include/asm-x86_64/desc.h

   1 /* Written 2000 by Andi Kleen */
   2 #ifndef __ARCH_DESC_H
   3 #define __ARCH_DESC_H
   4
   5 #include <linux/threads.h>
   6 #include <asm/ldt.h>
   7
   8 #ifndef __ASSEMBLY__
   9
  10 #include <linux/string.h>
  11 #include <linux/smp.h>
  12 #include <asm/desc_defs.h>
  13
  14 #include <asm/segment.h>
  15 #include <asm/mmu.h>
  16
  17 extern struct desc_struct cpu_gdt_table[GDT_ENTRIES];
  18
  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))
  22
  23 /*
  24  * This is the ldt that every process will get unless we need
  25  * something other than this.
  26  */
  27 extern struct desc_struct default_ldt[];
  28 extern struct gate_struct idt_table[];
  29 extern struct desc_ptr cpu_gdt_descr[];
  30
  31 /* the cpu gdt accessor */
  32 #define cpu_gdt(_cpu) ((struct desc_struct *)cpu_gdt_descr[_cpu].address)
  33
  34 static inline void _set_gate(void *adr, unsigned type, unsigned long func, unsigned dpl, unsigned ist)
  35 {
  36         struct gate_struct s;
  37         s.offset_low = PTR_LOW(func);
  38         s.segment = __KERNEL_CS;
  39         s.ist = ist;
  40         s.p = 1;
  41         s.dpl = dpl;
  42         s.zero0 = 0;
  43         s.zero1 = 0;
  44         s.type = type;
  45         s.offset_middle = PTR_MIDDLE(func);
  46         s.offset_high = PTR_HIGH(func);
  47         /* does not need to be atomic because it is only done once at setup time */
  48         memcpy(adr, &s, 16);
  49 }
  50
  51 static inline void set_intr_gate(int nr, void *func)
  52 {
  53         BUG_ON((unsigned)nr > 0xFF);
  54         _set_gate(&idt_table[nr], GATE_INTERRUPT, (unsigned long) func, 0, 0);
  55 }
  56
  57 static inline void set_intr_gate_ist(int nr, void *func, unsigned ist)
  58 {
  59         BUG_ON((unsigned)nr > 0xFF);
  60         _set_gate(&idt_table[nr], GATE_INTERRUPT, (unsigned long) func, 0, ist);
  61 }
  62
  63 static inline void set_system_gate(int nr, void *func)
  64 {
  65         BUG_ON((unsigned)nr > 0xFF);
  66         _set_gate(&idt_table[nr], GATE_INTERRUPT, (unsigned long) func, 3, 0);
  67 }
  68
  69 static inline void set_system_gate_ist(int nr, void *func, unsigned ist)
  70 {
  71         _set_gate(&idt_table[nr], GATE_INTERRUPT, (unsigned long) func, 3, ist);
  72 }
  73
  74 static inline void set_tssldt_descriptor(void *ptr, unsigned long tss, unsigned type,
  75                                          unsigned size)
  76 {
  77         struct ldttss_desc d;
  78         memset(&d,0,sizeof(d));
  79         d.limit0 = size & 0xFFFF;
  80         d.base0 = PTR_LOW(tss);
  81         d.base1 = PTR_MIDDLE(tss) & 0xFF;
  82         d.type = type;
  83         d.p = 1;
  84         d.limit1 = (size >> 16) & 0xF;
  85         d.base2 = (PTR_MIDDLE(tss) >> 8) & 0xFF;
  86         d.base3 = PTR_HIGH(tss);
  87         memcpy(ptr, &d, 16);
  88 }
  89
  90 static inline void set_tss_desc(unsigned cpu, void *addr)
  91 {
  92         /*
  93          * sizeof(unsigned long) coming from an extra "long" at the end
  94          * of the iobitmap. See tss_struct definition in processor.h
  95          *
  96          * -1? seg base+limit should be pointing to the address of the
  97          * last valid byte
  98          */
  99         set_tssldt_descriptor(&cpu_gdt(cpu)[GDT_ENTRY_TSS],
 100                 (unsigned long)addr, DESC_TSS,
 101                 IO_BITMAP_OFFSET + IO_BITMAP_BYTES + sizeof(unsigned long) - 1);
 102 }
 103
 104 static inline void set_ldt_desc(unsigned cpu, void *addr, int size)
 105 {
 106         set_tssldt_descriptor(&cpu_gdt(cpu)[GDT_ENTRY_LDT], (unsigned long)addr,
 107                               DESC_LDT, size * 8 - 1);
 108 }
 109
 110 static inline void set_seg_base(unsigned cpu, int entry, void *base)
 111 {
 112         struct desc_struct *d = &cpu_gdt(cpu)[entry];
 113         u32 addr = (u32)(u64)base;
 114         BUG_ON((u64)base >> 32);
 115         d->base0 = addr & 0xffff;
 116         d->base1 = (addr >> 16) & 0xff;
 117         d->base2 = (addr >> 24) & 0xff;
 118 }
 119
 120 #define LDT_entry_a(info) \
 121         ((((info)->base_addr & 0x0000ffff) << 16) | ((info)->limit & 0x0ffff))
 122 /* Don't allow setting of the lm bit. It is useless anyways because
 123    64bit system calls require __USER_CS. */
 124 #define LDT_entry_b(info) \
 125         (((info)->base_addr & 0xff000000) | \
 126         (((info)->base_addr & 0x00ff0000) >> 16) | \
 127         ((info)->limit & 0xf0000) | \
 128         (((info)->read_exec_only ^ 1) << 9) | \
 129         ((info)->contents << 10) | \
 130         (((info)->seg_not_present ^ 1) << 15) | \
 131         ((info)->seg_32bit << 22) | \
 132         ((info)->limit_in_pages << 23) | \
 133         ((info)->useable << 20) | \
 134         /* ((info)->lm << 21) | */ \
 135         0x7000)
 136
 137 #define LDT_empty(info) (\
 138         (info)->base_addr       == 0    && \
 139         (info)->limit           == 0    && \
 140         (info)->contents        == 0    && \
 141         (info)->read_exec_only  == 1    && \
 142         (info)->seg_32bit       == 0    && \
 143         (info)->limit_in_pages  == 0    && \
 144         (info)->seg_not_present == 1    && \
 145         (info)->useable         == 0    && \
 146         (info)->lm              == 0)
 147
 148 #if TLS_SIZE != 24
 149 # error update this code.
 150 #endif
 151
 152 static inline void load_TLS(struct thread_struct *t, unsigned int cpu)
 153 {
 154         u64 *gdt = (u64 *)(cpu_gdt(cpu) + GDT_ENTRY_TLS_MIN);
 155         gdt[0] = t->tls_array[0];
 156         gdt[1] = t->tls_array[1];
 157         gdt[2] = t->tls_array[2];
 158 }
 159
 160 /*
 161  * load one particular LDT into the current CPU
 162  */
 163 static inline void load_LDT_nolock (mm_context_t *pc, int cpu)
 164 {
 165         int count = pc->size;
 166
 167         if (likely(!count)) {
 168                 clear_LDT();
 169                 return;
 170         }
 171
 172         set_ldt_desc(cpu, pc->ldt, count);
 173         load_LDT_desc();
 174 }
 175
 176 static inline void load_LDT(mm_context_t *pc)
 177 {
 178         int cpu = get_cpu();
 179         load_LDT_nolock(pc, cpu);
 180         put_cpu();
 181 }
 182
 183 extern struct desc_ptr idt_descr;
 184
 185 #endif /* !__ASSEMBLY__ */
 186
 187 #endif