1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * This file contains the routines for TLB flushing. 4 * On machines where the MMU does not use a hash table to store virtual to 5 * physical translations (ie, SW loaded TLBs or Book3E compilant processors, 6 * this does -not- include 603 however which shares the implementation with 7 * hash based processors) 8 * 9 * -- BenH 10 * 11 * Copyright 2008,2009 Ben Herrenschmidt <benh@kernel.crashing.org> 12 * IBM Corp. 13 * 14 * Derived from arch/ppc/mm/init.c: 15 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org) 16 * 17 * Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au) 18 * and Cort Dougan (PReP) (cort@cs.nmt.edu) 19 * Copyright (C) 1996 Paul Mackerras 20 * 21 * Derived from "arch/i386/mm/init.c" 22 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds 23 */ 24 25 #include <linux/kernel.h> 26 #include <linux/export.h> 27 #include <linux/mm.h> 28 #include <linux/init.h> 29 #include <linux/highmem.h> 30 #include <linux/pagemap.h> 31 #include <linux/preempt.h> 32 #include <linux/spinlock.h> 33 #include <linux/memblock.h> 34 #include <linux/of_fdt.h> 35 #include <linux/hugetlb.h> 36 37 #include <asm/pgalloc.h> 38 #include <asm/tlbflush.h> 39 #include <asm/tlb.h> 40 #include <asm/code-patching.h> 41 #include <asm/cputhreads.h> 42 #include <asm/hugetlb.h> 43 #include <asm/paca.h> 44 45 #include <mm/mmu_decl.h> 46 47 /* 48 * This struct lists the sw-supported page sizes. The hardawre MMU may support 49 * other sizes not listed here. The .ind field is only used on MMUs that have 50 * indirect page table entries. 51 */ 52 #ifdef CONFIG_PPC_E500 53 struct mmu_psize_def mmu_psize_defs[MMU_PAGE_COUNT] = { 54 [MMU_PAGE_4K] = { 55 .shift = 12, 56 .enc = BOOK3E_PAGESZ_4K, 57 }, 58 [MMU_PAGE_2M] = { 59 .shift = 21, 60 .enc = BOOK3E_PAGESZ_2M, 61 }, 62 [MMU_PAGE_4M] = { 63 .shift = 22, 64 .enc = BOOK3E_PAGESZ_4M, 65 }, 66 [MMU_PAGE_16M] = { 67 .shift = 24, 68 .enc = BOOK3E_PAGESZ_16M, 69 }, 70 [MMU_PAGE_64M] = { 71 .shift = 26, 72 .enc = BOOK3E_PAGESZ_64M, 73 }, 74 [MMU_PAGE_256M] = { 75 .shift = 28, 76 .enc = BOOK3E_PAGESZ_256M, 77 }, 78 [MMU_PAGE_1G] = { 79 .shift = 30, 80 .enc = BOOK3E_PAGESZ_1GB, 81 }, 82 }; 83 84 static inline int mmu_get_tsize(int psize) 85 { 86 return mmu_psize_defs[psize].enc; 87 } 88 #else 89 static inline int mmu_get_tsize(int psize) 90 { 91 /* This isn't used on !Book3E for now */ 92 return 0; 93 } 94 #endif 95 96 #ifdef CONFIG_PPC_8xx 97 struct mmu_psize_def mmu_psize_defs[MMU_PAGE_COUNT] = { 98 [MMU_PAGE_4K] = { 99 .shift = 12, 100 }, 101 [MMU_PAGE_16K] = { 102 .shift = 14, 103 }, 104 [MMU_PAGE_512K] = { 105 .shift = 19, 106 }, 107 [MMU_PAGE_8M] = { 108 .shift = 23, 109 }, 110 }; 111 #endif 112 113 /* The variables below are currently only used on 64-bit Book3E 114 * though this will probably be made common with other nohash 115 * implementations at some point 116 */ 117 #ifdef CONFIG_PPC64 118 119 int mmu_pte_psize; /* Page size used for PTE pages */ 120 int mmu_vmemmap_psize; /* Page size used for the virtual mem map */ 121 int