1 /* Written 2000 by Andi Kleen */
5 #include <linux/threads.h>
10 #define __TSS_INDEX(n) ((n)*64)
11 #define __LDT_INDEX(n) ((n)*64)
13 extern __u8 gdt_table[];
14 extern __u8 gdt_end[];
26 unsigned ist : 3, zero0 : 5, type : 5, dpl : 2, p : 1;
30 } __attribute__((packed));
32 // 8 byte segment descriptor
36 unsigned base1 : 8, type : 4, s : 1, dpl : 2, p : 1;
37 unsigned limit : 4, avl : 1, l : 1, d : 1, g : 1, base2 : 8;
38 } __attribute__((packed));
40 // LDT or TSS descriptor in the GDT. 16 bytes.
44 unsigned base1 : 8, type : 5, dpl : 2, p : 1;
45 unsigned limit1 : 4, zero0 : 3, g : 1, base2 : 8;
48 } __attribute__((packed));
52 struct ldttss_desc tss;
53 struct ldttss_desc ldt;
54 } ____cacheline_aligned;
56 extern struct per_cpu_gdt gdt_cpu_table[];
58 #define PTR_LOW(x) ((unsigned long)(x) & 0xFFFF)
59 #define PTR_MIDDLE(x) (((unsigned long)(x) >> 16) & 0xFFFF)
60 #define PTR_HIGH(x) ((unsigned long)(x) >> 32)
69 unsigned long address;
70 } __attribute__((packed)) ;
72 #define __GDT_HEAD_SIZE 64
73 #define __CPU_DESC_INDEX(x,field) \
74 ((x) * sizeof(struct per_cpu_gdt) + offsetof(struct per_cpu_gdt, field) + __GDT_HEAD_SIZE)
76 #define load_TR(cpu) asm volatile("ltr %w0"::"r" (__CPU_DESC_INDEX(cpu, tss)));
77 #define __load_LDT(cpu) asm volatile("lldt %w0"::"r" (__CPU_DESC_INDEX(cpu, ldt)));
78 #define clear_LDT(n) asm volatile("lldt %w0"::"r" (0))
80 extern struct gate_struct idt_table[];
82 #define copy_16byte(dst,src) memcpy((dst), (src), 16)
84 static inline void _set_gate(void *adr, unsigned type, unsigned long func, unsigned dpl, unsigned ist)
87 s.offset_low = PTR_LOW(func);
88 s.segment = __KERNEL_CS;
95 s.offset_middle = PTR_MIDDLE(func);
96 s.offset_high = PTR_HIGH(func);
100 static inline void set_intr_gate(int nr, void *func)
102 _set_gate(&idt_table[nr], GATE_INTERRUPT, (unsigned long) func, 0, 0);
105 static inline void set_intr_gate_ist(int nr, void *func, unsigned ist)
107 _set_gate(&idt_table[nr], GATE_INTERRUPT, (unsigned long) func, 0, ist);
110 static inline void set_system_gate(int nr, void *func)
112 _set_gate(&idt_table[nr], GATE_INTERRUPT, (unsigned long) func, 3, 0);
115 static inline void set_tssldt_descriptor(struct ldttss_desc *dst, unsigned long ptr, unsigned type,
119 dst->limit0 = size & 0xFFFF;
120 dst->base0 = PTR_LOW(ptr);
121 dst->base1 = PTR_MIDDLE(ptr) & 0xFF;
124 dst->limit1 = (size >> 16) & 0xF;
125 dst->base2 = (PTR_MIDDLE(ptr) >> 8) & 0xFF;
126 dst->base3 = PTR_HIGH(ptr);
129 static inline void set_tss_desc(unsigned n, void *addr)
131 set_tssldt_descriptor((void *)&gdt_table + __CPU_DESC_INDEX(n,tss), (unsigned long)addr, DESC_TSS, IO_BITMAP_OFFSET + IO_BITMAP_BYTES + 7);
134 static inline void set_ldt_desc(unsigned n, void *addr, int size)
136 set_tssldt_descriptor((void *)&gdt_table + __CPU_DESC_INDEX(n,ldt), (unsigned long)addr, DESC_LDT, size * 8);
140 * load one particular LDT into the current CPU
142 static inline void load_LDT (struct mm_struct *mm)
144 int cpu = smp_processor_id();
145 void *segments = mm->context.segments;
152 set_ldt_desc(cpu, segments, LDT_ENTRIES);
156 #endif /* !__ASSEMBLY__ */