c0305bff0f19349316ef4d61efa85f4a5e38f7a2
[sfrench/cifs-2.6.git] / include / asm-x86 / pda.h
1 #ifndef X86_64_PDA_H
2 #define X86_64_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         unsigned int nodenumber;        /* number of current node */
26         unsigned int __softirq_pending;
27         unsigned int __nmi_count;       /* number of NMI on this CPUs */
28         short mmu_state;
29         short isidle;
30         struct mm_struct *active_mm;
31         unsigned apic_timer_irqs;
32         unsigned irq0_irqs;
33         unsigned irq_resched_count;
34         unsigned irq_call_count;
35         unsigned irq_tlb_count;
36         unsigned irq_thermal_count;
37         unsigned irq_threshold_count;
38         unsigned irq_spurious_count;
39 } ____cacheline_aligned_in_smp;
40
41 extern struct x8664_pda *_cpu_pda[];
42 extern struct x8664_pda boot_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) do {          \
62         typedef typeof(_proxy_pda.field) T__;   \
63         if (0) { T__ tmp__; tmp__ = (val); }    /* type checking */ \
64         switch (sizeof(_proxy_pda.field)) {     \
65         case 2:                                 \
66                 asm(op "w %1,%%gs:%c2" :        \
67                     "+m" (_proxy_pda.field) :   \
68                     "ri" ((T__)val),            \
69                     "i"(pda_offset(field)));    \
70                 break;                          \
71         case 4:                                 \
72                 asm(op "l %1,%%gs:%c2" :        \
73                     "+m" (_proxy_pda.field) :   \
74                     "ri" ((T__)val),            \
75                     "i" (pda_offset(field)));   \
76                 break;                          \
77         case 8:                                 \
78                 asm(op "q %1,%%gs:%c2":         \
79                     "+m" (_proxy_pda.field) :   \
80                     "ri" ((T__)val),            \
81                     "i"(pda_offset(field)));    \
82                 break;                          \
83         default:                                \
84                 __bad_pda_field();              \
85         }                                       \
86         } while (0)
87
88 #define pda_from_op(op,field) ({                \
89         typeof(_proxy_pda.field) ret__;         \
90         switch (sizeof(_proxy_pda.field)) {     \
91         case 2:                                 \
92                 asm(op "w %%gs:%c1,%0" :        \
93                     "=r" (ret__) :              \
94                     "i" (pda_offset(field)),    \
95                     "m" (_proxy_pda.field));    \
96                  break;                         \
97         case 4:                                 \
98                 asm(op "l %%gs:%c1,%0":         \
99                     "=r" (ret__):               \
100                     "i" (pda_offset(field)),    \
101                     "m" (_proxy_pda.field));    \
102                  break;                         \
103         case 8:                                 \
104                 asm(op "q %%gs:%c1,%0":         \
105                     "=r" (ret__) :              \
106                     "i" (pda_offset(field)),    \
107                     "m" (_proxy_pda.field));    \
108                  break;                         \
109         default:                                \
110                 __bad_pda_field();              \
111        }                                        \
112        ret__; })
113
114 #define read_pda(field)         pda_from_op("mov", field)
115 #define write_pda(field, val)   pda_to_op("mov", field, val)
116 #define add_pda(field, val)     pda_to_op("add", field, val)
117 #define sub_pda(field, val)     pda_to_op("sub", field, val)
118 #define or_pda(field, val)      pda_to_op("or", field, val)
119
120 /* This is not atomic against other CPUs -- CPU preemption needs to be off */
121 #define test_and_clear_bit_pda(bit, field) ({           \
122         int old__;                                              \
123         asm volatile("btr %2,%%gs:%c3\n\tsbbl %0,%0"            \
124             : "=r" (old__), "+m" (_proxy_pda.field)             \
125             : "dIr" (bit), "i" (pda_offset(field)) : "memory"); \
126         old__;                                                  \
127 })
128
129 #endif
130
131 #define PDA_STACKOFFSET (5*8)
132
133 #endif