xref: /openbmc/linux/arch/x86/include/asm/debugreg.h (revision 0c874100)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _ASM_X86_DEBUGREG_H
3 #define _ASM_X86_DEBUGREG_H
4 
5 
6 #include <linux/bug.h>
7 #include <uapi/asm/debugreg.h>
8 
9 DECLARE_PER_CPU(unsigned long, cpu_dr7);
10 
11 #ifndef CONFIG_PARAVIRT_XXL
12 /*
13  * These special macros can be used to get or set a debugging register
14  */
15 #define get_debugreg(var, register)				\
16 	(var) = native_get_debugreg(register)
17 #define set_debugreg(value, register)				\
18 	native_set_debugreg(register, value)
19 #endif
20 
21 static inline unsigned long native_get_debugreg(int regno)
22 {
23 	unsigned long val = 0;	/* Damn you, gcc! */
24 
25 	switch (regno) {
26 	case 0:
27 		asm("mov %%db0, %0" :"=r" (val));
28 		break;
29 	case 1:
30 		asm("mov %%db1, %0" :"=r" (val));
31 		break;
32 	case 2:
33 		asm("mov %%db2, %0" :"=r" (val));
34 		break;
35 	case 3:
36 		asm("mov %%db3, %0" :"=r" (val));
37 		break;
38 	case 6:
39 		asm("mov %%db6, %0" :"=r" (val));
40 		break;
41 	case 7:
42 		asm("mov %%db7, %0" :"=r" (val));
43 		break;
44 	default:
45 		BUG();
46 	}
47 	return val;
48 }
49 
50 static inline void native_set_debugreg(int regno, unsigned long value)
51 {
52 	switch (regno) {
53 	case 0:
54 		asm("mov %0, %%db0"	::"r" (value));
55 		break;
56 	case 1:
57 		asm("mov %0, %%db1"	::"r" (value));
58 		break;
59 	case 2:
60 		asm("mov %0, %%db2"	::"r" (value));
61 		break;
62 	case 3:
63 		asm("mov %0, %%db3"	::"r" (value));
64 		break;
65 	case 6:
66 		asm("mov %0, %%db6"	::"r" (value));
67 		break;
68 	case 7:
69 		asm("mov %0, %%db7"	::"r" (value));
70 		break;
71 	default:
72 		BUG();
73 	}
74 }
75 
76 static inline void hw_breakpoint_disable(void)
77 {
78 	/* Zero the control register for HW Breakpoint */
79 	set_debugreg(0UL, 7);
80 
81 	/* Zero-out the individual HW breakpoint address registers */
82 	set_debugreg(0UL, 0);
83 	set_debugreg(0UL, 1);
84 	set_debugreg(0UL, 2);
85 	set_debugreg(0UL, 3);
86 }
87 
88 static inline int hw_breakpoint_active(void)
89 {
90 	return __this_cpu_read(cpu_dr7) & DR_GLOBAL_ENABLE_MASK;
91 }
92 
93 extern void aout_dump_debugregs(struct user *dump);
94 
95 extern void hw_breakpoint_restore(void);
96 
97 #ifdef CONFIG_X86_64
98 DECLARE_PER_CPU(int, debug_stack_usage);
99 static inline void debug_stack_usage_inc(void)
100 {
101 	__this_cpu_inc(debug_stack_usage);
102 }
103 static inline void debug_stack_usage_dec(void)
104 {
105 	__this_cpu_dec(debug_stack_usage);
106 }
107 int is_debug_stack(unsigned long addr);
108 void debug_stack_set_zero(void);
109 void debug_stack_reset(void);
110 #else /* !X86_64 */
111 static inline int is_debug_stack(unsigned long addr) { return 0; }
112 static inline void debug_stack_set_zero(void) { }
113 static inline void debug_stack_reset(void) { }
114 static inline void debug_stack_usage_inc(void) { }
115 static inline void debug_stack_usage_dec(void) { }
116 #endif /* X86_64 */
117 
118 #ifdef CONFIG_CPU_SUP_AMD
119 extern void set_dr_addr_mask(unsigned long mask, int dr);
120 #else
121 static inline void set_dr_addr_mask(unsigned long mask, int dr) { }
122 #endif
123 
124 #endif /* _ASM_X86_DEBUGREG_H */
125