/* 
 * 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>
#include <palacios/vmm_ctrl_regs.h>

#include <palacios/vmm_lock.h>

#ifndef V3_CONFIG_DEBUG_INTERRUPTS
#undef PrintDebug
#define PrintDebug(fmt, args...)
#endif




struct intr_controller {
    struct intr_ctrl_ops * ctrl_ops;
    
    void * priv_data;
    struct list_head ctrl_node;
};


struct intr_router {
    struct intr_router_ops * router_ops;

    void * priv_data;
    struct list_head router_node;

};

void v3_init_intr_controllers(struct guest_info * info) {
    struct v3_intr_core_state * intr_state = &(info->intr_core_state);

    intr_state->irq_pending = 0;
    intr_state->irq_started = 0;
    intr_state->irq_vector = 0;

    v3_lock_init(&(intr_state->irq_lock));

    INIT_LIST_HEAD(&(intr_state->controller_list));
}


void v3_deinit_intr_controllers(struct guest_info * core) {
    struct v3_intr_core_state * intr_state = &(core->intr_core_state);
    struct intr_controller * ctrlr;
    struct intr_controller * tmp;

    // clear out any controllers that were left around
    if (*(void**)&intr_state->controller_list) {
        list_for_each_entry_safe(ctrlr, tmp, &(intr_state->controller_list), ctrl_node) {
        v3_remove_intr_controller(core, ctrlr);
        }

        v3_lock_deinit(&(intr_state->irq_lock));
    }

}


void v3_init_intr_routers(struct v3_vm_info * vm) {
    
    INIT_LIST_HEAD(&(vm->intr_routers.router_list));
    
    v3_lock_init(&(vm->intr_routers.irq_lock));

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


void v3_deinit_intr_routers(struct v3_vm_info * vm) {
    struct intr_router * rtr = NULL;
    struct intr_router * tmp = NULL;

    // clear out any routers that were left around
    if (*(void**)&vm->intr_routers.router_list) {
        list_for_each_entry_safe(rtr, tmp, &(vm->intr_routers.router_list), router_node) {
        v3_remove_intr_router(vm, rtr);
        }  

        v3_lock_deinit(&(vm->intr_routers.irq_lock));
    }
}

void * v3_register_intr_controller(struct guest_info * info, struct intr_ctrl_ops * ops, void * priv_data) {
    struct intr_controller * ctrlr = (struct intr_controller *)V3_Malloc(sizeof(struct intr_controller));

    if (!ctrlr) {
	PrintError(info->vm_info, info, "Cannot allocate in registering an interrupt controller\n");
	return NULL;
    }

    ctrlr->priv_data = priv_data;
    ctrlr->ctrl_ops = ops;

    list_add(&(ctrlr->ctrl_node), &(info->intr_core_state.controller_list));
    
    return (void *)ctrlr;
}

void v3_remove_intr_controller(struct guest_info * core, void * handle) {
    struct v3_intr_core_state * intr_state = &(core->intr_core_state);
    struct intr_controller * ctrlr = handle;
    struct intr_controller * tmp = NULL;
    int found = 0;

    // search for the entry in the router list
    list_for_each_entry(tmp, &(intr_state->controller_list), ctrl_node) {
	if (tmp == ctrlr) {
	    found = 1;
	}
    }

    if (found == 0) {
	PrintError(core->vm_info, core, "Attempted to remove invalid interrupt controller handle\n");
	return;
    }

    list_del(&(ctrlr->ctrl_node));
    V3_Free(ctrlr);
}

void * v3_register_intr_router(struct v3_vm_info * vm, struct intr_router_ops * ops, void * priv_data) {
    struct intr_router * router = (struct intr_router *)V3_Malloc(sizeof(struct intr_router));

    if (!router) {
        PrintError(vm, VCORE_NONE,"Cannot allocate in registering an interrupt router\n");
	return NULL;
    }

    router->priv_data = priv_data;
    router->router_ops = ops;

    list_add(&(router->router_node), &(vm->intr_routers.router_list));
    
    return (void *)router;
}

void v3_remove_intr_router(struct v3_vm_info * vm, void * handle) {
    struct intr_router * router = handle;
    struct intr_router * tmp = NULL;
    int found = 0;

