/* $OpenBSD: vm_machdep.c,v 1.39 2007/05/27 20:59:25 miod Exp $ */
/* $NetBSD: vm_machdep.c,v 1.29 1998/07/28 18:34:55 thorpej Exp $ */
/*
* Copyright (c) 1988 University of Utah.
* Copyright (c) 1982, 1986, 1990, 1993
* The Regents of the University of California. 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.
*
* 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.
*/
/*
* from: Utah $Hdr: vm_machdep.c 1.21 91/04/06$
*
* @(#)vm_machdep.c 8.6 (Berkeley) 1/12/94
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/signalvar.h>
#include <sys/malloc.h>
#include <sys/buf.h>
#include <sys/user.h>
#include <sys/vnode.h>
#include <sys/core.h>
#include <sys/exec.h>
#include <sys/ptrace.h>
#include <uvm/uvm_extern.h>
#include <machine/cpu.h>
#include <machine/pmap.h>
#include <machine/pte.h>
#include <machine/reg.h>
void savectx(struct pcb *);
/*
* 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.
* We currently double-map the user area so that the stack is at the same
* address in each process; in the future we will probably relocate
* the frame pointers on the stack after copying.
*/
void
cpu_fork(p1, p2, stack, stacksize, func, arg)
struct proc *p1, *p2;
void *stack;
size_t stacksize;
void (*func)(void *);
void *arg;
{
struct pcb *pcb = &p2->p_addr->u_pcb;
struct trapframe *tf;
struct switchframe *sf;
extern struct pcb *curpcb;
p2->p_md.md_flags = p1->p_md.md_flags;
/* Copy pcb from proc p1 to p2. */
if (p1 == curproc) {
/* Sync the PCB before we copy it. */
savectx(curpcb);
}
#ifdef DIAGNOSTIC
else if (p1 != &proc0)
panic("cpu_fork: curproc");
#endif
*pcb = p1->p_addr->u_pcb;
/*
* Copy the trap frame.
*/
tf = (struct trapframe *)((u_int)p2->p_addr + USPACE) -1;
p2->p_md.md_regs = (int *)tf;
*tf = *(struct trapframe *)p1->p_md.md_regs;
/*
* If specified, give the child a different stack.
*/
if (stack != NULL)
tf->tf_regs[15] = (u_int)stack + stacksize;
sf = (struct switchframe *)tf - 1;
sf->sf_pc = (u_int)proc_trampoline;
pcb->pcb_regs[6] = (int)func; /* A2 */
pcb->pcb_regs[7] = (int)arg; /* A3 */
pcb->pcb_regs[11] = (int)sf; /* SSP */
pcb->pcb_ps = PSL_LOWIPL; /* start kthreads at IPL 0 */
}
/*
* cpu_exit is called as the last action during exit.
* We release the address space and machine-dependent resources,
* block context switches and then call switch_exit() which will
* free our stack and user area and switch to another process.
* Thus, we never return.
*/
void
cpu_exit(p)
struct proc *p;
{
(void)splhigh();
switch_exit(p);
/* NOTREACHED */
}
/*
* Dump the machine specific segment at the start of a core dump.
* This means the CPU and FPU registers. The format used here is
* the same one ptrace uses, so gdb can be machine independent.
*
* XXX - Generate Sun format core dumps for Sun executables?
*/
struct md_core {
struct reg intreg;
struct fpreg freg;
};
int
cpu_coredump(p, vp, cred, chdr)
struct proc *p;
struct vnode *vp;
struct ucred *cred;
struct core *chdr;
{
struct md_core md_core;
struct coreseg cseg;
int error;
CORE_SETMAGIC(*chdr, COREMAGIC, MID_MACHINE, 0);
chdr->c_hdrsize = ALIGN(sizeof(*chdr));
chdr->c_seghdrsize = ALIGN(sizeof(cseg));
chdr->c_cpusize = sizeof(md_core);
/* Save integer registers. */
error = process_read_regs(p, &md_core.intreg);
if (error)
return error;
if (fputype) {
/* Save floating point registers. */
error = process_read_fpregs(p, &md_core.freg);
if (error)
return error;
} else {
/* Make sure these are clear. */
bzero((caddr_t)&md_core.freg, sizeof(md_core.freg));
}
CORE_SETMAGIC(cseg, CORESEGMAGIC, MID_MACHINE, CORE_CPU);
cseg.c_addr = 0;
cseg.c_size = chdr->c_cpusize;
error = vn_rdwr(UIO_WRITE, vp, (caddr_t)&cseg, chdr->c_seghdrsize,
(off_t)chdr->c_hdrsize, UIO_SYSSPACE, IO_NODELOCKED|IO_UNIT, cred,
NULL, p);
if (error)
return error;
error = vn_rdwr(UIO_WRITE, vp, (caddr_t)&md_core, sizeof(md_core),
(off_t)(chdr->c_hdrsize + chdr->c_seghdrsize), UIO_SYSSPACE,
IO_NODELOCKED|IO_UNIT, cred, NULL, p);
if (error)
return error;
chdr->c_nseg++;
return 0;
}
/*
* Map an IO request into kernel virtual address space.
*
* XXX we allocate KVA space by using kmem_alloc_wait which we know
* allocates space without backing physical memory. This implementation
* is a total crock, the multiple mappings of these physical pages should
* be reflected in the higher-level VM structures to avoid problems.
*/
void
vmapbuf(bp, len)
struct buf *bp;
vsize_t len;
{
struct pmap *upmap, *kpmap;
vaddr_t uva; /* User VA (map from) */
vaddr_t kva; /* Kernel VA (new to) */
vaddr_t pa; /* physical address */
vsize_t off;
#ifdef DIAGNOSTIC
if ((bp->b_flags & B_PHYS) == 0)
panic("vmapbuf");
#endif
uva = trunc_page((vaddr_t)(bp->b_saveaddr = bp->b_data));
off = (vaddr_t)bp->b_data - uva;
len = round_page(off + len);
kva = uvm_km_valloc_wait(phys_map, len);
bp->b_data = (caddr_t)(kva + off);
upmap = vm_map_pmap(&bp->b_proc->p_vmspace->vm_map);
kpmap = vm_map_pmap(phys_map);
do {
if (pmap_extract(upmap, uva, &pa) == FALSE)
panic("vmapbuf: null page frame");
pmap_enter(kpmap, kva, pa, VM_PROT_READ | VM_PROT_WRITE,
VM_PROT_READ | VM_PROT_WRITE | PMAP_WIRED);
uva += PAGE_SIZE;
kva += PAGE_SIZE;
len -= PAGE_SIZE;
} while (len);
pmap_update(pmap_kernel());
}
/*
* Free the io map PTEs associated with this IO operation.
*/
void
vunmapbuf(bp, len)
struct buf *bp;
vsize_t len;
{
vaddr_t kva;
vsize_t off;
#ifdef DIAGNOSTIC
if ((bp->b_flags & B_PHYS) == 0)
panic("vunmapbuf");
#endif
kva = trunc_page((vaddr_t)bp->b_data);
off = (vaddr_t)bp->b_data - kva;
len = round_page(off + len);
pmap_remove(vm_map_pmap(phys_map), kva, kva + len);
pmap_update(pmap_kernel());
uvm_km_free_wakeup(phys_map, kva, len);
bp->b_data = bp->b_saveaddr;
bp->b_saveaddr = 0;
}