1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef __ASM_ASM_UACCESS_H 3 #define __ASM_ASM_UACCESS_H 4 5 #include <asm/alternative-macros.h> 6 #include <asm/asm-extable.h> 7 #include <asm/assembler.h> 8 #include <asm/kernel-pgtable.h> 9 #include <asm/mmu.h> 10 #include <asm/sysreg.h> 11 12 /* 13 * User access enabling/disabling macros. 14 */ 15 #ifdef CONFIG_ARM64_SW_TTBR0_PAN 16 .macro __uaccess_ttbr0_disable, tmp1 17 mrs \tmp1, ttbr1_el1 // swapper_pg_dir 18 bic \tmp1, \tmp1, #TTBR_ASID_MASK 19 sub \tmp1, \tmp1, #RESERVED_SWAPPER_OFFSET // reserved_pg_dir 20 msr ttbr0_el1, \tmp1 // set reserved TTBR0_EL1 21 isb 22 add \tmp1, \tmp1, #RESERVED_SWAPPER_OFFSET 23 msr ttbr1_el1, \tmp1 // set reserved ASID 24 isb 25 .endm 26 27 .macro __uaccess_ttbr0_enable, tmp1, tmp2 28 get_current_task \tmp1 29 ldr \tmp1, [\tmp1, #TSK_TI_TTBR0] // load saved TTBR0_EL1 30 mrs \tmp2, ttbr1_el1 31 extr \tmp2, \tmp2, \tmp1, #48 32 ror \tmp2, \tmp2, #16 33 msr ttbr1_el1, \tmp2 // set the active ASID 34 isb 35 msr ttbr0_el1, \tmp1 // set the non-PAN TTBR0_EL1 36 isb 37 .endm 38 39 .macro uaccess_ttbr0_disable, tmp1, tmp2 40 alternative_if_not ARM64_HAS_PAN 41 save_and_disable_irq \tmp2 // avoid preemption 42 __uaccess_ttbr0_disable \tmp1 43 restore_irq \tmp2 44 alternative_else_nop_endif 45 .endm 46 47 .macro uaccess_ttbr0_enable, tmp1, tmp2, tmp3 48 alternative_if_not ARM64_HAS_PAN 49 save_and_disable_irq \tmp3 // avoid preemption 50 __uaccess_ttbr0_enable \tmp1, \tmp2 51 restore_irq \tmp3 52 alternative_else_nop_endif 53 .endm 54 #else 55 .macro uaccess_ttbr0_disable, tmp1, tmp2 56 .endm 57 58 .macro uaccess_ttbr0_enable, tmp1, tmp2, tmp3 59 .endm 60 #endif 61 62 #define USER(l, x...) \ 63 9999: x; \ 64 _asm_extable 9999b, l 65 66 /* 67 * Generate the assembly for LDTR/STTR with exception table entries. 68 * This is complicated as there is no post-increment or pair versions of the 69 * unprivileged instructions, and USER() only works for single instructions. 70 */ 71 .macro user_ldp l, reg1, reg2, addr, post_inc 72 8888: ldtr \reg1, [\addr]; 73 8889: ldtr \reg2, [\addr, #8]; 74 add \addr, \addr, \post_inc; 75 76 _asm_extable 8888b,\l; 77 _asm_extable 8889b,\l; 78 .endm 79 80 .macro user_stp l, reg1, reg2, addr, post_inc 81 8888: sttr \reg1, [\addr]; 82 8889: sttr \reg2, [\addr, #8]; 83 add \addr, \addr, \post_inc; 84 85 _asm_extable 8888b,\l; 86 _asm_extable 8889b,\l; 87 .endm 88 89 .macro user_ldst l, inst, reg, addr, post_inc 90 8888: \inst \reg, [\addr]; 91 add \addr, \addr, \post_inc; 92 93 _asm_extable 8888b,\l; 94 .endm 95 #endif 96