FreeBSD/Linux Kernel Cross Reference
sys/amd64/amd64/vm_machdep.c

     /*-
      * Copyright (c) 1982, 1986 The Regents of the University of California.
      * Copyright (c) 1989, 1990 William Jolitz
      * Copyright (c) 1994 John Dyson
      * All rights reserved.
      *
      * This code is derived from software contributed to Berkeley by
      * the Systems Programming Group of the University of Utah Computer
      * Science Department, and William Jolitz.
     *
     * Redistribution and use in source and binary forms, with or without
     * modification, are permitted provided that the following conditions
     * are met:
     * 1. Redistributions of source code must retain the above copyright
     *    notice, this list of conditions and the following disclaimer.
     * 2. Redistributions in binary form must reproduce the above copyright
     *    notice, this list of conditions and the following disclaimer in the
     *    documentation and/or other materials provided with the distribution.
     * 3. All advertising materials mentioning features or use of this software
     *    must display the following acknowledgement:
     *      This product includes software developed by the University of
     *      California, Berkeley and its contributors.
     * 4. Neither the name of the University nor the names of its contributors
     *    may be used to endorse or promote products derived from this software
     *    without specific prior written permission.
     *
     * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     * SUCH DAMAGE.
     *
     *      from: @(#)vm_machdep.c  7.3 (Berkeley) 5/13/91
     *      Utah $Hdr: vm_machdep.c 1.16.1.1 89/06/23$
     * $FreeBSD: releng/5.1/sys/amd64/amd64/vm_machdep.c 115251 2003-05-23 05:04:54Z peter $
     */
    
    #include "opt_isa.h"
    #include "opt_kstack_pages.h"
    
    #include <sys/param.h>
    #include <sys/systm.h>
    #include <sys/malloc.h>
    #include <sys/proc.h>
    #include <sys/kse.h>
    #include <sys/bio.h>
    #include <sys/buf.h>
    #include <sys/vnode.h>
    #include <sys/vmmeter.h>
    #include <sys/kernel.h>
    #include <sys/ktr.h>
    #include <sys/mutex.h>
    #include <sys/sysctl.h>
    #include <sys/unistd.h>
    
    #include <machine/cpu.h>
    #include <machine/md_var.h>
    #include <machine/pcb.h>
    
    #include <vm/vm.h>
    #include <vm/vm_param.h>
    #include <sys/lock.h>
    #include <vm/vm_kern.h>
    #include <vm/vm_page.h>
    #include <vm/vm_map.h>
    #include <vm/vm_extern.h>
    
    #include <sys/user.h>
    
    #include <amd64/isa/isa.h>
    
    static void     cpu_reset_real(void);
    
    /*
     * Finish a fork operation, with process p2 nearly set up.
     * Copy and update the pcb, set up the stack so that the child
     * ready to run and return to user mode.
     */
    void
    cpu_fork(td1, p2, td2, flags)
            register struct thread *td1;
            register struct proc *p2;
            struct thread *td2;
            int flags;
    {
            register struct proc *p1;
            struct pcb *pcb2;
            struct mdproc *mdp2;
            register_t savecrit;
    
            p1 = td1->td_proc;
            if ((flags & RFPROC) == 0)
                    return;
   
           /* Ensure that p1's pcb is up to date. */
           savecrit = intr_disable();
           if (PCPU_GET(fpcurthread) == td1)
                   npxsave(&td1->td_pcb->pcb_save);
           intr_restore(savecrit);
   
           /* Point the pcb to the top of the stack */
           pcb2 = (struct pcb *)(td2->td_kstack + KSTACK_PAGES * PAGE_SIZE) - 1;
           td2->td_pcb = pcb2;
   
           /* Copy p1's pcb */
           bcopy(td1->td_pcb, pcb2, sizeof(*pcb2));
   
           /* Point mdproc and then copy over td1's contents */
           mdp2 = &p2->p_md;
           bcopy(&p1->p_md, mdp2, sizeof(*mdp2));
   
           /*
            * Create a new fresh stack for the new process.
            * Copy the trap frame for the return to user mode as if from a
            * syscall.  This copies most of the user mode register values.
            */
           td2->td_frame = (struct trapframe *)td2->td_pcb - 1;
           bcopy(td1->td_frame, td2->td_frame, sizeof(struct trapframe));
   
           td2->td_frame->tf_rax = 0;              /* Child returns zero */
           td2->td_frame->tf_rflags &= ~PSL_C;     /* success */
           td2->td_frame->tf_rdx = 1;
   
