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()
34 * This is the ldt that every process will get unless we need
35 * something other than this.
37 extern struct desc_struct default_ldt[];
38 extern struct gate_struct idt_table[];
39 extern struct desc_ptr cpu_gdt_descr[];
41 static inline void write_ldt_entry(struct desc_struct *ldt,
42 int entry, u32 entry_low, u32 entry_high)
44 __u32 *lp = (__u32 *)((entry << 3) + (char *)ldt);
50 /* the cpu gdt accessor */
51 #define cpu_gdt(_cpu) ((struct desc_struct *)cpu_gdt_descr[_cpu].address)
53 static inline void load_gdt(const struct desc_ptr *ptr)
55 asm volatile("lgdt %w0"::"m" (*ptr));
58 static inline void store_gdt(struct desc_ptr *ptr)
60 asm("sgdt %w0":"=m" (*ptr));
63 static inline void _set_gate(void *adr, unsigned type, unsigned long func,
64 unsigned dpl, unsigned ist)
68 s.offset_low = PTR_LOW(func);
69 s.segment = __KERNEL_CS;
76 s.offset_middle = PTR_MIDDLE(func);
77 s.offset_high = PTR_HIGH(func);
79 * does not need to be atomic because it is only done once at
85 static inline void set_intr_gate(int nr, void *func)
87 BUG_ON((unsigned)nr > 0xFF);
88 _set_gate(&idt_table[nr], GATE_INTERRUPT, (unsigned long) func, 0, 0);
91 static inline void set_intr_gate_ist(int nr, void *func, unsigned ist)
93 BUG_ON((unsigned)nr > 0xFF);
94 _set_gate(&idt_table[nr], GATE_INTERRUPT, (unsigned long) func, 0, ist);
97 static inline void set_system_gate(int nr, void *func)
99 BUG_ON((unsigned)nr > 0xFF);
100 _set_gate(&idt_table[nr], GATE_INTERRUPT, (unsigned long) func, 3, 0);
103 static inline void set_system_gate_ist(int nr, void *func, unsigned ist)
105 _set_gate(&idt_table[nr], GATE_INTERRUPT, (unsigned long) func, 3, ist);
108 static inline void load_idt(const struct desc_ptr *ptr)
110 asm volatile("lidt %w0"::"m" (*ptr));
113 static inline void store_idt(struct desc_ptr *dtr)
115 asm("sidt %w0":"=m" (*dtr));
118 static inline void set_tssldt_descriptor(void *ptr, unsigned long tss,
119 unsigned type, unsigned size)
121 struct ldttss_desc d;
123 memset(&d, 0, sizeof(d));
124 d.limit0 = size & 0xFFFF;
125 d.base0 = PTR_LOW(tss);
126 d.base1 = PTR_MIDDLE(tss) & 0xFF;
129 d.limit1 = (size >> 16) & 0xF;
130 d.base2 = (PTR_MIDDLE(tss) >> 8) & 0xFF;
131 d.base3 = PTR_HIGH(tss);
135 static inline void set_tss_desc(unsigned cpu, void *addr)
138 * sizeof(unsigned long) coming from an extra "long" at the end
139 * of the iobitmap. See tss_struct definition in processor.h
141 * -1? seg base+limit should be pointing to the address of the
144 set_tssldt_descriptor(&cpu_gdt(cpu)[GDT_ENTRY_TSS],
145 (unsigned long)addr, DESC_TSS,
146 IO_BITMAP_OFFSET + IO_BITMAP_BYTES + sizeof(unsigned long) - 1);
149 static inline void set_ldt_desc(unsigned cpu, void *addr, int size)
151 set_tssldt_descriptor(&cpu_gdt(cpu)[GDT_ENTRY_LDT], (unsigned long)addr,
152 DESC_LDT, size * 8 - 1);
155 #define LDT_entry_a(info) \
156 ((((info)->base_addr & 0x0000ffff) << 16) | ((info)->limit & 0x0ffff))
157 /* Don't allow setting of the lm bit. It is useless anyways because
158 64bit system calls require __USER_CS. */
159 #define LDT_entry_b(info) \
160 (((info)->base_addr & 0xff000000) | \
161 (((info)->base_addr & 0x00ff0000) >> 16) | \
162 ((info)->limit & 0xf0000) | \
163 (((info)->read_exec_only ^ 1) << 9) | \
164 ((info)->contents << 10) | \
165 (((info)->seg_not_present ^ 1) << 15) | \
166 ((info)->seg_32bit << 22) | \
167 ((info)->limit_in_pages << 23) | \
168 ((info)->useable << 20) | \
169 /* ((info)->lm << 21) | */ \
172 #define LDT_empty(info) (\
173 (info)->base_addr == 0 && \
174 (info)->limit == 0 && \
175 (info)->contents == 0 && \
176 (info)->read_exec_only == 1 && \
177 (info)->seg_32bit == 0 && \
178 (info)->limit_in_pages == 0 && \
179 (info)->seg_not_present == 1 && \
180 (info)->useable == 0 && \
183 static inline void load_TLS(struct thread_struct *t, unsigned int cpu)
186 u64 *gdt = (u64 *)(cpu_gdt(cpu) + GDT_ENTRY_TLS_MIN);
188 for (i = 0; i < GDT_ENTRY_TLS_ENTRIES; i++)
189 gdt[i] = t->tls_array[i];
193 * load one particular LDT into the current CPU
195 static inline void load_LDT_nolock(mm_context_t *pc, int cpu)
197 int count = pc->size;
199 if (likely(!count)) {
204 set_ldt_desc(cpu, pc->ldt, count);
208 static inline void load_LDT(mm_context_t *pc)
212 load_LDT_nolock(pc, cpu);
216 extern struct desc_ptr idt_descr;
218 static inline unsigned long get_desc_base(const void *ptr)
220 const u32 *desc = ptr;
222 base = ((desc[0] >> 16) & 0x0000ffff) |
223 ((desc[1] << 16) & 0x00ff0000) |
224 (desc[1] & 0xff000000);
228 #endif /* !__ASSEMBLY__ */