/* SPDX-License-Identifier: GPL-2.0-only */
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/*
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* Based on arch/arm/mm/proc.S
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*
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* Copyright (C) 2001 Deep Blue Solutions Ltd.
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* Copyright (C) 2012 ARM Ltd.
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* Author: Catalin Marinas <catalin.marinas@arm.com>
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*/
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#include <linux/init.h>
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#include <linux/linkage.h>
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#include <linux/pgtable.h>
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#include <asm/assembler.h>
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#include <asm/asm-offsets.h>
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#include <asm/asm_pointer_auth.h>
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#include <asm/hwcap.h>
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#include <asm/pgtable-hwdef.h>
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#include <asm/cpufeature.h>
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#include <asm/alternative.h>
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#include <asm/smp.h>
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#include <asm/sysreg.h>
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#ifdef CONFIG_ARM64_64K_PAGES
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#define TCR_TG_FLAGS TCR_TG0_64K | TCR_TG1_64K
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#elif defined(CONFIG_ARM64_16K_PAGES)
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#define TCR_TG_FLAGS TCR_TG0_16K | TCR_TG1_16K
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#else /* CONFIG_ARM64_4K_PAGES */
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#define TCR_TG_FLAGS TCR_TG0_4K | TCR_TG1_4K
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#endif
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#ifdef CONFIG_RANDOMIZE_BASE
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#define TCR_KASLR_FLAGS TCR_NFD1
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#else
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#define TCR_KASLR_FLAGS 0
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#endif
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#define TCR_SMP_FLAGS TCR_SHARED
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/* PTWs cacheable, inner/outer WBWA */
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#define TCR_CACHE_FLAGS TCR_IRGN_WBWA | TCR_ORGN_WBWA
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#ifdef CONFIG_KASAN_SW_TAGS
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#define TCR_KASAN_SW_FLAGS TCR_TBI1 | TCR_TBID1
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#else
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#define TCR_KASAN_SW_FLAGS 0
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#endif
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#ifdef CONFIG_KASAN_HW_TAGS
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#define TCR_MTE_FLAGS SYS_TCR_EL1_TCMA1 | TCR_TBI1 | TCR_TBID1
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#else
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/*
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* The mte_zero_clear_page_tags() implementation uses DC GZVA, which relies on
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* TBI being enabled at EL1.
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*/
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#define TCR_MTE_FLAGS TCR_TBI1 | TCR_TBID1
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#endif
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/*
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* Default MAIR_EL1. MT_NORMAL_TAGGED is initially mapped as Normal memory and
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* changed during __cpu_setup to Normal Tagged if the system supports MTE.
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*/
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#define MAIR_EL1_SET \
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(MAIR_ATTRIDX(MAIR_ATTR_DEVICE_nGnRnE, MT_DEVICE_nGnRnE) | \
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MAIR_ATTRIDX(MAIR_ATTR_DEVICE_nGnRE, MT_DEVICE_nGnRE) | \
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MAIR_ATTRIDX(MAIR_ATTR_DEVICE_GRE, MT_DEVICE_GRE) | \
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MAIR_ATTRIDX(MAIR_ATTR_NORMAL_NC, MT_NORMAL_NC) | \
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MAIR_ATTRIDX(MAIR_ATTR_NORMAL, MT_NORMAL) | \
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MAIR_ATTRIDX(MAIR_ATTR_NORMAL_WT, MT_NORMAL_WT) | \
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MAIR_ATTRIDX(MAIR_ATTR_NORMAL, MT_NORMAL_TAGGED) | \
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MAIR_ATTRIDX(MAIR_ATTR_NORMAL_iNC_oWB, MT_NORMAL_iNC_oWB))
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#ifdef CONFIG_CPU_PM
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/**
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* cpu_do_suspend - save CPU registers context
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*
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* x0: virtual address of context pointer
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*
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* This must be kept in sync with struct cpu_suspend_ctx in <asm/suspend.h>.
