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
28999:	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
37static 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
43static 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
49static 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
58static inline void restore_user_access(unsigned long flags)
59{
60	mtspr(SPRN_MD_AP, flags);
61}
62
63static inline bool
64bad_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