1 /* $NetBSD: vm_machdep.c,v 1.101 2009/11/21 04:16:52 rmind Exp $ */ 2 3 /* 4 * Copyright (c) 1996 5 * The President and Fellows of Harvard College. All rights reserved. 6 * Copyright (c) 1992, 1993 7 * The Regents of the University of California. All rights reserved. 8 * 9 * This software was developed by the Computer Systems Engineering group 10 * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and 11 * contributed to Berkeley. 12 * 13 * All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Lawrence Berkeley Laboratory. 17 * This product includes software developed by Harvard University. 18 * 19 * Redistribution and use in source and binary forms, with or without 20 * modification, are permitted provided that the following conditions 21 * are met: 22 * 1. Redistributions of source code must retain the above copyright 23 * notice, this list of conditions and the following disclaimer. 24 * 2. Redistributions in binary form must reproduce the above copyright 25 * notice, this list of conditions and the following disclaimer in the 26 * documentation and/or other materials provided with the distribution. 27 * 3. All advertising materials mentioning features or use of this software 28 * must display the following acknowledgement: 29 * This product includes software developed by Harvard University. 30 * This product includes software developed by the University of 31 * California, Berkeley and its contributors. 32 * 4. Neither the name of the University nor the names of its contributors 33 * may be used to endorse or promote products derived from this software 34 * without specific prior written permission. 35 * 36 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 37 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 38 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 39 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 40 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 41 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 42 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 43 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 44 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 45 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 46 * SUCH DAMAGE. 47 * 48 * @(#)vm_machdep.c 8.2 (Berkeley) 9/23/93 49 */ 50 51 #include <sys/cdefs.h> 52 __KERNEL_RCSID(0, "$NetBSD: vm_machdep.c,v 1.101 2009/11/21 04:16:52 rmind Exp $"); 53 54 #include "opt_multiprocessor.h" 55 56 #include <sys/param.h> 57 #include <sys/systm.h> 58 #include <sys/proc.h> 59 #include <sys/core.h> 60 #include <sys/malloc.h> 61 #include <sys/buf.h> 62 #include <sys/exec.h> 63 #include <sys/vnode.h> 64 #include <sys/simplelock.h> 65 66 #include <uvm/uvm_extern.h> 67 68 #include <machine/cpu.h> 69 #include <machine/frame.h> 70 #include <machine/trap.h> 71 72 #include <sparc/sparc/cpuvar.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 void 80 vmapbuf(struct buf *bp, vsize_t len) 81 { 82 struct pmap *upmap, *kpmap; 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 /* 92 * XXX: It might be better to round/trunc to a 93 * segment boundary to avoid VAC problems! 94 */ 95 bp->b_saveaddr = bp->b_data; 96 uva = trunc_page((vaddr_t)bp->b_data); 97 off = (vaddr_t)bp->b_data - uva; 98 len = round_page(off + len); 99 kva = uvm_km_alloc(kernel_map, len, 0, UVM_KMF_VAONLY | UVM_KMF_WAITVA); 100 bp->b_data = (void *)(kva + off); 101 102 /* 103 * We have to flush any write-back cache on the 104 * user-space mappings so our new mappings will 105 * have the correct contents. 