    // search for the entry in the router list
    list_for_each_entry(tmp, &(vm->intr_routers.router_list), router_node) {
	if (tmp == router) {
	    found = 1;
	}
    }

    if (found == 0) {
        PrintError(vm, VCORE_NONE, "Attempted to remove invalid interrupt router\n");
	return;
    }

    list_del(&(router->router_node));
    V3_Free(router);
}



static inline struct v3_irq_hook * get_irq_hook(struct v3_vm_info * vm, uint_t irq) {
    V3_ASSERT(vm, VCORE_NONE,irq <= 256);
    return vm->intr_routers.hooks[irq];
}


int v3_hook_irq(struct v3_vm_info * vm,
		uint_t irq,
		int (*handler)(struct v3_vm_info * vm, 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) { 
	PrintError(vm, VCORE_NONE, "Cannot allocate when hooking an irq\n");
	return -1; 
    }

    if (get_irq_hook(vm, irq) != NULL) {
	PrintError(vm, VCORE_NONE, "IRQ %d already hooked\n", irq);
	V3_Free(hook);
	return -1;
    }

    hook->handler = handler;
    hook->priv_data = priv_data;
  
    vm->intr_routers.hooks[irq] = hook;

    if (V3_Hook_Interrupt(vm, irq)) { 
	PrintError(vm, VCORE_NONE, "hook_irq: failed to hook irq %d\n", irq);
	vm->intr_routers.hooks[irq] = NULL;
	V3_Free(hook);
	return -1;
    } else {
        PrintDebug(vm, VCORE_NONE, "hook_irq: hooked irq %d\n", irq);
	return 0;
    }
}



static int passthrough_irq_handler(struct v3_vm_info * vm, struct v3_interrupt * intr, void * priv_data) {
    PrintDebug(vm, VCORE_NONE, "[passthrough_irq_handler] raise_irq=%d (guest=0x%p)\n", 
	       intr->irq, (void *)vm);

    return v3_raise_irq(vm, intr->irq);
}

int v3_hook_passthrough_irq(struct v3_vm_info * vm, uint_t irq) {
    int rc = v3_hook_irq(vm, irq, passthrough_irq_handler, NULL);

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





int v3_deliver_irq(struct v3_vm_info * vm, struct v3_interrupt * intr) {
    PrintDebug(vm, VCORE_NONE, "v3_deliver_irq: irq=%d state=0x%p, \n", intr->irq, (void *)intr);
  
    struct v3_irq_hook * hook = get_irq_hook(vm, intr->irq);

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




int v3_raise_swintr (struct guest_info * core, uint8_t vector) {
    struct v3_intr_core_state * intr_state = &(core->intr_core_state);

    PrintDebug(core->vm_info, core, "Signaling software interrupt in v3_signal_swintr()\n");
    PrintDebug(core->vm_info, core, "\tINT vector: %d\n", vector);
    
    intr_state->swintr_posted = 1;
    intr_state->swintr_vector = vector;
    return 0;
}



int v3_raise_virq(struct guest_info * info, int irq) {
    struct v3_intr_core_state * intr_state = &(info->intr_core_state);
    int major = irq / 8;
    int minor = irq % 8;

    intr_state->virq_map[major] |= (1 << minor);
   
    return 0;
}

int v3_lower_virq(struct guest_info * info, int irq) {
    struct v3_intr_core_state * intr_state = &(info->intr_core_state);
    int major = irq / 8;
    int minor = irq % 8;

    intr_state->virq_map[major] &= ~(1 << minor);

    return 0;
}


int v3_lower_irq(struct v3_vm_info * vm, int irq) {
    struct v3_irq irq_state;

    irq_state.irq = irq;
    irq_state.ack = NULL;
    irq_state.private_data = NULL;

    return v3_lower_acked_irq(vm, irq_state);
}

int v3_raise_irq(struct v3_vm_info * vm, int irq) {
    struct v3_irq irq_state;

    irq_state.irq = irq;
    irq_state.ack = NULL;
    irq_state.private_data = NULL;

    return v3_raise_acked_irq(vm, irq_state);
}


int v3_raise_acked_irq(struct v3_vm_info * vm, struct v3_irq irq) {
    struct intr_router * router = NULL;
    struct v3_intr_routers * routers = &(vm->intr_routers);

    //  PrintDebug(info->vm_info, info, "[v3_raise_irq (%d)]\n", irq);
    addr_t irq_state = v3_lock_irqsave(routers->irq_lock);

    list_for_each_entry(router, &(routers->router_list), router_node) {
	router->router_ops->raise_intr(vm, router->priv_data, &irq);
    }

    v3_unlock_irqrestore(routers->irq_lock, irq_state);

    return 0;
}


int v3_lower_acked_irq(struct v3_vm_info * vm, struct v3_irq irq) {
    struct intr_router * router = NULL;
    struct v3_intr_routers * routers = &(vm->intr_routers);

    //    PrintDebug(info->vm_info, info, "[v3_lower_irq]\n");
    addr_t irq_state = v3_lock_irqsave(routers->irq_lock);

    list_for_each_entry(router, &(routers->router_list), router_node) {
	router->router_ops->lower_intr(vm, router->priv_data, &irq);
    }
 
    v3_unlock_irqrestore(routers->irq_lock, irq_state);

    return 0;

