/* $OpenBSD: vm_machdep.c,v 1.75 2025/05/21 09:06:58 mpi Exp $ */ /* $NetBSD: vm_machdep.c,v 1.61 1996/05/03 19:42:35 christos 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/buf.h> #include <sys/user.h> #include <uvm/uvm_extern.h> #include "npx.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) { struct pcb *pcb = &p2->p_addr->u_pcb; struct trapframe *tf; struct switchframe *sf; #if NNPX > 0 npxsave_proc(p1, 1); #endif p2->p_md.md_flags = p1->p_md.md_flags; #ifdef DIAGNOSTIC if (p1 != curproc && p1 != &proc0) panic("cpu_fork: curproc"); #endif *pcb = p1->p_addr->u_pcb; pcb->pcb_kstack = (int)p2->p_addr + USPACE - 16 - (arc4random() & PAGE_MASK & ~_STACKALIGNBYTES); /* * Copy the trapframe, and arrange for the child to return directly */ p2->p_md.md_regs = tf = (struct trapframe *)pcb->pcb_kstack - 1; *tf = *p1->p_md.md_regs; /* * If specified, give the child a different stack and/or TCB */ if (stack != NULL) tf->tf_esp = (u_int)stack; if (tcb != NULL) i386_set_threadbase(p2, (uint32_t)tcb, TSEG_GS); sf = (struct switchframe *)tf - 1; sf->sf_esi = (int)func; sf->sf_ebx = (int)arg; sf->sf_eip = (int)proc_trampoline; pcb->pcb_esp = (int)sf; pcb->pcb_ebp = 0; } void cpu_exit(struct proc *p) { #if NNPX > 0 /* If we were using the FPU, forget about it. */ if (p->p_addr->u_pcb.pcb_fpcpu != NULL) npxsave_proc(p, 0); #endif } /* * Convert kernel VA to physical address */ int kvtop(caddr_t addr) { paddr_t pa; if (pmap_extract(pmap_kernel(), (vaddr_t)addr, &pa) == FALSE) panic("kvtop: zero page frame"); return((int)pa); } 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; }
