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Diffstat (limited to 'include/asm-x86_64/desc.h')
| -rw-r--r-- | include/asm-x86_64/desc.h | 217 |
1 files changed, 217 insertions, 0 deletions
diff --git a/include/asm-x86_64/desc.h b/include/asm-x86_64/desc.h new file mode 100644 index 00000000000..6aefb9c0280 --- /dev/null +++ b/include/asm-x86_64/desc.h @@ -0,0 +1,217 @@ +/* Written 2000 by Andi Kleen */ +#ifndef __ARCH_DESC_H +#define __ARCH_DESC_H + +#include <linux/threads.h> +#include <asm/ldt.h> + +#ifndef __ASSEMBLY__ + +#include <linux/string.h> +#include <asm/segment.h> +#include <asm/mmu.h> + +// 8 byte segment descriptor +struct desc_struct { + u16 limit0; + u16 base0; + unsigned base1 : 8, type : 4, s : 1, dpl : 2, p : 1; + unsigned limit : 4, avl : 1, l : 1, d : 1, g : 1, base2 : 8; +} __attribute__((packed)); + +struct n_desc_struct { + unsigned int a,b; +}; + +extern struct desc_struct cpu_gdt_table[NR_CPUS][GDT_ENTRIES]; + +enum { + GATE_INTERRUPT = 0xE, + GATE_TRAP = 0xF, + GATE_CALL = 0xC, +}; + +// 16byte gate +struct gate_struct { + u16 offset_low; + u16 segment; + unsigned ist : 3, zero0 : 5, type : 5, dpl : 2, p : 1; + u16 offset_middle; + u32 offset_high; + u32 zero1; +} __attribute__((packed)); + +#define PTR_LOW(x) ((unsigned long)(x) & 0xFFFF) +#define PTR_MIDDLE(x) (((unsigned long)(x) >> 16) & 0xFFFF) +#define PTR_HIGH(x) ((unsigned long)(x) >> 32) + +enum { + DESC_TSS = 0x9, + DESC_LDT = 0x2, +}; + +// LDT or TSS descriptor in the GDT. 16 bytes. +struct ldttss_desc { + u16 limit0; + u16 base0; + unsigned base1 : 8, type : 5, dpl : 2, p : 1; + unsigned limit1 : 4, zero0 : 3, g : 1, base2 : 8; + u32 base3; + u32 zero1; +} __attribute__((packed)); + +struct desc_ptr { + unsigned short size; + unsigned long address; +} __attribute__((packed)) ; + +#define load_TR_desc() asm volatile("ltr %w0"::"r" (GDT_ENTRY_TSS*8)) +#define load_LDT_desc() asm volatile("lldt %w0"::"r" (GDT_ENTRY_LDT*8)) +#define clear_LDT() asm volatile("lldt %w0"::"r" (0)) + +/* + * This is the ldt that every process will get unless we need + * something other than this. + */ +extern struct desc_struct default_ldt[]; +extern struct gate_struct idt_table[]; + +static inline void _set_gate(void *adr, unsigned type, unsigned long func, unsigned dpl, unsigned ist) +{ + struct gate_struct s; + s.offset_low = PTR_LOW(func); + s.segment = __KERNEL_CS; + s.ist = ist; + s.p = 1; + s.dpl = dpl; + s.zero0 = 0; + s.zero1 = 0; + s.type = type; + s.offset_middle = PTR_MIDDLE(func); + s.offset_high = PTR_HIGH(func); + /* does not need to be atomic because it is only done once at setup time */ + memcpy(adr, &s, 16); +} + +static inline void set_intr_gate(int nr, void *func) +{ + _set_gate(&idt_table[nr], GATE_INTERRUPT, (unsigned long) func, 0, 0); +} + +static inline void set_intr_gate_ist(int nr, void *func, unsigned ist) +{ + _set_gate(&idt_table[nr], GATE_INTERRUPT, (unsigned