#include "device/processor.h"
#include "arch/x86_64/tables.h"
#include "include/arch/x86_64/idt.h"
#include "include/arch/x86_64/object.h"
#include "jove.h"

processor_t s_bsp = {
    .odir = &_initDirectory
};

struct jove_ObjectDirectory s_processor_dir = {
    .entries = { 
        [0] = {
            .type = KO_OBJECT_DIRECTORY,
            .data = 2
        }, 
        [1] = {
            .type = KO_DEV_PROCESSOR,
            .data = (uintptr_t)&s_bsp
        }
    }
};

char s_initial_response_buffer[256] = { 0 };

typedef union msr_efer
{
    struct {
        uint8_t sce : 1;
        uint8_t resv : 7;
        uint8_t lme : 1;
        uint8_t unk0 : 1;
        uint8_t lma : 1;
        uint8_t nxe : 1;
        uint8_t svme : 1;
        uint8_t lmsle : 1;
        uint8_t ffxsr : 1;
        uint8_t tce : 1;
    };
    uint32_t v[2];
} msr_efer_t;

typedef union msr_star
{
    struct {
        uint32_t eip;
        uint16_t kcs;
        uint16_t ucs;
    };
    uint32_t v[2];
} msr_star_t;

typedef union msr_lstar
{
    uint32_t v[2];
    uintptr_t ip;
} msr_lstar_t;

static void
s_enable_sce(void)
{
    msr_efer_t feat;
    rdmsr(MSR_EFER, &feat.v[0], &feat.v[1]);

    feat.sce = 1;
    wrmsr(MSR_EFER, feat.v[0], feat.v[1]);

    msr_star_t star;
    star.kcs = GDT_ENTRY_KERNEL_CODE * sizeof(segment_descriptor_t);
    star.ucs = GDT_ENTRY_USER_CODE * sizeof(segment_descriptor_t);
    wrmsr(MSR_STAR, star.v[0], star.v[1]);

    extern void _syscall_entry(void);
    msr_lstar_t lstar;
    lstar.ip = (uintptr_t)_syscall_entry;
    wrmsr(MSR_LSTAR, lstar.v[0], lstar.v[1]);
}

void
processor_setup(void *_processor)
{
    processor_t *processor = (processor_t*)_processor;
    gdt_setup(processor);
    idt_setup(processor);

    wrmsr(MSR_GS_BASE, 
            (uint32_t)((uintptr_t)_processor & 0xFFFFFFFF),
    (uint32_t)((uintptr_t)_processor >> 32));
}

void enable_fpu(void);
void enable_sse(void);
void enable_avx(void);

void
bsp_setup(void)
{
#ifdef ENABLE_SSE
    enable_fpu();
    enable_sse();
#endif
#ifdef ENABLE_AVX
    enable_avx();
#endif

    _initDirectory.entries[INIT_OBJECT_PROCESSOR_DIR] = (objdir_entry_t) {
        .type = KO_OBJECT_DIRECTORY,
        .data = (uintptr_t)(&s_processor_dir)
    };

    ivt_setup();
    s_enable_sce();

    processor_setup(&s_bsp);
}

void 
rdmsr(uint32_t msr, uint32_t *lo, uint32_t *hi)
{
    __asm__ volatile("rdmsr": "=a"(*lo), "=d"(*hi): "c"(msr));
}

void
wrmsr(uint32_t msr, uint32_t lo, uint32_t hi)
{
    __asm__ volatile("wrmsr":: "a"(lo), "d"(hi), "c"(msr));
}

void*
processor_current(void)
{
    uint64_t r = 0;
    rdmsr(MSR_GS_BASE, (uint32_t*)&r, ((uint32_t*)&r) + 1);
    return (void*)r;
}