1 /*- 2 * SPDX-License-Identifier: BSD-4-Clause 3 * 4 * Copyright (c) 1982, 1986 The Regents of the University of California. 5 * Copyright (c) 1989, 1990 William Jolitz 6 * Copyright (c) 1994 John Dyson 7 * All rights reserved. 8 * 9 * This code is derived from software contributed to Berkeley by 10 * the Systems Programming Group of the University of Utah Computer 11 * Science Department, and William Jolitz. 12 * 13 * Redistribution and use in source and binary :forms, with or without 14 * modification, are permitted provided that the following conditions 15 * are met: 16 * 1. Redistributions of source code must retain the above copyright 17 * notice, this list of conditions and the following disclaimer. 18 * 2. Redistributions in binary form must reproduce the above copyright 19 * notice, this list of conditions and the following disclaimer in the 20 * documentation and/or other materials provided with the distribution. 21 * 3. All advertising materials mentioning features or use of this software 22 * must display the following acknowledgement: 23 * This product includes software developed by the University of 24 * California, Berkeley and its contributors. 25 * 4. Neither the name of the University nor the names of its contributors 26 * may be used to endorse or promote products derived from this software 27 * without specific prior written permission. 28 * 29 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 30 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 31 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 32 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 33 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 34 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 35 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 36 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 37 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 38 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 39 * SUCH DAMAGE. 40 * 41 * from: @(#)vm_machdep.c 7.3 (Berkeley) 5/13/91 42 * Utah $Hdr: vm_machdep.c 1.16.1.1 89/06/23$ 43 */ 44 45 #include <sys/cdefs.h> 46 __FBSDID("$FreeBSD$"); 47 48 #include <sys/param.h> 49 #include <sys/systm.h> 50 #include <sys/kernel.h> 51 #include <sys/malloc.h> 52 #include <sys/mbuf.h> 53 #include <sys/proc.h> 54 #include <sys/socketvar.h> 55 #include <sys/syscall.h> 56 #include <sys/sysctl.h> 57 #include <sys/sysent.h> 58 #include <sys/unistd.h> 59 60 #include <machine/cpu.h> 61 #include <machine/frame.h> 62 #include <machine/pcb.h> 63 #include <machine/sysarch.h> 64 #include <sys/lock.h> 65 #include <sys/mutex.h> 66 67 #include <vm/vm.h> 68 #include <vm/pmap.h> 69 #include <vm/vm_extern.h> 70 #include <vm/vm_kern.h> 71 #include <vm/vm_page.h> 72 #include <vm/vm_map.h> 73 #include <vm/vm_param.h> 74 #include <vm/vm_pageout.h> 75 #include <vm/uma.h> 76 #include <vm/uma_int.h> 77 78 #include <machine/md_var.h> 79 #include <machine/vfp.h> 80 81 /* 82 * struct switchframe and trapframe must both be a multiple of 8 83 * for correct stack alignment. 