80860afffbdbbede4092bb18a6946e5b0a2831f9
[linux-2.6.git] / include / asm-x86 / pda.h
1 #ifndef ASM_X86__PDA_H
2 #define ASM_X86__PDA_H
3
4 #ifndef __ASSEMBLY__
5 #include <linux/stddef.h>
6 #include <linux/types.h>
7 #include <linux/cache.h>
8 #include <asm/page.h>
9
10 /* Per processor datastructure. %gs points to it while the kernel runs */
11 struct x8664_pda {
12         struct task_struct *pcurrent;   /* 0  Current process */
13         unsigned long data_offset;      /* 8 Per cpu data offset from linker
14                                            address */
15         unsigned long kernelstack;      /* 16 top of kernel stack for current */
16         unsigned long oldrsp;           /* 24 user rsp for system call */
17         int irqcount;                   /* 32 Irq nesting counter. Starts -1 */
18         unsigned int cpunumber;         /* 36 Logical CPU number */
19 #ifdef CONFIG_CC_STACKPROTECTOR
20         unsigned long stack_canary;     /* 40 stack canary value */
21                                         /* gcc-ABI: this canary MUST be at
22                                            offset 40!!! */
23 #endif
24         char *irqstackptr;
25         short nodenumber;               /* number of current node (32k max) */
26         short in_bootmem;               /* pda lives in bootmem */
27         unsigned int __softirq_pending;
28         unsigned int __nmi_count;       /* number of NMI on this CPUs */
29         short mmu_state;
30         short isidle;
31         struct mm_struct *active_mm;
32         unsigned apic_timer_irqs;
33         unsigned irq0_irqs;
34         unsigned irq_resched_count;
35         unsigned irq_call_count;
36         unsigned irq_tlb_count;
37         unsigned irq_thermal_count;
38         unsigned irq_threshold_count;
39         unsigned irq_spurious_count;
40 } ____cacheline_aligned_in_smp;
41
42 extern struct x8664_pda **_cpu_pda;
43 extern void pda_init(int);
44
45 #define cpu_pda(i) (_cpu_pda[i])
46
47 /*
48  * There is no fast way to get the base address of the PDA, all the accesses
49  * have to mention %fs/%gs.  So it needs to be done this Torvaldian way.
50  */
51 extern void __bad_pda_field(void) __attribute__((noreturn));
52
53 /*
54  * proxy_pda doesn't actually exist, but tell gcc it is accessed for
55  * all PDA accesses so it gets read/write dependencies right.
56  */
57 extern struct x8664_pda _proxy_pda;
58
59 #define pda_offset(field) offsetof(struct x8664_pda, field)
60
61 #define pda_to_op(op, field, val)                                       \
62 do {                                                                    \
63         typedef typeof(_proxy_pda.field) T__;                           \
64         if (0) { T__ tmp__; tmp__ = (val); }    /* type checking */     \
65         switch (sizeof(_proxy_pda.field)) {                             \
66         case 2:                                                         \
67                 asm(op "w %1,%%gs:%c2" :                                \
68                     "+m" (_proxy_pda.field) :                           \
69                     "ri" ((T__)val),                                    \
70                     "i"(pda_offset(field)));                            \
71                 break;                                                  \
72         case 4:                                                         \
73                 asm(op "l %1,%%gs:%c2" :                                \
74                     "+m" (_proxy_pda.field) :                           \
75                     "ri" ((T__)val),                                    \
76                     "i" (pda_offset(field)));                           \
77                 break;                                                  \
78         case 8:                                                         \
79                 asm(op "q %1,%%gs:%c2":                                 \
80                     "+m" (_proxy_pda.field) :                           \
81                     "ri" ((T__)val),                                    \
82                     "i"(pda_offset(field)));                            \
83                 break;                                                  \
84         default:                                                        \
85                 __bad_pda_field();                                      \
86         }                                                               \
87 } while (0)
88
89 #define pda_from_op(op, field)                  \
90 ({                                              \
91         typeof(_proxy_pda.field) ret__;         \
92         switch (sizeof(_proxy_pda.field)) {     \
93         case 2:                                 \
94                 asm(op "w %%gs:%c1,%0" :        \
95                     "=r" (ret__) :              \
96                     "i" (pda_offset(field)),    \
97                     "m" (_proxy_pda.field));    \
98                 break;                          \
99         case 4:                                 \
100                 asm(op "l %%gs:%c1,%0":         \
101                     "=r" (ret__):               \
102                     "i" (pda_offset(field)),    \
103                     "m" (_proxy_pda.field));    \
104                 break;                          \
105         case 8:                                 \
106                 asm(op "q %%gs:%c1,%0":         \
107                     "=r" (ret__) :              \
108                     "i" (pda_offset(field)),    \
109                     "m" (_proxy_pda.field));    \
110                 break;                          \
111         default:                                \
112                 __bad_pda_field();              \
113         }                                       \
114         ret__;                                  \
115 })
116
117 #define read_pda(field)         pda_from_op("mov", field)
118 #define write_pda(field, val)   pda_to_op("mov", field, val)
119 #define add_pda(field, val)     pda_to_op("add", field, val)
120 #define sub_pda(field, val)     pda_to_op("sub", field, val)
121 #define or_pda(field, val)      pda_to_op("or", field, val)
122
123 /* This is not atomic against other CPUs -- CPU preemption needs to be off */
124 #define test_and_clear_bit_pda(bit, field)                              \
125 ({                                                                      \
126         int old__;                                                      \
127         asm volatile("btr %2,%%gs:%c3\n\tsbbl %0,%0"                    \
128                      : "=r" (old__), "+m" (_proxy_pda.field)            \
129                      : "dIr" (bit), "i" (pda_offset(field)) : "memory");\
130         old__;                                                          \
131 })
132
133 #endif
134
135 #define PDA_STACKOFFSET (5*8)
136
137 #endif /* ASM_X86__PDA_H */