/* The kernel call implemented in this file:
 *   m_type:	SYS_VMCTL
 *
 * The parameters for this kernel call are:
 *   	SVMCTL_WHO	which process
 *    	SVMCTL_PARAM	set this setting (VMCTL_*)
 *    	SVMCTL_VALUE	to this value
 */

#include "../system.h"
#include "../vm.h"
#include "../debug.h"
#include <minix/type.h>

/*===========================================================================*
 *				do_vmctl				     *
 *===========================================================================*/
PUBLIC int do_vmctl(struct proc * caller, message * m_ptr)
{
  int proc_nr;
  endpoint_t ep = m_ptr->SVMCTL_WHO;
  struct proc *p, *rp, *target;
  int err;

  if(ep == SELF) { ep = m_ptr->m_source; }

  if(!isokendpt(ep, &proc_nr)) {
	kprintf("do_vmctl: unexpected endpoint %d from VM\n", ep);
	return EINVAL;
  }

  p = proc_addr(proc_nr);

  switch(m_ptr->SVMCTL_PARAM) {
	case VMCTL_CLEAR_PAGEFAULT:
		RTS_LOCK_UNSET(p, RTS_PAGEFAULT);
		return OK;
	case VMCTL_MEMREQ_GET:
		/* Send VM the information about the memory request.  */
		if(!(rp = vmrequest))
			return ESRCH;
		vmassert(RTS_ISSET(rp, RTS_VMREQUEST));

#if 0
		printf("kernel: vm request sent by: %s / %d about %d; 0x%lx-0x%lx, wr %d, stack: %s ",
			rp->p_name, rp->p_endpoint, rp->p_vmrequest.who,
			rp->p_vmrequest.start,
			rp->p_vmrequest.start + rp->p_vmrequest.length,
			rp->p_vmrequest.writeflag, rp->p_vmrequest.stacktrace);
		printf("type %d\n", rp->p_vmrequest.type);
#endif

#if DEBUG_VMASSERT
  		okendpt(rp->p_vmrequest.who, &proc_nr);
		target = proc_addr(proc_nr);
#if 0
		if(!RTS_ISSET(target, RTS_VMREQTARGET)) {
			printf("set stack: %s\n", rp->p_vmrequest.stacktrace);
			minix_panic("RTS_VMREQTARGET not set for target",
				NO_NUM);
		}
#endif
#endif

		/* Reply with request fields. */
		switch(rp->p_vmrequest.req_type) {
		case VMPTYPE_CHECK:
			m_ptr->SVMCTL_MRG_TARGET	=
				rp->p_vmrequest.target;
			m_ptr->SVMCTL_MRG_ADDR		=
				rp->p_vmrequest.params.check.start;
			m_ptr->SVMCTL_MRG_LENGTH	=
				rp->p_vmrequest.params.check.length;
			m_ptr->SVMCTL_MRG_FLAG		=
				rp->p_vmrequest.params.check.writeflag;
			m_ptr->SVMCTL_MRG_REQUESTOR	=
				(void *) rp->p_endpoint;
			break;
		case VMPTYPE_COWMAP:
		case VMPTYPE_SMAP:
		case VMPTYPE_SUNMAP:
			m_ptr->SVMCTL_MRG_TARGET	=
				rp->p_vmrequest.target;
			m_ptr->SVMCTL_MRG_ADDR		=
				rp->p_vmrequest.params.map.vir_d;
			m_ptr->SVMCTL_MRG_EP2		=
				rp->p_vmrequest.params.map.ep_s;
			m_ptr->SVMCTL_MRG_ADDR2		=
				rp->p_vmrequest.params.map.vir_s;
			m_ptr->SVMCTL_MRG_LENGTH	=
				rp->p_vmrequest.params.map.length;
			m_ptr->SVMCTL_MRG_FLAG		=
				rp->p_vmrequest.params.map.writeflag;
			m_ptr->SVMCTL_MRG_REQUESTOR	=
				(void *) rp->p_endpoint;
			break;
		default:
			minix_panic("VMREQUEST wrong type", NO_NUM);
		}

		rp->p_vmrequest.vmresult = VMSUSPEND;

