5 #include <asm/segment.h>
9 #include <linux/preempt.h>
10 #include <linux/smp.h>
14 extern struct desc_struct cpu_gdt_table[NR_CPUS][GDT_ENTRIES];
16 struct Xgt_desc_struct {
18 unsigned long address __attribute__((packed));
20 } __attribute__ ((packed));
22 extern struct Xgt_desc_struct idt_descr, cpu_gdt_descr[NR_CPUS];
24 #define load_TR_desc() __asm__ __volatile__("ltr %%ax"::"a" (GDT_ENTRY_TSS*8))
25 #define load_LDT_desc() __asm__ __volatile__("lldt %%ax"::"a" (GDT_ENTRY_LDT*8))
28 * This is the ldt that every process will get unless we need
29 * something other than this.
31 extern struct desc_struct default_ldt[];
32 extern void set_intr_gate(unsigned int irq, void * addr);
34 #define _set_tssldt_desc(n,addr,limit,type) \
35 __asm__ __volatile__ ("movw %w3,0(%2)\n\t" \
36 "movw %%ax,2(%2)\n\t" \
37 "rorl $16,%%eax\n\t" \
38 "movb %%al,4(%2)\n\t" \
41 "movb %%ah,7(%2)\n\t" \
43 : "=m"(*(n)) : "a" (addr), "r"(n), "ir"(limit), "i"(type))
45 static inline void __set_tss_desc(unsigned int cpu, unsigned int entry, void *addr)
47 _set_tssldt_desc(&cpu_gdt_table[cpu][entry], (int)addr, 235, 0x89);
50 #define set_tss_desc(cpu,addr) __set_tss_desc(cpu, GDT_ENTRY_TSS, addr)
52 static inline void set_ldt_desc(unsigned int cpu, void *addr, unsigned int size)
54 _set_tssldt_desc(&cpu_gdt_table[cpu][GDT_ENTRY_LDT], (int)addr, ((size << 3)-1), 0x82);
57 #define LDT_entry_a(info) \
58 ((((info)->base_addr & 0x0000ffff) << 16) | ((info)->limit & 0x0ffff))
60 #define LDT_entry_b(info) \
61 (((info)->base_addr & 0xff000000) | \
62 (((info)->base_addr & 0x00ff0000) >> 16) | \
63 ((info)->limit & 0xf0000) | \
64 (((info)->read_exec_only ^ 1) << 9) | \
65 ((info)->contents << 10) | \
66 (((info)->seg_not_present ^ 1) << 15) | \
67 ((info)->seg_32bit << 22) | \
68 ((info)->limit_in_pages << 23) | \
69 ((info)->useable << 20) | \
72 #define LDT_empty(info) (\
73 (info)->base_addr == 0 && \
74 (info)->limit == 0 && \
75 (info)->contents == 0 && \
76 (info)->read_exec_only == 1 && \
77 (info)->seg_32bit == 0 && \
78 (info)->limit_in_pages == 0 && \
79 (info)->seg_not_present == 1 && \
80 (info)->useable == 0 )
83 # error update this code.
86 static inline void load_TLS(struct thread_struct *t, unsigned int cpu)
88 #define C(i) cpu_gdt_table[cpu][GDT_ENTRY_TLS_MIN + i] = t->tls_array[i]
93 static inline void clear_LDT(void)
97 set_ldt_desc(cpu, &default_ldt[0], 5);
103 * load one particular LDT into the current CPU
105 static inline void load_LDT_nolock(mm_context_t *pc, int cpu)
107 void *segments = pc->ldt;
108 int count = pc->size;
110 if (likely(!count)) {
111 segments = &default_ldt[0];
115 set_ldt_desc(cpu, segments, count);
119 static inline void load_LDT(mm_context_t *pc)
122 load_LDT_nolock(pc, cpu);
126 #endif /* !__ASSEMBLY__ */