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/* $OpenBSD: vm_machdep.c,v 1.3 2020/06/22 16:58:20 kettenis Exp $ */
/*-
* Copyright (c) 1995 Charles M. Hannum. All rights reserved.
* Copyright (c) 1982, 1986 The Regents of the University of California.
* Copyright (c) 1989, 1990 William Jolitz
* 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. 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.
*
* @(#)vm_machdep.c 7.3 (Berkeley) 5/13/91
*/
/*
* Utah $Hdr: vm_machdep.c 1.16.1.1 89/06/23$
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/malloc.h>
#include <sys/vnode.h>
#include <sys/buf.h>
#include <sys/user.h>
#include <sys/exec.h>
#include <sys/ptrace.h>
#include <sys/signalvar.h>
#include <uvm/uvm_extern.h>
#include <machine/cpu.h>
#include <machine/reg.h>
/*
* Finish a fork operation, with process p2 nearly set up.
* Copy and update the kernel stack and pcb, making the child
* ready to run, and marking it so that it can return differently
* than the parent. Returns 1 in the child process, 0 in the parent.
*/
void
cpu_fork(struct proc *p1, struct proc *p2, void *stack, void *tcb,
void (*func)(void *), void *arg)
{
pmap_t pm = p2->p_vmspace->vm_map.pmap;
struct pcb *pcb = &p2->p_addr->u_pcb;
struct trapframe *tf;
struct callframe *cf;
struct switchframe *sf;
register_t kstack;
/* Copy the pcb. */
*pcb = p1->p_addr->u_pcb;
pmap_extract(pmap_kernel(), (vaddr_t)&pm->pm_slb,
&p2->p_md.md_user_slb_pa);
pmap_activate(p2);
kstack = (register_t)p2->p_addr + USPACE - FRAMELEN -
(arc4random() & PAGE_MASK & ~_STACKALIGNBYTES);
p2->p_md.md_regs = tf = (struct trapframe *)kstack;
*tf = *p1->p_md.md_regs;
if (stack != NULL)
tf->fixreg[1] = STACKALIGN(stack);
if (tcb != NULL)
tf->fixreg[13] = (register_t)tcb;
cf = (struct callframe *)tf - 1;
memset(cf, 0, sizeof(*cf));
cf->cf_lr = (register_t)&proc_trampoline;
sf = (struct switchframe *)cf - 1;
memset(sf, 0, sizeof(*sf));
sf->sf_r31 = (register_t)func;
sf->sf_r30 = (register_t)arg;
pcb->pcb_sp = (register_t)sf;
}
/*
* cpu_exit is called as the last action during exit.
*
* We clean up a little and then call sched_exit() with the old proc as an
* argument.
*/
void
cpu_exit(struct proc *p)
{
#if 0
/* If we were using the FPU, forget about it. */
if (p->p_addr->u_pcb.pcb_fpcpu != NULL)
vfp_discard(p);
#endif
pmap_deactivate(p);
sched_exit(p);
}
struct kmem_va_mode kv_physwait = {
.kv_map = &phys_map,
.kv_wait = 1,
};
/*
* Map a user I/O request into kernel virtual address space.
* Note: the pages are already locked by uvm_vslock(), so we
* do not need to pass an access_type to pmap_enter().
*/
void
vmapbuf(struct buf *bp, vsize_t len)
{
vaddr_t faddr, taddr, off;
paddr_t fpa;
if ((bp->b_flags & B_PHYS) == 0)
panic("vmapbuf");
faddr = trunc_page((vaddr_t)(bp->b_saveaddr = bp->b_data));
off = (vaddr_t)bp->b_data - faddr;
len = round_page(off + len);
taddr = (vaddr_t)km_alloc(len, &kv_physwait, &kp_none, &kd_waitok);
bp->b_data = (caddr_t)(taddr + off);
/*
* The region is locked, so we expect that pmap_pte() will return
* non-NULL.
* XXX: unwise to expect this in a multithreaded environment.
* anything can happen to a pmap between the time we lock a
* region, release the pmap lock, and then relock it for
* the pmap_extract().
*
* no need to flush TLB since we expect nothing to be mapped
* where we we just allocated (TLB will be flushed when our
* mapping is removed).
*/
while (len) {
(void) pmap_extract(vm_map_pmap(&bp->b_proc->p_vmspace->vm_map),
faddr, &fpa);
pmap_kenter_pa(taddr, fpa, PROT_READ | PROT_WRITE);
faddr += PAGE_SIZE;
taddr += PAGE_SIZE;
len -= PAGE_SIZE;
}
pmap_update(pmap_kernel());
}
/*
* Unmap a previously-mapped user I/O request.
*/
void
vunmapbuf(struct buf *bp, vsize_t len)
{
vaddr_t addr, off;
if ((bp->b_flags & B_PHYS) == 0)
panic("vunmapbuf");
addr = trunc_page((vaddr_t)bp->b_data);
off = (vaddr_t)bp->b_data - addr;
len = round_page(off + len);
pmap_kremove(addr, len);
pmap_update(pmap_kernel());
km_free((void *)addr, len, &kv_physwait, &kp_none);
bp->b_data = bp->b_saveaddr;
bp->b_saveaddr = 0;
}
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