book3e_htw_mode; /* HW tablewalk? Value is PPC_HTW_* */ 122 unsigned long linear_map_top; /* Top of linear mapping */ 123 124 125 /* 126 * Number of bytes to add to SPRN_SPRG_TLB_EXFRAME on crit/mcheck/debug 127 * exceptions. This is used for bolted and e6500 TLB miss handlers which 128 * do not modify this SPRG in the TLB miss code; for other TLB miss handlers, 129 * this is set to zero. 130 */ 131 int extlb_level_exc; 132 133 #endif /* CONFIG_PPC64 */ 134 135 #ifdef CONFIG_PPC_E500 136 /* next_tlbcam_idx is used to round-robin tlbcam entry assignment */ 137 DEFINE_PER_CPU(int, next_tlbcam_idx); 138 EXPORT_PER_CPU_SYMBOL(next_tlbcam_idx); 139 #endif 140 141 /* 142 * Base TLB flushing operations: 143 * 144 * - flush_tlb_mm(mm) flushes the specified mm context TLB's 145 * - flush_tlb_page(vma, vmaddr) flushes one page 146 * - flush_tlb_range(vma, start, end) flushes a range of pages 147 * - flush_tlb_kernel_range(start, end) flushes kernel pages 148 * 149 * - local_* variants of page and mm only apply to the current 150 * processor 151 */ 152 153 #ifndef CONFIG_PPC_8xx 154 /* 155 * These are the base non-SMP variants of page and mm flushing 156 */ 157 void local_flush_tlb_mm(struct mm_struct *mm) 158 { 159 unsigned int pid; 160 161 preempt_disable(); 162 pid = mm->context.id; 163 if (pid != MMU_NO_CONTEXT) 164 _tlbil_pid(pid); 165 preempt_enable(); 166 } 167 EXPORT_SYMBOL(local_flush_tlb_mm); 168 169 void __local_flush_tlb_page(struct mm_struct *mm, unsigned long vmaddr, 170 int tsize, int ind) 171 { 172 unsigned int pid; 173 174 preempt_disable(); 175 pid = mm ? mm->context.id : 0; 176 if (pid != MMU_NO_CONTEXT) 177 _tlbil_va(vmaddr, pid, tsize, ind); 178 preempt_enable(); 179 } 180 181 void local_flush_tlb_page(struct vm_area_struct *vma, unsigned long vmaddr) 182 { 183 __local_flush_tlb_page(vma ? vma->vm_mm : NULL, vmaddr, 184 mmu_get_tsize(mmu_virtual_psize), 0); 185 } 186 EXPORT_SYMBOL(local_flush_tlb_page); 187 #endif 188 189 /* 190 * And here are the SMP non-local implementations 191 */ 192 #ifdef CONFIG_SMP 193 194 static DEFINE_RAW_SPINLOCK(tlbivax_lock); 195 196 struct tlb_flush_param { 197 unsigned long addr; 198 unsigned int pid; 199 unsigned int tsize; 200 unsigned int ind; 201 }; 202 203 static void do_flush_tlb_mm_ipi(void *param) 204 { 205 struct tlb_flush_param *p = param; 206 207 _tlbil_pid(p ? p->pid : 0); 208 } 209 210 static void do_flush_tlb_page_ipi(void *param) 211 { 212 struct tlb_flush_param *p = param; 213 214 _tlbil_va(p->addr, p->pid, p->tsize, p->ind); 215 } 216 217 218 /* Note on invalidations and PID: 219 * 220 * We snapshot the PID with preempt disabled. At this point, it can still 221 * change either because: 222 * - our context is being stolen (PID -> NO_CONTEXT) on another CPU 223 * - we are invaliating some target that isn't currently running here 224 * and is concurrently acquiring a new PID on another CPU 225 * - some other CPU is re-acquiring a lost PID for this mm 226 * etc... 227 * 228 * However, this shouldn't be a problem as we only guarantee 229 * invalidation of TLB entries present prior to this call, so we 230 * don't care about the PID changing, and invalidating a stale PID 231 * is generally harmless. 