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1da177e4 LT |
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 | ||
9 | /* Per processor datastructure. %gs points to it while the kernel runs */ | |
10 | struct x8664_pda { | |
11 | struct task_struct *pcurrent; /* Current process */ | |
12 | unsigned long data_offset; /* Per cpu data offset from linker address */ | |
13 | struct x8664_pda *me; /* Pointer to itself */ | |
14 | unsigned long kernelstack; /* top of kernel stack for current */ | |
15 | unsigned long oldrsp; /* user rsp for system call */ | |
16 | unsigned long irqrsp; /* Old rsp for interrupts. */ | |
17 | int irqcount; /* Irq nesting counter. Starts with -1 */ | |
18 | int cpunumber; /* Logical CPU number */ | |
19 | char *irqstackptr; /* top of irqstack */ | |
20 | unsigned int __softirq_pending; | |
21 | unsigned int __nmi_count; /* number of NMI on this CPUs */ | |
22 | struct mm_struct *active_mm; | |
23 | int mmu_state; | |
24 | unsigned apic_timer_irqs; | |
25 | } ____cacheline_aligned; | |
26 | ||
27 | ||
28 | #define IRQSTACK_ORDER 2 | |
29 | #define IRQSTACKSIZE (PAGE_SIZE << IRQSTACK_ORDER) | |
30 | ||
31 | extern struct x8664_pda cpu_pda[]; | |
32 | ||
33 | /* | |
34 | * There is no fast way to get the base address of the PDA, all the accesses | |
35 | * have to mention %fs/%gs. So it needs to be done this Torvaldian way. | |
36 | */ | |
37 | #define sizeof_field(type,field) (sizeof(((type *)0)->field)) | |
38 | #define typeof_field(type,field) typeof(((type *)0)->field) | |
39 | ||
40 | extern void __bad_pda_field(void); | |
41 | ||
42 | #define pda_offset(field) offsetof(struct x8664_pda, field) | |
43 | ||
44 | #define pda_to_op(op,field,val) do { \ | |
45 | switch (sizeof_field(struct x8664_pda, field)) { \ | |
46 | case 2: \ | |
47 | asm volatile(op "w %0,%%gs:%P1"::"r" (val),"i"(pda_offset(field)):"memory"); break; \ | |
48 | case 4: \ | |
49 | asm volatile(op "l %0,%%gs:%P1"::"r" (val),"i"(pda_offset(field)):"memory"); break; \ | |
50 | case 8: \ | |
51 | asm volatile(op "q %0,%%gs:%P1"::"r" (val),"i"(pda_offset(field)):"memory"); break; \ | |
52 | default: __bad_pda_field(); \ | |
53 | } \ | |
54 | } while (0) | |
55 | ||
56 | /* | |
57 | * AK: PDA read accesses should be neither volatile nor have an memory clobber. | |
58 | * Unfortunately removing them causes all hell to break lose currently. | |
59 | */ | |
60 | #define pda_from_op(op,field) ({ \ | |
61 | typedef typeof_field(struct x8664_pda, field) T__; T__ ret__; \ | |
62 | switch (sizeof_field(struct x8664_pda, field)) { \ | |
63 | case 2: \ | |
64 | asm volatile(op "w %%gs:%P1,%0":"=r" (ret__):"i"(pda_offset(field)):"memory"); break;\ | |
65 | case 4: \ | |
66 | asm volatile(op "l %%gs:%P1,%0":"=r" (ret__):"i"(pda_offset(field)):"memory"); break;\ | |
67 | case 8: \ | |
68 | asm volatile(op "q %%gs:%P1,%0":"=r" (ret__):"i"(pda_offset(field)):"memory"); break;\ | |
69 | default: __bad_pda_field(); \ | |
70 | } \ | |
71 | ret__; }) | |
72 | ||
73 | ||
74 | #define read_pda(field) pda_from_op("mov",field) | |
75 | #define write_pda(field,val) pda_to_op("mov",field,val) | |
76 | #define add_pda(field,val) pda_to_op("add",field,val) | |
77 | #define sub_pda(field,val) pda_to_op("sub",field,val) | |
78 | ||
79 | #endif | |
80 | ||
81 | #define PDA_STACKOFFSET (5*8) | |
82 | ||
83 | #endif |