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d678a59d2d
When bringing in the series 'arm: dts: am62-beagleplay: Fix Beagleplay Ethernet"' I failed to notice that b4 noticed it was based on next and so took that as the base commit and merged that part of next to master. This reverts commitc8ffd1356d, reversing changes made to2ee6f3a5f7. Reported-by: Jonas Karlman <jonas@kwiboo.se> Signed-off-by: Tom Rini <trini@konsulko.com>
58 lines
1.7 KiB
C
58 lines
1.7 KiB
C
// SPDX-License-Identifier: GPL-2.0+
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/*
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* Switch to non-secure mode
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*
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* Copyright (c) 2018 Heinrich Schuchardt
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*
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* This module contains the ARMv8 specific code required to adjust the exception
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* level before booting an operating system.
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*/
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#include <common.h>
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#include <bootm.h>
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#include <cpu_func.h>
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#include <log.h>
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#include <asm/cache.h>
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#include <asm/setjmp.h>
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/**
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* entry_non_secure() - entry point when switching to non-secure mode
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*
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* When switching to non-secure mode switch_to_non_secure_mode() calls this
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* function passing a jump buffer. We use this jump buffer to restore the
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* original stack and register state.
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*
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* @non_secure_jmp: jump buffer for restoring stack and registers
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*/
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static void entry_non_secure(struct jmp_buf_data *non_secure_jmp)
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{
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dcache_enable();
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debug("Reached non-secure mode\n");
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/* Restore stack and registers saved in switch_to_non_secure_mode() */
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longjmp(non_secure_jmp, 1);
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}
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/**
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* switch_to_non_secure_mode() - switch to non-secure mode
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*
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* Exception level EL3 is meant to be used by the secure monitor only (ARM
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* trusted firmware being one embodiment). The operating system shall be
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* started at exception level EL2. So here we check the exception level
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* and switch it if necessary.
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*/
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void switch_to_non_secure_mode(void)
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{
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struct jmp_buf_data non_secure_jmp;
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/* On AArch64 we need to make sure we call our payload in < EL3 */
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if (current_el() == 3) {
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if (setjmp(&non_secure_jmp))
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return;
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dcache_disable(); /* flush cache before switch to EL2 */
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/* Move into EL2 and keep running there */
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armv8_switch_to_el2((uintptr_t)&non_secure_jmp, 0, 0, 0,
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(uintptr_t)entry_non_secure, ES_TO_AARCH64);
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}
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}
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