1 /* $NetBSD: pmap_bootstrap.c,v 1.43 2026/04/05 14:35:48 thorpej Exp $ */ 2 3 /* 4 * Copyright (c) 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * the Systems Programming Group of the University of Utah Computer 9 * Science Department. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 * 35 * @(#)pmap_bootstrap.c 8.1 (Berkeley) 6/10/93 36 */ 37 38 #include <sys/cdefs.h> 39 __KERNEL_RCSID(0, "$NetBSD: pmap_bootstrap.c,v 1.43 2026/04/05 14:35:48 thorpej Exp $"); 40 41 #include <sys/param.h> 42 #include <uvm/uvm_extern.h> 43 44 #include <machine/cpu.h> 45 #include <machine/pte.h> 46 #include <machine/vmparam.h> 47 48 #define RELOC(v, t) *((t*)((uintptr_t)&(v) + firstpa - KERNBASE)) 49 50 extern char *etext; 51 extern paddr_t avail_start, avail_end; 52 extern vaddr_t kernel_reloc_offset; 53 54 /* 55 * Special purpose kernel virtual addresses, used for mapping 56 * physical pages for a variety of temporary or permanent purposes: 57 * 58 * CADDR1, CADDR2: pmap zero/copy operations 59 * vmmap: /dev/mem, crash dumps, parity error checking 60 * msgbufaddr: kernel message buffer 61 */ 62 void *CADDR1, *CADDR2; 63 char *vmmap; 64 extern void *msgbufaddr; 65 66 paddr_t pmap_bootstrap1(paddr_t, paddr_t); 67 68 /* 69 * Bootstrap the VM system. 70 * 71 * Called with MMU off so we must relocate all global references by `firstpa' 72 * (don't call any functions here!) `nextpa' is the first available physical 73 * memory address. Returns an updated first PA reflecting the memory we 74 * have allocated. MMU is still off when we return. 75 * 76 * XXX assumes sizeof(u_int) == sizeof(pt_entry_t) 77 * XXX a PIC compiler would make this much easier. 78 */ 79 paddr_t __attribute__((no_instrument_function)) 80 pmap_bootstrap1(paddr_t nextpa, paddr_t firstpa) 81 { 82 paddr_t lwp0upa, kstpa, kptmpa, kptpa; 83 paddr_t lkptpa; 84 u_int nptpages, kstsize; 85 st_entry_t protoste, *ste, *este; 86 pt_entry_t protopte, *pte, *epte; 87 u_int stfree = 0; /* XXX: gcc -Wuninitialized */ 88 89 nextpa = m68k_round_page(nextpa); 90 91 /* 92 * Calculate important physical addresses: 93 * 94 * lwp0upa lwp0 u-area UPAGES pages 95 * 96 * kstpa kernel segment table 1 page (!040) 97 * N pages (040) 98 * 99 * kptmpa kernel PT map 1 page 100 * 101 * lkptpa last kernel PT page 1 page 102 * 103 * kptpa statically allocated 104 * kernel PT pages Sysptsize+ pages 105 * 106 * [ Sysptsize is the number of pages of PT, and IIOMAPSIZE and 107 * EIOMAPSIZE are the number of PTEs, hence we need to round 108 * the total to a page boundary with IO maps at the end. ] 109 * 110 * The KVA corresponding to any of these PAs is: 111 * (PA - firstpa + KERNBASE). 112 */ 113 RELOC(kernel_reloc_offset, vaddr_t) = firstpa; 114 115 lwp0upa = nextpa; 116 nextpa += USPACE; 117 if (RELOC(mmutype, int) == MMU_68040) 118 kstsize = MAXKL2SIZE / (NPTEPG/SG4_LEV2SIZE); 119 else 120 kstsize = 1; 121 kstpa = nextpa; 122 nextpa += kstsize * PAGE_SIZE; 123 kptmpa = nextpa; 124 nextpa += PAGE_SIZE; 125 lkptpa = nextpa; 126 nextpa += PAGE_SIZE; 127 kptpa = nextpa; 128 nptpages = RELOC(Sysptsize, int) + 129 howmany(RELOC(physmem, psize_t), NPTEPG); 130 nextpa += nptpages * PAGE_SIZE; 131 132 /* 133 * Initialize segment table and kernel page table map. 134 * 135 * On 68030s and earlier MMUs the two are identical except for 136 * the valid bits so both are initialized with essentially the 137 * same values. On the 68040, which has