1 /* $NetBSD: vm_machdep.c,v 1.102 2019/02/11 07:51:46 macallan Exp $ */ 2 3 /* 4 * Copyright (c) 1996-2002 Eduardo Horvath. All rights reserved. 5 * Copyright (c) 1996 6 * The President and Fellows of Harvard College. All rights reserved. 7 * Copyright (c) 1992, 1993 8 * The Regents of the University of California. All rights reserved. 9 * 10 * This software was developed by the Computer Systems Engineering group 11 * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and 12 * contributed to Berkeley. 13 * 14 * All advertising materials mentioning features or use of this software 15 * must display the following acknowledgement: 16 * This product includes software developed by the University of 17 * California, Lawrence Berkeley Laboratory. 18 * This product includes software developed by Harvard University. 19 * 20 * Redistribution and use in source and binary forms, with or without 21 * modification, are permitted provided that the following conditions 22 * are met: 23 * 1. Redistributions of source code must retain the above copyright 24 * notice, this list of conditions and the following disclaimer. 25 * 2. Redistributions in binary form must reproduce the above copyright 26 * notice, this list of conditions and the following disclaimer in the 27 * documentation and/or other materials provided with the distribution. 28 * 3. All advertising materials mentioning features or use of this software 29 * must display the following acknowledgement: 30 * This product includes software developed by Harvard University. 31 * This product includes software developed by the University of 32 * California, Berkeley and its contributors. 33 * 4. Neither the name of the University nor the names of its contributors 34 * may be used to endorse or promote products derived from this software 35 * without specific prior written permission. 36 * 37 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 38 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 39 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 40 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 41 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 42 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 43 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 44 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 45 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 46 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 47 * SUCH DAMAGE. 48 * 49 * @(#)vm_machdep.c 8.2 (Berkeley) 9/23/93 50 */ 51 52 #include <sys/cdefs.h> 53 __KERNEL_RCSID(0, "$NetBSD: vm_machdep.c,v 1.102 2019/02/11 07:51:46 macallan Exp $"); 54 55 #include "opt_multiprocessor.h" 56 57 #include <sys/param.h> 58 #include <sys/systm.h> 59 #include <sys/proc.h> 60 #include <sys/core.h> 61 #include <sys/buf.h> 62 #include <sys/exec.h> 63 #include <sys/vnode.h> 64 #include <sys/cpu.h> 65 66 #include <uvm/uvm_extern.h> 67 68 #include <machine/cpu.h> 69 #include <machine/frame.h> 70 #include <machine/pcb.h> 71 #include <machine/trap.h> 72 #include <sys/bus.h> 73 74 /* 75 * Map a user I/O request into kernel virtual address space. 76 * Note: the pages are already locked by uvm_vslock(), so we 77 * do not need to pass an access_type to pmap_enter(). 