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1da177e4 LT |
1 | /* Written 2000 by Andi Kleen */ |
2 | #ifndef __ARCH_DESC_H | |
3 | #define __ARCH_DESC_H | |
4 | ||
5 | #include <linux/threads.h> | |
6 | #include <asm/ldt.h> | |
7 | ||
8 | #ifndef __ASSEMBLY__ | |
9 | ||
10 | #include <linux/string.h> | |
11 | #include <asm/segment.h> | |
12 | #include <asm/mmu.h> | |
13 | ||
14 | // 8 byte segment descriptor | |
15 | struct desc_struct { | |
16 | u16 limit0; | |
17 | u16 base0; | |
18 | unsigned base1 : 8, type : 4, s : 1, dpl : 2, p : 1; | |
19 | unsigned limit : 4, avl : 1, l : 1, d : 1, g : 1, base2 : 8; | |
20 | } __attribute__((packed)); | |
21 | ||
22 | struct n_desc_struct { | |
23 | unsigned int a,b; | |
24 | }; | |
25 | ||
26 | extern struct desc_struct cpu_gdt_table[NR_CPUS][GDT_ENTRIES]; | |
27 | ||
28 | enum { | |
29 | GATE_INTERRUPT = 0xE, | |
30 | GATE_TRAP = 0xF, | |
31 | GATE_CALL = 0xC, | |
32 | }; | |
33 | ||
34 | // 16byte gate | |
35 | struct gate_struct { | |
36 | u16 offset_low; | |
37 | u16 segment; | |
38 | unsigned ist : 3, zero0 : 5, type : 5, dpl : 2, p : 1; | |
39 | u16 offset_middle; | |
40 | u32 offset_high; | |
41 | u32 zero1; | |
42 | } __attribute__((packed)); | |
43 | ||
44 | #define PTR_LOW(x) ((unsigned long)(x) & 0xFFFF) | |
45 | #define PTR_MIDDLE(x) (((unsigned long)(x) >> 16) & 0xFFFF) | |
46 | #define PTR_HIGH(x) ((unsigned long)(x) >> 32) | |
47 | ||
48 | enum { | |
49 | DESC_TSS = 0x9, | |
50 | DESC_LDT = 0x2, | |
51 | }; | |
52 | ||
53 | // LDT or TSS descriptor in the GDT. 16 bytes. | |
54 | struct ldttss_desc { | |
55 | u16 limit0; | |
56 | u16 base0; | |
57 | unsigned base1 : 8, type : 5, dpl : 2, p : 1; | |
58 | unsigned limit1 : 4, zero0 : 3, g : 1, base2 : 8; | |
59 | u32 base3; | |
60 | u32 zero1; | |
61 | } __attribute__((packed)); | |
62 | ||
63 | struct desc_ptr { | |
64 | unsigned short size; | |
65 | unsigned long address; | |
66 | } __attribute__((packed)) ; | |
67 | ||
68 | #define load_TR_desc() asm volatile("ltr %w0"::"r" (GDT_ENTRY_TSS*8)) | |
69 | #define load_LDT_desc() asm volatile("lldt %w0"::"r" (GDT_ENTRY_LDT*8)) | |
70 | #define clear_LDT() asm volatile("lldt %w0"::"r" (0)) | |
71 | ||
72 | /* | |
73 | * This is the ldt that every process will get unless we need | |
74 | * something other than this. | |
75 | */ | |
76 | extern struct desc_struct default_ldt[]; | |
77 | extern struct gate_struct idt_table[]; | |
a940199f | 78 | extern struct desc_ptr cpu_gdt_descr[]; |
1da177e4 LT |
79 | |
80 | static inline void _set_gate(void *adr, unsigned type, unsigned long func, unsigned dpl, unsigned ist) | |
81 | { | |
82 | struct gate_struct s; | |
83 | s.offset_low = PTR_LOW(func); | |
84 | s.segment = __KERNEL_CS; | |
85 | s.ist = ist; | |
86 | s.p = 1; | |
87 | s.dpl = dpl; | |
88 | s.zero0 = 0; | |
89 | s.zero1 = 0; | |
90 | s.type = type; | |
91 | s.offset_middle = PTR_MIDDLE(func); | |
92 | s.offset_high = PTR_HIGH(func); | |
93 | /* does not need to be atomic because it is only done once at setup time */ | |
94 | memcpy(adr, &s, 16); | |
95 | } | |
96 | ||
97 | static inline void set_intr_gate(int nr, void *func) | |
98 | { | |
99 | _set_gate(&idt_table[nr], GATE_INTERRUPT, (unsigned long) func, 0, 0); | |
100 | } | |
101 | ||
102 | static inline void set_intr_gate_ist(int nr, void *func, unsigned ist) | |
103 | { | |
104 | _set_gate(&idt_table[nr], GATE_INTERRUPT, (unsigned long) func, 0, ist); | |
105 | } | |
106 | ||
107 | static inline void set_system_gate(int nr, void *func) | |
108 | { | |
109 | _set_gate(&idt_table[nr], GATE_INTERRUPT, (unsigned long) func, 3, 0); | |
