1 /* $NetBSD: vm_machdep.c,v 1.48 2026/08/30 00:46:50 thorpej Exp $ */ 2 3 /* 4 * Copyright (c) 1988 University of Utah. 5 * Copyright (c) 1982, 1986, 1990, 1993 6 * The Regents of the University of California. All rights reserved. 7 * 8 * This code is derived from software contributed to Berkeley by 9 * the Systems Programming Group of the University of Utah Computer 10 * Science Department. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * from: Utah $Hdr: vm_machdep.c 1.21 91/04/06$ 37 * 38 * @(#)vm_machdep.c 8.6 (Berkeley) 1/12/94 39 */ 40 41 #include <sys/cdefs.h> 42 __KERNEL_RCSID(0, "$NetBSD: vm_machdep.c,v 1.48 2026/08/30 00:46:50 thorpej Exp $"); 43 44 #include <sys/param.h> 45 #include <sys/systm.h> 46 #include <sys/proc.h> 47 #include <sys/cpu.h> 48 #include <sys/buf.h> 49 #include <sys/vnode.h> 50 #include <sys/core.h> 51 #include <sys/exec.h> 52 53 #include <machine/frame.h> 54 #include <machine/pcb.h> 55 56 #include <uvm/uvm_extern.h> 57 58 struct vm_map *phys_map; 59 60 __CTASSERT(USPACE >= PAGE_SIZE); 61 __CTASSERT((USPACE & PAGE_MASK) == 0); 62 63 void 64 cpu_proc_fork(struct proc *p1, struct proc *p2) 65 { 66 67 p2->p_md.mdp_flags = p1->p_md.mdp_flags; 68 } 69 70 /* 71 * Finish a fork operation, with process l2 nearly set up. 72 * Copy and update the pcb and trap frame, making the child ready to run. 73 * 74 * Rig the child's kernel stack so that it will start out in 75 * lwp_trampoline() and call child_return() with l2 as an 76 * argument. This causes the newly-created child process to go 77 * directly to user level with an apparent return value of 0 from 78 * fork(), while the parent process returns normally. 79 * 80 * l1 is the process being forked; if l1 == &lwp0, we are creating 81 * a kernel thread, and the return path and argument are specified with 82 * `func' and `arg'. 83 * 84 * If an alternate user-level stack is requested (with non-zero values 85 * in both the stack and stacksize args), set up the user stack pointer 86 * accordingly. 87 */ 88 void 89 cpu_lwp_fork(struct lwp *l1, struct lwp *l2, void *stack, size_t stacksize, 90 void (*func)(void *), void *arg) 91 { 92 struct pcb *pcb1, *pcb2; 93 struct trapframe *tf; 94 struct switchframe *sf; 95 96 pcb1 = lwp_getpcb(l1); 97 pcb2 = lwp_getpcb(l2); 98 99 l2->l_md.md_flags = l1->l_md.md_flags; 100 101 /* Copy pcb from lwp l1 to l2. */ 102 if (l1 == curlwp) { 103 /* Sync the PCB before we copy it. */ 104 savectx(curpcb); 105 } else { 106 KASSERT(l1 == &lwp0); 107 } 108 109 *pcb2 = *pcb1; 110 111 /* 112 * Copy the trap frame. 113 */ 114 tf = (struct trapframe *)(uvm_lwp_getuarea(l2) + USPACE) - 1; 115 l2->l_md.md_regs = (int *)tf; 116 *tf = *(struct trapframe *)l1->l_md.md_regs; 117 118 /* 119 * If specified, give the child a different stack. 120 */ 121 if (stack != NULL) { 122 tf->tf_regs[15] = 123 ((uintptr_t)stack + stacksize) & ~STACK_ALIGNBYTES; 124 } 125 126 sf = (struct switchframe *)tf - 1; 127 sf->sf_pc = (u_int)lwp_trampoline; 128 pcb2->pcb_regs[6] = (int)func; /* A2 */ 129 pcb2->pcb_regs[7] = (int)arg; /* A3 */ 130 pcb2->pcb_regs[8] = (int)l2; /* A4 */ 131 pcb2->pcb_regs[11] = (int)sf; /* SSP */ 132 pcb2->pcb_ps = PSL_LOWIPL; /* start kthreads at IPL 0 */ 133 } 134 135 void 136 cpu_lwp_free(struct lwp *l, int proc) 137 { 138 139 /* Nothing to do */ 140 } 141 142 void 143 cpu_lwp_free2(struct lwp *l) 144 { 145 146 /* Nothing to do */ 147 } 148 149 /* 150 * Ensure phys_map is large enough for at least 2 concurrent 151 * MAXPHYS transfers. 152 */ 153 __CTASSERT((MAXPHYS * 2) <= VM_PHYS_SIZE); 154 155 /* 156 * Map a user I/O request into kernel virtual address space. 157 * Note: the pages are already locked by uvm_vslock(), so we 158 * do not need to pass an access_type to pmap_enter(). 159 */ 160 int 161 vmapbuf(struct buf *bp, vsize_t len) 162 { 163 struct pmap *upmap, *kpmap __unused; 164 vaddr_t uva; /* User VA (map from) */ 165 vaddr_t kva; /* Kernel VA (new to) */ 166 paddr_t pa; /* physical address */ 167 vsize_t off; 168 169 if ((bp->b_flags & B_PHYS) == 0) 170 panic("vmapbuf"); 171 172 uva = m68k_trunc_page(bp->b_saveaddr = bp->b_data); 173 off = (vaddr_t)bp->b_data - uva; 174 len = m68k_round_page(off + len); 175 kva = uvm_km_alloc(phys_map, len, 0, UVM_KMF_VAONLY | UVM_KMF_WAITVA); 176 bp->b_data = (void *)(kva + off); 177 178 upmap = vm_map_pmap(&bp->b_proc->p_vmspace->vm_map); 179 kpmap = vm_map_pmap(phys_map); 180 do { 181 if (pmap_extract(upmap, uva, &pa) == false) 182 panic("vmapbuf: null page frame"); 183 #ifdef M68K_VAC 184 pmap_enter(kpmap, kva, pa, VM_PROT_READ | VM_PROT_WRITE, 185 PMAP_WIRED); 186 #else 187 pmap_kenter_pa(kva, pa, VM_PROT_READ | VM_PROT_WRITE, 0); 188 #endif 189 uva += PAGE_SIZE; 190 kva += PAGE_SIZE; 191 len -= PAGE_SIZE; 192 } while (len); 193 pmap_update(kpmap); 194 195 return 0; 196 } 197 198 /* 199 * Unmap a previously-mapped user I/O request. 200 */ 201 void 202 vunmapbuf(struct buf *bp, vsize_t len) 203 { 204 vaddr_t kva; 205 vsize_t off; 206 207 if ((bp->b_flags & B_PHYS) == 0) 208 panic("vunmapbuf"); 209 210 kva = m68k_trunc_page(bp->b_data); 211 off = (vaddr_t)bp->b_data - kva; 212 len = m68k_round_page(off + len); 213 214 #ifdef M68K_VAC 215 pmap_remove(vm_map_pmap(phys_map), kva, kva + len); 216 #else 217 pmap_kremove(kva, len); 218 #endif 219 pmap_update(pmap_kernel()); 220 uvm_km_free(phys_map, kva, len, UVM_KMF_VAONLY); 221 bp->b_data = bp->b_saveaddr; 222 bp->b_saveaddr = 0; 223 } 224
Indexes created Mon Oct 26 00:26:21 UTC 2026