diff options
Diffstat (limited to 'include/asm-i386/desc.h')
| -rw-r--r-- | include/asm-i386/desc.h | 144 |
1 files changed, 144 insertions, 0 deletions
diff --git a/include/asm-i386/desc.h b/include/asm-i386/desc.h new file mode 100644 index 000000000000..11e67811a990 --- /dev/null +++ b/include/asm-i386/desc.h @@ -0,0 +1,144 @@ +#ifndef __ARCH_DESC_H +#define __ARCH_DESC_H + +#include <asm/ldt.h> +#include <asm/segment.h> + +#define CPU_16BIT_STACK_SIZE 1024 + +#ifndef __ASSEMBLY__ + +#include <linux/preempt.h> +#include <linux/smp.h> +#include <linux/percpu.h> + +#include <asm/mmu.h> + +extern struct desc_struct cpu_gdt_table[GDT_ENTRIES]; +DECLARE_PER_CPU(struct desc_struct, cpu_gdt_table[GDT_ENTRIES]); + +DECLARE_PER_CPU(unsigned char, cpu_16bit_stack[CPU_16BIT_STACK_SIZE]); + +struct Xgt_desc_struct { + unsigned short size; + unsigned long address __attribute__((packed)); + unsigned short pad; +} __attribute__ ((packed)); + +extern struct Xgt_desc_struct idt_descr, cpu_gdt_descr[NR_CPUS]; + +#define load_TR_desc() __asm__ __volatile__("ltr %%ax"::"a" (GDT_ENTRY_TSS*8)) +#define load_LDT_desc() __asm__ __volatile__("lldt %%ax"::"a" (GDT_ENTRY_LDT*8)) + +/* + * This is the ldt that every process will get unless we need + * something other than this. + */ +extern struct desc_struct default_ldt[]; +extern void set_intr_gate(unsigned int irq, void * addr); + +#define _set_tssldt_desc(n,addr,limit,type) \ +__asm__ __volatile__ ("movw %w3,0(%2)\n\t" \ + "movw %%ax,2(%2)\n\t" \ + "rorl $16,%%eax\n\t" \ + "movb %%al,4(%2)\n\t" \ + "movb %4,5(%2)\n\t" \ + "movb $0,6(%2)\n\t" \ + "movb %%ah,7(%2)\n\t" \ + "rorl $16,%%eax" \ + : "=m"(*(n)) : "a" (addr), "r"(n), "ir"(limit), "i"(type)) + +static inline void __set_tss_desc(unsigned int cpu, unsigned int entry, void *addr) +{ + _set_tssldt_desc(&per_cpu(cpu_gdt_table, cpu)[entry], (int)addr, + offsetof(struct tss_struct, __cacheline_filler) - 1, 0x89); +} + +#define set_tss_desc(cpu,addr) __set_tss_desc(cpu, GDT_ENTRY_TSS, addr) + +static inline void set_ldt_desc(unsigned int cpu, void *addr, unsigned int size) +{ + _set_tssldt_desc(&per_cpu(cpu_gdt_table, cpu)[GDT_ENTRY_LDT], (int)addr, ((size << 3)-1), 0x82); +} + +#define LDT_entry_a(info) \ + ((((info)->base_addr & 0x0000ffff) << 16) | ((info)->limit & 0x0ffff)) + +#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) | \ + 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 ) + +#if TLS_SIZE != 24 +# error update this code. +#endif + +static inline void load_TLS(struct thread_struct *t, unsigned int cpu) +{ +#define C(i) per_cpu(cpu_gdt_table, cpu)[GDT_ENTRY_TLS_MIN + i] = t->tls_array[i] + C(0); C(1); C(2); +#undef C +} + +static inline void clear_LDT(void) +{ + int cpu = get_cpu(); + + set_ldt_desc(cpu, &default_ldt[0], 5); + load_LDT_desc(); + put_cpu(); +} + +/* + * load one particular LDT into the current CPU + */ +static inline void load_LDT_nolock(mm_context_t *pc, int cpu) +{ + void *segments = pc->ldt; + int count = pc->size; + + if (likely(!count)) { + segments = &default_ldt[0]; + count = 5; + } + + set_ldt_desc(cpu, segments, count); + load_LDT_desc(); +} + +static inline void load_LDT(mm_context_t *pc) +{ + int cpu = get_cpu(); + load_LDT_nolock(pc, cpu); + put_cpu(); +} + +static inline unsigned long get_desc_base(unsigned long *desc) +{ + unsigned long base; + base = ((desc[0] >> 16) & 0x0000ffff) | + ((desc[1] << 16) & 0x00ff0000) | + (desc[1] & 0xff000000); + return base; +} + +#endif /* !__ASSEMBLY__ */ + +#endif |