1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
|
#ifndef __ARCH_DESC_H
#define __ARCH_DESC_H
#include <asm/ldt.h>
#include <asm/segment.h>
#define CPU_16BIT_STACK_SIZE 1024
#ifndef __ASSEMBLY__
#include <linux/preempt.h>
#include <linux/smp.h>
#include <linux/percpu.h>
#include <asm/mmu.h>
extern struct desc_struct cpu_gdt_table[GDT_ENTRIES];
DECLARE_PER_CPU(struct desc_struct, cpu_gdt_table[GDT_ENTRIES]);
DECLARE_PER_CPU(unsigned char, cpu_16bit_stack[CPU_16BIT_STACK_SIZE]);
struct Xgt_desc_struct {
unsigned short size;
unsigned long address __attribute__((packed));
unsigned short pad;
} __attribute__ ((packed));
extern struct Xgt_desc_struct idt_descr, cpu_gdt_descr[NR_CPUS];
#define load_TR_desc() __asm__ __volatile__("ltr %%ax"::"a" (GDT_ENTRY_TSS*8))
#define load_LDT_desc() __asm__ __volatile__("lldt %%ax"::"a" (GDT_ENTRY_LDT*8))
/*
* This is the ldt that every process will get unless we need
* something other than this.
*/
extern struct desc_struct default_ldt[];
extern void set_intr_gate(unsigned int irq, void * addr);
#define _set_tssldt_desc(n,addr,limit,type) \
__asm__ __volatile__ ("movw %w3,0(%2)\n\t" \
"movw %%ax,2(%2)\n\t" \
"rorl $16,%%eax\n\t" \
"movb %%al,4(%2)\n\t" \
"movb %4,5(%2)\n\t" \
"movb $0,6(%2)\n\t" \
"movb %%ah,7(%2)\n\t" \
"rorl $16,%%eax" \
: "=m"(*(n)) : "a" (addr), "r"(n), "ir"(limit), "i"(type))
static inline void __set_tss_desc(unsigned int cpu, unsigned int entry, void *addr)
{
_set_tssldt_desc(&per_cpu(cpu_gdt_table, cpu)[entry], (int)addr,
offsetof(struct tss_struct, __cacheline_filler) - 1, 0x89);
}
#define set_tss_desc(cpu,addr) __set_tss_desc(cpu, GDT_ENTRY_TSS, addr)
static inline void set_ldt_desc(unsigned int cpu, void *addr, unsigned int size)
{
_set_tssldt_desc(&per_cpu(cpu_gdt_table, cpu)[GDT_ENTRY_LDT], (int)addr, ((size << 3)-1), 0x82);
}
#define LDT_entry_a(info) \
((((info)->base_addr & 0x0000ffff) << 16) | ((info)->limit & 0x0ffff))
#define LDT_entry_b(info) \
(((info)->base_addr & 0xff000000) | \
(((info)->base_addr & 0x00ff0000) >> 16) | \
((info)->limit & 0xf0000) | \
(((info)->read_exec_only ^ 1) << 9) | \
((info)->contents << 10) | \
(((info)->seg_not_present ^ 1) << 15) | \
((info)->seg_32bit << 22) | \
((info)->limit_in_pages << 23) | \
((info)->useable << 20) | \
0x7000)
#define LDT_empty(info) (\
(info)->base_addr == 0 && \
(info)->limit == 0 && \
(info)->contents == 0 && \
(info)->read_exec_only == 1 && \
(info)->seg_32bit == 0 && \
(info)->limit_in_pages == 0 && \
(info)->seg_not_present == 1 && \
(info)->useable == 0 )
#if TLS_SIZE != 24
# error update this code.
#endif
static inline void load_TLS(struct thread_struct *t, unsigned int cpu)
{
#define C(i) per_cpu(cpu_gdt_table, cpu)[GDT_ENTRY_TLS_MIN + i] = t->tls_array[i]
C(0); C(1); C(2);
#undef C
}
static inline void clear_LDT(void)
{
int cpu = get_cpu();
set_ldt_desc(cpu, &default_ldt[0], 5);
load_LDT_desc();
put_cpu();
}
/*
* load one particular LDT into the current CPU
*/
static inline void load_LDT_nolock(mm_context_t *pc, int cpu)
{
void *segments = pc->ldt;
int count = pc->size;
if (likely(!count)) {
segments = &default_ldt[0];
count = 5;
}
set_ldt_desc(cpu, segments, count);
load_LDT_desc();
}
static inline void load_LDT(mm_context_t *pc)
{
int cpu = get_cpu();
load_LDT_nolock(pc, cpu);
put_cpu();
}
static inline unsigned long get_desc_base(unsigned long *desc)
{
unsigned long base;
base = ((desc[0] >> 16) & 0x0000ffff) |
((desc[1] << 16) & 0x00ff0000) |
(desc[1] & 0xff000000);
return base;
}
#endif /* !__ASSEMBLY__ */
#endif
|