           /*
            * Set registers for trampoline to user mode.  Leave space for the
            * return address on stack.  These are the kernel mode register values.
            */
           pcb2->pcb_cr3 = vtophys(vmspace_pmap(p2->p_vmspace)->pm_pml4);
           pcb2->pcb_r12 = (register_t)fork_return;        /* fork_trampoline argument */
           pcb2->pcb_rbp = 0;
           pcb2->pcb_rsp = (register_t)td2->td_frame - sizeof(void *);
           pcb2->pcb_rbx = (register_t)td2;                /* fork_trampoline argument */
           pcb2->pcb_rip = (register_t)fork_trampoline;
           pcb2->pcb_rflags = td2->td_frame->tf_rflags & ~PSL_I; /* ints disabled */
           /*-
            * pcb2->pcb_savefpu:   cloned above.
            * pcb2->pcb_flags:     cloned above.
            * pcb2->pcb_onfault:   cloned above (always NULL here?).
            * pcb2->pcb_[fg]sbase: cloned above
            */
   
           /*
            * Now, cpu_switch() can schedule the new process.
            * pcb_rsp is loaded pointing to the cpu_switch() stack frame
            * containing the return address when exiting cpu_switch.
            * This will normally be to fork_trampoline(), which will have
            * %ebx loaded with the new proc's pointer.  fork_trampoline()
            * will set up a stack to call fork_return(p, frame); to complete
            * the return to user-mode.
            */
   }
   
   /*
    * Intercept the return address from a freshly forked process that has NOT
    * been scheduled yet.
    *
    * This is needed to make kernel threads stay in kernel mode.
    */
   void
   cpu_set_fork_handler(td, func, arg)
           struct thread *td;
           void (*func)(void *);
           void *arg;
   {
           /*
            * Note that the trap frame follows the args, so the function
            * is really called like this:  func(arg, frame);
            */
           td->td_pcb->pcb_r12 = (long) func;      /* function */
           td->td_pcb->pcb_rbx = (long) arg;       /* first arg */
   }
   
   void
   cpu_exit(struct thread *td)
   {
           struct mdproc *mdp;
   
           mdp = &td->td_proc->p_md;
   }
   
   void
   cpu_thread_exit(struct thread *td)
   {
   
           npxexit(td);
   }
   
   void
   cpu_thread_clean(struct thread *td)
   {
   }
   
   void
   cpu_sched_exit(td)
           register struct thread *td;
   {
   }
   
   void
   cpu_thread_setup(struct thread *td)
   {
   
           td->td_pcb =
                (struct pcb *)(td->td_kstack + KSTACK_PAGES * PAGE_SIZE) - 1;
           td->td_frame = (struct trapframe *)td->td_pcb - 1;
   }
   
   /*
    * Initialize machine state (pcb and trap frame) for a new thread about to
    * upcall. Pu t enough state in the new thread's PCB to get it to go back 
    * userret(), where we can intercept it again to set the return (upcall)
    * Address and stack, along with those from upcals that are from other sources
    * such as those generated in thread_userret() itself.
    */
   void
   cpu_set_upcall(struct thread *td, void *pcb)
   {
   }
   
   /*
    * Set that machine state for performing an upcall that has to
    * be done in thread_userret() so that those upcalls generated
    * in thread_userret() itself can be done as well.
    */
   void
   cpu_set_upcall_kse(struct thread *td, struct kse_upcall *ku)
   {
   }
   
   void
   cpu_wait(p)
           struct proc *p;
   {
   }
   
   /*
    * Force reset the processor by invalidating the entire address space!
    */
   
   void
   cpu_reset()
   {
           cpu_reset_real();
   }
   
   static void
   cpu_reset_real()
   {
   
           /*
            * Attempt to do a CPU reset via the keyboard controller,
            * do not turn of the GateA20, as any machine that fails
            * to do the reset here would then end up in no man's land.
            */
   
           outb(IO_KBD + 4, 0xFE);
           DELAY(500000);  /* wait 0.5 sec to see if that did it */
           printf("Keyboard reset did not work, attempting CPU shutdown\n");
           DELAY(1000000); /* wait 1 sec for printf to complete */
           /* force a shutdown by unmapping entire address space ! */
           bzero((caddr_t)PML4map, PAGE_SIZE);
   
           /* "good night, sweet prince .... <THUNK!>" */
           invltlb();
           /* NOTREACHED */
           while(1);
   }
   
   /*
    * Software interrupt handler for queued VM system processing.
    */   
   void  
   swi_vm(void *dummy) 
   {     
           if (busdma_swi_pending != 0)
                   busdma_swi();
   }
   
   /*
    * Tell whether this address is in some physical memory region.
    * Currently used by the kernel coredump code in order to avoid
    * dumping the ``ISA memory hole'' which could cause indefinite hangs,
    * or other unpredictable behaviour.
    */
   
   int
   is_physical_memory(addr)
           vm_offset_t addr;
   {
   
   #ifdef DEV_ISA
           /* The ISA ``memory hole''. */
           if (addr >= 0xa0000 && addr < 0x100000)
                   return 0;
   #endif
   
           /*
            * stuff other tests for known memory-mapped devices (PCI?)
            * here
            */
   
           return 1;
   }

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