}



void v3_clear_pending_intr(struct guest_info * core) {
    struct v3_intr_core_state * intr_state = &(core->intr_core_state);

    intr_state->irq_pending = 0;

}


v3_intr_type_t v3_intr_pending(struct guest_info * info) {
    struct v3_intr_core_state * intr_state = &(info->intr_core_state);
    struct intr_controller * ctrl = NULL;
    int ret = V3_INVALID_INTR;
    int i = 0;

    //  PrintDebug(info->vm_info, info, "[intr_pending]\n");
    addr_t irq_state = v3_lock_irqsave(intr_state->irq_lock);

    // External IRQs have lowest priority
    list_for_each_entry(ctrl, &(intr_state->controller_list), ctrl_node) {
	if (ctrl->ctrl_ops->intr_pending(info, ctrl->priv_data)) {
	    ret = V3_EXTERNAL_IRQ;
	    break;
	}
    }   

    // VIRQs have 2nd priority
    for (i = 0; i < MAX_IRQ / 8; i++) {
	if (intr_state->virq_map[i] != 0) {   
	    ret = V3_VIRTUAL_IRQ;
	    break;
	}
    }

    /* SWINTRs have highest */
    if (intr_state->swintr_posted == 1) {
        ret = V3_SOFTWARE_INTR;
    }

    v3_unlock_irqrestore(intr_state->irq_lock, irq_state);

    return ret;
}


int v3_get_intr(struct guest_info * info) {
    struct v3_intr_core_state * intr_state = &(info->intr_core_state);
    struct intr_controller * ctrl = NULL;
    int ret = -1;
    int i = 0;
    int j = 0;
    int found_virq=0;
    int found_irq=0;

    addr_t irq_state = v3_lock_irqsave(intr_state->irq_lock);    

    // virqs have priority
    for (i = 0; i < MAX_IRQ / 8; i++) {
	if (intr_state->virq_map[i] != 0) {
	    for (j = 0; j < 8; j++) {
		if (intr_state->virq_map[i] & (1 << j)) {
		    ret = (i * 8) + j;
		    // need to be able to find virq 0
		    found_virq=1;
		    break;
		}
	    }
	    break;
	}
    }

    if (!found_virq) {
	list_for_each_entry(ctrl, &(intr_state->controller_list), ctrl_node) {
	    if (ctrl->ctrl_ops->intr_pending(info, ctrl->priv_data)) {
		int intr_num = ctrl->ctrl_ops->get_intr_number(info, ctrl->priv_data);
		
		if (intr_num >= 0) {
		  //	PrintDebug(info->vm_info, info, "[get_intr_number] intr_number = %d\n", intr_num);
		  ret = intr_num;
		  found_irq=1;
		  break;
		}

	    }
	}
    }

    v3_unlock_irqrestore(intr_state->irq_lock, irq_state);

    if (!found_virq && !found_irq) { 
      PrintError(info->vm_info,info,"Strange... neither a VIRQ nor an IRQ was found...\n");
    }

    return ret;
}

/*
intr_type_t v3_get_intr_type(struct guest_info * info) {
    struct v3_intr_state * intr_state = &(info->intr_state);
    struct intr_controller * ctrl = NULL;
    intr_type_t type = V3_INVALID_INTR;

    addr_t irq_state = v3_lock_irqsave(intr_state->irq_lock);  

    list_for_each_entry(ctrl, &(intr_state->controller_list), ctrl_node) {
	if (ctrl->ctrl_ops->intr_pending(ctrl->priv_data) == 1) {
	    //PrintDebug(info->vm_info, info, "[get_intr_type] External_irq\n");
	    type = V3_EXTERNAL_IRQ;	    
	    break;
	}
    }

#ifdef V3_CONFIG_DEBUG_INTERRUPTS
    if (type == V3_INVALID_INTR) {
	PrintError(info->vm_info, info, "[get_intr_type] Invalid_Intr\n");
    }
#endif

    v3_unlock_irqrestore(intr_state->irq_lock, irq_state);

    return type;
}
*/





int v3_injecting_intr(struct guest_info * info, uint_t intr_num, v3_intr_type_t type) {
    struct v3_intr_core_state * intr_state = &(info->intr_core_state);

    if (type == V3_EXTERNAL_IRQ) {
	struct intr_controller * ctrl = NULL;

	addr_t irq_state = v3_lock_irqsave(intr_state->irq_lock); 

	//	PrintDebug(info->vm_info, info, "[injecting_intr] External_Irq with intr_num = %x\n", intr_num);
	list_for_each_entry(ctrl, &(intr_state->controller_list), ctrl_node) {
	    ctrl->ctrl_ops->begin_irq(info, ctrl->priv_data, intr_num);
	}

	v3_unlock_irqrestore(intr_state->irq_lock, irq_state);
    }

    return 0;
}