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 #ifndef __ASSEMBLY__
11
12 #include <asm/reg.h>
13
14 static __always_inline void __kuap_save_and_lock(struct pt_regs *regs)
15 {
16 regs->kuap = mfspr(SPRN_MD_AP);
17 mtspr(SPRN_MD_AP, MD_APG_KUAP);
18 }
19 #define __kuap_save_and_lock __kuap_save_and_lock
20
21 static __always_inline void kuap_user_restore(struct pt_regs *regs)
22 {
23 }
24
25 static __always_inline void __kuap_kernel_restore(struct pt_regs *regs, unsigned long kuap)
26 {
27 mtspr(SPRN_MD_AP, regs->kuap);
28 }
29
30 #ifdef CONFIG_PPC_KUAP_DEBUG
31 static __always_inline unsigned long __kuap_get_and_assert_locked(void)
32 {
33 WARN_ON_ONCE(mfspr(SPRN_MD_AP) >> 16 != MD_APG_KUAP >> 16);
34
35 return 0;
36 }
37 #define __kuap_get_and_assert_locked __kuap_get_and_assert_locked
38 #endif
39
40 static __always_inline void uaccess_begin_8xx(unsigned long val)
41 {
42 asm(ASM_MMU_FTR_IFSET("mtspr %0, %1", "", %2) : :
43 "i"(SPRN_MD_AP), "r"(val), "i"(MMU_FTR_KUAP) : "memory");
44 }
45
46 static __always_inline void uaccess_end_8xx(void)
47 {
48 asm(ASM_MMU_FTR_IFSET("mtspr %0, %1", "", %2) : :
49 "i"(SPRN_MD_AP), "r"(MD_APG_KUAP), "i"(MMU_FTR_KUAP) : "memory");
50 }
51
52 static __always_inline void allow_user_access(void __user *to, const void __user *from,
53 unsigned long size, unsigned long dir)
54 {
55 uaccess_begin_8xx(MD_APG_INIT);
56 }
57
58 static __always_inline void prevent_user_access(unsigned long dir)
59 {
60 uaccess_end_8xx();
61 }
62
63 static __always_inline unsigned long prevent_user_access_return(void)
64 {
65 unsigned long flags;
66
67 flags = mfspr(SPRN_MD_AP);
68
69 uaccess_end_8xx();
70
71 return flags;
72 }
73
74 static __always_inline void restore_user_access(unsigned long flags)
75 {
76 uaccess_begin_8xx(flags);
77 }
78
79 static __always_inline bool
80 __bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)
81 {
82 return !((regs->kuap ^ MD_APG_KUAP) & 0xff000000);
83 }
84
85 #endif /* !__ASSEMBLY__ */
86
87 #endif /* CONFIG_PPC_KUAP */
88
89 #endif /* _ASM_POWERPC_KUP_8XX_H_ */
90
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