1 #ifndef _ASM_X86_DESC_H
2 #define _ASM_X86_DESC_H
4 #include <asm/desc_defs.h>
9 #include <linux/percpu.h>
11 static inline void fill_ldt(struct desc_struct *desc, const struct user_desc *info)
13 desc->limit0 = info->limit & 0x0ffff;
15 desc->base0 = (info->base_addr & 0x0000ffff);
16 desc->base1 = (info->base_addr & 0x00ff0000) >> 16;
18 desc->type = (info->read_exec_only ^ 1) << 1;
19 desc->type |= info->contents << 2;
23 desc->p = info->seg_not_present ^ 1;
24 desc->limit = (info->limit & 0xf0000) >> 16;
25 desc->avl = info->useable;
26 desc->d = info->seg_32bit;
27 desc->g = info->limit_in_pages;
29 desc->base2 = (info->base_addr & 0xff000000) >> 24;
31 * Don't allow setting of the lm bit. It would confuse
32 * user_64bit_mode and would get overridden by sysret anyway.
37 extern struct desc_ptr idt_descr;
38 extern gate_desc idt_table[];
39 extern struct desc_ptr debug_idt_descr;
40 extern gate_desc debug_idt_table[];
43 struct desc_struct gdt[GDT_ENTRIES];
44 } __attribute__((aligned(PAGE_SIZE)));
46 DECLARE_PER_CPU_PAGE_ALIGNED(struct gdt_page, gdt_page);
48 static inline struct desc_struct *get_cpu_gdt_table(unsigned int cpu)
50 return per_cpu(gdt_page, cpu).gdt;
55 static inline void pack_gate(gate_desc *gate, unsigned type, unsigned long func,
56 unsigned dpl, unsigned ist, unsigned seg)
58 gate->offset_low = PTR_LOW(func);
59 gate->segment = __KERNEL_CS;
66 gate->offset_middle = PTR_MIDDLE(func);
67 gate->offset_high = PTR_HIGH(func);
71 static inline void pack_gate(gate_desc *gate, unsigned char type,
72 unsigned long base, unsigned dpl, unsigned flags,
75 gate->a = (seg << 16) | (base & 0xffff);
76 gate->b = (base & 0xffff0000) | (((0x80 | type | (dpl << 5)) & 0xff) << 8);
81 static inline int desc_empty(const void *ptr)
83 const u32 *desc = ptr;
85 return !(desc[0] | desc[1]);
88 #ifdef CONFIG_PARAVIRT
89 #include <asm/paravirt.h>
91 #define load_TR_desc() native_load_tr_desc()
92 #define load_gdt(dtr) native_load_gdt(dtr)
93 #define load_idt(dtr) native_load_idt(dtr)
94 #define load_tr(tr) asm volatile("ltr %0"::"m" (tr))
95 #define load_ldt(ldt) asm volatile("lldt %0"::"m" (ldt))
97 #define store_gdt(dtr) native_store_gdt(dtr)
98 #define store_idt(dtr) native_store_idt(dtr)
99 #define store_tr(tr) (tr = native_store_tr())
101 #define load_TLS(t, cpu) native_load_tls(t, cpu)
102 #define set_ldt native_set_ldt
104 #define write_ldt_entry(dt, entry, desc) native_write_ldt_entry(dt, entry, desc)
105 #define write_gdt_entry(dt, entry, desc, type) native_write_gdt_entry(dt, entry, desc, type)
106 #define write_idt_entry(dt, entry, g) native_write_idt_entry(dt, entry, g)
108 static inline void paravirt_alloc_ldt(struct desc_struct *ldt, unsigned entries)
112 static inline void paravirt_free_ldt(struct desc_struct *ldt, unsigned entries)
115 #endif /* CONFIG_PARAVIRT */
117 #define store_ldt(ldt) asm("sldt %0" : "=m"(ldt))
119 static inline void native_write_idt_entry(gate_desc *idt, int entry, const gate_desc *gate)
121 memcpy(&idt[entry], gate, sizeof(*gate));
124 static inline void native_write_ldt_entry(struct desc_struct *ldt, int entry, const void *desc)
126 memcpy(&ldt[entry], desc, 8);
130 native_write_gdt_entry(struct desc_struct *gdt, int entry, const void *desc, int type)
135 case DESC_TSS: size = sizeof(tss_desc); break;
136 case DESC_LDT: size = sizeof(ldt_desc); break;
137 default: size = sizeof(*gdt); break;
140 memcpy(&gdt[entry], desc, size);
143 static inline void pack_descriptor(struct desc_struct *desc, unsigned long base,
