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 int __softirq_pending;
21 unsigned int __nmi_count; /* number of NMI on this CPUs */
22 unsigned long idle_timestamp;
23 struct mm_struct *active_mm;
25 unsigned apic_timer_irqs;
26 int kernel_mode; /* kernel or user mode */
27 } ____cacheline_aligned;
30 #define IRQSTACK_ORDER 2
31 #define IRQSTACKSIZE (PAGE_SIZE << IRQSTACK_ORDER)
33 extern struct x8664_pda cpu_pda[];
36 * There is no fast way to get the base address of the PDA, all the accesses
37 * have to mention %fs/%gs. So it needs to be done this Torvaldian way.
39 #define sizeof_field(type,field) (sizeof(((type *)0)->field))
40 #define typeof_field(type,field) typeof(((type *)0)->field)
42 extern void __bad_pda_field(void);
44 #define pda_offset(field) offsetof(struct x8664_pda, field)
46 #define pda_to_op(op,field,val) do { \
47 switch (sizeof_field(struct x8664_pda, field)) { \
49 asm volatile(op "w %0,%%gs:%P1"::"r" (val),"i"(pda_offset(field)):"memory"); break; \
51 asm volatile(op "l %0,%%gs:%P1"::"r" (val),"i"(pda_offset(field)):"memory"); break; \
53 asm volatile(op "q %0,%%gs:%P1"::"r" (val),"i"(pda_offset(field)):"memory"); break; \
54 default: __bad_pda_field(); \
59 * AK: PDA read accesses should be neither volatile nor have an memory clobber.
60 * Unfortunately removing them causes all hell to break lose currently.
62 #define pda_from_op(op,field) ({ \
63 typedef typeof_field(struct x8664_pda, field) T__; T__ ret__; \
64 switch (sizeof_field(struct x8664_pda, field)) { \
66 asm volatile(op "w %%gs:%P1,%0":"=r" (ret__):"i"(pda_offset(field)):"memory"); break;\
68 asm volatile(op "l %%gs:%P1,%0":"=r" (ret__):"i"(pda_offset(field)):"memory"); break;\
70 asm volatile(op "q %%gs:%P1,%0":"=r" (ret__):"i"(pda_offset(field)):"memory"); break;\
71 default: __bad_pda_field(); \
76 #define read_pda(field) pda_from_op("mov",field)
77 #define write_pda(field,val) pda_to_op("mov",field,val)
78 #define add_pda(field,val) pda_to_op("add",field,val)
79 #define sub_pda(field,val) pda_to_op("sub",field,val)
83 #define PDA_STACKOFFSET (5*8)