106 */ 107 if (CACHEINFO.c_vactype != VAC_NONE) 108 cache_flush((void *)uva, len); 109 110 upmap = vm_map_pmap(&bp->b_proc->p_vmspace->vm_map); 111 kpmap = vm_map_pmap(kernel_map); 112 do { 113 if (pmap_extract(upmap, uva, &pa) == false) 114 panic("vmapbuf: null page frame"); 115 /* Now map the page into kernel space. */ 116 pmap_enter(kpmap, kva, pa, 117 VM_PROT_READ|VM_PROT_WRITE, PMAP_WIRED); 118 uva += PAGE_SIZE; 119 kva += PAGE_SIZE; 120 len -= PAGE_SIZE; 121 } while (len); 122 pmap_update(kpmap); 123 } 124 125 /* 126 * Unmap a previously-mapped user I/O request. 127 */ 128 void 129 vunmapbuf(struct buf *bp, vsize_t len) 130 { 131 vaddr_t kva; 132 vsize_t off; 133 134 if ((bp->b_flags & B_PHYS) == 0) 135 panic("vunmapbuf"); 136 137 kva = trunc_page((vaddr_t)bp->b_data); 138 off = (vaddr_t)bp->b_data - kva; 139 len = round_page(off + len); 140 pmap_remove(vm_map_pmap(kernel_map), kva, kva + len); 141 pmap_update(vm_map_pmap(kernel_map)); 142 uvm_km_free(kernel_map, kva, len, UVM_KMF_VAONLY); 143 bp->b_data = bp->b_saveaddr; 144 bp->b_saveaddr = NULL; 145 146 #if 0 /* XXX: The flush above is sufficient, right? */ 147 if (CACHEINFO.c_vactype != VAC_NONE) 148 cpuinfo.cache_flush(bp->b_data, len); 149 #endif 150 } 151 152 153 void 154 cpu_proc_fork(struct proc *p1, struct proc *p2) 155 { 156 157 p2->p_md.md_flags = p1->p_md.md_flags; 158 } 159 160 161 /* 162 * The offset of the topmost frame in the kernel stack. 163 */ 164 #define TOPFRAMEOFF (USPACE-sizeof(struct trapframe)-sizeof(struct frame)) 165 166 /* 167 * Finish a fork operation, with process l2 nearly set up. 168 * Copy and update the pcb and trap frame, making the child ready to run. 169 * 170 * Rig the child's kernel stack so that it will start out in 171 * lwp_trampoline() and call child_return() with l2 as an 172 * argument. This causes the newly-created child process to go 173 * directly to user level with an apparent return value of 0 from 174 * fork(), while the parent process returns normally. 175 * 176 * l1 is the process being forked; if l1 == &lwp0, we are creating 177 * a kernel thread, and the return path and argument are specified with 178 * `func' and `arg'. 179 * 180 * If an alternate user-level stack is requested (with non-zero values 181 * in both the stack and stacksize args), set up the user stack pointer 182 * accordingly. 183 */ 184 void 185 cpu_lwp_fork(struct lwp *l1, struct lwp *l2, 186 void *stack, size_t stacksize, 187 void (*func)(void *), void *arg) 188 { 189 struct pcb *opcb = lwp_getpcb(l1); 190 struct pcb *npcb = lwp_getpcb(l2); 191 struct trapframe *tf2; 192 struct rwindow *rp; 193 194 /* 195 * Save all user registers to l1's stack or, in the case of 196 * user registers and invalid stack pointers, to opcb. 197 * We then copy the whole pcb to l2; when switch() selects l2 198 * to run, it will run at the `lwp_trampoline' stub, rather 199 * than returning at the copying code below. 200 * 201 * If process l1 has an FPU state, we must copy it. If it is 202 * the FPU user, we must save the FPU state first. 