#include "kernel.h"
// http://www.intel.com/content/dam/doc/specification-update/64-architecture-x2apic-specification.pdf
// http://download.intel.com/design/chipsets/datashts/29056601.pdf
// http://www.scs.stanford.edu/05au-cs240c/lab/ia32/IA32-3.pdf
// https://wiki.osdev.org/Symmetric_Multiprocessing
// https://wiki.osdev.org/APIC_timer

#include <stdint.h>
#include "smp.h"
#include "mem.h"
#include "spinlock.h"
#include "asm_x86.h"

#define FOOLOS_APIC_SPUR_INT 0x00f0
#define FOOLOS_APIC_INT_COMMAND_LOW 0x0300
#define FOOLOS_APIC_INT_COMMAND_HIGH 0x0310
#define FOOLOS_APIC_ID 0x020

#define APIC_APICID	0x20
#define APIC_APICVER	0x30
#define APIC_TASKPRIOR	0x80
#define APIC_EOI	0x0B0
#define APIC_LDR	0x0D0
#define APIC_DFR	0x0E0
#define APIC_SPURIOUS	0x0F0
#define APIC_ESR	0x280
#define APIC_ICRL	0x300
#define APIC_ICRH	0x310
#define APIC_LVT_TMR	0x320
#define APIC_LVT_PERF	0x340
#define APIC_LVT_LINT0	0x350
#define APIC_LVT_LINT1	0x360
#define APIC_LVT_ERR	0x370
#define APIC_TMRINITCNT	0x380
#define APIC_TMRCURRCNT	0x390
#define APIC_TMRDIV	0x3E0
#define APIC_LAST	0x38F
#define APIC_DISABLE	0x10000
#define APIC_SW_ENABLE	0x100
#define APIC_CPUFOCUS	0x200
#define APIC_NMI	(4<<8)
#define TMR_PERIODIC	0x20000
#define TMR_BASEDIV	(1<<20)

// some multiprocessor shit that should move away TODO
uint32_t c1,c2,c3;
volatile uint8_t proc;
uint32_t cpu_counter[SMP_MAX_PROC];

uint32_t local_apic_addr;
extern uint32_t LLOCK;

void smp_main()
{
    // setup stack
    uint32_t ebp=kballoc(1);
    asm volatile("mov %0, %%ebp"::"r"(ebp));
    asm volatile("mov %ebp, %esp");
    asm volatile("jmp kernel_ap");
}

void writeAPIC(uint32_t offset, uint32_t value)
{
    uint32_t *reg;
    reg=local_apic_addr+offset;
    *reg=value;
}

uint32_t readAPIC(uint32_t offset)
{
    uint32_t *reg;
    reg=local_apic_addr+offset;
    uint32_t value=*reg;
    return value;
}

void kernel_ap()
{

    uint32_t *reg;
    reg=local_apic_addr+FOOLOS_APIC_ID;
    klog("smp local apic id: 0x%08X",(*reg));

    reg=local_apic_addr+FOOLOS_APIC_SPUR_INT;
    klog("svr value: 0x%08X",(*reg));
    *reg|=0x100; // enable APIC

    int_install();
    gdt_init();

    uint32_t countdown=0x0fffffff;
    writeAPIC(APIC_TMRDIV, 0x3);
    writeAPIC(APIC_LVT_TMR, 200 | TMR_PERIODIC);
    writeAPIC(APIC_TMRINITCNT, countdown);
   

    x86_sti();
    LLOCK=0; // release lock, so next ap can continue...

    while(1)
    {
	asm("hlt");
	klog("tack: 0x%08X: 0x%08X",readAPIC(FOOLOS_APIC_ID), readAPIC(APIC_TMRCURRCNT));
   }

//    switch_to_user_mode();
    /*

    while(1);

    uint32_t ebp=pmmngr_alloc_block()+4095;

    asm volatile("mov %0, %%ebp"::"r"(ebp));
    asm volatile("mov %ebp, %esp");
    asm volatile("jmp kernel_ap");

    proc=c1=c2=c3=0;
    for(int i=0;i<SMP_MAX_PROC;i++)cpu_counter[i]=0;
    */
}


void kernel_ap_old()
{
	proc++;
	uint8_t p=proc;
	while(1)
	{
	    cpu_counter[p]++;

 	    //lock_spin(0);
	    if(cpu_counter[p]%1000000==0)klog("cpu[%d] %d",p,cpu_counter[p]);
	    //lock_release(0);

	}
}

void smp_log_procdata(smp_processors *procdata)
{
    klog("---- smp -----");
    for(int i=0;i<procdata->processors;i++)
    {
	klog("cpu %d, apic_id: 0x%X, bps: %s, apic_addr:0x%08X",i,procdata->local_apic_id[i],i==procdata->boot?"yes":"no",procdata->local_apic_address);
    }

}

// this will start all our application processors!
void smp_start_aps(smp_processors *pros)
{

    // TODO: check if local APIC is present via CPUID (P6 (i686) and above)
	local_apic_addr=pros->local_apic_address;

	//bsp (boot processor) enables its local apic
//	uint32_t *reg=local_apic_addr+FOOLOS_APIC_SPUR_INT;
//	*reg=0xffffffff; // all bits 1 and interrupt 255 (is this not set anyway?)
//	*reg=0;

        uint32_t *reg=local_apic_addr+FOOLOS_APIC_ID;
	klog("bsp local apic id: 0x%08X",(*reg));

        for(int i=0;i<pros->processors;i++)
	{
	    if(pros->boot==i)continue;

	    uint8_t dest=pros->local_apic_id[i];
	    klog("starting cpu %d (dest: %d) ",i,dest);

	    reg=local_apic_addr+FOOLOS_APIC_INT_COMMAND_HIGH;
	    *reg=dest<<24; // destination apic.

	    reg=local_apic_addr+FOOLOS_APIC_INT_COMMAND_LOW;
	    *reg=(5<<8)|(1<<14); // 101 INIT

	    // do we really neet this?
	    // TODO!!
	    // todo: use some real sleep (not implemented yet :( )
	    //sleep(30);

	    // start proc 0x7 = at addr 0x7000;
	    *reg=(6<<8)|(1<<14)|0x7; // 110 SIPI
	}
}