/* 
 * This file is part of the Palacios Virtual Machine Monitor developed
 * by the V3VEE Project with funding from the United States National 
 * Science Foundation and the Department of Energy.  
 *
 * The V3VEE Project is a joint project between Northwestern University
 * and the University of New Mexico.  You can find out more at 
 * http://www.v3vee.org
 *
 * Copyright (c) 2008, Jack Lange <jarusl@cs.northwestern.edu>
 * Copyright (c) 2008, The V3VEE Project <http://www.v3vee.org> 
 * All rights reserved.
 *
 * Author: Jack Lange <jarusl@cs.northwestern.edu>
 *
 * This is free software.  You are permitted to use,
 * redistribute, and modify it as specified in the file "V3VEE_LICENSE".
 */

#include <palacios/vmm.h>
#include <palacios/vmm_dev_mgr.h>
#include <palacios/vmm_sym_swap.h>
#include <palacios/vm_guest.h>



void __udelay(unsigned long usecs);


struct disk_state {
    struct v3_dev_blk_ops * ops;
    uint32_t seek_usecs;

    void * private_data;
};


static int model_write(uint8_t * buf,  uint64_t lba, uint64_t num_bytes, void * private_data) {
    struct disk_state * model = (struct disk_state *)private_data;
    
    __udelay(model->seek_usecs);

    return model->ops->write(buf, lba, num_bytes, model->private_data);

}

static int model_read(uint8_t * buf,  uint64_t lba, uint64_t num_bytes, void * private_data) {
    struct disk_state * model = (struct disk_state *)private_data;
    
    __udelay(model->seek_usecs);

    return model->ops->read(buf, lba, num_bytes, model->private_data);

}

static uint64_t model_get_capacity(void * private_data) {
    struct disk_state * model = (struct disk_state *)private_data;

    return model->ops->get_capacity(model->private_data);
}

static int model_free(struct vm_device * dev) {
    return -1;
}



static struct v3_dev_blk_ops blk_ops = {
    .read = model_read, 
    .write = model_write, 
    .get_capacity = model_get_capacity,
};



static struct v3_device_ops dev_ops = {
    .free = model_free,
    .reset = NULL,
    .start = NULL,
    .stop = NULL,
};


static int connect_fn(struct guest_info * info, 
		      void * frontend_data, 
		      struct v3_dev_blk_ops * ops, 
		      v3_cfg_tree_t * cfg, 
		      void * private_data) {

  v3_cfg_tree_t * frontend_cfg = v3_cfg_subtree(cfg, "frontend");
  uint32_t seek_time = atoi(v3_cfg_val(cfg, "seek_us"));
  struct disk_state * model = (struct disk_state *)V3_Malloc(sizeof(struct disk_state));


  model->ops = ops;
  model->seek_usecs = seek_time;
  model->private_data = private_data;

  if (v3_dev_connect_blk(info, v3_cfg_val(frontend_cfg, "tag"), 
			 &blk_ops, frontend_cfg, model) == -1) {
      PrintError("Could not connect  to frontend %s\n", 
		  v3_cfg_val(frontend_cfg, "tag"));
      return -1;
  }

  return 0;
}

static int model_init(struct guest_info * vm, v3_cfg_tree_t * cfg) {

    char * name = v3_cfg_val(cfg, "name");

    struct vm_device * dev = v3_allocate_device(name, &dev_ops, NULL);

    if (v3_attach_device(vm, dev) == -1) {
	PrintError("Could not attach device %s\n", name);
	return -1;
    }

    if (v3_dev_add_blk_frontend(vm, name, connect_fn, NULL) == -1) {
	PrintError("Could not register %s as block frontend\n", name);
	return -1;
    }


    return 0;
}



device_register("DISK_MODEL", model_init)