x86/mm: Expand the exception table logic to allow new handling options
[firefly-linux-kernel-4.4.55.git] / arch / x86 / include / asm / asm.h
1 #ifndef _ASM_X86_ASM_H
2 #define _ASM_X86_ASM_H
3
4 #ifdef __ASSEMBLY__
5 # define __ASM_FORM(x)  x
6 # define __ASM_FORM_RAW(x)     x
7 # define __ASM_FORM_COMMA(x) x,
8 #else
9 # define __ASM_FORM(x)  " " #x " "
10 # define __ASM_FORM_RAW(x)     #x
11 # define __ASM_FORM_COMMA(x) " " #x ","
12 #endif
13
14 #ifdef CONFIG_X86_32
15 # define __ASM_SEL(a,b) __ASM_FORM(a)
16 # define __ASM_SEL_RAW(a,b) __ASM_FORM_RAW(a)
17 #else
18 # define __ASM_SEL(a,b) __ASM_FORM(b)
19 # define __ASM_SEL_RAW(a,b) __ASM_FORM_RAW(b)
20 #endif
21
22 #define __ASM_SIZE(inst, ...)   __ASM_SEL(inst##l##__VA_ARGS__, \
23                                           inst##q##__VA_ARGS__)
24 #define __ASM_REG(reg)         __ASM_SEL_RAW(e##reg, r##reg)
25
26 #define _ASM_PTR        __ASM_SEL(.long, .quad)
27 #define _ASM_ALIGN      __ASM_SEL(.balign 4, .balign 8)
28
29 #define _ASM_MOV        __ASM_SIZE(mov)
30 #define _ASM_INC        __ASM_SIZE(inc)
31 #define _ASM_DEC        __ASM_SIZE(dec)
32 #define _ASM_ADD        __ASM_SIZE(add)
33 #define _ASM_SUB        __ASM_SIZE(sub)
34 #define _ASM_XADD       __ASM_SIZE(xadd)
35
36 #define _ASM_AX         __ASM_REG(ax)
37 #define _ASM_BX         __ASM_REG(bx)
38 #define _ASM_CX         __ASM_REG(cx)
39 #define _ASM_DX         __ASM_REG(dx)
40 #define _ASM_SP         __ASM_REG(sp)
41 #define _ASM_BP         __ASM_REG(bp)
42 #define _ASM_SI         __ASM_REG(si)
43 #define _ASM_DI         __ASM_REG(di)
44
45 /* Exception table entry */
46 #ifdef __ASSEMBLY__
47 # define _ASM_EXTABLE_HANDLE(from, to, handler)                 \
48         .pushsection "__ex_table","a" ;                         \
49         .balign 4 ;                                             \
50         .long (from) - . ;                                      \
51         .long (to) - . ;                                        \
52         .long (handler) - . ;                                   \
53         .popsection
54
55 # define _ASM_EXTABLE(from, to)                                 \
56         _ASM_EXTABLE_HANDLE(from, to, ex_handler_default)
57
58 # define _ASM_EXTABLE_FAULT(from, to)                           \
59         _ASM_EXTABLE_HANDLE(from, to, ex_handler_fault)
60
61 # define _ASM_EXTABLE_EX(from, to)                              \
62         _ASM_EXTABLE_HANDLE(from, to, ex_handler_ext)
63
64 # define _ASM_NOKPROBE(entry)                                   \
65         .pushsection "_kprobe_blacklist","aw" ;                 \
66         _ASM_ALIGN ;                                            \
67         _ASM_PTR (entry);                                       \
68         .popsection
69
70 .macro ALIGN_DESTINATION
71         /* check for bad alignment of destination */
72         movl %edi,%ecx
73         andl $7,%ecx
74         jz 102f                         /* already aligned */
75         subl $8,%ecx
76         negl %ecx
77         subl %ecx,%edx
78 100:    movb (%rsi),%al
79 101:    movb %al,(%rdi)
80         incq %rsi
81         incq %rdi
82         decl %ecx
83         jnz 100b
84 102:
85         .section .fixup,"ax"
86 103:    addl %ecx,%edx                  /* ecx is zerorest also */
87         jmp copy_user_handle_tail
88         .previous
89
90         _ASM_EXTABLE(100b,103b)
91         _ASM_EXTABLE(101b,103b)
92         .endm
93
94 #else
95 # define _EXPAND_EXTABLE_HANDLE(x) #x
96 # define _ASM_EXTABLE_HANDLE(from, to, handler)                 \
97         " .pushsection \"__ex_table\",\"a\"\n"                  \
98         " .balign 4\n"                                          \
99         " .long (" #from ") - .\n"                              \
100         " .long (" #to ") - .\n"                                \
101         " .long (" _EXPAND_EXTABLE_HANDLE(handler) ") - .\n"    \
102         " .popsection\n"
103
104 # define _ASM_EXTABLE(from, to)                                 \
105         _ASM_EXTABLE_HANDLE(from, to, ex_handler_default)
106
107 # define _ASM_EXTABLE_FAULT(from, to)                           \
108         _ASM_EXTABLE_HANDLE(from, to, ex_handler_fault)
109
110 # define _ASM_EXTABLE_EX(from, to)                              \
111         _ASM_EXTABLE_HANDLE(from, to, ex_handler_ext)
112
113 /* For C file, we already have NOKPROBE_SYMBOL macro */
114 #endif
115
116 #endif /* _ASM_X86_ASM_H */