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*/
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SYM_FUNC_START(cpu_do_suspend)
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mrs x2, tpidr_el0
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mrs x3, tpidrro_el0
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mrs x4, contextidr_el1
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mrs x5, osdlr_el1
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mrs x6, cpacr_el1
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mrs x7, tcr_el1
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mrs x8, vbar_el1
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mrs x9, mdscr_el1
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mrs x10, oslsr_el1
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mrs x11, sctlr_el1
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alternative_if_not ARM64_HAS_VIRT_HOST_EXTN
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mrs x12, tpidr_el1
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alternative_else
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mrs x12, tpidr_el2
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alternative_endif
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mrs x13, sp_el0
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stp x2, x3, [x0]
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stp x4, x5, [x0, #16]
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stp x6, x7, [x0, #32]
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stp x8, x9, [x0, #48]
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stp x10, x11, [x0, #64]
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stp x12, x13, [x0, #80]
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/*
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* Save x18 as it may be used as a platform register, e.g. by shadow
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* call stack.
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*/
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str x18, [x0, #96]
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ret
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SYM_FUNC_END(cpu_do_suspend)
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/**
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* cpu_do_resume - restore CPU register context
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*
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* x0: Address of context pointer
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*/
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.pushsection ".idmap.text", "awx"
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SYM_FUNC_START(cpu_do_resume)
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ldp x2, x3, [x0]
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ldp x4, x5, [x0, #16]
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ldp x6, x8, [x0, #32]
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ldp x9, x10, [x0, #48]
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ldp x11, x12, [x0, #64]
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ldp x13, x14, [x0, #80]
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/*
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* Restore x18, as it may be used as a platform register, and clear
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* the buffer to minimize the risk of exposure when used for shadow
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* call stack.
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*/
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ldr x18, [x0, #96]
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str xzr, [x0, #96]
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msr tpidr_el0, x2
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msr tpidrro_el0, x3
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msr contextidr_el1, x4
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msr cpacr_el1, x6
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/* Don't change t0sz here, mask those bits when restoring */
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mrs x7, tcr_el1
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bfi x8, x7, TCR_T0SZ_OFFSET, TCR_TxSZ_WIDTH
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msr tcr_el1, x8
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msr vbar_el1, x9
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/*
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* __cpu_setup() cleared MDSCR_EL1.MDE and friends, before unmasking
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* debug exceptions. By restoring MDSCR_EL1 here, we may take a debug
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* exception. Mask them until local_daif_restore() in cpu_suspend()
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* resets them.
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*/
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disable_daif
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msr mdscr_el1, x10
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msr sctlr_el1, x12
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alternative_if_not ARM64_HAS_VIRT_HOST_EXTN
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msr tpidr_el1, x13
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alternative_else
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msr tpidr_el2, x13
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alternative_endif
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msr sp_el0, x14
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/*
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* Restore oslsr_el1 by writing oslar_el1
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*/
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msr osdlr_el1, x5
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ubfx x11, x11, #1, #1
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msr oslar_el1, x11
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reset_pmuserenr_el0 x0 // Disable PMU access from EL0
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reset_amuserenr_el0 x0 // Disable AMU access from EL0
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alternative_if ARM64_HAS_RAS_EXTN
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msr_s SYS_DISR_EL1, xzr
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alternative_else_nop_endif
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ptrauth_keys_install_kernel_nosync x14, x1, x2, x3
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isb
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ret
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SYM_FUNC_END(cpu_do_resume)
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.popsection
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#endif
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.pushsection ".idmap.text", "awx"
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.macro __idmap_cpu_set_reserved_ttbr1, tmp1, tmp2
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adrp \tmp1, reserved_pg_dir
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phys_to_ttbr \tmp2, \tmp1
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offset_ttbr1 \tmp2, \tmp1
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msr ttbr1_el1, \tmp2
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isb
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tlbi vmalle1
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dsb nsh
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isb
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.endm
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/*
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* void idmap_cpu_replace_ttbr1(phys_addr_t ttbr1)
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*
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* This is the low-level counterpart to cpu_replace_ttbr1, and should not be
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* called by anything else. It can only be executed from a TTBR0 mapping.