a mandatory 3-level 138 * structure, the segment table holds the level 1 table and part 139 * (or all) of the level 2 table and hence is considerably 140 * different. Here the first level consists of 128 descriptors 141 * (512 bytes) each mapping 32mb of address space. Each of these 142 * points to blocks of 128 second level descriptors (512 bytes) 143 * each mapping 256kb. Note that there may be additional "segment 144 * table" pages depending on how large MAXKL2SIZE is. 145 * 146 * Portions of the last two segment of KVA space (0xFF800000 - 147 * 0xFFFFFFFF) are mapped for a couple of purposes. 148 * The first segment (0xFF800000 - 0xFFBFFFFF) is mapped 149 * for the kernel page tables. 150 * 151 * XXX: It looks this was copied from hp300 and not sure if 152 * XXX: last physical page mapping is really needed on this port. 153 * The very last page (0xFFFFF000) in the second segment is mapped 154 * to the last physical page of RAM to give us a region in which 155 * PA == VA. We use the first part of this page for enabling 156 * and disabling mapping. The last part of this page also contains 157 * info left by the boot ROM. 158 * 159 * XXX cramming two levels of mapping into the single "segment" 160 * table on the 68040 is intended as a temporary hack to get things 161 * working. The 224mb of address space that this allows will most 162 * likely be insufficient in the future (at least for the kernel). 163 */ 164 if (RELOC(mmutype, int) == MMU_68040) { 165 int nl1desc, nl2desc, i; 166 167 /* 168 * First invalidate the entire "segment table" pages 169 * (levels 1 and 2 have the same "invalid" value). 170 */ 171 ste = (st_entry_t *)kstpa; 172 este = &ste[kstsize * NPTEPG]; 173 while (ste < este) 174 *ste++ = SG_NV; 175 /* 176 * Initialize level 2 descriptors (which immediately 177 * follow the level 1 table). We need: 178 * NPTEPG / SG4_LEV3SIZE 179 * level 2 descriptors to map each of the nptpages 180 * pages of PTEs. Note that we set the "used" bit 181 * now to save the HW the expense of doing it. 182 */ 183 nl2desc = nptpages * (NPTEPG / SG4_LEV3SIZE); 184 ste = (st_entry_t *)kstpa; 185 ste = &ste[SG4_LEV1SIZE]; 186 este = &ste[nl2desc]; 187 protoste = kptpa | SG_U | SG_RW | SG_V; 188 while (ste < este) { 189 *ste++ = protoste; 190 protoste += (SG4_LEV3SIZE * sizeof(st_entry_t)); 191 } 192 /* 193 * Initialize level 1 descriptors. We need: 194 * howmany(nl2desc, SG4_LEV2SIZE) 195 * level 1 descriptors to map the `nl2desc' level 2's. 196 */ 197 nl1desc = howmany(nl2desc, SG4_LEV2SIZE); 198 ste = (st_entry_t *)kstpa; 199 este = &ste[nl1desc]; 200 protoste = (paddr_t)&ste[SG4_LEV1SIZE] | SG_U | SG_RW | SG_V; 201 while (ste < este) { 202 *ste++ = protoste; 203 protoste += (SG4_LEV2SIZE * sizeof(st_entry_t)); 204 } 205 /* 206 * Initialize the final level 1 descriptor to map the next 207 * block of level 2 descriptors for Sysptmap. 208 */ 209 ste = (st_entry_t *)kstpa; 210 ste = &ste[SG4_LEV1SIZE - 1]; 211 *ste = protoste; 212 /* 213 * Now initialize the final portion of that block of 214 * descriptors to map Sysmap and the "last PT page". 