1 /* $NetBSD: vm_machdep.c,v 1.79 2024/01/15 20:35:22 andvar Exp $ */ 2 3 /* 4 * Copyright (c) 1994-1998 Mark Brinicombe. 5 * Copyright (c) 1994 Brini. 6 * All rights reserved. 7 * 8 * This code is derived from software written for Brini by Mark Brinicombe 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by Brini. 21 * 4. The name of the company nor the name of the author may be used to 22 * endorse or promote products derived from this software without specific 23 * prior written permission. 24 * 25 * THIS SOFTWARE IS PROVIDED BY BRINI ``AS IS'' AND ANY EXPRESS OR IMPLIED 26 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 27 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 28 * IN NO EVENT SHALL BRINI OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, 29 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 30 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 31 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 35 * SUCH DAMAGE. 36 * 37 * RiscBSD kernel project 38 * 39 * vm_machdep.h 40 * 41 * vm machine specific bits 42 * 43 * Created : 08/10/94 44 */ 45 46 #include <sys/cdefs.h> 47 __KERNEL_RCSID(0, "$NetBSD: vm_machdep.c,v 1.79 2024/01/15 20:35:22 andvar Exp $"); 48 49 #include "opt_armfpe.h" 50 #include "opt_cputypes.h" 51 52 #include <sys/param.h> 53 54 #include <sys/buf.h> 55 #include <sys/cpu.h> 56 #include <sys/exec.h> 57 #include <sys/proc.h> 58 #ifdef STACKCHECKS 59 #include <sys/syslog.h> 60 #endif 61 #include <sys/systm.h> 62 #include <sys/vnode.h> 63 64 #include <uvm/uvm_extern.h> 65 66 #include <arm/vfpreg.h> 67 68 #include <machine/pcb.h> 69 #include <machine/pmap.h> 70 #include <machine/reg.h> 71 #include <machine/vmparam.h> 72 73 void lwp_trampoline(void); 74 75 /* 76 * Special compilation symbols: 77 * 78 * STACKCHECKS - Fill undefined and supervisor stacks with a known pattern 79 * on forking and check the pattern on exit, reporting 80 * the amount of stack used. 81 */ 82 83 void 84 cpu_proc_fork(struct proc *p1, struct proc *p2) 85 { 86 /* 87 * Copy machine arch string (it's small so just memcpy it). 88 */ 89 memcpy(p2->p_md.md_march, p1->p_md.md_march, sizeof(p2->p_md.md_march)); 90 } 91 92 /* 93 * Finish a fork operation, with LWP l2 nearly set up. 94 * 95 * Copy and update the pcb and trapframe, making the child ready to run. 96 * 97 * Rig the child's kernel stack so that it will start out in 98 * lwp_trampoline() which will call the specified func with the argument arg. 99 * 100 * If an alternate user-level stack is requested (with non-zero values 101 * in both the stack and stacksize args), set up the user stack pointer 102 * accordingly. 103 */ 104 void 105 cpu_lwp_fork(struct lwp *l1, struct lwp *l2, void *stack, size_t stacksize, 106 void (*func)(void *), void *arg) 107 { 108 struct switchframe *sf; 109 vaddr_t uv; 110 111 const struct pcb * const pcb1 = lwp_getpcb(l1); 112 struct pcb * const pcb2 = lwp_getpcb(l2); 113 114 #ifdef XXXDEBUG 115 printf("cpu_lwp_fork: %p %p %p %p\n", l1, l2, curlwp, &lwp0); 116 #endif /* DEBUG */ 117 118 /* Copy the pcb */ 119 *pcb2 = *pcb1; 120 121 #ifdef FPU_VFP 122 /* 123 * Disable the VFP for a newly created LWP but remember if the 124 * VFP state is valid. 