1 /* Written 2000 by Andi Kleen */
5 #include <linux/threads.h>
10 #include <linux/string.h>
11 #include <linux/smp.h>
12 #include <asm/desc_defs.h>
14 #include <asm/segment.h>
17 extern struct desc_struct cpu_gdt_table[GDT_ENTRIES];
19 #define load_TR_desc() asm volatile("ltr %w0"::"r" (GDT_ENTRY_TSS*8))
20 #define load_LDT_desc() asm volatile("lldt %w0"::"r" (GDT_ENTRY_LDT*8))
21 #define clear_LDT() asm volatile("lldt %w0"::"r" (0))
23 static inline unsigned long __store_tr(void)
27 asm volatile ("str %w0":"=r" (tr));
31 #define store_tr(tr) (tr) = __store_tr()
33 extern gate_desc idt_table[];
34 extern struct desc_ptr cpu_gdt_descr[];
36 static inline void write_ldt_entry(struct desc_struct *ldt,
39 memcpy(&ldt[entry], ptr, 8);
42 /* the cpu gdt accessor */
43 #define get_cpu_gdt_table(x) ((struct desc_struct *)cpu_gdt_descr[x].address)
45 static inline void load_gdt(const struct desc_ptr *ptr)
47 asm volatile("lgdt %w0"::"m" (*ptr));
50 static inline void store_gdt(struct desc_ptr *ptr)
52 asm("sgdt %w0":"=m" (*ptr));
55 static inline void _set_gate(void *adr, unsigned type, unsigned long func,
56 unsigned dpl, unsigned ist)
60 s.offset_low = PTR_LOW(func);
61 s.segment = __KERNEL_CS;
68 s.offset_middle = PTR_MIDDLE(func);
69 s.offset_high = PTR_HIGH(func);
71 * does not need to be atomic because it is only done once at
77 static inline void set_intr_gate(int nr, void *func)
79 BUG_ON((unsigned)nr > 0xFF);
80 _set_gate(&idt_table[nr], GATE_INTERRUPT, (unsigned long) func, 0, 0);
83 static inline void set_intr_gate_ist(int nr, void *func, unsigned ist)
85 BUG_ON((unsigned)nr > 0xFF);
86 _set_gate(&idt_table[nr], GATE_INTERRUPT, (unsigned long) func, 0, ist);
89 static inline void set_system_gate(int nr, void *func)
91 BUG_ON((unsigned)nr > 0xFF);
92 _set_gate(&idt_table[nr], GATE_INTERRUPT, (unsigned long) func, 3, 0);
95 static inline void set_system_gate_ist(int nr, void *func, unsigned ist)
97 _set_gate(&idt_table[nr], GATE_INTERRUPT, (unsigned long) func, 3, ist);
100 static inline void load_idt(const struct desc_ptr *ptr)
102 asm volatile("lidt %w0"::"m" (*ptr));
105 static inline void store_idt(struct desc_ptr *dtr)
107 asm("sidt %w0":"=m" (*dtr));
110 static inline void set_tssldt_descriptor(void *ptr, unsigned long tss,
111 unsigned type, unsigned size)
113 struct ldttss_desc64 d;
115 memset(&d, 0, sizeof(d));
116 d.limit0 = size & 0xFFFF;
117 d.base0 = PTR_LOW(tss);
118 d.base1 = PTR_MIDDLE(tss) & 0xFF;
121 d.limit1 = (size >> 16) & 0xF;
122 d.base2 = (PTR_MIDDLE(tss) >> 8) & 0xFF;
123 d.base3 = PTR_HIGH(tss);
127 static inline void set_tss_desc(unsigned cpu, void *addr)
130 * sizeof(unsigned long) coming from an extra "long" at the end
131 * of the iobitmap. See tss_struct definition in processor.h
133 * -1? seg base+limit should be pointing to the address of the
136 set_tssldt_descriptor(&get_cpu_gdt_table(cpu)[GDT_ENTRY_TSS],
137 (unsigned long)addr, DESC_TSS,
138 IO_BITMAP_OFFSET + IO_BITMAP_BYTES + sizeof(unsigned long) - 1);
141 static inline void set_ldt_desc(unsigned cpu, void *addr, int size)
143 set_tssldt_descriptor(&get_cpu_gdt_table(cpu)[GDT_ENTRY_LDT],
144 (unsigned long)addr, DESC_LDT, size * 8 - 1);
147 #define LDT_empty(info) (\
148 (info)->base_addr == 0 && \
149 (info)->limit == 0 && \
150 (info)->contents == 0 && \
151 (info)->read_exec_only == 1 && \
152 (info)->seg_32bit == 0 && \
153 (info)->limit_in_pages == 0 && \
154 (info)->seg_not_present == 1 && \
155 (info)->useable == 0 && \
158 static inline void load_TLS(struct thread_struct *t, unsigned int cpu)
161 u64 *gdt = (u64 *)(get_cpu_gdt_table(cpu) + GDT_ENTRY_TLS_MIN);
163 for (i = 0; i < GDT_ENTRY_TLS_ENTRIES; i++)
164 gdt[i] = t->tls_array[i];
168 * load one particular LDT into the current CPU
170 static inline void load_LDT_nolock(mm_context_t *pc, int cpu)
172 int count = pc->size;
174 if (likely(!count)) {
179 set_ldt_desc(cpu, pc->ldt, count);
183 static inline void load_LDT(mm_context_t *pc)
187 load_LDT_nolock(pc, cpu);
191 extern struct desc_ptr idt_descr;
193 static inline unsigned long get_desc_base(const void *ptr)
195 const u32 *desc = ptr;
197 base = ((desc[0] >> 16) & 0x0000ffff) |
198 ((desc[1] << 16) & 0x00ff0000) |
199 (desc[1] & 0xff000000);
203 #endif /* !__ASSEMBLY__ */