215 */ 216 i = SG4_LEV1SIZE + (nl1desc * SG4_LEV2SIZE); 217 ste = (st_entry_t *)kstpa; 218 ste = &ste[i + SG4_LEV2SIZE - (NPTEPG / SG4_LEV3SIZE) * 2]; 219 este = &ste[NPTEPG / SG4_LEV3SIZE]; 220 protoste = kptmpa | SG_U | SG_RW | SG_V; 221 while (ste < este) { 222 *ste++ = protoste; 223 protoste += (SG4_LEV3SIZE * sizeof(st_entry_t)); 224 } 225 este = &ste[NPTEPG / SG4_LEV3SIZE]; 226 protoste = lkptpa | SG_U | SG_RW | SG_V; 227 while (ste < este) { 228 *ste++ = protoste; 229 protoste += (SG4_LEV3SIZE * sizeof(st_entry_t)); 230 } 231 /* 232 * Calculate the free level 2 descriptor mask 233 * noting that we have used: 234 * 0: level 1 table 235 * 1 to nl1desc: map page tables 236 * nl1desc + 1: maps kptmpa and last-page page table 237 */ 238 /* mark an entry for level 1 table */ 239 stfree = ~l2tobm(0); 240 /* mark entries for map page tables */ 241 for (i = 1; i <= nl1desc; i++) 242 stfree &= ~l2tobm(i); 243 /* mark an entry for kptmpa and lkptpa */ 244 stfree &= ~l2tobm(i); 245 /* mark entries not available */ 246 for (i = MAXKL2SIZE; i < sizeof(stfree) * NBBY; i++) 247 stfree &= ~l2tobm(i); 248 249 /* 250 * Initialize Sysptmap 251 */ 252 pte = (pt_entry_t *)kptmpa; 253 epte = &pte[nptpages]; 254 protopte = kptpa | PG_RW | PG_CI | PG_V; 255 while (pte < epte) { 256 *pte++ = protopte; 257 protopte += PAGE_SIZE; 258 } 259 /* 260 * Invalidate all remaining entries. 261 */ 262 epte = (pt_entry_t *)kptmpa; 263 epte = &epte[TIB_SIZE]; 264 while (pte < epte) { 265 *pte++ = PG_NV; 266 } 267 /* 268 * Initialize the last ones to point to Sysptmap and the page 269 * table page allocated earlier. 270 */ 271 pte = (pt_entry_t *)kptmpa; 272 pte = &pte[SYSMAP_VA >> SEGSHIFT]; 273 *pte = kptmpa | PG_RW | PG_CI | PG_V; 274 pte++; /* XXX should use [MAXADDR >> SEGSHIFT] */ 275 *pte = lkptpa | PG_RW | PG_CI | PG_V; 276 } else { 277 /* 278 * Map the page table pages in both the HW segment table 279 * and the software Sysptmap. 280 */ 281 ste = (st_entry_t *)kstpa; 282 pte = (pt_entry_t *)kptmpa; 283 epte = &pte[nptpages]; 284 protoste = kptpa | SG_RW | SG_V; 285 protopte = kptpa | PG_RW | PG_CI | PG_V; 286 while (pte < epte) { 287 *ste++ = protoste; 288 *pte++ = protopte; 289 protoste += PAGE_SIZE; 290 protopte += PAGE_SIZE; 291 } 292 /* 293 * Invalidate all remaining entries in both. 294 */ 295 este = (st_entry_t *)kstpa; 296 este = &este[TIA_SIZE]; 297 while (ste < este) 298 *ste++ = SG_NV; 299 epte = (pt_entry_t *)kptmpa; 300 epte = &epte[TIB_SIZE]; 301 while (pte < epte) 302 *pte++ = PG_NV; 303 /* 304 * Initialize the last ones to point to Sysptmap and the page 305 * table page allocated earlier. 306 */ 307 ste = (st_entry_t *)kstpa; 308 ste = &ste[SYSMAP_VA >> SEGSHIFT]; 309 pte = (pt_entry_t *)kptmpa; 310 pte = &pte[SYSMAP_VA >> SEGSHIFT]; 311 *ste = kptmpa | SG_RW | SG_V; 312 *pte = kptmpa | PG_RW | PG_CI | PG_V; 313 ste++; /* XXX should use [MAXADDR >> SEGSHIFT] */ 314 pte++; /* XXX should use [MAXADDR >> SEGSHIFT] */ 315 *ste = lkptpa | SG_RW | SG_V; 316 *pte = lkptpa | PG_RW | PG_CI | PG_V; 317 } 318 319 /* 320 * Invalidate all but the final entry in the last kernel PT page. 321 * The final entry maps the last page of physical memory to 322 * prepare a page that is PA == VA to turn on the MMU. 323 * 324 * XXX: This looks copied from hp300 where PA != VA, but 325 * XXX: it's suspicious if this is also required on this port. 326 */ 327 pte = (pt_entry_t *)lkptpa; 328 epte = &pte[NPTEPG]; 329 while (pte < epte) 330 *pte++ = PG_NV; 331 /* 332 * Initialize kernel page table. 333 * Start by invalidating the `nptpages' that we have allocated. 334 */ 335 pte = (pt_entry_t *)kptpa; 336 epte = &pte[nptpages * NPTEPG]; 337 while (pte < epte) 338 *pte++ = PG_NV; 339 /* 340 * Validate PTEs for kernel text (RO). 