125 */ 126 pcb2->pcb_vfp.vfp_fpexc &= ~VFP_FPEXC_EN; 127 #endif 128 129 /* 130 * Set up the kernel stack for the process. 131 * Note: this stack is not in use if we are forking from p1 132 */ 133 uv = uvm_lwp_getuarea(l2); 134 pcb2->pcb_ksp = uv + USPACE_SVC_STACK_TOP; 135 136 #ifdef STACKCHECKS 137 /* Fill the kernel stack with a known pattern */ 138 memset((void *)(uv + USPACE_SVC_STACK_BOTTOM), 0xdd, 139 (USPACE_SVC_STACK_TOP - USPACE_SVC_STACK_BOTTOM)); 140 #endif /* STACKCHECKS */ 141 142 #ifdef XXXDEBUG 143 printf("l1: pcb=%p pid=%d pmap=%p\n", 144 pcb1, l1->l_lid, l1->l_proc->p_vmspace->vm_map.pmap); 145 printf("l2: pcb=%p pid=%d pmap=%p\n", 146 pcb2, l2->l_lid, l2->l_proc->p_vmspace->vm_map.pmap); 147 #endif /* DEBUG */ 148 149 struct trapframe *tf = (struct trapframe *)pcb2->pcb_ksp - 1; 150 lwp_settrapframe(l2, tf); 151 *tf = *lwp_trapframe(l1); 152 153 /* 154 * If specified, give the child a different stack (make sure 155 * it's 8-byte aligned). 156 */ 157 if (stack != NULL) 158 tf->tf_usr_sp = ((vaddr_t)(stack) + stacksize) & -8; 159 160 sf = (struct switchframe *)tf - 1; 161 sf->sf_r4 = (u_int)func; 162 sf->sf_r5 = (u_int)arg; 163 sf->sf_r7 = PSR_USR32_MODE; /* for returning to userspace */ 164 sf->sf_sp = (u_int)tf; 165 sf->sf_pc = (u_int)lwp_trampoline; 166 pcb2->pcb_ksp = (u_int)sf; 167 } 168 169 /* 170 * cpu_exit is called as the last action during exit. 171 * 172 * We clean up a little and then call switch_exit() with the old proc as an 173 * argument. switch_exit() first switches to lwp0's context, and finally 174 * jumps into switch() to wait for another process to wake up. 175 */ 176 177 void 178 cpu_lwp_free(struct lwp *l, int proc) 179 { 180 #ifdef STACKCHECKS 181 /* Report how much stack has been used - debugging */ 182 struct pcb * const pcb = lwp_getpcb(l); 183 u_char *ptr; 184 u_int loop; 185 186 ptr = (u_char *)pcb + USPACE_SVC_STACK_BOTTOM; 187 for (loop = 0; loop < (USPACE_SVC_STACK_TOP - USPACE_SVC_STACK_BOTTOM) 188 && *ptr == 0xdd; ++loop, ++ptr) ; 189 log(LOG_INFO, "%u bytes of svc stack fill pattern\n", loop); 190 #endif /* STACKCHECKS */ 191 } 192 193 void 194 cpu_lwp_free2(struct lwp *l) 195 { 196 } 197 198 /* 199 * Map a user I/O request into kernel virtual address space. 200 * Note: the pages are already locked by uvm_vslock(), so we 201 * do not need to pass an access_type to pmap_enter(). 202 */ 203 int 204 vmapbuf(struct buf *bp, vsize_t len) 205 { 206 struct pmap * const pm = vm_map_pmap(&bp->b_proc->p_vmspace->vm_map); 207 vaddr_t faddr, taddr, off; 208 paddr_t fpa; 209 210 KASSERT(pm != pmap_kernel()); 211 212 #ifdef XXXDEBUG 213 printf("vmapbuf: bp=%08x buf=%08x len=%08x\n", (u_int)bp, 214 (u_int)bp->b_data, (u_int)len); 215 #endif /* XXXDEBUG */ 216 217 if ((bp->b_flags & B_PHYS) == 0) 218 panic("vmapbuf"); 219 220 bp->b_saveaddr = bp->b_data; 221 faddr = trunc_page((vaddr_t)bp->b_data); 222 off = (vaddr_t)bp->b_data - faddr; 223 len = round_page(off + len); 224 taddr = uvm_km_alloc(phys_map, len, atop(faddr) & uvmexp.colormask, 225 UVM_KMF_VAONLY | UVM_KMF_WAITVA | UVM_KMF_COLORMATCH); 226 bp->b_data = (void *)(taddr + off); 227 228 /* 229 * The region is locked, so we expect that pmap_extract() will return 230 * true. 231 */ 232 while (len) { 233 (void) pmap_extract(pm, faddr, &fpa); 234 pmap_enter(pmap_kernel(), taddr, fpa, VM_PROT_READ|VM_PROT_WRITE, 235 VM_PROT_READ|VM_PROT_WRITE|PMAP_WIRED); 236 faddr += PAGE_SIZE; 237 taddr += PAGE_SIZE; 238 len -= PAGE_SIZE; 239 } 240 pmap_update(pmap_kernel()); 241 242 return 0; 243 } 244 245 /* 246 * Unmap a previously-mapped user I/O request. 247 */ 248 void 249 vunmapbuf(struct buf *bp, vsize_t len) 250 { 251 vaddr_t addr, off; 252 253 #ifdef XXXDEBUG 254 printf("vunmapbuf: bp=%08x buf=%08x len=%08x\n", 255 (u_int)bp, (u_int)bp->b_data, (u_int)len); 256 #endif /* XXXDEBUG */ 257 258 if ((bp->b_flags & B_PHYS) == 0) 259 panic("vunmapbuf"); 260 261 /* 262 * Make sure the cache does not have dirty data for the 263 * pages we had mapped. 264 */ 265 addr = trunc_page((vaddr_t)bp->b_data); 266 off = (vaddr_t)bp->b_data - addr; 267 len = round_page(off + len); 268 269 pmap_remove(pmap_kernel(), addr, addr + len); 270 pmap_update(pmap_kernel()); 271 uvm_km_free(phys_map, addr, len, UVM_KMF_VAONLY); 272 bp->b_data = bp->b_saveaddr; 273 bp->b_saveaddr = 0; 274 } 275 276 void 277 ktext_write(void *to, const void *from, size_t size) 278 { 279 struct pmap *pmap = pmap_kernel(); 280 pd_entry_t *pde, oldpde, tmppde; 281 pt_entry_t *pte, oldpte, tmppte; 282 vaddr_t pgva; 283 size_t limit, savesize; 284 const char *src; 285 char *dst; 286 287 /* XXX: gcc */ 288 oldpte = 0; 289 290 if ((savesize = size) == 0) 291 return; 292 293 dst = (char *) to; 294 src = (const char *) from; 295 296 do { 297 /* Get the PDE of the current VA. */ 298 if (pmap_get_pde_pte(pmap, (vaddr_t) dst, &pde, &pte) == false) 299 goto no_mapping; 300 switch ((oldpde = *pde) & L1_TYPE_MASK) { 301 case L1_TYPE_S: 302 pgva = (vaddr_t)dst & L1_S_FRAME; 303 limit = L1_S_SIZE - ((vaddr_t)dst & L1_S_OFFSET); 304 305 tmppde = l1pte_set_writable(oldpde); 306 *pde = tmppde; 307 PTE_SYNC(pde); 308 break; 309 310 case L1_TYPE_C: 311 pgva = (vaddr_t)dst & L2_S_FRAME; 312 limit = L2_S_SIZE - ((vaddr_t)dst & L2_S_OFFSET); 313 314 if (pte == NULL) 315 goto no_mapping; 316 oldpte = *pte; 317 tmppte = l2pte_set_writable(oldpte); 318 *pte = tmppte; 319 PTE_SYNC(pte); 320 break; 321 322 default: 323 no_mapping: 324 printf(" address 0x%08lx not a valid page\n", 325 (vaddr_t) dst); 326 return; 327 } 328 cpu_tlb_flushD_SE(pgva); 329 cpu_cpwait(); 330 331 if (limit > size) 332 limit = size; 333 size -= limit; 334 335 /* 336 * Page is now writable. Do as much access as we 337 * can in this page. 338 */ 339 for (; limit > 0; limit--) 340 *dst++ = *src++; 341 342 /* 343 * Restore old mapping permissions. 344 */ 345 switch (oldpde & L1_TYPE_MASK) { 346 case L1_TYPE_S: 347 *pde = oldpde; 348 PTE_SYNC(pde); 349 break; 350 351 case L1_TYPE_C: 352 *pte = oldpte; 353 PTE_SYNC(pte); 354 break; 355 } 356 cpu_tlb_flushD_SE(pgva); 357 cpu_cpwait(); 358 } while (size != 0); 359 360 /* Sync the I-cache. */ 361 cpu_icache_sync_range((vaddr_t)to, savesize); 362 } 363 364 /* End of vm_machdep.c */ 365
Indexes created Sun Sep 21 19:09:51 GMT 2025