// The OS/K Team licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.

#include <pc/dev.h>

//----------------------------------------------------------------------------//

#define MAX_RFRAME_IDX 255

//
// Register frames
//
reg_t **rfs = NULL;

size_t current_idx = 0;
size_t rfs_used = 0;

#define CHK_INDEX(idx)                                                      \
    if ((ulong)idx > MAX_RFRAME_IDX)                                        \
        _except(ctx, E_UDF, "cpudev: invalid rframe index: #%u", idx);

//----------------------------------------------------------------------------//

long cpudev_getmaxidx(ctx_t *ctx, dev_t *dev)
{
    rax = MAX_RFRAME_IDX;
    return 0;
}

long cpudev_getrfusage(ctx_t *ctx, dev_t *dev)
{
    rax = rfs_used;
    return 0;
}

long cpudev_getcuridx(ctx_t *ctx, dev_t *dev)
{
    rax = current_idx;
    return 0;
}

long cpudev_leastavail(ctx_t *ctx, dev_t *dev)
{
    size_t it;

    for (it = 0; it <= MAX_RFRAME_IDX; it++)
    {
        if (rfs[it] == NULL)
        {
            rax = it;
            return 0;
        }
    }

    rax = -1;
    return 0;
}

//----------------------------------------------------------------------------//

long cpudev_isactive(ctx_t *ctx, dev_t *dev)
{
    CHK_INDEX(ax0);

    rax = (rfs[ax0] != NULL);

    return 0;
}

long cpudev_activate(ctx_t *ctx, dev_t *dev)
{
    CHK_INDEX(ax0);
    
    if (rfs[ax0] != NULL)
        _except(ctx, E_UDF,
            "cpudev: activating already activated rframe: #%u", ax0);

    return 0;
}

long cpudev_deactivate(ctx_t *ctx, dev_t *dev)
{
    CHK_INDEX(ax0);
    
    if (ax0 == 0)
        _except(ctx, E_UDF, "cpudev: deactivating rframe #0 (arch_r)");

    return 0;
}

//----------------------------------------------------------------------------//

//----------------------------------------------------------------------------//

long cpudev_poweron(ctx_t *ctx, dev_t *dev)
{
    rfs = calloc(MAX_RFRAME_IDX + 2, sizeof(reg_t *));
    
    if (rfs == NULL)
        return -1;

    rfs[0] = ctx->r;
    rfs_used = 1;

    dev->state = DEVGOOD;
    
    dev->fslots[16] = cpudev_getmaxidx;
    dev->fslots[17] = cpudev_getrfusage;
    dev->fslots[18] = cpudev_getcuridx;
    dev->fslots[19] = cpudev_leastavail;
    dev->fslots[20] = cpudev_isactive;
    dev->fslots[21] = cpudev_activate;
    dev->fslots[22] = cpudev_deactivate;

    return 0;
}

long cpudev_poweroff(ctx_t *ctx, dev_t *dev)
{
    if (rfs)
        free(rfs);

    return 0;
}

//----------------------------------------------------------------------------//

dev_t cpudev =
{
    .type = "cpu",
    .name = "K-CPU",
    .modl = "Prisma 1",
    .vend = "The OS/K Team",

    .major = KARCH_MAJOR,
    .minor = KARCH_MINOR,
    .revis = KARCH_REVIS,

    .fpwon = cpudev_poweron,
};