144 unsigned long limit, unsigned char type,
147 desc->a = ((base & 0xffff) << 16) | (limit & 0xffff);
148 desc->b = (base & 0xff000000) | ((base & 0xff0000) >> 16) |
149 (limit & 0x000f0000) | ((type & 0xff) << 8) |
150 ((flags & 0xf) << 20);
155 static inline void set_tssldt_descriptor(void *d, unsigned long addr, unsigned type, unsigned size)
158 struct ldttss_desc64 *desc = d;
160 memset(desc, 0, sizeof(*desc));
162 desc->limit0 = size & 0xFFFF;
163 desc->base0 = PTR_LOW(addr);
164 desc->base1 = PTR_MIDDLE(addr) & 0xFF;
167 desc->limit1 = (size >> 16) & 0xF;
168 desc->base2 = (PTR_MIDDLE(addr) >> 8) & 0xFF;
169 desc->base3 = PTR_HIGH(addr);
171 pack_descriptor((struct desc_struct *)d, addr, size, 0x80 | type, 0);
175 static inline void __set_tss_desc(unsigned cpu, unsigned int entry, void *addr)
177 struct desc_struct *d = get_cpu_gdt_table(cpu);
181 * sizeof(unsigned long) coming from an extra "long" at the end
182 * of the iobitmap. See tss_struct definition in processor.h
184 * -1? seg base+limit should be pointing to the address of the
187 set_tssldt_descriptor(&tss, (unsigned long)addr, DESC_TSS,
188 IO_BITMAP_OFFSET + IO_BITMAP_BYTES +
189 sizeof(unsigned long) - 1);
190 write_gdt_entry(d, entry, &tss, DESC_TSS);
193 #define set_tss_desc(cpu, addr) __set_tss_desc(cpu, GDT_ENTRY_TSS, addr)
195 static inline void native_set_ldt(const void *addr, unsigned int entries)
197 if (likely(entries == 0))
198 asm volatile("lldt %w0"::"q" (0));
200 unsigned cpu = smp_processor_id();
203 set_tssldt_descriptor(&ldt, (unsigned long)addr, DESC_LDT,
204 entries * LDT_ENTRY_SIZE - 1);
205 write_gdt_entry(get_cpu_gdt_table(cpu), GDT_ENTRY_LDT,
207 asm volatile("lldt %w0"::"q" (GDT_ENTRY_LDT*8));
211 static inline void native_load_tr_desc(void)
213 asm volatile("ltr %w0"::"q" (GDT_ENTRY_TSS*8));
216 static inline void native_load_gdt(const struct desc_ptr *dtr)
218 asm volatile("lgdt %0"::"m" (*dtr));
221 static inline void native_load_idt(const struct desc_ptr *dtr)
223 asm volatile("lidt %0"::"m" (*dtr));
226 static inline void native_store_gdt(struct desc_ptr *dtr)
228 asm volatile("sgdt %0":"=m" (*dtr));
231 static inline void native_store_idt(struct desc_ptr *dtr)
233 asm volatile("sidt %0":"=m" (*dtr));
236 static inline unsigned long native_store_tr(void)
240 asm volatile("str %0":"=r" (tr));
245 static inline void native_load_tls(struct thread_struct *t, unsigned int cpu)
247 struct desc_struct *gdt = get_cpu_gdt_table(cpu);
250 for (i = 0; i < GDT_ENTRY_TLS_ENTRIES; i++)
251 gdt[GDT_ENTRY_TLS_MIN + i] = t->tls_array[i];
254 #define _LDT_empty(info) \
255 ((info)->base_addr == 0 && \
256 (info)->limit == 0 && \
257 (info)->contents == 0 && \
258 (info)->read_exec_only == 1 && \
259 (info)->seg_32bit == 0 && \
260 (info)->limit_in_pages == 0 && \
261 (info)->seg_not_present == 1 && \
262 (info)->useable == 0)
265 #define LDT_empty(info) (_LDT_empty(info) && ((info)->lm == 0))
267 #define LDT_empty(info) (_LDT_empty(info))
270 static inline void clear_LDT(void)
276 * load one particular LDT into the current CPU
278 static inline void load_LDT_nolock(mm_context_t *pc)
280 set_ldt(pc->ldt, pc->size);
283 static inline void load_LDT(mm_context_t *pc)
290 static inline unsigned long get_desc_base(const struct desc_struct *desc)
292 return (unsigned)(desc->base0 | ((desc->base1) << 16) | ((desc->base2) << 24));
295 static inline void set_desc_base(struct desc_struct *desc, unsigned long base)