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*/
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SYM_FUNC_START(idmap_cpu_replace_ttbr1)
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save_and_disable_daif flags=x2
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__idmap_cpu_set_reserved_ttbr1 x1, x3
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offset_ttbr1 x0, x3
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msr ttbr1_el1, x0
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isb
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restore_daif x2
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ret
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SYM_FUNC_END(idmap_cpu_replace_ttbr1)
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.popsection
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#ifdef CONFIG_UNMAP_KERNEL_AT_EL0
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.pushsection ".idmap.text", "awx"
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.macro __idmap_kpti_get_pgtable_ent, type
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dc cvac, cur_\()\type\()p // Ensure any existing dirty
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dmb sy // lines are written back before
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ldr \type, [cur_\()\type\()p] // loading the entry
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tbz \type, #0, skip_\()\type // Skip invalid and
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tbnz \type, #11, skip_\()\type // non-global entries
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.endm
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.macro __idmap_kpti_put_pgtable_ent_ng, type
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orr \type, \type, #PTE_NG // Same bit for blocks and pages
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str \type, [cur_\()\type\()p] // Update the entry and ensure
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dmb sy // that it is visible to all
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dc civac, cur_\()\type\()p // CPUs.
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.endm
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/*
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* void __kpti_install_ng_mappings(int cpu, int num_cpus, phys_addr_t swapper)
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*
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* Called exactly once from stop_machine context by each CPU found during boot.
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*/
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__idmap_kpti_flag:
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.long 1
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SYM_FUNC_START(idmap_kpti_install_ng_mappings)
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cpu .req w0
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num_cpus .req w1
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swapper_pa .req x2
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swapper_ttb .req x3
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flag_ptr .req x4
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cur_pgdp .req x5
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end_pgdp .req x6
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pgd .req x7
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cur_pudp .req x8
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end_pudp .req x9
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pud .req x10
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cur_pmdp .req x11
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end_pmdp .req x12
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pmd .req x13
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cur_ptep .req x14
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end_ptep .req x15
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pte .req x16
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mrs swapper_ttb, ttbr1_el1
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restore_ttbr1 swapper_ttb
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adr flag_ptr, __idmap_kpti_flag
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cbnz cpu, __idmap_kpti_secondary
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/* We're the boot CPU. Wait for the others to catch up */
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sevl
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1: wfe
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ldaxr w17, [flag_ptr]
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eor w17, w17, num_cpus
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cbnz w17, 1b
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/* We need to walk swapper, so turn off the MMU. */
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pre_disable_mmu_workaround
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mrs x17, sctlr_el1
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bic x17, x17, #SCTLR_ELx_M
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msr sctlr_el1, x17
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isb
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/* Everybody is enjoying the idmap, so we can rewrite swapper. */
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/* PGD */
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mov cur_pgdp, swapper_pa
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add end_pgdp, cur_pgdp, #(PTRS_PER_PGD * 8)
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do_pgd: __idmap_kpti_get_pgtable_ent pgd
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tbnz pgd, #1, walk_puds
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next_pgd:
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__idmap_kpti_put_pgtable_ent_ng pgd
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skip_pgd:
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add cur_pgdp, cur_pgdp, #8
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cmp cur_pgdp, end_pgdp
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b.ne do_pgd
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/* Publish the updated tables and nuke all the TLBs */
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dsb sy
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tlbi vmalle1is
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dsb ish
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isb
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/* We're done: fire up the MMU again */
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mrs x17, sctlr_el1
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orr x17, x17, #SCTLR_ELx_M
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set_sctlr_el1 x17
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/* Set the flag to zero to indicate that we're all done */
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str wzr, [flag_ptr]
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ret
