aboutsummaryrefslogtreecommitdiffstats
path: root/include/asm-i386/desc.h
diff options
context:
space:
mode:
Diffstat (limited to 'include/asm-i386/desc.h')
-rw-r--r--include/asm-i386/desc.h144
1 files changed, 144 insertions, 0 deletions
diff --git a/include/asm-i386/desc.h b/include/asm-i386/desc.h
new file mode 100644
index 000000000000..11e67811a990
--- /dev/null
+++ b/include/asm-i386/desc.h
@@ -0,0 +1,144 @@
1#ifndef __ARCH_DESC_H
2#define __ARCH_DESC_H
3
4#include <asm/ldt.h>
5#include <asm/segment.h>
6
7#define CPU_16BIT_STACK_SIZE 1024
8
9#ifndef __ASSEMBLY__
10
11#include <linux/preempt.h>
12#include <linux/smp.h>
13#include <linux/percpu.h>
14
15#include <asm/mmu.h>
16
17extern struct desc_struct cpu_gdt_table[GDT_ENTRIES];
18DECLARE_PER_CPU(struct desc_struct, cpu_gdt_table[GDT_ENTRIES]);
19
20DECLARE_PER_CPU(unsigned char, cpu_16bit_stack[CPU_16BIT_STACK_SIZE]);
21
22struct Xgt_desc_struct {
23 unsigned short size;
24 unsigned long address __attribute__((packed));
25 unsigned short pad;
26} __attribute__ ((packed));
27
28extern struct Xgt_desc_struct idt_descr, cpu_gdt_descr[NR_CPUS];
29
30#define load_TR_desc() __asm__ __volatile__("ltr %%ax"::"a" (GDT_ENTRY_TSS*8))
31#define load_LDT_desc() __asm__ __volatile__("lldt %%ax"::"a" (GDT_ENTRY_LDT*8))
32
33/*
34 * This is the ldt that every process will get unless we need
35 * something other than this.
36 */
37extern struct desc_struct default_ldt[];
38extern void set_intr_gate(unsigned int irq, void * addr);
39
40#define _set_tssldt_desc(n,addr,limit,type) \
41__asm__ __volatile__ ("movw %w3,0(%2)\n\t" \
42 "movw %%ax,2(%2)\n\t" \
43 "rorl $16,%%eax\n\t" \
44 "movb %%al,4(%2)\n\t" \
45 "movb %4,5(%2)\n\t" \
46 "movb $0,6(%2)\n\t" \
47 "movb %%ah,7(%2)\n\t" \
48 "rorl $16,%%eax" \
49 : "=m"(*(n)) : "a" (addr), "r"(n), "ir"(limit), "i"(type))
50
51static inline void __set_tss_desc(unsigned int cpu, unsigned int entry, void *addr)
52{
53 _set_tssldt_desc(&per_cpu(cpu_gdt_table, cpu)[entry], (int)addr,
54 offsetof(struct tss_struct, __cacheline_filler) - 1, 0x89);
55}
56
57#define set_tss_desc(cpu,addr) __set_tss_desc(cpu, GDT_ENTRY_TSS, addr)
58
59static inline void set_ldt_desc(unsigned int cpu, void *addr, unsigned int size)
60{
61 _set_tssldt_desc(&per_cpu(cpu_gdt_table, cpu)[GDT_ENTRY_LDT], (int)addr, ((size << 3)-1), 0x82);
62}
63
64#define LDT_entry_a(info) \
65 ((((info)->base_addr & 0x0000ffff) << 16) | ((info)->limit & 0x0ffff))
66
67#define LDT_entry_b(info) \
68 (((info)->base_addr & 0xff000000) | \
69 (((info)->base_addr & 0x00ff0000) >> 16) | \
70 ((info)->limit & 0xf0000) | \
71 (((info)->read_exec_only ^ 1) << 9) | \
72 ((info)->contents << 10) | \
73 (((info)->seg_not_present ^ 1) << 15) | \
74 ((info)->seg_32bit << 22) | \
75 ((info)->limit_in_pages << 23) | \
76 ((info)->useable << 20) | \
77 0x7000)
78
79#define LDT_empty(info) (\
80 (info)->base_addr == 0 && \
81 (info)->limit == 0 && \
82 (info)->contents == 0 && \
83 (info)->read_exec_only == 1 && \
84 (info)->seg_32bit == 0 && \
85 (info)->limit_in_pages == 0 && \
86 (info)->seg_not_present == 1 && \
87 (info)->useable == 0 )
88
89#if TLS_SIZE != 24
90# error update this code.
91#endif
92
93static inline void load_TLS(struct thread_struct *t, unsigned int cpu)
94{
95#define C(i) per_cpu(cpu_gdt_table, cpu)[GDT_ENTRY_TLS_MIN + i] = t->tls_array[i]
96 C(0); C(1); C(2);
97#undef C
98}
99
100static inline void clear_LDT(void)
101{
102 int cpu = get_cpu();
103
104 set_ldt_desc(cpu, &default_ldt[0], 5);
105 load_LDT_desc();
106 put_cpu();
107}
108
109/*
110 * load one particular LDT into the current CPU
111 */
112static inline void load_LDT_nolock(mm_context_t *pc, int cpu)
113{
114 void *segments = pc->ldt;
115 int count = pc->size;
116
117 if (likely(!count)) {
118 segments = &default_ldt[0];
119 count = 5;
120 }
121
122 set_ldt_desc(cpu, segments, count);
123 load_LDT_desc();
124}
125
126static inline void load_LDT(mm_context_t *pc)
127{
128 int cpu = get_cpu();
129 load_LDT_nolock(pc, cpu);
130 put_cpu();
131}
132
133static inline unsigned long get_desc_base(unsigned long *desc)
134{
135 unsigned long base;
136 base = ((desc[0] >> 16) & 0x0000ffff) |
137 ((desc[1] << 16) & 0x00ff0000) |
138 (desc[1] & 0xff000000);
139 return base;
140}
141
142#endif /* !__ASSEMBLY__ */
143
144#endif