232 */ 233 234 void flush_tlb_mm(struct mm_struct *mm) 235 { 236 unsigned int pid; 237 238 preempt_disable(); 239 pid = mm->context.id; 240 if (unlikely(pid == MMU_NO_CONTEXT)) 241 goto no_context; 242 if (!mm_is_core_local(mm)) { 243 struct tlb_flush_param p = { .pid = pid }; 244 /* Ignores smp_processor_id() even if set. */ 245 smp_call_function_many(mm_cpumask(mm), 246 do_flush_tlb_mm_ipi, &p, 1); 247 } 248 _tlbil_pid(pid); 249 no_context: 250 preempt_enable(); 251 } 252 EXPORT_SYMBOL(flush_tlb_mm); 253 254 void __flush_tlb_page(struct mm_struct *mm, unsigned long vmaddr, 255 int tsize, int ind) 256 { 257 struct cpumask *cpu_mask; 258 unsigned int pid; 259 260 /* 261 * This function as well as __local_flush_tlb_page() must only be called 262 * for user contexts. 263 */ 264 if (WARN_ON(!mm)) 265 return; 266 267 preempt_disable(); 268 pid = mm->context.id; 269 if (unlikely(pid == MMU_NO_CONTEXT)) 270 goto bail; 271 cpu_mask = mm_cpumask(mm); 272 if (!mm_is_core_local(mm)) { 273 /* If broadcast tlbivax is supported, use it */ 274 if (mmu_has_feature(MMU_FTR_USE_TLBIVAX_BCAST)) { 275 int lock = mmu_has_feature(MMU_FTR_LOCK_BCAST_INVAL); 276 if (lock) 277 raw_spin_lock(&tlbivax_lock); 278 _tlbivax_bcast(vmaddr, pid, tsize, ind); 279 if (lock) 280 raw_spin_unlock(&tlbivax_lock); 281 goto bail; 282 } else { 283 struct tlb_flush_param p = { 284 .pid = pid, 285 .addr = vmaddr, 286 .tsize = tsize, 287 .ind = ind, 288 }; 289 /* Ignores smp_processor_id() even if set in cpu_mask */ 290 smp_call_function_many(cpu_mask, 291 do_flush_tlb_page_ipi, &p, 1); 292 } 293 } 294 _tlbil_va(vmaddr, pid, tsize, ind); 295 bail: 296 preempt_enable(); 297 } 298 299 void flush_tlb_page(struct vm_area_struct *vma, unsigned long vmaddr) 300 { 301 #ifdef CONFIG_HUGETLB_PAGE 302 if (vma && is_vm_hugetlb_page(vma)) 303 flush_hugetlb_page(vma, vmaddr); 304 #endif 305 306 __flush_tlb_page(vma ? vma->vm_mm : NULL, vmaddr, 307 mmu_get_tsize(mmu_virtual_psize), 0); 308 } 309 EXPORT_SYMBOL(flush_tlb_page); 310 311 #endif /* CONFIG_SMP */ 312 313 #ifdef CONFIG_PPC_47x 314 void __init early_init_mmu_47x(void) 315 { 316 #ifdef CONFIG_SMP 317 unsigned long root = of_get_flat_dt_root(); 318 if (of_get_flat_dt_prop(root, "cooperative-partition", NULL)) 319 mmu_clear_feature(MMU_FTR_USE_TLBIVAX_BCAST); 320 #endif /* CONFIG_SMP */ 321 } 322 #endif /* CONFIG_PPC_47x */ 323 324 /* 325 * Flush kernel TLB entries in the given range 326 */ 327 #ifndef CONFIG_PPC_8xx 328 void flush_tlb_kernel_range(unsigned long start, unsigned long end) 329 { 330 #ifdef CONFIG_SMP 331 preempt_disable(); 332 smp_call_function(do_flush_tlb_mm_ipi, NULL, 1); 333 _tlbil_pid(0); 334 preempt_enable(); 335 #else 336 _tlbil_pid(0); 337 #endif 338 } 339 EXPORT_SYMBOL(flush_tlb_kernel_range); 340 #endif 341 342 /* 343 * Currently, for range flushing, we just do a full mm flush. This should 344 * be optimized based on a threshold on the size of the range, since 345 * some implementation can stack multiple tlbivax before a tlbsync but 346 * for now, we keep it that way 347 */ 348 void flush_tlb_range(struct vm_area_struct *vma, unsigned long start, 349 unsigned long end) 350 351 { 352 if (end - start == PAGE_SIZE && !