5 #include <linux/stddef.h>
6 #include <linux/types.h>
7 #include <linux/cache.h>
9 /* Per processor datastructure. %gs points to it while the kernel runs */
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 long volatile *level4_pgt; /* Per CPU top level page table */
21 unsigned int __softirq_pending;
22 unsigned int __nmi_count; /* number of NMI on this CPUs */
23 struct mm_struct *active_mm;
25 unsigned apic_timer_irqs;
26 } ____cacheline_aligned;
29 #define IRQSTACK_ORDER 2
30 #define IRQSTACKSIZE (PAGE_SIZE << IRQSTACK_ORDER)
32 extern struct x8664_pda cpu_pda[];
35 * There is no fast way to get the base address of the PDA, all the accesses
36 * have to mention %fs/%gs. So it needs to be done this Torvaldian way.
38 #define sizeof_field(type,field) (sizeof(((type *)0)->field))
39 #define typeof_field(type,field) typeof(((type *)0)->field)
41 extern void __bad_pda_field(void);
43 #define pda_offset(field) offsetof(struct x8664_pda, field)
45 #define pda_to_op(op,field,val) do { \
46 switch (sizeof_field(struct x8664_pda, field)) { \
48 asm volatile(op "w %0,%%gs:%P1"::"r" (val),"i"(pda_offset(field)):"memory"); break; \
50 asm volatile(op "l %0,%%gs:%P1"::"r" (val),"i"(pda_offset(field)):"memory"); break; \
52 asm volatile(op "q %0,%%gs:%P1"::"r" (val),"i"(pda_offset(field)):"memory"); break; \
53 default: __bad_pda_field(); \
58 * AK: PDA read accesses should be neither volatile nor have an memory clobber.
59 * Unfortunately removing them causes all hell to break lose currently.
61 #define pda_from_op(op,field) ({ \
62 typedef typeof_field(struct x8664_pda, field) T__; T__ ret__; \
63 switch (sizeof_field(struct x8664_pda, field)) { \
65 asm volatile(op "w %%gs:%P1,%0":"=r" (ret__):"i"(pda_offset(field)):"memory"); break;\
67 asm volatile(op "l %%gs:%P1,%0":"=r" (ret__):"i"(pda_offset(field)):"memory"); break;\
69 asm volatile(op "q %%gs:%P1,%0":"=r" (ret__):"i"(pda_offset(field)):"memory"); break;\
70 default: __bad_pda_field(); \
75 #define read_pda(field) pda_from_op("mov",field)
76 #define write_pda(field,val) pda_to_op("mov",field,val)
77 #define add_pda(field,val) pda_to_op("add",field,val)
78 #define sub_pda(field,val) pda_to_op("sub",field,val)
82 #define PDA_STACKOFFSET (5*8)