		/* Remove from request chain. */
		vmrequest = vmrequest->p_vmrequest.nextrequestor;

		return rp->p_vmrequest.req_type;
	case VMCTL_MEMREQ_REPLY:
		vmassert(RTS_ISSET(p, RTS_VMREQUEST));
		vmassert(p->p_vmrequest.vmresult == VMSUSPEND);
  		okendpt(p->p_vmrequest.target, &proc_nr);
		target = proc_addr(proc_nr);
		p->p_vmrequest.vmresult = m_ptr->SVMCTL_VALUE;
		vmassert(p->p_vmrequest.vmresult != VMSUSPEND);
#if DEBUG_VMASSERT
		if(p->p_vmrequest.vmresult != OK)
			kprintf("SYSTEM: VM replied %d to mem request\n",
				p->p_vmrequest.vmresult);

		printf("memreq reply: vm request sent by: %s / %d about %d; 0x%lx-0x%lx, wr %d, stack: %s ",
			p->p_name, p->p_endpoint, p->p_vmrequest.who,
			p->p_vmrequest.start,
			p->p_vmrequest.start + p->p_vmrequest.length,
			p->p_vmrequest.writeflag, p->p_vmrequest.stacktrace);
		printf("type %d\n", p->p_vmrequest.type);
#endif

		vmassert(RTS_ISSET(target, RTS_VMREQTARGET));
		RTS_LOCK_UNSET(target, RTS_VMREQTARGET);

		switch(p->p_vmrequest.type) {
		case VMSTYPE_KERNELCALL:
			/*
			 * we will have to resume execution of the kernel call
			 * as soon the scheduler picks up this process again
			 */
			p->p_misc_flags |= MF_KCALL_RESUME;
			break;
		case VMSTYPE_DELIVERMSG:
			vmassert(p->p_misc_flags & MF_DELIVERMSG);
			vmassert(p == target);
			vmassert(RTS_ISSET(p, RTS_VMREQUEST));
			break;
		case VMSTYPE_MAP:
			vmassert(RTS_ISSET(p, RTS_VMREQUEST));
			break;
		default:
#if DEBUG_VMASSERT
			printf("suspended with stack: %s\n",
				p->p_vmrequest.stacktrace);
#endif
			minix_panic("strange request type",
				p->p_vmrequest.type);
		}

		RTS_LOCK_UNSET(p, RTS_VMREQUEST);
		return OK;

	case VMCTL_ENABLE_PAGING:
		/*
		 * system task must not get preempted while switching to paging,
		 * interrupt handling is not safe
		 */
		lock;
		if(vm_running) 
			minix_panic("do_vmctl: paging already enabled", NO_NUM);
		vm_init(p);
		if(!vm_running)
			minix_panic("do_vmctl: paging enabling failed", NO_NUM);
		vmassert(p->p_delivermsg_lin ==
		  umap_local(p, D, p->p_delivermsg_vir, sizeof(message)));
		if ((err = arch_enable_paging()) != OK) {
			unlock;
			return err;
		}
		if(newmap(caller, p, (struct mem_map *) m_ptr->SVMCTL_VALUE) != OK)
			minix_panic("do_vmctl: newmap failed", NO_NUM);
		FIXLINMSG(p);
		vmassert(p->p_delivermsg_lin);
		unlock;
		return OK;
	case VMCTL_KERN_PHYSMAP:
	{
		int i = m_ptr->SVMCTL_VALUE;
		return arch_phys_map(i,
			(phys_bytes *) &m_ptr->SVMCTL_MAP_PHYS_ADDR,
			(phys_bytes *) &m_ptr->SVMCTL_MAP_PHYS_LEN,
			&m_ptr->SVMCTL_MAP_FLAGS);
	}
	case VMCTL_KERN_MAP_REPLY:
	{
		return arch_phys_map_reply(m_ptr->SVMCTL_VALUE,
			(vir_bytes) m_ptr->SVMCTL_MAP_VIR_ADDR);
	}
  }

  /* Try architecture-specific vmctls. */
  return arch_do_vmctl(m_ptr, p);
}