84 */ 85 _Static_assert((sizeof(struct switchframe) % 8) == 0, "Bad alignment"); 86 _Static_assert((sizeof(struct trapframe) % 8) == 0, "Bad alignment"); 87 88 uint32_t initial_fpscr = VFPSCR_DN | VFPSCR_FZ; 89 90 /* 91 * Finish a fork operation, with process p2 nearly set up. 92 * Copy and update the pcb, set up the stack so that the child 93 * ready to run and return to user mode. 94 */ 95 void 96 cpu_fork(struct thread *td1, struct proc *p2, struct thread *td2, int flags) 97 { 98 struct pcb *pcb2; 99 struct trapframe *tf; 100 struct mdproc *mdp2; 101 102 if ((flags & RFPROC) == 0) 103 return; 104 105 /* Point the pcb to the top of the stack */ 106 pcb2 = (struct pcb *) 107 (td2->td_kstack + td2->td_kstack_pages * PAGE_SIZE) - 1; 108 #ifdef VFP 109 /* Store actual state of VFP */ 110 if (curthread == td1) { 111 critical_enter(); 112 vfp_store(&td1->td_pcb->pcb_vfpstate, false); 113 critical_exit(); 114 } 115 #endif 116 td2->td_pcb = pcb2; 117 118 /* Clone td1's pcb */ 119 bcopy(td1->td_pcb, pcb2, sizeof(*pcb2)); 120 121 /* Point to mdproc and then copy over td1's contents */ 122 mdp2 = &p2->p_md; 123 bcopy(&td1->td_proc->p_md, mdp2, sizeof(*mdp2)); 124 125 /* Point the frame to the stack in front of pcb and copy td1's frame */ 126 td2->td_frame = (struct trapframe *)pcb2 - 1; 127 *td2->td_frame = *td1->td_frame; 128 129 /* 130 * Create a new fresh stack for the new process. 131 * Copy the trap frame for the return to user mode as if from a 132 * syscall. This copies most of the user mode register values. 133 */ 134 pmap_set_pcb_pagedir(vmspace_pmap(p2->p_vmspace), pcb2); 135 pcb2->pcb_regs.sf_r4 = (register_t)fork_return; 136 pcb2->pcb_regs.sf_r5 = (register_t)td2; 137 pcb2->pcb_regs.sf_lr = (register_t)fork_trampoline; 138 pcb2->pcb_regs.sf_sp = STACKALIGN(td2->td_frame); 139 #if __ARM_ARCH >= 6 140 pcb2->pcb_regs.sf_tpidrurw = (register_t)get_tls(); 141 #endif 142 143 pcb2->pcb_vfpcpu = -1; 144 pcb2->pcb_vfpstate.fpscr = initial_fpscr; 145 146 tf = td2->td_frame; 147 tf->tf_spsr &= ~PSR_C; 148 tf->tf_r0 = 0; 149 tf->tf_r1 = 0; 150 151 152 /* Setup to release spin count in fork_exit(). */ 153 td2->td_md.md_spinlock_count = 1; 154 td2->td_md.md_saved_cspr = PSR_SVC32_MODE; 155 #if __ARM_ARCH < 6 156 td2->td_md.md_tp = *(register_t *)ARM_TP_ADDRESS; 157 #endif 158 } 159 160 void 161 cpu_thread_swapin(struct thread *td) 162 { 163 } 164 165 void 166 cpu_thread_swapout(struct thread *td) 167 { 168 } 169 170 void 171 cpu_set_syscall_retval(struct thread *td, int error) 172 { 173 struct trapframe *frame; 174 int fixup; 175 #ifdef __ARMEB__ 176 u_int call; 177 #endif 178 179 frame = td->td_frame; 180 fixup = 0; 181 182 #ifdef __ARMEB__ 183 /* 184 * __syscall returns an off_t while most other syscalls return an 185 * int. As an off_t is 64-bits and an int is 32-bits we need to 186 * place the returned data into r1. As the lseek and freebsd6_lseek 187 * syscalls also return an off_t they do not need this fixup. 188 */ 189 call = frame->tf_r7; 190 if (call == SYS___syscall) { 191 register_t *ap = &frame->tf_r0; 192 register_t code = ap[_QUAD_LOWWORD]; 193 fixup = (code != SYS_lseek); 194 } 195 #endif 196 197 switch (error) { 198 case 0: 199 if (fixup) { 200 frame->tf_r0 = 0; 201 frame->tf_r1 = td->td_retval[0]; 202 } else { 203 frame->tf_r0 = td->td_retval[0]; 204 frame->tf_r1 = td->td_retval[1]; 205 } 206 frame->tf_spsr &= ~PSR_C; /* carry bit */ 207 break; 208 case ERESTART: 209 /* 210 * Reconstruct the pc to point at the swi. 211 */ 212 #if __ARM_ARCH >= 7 213 if ((frame->tf_spsr & PSR_T) != 0) 214 frame->tf_pc -= THUMB_INSN_SIZE; 215 else 216 #endif 217 frame->tf_pc -= INSN_SIZE; 218 break; 219 case EJUSTRETURN: 220 /* nothing to do */ 221 break; 222 default: 223 frame->tf_r0 = SV_ABI_ERRNO(td->td_proc, error); 224 frame->tf_spsr |= PSR_C; /* carry bit */ 225 break; 226 } 227 } 228 229 /* 230 * Initialize machine state, mostly pcb and trap frame for a new 231 * thread, about to return to userspace. Put enough state in the new 232 * thread's PCB to get it to go back to the fork_return(), which 233 * finalizes the thread state and handles peculiarities of the first 234 * return to userspace for the new thread. 