/* 
 * 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_intr.h>
#include <palacios/vmm.h>

#include <palacios/vm_guest.h>

#ifndef DEBUG_INTERRUPTS
#undef PrintDebug
#define PrintDebug(fmt, args...)
#endif




void v3_init_interrupt_state(struct guest_info * info) {
  info->intr_state.excp_pending = 0;
  info->intr_state.excp_num = 0;
  info->intr_state.excp_error_code = 0;

  memset((uchar_t *)(info->intr_state.hooks), 0, sizeof(struct v3_irq_hook *) * 256);
}

void v3_set_intr_controller(struct guest_info * info, struct intr_ctrl_ops * ops, void * state) {
  info->intr_state.controller = ops;
  info->intr_state.controller_state = state;
}




static inline struct v3_irq_hook * get_irq_hook(struct guest_info * info, uint_t irq) {
  V3_ASSERT(irq <= 256);
  return info->intr_state.hooks[irq];
}


int v3_hook_irq(struct guest_info * info, 
		uint_t irq,
		int (*handler)(struct guest_info * info, struct v3_interrupt * intr, void * priv_data),
		void  * priv_data) 
{
  struct v3_irq_hook * hook = (struct v3_irq_hook *)V3_Malloc(sizeof(struct v3_irq_hook));

  if (hook == NULL) { 
    return -1; 
  }

  if (get_irq_hook(info, irq) != NULL) {
    PrintError("IRQ %d already hooked\n", irq);
    return -1;
  }

  hook->handler = handler;
  hook->priv_data = priv_data;
  
  info->intr_state.hooks[irq] = hook;

  if (V3_Hook_Interrupt(info, irq)) { 
    PrintError("hook_irq: failed to hook irq %d\n", irq);
    return -1;
  } else {
    PrintDebug("hook_irq: hooked irq %d\n", irq);
    return 0;
  }
}



static int passthrough_irq_handler(struct guest_info * info, struct v3_interrupt * intr, void * priv_data)
{

  PrintDebug("[passthrough_irq_handler] raise_irq=%d (guest=0x%p)\n", 
	     intr->irq, (void *)info);
  return v3_raise_irq(info, intr->irq);

}

int v3_hook_passthrough_irq(struct guest_info * info, uint_t irq)
{

  int rc = v3_hook_irq(info, 
		       irq,
		       passthrough_irq_handler,
		       NULL);

  if (rc) { 
    PrintError("guest_irq_injection: failed to hook irq 0x%x (guest=0x%p)\n", irq, (void *)info);
    return -1;
  } else {
    PrintDebug("guest_irq_injection: hooked irq 0x%x (guest=0x%p)\n", irq, (void *)info);
    return 0;
  }
}





int v3_deliver_irq(struct guest_info * info, struct v3_interrupt * intr) {
  PrintDebug("v3_deliver_irq: irq=%d state=0x%p, \n", intr->irq, (void *)intr);
  
  struct v3_irq_hook * hook = get_irq_hook(info, intr->irq);

  if (hook == NULL) {
    PrintError("Attempting to deliver interrupt to non registered hook(irq=%d)\n", intr->irq);
    return -1;
  }
  
  return hook->handler(info, intr, hook->priv_data);
}








int v3_raise_exception_with_error(struct guest_info * info, uint_t excp, uint_t error_code) {
  struct v3_intr_state * intr_state = &(info->intr_state);

  if (intr_state->excp_pending == 0) {
    intr_state->excp_pending = 1;
    intr_state->excp_num = excp;
    intr_state->excp_error_code = error_code;
    intr_state->excp_error_code_valid = 1;
    PrintDebug("[v3_raise_exception_with_error] error code: %x\n", error_code);
  } else {
    PrintError("exception already pending, currently not implemented\n");
    return -1;
  }