341 */ 342 pte = (pt_entry_t *)kptpa; 343 pte = &pte[m68k_btop(KERNBASE)]; 344 epte = &((u_int *)kptpa)[m68k_btop(m68k_trunc_page(&etext))]; 345 protopte = firstpa | PG_RO | PG_V; 346 while (pte < epte) { 347 *pte++ = protopte; 348 protopte += PAGE_SIZE; 349 } 350 /* 351 * Validate PTEs for kernel data/bss, dynamic data allocated 352 * by us so far (kstpa - firstpa bytes), and pages for lwp0 353 * u-area and page table allocated below (RW). 354 */ 355 epte = (pt_entry_t *)kptpa; 356 epte = &epte[m68k_btop(KERNBASE + kstpa - firstpa)]; 357 protopte = (protopte & ~PG_PROT) | PG_RW; 358 /* 359 * Enable copy-back caching of data pages 360 */ 361 if (RELOC(mmutype, int) == MMU_68040) 362 protopte |= PG_CCB; 363 while (pte < epte) { 364 *pte++ = protopte; 365 protopte += PAGE_SIZE; 366 } 367 /* 368 * Map the kernel segment table cache invalidated for 68040/68060. 369 * (for the 68040 not strictly necessary, but recommended by Motorola; 370 * for the 68060 mandatory) 371 */ 372 epte = (pt_entry_t *)kptpa; 373 epte = &epte[m68k_btop(KERNBASE + nextpa - firstpa)]; 374 protopte = (protopte & ~PG_PROT) | PG_RW; 375 if (RELOC(mmutype, int) == MMU_68040) { 376 protopte &= ~PG_CCB; 377 protopte |= PG_CIN; 378 } 379 while (pte < epte) { 380 *pte++ = protopte; 381 protopte += PAGE_SIZE; 382 } 383 384 /* 385 * Calculate important exported kernel addresses and related values. 386 */ 387 /* 388 * Sysseg: base of kernel segment table 389 */ 390 RELOC(Sysseg, st_entry_t *) = 391 (st_entry_t *)(kstpa - firstpa + KERNBASE); 392 RELOC(Sysseg_pa, paddr_t) = kstpa; 393 if (RELOC(mmutype, int) == MMU_68040) 394 RELOC(protostfree, u_int) = stfree; 395 /* 396 * Sysptmap: base of kernel page table map 397 */ 398 RELOC(Sysptmap, pt_entry_t *) = 399 (pt_entry_t *)(kptmpa - firstpa + KERNBASE); 400 /* 401 * Sysmap: kernel page table (as mapped through Sysptmap) 402 * Allocated at the end of KVA space. 403 */ 404 RELOC(Sysmap, pt_entry_t *) = (pt_entry_t *)SYSMAP_VA; 405 406 /* 407 * Remember the u-area address so it can be loaded in the lwp0 408 * via uvm_lwp_setuarea() later in pmap_bootstrap2(). 409 */ 410 RELOC(lwp0uarea, vaddr_t) = lwp0upa - firstpa + KERNBASE; 411 412 /* 413 * VM data structures are now initialized, set up data for 414 * the pmap module. 415 * 416 * Note about avail_end: msgbuf is initialized just after 417 * avail_end in machdep.c. 418 * Since the last page is used for rebooting the system 419 * (code is copied there and execution continues from copied code 420 * before the MMU is disabled), the msgbuf will get trounced 421 * between reboots if it's placed in the last physical page. 422 * To work around this, we move avail_end back one more 423 * page so the msgbuf can be preserved. 424 */ 425 RELOC(virtual_avail, vaddr_t) = 426 KERNBASE + (nextpa - firstpa); 427 RELOC(virtual_end, vaddr_t) = VM_MAX_KERNEL_ADDRESS; 428 429 /* 430 * Allocate some fixed, special purpose kernel virtual addresses 431 */ 432 { 433 vaddr_t va = RELOC(virtual_avail, vaddr_t); 434 435 RELOC(CADDR1, void *) = (void *)va; 436 va += PAGE_SIZE; 437 RELOC(CADDR2, void *) = (void *)va; 438 va += PAGE_SIZE; 439 RELOC(vmmap, void *) = (void *)va; 440 va += PAGE_SIZE; 441 RELOC(msgbufaddr, void *) = (void *)va; 442 va += m68k_round_page(MSGBUFSIZE); 443 RELOC(virtual_avail, vaddr_t) = va; 444 } 445 446 return nextpa; 447 } 448
Indexes created Sun Oct 25 00:26:45 UTC 2026