/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef __ASM_ASM_UACCESS_H
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#define __ASM_ASM_UACCESS_H
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#include <asm/alternative-macros.h>
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#include <asm/kernel-pgtable.h>
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#include <asm/mmu.h>
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#include <asm/sysreg.h>
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#include <asm/assembler.h>
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/*
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* User access enabling/disabling macros.
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*/
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#ifdef CONFIG_ARM64_SW_TTBR0_PAN
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.macro __uaccess_ttbr0_disable, tmp1
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mrs \tmp1, ttbr1_el1 // swapper_pg_dir
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bic \tmp1, \tmp1, #TTBR_ASID_MASK
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sub \tmp1, \tmp1, #PAGE_SIZE // reserved_pg_dir just before swapper_pg_dir
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msr ttbr0_el1, \tmp1 // set reserved TTBR0_EL1
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isb
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add \tmp1, \tmp1, #PAGE_SIZE
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msr ttbr1_el1, \tmp1 // set reserved ASID
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isb
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.endm
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.macro __uaccess_ttbr0_enable, tmp1, tmp2
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get_current_task \tmp1
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ldr \tmp1, [\tmp1, #TSK_TI_TTBR0] // load saved TTBR0_EL1
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mrs \tmp2, ttbr1_el1
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extr \tmp2, \tmp2, \tmp1, #48
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ror \tmp2, \tmp2, #16
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msr ttbr1_el1, \tmp2 // set the active ASID
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isb
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msr ttbr0_el1, \tmp1 // set the non-PAN TTBR0_EL1
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isb
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.endm
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.macro uaccess_ttbr0_disable, tmp1, tmp2
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alternative_if_not ARM64_HAS_PAN
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save_and_disable_irq \tmp2 // avoid preemption
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__uaccess_ttbr0_disable \tmp1
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restore_irq \tmp2
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alternative_else_nop_endif
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.endm
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.macro uaccess_ttbr0_enable, tmp1, tmp2, tmp3
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alternative_if_not ARM64_HAS_PAN
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save_and_disable_irq \tmp3 // avoid preemption
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__uaccess_ttbr0_enable \tmp1, \tmp2
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restore_irq \tmp3
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alternative_else_nop_endif
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.endm
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#else
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.macro uaccess_ttbr0_disable, tmp1, tmp2
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.endm
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.macro uaccess_ttbr0_enable, tmp1, tmp2, tmp3
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.endm
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#endif
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/*
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* Generate the assembly for LDTR/STTR with exception table entries.
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* This is complicated as there is no post-increment or pair versions of the
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* unprivileged instructions, and USER() only works for single instructions.
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*/
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.macro uao_ldp l, reg1, reg2, addr, post_inc
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8888: ldtr \reg1, [\addr];
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8889: ldtr \reg2, [\addr, #8];
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add \addr, \addr, \post_inc;
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_asm_extable 8888b,\l;
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_asm_extable 8889b,\l;
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.endm
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.macro uao_stp l, reg1, reg2, addr, post_inc
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8888: sttr \reg1, [\addr];
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8889: sttr \reg2, [\addr, #8];
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add \addr, \addr, \post_inc;
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_asm_extable 8888b,\l;
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_asm_extable 8889b,\l;
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.endm
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.macro uao_user_alternative l, inst, alt_inst, reg, addr, post_inc
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8888: \alt_inst \reg, [\addr];
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add \addr, \addr, \post_inc;
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_asm_extable 8888b,\l;
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.endm
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#endif
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