(start & ~PAGE_MASK)) 353 flush_tlb_page(vma, start); 354 else 355 flush_tlb_mm(vma->vm_mm); 356 } 357 EXPORT_SYMBOL(flush_tlb_range); 358 359 void tlb_flush(struct mmu_gather *tlb) 360 { 361 flush_tlb_mm(tlb->mm); 362 } 363 364 /* 365 * Below are functions specific to the 64-bit variant of Book3E though that 366 * may change in the future 367 */ 368 369 #ifdef CONFIG_PPC64 370 371 /* 372 * Handling of virtual linear page tables or indirect TLB entries 373 * flushing when PTE pages are freed 374 */ 375 void tlb_flush_pgtable(struct mmu_gather *tlb, unsigned long address) 376 { 377 int tsize = mmu_psize_defs[mmu_pte_psize].enc; 378 379 if (book3e_htw_mode != PPC_HTW_NONE) { 380 unsigned long start = address & PMD_MASK; 381 unsigned long end = address + PMD_SIZE; 382 unsigned long size = 1UL << mmu_psize_defs[mmu_pte_psize].shift; 383 384 /* This isn't the most optimal, ideally we would factor out the 385 * while preempt & CPU mask mucking around, or even the IPI but 386 * it will do for now 387 */ 388 while (start < end) { 389 __flush_tlb_page(tlb->mm, start, tsize, 1); 390 start += size; 391 } 392 } else { 393 unsigned long rmask = 0xf000000000000000ul; 394 unsigned long rid = (address & rmask) | 0x1000000000000000ul; 395 unsigned long vpte = address & ~rmask; 396 397 vpte = (vpte >> (PAGE_SHIFT - 3)) & ~0xffful; 398 vpte |= rid; 399 __flush_tlb_page(tlb->mm, vpte, tsize, 0); 400 } 401 } 402 403 static void __init setup_page_sizes(void) 404 { 405 unsigned int tlb0cfg; 406 unsigned int tlb0ps; 407 unsigned int eptcfg; 408 int i, psize; 409 410 #ifdef CONFIG_PPC_E500 411 unsigned int mmucfg = mfspr(SPRN_MMUCFG); 412 int fsl_mmu = mmu_has_feature(MMU_FTR_TYPE_FSL_E); 413 414 if (fsl_mmu && (mmucfg & MMUCFG_MAVN) == MMUCFG_MAVN_V1) { 415 unsigned int tlb1cfg = mfspr(SPRN_TLB1CFG); 416 unsigned int min_pg, max_pg; 417 418 min_pg = (tlb1cfg & TLBnCFG_MINSIZE) >> TLBnCFG_MINSIZE_SHIFT; 419 max_pg = (tlb1cfg & TLBnCFG_MAXSIZE) >> TLBnCFG_MAXSIZE_SHIFT; 420 421 for (psize = 0; psize < MMU_PAGE_COUNT; ++psize) { 422 struct mmu_psize_def *def; 423 unsigned int shift; 424 425 def = &mmu_psize_defs[psize]; 426 shift = def->shift; 427 428 if (shift == 0 || shift & 1) 429 continue; 430 431 /* adjust to be in terms of 4^shift Kb */ 432 shift = (shift - 10) >> 1; 433 434 if ((shift >= min_pg) && (shift <= max_pg)) 435 def->flags |= MMU_PAGE_SIZE_DIRECT; 436 } 437 438 goto out; 439 } 440 441 if (fsl_mmu && (mmucfg & MMUCFG_MAVN) == MMUCFG_MAVN_V2) { 442 u32 tlb1cfg, tlb1ps; 443 444 tlb0cfg = mfspr(SPRN_TLB0CFG); 445 tlb1cfg = mfspr(SPRN_TLB1CFG); 446 tlb1ps = mfspr(SPRN_TLB1PS); 447 eptcfg = mfspr(SPRN_EPTCFG); 448 449 if ((tlb1cfg & TLBnCFG_IND) && (tlb0cfg & TLBnCFG_PT)) 450 book3e_htw_mode = PPC_HTW_E6500; 451 452 /* 453 * We expect 4K subpage size and unrestricted indirect size. 454 * The lack of a restriction on indirect size is a Freescale 455 * extension, indicated by PSn = 0 but SPSn != 0. 