1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3 * Macros for Flexible Return and Event Delivery (FRED)
4 */
5
6 #ifndef ASM_X86_FRED_H
7 #define ASM_X86_FRED_H
8
9 #include <linux/const.h>
10
11 #include <asm/asm.h>
12 #include <asm/trapnr.h>
13
14 /*
15 * FRED event return instruction opcodes for ERET{S,U}; supported in
16 * binutils >= 2.41.
17 */
18 #define ERETS _ASM_BYTES(0xf2,0x0f,0x01,0xca)
19 #define ERETU _ASM_BYTES(0xf3,0x0f,0x01,0xca)
20
21 /*
22 * RSP is aligned to a 64-byte boundary before used to push a new stack frame
23 */
24 #define FRED_STACK_FRAME_RSP_MASK _AT(unsigned long, (~0x3f))
25
26 /*
27 * Used for the return address for call emulation during code patching,
28 * and measured in 64-byte cache lines.
29 */
30 #define FRED_CONFIG_REDZONE_AMOUNT 1
31 #define FRED_CONFIG_REDZONE (_AT(unsigned long, FRED_CONFIG_REDZONE_AMOUNT) << 6)
32 #define FRED_CONFIG_INT_STKLVL(l) (_AT(unsigned long, l) << 9)
33 #define FRED_CONFIG_ENTRYPOINT(p) _AT(unsigned long, (p))
34
35 #ifndef __ASSEMBLY__
36
37 #ifdef CONFIG_X86_FRED
38 #include <linux/kernel.h>
39
40 #include <asm/ptrace.h>
41
42 struct fred_info {
43 /* Event data: CR2, DR6, ... */
44 unsigned long edata;
45 unsigned long resv;
46 };
47
48 /* Full format of the FRED stack frame */
49 struct fred_frame {
50 struct pt_regs regs;
51 struct fred_info info;
52 };
53
54 static __always_inline struct fred_info *fred_info(struct pt_regs *regs)
55 {
56 return &container_of(regs, struct fred_frame, regs)->info;
57 }
58
59 static __always_inline unsigned long fred_event_data(struct pt_regs *regs)
60 {
61 return fred_info(regs)->edata;
62 }
63
64 void asm_fred_entrypoint_user(void);
65 void asm_fred_entrypoint_kernel(void);
66 void asm_fred_entry_from_kvm(struct fred_ss);
67
68 __visible void fred_entry_from_user(struct pt_regs *regs);
69 __visible void fred_entry_from_kernel(struct pt_regs *regs);
70 __visible void __fred_entry_from_kvm(struct pt_regs *regs);
71
72 /* Can be called from noinstr code, thus __always_inline */
73 static __always_inline void fred_entry_from_kvm(unsigned int type, unsigned int vector)
74 {
75 struct fred_ss ss = {
76 .ss =__KERNEL_DS,
77 .type = type,
78 .vector = vector,
79 .nmi = type == EVENT_TYPE_NMI,
80 .lm = 1,
81 };
82
83 asm_fred_entry_from_kvm(ss);
84 }
85
86 void cpu_init_fred_exceptions(void);
87 void fred_complete_exception_setup(void);
88
89 #else /* CONFIG_X86_FRED */
90 static __always_inline unsigned long fred_event_data(struct pt_regs *regs) { return 0; }
91 static inline void cpu_init_fred_exceptions(void) { }
92 static inline void fred_complete_exception_setup(void) { }
93 static __always_inline void fred_entry_from_kvm(unsigned int type, unsigned int vector) { }
94 #endif /* CONFIG_X86_FRED */
95 #endif /* !__ASSEMBLY__ */
96
97 #endif /* ASM_X86_FRED_H */
98
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