]>
Commit | Line | Data |
---|---|---|
9ca36101 JF |
1 | /* |
2 | Per-processor Data Areas | |
3 | Jeremy Fitzhardinge <jeremy@goop.org> 2006 | |
4 | Based on asm-x86_64/pda.h by Andi Kleen. | |
5 | */ | |
6 | #ifndef _I386_PDA_H | |
7 | #define _I386_PDA_H | |
8 | ||
9 | #include <linux/stddef.h> | |
ec7fcaab | 10 | #include <linux/types.h> |
9ca36101 JF |
11 | |
12 | struct i386_pda | |
13 | { | |
14 | struct i386_pda *_pda; /* pointer to self */ | |
b2938f88 JF |
15 | |
16 | int cpu_number; | |
ec7fcaab | 17 | struct task_struct *pcurrent; /* current process */ |
70463dac | 18 | struct pt_regs *irq_regs; |
9ca36101 JF |
19 | }; |
20 | ||
21 | extern struct i386_pda *_cpu_pda[]; | |
22 | ||
23 | #define cpu_pda(i) (_cpu_pda[i]) | |
24 | ||
25 | #define pda_offset(field) offsetof(struct i386_pda, field) | |
26 | ||
27 | extern void __bad_pda_field(void); | |
28 | ||
29 | /* This variable is never instantiated. It is only used as a stand-in | |
30 | for the real per-cpu PDA memory, so that gcc can understand what | |
31 | memory operations the inline asms() below are performing. This | |
32 | eliminates the need to make the asms volatile or have memory | |
33 | clobbers, so gcc can readily analyse them. */ | |
34 | extern struct i386_pda _proxy_pda; | |
35 | ||
36 | #define pda_to_op(op,field,val) \ | |
37 | do { \ | |
38 | typedef typeof(_proxy_pda.field) T__; \ | |
39 | if (0) { T__ tmp__; tmp__ = (val); } \ | |
40 | switch (sizeof(_proxy_pda.field)) { \ | |
41 | case 1: \ | |
464d1a78 | 42 | asm(op "b %1,%%fs:%c2" \ |
9ca36101 JF |
43 | : "+m" (_proxy_pda.field) \ |
44 | :"ri" ((T__)val), \ | |
45 | "i"(pda_offset(field))); \ | |
46 | break; \ | |
47 | case 2: \ | |
464d1a78 | 48 | asm(op "w %1,%%fs:%c2" \ |
9ca36101 JF |
49 | : "+m" (_proxy_pda.field) \ |
50 | :"ri" ((T__)val), \ | |
51 | "i"(pda_offset(field))); \ | |
52 | break; \ | |
53 | case 4: \ | |
464d1a78 | 54 | asm(op "l %1,%%fs:%c2" \ |
9ca36101 JF |
55 | : "+m" (_proxy_pda.field) \ |
56 | :"ri" ((T__)val), \ | |
57 | "i"(pda_offset(field))); \ | |
58 | break; \ | |
59 | default: __bad_pda_field(); \ | |
60 | } \ | |
61 | } while (0) | |
62 | ||
63 | #define pda_from_op(op,field) \ | |
64 | ({ \ | |
65 | typeof(_proxy_pda.field) ret__; \ | |
66 | switch (sizeof(_proxy_pda.field)) { \ | |
67 | case 1: \ | |
464d1a78 | 68 | asm(op "b %%fs:%c1,%0" \ |
9ca36101 JF |
69 | : "=r" (ret__) \ |
70 | : "i" (pda_offset(field)), \ | |
71 | "m" (_proxy_pda.field)); \ | |
72 | break; \ | |
73 | case 2: \ | |
464d1a78 | 74 | asm(op "w %%fs:%c1,%0" \ |
9ca36101 JF |
75 | : "=r" (ret__) \ |
76 | : "i" (pda_offset(field)), \ | |
77 | "m" (_proxy_pda.field)); \ | |
78 | break; \ | |
79 | case 4: \ | |
464d1a78 | 80 | asm(op "l %%fs:%c1,%0" \ |
9ca36101 JF |
81 | : "=r" (ret__) \ |
82 | : "i" (pda_offset(field)), \ | |
83 | "m" (_proxy_pda.field)); \ | |
84 | break; \ | |
85 | default: __bad_pda_field(); \ | |
86 | } \ | |
87 | ret__; }) | |
88 | ||
89 | /* Return a pointer to a pda field */ | |
90 | #define pda_addr(field) \ | |
91 | ((typeof(_proxy_pda.field) *)((unsigned char *)read_pda(_pda) + \ | |
92 | pda_offset(field))) | |
93 | ||
94 | #define read_pda(field) pda_from_op("mov",field) | |
95 | #define write_pda(field,val) pda_to_op("mov",field,val) | |
96 | #define add_pda(field,val) pda_to_op("add",field,val) | |
97 | #define sub_pda(field,val) pda_to_op("sub",field,val) | |
98 | #define or_pda(field,val) pda_to_op("or",field,val) | |
99 | ||
100 | #endif /* _I386_PDA_H */ |