  return 0;
}

int v3_raise_exception(struct guest_info * info, uint_t excp) {
  struct v3_intr_state * intr_state = &(info->intr_state);
  PrintDebug("[v3_raise_exception]\n");
  if (intr_state->excp_pending == 0) {
    intr_state->excp_pending = 1;
    intr_state->excp_num = excp;
    intr_state->excp_error_code = 0;
    intr_state->excp_error_code_valid = 0;
  } else {
    PrintError("exception already pending, currently not implemented\n");
    return -1;
  }

  return 0;
}


int v3_lower_irq(struct guest_info * info, int irq) {
  // Look up PIC and resend
  V3_ASSERT(info);
  V3_ASSERT(info->intr_state.controller);
  V3_ASSERT(info->intr_state.controller->lower_intr);

  PrintDebug("[v3_lower_irq]\n");

  if ((info->intr_state.controller) && 
      (info->intr_state.controller->lower_intr)) {
    info->intr_state.controller->lower_intr(info->intr_state.controller_state, irq);
  } else {
    PrintError("There is no registered Interrupt Controller... (NULL POINTER)\n");
    return -1;
  }

  return 0;
}

int v3_raise_irq(struct guest_info * info, int irq) {
  // Look up PIC and resend
  V3_ASSERT(info);
  V3_ASSERT(info->intr_state.controller);
  V3_ASSERT(info->intr_state.controller->raise_intr);

  PrintDebug("[v3_raise_irq]\n");

  if ((info->intr_state.controller) && 
      (info->intr_state.controller->raise_intr)) {
    info->intr_state.controller->raise_intr(info->intr_state.controller_state, irq);
  } else {
    PrintError("There is no registered Interrupt Controller... (NULL POINTER)\n");
    return -1;
  }

  return 0;
}



int v3_intr_pending(struct guest_info * info) {
  struct v3_intr_state * intr_state = &(info->intr_state);

  //  PrintDebug("[intr_pending]\n");
  if (intr_state->excp_pending == 1) {
    return 1;
  } else if (intr_state->controller->intr_pending(intr_state->controller_state) == 1) {
    return 1;
  }

  /* Check [A]PIC */

  return 0;
}


uint_t v3_get_intr_number(struct guest_info * info) {
  struct v3_intr_state * intr_state = &(info->intr_state);

  if (intr_state->excp_pending == 1) {
    return intr_state->excp_num;
  } else if (intr_state->controller->intr_pending(intr_state->controller_state)) {
    PrintDebug("[get_intr_number] intr_number = %d\n", intr_state->controller->get_intr_number(intr_state->controller_state));
    return intr_state->controller->get_intr_number(intr_state->controller_state);
  }

  /* someway to get the [A]PIC intr */

  return 0;
}


intr_type_t v3_get_intr_type(struct guest_info * info) {
  struct v3_intr_state * intr_state = &(info->intr_state);

  if (intr_state->excp_pending) {
    PrintDebug("[get_intr_type] Exception\n");
    return EXCEPTION;
  } else if (intr_state->controller->intr_pending(intr_state->controller_state)) {
    PrintDebug("[get_intr_type] External_irq\n");
    return EXTERNAL_IRQ;
  }
    PrintDebug("[get_intr_type] Invalid_Intr\n");
  return INVALID_INTR;
}






int v3_injecting_intr(struct guest_info * info, uint_t intr_num, intr_type_t type) {
  struct v3_intr_state * intr_state = &(info->intr_state);

  if (type == EXCEPTION) {
    PrintDebug("[injecting_intr] Exception\n");
    intr_state->excp_pending = 0;
    intr_state->excp_num = 0;
    intr_state->excp_error_code = 0;
    intr_state->excp_error_code_valid = 0;
    
  } else if (type == EXTERNAL_IRQ) {
    PrintDebug("[injecting_intr] External_Irq with intr_num = %x\n", intr_num);
    return intr_state->controller->begin_irq(intr_state->controller_state, intr_num);
  }

  return 0;
}