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/* PUD */
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walk_puds:
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.if CONFIG_PGTABLE_LEVELS > 3
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pte_to_phys cur_pudp, pgd
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add end_pudp, cur_pudp, #(PTRS_PER_PUD * 8)
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do_pud: __idmap_kpti_get_pgtable_ent pud
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tbnz pud, #1, walk_pmds
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next_pud:
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__idmap_kpti_put_pgtable_ent_ng pud
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skip_pud:
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add cur_pudp, cur_pudp, 8
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cmp cur_pudp, end_pudp
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b.ne do_pud
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b next_pgd
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.else /* CONFIG_PGTABLE_LEVELS <= 3 */
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mov pud, pgd
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b walk_pmds
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next_pud:
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b next_pgd
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.endif
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/* PMD */
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walk_pmds:
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.if CONFIG_PGTABLE_LEVELS > 2
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pte_to_phys cur_pmdp, pud
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add end_pmdp, cur_pmdp, #(PTRS_PER_PMD * 8)
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do_pmd: __idmap_kpti_get_pgtable_ent pmd
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tbnz pmd, #1, walk_ptes
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next_pmd:
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__idmap_kpti_put_pgtable_ent_ng pmd
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skip_pmd:
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add cur_pmdp, cur_pmdp, #8
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cmp cur_pmdp, end_pmdp
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b.ne do_pmd
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b next_pud
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.else /* CONFIG_PGTABLE_LEVELS <= 2 */
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mov pmd, pud
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b walk_ptes
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next_pmd:
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b next_pud
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.endif
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/* PTE */
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walk_ptes:
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pte_to_phys cur_ptep, pmd
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add end_ptep, cur_ptep, #(PTRS_PER_PTE * 8)
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do_pte: __idmap_kpti_get_pgtable_ent pte
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__idmap_kpti_put_pgtable_ent_ng pte
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skip_pte:
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add cur_ptep, cur_ptep, #8
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cmp cur_ptep, end_ptep
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b.ne do_pte
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b next_pmd
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.unreq cpu
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.unreq num_cpus
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.unreq swapper_pa
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.unreq cur_pgdp
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.unreq end_pgdp
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.unreq pgd
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.unreq cur_pudp
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.unreq end_pudp
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.unreq pud
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.unreq cur_pmdp
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.unreq end_pmdp
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.unreq pmd
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.unreq cur_ptep
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.unreq end_ptep
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.unreq pte
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/* Secondary CPUs end up here */
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__idmap_kpti_secondary:
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/* Uninstall swapper before surgery begins */
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__idmap_cpu_set_reserved_ttbr1 x16, x17
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/* Increment the flag to let the boot CPU we're ready */
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1: ldxr w16, [flag_ptr]
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add w16, w16, #1
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stxr w17, w16, [flag_ptr]
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cbnz w17, 1b
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/* Wait for the boot CPU to finish messing around with swapper */
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sevl
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1: wfe
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ldxr w16, [flag_ptr]
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cbnz w16, 1b
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/* All done, act like nothing happened */
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offset_ttbr1 swapper_ttb, x16
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msr ttbr1_el1, swapper_ttb
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isb
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ret
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.unreq swapper_ttb
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.unreq flag_ptr
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SYM_FUNC_END(idmap_kpti_install_ng_mappings)
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.popsection
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#endif
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/*
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* __cpu_setup
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*
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* Initialise the processor for turning the MMU on.
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*
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* Output:
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* Return in x0 the value of the SCTLR_EL1 register.
