1/* SPDX-License-Identifier: GPL-2.0 */ 2#ifndef _ASM_POWERPC_KUP_BOOKE_H_ 3#define _ASM_POWERPC_KUP_BOOKE_H_ 4 5#include <asm/bug.h> 6#include <asm/mmu.h> 7 8#ifdef CONFIG_PPC_KUAP 9 10#ifdef __ASSEMBLY__ 11 12.macro kuap_check_amr gpr1, gpr2 13.endm 14 15#else 16 17#include <linux/sched.h> 18 19#include <asm/reg.h> 20 21static __always_inline void __kuap_lock(void) 22{ 23 mtspr(SPRN_PID, 0); 24 isync(); 25} 26#define __kuap_lock __kuap_lock 27 28static __always_inline void __kuap_save_and_lock(struct pt_regs *regs) 29{ 30 regs->kuap = mfspr(SPRN_PID); 31 mtspr(SPRN_PID, 0); 32 isync(); 33} 34#define __kuap_save_and_lock __kuap_save_and_lock 35 36static __always_inline void kuap_user_restore(struct pt_regs *regs) 37{ 38 if (kuap_is_disabled()) 39 return; 40 41 mtspr(SPRN_PID, current->thread.pid); 42 43 /* Context synchronisation is performed by rfi */ 44} 45 46static __always_inline void __kuap_kernel_restore(struct pt_regs *regs, unsigned long kuap) 47{ 48 if (regs->kuap) 49 mtspr(SPRN_PID, current->thread.pid); 50 51 /* Context synchronisation is performed by rfi */ 52} 53 54#ifdef CONFIG_PPC_KUAP_DEBUG 55static __always_inline unsigned long __kuap_get_and_assert_locked(void) 56{ 57 WARN_ON_ONCE(mfspr(SPRN_PID)); 58 59 return 0; 60} 61#define __kuap_get_and_assert_locked __kuap_get_and_assert_locked 62#endif 63 64static __always_inline void uaccess_begin_booke(unsigned long val) 65{ 66 asm(ASM_MMU_FTR_IFSET("mtspr %0, %1; isync", "", %2) : : 67 "i"(SPRN_PID), "r"(val), "i"(MMU_FTR_KUAP) : "memory"); 68} 69 70static __always_inline void uaccess_end_booke(void) 71{ 72 asm(ASM_MMU_FTR_IFSET("mtspr %0, %1; isync", "", %2) : : 73 "i"(SPRN_PID), "r"(0), "i"(MMU_FTR_KUAP) : "memory"); 74} 75 76static __always_inline void allow_user_access(void __user *to, const void __user *from, 77 unsigned long size, unsigned long dir) 78{ 79 uaccess_begin_booke(current->thread.pid); 80} 81 82static __always_inline void prevent_user_access(unsigned long dir) 83{ 84 uaccess_end_booke(); 85} 86 87static __always_inline unsigned long prevent_user_access_return(void) 88{ 89 unsigned long flags = mfspr(SPRN_PID); 90 91 uaccess_end_booke(); 92 93 return flags; 94} 95 96static __always_inline void restore_user_access(unsigned long flags) 97{ 98 if (flags) 99 uaccess_begin_booke(current->thread.pid); 100} 101 102static __always_inline bool 103__bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write) 104{ 105 return !regs->kuap; 106} 107 108#endif /* !__ASSEMBLY__ */ 109 110#endif /* CONFIG_PPC_KUAP */ 111 112#endif /* _ASM_POWERPC_KUP_BOOKE_H_ */ 113