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 
37 static inline void allow_user_access(void __user *to, const void __user *from,
38 				     unsigned long size)
39 {
40 	mtspr(SPRN_MD_AP, MD_APG_INIT);
41 }
42 
43 static inline void prevent_user_access(void __user *to, const void __user *from,
44 				       unsigned long size)
45 {
46 	mtspr(SPRN_MD_AP, MD_APG_KUAP);
47 }
48 
49 static inline bool bad_kuap_fault(struct pt_regs *regs, bool is_write)
50 {
51 	return WARN(!((regs->kuap ^ MD_APG_KUAP) & 0xf0000000),
52 		    "Bug: fault blocked by AP register !");
53 }
54 
55 #endif /* !__ASSEMBLY__ */
56 
57 #endif /* CONFIG_PPC_KUAP */
58 
59 #endif /* _ASM_POWERPC_KUP_8XX_H_ */
60