diff options
Diffstat (limited to 'include/asm-i386/pda.h')
| -rw-r--r-- | include/asm-i386/pda.h | 100 |
1 files changed, 100 insertions, 0 deletions
diff --git a/include/asm-i386/pda.h b/include/asm-i386/pda.h new file mode 100644 index 000000000000..2ba2736aa109 --- /dev/null +++ b/include/asm-i386/pda.h | |||
| @@ -0,0 +1,100 @@ | |||
| 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> | ||
| 10 | #include <linux/types.h> | ||
| 11 | |||
| 12 | struct i386_pda | ||
| 13 | { | ||
| 14 | struct i386_pda *_pda; /* pointer to self */ | ||
| 15 | |||
| 16 | int cpu_number; | ||
| 17 | struct task_struct *pcurrent; /* current process */ | ||
| 18 | struct pt_regs *irq_regs; | ||
| 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: \ | ||
| 42 | asm(op "b %1,%%gs:%c2" \ | ||
| 43 | : "+m" (_proxy_pda.field) \ | ||
| 44 | :"ri" ((T__)val), \ | ||
| 45 | "i"(pda_offset(field))); \ | ||
| 46 | break; \ | ||
| 47 | case 2: \ | ||
| 48 | asm(op "w %1,%%gs:%c2" \ | ||
| 49 | : "+m" (_proxy_pda.field) \ | ||
| 50 | :"ri" ((T__)val), \ | ||
| 51 | "i"(pda_offset(field))); \ | ||
| 52 | break; \ | ||
| 53 | case 4: \ | ||
| 54 | asm(op "l %1,%%gs:%c2" \ | ||
| 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: \ | ||
| 68 | asm(op "b %%gs:%c1,%0" \ | ||
| 69 | : "=r" (ret__) \ | ||
| 70 | : "i" (pda_offset(field)), \ | ||
| 71 | "m" (_proxy_pda.field)); \ | ||
| 72 | break; \ | ||
| 73 | case 2: \ | ||
| 74 | asm(op "w %%gs:%c1,%0" \ | ||
| 75 | : "=r" (ret__) \ | ||
| 76 | : "i" (pda_offset(field)), \ | ||
| 77 | "m" (_proxy_pda.field)); \ | ||
| 78 | break; \ | ||
| 79 | case 4: \ | ||
| 80 | asm(op "l %%gs:%c1,%0" \ | ||
| 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 */ | ||