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*/
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.pushsection ".idmap.text", "awx"
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SYM_FUNC_START(__cpu_setup)
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tlbi vmalle1 // Invalidate local TLB
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dsb nsh
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mov x1, #3 << 20
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msr cpacr_el1, x1 // Enable FP/ASIMD
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mov x1, #1 << 12 // Reset mdscr_el1 and disable
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msr mdscr_el1, x1 // access to the DCC from EL0
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isb // Unmask debug exceptions now,
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enable_dbg // since this is per-cpu
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reset_pmuserenr_el0 x1 // Disable PMU access from EL0
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reset_amuserenr_el0 x1 // Disable AMU access from EL0
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/*
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* Memory region attributes
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*/
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mov_q x5, MAIR_EL1_SET
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#ifdef CONFIG_ARM64_MTE
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mte_tcr .req x20
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mov mte_tcr, #0
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/*
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* Update MAIR_EL1, GCR_EL1 and TFSR*_EL1 if MTE is supported
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* (ID_AA64PFR1_EL1[11:8] > 1).
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*/
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mrs x10, ID_AA64PFR1_EL1
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ubfx x10, x10, #ID_AA64PFR1_MTE_SHIFT, #4
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cmp x10, #ID_AA64PFR1_MTE
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b.lt 1f
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/* Normal Tagged memory type at the corresponding MAIR index */
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mov x10, #MAIR_ATTR_NORMAL_TAGGED
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bfi x5, x10, #(8 * MT_NORMAL_TAGGED), #8
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mov x10, #KERNEL_GCR_EL1
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msr_s SYS_GCR_EL1, x10
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/*
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* If GCR_EL1.RRND=1 is implemented the same way as RRND=0, then
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* RGSR_EL1.SEED must be non-zero for IRG to produce
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* pseudorandom numbers. As RGSR_EL1 is UNKNOWN out of reset, we
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* must initialize it.
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*/
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mrs x10, CNTVCT_EL0
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ands x10, x10, #SYS_RGSR_EL1_SEED_MASK
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csinc x10, x10, xzr, ne
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lsl x10, x10, #SYS_RGSR_EL1_SEED_SHIFT
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msr_s SYS_RGSR_EL1, x10
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/* clear any pending tag check faults in TFSR*_EL1 */
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msr_s SYS_TFSR_EL1, xzr
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msr_s SYS_TFSRE0_EL1, xzr
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/* set the TCR_EL1 bits */
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mov_q mte_tcr, TCR_MTE_FLAGS
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1:
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#endif
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msr mair_el1, x5
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/*
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* Set/prepare TCR and TTBR. TCR_EL1.T1SZ gets further
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* adjusted if the kernel is compiled with 52bit VA support.
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*/
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mov_q x10, TCR_TxSZ(VA_BITS) | TCR_CACHE_FLAGS | TCR_SMP_FLAGS | \
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TCR_TG_FLAGS | TCR_KASLR_FLAGS | TCR_ASID16 | \
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TCR_TBI0 | TCR_A1 | TCR_KASAN_SW_FLAGS
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#ifdef CONFIG_ARM64_MTE
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orr x10, x10, mte_tcr
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.unreq mte_tcr
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#endif
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tcr_clear_errata_bits x10, x9, x5
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#ifdef CONFIG_ARM64_VA_BITS_52
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ldr_l x9, vabits_actual
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sub x9, xzr, x9
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add x9, x9, #64
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tcr_set_t1sz x10, x9
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#else
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ldr_l x9, idmap_t0sz
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#endif
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tcr_set_t0sz x10, x9
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/*
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* Set the IPS bits in TCR_EL1.
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*/
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tcr_compute_pa_size x10, #TCR_IPS_SHIFT, x5, x6
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#ifdef CONFIG_ARM64_HW_AFDBM
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/*
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* Enable hardware update of the Access Flags bit.
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* Hardware dirty bit management is enabled later,
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* via capabilities.
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*/
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mrs x9, ID_AA64MMFR1_EL1
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and x9, x9, #0xf
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cbz x9, 1f
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orr x10, x10, #TCR_HA // hardware Access flag update
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1:
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#endif /* CONFIG_ARM64_HW_AFDBM */
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msr tcr_el1, x10
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/*
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* Prepare SCTLR
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*/
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mov_q x0, INIT_SCTLR_EL1_MMU_ON
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ret // return to head.S
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SYM_FUNC_END(__cpu_setup)
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