5 #include <linux/stddef.h>
6 #include <linux/types.h>
7 #include <linux/cache.h>
10 /* Per processor datastructure. %gs points to it while the kernel runs */
12 struct task_struct *pcurrent; /* 0 Current process */
13 unsigned long data_offset; /* 8 Per cpu data offset from linker
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 unsigned long stack_canary; /* 40 stack canary value */
20 /* gcc-ABI: this canary MUST be at
23 short nodenumber; /* number of current node (32k max) */
24 short in_bootmem; /* pda lives in bootmem */
25 unsigned int __softirq_pending;
26 unsigned int __nmi_count; /* number of NMI on this CPUs */
29 struct mm_struct *active_mm;
30 unsigned apic_timer_irqs;
32 unsigned irq_resched_count;
33 unsigned irq_call_count;
34 unsigned irq_tlb_count;
35 unsigned irq_thermal_count;
36 unsigned irq_threshold_count;
37 unsigned irq_spurious_count;
38 } ____cacheline_aligned_in_smp;
40 extern struct x8664_pda **_cpu_pda;
41 extern void pda_init(int);
43 #define cpu_pda(i) (_cpu_pda[i])
46 * There is no fast way to get the base address of the PDA, all the accesses
47 * have to mention %fs/%gs. So it needs to be done this Torvaldian way.
49 extern void __bad_pda_field(void) __attribute__((noreturn));
52 * proxy_pda doesn't actually exist, but tell gcc it is accessed for
53 * all PDA accesses so it gets read/write dependencies right.
55 extern struct x8664_pda _proxy_pda;
57 #define pda_offset(field) offsetof(struct x8664_pda, field)
59 #define pda_to_op(op, field, val) \
61 typedef typeof(_proxy_pda.field) T__; \
62 if (0) { T__ tmp__; tmp__ = (val); } /* type checking */ \
63 switch (sizeof(_proxy_pda.field)) { \
65 asm(op "w %1,%%gs:%c2" : \
66 "+m" (_proxy_pda.field) : \
68 "i"(pda_offset(field))); \
71 asm(op "l %1,%%gs:%c2" : \
72 "+m" (_proxy_pda.field) : \
74 "i" (pda_offset(field))); \
77 asm(op "q %1,%%gs:%c2": \
78 "+m" (_proxy_pda.field) : \
80 "i"(pda_offset(field))); \
87 #define pda_from_op(op, field) \
89 typeof(_proxy_pda.field) ret__; \
90 switch (sizeof(_proxy_pda.field)) { \
92 asm(op "w %%gs:%c1,%0" : \
94 "i" (pda_offset(field)), \
95 "m" (_proxy_pda.field)); \
98 asm(op "l %%gs:%c1,%0": \
100 "i" (pda_offset(field)), \
101 "m" (_proxy_pda.field)); \
104 asm(op "q %%gs:%c1,%0": \
106 "i" (pda_offset(field)), \
107 "m" (_proxy_pda.field)); \
115 #define read_pda(field) pda_from_op("mov", field)
116 #define write_pda(field, val) pda_to_op("mov", field, val)
117 #define add_pda(field, val) pda_to_op("add", field, val)
118 #define sub_pda(field, val) pda_to_op("sub", field, val)
119 #define or_pda(field, val) pda_to_op("or", field, val)
121 /* This is not atomic against other CPUs -- CPU preemption needs to be off */
122 #define test_and_clear_bit_pda(bit, field) \
125 asm volatile("btr %2,%%gs:%c3\n\tsbbl %0,%0" \
126 : "=r" (old__), "+m" (_proxy_pda.field) \
127 : "dIr" (bit), "i" (pda_offset(field)) : "memory");\
133 #define PDA_STACKOFFSET (5*8)
135 #define refresh_stack_canary() write_pda(stack_canary, current->stack_canary)
137 #endif /* _ASM_X86_PDA_H */