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 add \tmp1, \tmp1, #RESERVED_SWAPPER_OFFSET 22 msr ttbr1_el1, \tmp1 // set reserved ASID 23 isb 24 .endm 25 26 .macro __uaccess_ttbr0_enable, tmp1, tmp2 27 get_current_task \tmp1 28 ldr \tmp1, [\tmp1, #TSK_TI_TTBR0] // load saved TTBR0_EL1 29 mrs \tmp2, ttbr1_el1 30 extr \tmp2, \tmp2, \tmp1, #48 31 ror \tmp2, \tmp2, #16 32 msr ttbr1_el1, \tmp2 // set the active ASID 33 msr ttbr0_el1, \tmp1 // set the non-PAN TTBR0_EL1 34 isb 35 .endm 36 37 .macro uaccess_ttbr0_disable, tmp1, tmp2 38 alternative_if_not ARM64_HAS_PAN 39 save_and_disable_irq \tmp2 // avoid preemption 40 __uaccess_ttbr0_disable \tmp1 41 restore_irq \tmp2 42 alternative_else_nop_endif 43 .endm 44 45 .macro uaccess_ttbr0_enable, tmp1, tmp2, tmp3 46 alternative_if_not ARM64_HAS_PAN 47 save_and_disable_irq \tmp3 // avoid preemption 48 __uaccess_ttbr0_enable \tmp1, \tmp2 49 restore_irq \tmp3 50 alternative_else_nop_endif 51 .endm 52 #else 53 .macro uaccess_ttbr0_disable, tmp1, tmp2 54 .endm 55 56 .macro uaccess_ttbr0_enable, tmp1, tmp2, tmp3 57 .endm 58 #endif 59 60 #define USER(l, x...) \ 61 9999: x; \ 62 _asm_extable_uaccess 9999b, l 63 64 /* 65 * Generate the assembly for LDTR/STTR with exception table entries. 66 * This is complicated as there is no post-increment or pair versions of the 67 * unprivileged instructions, and USER() only works for single instructions. 68 */ 69 .macro user_ldp l, reg1, reg2, addr, post_inc 70 8888: ldtr \reg1, [\addr]; 71 8889: ldtr \reg2, [\addr, #8]; 72 add \addr, \addr, \post_inc; 73 74 _asm_extable_uaccess 8888b, \l; 75 _asm_extable_uaccess 8889b, \l; 76 .endm 77 78 .macro user_stp l, reg1, reg2, addr, post_inc 79 8888: sttr \reg1, [\addr]; 80 8889: sttr \reg2, [\addr, #8]; 81 add \addr, \addr, \post_inc; 82 83 _asm_extable_uaccess 8888b,\l; 84 _asm_extable_uaccess 8889b,\l; 85 .endm 86 87 .macro user_ldst l, inst, reg, addr, post_inc 88 8888: \inst \reg, [\addr]; 89 add \addr, \addr, \post_inc; 90 91 _asm_extable_uaccess 8888b, \l; 92 .endm 93 #endif 94