1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _ASM_POWERPC_KUP_8XX_H_
3 #define _ASM_POWERPC_KUP_8XX_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_save_and_lock sp, thread, gpr1, gpr2, gpr3
13 lis \gpr2, MD_APG_KUAP@h /* only APG0 and APG1 are used */
14 mfspr \gpr1, SPRN_MD_AP
15 mtspr SPRN_MD_AP, \gpr2
16 stw \gpr1, STACK_REGS_KUAP(\sp)
17 .endm
18
19 .macro kuap_restore sp, current, gpr1, gpr2, gpr3
20 lwz \gpr1, STACK_REGS_KUAP(\sp)
21 mtspr SPRN_MD_AP, \gpr1
22 .endm
23
24 .macro kuap_check current, gpr
25 #ifdef CONFIG_PPC_KUAP_DEBUG
26 mfspr \gpr, SPRN_MD_AP
27 rlwinm \gpr, \gpr, 16, 0xffff
28 999: twnei \gpr, MD_APG_KUAP@h
29 EMIT_BUG_ENTRY 999b, __FILE__, __LINE__, (BUGFLAG_WARNING | BUGFLAG_ONCE)
30 #endif
31 .endm
32
33 #else /* !__ASSEMBLY__ */
34
35 #include <asm/reg.h>
36
allow_user_access(void __user * to,const void __user * from,unsigned long size,unsigned long dir)37 static inline void allow_user_access(void __user *to, const void __user *from,
38 unsigned long size, unsigned long dir)
39 {
40 mtspr(SPRN_MD_AP, MD_APG_INIT);
41 }
42
prevent_user_access(void __user * to,const void __user * from,unsigned long size,unsigned long dir)43 static inline void prevent_user_access(void __user *to, const void __user *from,
44 unsigned long size, unsigned long dir)
45 {
46 mtspr(SPRN_MD_AP, MD_APG_KUAP);
47 }
48
prevent_user_access_return(void)49 static inline unsigned long prevent_user_access_return(void)
50 {
51 unsigned long flags = mfspr(SPRN_MD_AP);
52
53 mtspr(SPRN_MD_AP, MD_APG_KUAP);
54
55 return flags;
56 }
57
restore_user_access(unsigned long flags)58 static inline void restore_user_access(unsigned long flags)
59 {
60 mtspr(SPRN_MD_AP, flags);
61 }
62
63 static inline bool
bad_kuap_fault(struct pt_regs * regs,unsigned long address,bool is_write)64 bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)
65 {
66 return WARN(!((regs->kuap ^ MD_APG_KUAP) & 0xff000000),
67 "Bug: fault blocked by AP register !");
68 }
69
70 #endif /* !__ASSEMBLY__ */
71
72 #endif /* CONFIG_PPC_KUAP */
73
74 #endif /* _ASM_POWERPC_KUP_8XX_H_ */
75