110 | } | |
111 | ||
112 | static inline void set_tssldt_descriptor(void *ptr, unsigned long tss, unsigned type, | |
113 | unsigned size) | |
114 | { | |
115 | struct ldttss_desc d; | |
116 | memset(&d,0,sizeof(d)); | |
117 | d.limit0 = size & 0xFFFF; | |
118 | d.base0 = PTR_LOW(tss); | |
119 | d.base1 = PTR_MIDDLE(tss) & 0xFF; | |
120 | d.type = type; | |
121 | d.p = 1; | |
122 | d.limit1 = (size >> 16) & 0xF; | |
123 | d.base2 = (PTR_MIDDLE(tss) >> 8) & 0xFF; | |
124 | d.base3 = PTR_HIGH(tss); | |
125 | memcpy(ptr, &d, 16); | |
126 | } | |
127 | ||
128 | static inline void set_tss_desc(unsigned cpu, void *addr) | |
129 | { | |
130 | set_tssldt_descriptor(&cpu_gdt_table[cpu][GDT_ENTRY_TSS], (unsigned long)addr, | |
131 | DESC_TSS, | |
132 | sizeof(struct tss_struct) - 1); | |
133 | } | |
134 | ||
135 | static inline void set_ldt_desc(unsigned cpu, void *addr, int size) | |
136 | { | |
137 | set_tssldt_descriptor(&cpu_gdt_table[cpu][GDT_ENTRY_LDT], (unsigned long)addr, | |
138 | DESC_LDT, size * 8 - 1); | |
139 | } | |
140 | ||
141 | static inline void set_seg_base(unsigned cpu, int entry, void *base) | |
142 | { | |
143 | struct desc_struct *d = &cpu_gdt_table[cpu][entry]; | |
144 | u32 addr = (u32)(u64)base; | |
145 | BUG_ON((u64)base >> 32); | |
146 | d->base0 = addr & 0xffff; | |
147 | d->base1 = (addr >> 16) & 0xff; | |
148 | d->base2 = (addr >> 24) & 0xff; | |
149 | } | |
150 | ||
151 | #define LDT_entry_a(info) \ | |
152 | ((((info)->base_addr & 0x0000ffff) << 16) | ((info)->limit & 0x0ffff)) | |
153 | /* Don't allow setting of the lm bit. It is useless anyways because | |
154 | 64bit system calls require __USER_CS. */ | |
155 | #define LDT_entry_b(info) \ | |
156 | (((info)->base_addr & 0xff000000) | \ | |
157 | (((info)->base_addr & 0x00ff0000) >> 16) | \ | |
158 | ((info)->limit & 0xf0000) | \ | |
159 | (((info)->read_exec_only ^ 1) << 9) | \ | |
160 | ((info)->contents << 10) | \ | |
161 | (((info)->seg_not_present ^ 1) << 15) | \ | |
162 | ((info)->seg_32bit << 22) | \ | |
163 | ((info)->limit_in_pages << 23) | \ | |
164 | ((info)->useable << 20) | \ | |
165 | /* ((info)->lm << 21) | */ \ | |
166 | 0x7000) | |
167 | ||
168 | #define LDT_empty(info) (\ | |
169 | (info)->base_addr == 0 && \ | |
170 | (info)->limit == 0 && \ | |
171 | (info)->contents == 0 && \ | |
172 | (info)->read_exec_only == 1 && \ | |
173 | (info)->seg_32bit == 0 && \ | |
174 | (info)->limit_in_pages == 0 && \ | |
175 | (info)->seg_not_present == 1 && \ | |
176 | (info)->useable == 0 && \ | |
177 | (info)->lm == 0) | |
178 | ||
179 | #if TLS_SIZE != 24 | |
180 | # error update this code. | |
181 | #endif | |
182 | ||
183 | static inline void load_TLS(struct thread_struct *t, unsigned int cpu) | |
184 | { | |
185 | u64 *gdt = (u64 *)(cpu_gdt_table[cpu] + GDT_ENTRY_TLS_MIN); | |
186 | gdt[0] = t->tls_array[0]; | |
187 | gdt[1] = t->tls_array[1]; | |
188 | gdt[2] = t->tls_array[2]; | |
189 | } | |
190 | ||
191 | /* | |
192 | * load one particular LDT into the current CPU | |
193 | */ | |
194 | extern inline void load_LDT_nolock (mm_context_t *pc, int cpu) | |
195 | { | |
196 | int count = pc->size; | |
197 | ||
198 | if (likely(!count)) { | |
199 | clear_LDT(); | |
200 | return; | |
201 | } | |
202 | ||
203 | set_ldt_desc(cpu, pc->ldt, count); | |
204 | load_LDT_desc(); | |
205 | } | |
206 | ||
207 | static inline void load_LDT(mm_context_t *pc) | |
208 | { | |
209 | int cpu = get_cpu(); | |
210 | load_LDT_nolock(pc, cpu); | |
211 | put_cpu(); | |
212 | } | |
213 | ||
214 | extern struct desc_ptr idt_descr; | |
215 | ||
216 | #endif /* !__ASSEMBLY__ */ | |
217 | ||
218 | #endif |