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 extern struct desc_ptr idt_descr, cpu_gdt_descr[NR_CPUS];
21 #define load_TR_desc() asm volatile("ltr %w0"::"r" (GDT_ENTRY_TSS*8))
22 #define load_LDT_desc() asm volatile("lldt %w0"::"r" (GDT_ENTRY_LDT*8))
24 static inline void clear_LDT(void)
29 * NB. We load the default_ldt for lcall7/27 handling on demand, as
30 * it slows down context switching. Noone uses it anyway.
32 cpu = cpu; /* XXX avoid compiler warning */
38 * This is the ldt that every process will get unless we need
39 * something other than this.
41 extern struct desc_struct default_ldt[];
42 #ifndef CONFIG_X86_NO_IDT
43 extern struct gate_struct idt_table[];
45 extern struct desc_ptr cpu_gdt_descr[];
47 /* the cpu gdt accessor */
48 #define cpu_gdt(_cpu) ((struct desc_struct *)cpu_gdt_descr[_cpu].address)
50 static inline void _set_gate(void *adr, unsigned type, unsigned long func, unsigned dpl, unsigned ist)
53 s.offset_low = PTR_LOW(func);
54 s.segment = __KERNEL_CS;
61 s.offset_middle = PTR_MIDDLE(func);
62 s.offset_high = PTR_HIGH(func);
63 /* does not need to be atomic because it is only done once at setup time */
67 #ifndef CONFIG_X86_NO_IDT
68 static inline void set_intr_gate(int nr, void *func)
70 BUG_ON((unsigned)nr > 0xFF);
71 _set_gate(&idt_table[nr], GATE_INTERRUPT, (unsigned long) func, 0, 0);
74 static inline void set_intr_gate_ist(int nr, void *func, unsigned ist)
76 BUG_ON((unsigned)nr > 0xFF);
77 _set_gate(&idt_table[nr], GATE_INTERRUPT, (unsigned long) func, 0, ist);
80 static inline void set_system_gate(int nr, void *func)
82 BUG_ON((unsigned)nr > 0xFF);
83 _set_gate(&idt_table[nr], GATE_INTERRUPT, (unsigned long) func, 3, 0);
86 static inline void set_system_gate_ist(int nr, void *func, unsigned ist)
88 _set_gate(&idt_table[nr], GATE_INTERRUPT, (unsigned long) func, 3, ist);
92 static inline void set_tssldt_descriptor(void *ptr, unsigned long tss, unsigned type,
96 memset(&d,0,sizeof(d));
97 d.limit0 = size & 0xFFFF;
98 d.base0 = PTR_LOW(tss);
99 d.base1 = PTR_MIDDLE(tss) & 0xFF;
102 d.limit1 = (size >> 16) & 0xF;
103 d.base2 = (PTR_MIDDLE(tss) >> 8) & 0xFF;
104 d.base3 = PTR_HIGH(tss);
108 #ifndef CONFIG_X86_NO_TSS
109 static inline void set_tss_desc(unsigned cpu, void *addr)
112 * sizeof(unsigned long) coming from an extra "long" at the end
113 * of the iobitmap. See tss_struct definition in processor.h
115 * -1? seg base+limit should be pointing to the address of the
118 set_tssldt_descriptor(&cpu_gdt(cpu)[GDT_ENTRY_TSS],
119 (unsigned long)addr, DESC_TSS,
120 IO_BITMAP_OFFSET + IO_BITMAP_BYTES + sizeof(unsigned long) - 1);
124 static inline void set_ldt_desc(unsigned cpu, void *addr, int size)
126 set_tssldt_descriptor(&cpu_gdt(cpu)[GDT_ENTRY_LDT], (unsigned long)addr,
127 DESC_LDT, size * 8 - 1);
130 static inline void set_seg_base(unsigned cpu, int entry, void *base)
132 struct desc_struct *d = &cpu_gdt(cpu)[entry];
133 u32 addr = (u32)(u64)base;
134 BUG_ON((u64)base >> 32);
135 d->base0 = addr & 0xffff;
136 d->base1 = (addr >> 16) & 0xff;
137 d->base2 = (addr >> 24) & 0xff;
140 #define LDT_entry_a(info) \
141 ((((info)->base_addr & 0x0000ffff) << 16) | ((info)->limit & 0x0ffff))
142 /* Don't allow setting of the lm bit. It is useless anyways because
143 64bit system calls require __USER_CS. */
144 #define LDT_entry_b(info) \
145 (((info)->base_addr & 0xff000000) | \
146 (((info)->base_addr & 0x00ff0000) >> 16) | \
147 ((info)->limit & 0xf0000) | \
148 (((info)->read_exec_only ^ 1) << 9) | \
149 ((info)->contents << 10) | \
150 (((info)->seg_not_present ^ 1) << 15) | \
151 ((info)->seg_32bit << 22) | \
152 ((info)->limit_in_pages << 23) | \
153 ((info)->useable << 20) | \
154 /* ((info)->lm << 21) | */ \
157 #define LDT_empty(info) (\
158 (info)->base_addr == 0 && \
159 (info)->limit == 0 && \
160 (info)->contents == 0 && \
161 (info)->read_exec_only == 1 && \
162 (info)->seg_32bit == 0 && \
163 (info)->limit_in_pages == 0 && \
164 (info)->seg_not_present == 1 && \
165 (info)->useable == 0 && \
169 # error update this code.
172 static inline void load_TLS(struct thread_struct *t, unsigned int cpu)
175 u64 *gdt = (u64 *)(cpu_gdt(cpu) + GDT_ENTRY_TLS_MIN);
176 gdt[0] = t->tls_array[0];
177 gdt[1] = t->tls_array[1];
178 gdt[2] = t->tls_array[2];
181 HYPERVISOR_update_descriptor(virt_to_machine(&cpu_gdt(cpu)[GDT_ENTRY_TLS_MIN + i]), t->tls_array[i])
188 * load one particular LDT into the current CPU
190 static inline void load_LDT_nolock (mm_context_t *pc, int cpu)
192 void *segments = pc->ldt;
193 int count = pc->size;
198 xen_set_ldt((unsigned long)segments, count);
201 static inline void load_LDT(mm_context_t *pc)
204 load_LDT_nolock(pc, cpu);
208 extern struct desc_ptr idt_descr;
210 #endif /* !__ASSEMBLY__ */