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Glauber de Oliveira Costa80fbb692008-01-30 13:31:13 +01001#ifndef _ASM_DESC_H_
2#define _ASM_DESC_H_
3
4#ifndef __ASSEMBLY__
5#include <asm/desc_defs.h>
6#include <asm/ldt.h>
Glauber de Oliveira Costa881c2972008-01-30 13:31:14 +01007#include <asm/mmu.h>
Glauber de Oliveira Costa54cd0ea2008-01-30 13:31:14 +01008#include <linux/smp.h>
Glauber de Oliveira Costa80fbb692008-01-30 13:31:13 +01009
10static inline void fill_ldt(struct desc_struct *desc, struct user_desc *info)
11{
12 desc->limit0 = info->limit & 0x0ffff;
13 desc->base0 = info->base_addr & 0x0000ffff;
14
15 desc->base1 = (info->base_addr & 0x00ff0000) >> 16;
16 desc->type = (info->read_exec_only ^ 1) << 1;
17 desc->type |= info->contents << 2;
18 desc->s = 1;
19 desc->dpl = 0x3;
20 desc->p = info->seg_not_present ^ 1;
21 desc->limit = (info->limit & 0xf0000) >> 16;
22 desc->avl = info->useable;
23 desc->d = info->seg_32bit;
24 desc->g = info->limit_in_pages;
25 desc->base2 = (info->base_addr & 0xff000000) >> 24;
26}
27
Glauber de Oliveira Costa881c2972008-01-30 13:31:14 +010028extern struct desc_ptr idt_descr;
29extern gate_desc idt_table[];
Glauber de Oliveira Costa80fbb692008-01-30 13:31:13 +010030
Glauber de Oliveira Costa54cd0ea2008-01-30 13:31:14 +010031#ifdef CONFIG_X86_64
32extern struct desc_struct cpu_gdt_table[GDT_ENTRIES];
33extern struct desc_ptr cpu_gdt_descr[];
34/* the cpu gdt accessor */
35#define get_cpu_gdt_table(x) ((struct desc_struct *)cpu_gdt_descr[x].address)
36#else
37struct gdt_page {
38 struct desc_struct gdt[GDT_ENTRIES];
39} __attribute__((aligned(PAGE_SIZE)));
40DECLARE_PER_CPU(struct gdt_page, gdt_page);
41
42static inline struct desc_struct *get_cpu_gdt_table(unsigned int cpu)
43{
44 return per_cpu(gdt_page, cpu).gdt;
45}
46#endif
47
48#ifdef CONFIG_PARAVIRT
49#include <asm/paravirt.h>
50#else
51#define load_TR_desc() native_load_tr_desc()
52#define load_gdt(dtr) native_load_gdt(dtr)
53#define load_idt(dtr) native_load_idt(dtr)
54#define load_tr(tr) __asm__ __volatile("ltr %0"::"m" (tr))
55#define load_ldt(ldt) __asm__ __volatile("lldt %0"::"m" (ldt))
56
57#define store_gdt(dtr) native_store_gdt(dtr)
58#define store_idt(dtr) native_store_idt(dtr)
59#define store_tr(tr) (tr = native_store_tr())
60#define store_ldt(ldt) __asm__ ("sldt %0":"=m" (ldt))
61
62#define load_TLS(t, cpu) native_load_tls(t, cpu)
63#define set_ldt native_set_ldt
64
65#define write_ldt_entry(dt, entry, desc) \
66 native_write_ldt_entry(dt, entry, desc)
67#define write_gdt_entry(dt, entry, desc, type) \
68 native_write_gdt_entry(dt, entry, desc, type)
69#define write_idt_entry(dt, entry, g) native_write_idt_entry(dt, entry, g)
70#endif
71
72static inline void native_write_idt_entry(gate_desc *idt, int entry,
73 const gate_desc *gate)
74{
75 memcpy(&idt[entry], gate, sizeof(*gate));
76}
77
78static inline void native_write_ldt_entry(struct desc_struct *ldt, int entry,
79 const void *desc)
80{
81 memcpy(&ldt[entry], desc, 8);
82}
83
84static inline void native_write_gdt_entry(struct desc_struct *gdt, int entry,
85 const void *desc, int type)
86{
87 unsigned int size;
88 switch (type) {
89 case DESC_TSS:
90 size = sizeof(tss_desc);
91 break;
92 case DESC_LDT:
93 size = sizeof(ldt_desc);
94 break;
95 default:
96 size = sizeof(struct desc_struct);
97 break;
98 }
99 memcpy(&gdt[entry], desc, size);
100}
101
102static inline void set_tssldt_descriptor(struct ldttss_desc64 *d,
103 unsigned long tss, unsigned type,
104 unsigned size)
105{
106 memset(d, 0, sizeof(*d));
107 d->limit0 = size & 0xFFFF;
108 d->base0 = PTR_LOW(tss);
109 d->base1 = PTR_MIDDLE(tss) & 0xFF;
110 d->type = type;
111 d->p = 1;
112 d->limit1 = (size >> 16) & 0xF;
113 d->base2 = (PTR_MIDDLE(tss) >> 8) & 0xFF;
114 d->base3 = PTR_HIGH(tss);
115}
116
117static inline void pack_descriptor(struct desc_struct *desc, unsigned long base,
118 unsigned long limit, unsigned char type,
119 unsigned char flags)
120{
121 desc->a = ((base & 0xffff) << 16) | (limit & 0xffff);
122 desc->b = (base & 0xff000000) | ((base & 0xff0000) >> 16) |
