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#ifndef __ARCH_DESC_H
#define __ARCH_DESC_H

#include <asm/ldt.h>
#include <asm/segment.h>

#ifndef __ASSEMBLY__

#include <linux/preempt.h>
#include <linux/smp.h>

#include <asm/mmu.h>

extern struct desc_struct cpu_gdt_table[NR_CPUS][GDT_ENTRIES];

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(&cpu_gdt_table[cpu][entry], (int)addr, 235, 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(&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) 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();
}

#endif /* !__ASSEMBLY__ */

#endif