78 */ 79 int 80 vmapbuf(struct buf *bp, vsize_t len) 81 { 82 struct pmap *upmap; 83 vaddr_t uva; /* User VA (map from) */ 84 vaddr_t kva; /* Kernel VA (new to) */ 85 paddr_t pa; /* physical address */ 86 vsize_t off; 87 88 if ((bp->b_flags & B_PHYS) == 0) 89 panic("vmapbuf"); 90 91 bp->b_saveaddr = bp->b_data; 92 uva = trunc_page((vaddr_t)bp->b_data); 93 off = (vaddr_t)bp->b_data - uva; 94 len = round_page(off + len); 95 kva = uvm_km_alloc(kernel_map, len, 0, UVM_KMF_VAONLY | UVM_KMF_WAITVA); 96 bp->b_data = (void *)(kva + off); 97 98 upmap = vm_map_pmap(&bp->b_proc->p_vmspace->vm_map); 99 do { 100 if (pmap_extract(upmap, uva, &pa) == FALSE) 101 panic("vmapbuf: null page frame"); 102 /* Now map the page into kernel space. */ 103 pmap_kenter_pa(kva, pa, VM_PROT_READ | VM_PROT_WRITE, 0); 104 105 uva += PAGE_SIZE; 106 kva += PAGE_SIZE; 107 len -= PAGE_SIZE; 108 } while (len); 109 pmap_update(pmap_kernel()); 110 111 return 0; 112 } 113 114 /* 115 * Unmap a previously-mapped user I/O request. 116 */ 117 void 118 vunmapbuf(struct buf *bp, vsize_t len) 119 { 120 vaddr_t kva; 121 vsize_t off; 122 123 if ((bp->b_flags & B_PHYS) == 0) 124 panic("vunmapbuf"); 125 126 kva = trunc_page((vaddr_t)bp->b_data); 127 off = (vaddr_t)bp->b_data - kva; 128 len = round_page(off + len); 129 pmap_kremove(kva, len); 130 uvm_km_free(kernel_map, kva, len, UVM_KMF_VAONLY); 131 bp->b_data = bp->b_saveaddr; 132 bp->b_saveaddr = NULL; 133 } 134 135 void 136 cpu_proc_fork(struct proc *p1, struct proc *p2) 137 { 138 139 p2->p_md.md_flags = p1->p_md.md_flags; 140 } 141 142 143 /* 144 * The offset of the topmost frame in the kernel stack. 145 */ 146 #ifdef __arch64__ 147 #define TOPFRAMEOFF (USPACE-sizeof(struct trapframe)-CC64FSZ) 148 #define STACK_OFFSET BIAS 149 #else 150 #undef trapframe 151 #define trapframe trapframe64 152 #undef rwindow 153 #define rwindow rwindow32 154 #define TOPFRAMEOFF (USPACE-sizeof(struct trapframe)-CC64FSZ) 155 #define STACK_OFFSET 0 156 #endif 157 158 #ifdef DEBUG 159 char cpu_forkname[] = "cpu_lwp_fork()"; 160 #endif 161 162 /* 163 * Finish a fork operation, with lwp l2 nearly set up. 164 * Copy and update the pcb and trap frame, making the child ready to run. 165 * 166 * Rig the child's kernel stack so that it will start out in 167 * lwp_trampoline() and call child_return() with l2 as an 168 * argument. This causes the newly-created child process to go 169 * directly to user level with an apparent return value of 0 from 170 * fork(), while the parent process returns normally. 171 * 172 * l1 is the process being forked; if l1 == &lwp0, we are creating 173 * a kernel thread, and the return path and argument are specified with 174 * `func' and `arg'. 175 * 176 * If an alternate user-level stack is requested (with non-zero values 177 * in both the stack and stacksize args), set up the user stack pointer 178 * accordingly. 179 */ 180 void lwp_trampoline(void); 181 void 182 cpu_lwp_fork(register struct lwp *l1, register struct lwp *l2, void *stack, size_t stacksize, void (*func)(void *), void *arg) 183 { 184 struct pcb *opcb = lwp_getpcb(l1); 185 struct pcb *npcb = lwp_getpcb(l2); 186 struct trapframe *tf2; 187 struct rwindow *rp; 188 189 /* 190 * Save all user registers to l1's stack or, in the case of 191 * user registers and invalid stack pointers, to opcb. 192 * We then copy the whole pcb to l2; when switch() selects l2 193 * to run, it will run at the `lwp_trampoline' stub, rather 194 * than returning at the copying code below. 195 * 196 * If process l1 has an FPU state, we must copy it. If it is 197 * the FPU user, we must save the FPU state first. 