//
// File:  src/root/pager.cc
//
// Description: trivial pager loop for root threads
//
#include <config.h>

#include <l4/message.h>
#include <l4/ipc.h>
#include <l4/thread.h>
#include <l4/sigma0.h>

#include <sdi/panic.h>
#include <sdi/util.h>

#include <stdio.h>
#include <stdlib.h>

#include "root.h"

void pager_loop()
{
	L4_ThreadId_t tid;
	L4_MsgTag_t tag;
	L4_Msg_t msg;
 
	L4_Word_t page_bits = lsBit(L4_PageSizeMask((L4_KernelInterfacePage_t*)L4_KernelInterface ()));
   
	while(true)
	{
		tag = L4_Wait(&tid);
		
		while(true)
		{
			L4_Store(tag, &msg);
		
#if 0
			printf ("Root-Pager got msg from %p (%p, %p, %p)\n",
				(void *) tid.raw, (void *) tag.raw,
				(void *) L4_Get (&msg, 0), (void *) L4_Get (&msg, 1));
#endif

			if (L4_UntypedWords (tag) != 2 || L4_TypedWords (tag) != 0 ||
				!L4_IpcSucceeded (tag))
			{
				printf("malformed pagefault IPC from %p (tag=%p)\n",
					   (void *) tid.raw, (void *) tag.raw);
				panic("malformed pagefault in root");
				break;
			}
	
			L4_Word_t faddr = L4_Get (&msg, 0);
			/* L4_Word_t fip   = L4_Get (&msg, 1); */
		
			/* This is really ugly, we just touch this address to bring 
			   the page into our address space */
			volatile char* dummy = (char*)faddr;
			*dummy;
		
			/* Send mapitem, note that this is a nop between threads in the 
			   the same address space */
			L4_Clear(&msg);
			L4_Append(&msg, L4_MapItem(L4_FpageLog2(faddr, page_bits) +
									   L4_FullyAccessible, faddr));
			L4_Load(&msg);
		
			L4_ThreadId_t nextid = L4_nilthread;
			tag = L4_ReplyWait(tid, &nextid);
			tid = nextid;
		}
	}
}