/* $OpenBSD: vm_machdep.c,v 1.31 2025/05/21 09:06:58 mpi Exp $ */ /* * Copyright (c) 1998 Steve Murphree, Jr. * Copyright (c) 1996 Nivas Madhur * Copyright (c) 1993 Adam Glass * Copyright (c) 1988 University of Utah. * Copyright (c) 1982, 1986, 1990 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 $Hdr: vm_machdep.c 1.21 91/04/06$ * from: @(#)vm_machdep.c 7.10 (Berkeley) 5/7/91 * vm_machdep.c,v 1.3 1993/07/07 07:09:32 cgd Exp */ #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/exec.h> #include <sys/ptrace.h> #include <uvm/uvm_extern.h> #include <machine/mmu.h> #include <machine/cmmu.h> #include <machine/cpu.h> #include <machine/trap.h> extern 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. */ void cpu_fork(struct proc *p1, struct proc *p2, void *stack, void *tcb, void (*func)(void *), void *arg) { extern void proc_trampoline(void); struct m88100_pcb *mdpcb = &p2->p_addr->u_pcb.kernel_state; /* Copy pcb from 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 bcopy(&p1->p_addr->u_pcb, &p2->p_addr->u_pcb, sizeof(struct pcb)); p2->p_md.md_tf = (struct trapframe *)USER_REGS(p2); /* * If specified, give the child a different stack and/or TCB. */ if (stack != NULL) USER_REGS(p2)->r[31] = (u_int)stack; if (tcb != NULL) USER_REGS(p2)->r[27] = (u_int)tcb; /* * When this process resumes, the process will be at the beginning * of proc_trampoline(). proc_trampoline will execute the function * func and resume to userland. */ mdpcb->pcb_r14 = (u_int)func; mdpcb->pcb_r15 = (u_int)arg; mdpcb->pcb_sp = (u_int)((char *)p2->p_addr + USPACE); mdpcb->pcb_pc = (u_int)proc_trampoline; } void cpu_exit(struct proc *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 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 = NULL; }
