aboutsummaryrefslogtreecommitdiffstats
path: root/include/asm-x86_64/desc.h
blob: ac991b5ca0fd501c0b294963031ca505016dbb9e (plain)
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
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
/* Written 2000 by Andi Kleen */ 
#ifndef __ARCH_DESC_H
#define __ARCH_DESC_H

#include <linux/threads.h>
#include <asm/ldt.h>

#ifndef __ASSEMBLY__

#include <linux/string.h>
#include <linux/smp.h>
#include <asm/desc_defs.h>

#include <asm/segment.h>
#include <asm/mmu.h>

extern struct desc_struct cpu_gdt_table[GDT_ENTRIES];

#define load_TR_desc() asm volatile("ltr %w0"::"r" (GDT_ENTRY_TSS*8))
#define load_LDT_desc() asm volatile("lldt %w0"::"r" (GDT_ENTRY_LDT*8))
#define clear_LDT()  asm volatile("lldt %w0"::"r" (0))

/*
 * This is the ldt that every process will get unless we need
 * something other than this.
 */
extern struct desc_struct default_ldt[];
extern struct gate_struct idt_table[]; 
extern struct desc_ptr cpu_gdt_descr[];

/* the cpu gdt accessor */
#define cpu_gdt(_cpu) ((struct desc_struct *)cpu_gdt_descr[_cpu].address)

static inline void _set_gate(void *adr, unsigned type, unsigned long func, unsigned dpl, unsigned ist)  
{
	struct gate_struct s; 	
	s.offset_low = PTR_LOW(func); 
	s.segment = __KERNEL_CS;
	s.ist = ist; 
	s.p = 1;
	s.dpl = dpl; 
	s.zero0 = 0;
	s.zero1 = 0; 
	s.type = type; 
	s.offset_middle = PTR_MIDDLE(func); 
	s.offset_high = PTR_HIGH(func); 
	/* does not need to be atomic because it is only done once at setup time */ 
	memcpy(adr, &s, 16); 
} 

static inline void set_intr_gate(int nr, void *func) 
{ 
	BUG_ON((unsigned)nr > 0xFF);
	_set_gate(&idt_table[nr], GATE_INTERRUPT, (unsigned long) func, 0, 0); 
} 

static inline void set_intr_gate_ist(int nr, void *func, unsigned ist) 
{ 
	BUG_ON((unsigned)nr > 0xFF);
	_set_gate(&idt_table[nr], GATE_INTERRUPT, (unsigned long) func, 0, ist); 
} 

static inline void set_system_gate(int nr, void *func) 
{ 
	BUG_ON((unsigned)nr > 0xFF);
	_set_gate(&idt_table[nr], GATE_INTERRUPT, (unsigned long) func, 3, 0); 
} 

static inline void set_system_gate_ist(int nr, void *func, unsigned ist)
{
	_set_gate(&idt_table[nr], GATE_INTERRUPT, (unsigned long) func, 3, ist);
}

static inline void set_tssldt_descriptor(void *ptr, unsigned long tss, unsigned type, 
					 unsigned size) 
{ 
	struct ldttss_desc d;
	memset(&d,0,sizeof(d)); 
	d.limit0 = size & 0xFFFF;
	d.base0 = PTR_LOW(tss); 
	d.base1 = PTR_MIDDLE(tss) & 0xFF; 
	d.type = type;
	d.p = 1; 
	d.limit1 = (size >> 16) & 0xF;
	d.base2 = (PTR_MIDDLE(tss) >> 8) & 0xFF; 
	d.base3 = PTR_HIGH(tss); 
	memcpy(ptr, &d, 16); 
}

static inline void set_tss_desc(unsigned cpu, void *addr)
{ 
	/*
	 * sizeof(unsigned long) coming from an extra "long" at the end
	 * of the iobitmap. See tss_struct definition in processor.h
	 *
	 * -1? seg base+limit should be pointing to the address of the
	 * last valid byte
	 */
	set_tssldt_descriptor(&cpu_gdt(cpu)[GDT_ENTRY_TSS],
		(unsigned long)addr, DESC_TSS,
		IO_BITMAP_OFFSET + IO_BITMAP_BYTES + sizeof(unsigned long) - 1);
} 

static inline void set_ldt_desc(unsigned cpu, void *addr, int size)
{ 
	set_tssldt_descriptor(&cpu_gdt(cpu)[GDT_ENTRY_LDT], (unsigned long)addr,
			      DESC_LDT, size * 8 - 1);
}

#define LDT_entry_a(info) \
	((((info)->base_addr & 0x0000ffff) << 16) | ((info)->limit & 0x0ffff))
/* Don't allow setting of the lm bit. It is useless anyways because 
   64bit system calls require __USER_CS. */ 
#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) | \
	/* ((info)->lm << 21) | */ \
	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	&& \
	(info)->lm		== 0)

static inline void load_TLS(struct thread_struct *t, unsigned int cpu)
{
	unsigned int i;
	u64 *gdt = (u64 *)(cpu_gdt(cpu) + GDT_ENTRY_TLS_MIN);

	for (i = 0; i < GDT_ENTRY_TLS_ENTRIES; i++)
		gdt[i] = t->tls_array[i];
} 

/*
 * load one particular LDT into the current CPU
 */
static inline void load_LDT_nolock (mm_context_t *pc, int cpu)
{
	int count = pc->size;

	if (likely(!count)) {
		clear_LDT();
		return;
	}
		
	set_ldt_desc(cpu, pc->ldt, count);
	load_LDT_desc();
}

static inline void load_LDT(mm_context_t *pc)
{
	int cpu = get_cpu();
	load_LDT_nolock(pc, cpu);
	put_cpu();
}

extern struct desc_ptr idt_descr;

#endif /* !__ASSEMBLY__ */

#endif