1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef __ASM_ASM_UACCESS_H 3 #define __ASM_ASM_UACCESS_H 4 5 #include <asm/alternative.h> 6 #include <asm/kernel-pgtable.h> 7 #include <asm/mmu.h> 8 #include <asm/sysreg.h> 9 #include <asm/assembler.h> 10 11 /* 12 * User access enabling/disabling macros. 13 */ 14 #ifdef CONFIG_ARM64_SW_TTBR0_PAN 15 .macro __uaccess_ttbr0_disable, tmp1 16 mrs \tmp1, ttbr1_el1 // swapper_pg_dir 17 bic \tmp1, \tmp1, #TTBR_ASID_MASK 18 sub \tmp1, \tmp1, #RESERVED_TTBR0_SIZE // reserved_ttbr0 just before swapper_pg_dir 19 msr ttbr0_el1, \tmp1 // set reserved TTBR0_EL1 20 isb 21 add \tmp1, \tmp1, #RESERVED_TTBR0_SIZE 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 isb 34 msr ttbr0_el1, \tmp1 // set the non-PAN TTBR0_EL1 35 isb 36 .endm 37 38 .macro uaccess_ttbr0_disable, tmp1, tmp2 39 alternative_if_not ARM64_HAS_PAN 40 save_and_disable_irq \tmp2 // avoid preemption 41 __uaccess_ttbr0_disable \tmp1 42 restore_irq \tmp2 43 alternative_else_nop_endif 44 .endm 45 46 .macro uaccess_ttbr0_enable, tmp1, tmp2, tmp3 47 alternative_if_not ARM64_HAS_PAN 48 save_and_disable_irq \tmp3 // avoid preemption 49 __uaccess_ttbr0_enable \tmp1, \tmp2 50 restore_irq \tmp3 51 alternative_else_nop_endif 52 .endm 53 #else 54 .macro uaccess_ttbr0_disable, tmp1, tmp2 55 .endm 56 57 .macro uaccess_ttbr0_enable, tmp1, tmp2, tmp3 58 .endm 59 #endif 60 61 /* 62 * These macros are no-ops when UAO is present. 63 */ 64 .macro uaccess_disable_not_uao, tmp1, tmp2 65 uaccess_ttbr0_disable \tmp1, \tmp2 66 alternative_if ARM64_ALT_PAN_NOT_UAO 67 SET_PSTATE_PAN(1) 68 alternative_else_nop_endif 69 .endm 70 71 .macro uaccess_enable_not_uao, tmp1, tmp2, tmp3 72 uaccess_ttbr0_enable \tmp1, \tmp2, \tmp3 73 alternative_if ARM64_ALT_PAN_NOT_UAO 74 SET_PSTATE_PAN(0) 75 alternative_else_nop_endif 76 .endm 77 78 /* 79 * Remove the address tag from a virtual address, if present. 80 */ 81 .macro clear_address_tag, dst, addr 82 tst \addr, #(1 << 55) 83 bic \dst, \addr, #(0xff << 56) 84 csel \dst, \dst, \addr, eq 85 .endm 86 87 #endif 88