1 /* $NetBSD: vm_machdep.c,v 1.43 2024/01/19 03:35:31 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 1.43 2024/01/19 03:35:31 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/pte.h>
55 #include <machine/pcb.h>
56
57 #include <uvm/uvm_extern.h>
58
59 void
cpu_proc_fork(struct proc * p1,struct proc * p2)60 cpu_proc_fork(struct proc *p1, struct proc *p2)
61 {
62
63 p2->p_md.mdp_flags = p1->p_md.mdp_flags;
64 }
65
66 /*
67 * Finish a fork operation, with process l2 nearly set up.
68 * Copy and update the pcb and trap frame, making the child ready to run.
69 *
70 * Rig the child's kernel stack so that it will start out in
71 * lwp_trampoline() and call child_return() with l2 as an
72 * argument. This causes the newly-created child process to go
73 * directly to user level with an apparent return value of 0 from
74 * fork(), while the parent process returns normally.
75 *
76 * l1 is the process being forked; if l1 == &lwp0, we are creating
77 * a kernel thread, and the return path and argument are specified with
78 * `func' and `arg'.
79 *
80 * If an alternate user-level stack is requested (with non-zero values
81 * in both the stack and stacksize args), set up the user stack pointer
82 * accordingly.
83 */
84 void
cpu_lwp_fork(struct lwp * l1,struct lwp * l2,void * stack,size_t stacksize,void (* func)(void *),void * arg)85 cpu_lwp_fork(struct lwp *l1, struct lwp *l2, void *stack, size_t stacksize,
86 void (*func)(void *), void *arg)
87 {
88 struct pcb *pcb1, *pcb2;
89 struct trapframe *tf;
90 struct switchframe *sf;
91
92 pcb1 = lwp_getpcb(l1);
93 pcb2 = lwp_getpcb(l2);
94
95 l2->l_md.md_flags = l1->l_md.md_flags;
96
97 /* Copy pcb from lwp l1 to l2. */
98 if (l1 == curlwp) {
99 /* Sync the PCB before we copy it. */
100 savectx(curpcb);
101 } else {
102 KASSERT(l1 == &lwp0);
103 }
104
105 *pcb2 = *pcb1;
106
107 /*
108 * Copy the trap frame.
109 */
110 tf = (struct trapframe *)(uvm_lwp_getuarea(l2) + USPACE) - 1;
111 l2->l_md.md_regs = (int *)tf;
112 *tf = *(struct trapframe *)l1->l_md.md_regs;
113
114 /*
115 * If specified, give the child a different stack.
116 */
117 if (stack != NULL)
118 tf->tf_regs[15] = (u_int)stack + stacksize;
119
120 sf = (struct switchframe *)tf - 1;
121 sf->sf_pc = (u_int)lwp_trampoline;
122 pcb2->pcb_regs[6] = (int)func; /* A2 */
123 pcb2->pcb_regs[7] = (int)arg; /* A3 */
124 pcb2->pcb_regs[8] = (int)l2; /* A4 */
125 pcb2->pcb_regs[11] = (int)sf; /* SSP */
126 pcb2->pcb_ps = PSL_LOWIPL; /* start kthreads at IPL 0 */
127 }
128
129 void
cpu_lwp_free(struct lwp * l,int proc)130 cpu_lwp_free(struct lwp *l, int proc)
131 {
132
133 /* Nothing to do */
134 }
135
136 void
cpu_lwp_free2(struct lwp * l)137 cpu_lwp_free2(struct lwp *l)
138 {
139
140 /* Nothing to do */
141 }
142
143 /*
144 * Map a user I/O request into kernel virtual address space.
145 * Note: the pages are already locked by uvm_vslock(), so we
146 * do not need to pass an access_type to pmap_enter().
147 */
148 int
vmapbuf(struct buf * bp,vsize_t len)149 vmapbuf(struct buf *bp, vsize_t len)
150 {
151 struct pmap *upmap, *kpmap __unused;
152 vaddr_t uva; /* User VA (map from) */
153 vaddr_t kva; /* Kernel VA (new to) */
154 paddr_t pa; /* physical address */
155 vsize_t off;
156
157 if ((bp->b_flags & B_PHYS) == 0)
158 panic("vmapbuf");
159
160 uva = m68k_trunc_page(bp->b_saveaddr = bp->b_data);
161 off = (vaddr_t)bp->b_data - uva;
162 len = m68k_round_page(off + len);
163 kva = uvm_km_alloc(phys_map, len, 0, UVM_KMF_VAONLY | UVM_KMF_WAITVA);
164 bp->b_data = (void *)(kva + off);
165
166 upmap = vm_map_pmap(&bp->b_proc->p_vmspace->vm_map);
167 kpmap = vm_map_pmap(phys_map);
168 do {
169 if (pmap_extract(upmap, uva, &pa) == false)
170 panic("vmapbuf: null page frame");
171 #ifdef M68K_VAC
172 pmap_enter(kpmap, kva, pa, VM_PROT_READ | VM_PROT_WRITE,
173 PMAP_WIRED);
174 #else
175 pmap_kenter_pa(kva, pa, VM_PROT_READ | VM_PROT_WRITE, 0);
176 #endif
177 uva += PAGE_SIZE;
178 kva += PAGE_SIZE;
179 len -= PAGE_SIZE;
180 } while (len);
181 pmap_update(kpmap);
182
183 return 0;
184 }
185
186 /*
187 * Unmap a previously-mapped user I/O request.
188 */
189 void
vunmapbuf(struct buf * bp,vsize_t len)190 vunmapbuf(struct buf *bp, vsize_t len)
191 {
192 vaddr_t kva;
193 vsize_t off;
194
195 if ((bp->b_flags & B_PHYS) == 0)
196 panic("vunmapbuf");
197
198 kva = m68k_trunc_page(bp->b_data);
199 off = (vaddr_t)bp->b_data - kva;
200 len = m68k_round_page(off + len);
201
202 #ifdef M68K_VAC
203 pmap_remove(vm_map_pmap(phys_map), kva, kva + len);
204 #else
205 pmap_kremove(kva, len);
206 #endif
207 pmap_update(pmap_kernel());
208 uvm_km_free(phys_map, kva, len, UVM_KMF_VAONLY);
209 bp->b_data = bp->b_saveaddr;
210 bp->b_saveaddr = 0;
211 }
212