long) func, 0, ist); +} + +static inline void set_system_gate(int nr, void *func) +{ + _set_gate(&idt_table[nr], GATE_INTERRUPT, (unsigned long) func, 3, 0); +} + +static inline void set_tssldt_descriptor(void *ptr, unsigned long tss, unsigned type, + unsigned size) +{ + struct ldttss_desc d; + memset(&d,0,sizeof(d)); + d.limit0 = size & 0xFFFF; + d.base0 = PTR_LOW(tss); + d.base1 = PTR_MIDDLE(tss) & 0xFF; + d.type = type; + d.p = 1; + d.limit1 = (size >> 16) & 0xF; + d.base2 = (PTR_MIDDLE(tss) >> 8) & 0xFF; + d.base3 = PTR_HIGH(tss); + memcpy(ptr, &d, 16); +} + +static inline void set_tss_desc(unsigned cpu, void *addr) +{ + set_tssldt_descriptor(&cpu_gdt_table[cpu][GDT_ENTRY_TSS], (unsigned long)addr, + DESC_TSS, + sizeof(struct tss_struct) - 1); +} + +static inline void set_ldt_desc(unsigned cpu, void *addr, int size) +{ + set_tssldt_descriptor(&cpu_gdt_table[cpu][GDT_ENTRY_LDT], (unsigned long)addr, + DESC_LDT, size * 8 - 1); +} + +static inline void set_seg_base(unsigned cpu, int entry, void *base) +{ + struct desc_struct *d = &cpu_gdt_table[cpu][entry]; + u32 addr = (u32)(u64)base; + BUG_ON((u64)base >> 32); + d->base0 = addr & 0xffff; + d->base1 = (addr >> 16) & 0xff; + d->base2 = (addr >> 24) & 0xff; +} + +#define LDT_entry_a(info) \ + ((((info)->base_addr & 0x0000ffff) << 16) | ((info)->limit & 0x0ffff)) +/* Don't allow setting of the lm bit. It is useless anyways because + 64bit system calls require __USER_CS. */ +#define LDT_entry_b(info) \ + (((info)->base_addr & 0xff000000) | \ + (((info)->base_addr & 0x00ff0000) >> 16) | \ + ((info)->limit & 0xf0000) | \ + (((info)->read_exec_only ^ 1) << 9) | \ + ((info)->contents << 10) | \ + (((info)->seg_not_present ^ 1) << 15) | \ + ((info)->seg_32bit << 22) | \ + ((info)->limit_in_pages << 23) | \ + ((info)->useable << 20) | \ + /* ((info)->lm << 21) | */ \ + 0x7000) + +#define LDT_empty(info) (\ + (info)->base_addr == 0 && \ + (info)->limit == 0 && \ + (info)->contents == 0 && \ + (info)->read_exec_only == 1 && \ + (info)->seg_32bit == 0 && \ + (info)->limit_in_pages == 0 && \ + (info)->seg_not_present == 1 && \ + (info)->useable == 0 && \ + (info)->lm == 0) + +#if TLS_SIZE != 24 +# error update this code. +#endif + +static inline void load_TLS(struct thread_struct *t, unsigned int cpu) +{ + u64 *gdt = (u64 *)(cpu_gdt_table[cpu] + GDT_ENTRY_TLS_MIN); + gdt[0] = t->tls_array[0]; + gdt[1] = t->tls_array[1]; + gdt[2] = t->tls_array[2]; +} + +/* + * load one particular LDT into the current CPU + */ +extern inline void load_LDT_nolock (mm_context_t *pc, int cpu) +{ + int count = pc->size; + + if (likely(!count)) { + clear_LDT(); + return; + } + + set_ldt_desc(cpu, pc->ldt, count); + load_LDT_desc(); +} + +static inline void load_LDT(mm_context_t *pc) +{ + int cpu = get_cpu(); + load_LDT_nolock(pc, cpu); + put_cpu(); +} + +extern struct desc_ptr idt_descr; + +#endif /* !__ASSEMBLY__ */ + +#endif |