235 */ 236 void 237 cpu_copy_thread(struct thread *td, struct thread *td0) 238 { 239 240 bcopy(td0->td_frame, td->td_frame, sizeof(struct trapframe)); 241 bcopy(td0->td_pcb, td->td_pcb, sizeof(struct pcb)); 242 243 td->td_pcb->pcb_regs.sf_r4 = (register_t)fork_return; 244 td->td_pcb->pcb_regs.sf_r5 = (register_t)td; 245 td->td_pcb->pcb_regs.sf_lr = (register_t)fork_trampoline; 246 td->td_pcb->pcb_regs.sf_sp = STACKALIGN(td->td_frame); 247 248 td->td_frame->tf_spsr &= ~PSR_C; 249 td->td_frame->tf_r0 = 0; 250 251 /* Setup to release spin count in fork_exit(). */ 252 td->td_md.md_spinlock_count = 1; 253 td->td_md.md_saved_cspr = PSR_SVC32_MODE; 254 } 255 256 /* 257 * Set that machine state for performing an upcall that starts 258 * the entry function with the given argument. 259 */ 260 void 261 cpu_set_upcall(struct thread *td, void (*entry)(void *), void *arg, 262 stack_t *stack) 263 { 264 struct trapframe *tf = td->td_frame; 265 266 tf->tf_usr_sp = STACKALIGN((int)stack->ss_sp + stack->ss_size); 267 tf->tf_pc = (int)entry; 268 tf->tf_r0 = (int)arg; 269 tf->tf_spsr = PSR_USR32_MODE; 270 } 271 272 int 273 cpu_set_user_tls(struct thread *td, void *tls_base) 274 { 275 276 #if __ARM_ARCH >= 6 277 td->td_pcb->pcb_regs.sf_tpidrurw = (register_t)tls_base; 278 if (td == curthread) 279 set_tls(tls_base); 280 #else 281 td->td_md.md_tp = (register_t)tls_base; 282 if (td == curthread) { 283 critical_enter(); 284 *(register_t *)ARM_TP_ADDRESS = (register_t)tls_base; 285 critical_exit(); 286 } 287 #endif 288 return (0); 289 } 290 291 void 292 cpu_thread_exit(struct thread *td) 293 { 294 } 295 296 void 297 cpu_thread_alloc(struct thread *td) 298 { 299 td->td_pcb = (struct pcb *)(td->td_kstack + td->td_kstack_pages * 300 PAGE_SIZE) - 1; 301 /* 302 * Ensure td_frame is aligned to an 8 byte boundary as it will be 303 * placed into the stack pointer which must be 8 byte aligned in 304 * the ARM EABI. 305 */ 306 td->td_frame = (struct trapframe *)((caddr_t)td->td_pcb) - 1; 307 } 308 309 void 310 cpu_thread_free(struct thread *td) 311 { 312 } 313 314 void 315 cpu_thread_clean(struct thread *td) 316 { 317 } 318 319 /* 320 * Intercept the return address from a freshly forked process that has NOT 321 * been scheduled yet. 322 * 323 * This is needed to make kernel threads stay in kernel mode. 324 */ 325 void 326 cpu_fork_kthread_handler(struct thread *td, void (*func)(void *), void *arg) 327 { 328 td->td_pcb->pcb_regs.sf_r4 = (register_t)func; /* function */ 329 td->td_pcb->pcb_regs.sf_r5 = (register_t)arg; /* first arg */ 330 } 331 332 /* 333 * Software interrupt handler for queued VM system processing. 334 */ 335 void 336 swi_vm(void *dummy) 337 { 338 339 if (busdma_swi_pending) 340 busdma_swi(); 341 } 342 343 void 344 cpu_exit(struct thread *td) 345 { 346 } 347 348 bool 349 cpu_exec_vmspace_reuse(struct proc *p __unused, vm_map_t map __unused) 350 { 351 352 return (true); 353 } 354 355 int 356 cpu_procctl(struct thread *td __unused, int idtype __unused, id_t id __unused, 357 int com __unused, void *data __unused) 358 { 359 360 return (EINVAL); 361 } 362