456 */ 457 if (eptcfg != 2) 458 book3e_htw_mode = PPC_HTW_NONE; 459 460 for (psize = 0; psize < MMU_PAGE_COUNT; ++psize) { 461 struct mmu_psize_def *def = &mmu_psize_defs[psize]; 462 463 if (!def->shift) 464 continue; 465 466 if (tlb1ps & (1U << (def->shift - 10))) { 467 def->flags |= MMU_PAGE_SIZE_DIRECT; 468 469 if (book3e_htw_mode && psize == MMU_PAGE_2M) 470 def->flags |= MMU_PAGE_SIZE_INDIRECT; 471 } 472 } 473 474 goto out; 475 } 476 #endif 477 478 tlb0cfg = mfspr(SPRN_TLB0CFG); 479 tlb0ps = mfspr(SPRN_TLB0PS); 480 eptcfg = mfspr(SPRN_EPTCFG); 481 482 /* Look for supported direct sizes */ 483 for (psize = 0; psize < MMU_PAGE_COUNT; ++psize) { 484 struct mmu_psize_def *def = &mmu_psize_defs[psize]; 485 486 if (tlb0ps & (1U << (def->shift - 10))) 487 def->flags |= MMU_PAGE_SIZE_DIRECT; 488 } 489 490 /* Indirect page sizes supported ? */ 491 if ((tlb0cfg & TLBnCFG_IND) == 0 || 492 (tlb0cfg & TLBnCFG_PT) == 0) 493 goto out; 494 495 book3e_htw_mode = PPC_HTW_IBM; 496 497 /* Now, we only deal with one IND page size for each 498 * direct size. Hopefully all implementations today are 499 * unambiguous, but we might want to be careful in the 500 * future. 501 */ 502 for (i = 0; i < 3; i++) { 503 unsigned int ps, sps; 504 505 sps = eptcfg & 0x1f; 506 eptcfg >>= 5; 507 ps = eptcfg & 0x1f; 508 eptcfg >>= 5; 509 if (!ps || !sps) 510 continue; 511 for (psize = 0; psize < MMU_PAGE_COUNT; psize++) { 512 struct mmu_psize_def *def = &mmu_psize_defs[psize]; 513 514 if (ps == (def->shift - 10)) 515 def->flags |= MMU_PAGE_SIZE_INDIRECT; 516 if (sps == (def->shift - 10)) 517 def->ind = ps + 10; 518 } 519 } 520 521 out: 522 /* Cleanup array and print summary */ 523 pr_info("MMU: Supported page sizes\n"); 524 for (psize = 0; psize < MMU_PAGE_COUNT; ++psize) { 525 struct mmu_psize_def *def = &mmu_psize_defs[psize]; 526 const char *__page_type_names[] = { 527 "unsupported", 528 "direct", 529 "indirect", 530 "direct & indirect" 531 }; 532 if (def->flags == 0) { 533 def->shift = 0; 534 continue; 535 } 536 pr_info(" %8ld KB as %s\n", 1ul << (def->shift - 10), 537 __page_type_names[def->flags & 0x3]); 538 } 539 } 540 541 static void __init setup_mmu_htw(void) 542 { 543 /* 544 * If we want to use HW tablewalk, enable it by patching the TLB miss 545 * handlers to branch to the one dedicated to it. 546 */ 547 548 switch (book3e_htw_mode) { 549 case PPC_HTW_IBM: 550 patch_exception(0x1c0, exc_data_tlb_miss_htw_book3e); 551 patch_exception(0x1e0, exc_instruction_tlb_miss_htw_book3e); 552 break; 553 #ifdef CONFIG_PPC_E500 554 case PPC_HTW_E6500: 555 extlb_level_exc = EX_TLB_SIZE; 556 patch_exception(0x1c0, exc_data_tlb_miss_e6500_book3e); 557 patch_exception(0x1e0, exc_instruction_tlb_miss_e6500_book3e); 558 break; 559 #endif 560 } 561 pr_info("MMU: Book3E HW tablewalk %s\n", 562 book3e_htw_mode != PPC_HTW_NONE ? "enabled" : "not supported"); 563 } 564 565 /* 566 * Early initialization of the MMU TLB code 567 */ 568 static void