297 desc->base0 = base & 0xffff;
298 desc->base1 = (base >> 16) & 0xff;
299 desc->base2 = (base >> 24) & 0xff;
302 static inline unsigned long get_desc_limit(const struct desc_struct *desc)
304 return desc->limit0 | (desc->limit << 16);
307 static inline void set_desc_limit(struct desc_struct *desc, unsigned long limit)
309 desc->limit0 = limit & 0xffff;
310 desc->limit = (limit >> 16) & 0xf;
314 static inline void set_nmi_gate(int gate, void *addr)
318 pack_gate(&s, GATE_INTERRUPT, (unsigned long)addr, 0, 0, __KERNEL_CS);
319 write_idt_entry(debug_idt_table, gate, &s);
323 static inline void _set_gate(int gate, unsigned type, void *addr,
324 unsigned dpl, unsigned ist, unsigned seg)
328 pack_gate(&s, type, (unsigned long)addr, dpl, ist, seg);
330 * does not need to be atomic because it is only done once at
333 write_idt_entry(idt_table, gate, &s);
337 * This needs to use 'idt_table' rather than 'idt', and
338 * thus use the _nonmapped_ version of the IDT, as the
339 * Pentium F0 0F bugfix can have resulted in the mapped
340 * IDT being write-protected.
342 static inline void set_intr_gate(unsigned int n, void *addr)
344 BUG_ON((unsigned)n > 0xFF);
345 _set_gate(n, GATE_INTERRUPT, addr, 0, 0, __KERNEL_CS);
348 extern int first_system_vector;
349 /* used_vectors is BITMAP for irq is not managed by percpu vector_irq */
350 extern unsigned long used_vectors[];
352 static inline void alloc_system_vector(int vector)
354 if (!test_bit(vector, used_vectors)) {
355 set_bit(vector, used_vectors);
356 if (first_system_vector > vector)
357 first_system_vector = vector;
363 static inline void alloc_intr_gate(unsigned int n, void *addr)
365 alloc_system_vector(n);
366 set_intr_gate(n, addr);
370 * This routine sets up an interrupt gate at directory privilege level 3.
372 static inline void set_system_intr_gate(unsigned int n, void *addr)
374 BUG_ON((unsigned)n > 0xFF);
375 _set_gate(n, GATE_INTERRUPT, addr, 0x3, 0, __KERNEL_CS);
378 static inline void set_system_trap_gate(unsigned int n, void *addr)
380 BUG_ON((unsigned)n > 0xFF);
381 _set_gate(n, GATE_TRAP, addr, 0x3, 0, __KERNEL_CS);
384 static inline void set_trap_gate(unsigned int n, void *addr)
386 BUG_ON((unsigned)n > 0xFF);
387 _set_gate(n, GATE_TRAP, addr, 0, 0, __KERNEL_CS);
390 static inline void set_task_gate(unsigned int n, unsigned int gdt_entry)
392 BUG_ON((unsigned)n > 0xFF);
393 _set_gate(n, GATE_TASK, (void *)0, 0, 0, (gdt_entry<<3));
396 static inline void set_intr_gate_ist(int n, void *addr, unsigned ist)
398 BUG_ON((unsigned)n > 0xFF);
399 _set_gate(n, GATE_INTERRUPT, addr, 0, ist, __KERNEL_CS);
402 static inline void set_system_intr_gate_ist(int n, void *addr, unsigned ist)
404 BUG_ON((unsigned)n > 0xFF);
405 _set_gate(n, GATE_INTERRUPT, addr, 0x3, ist, __KERNEL_CS);
409 DECLARE_PER_CPU(u32, debug_idt_ctr);
410 static inline bool is_debug_idt_enabled(void)
412 if (this_cpu_read(debug_idt_ctr))
418 static inline void load_debug_idt(void)
420 load_idt((const struct desc_ptr *)&debug_idt_descr);
423 static inline bool is_debug_idt_enabled(void)
428 static inline void load_debug_idt(void)
434 * the load_current_idt() is called with interrupt disabled by local_irq_save()
435 * to avoid races. That way the IDT will always be set back to the expected
438 static inline void load_current_idt(void)
442 local_irq_save(flags);
443 if (is_debug_idt_enabled())
446 load_idt((const struct desc_ptr *)&idt_descr);
447 local_irq_restore(flags);
449 #endif /* _ASM_X86_DESC_H */