203 */ 204 205 if (l1 == curlwp) { 206 write_user_windows(); 207 opcb->pcb_psr = getpsr(); 208 } 209 #ifdef DIAGNOSTIC 210 else if (l1 != &lwp0) /* XXX is this valid? */ 211 panic("cpu_lwp_fork: curlwp"); 212 #endif 213 214 memcpy((void *)npcb, (void *)opcb, sizeof(struct pcb)); 215 if (l1->l_md.md_fpstate != NULL) { 216 struct cpu_info *cpi; 217 int s; 218 219 l2->l_md.md_fpstate = malloc(sizeof(struct fpstate), 220 M_SUBPROC, M_WAITOK); 221 222 FPU_LOCK(s); 223 if ((cpi = l1->l_md.md_fpu) != NULL) { 224 if (cpi->fplwp != l1) 225 panic("FPU(%d): fplwp %p", 226 cpi->ci_cpuid, cpi->fplwp); 227 if (l1 == cpuinfo.fplwp) 228 savefpstate(l1->l_md.md_fpstate); 229 #if defined(MULTIPROCESSOR) 230 else 231 XCALL1(savefpstate, l1->l_md.md_fpstate, 232 1 << cpi->ci_cpuid); 233 #endif 234 } 235 memcpy(l2->l_md.md_fpstate, l1->l_md.md_fpstate, 236 sizeof(struct fpstate)); 237 FPU_UNLOCK(s); 238 } else 239 l2->l_md.md_fpstate = NULL; 240 241 l2->l_md.md_fpu = NULL; 242 243 /* 244 * Setup (kernel) stack frame that will by-pass the child 245 * out of the kernel. (The trap frame invariably resides at 246 * the tippity-top of the u. area.) 247 */ 248 tf2 = l2->l_md.md_tf = (struct trapframe *) 249 ((int)npcb + USPACE - sizeof(*tf2)); 250 251 /* Copy parent's trapframe */ 252 *tf2 = *(struct trapframe *)((int)opcb + USPACE - sizeof(*tf2)); 253 254 /* 255 * If specified, give the child a different stack. 256 */ 257 if (stack != NULL) 258 tf2->tf_out[6] = (u_int)stack + stacksize; 259 260 /* 261 * The fork system call always uses the old system call 262 * convention; clear carry and skip trap instruction as 263 * in syscall(). 264 * note: lwp_trampoline() sets a fresh psr when returning 265 * to user mode. 266 */ 267 /*tf2->tf_psr &= ~PSR_C; -* success */ 268 tf2->tf_pc = tf2->tf_npc; 269 tf2->tf_npc = tf2->tf_pc + 4; 270 271 /* Set return values in child mode */ 272 tf2->tf_out[0] = 0; 273 tf2->tf_out[1] = 1; 274 275 /* Construct kernel frame to return to in cpu_switch() */ 276 rp = (struct rwindow *)((u_int)npcb + TOPFRAMEOFF); 277 /**rp = *(struct rwindow *)((u_int)opcb + TOPFRAMEOFF);*/ 278 rp->rw_local[0] = (int)func; /* Function to call */ 279 rp->rw_local[1] = (int)arg; /* and its argument */ 280 rp->rw_local[2] = (int)l2; /* new LWP */ 281 282 npcb->pcb_pc = (int)lwp_trampoline - 8; 283 npcb->pcb_sp = (int)rp; 284 npcb->pcb_psr &= ~PSR_CWP; /* Run in window #0 */ 285 npcb->pcb_wim = 1; /* Fence at window #1 */ 286 } 287 288 /* 289 * Cleanup FPU state. 290 */ 291 void 292 cpu_lwp_free(struct lwp *l, int proc) 293 { 294 struct fpstate *fs; 295 296 if ((fs = l->l_md.md_fpstate) != NULL) { 297 struct cpu_info *cpi; 298 int s; 299 300 FPU_LOCK(s); 301 if ((cpi = l->l_md.md_fpu) != NULL) { 302 if (cpi->fplwp != l) 303 panic("FPU(%d): fplwp %p", 304 cpi->ci_cpuid, cpi->fplwp); 305 if (l == cpuinfo.fplwp) 306 savefpstate(fs); 307 #if defined(MULTIPROCESSOR) 308 else 309 XCALL1(savefpstate, fs, 1 << cpi->ci_cpuid); 310 #endif 311 cpi->fplwp = NULL; 312 } 313 l->l_md.md_fpu = NULL; 314 FPU_UNLOCK(s); 315 } 316 } 317 318 void 319 cpu_lwp_free2(struct lwp *l) 320 { 321 struct fpstate *fs; 322 323 if ((fs = l->l_md.md_fpstate) != NULL) 324 free((void *)fs, M_SUBPROC); 325 } 326 327 void 328 cpu_setfunc(struct lwp *l, void (*func)(void *), void *arg) 329 { 330 struct pcb *pcb = lwp_getpcb(l); 331 /*struct trapframe *tf = l->l_md.md_tf;*/ 332 struct rwindow *rp; 333 334 /* Construct kernel frame to return to in cpu_switch() */ 335 rp = (struct rwindow *)((u_int)pcb + TOPFRAMEOFF); 336 rp->rw_local[0] = (int)func; /* Function to call */ 337 rp->rw_local[1] = (int)arg; /* and its argument */ 338 339 pcb->pcb_pc = (int)lwp_setfunc_trampoline - 8; 340 pcb->pcb_sp = (int)rp; 341 pcb->pcb_psr &= ~PSR_CWP; /* Run in window #0 */ 342 pcb->pcb_wim = 1; /* Fence at window #1 */ 343 } 344