSR_KERNEL
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+ ldr x1, =spsr_to_elx
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+ str w0, [x1]
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+ b el_max_init
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+
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+el_max_init:
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ldr x0, =COUNTER_FREQ
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msr cntfrq_el0, x0
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@@ -199,7 +208,7 @@ ASM_FUNC(jump_kernel)
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b.eq 1f
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br x19 // Keep current EL
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-1: mov x4, #SPSR_KERNEL
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+1: ldr w4, spsr_to_elx
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/*
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* If bit 0 of the kernel address is set, we're entering in AArch32
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@@ -217,3 +226,5 @@ ASM_FUNC(jump_kernel)
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.align 3
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flag_keep_el:
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.long 0
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+spsr_to_elx:
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+ .long 0
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