123 (limit & 0x000f0000) | ((type & 0xff) << 8) |
124 ((flags & 0xf) << 20);
125 desc->p = 1;
126}
127
128static inline void pack_ldt(ldt_desc *ldt, unsigned long addr,
129 unsigned size)
130{
131
132#ifdef CONFIG_X86_64
133 set_tssldt_descriptor(ldt,
134 addr, DESC_LDT, size);
135#else
136 pack_descriptor(ldt, (unsigned long)addr,
137 size,
138 0x80 | DESC_LDT, 0);
139#endif
140}
141
142static inline void native_set_ldt(const void *addr, unsigned int entries)
143{
144 if (likely(entries == 0))
145 __asm__ __volatile__("lldt %w0"::"q" (0));
146 else {
147 unsigned cpu = smp_processor_id();
148 ldt_desc ldt;
149
150 pack_ldt(&ldt, (unsigned long)addr,
151 entries * sizeof(ldt) - 1);
152 write_gdt_entry(get_cpu_gdt_table(cpu), GDT_ENTRY_LDT,
153 &ldt, DESC_LDT);
154 __asm__ __volatile__("lldt %w0"::"q" (GDT_ENTRY_LDT*8));
155 }
156}
157
158static inline void native_load_tr_desc(void)
159{
160 asm volatile("ltr %w0"::"q" (GDT_ENTRY_TSS*8));
161}
162
163static inline void native_load_gdt(const struct desc_ptr *dtr)
164{
165 asm volatile("lgdt %0"::"m" (*dtr));
166}
167
168static inline void native_load_idt(const struct desc_ptr *dtr)
169{
170 asm volatile("lidt %0"::"m" (*dtr));
171}
172
173static inline void native_store_gdt(struct desc_ptr *dtr)
174{
175 asm volatile("sgdt %0":"=m" (*dtr));
176}
177
178static inline void native_store_idt(struct desc_ptr *dtr)
179{
180 asm volatile("sidt %0":"=m" (*dtr));
181}
182
183static inline unsigned long native_store_tr(void)
184{
185 unsigned long tr;
186 asm volatile("str %0":"=r" (tr));
187 return tr;
188}
189
190static inline void native_load_tls(struct thread_struct *t, unsigned int cpu)
191{
192 unsigned int i;
193 struct desc_struct *gdt = get_cpu_gdt_table(cpu);
194
195 for (i = 0; i < GDT_ENTRY_TLS_ENTRIES; i++)
196 gdt[GDT_ENTRY_TLS_MIN + i] = t->tls_array[i];
197}
198
Thomas Gleixner96a388d2007-10-11 11:20:03 +0200199#ifdef CONFIG_X86_32
200# include "desc_32.h"
201#else
202# include "desc_64.h"
203#endif
Glauber de Oliveira Costa80fbb692008-01-30 13:31:13 +0100204
Glauber de Oliveira Costa881c2972008-01-30 13:31:14 +0100205#define _LDT_empty(info) (\
206 (info)->base_addr == 0 && \
207 (info)->limit == 0 && \
208 (info)->contents == 0 && \
209 (info)->read_exec_only == 1 && \
210 (info)->seg_32bit == 0 && \
211 (info)->limit_in_pages == 0 && \
212 (info)->seg_not_present == 1 && \
213 (info)->useable == 0)
214
215#ifdef CONFIG_X86_64
216#define LDT_empty(info) (_LDT_empty(info) && ((info)->lm == 0))
217#else
218#define LDT_empty(info) (_LDT_empty(info))
219#endif
220
221static inline void clear_LDT(void)
222{
223 set_ldt(NULL, 0);
224}
225
226/*
227 * load one particular LDT into the current CPU
228 */
229static inline void load_LDT_nolock(mm_context_t *pc)
230{
231 set_ldt(pc->ldt, pc->size);
232}
233
234static inline void load_LDT(mm_context_t *pc)
235{
236 preempt_disable();
237 load_LDT_nolock(pc);
238 preempt_enable();
239}
240
Glauber de Oliveira Costacc697852008-01-30 13:31:14 +0100241static inline unsigned long get_desc_base(struct desc_struct *desc)
242{
243 return desc->base0 | ((desc->base1) << 16) | ((desc->base2) << 24);
244}
245
Glauber de Oliveira Costa881c2972008-01-30 13:31:14 +0100246#else
247/*
248 * GET_DESC_BASE reads the descriptor base of the specified segment.
249 *
250 * Args:
251 * idx - descriptor index
252 * gdt - GDT pointer
253 * base - 32bit register to which the base will be written
254 * lo_w - lo word of the "base" register
255 * lo_b - lo byte of the "base" register
256 * hi_b - hi byte of the low word of the "base" register
257 *
258 * Example:
259 * GET_DESC_BASE(GDT_ENTRY_ESPFIX_SS, %ebx, %eax, %ax, %al, %ah)
260 * Will read the base address of GDT_ENTRY_ESPFIX_SS and put it into %eax.
261 */
262#define GET_DESC_BASE(idx, gdt, base, lo_w, lo_b, hi_b) \
263 movb idx*8+4(gdt), lo_b; \
264 movb idx*8+7(gdt), hi_b; \
265 shll $16, base; \
266 movw idx*8+2(gdt), lo_w;
267
268
269#endif /* __ASSEMBLY__ */
270
Glauber de Oliveira Costa80fbb692008-01-30 13:31:13 +0100271#endif