198 */ 199 200 #ifdef NOTDEF_DEBUG 201 printf("cpu_lwp_fork()\n"); 202 #endif 203 if (l1 == curlwp) { 204 write_user_windows(); 205 206 /* 207 * We're in the kernel, so we don't really care about 208 * %ccr or %asi. We do want to duplicate %pstate and %cwp. 209 */ 210 opcb->pcb_pstate = getpstate(); 211 opcb->pcb_cwp = getcwp(); 212 } 213 #ifdef DIAGNOSTIC 214 else if (l1 != &lwp0) 215 panic("cpu_lwp_fork: curlwp"); 216 #endif 217 #ifdef DEBUG 218 /* prevent us from having NULL lastcall */ 219 opcb->lastcall = cpu_forkname; 220 #else 221 opcb->lastcall = NULL; 222 #endif 223 memcpy(npcb, opcb, sizeof(struct pcb)); 224 if (l1->l_md.md_fpstate) { 225 fpusave_lwp(l1, true); 226 l2->l_md.md_fpstate = pool_cache_get(fpstate_cache, PR_WAITOK); 227 memcpy(l2->l_md.md_fpstate, l1->l_md.md_fpstate, 228 sizeof(struct fpstate64)); 229 } else 230 l2->l_md.md_fpstate = NULL; 231 232 /* 233 * Setup (kernel) stack frame that will by-pass the child 234 * out of the kernel. (The trap frame invariably resides at 235 * the tippity-top of the u. area.) 236 */ 237 tf2 = l2->l_md.md_tf = (struct trapframe *) 238 ((long)npcb + USPACE - sizeof(*tf2)); 239 240 /* Copy parent's trapframe */ 241 *tf2 = *(struct trapframe *)((long)opcb + USPACE - sizeof(*tf2)); 242 243 /* 244 * If specified, give the child a different stack. 245 */ 246 if (stack != NULL) 247 tf2->tf_out[6] = (uint64_t)(u_long)stack + stacksize; 248 249 /* 250 * Need to create a %tstate if we are forking our first userland 251 * process - in all other cases we inherit from the parent. 252 */ 253 if (l2->l_proc->p_pid == 1) 254 tf2->tf_tstate = (ASI_PRIMARY_NO_FAULT<<TSTATE_ASI_SHIFT) | 255 ((PSTATE_USER)<<TSTATE_PSTATE_SHIFT); 256 257 /* 258 * Set return values in child mode and clear condition code, 259 * in case we end up running a signal handler before returning 260 * to userland. 261 */ 262 tf2->tf_out[0] = 0; 263 tf2->tf_out[1] = 1; 264 tf2->tf_tstate &= ~TSTATE_CCR; 265 266 /* Construct kernel frame to return to in cpu_switch() */ 267 rp = (struct rwindow *)((u_long)npcb + TOPFRAMEOFF); 268 *rp = *(struct rwindow *)((u_long)opcb + TOPFRAMEOFF); 269 270 rp->rw_local[0] = (long)func; /* Function to call */ 271 rp->rw_local[1] = (long)arg; /* and its argument */ 272 rp->rw_local[2] = (long)l2; /* new lwp */ 273 274 npcb->pcb_pc = (long)lwp_trampoline - 8; 275 npcb->pcb_sp = (long)rp - STACK_OFFSET; 276 } 277 278 static inline void 279 fpusave_cpu(bool save) 280 { 281 struct lwp *l = fplwp; 282 283 if (l == NULL) 284 return; 285 286 if (save) 287 savefpstate(l->l_md.md_fpstate); 288 else 289 clearfpstate(); 290 291 fplwp = NULL; 292 } 293 294 void 295 fpusave_lwp(struct lwp *l, bool save) 296 { 297 #ifdef MULTIPROCESSOR 298 volatile struct cpu_info *ci; 299 300 if (l == fplwp) { 301 int s = intr_disable(); 302 fpusave_cpu(save); 303 intr_restore(s); 304 return; 305 } 306 307 for (ci = cpus; ci != NULL; ci = ci->ci_next) { 308 int spincount, retrycount=0; 309 310 if (ci == curcpu() || !CPUSET_HAS(cpus_active, ci->ci_index)) 311 continue; 312 if (ci->ci_fplwp != l) 313 continue; 314 again: 315 sparc64_send_ipi(ci->ci_cpuid, save ? 316 sparc64_ipi_save_fpstate : 317 sparc64_ipi_drop_fpstate, (uintptr_t)l, 0); 318 319 spincount = 0; 320 while (ci->ci_fplwp == l) { 321 membar_Sync(); 322 spincount++; 323 if (spincount > 10000000) { 324 printf("fpusave_lwp ipi didn't (%d)\n", retrycount); 325 retrycount++; 326 goto again; 327 } 328 } 329 if (retrycount > 0) printf("spincount %d\n", spincount); 330 break; 331 } 332 #else 333 if (l == fplwp) 334 fpusave_cpu(save); 335 #endif 336 } 337 338 339 void 340 cpu_lwp_free(struct lwp *l, int proc) 341 { 342 343 if (l->l_md.md_fpstate != NULL) 344 fpusave_lwp(l, false); 345 } 346 347 void 348 cpu_lwp_free2(struct lwp *l) 349 { 350 struct fpstate64 *fs; 351 352 if ((fs = l->l_md.md_fpstate) != NULL) 353 pool_cache_put(fpstate_cache, fs); 354 } 355 356 int 357 cpu_lwp_setprivate(lwp_t *l, void *addr) 358 { 359 struct trapframe *tf = l->l_md.md_tf; 360 361 tf->tf_global[7] = (uintptr_t)addr; 362 363 return 0; 364 } 365
Indexes created Fri Sep 26 08:10:20 GMT 2025