early_init_this_mmu(void) 569 { 570 unsigned int mas4; 571 572 /* Set MAS4 based on page table setting */ 573 574 mas4 = 0x4 << MAS4_WIMGED_SHIFT; 575 switch (book3e_htw_mode) { 576 case PPC_HTW_E6500: 577 mas4 |= MAS4_INDD; 578 mas4 |= BOOK3E_PAGESZ_2M << MAS4_TSIZED_SHIFT; 579 mas4 |= MAS4_TLBSELD(1); 580 mmu_pte_psize = MMU_PAGE_2M; 581 break; 582 583 case PPC_HTW_IBM: 584 mas4 |= MAS4_INDD; 585 mas4 |= BOOK3E_PAGESZ_1M << MAS4_TSIZED_SHIFT; 586 mmu_pte_psize = MMU_PAGE_1M; 587 break; 588 589 case PPC_HTW_NONE: 590 mas4 |= BOOK3E_PAGESZ_4K << MAS4_TSIZED_SHIFT; 591 mmu_pte_psize = mmu_virtual_psize; 592 break; 593 } 594 mtspr(SPRN_MAS4, mas4); 595 596 #ifdef CONFIG_PPC_E500 597 if (mmu_has_feature(MMU_FTR_TYPE_FSL_E)) { 598 unsigned int num_cams; 599 bool map = true; 600 601 /* use a quarter of the TLBCAM for bolted linear map */ 602 num_cams = (mfspr(SPRN_TLB1CFG) & TLBnCFG_N_ENTRY) / 4; 603 604 /* 605 * Only do the mapping once per core, or else the 606 * transient mapping would cause problems. 607 */ 608 #ifdef CONFIG_SMP 609 if (hweight32(get_tensr()) > 1) 610 map = false; 611 #endif 612 613 if (map) 614 linear_map_top = map_mem_in_cams(linear_map_top, 615 num_cams, false, true); 616 } 617 #endif 618 619 /* A sync won't hurt us after mucking around with 620 * the MMU configuration 621 */ 622 mb(); 623 } 624 625 static void __init early_init_mmu_global(void) 626 { 627 /* XXX This should be decided at runtime based on supported 628 * page sizes in the TLB, but for now let's assume 16M is 629 * always there and a good fit (which it probably is) 630 * 631 * Freescale booke only supports 4K pages in TLB0, so use that. 632 */ 633 if (mmu_has_feature(MMU_FTR_TYPE_FSL_E)) 634 mmu_vmemmap_psize = MMU_PAGE_4K; 635 else 636 mmu_vmemmap_psize = MMU_PAGE_16M; 637 638 /* XXX This code only checks for TLB 0 capabilities and doesn't 639 * check what page size combos are supported by the HW. It 640 * also doesn't handle the case where a separate array holds 641 * the IND entries from the array loaded by the PT. 642 */ 643 /* Look for supported page sizes */ 644 setup_page_sizes(); 645 646 /* Look for HW tablewalk support */ 647 setup_mmu_htw(); 648 649 #ifdef CONFIG_PPC_E500 650 if (mmu_has_feature(MMU_FTR_TYPE_FSL_E)) { 651 if (book3e_htw_mode == PPC_HTW_NONE) { 652 extlb_level_exc = EX_TLB_SIZE; 653 patch_exception(0x1c0, exc_data_tlb_miss_bolted_book3e); 654 patch_exception(0x1e0, 655 exc_instruction_tlb_miss_bolted_book3e); 656 } 657 } 658 #endif 659 660 /* Set the global containing the top of the linear mapping 661 * for use by the TLB miss code 662 */ 663 linear_map_top = memblock_end_of_DRAM(); 664 665 ioremap_bot = IOREMAP_BASE; 666 } 667 668 static void __init early_mmu_set_memory_limit(void) 669 { 670 #ifdef CONFIG_PPC_E500 671 if (mmu_has_feature(MMU_FTR_TYPE_FSL_E)) { 672 /* 673 * Limit memory so we dont have linear faults. 674 * Unlike memblock_set_current_limit, which limits 675 * memory available during early boot, this permanently 676 * reduces the memory available to Linux. We need to 677 * do this because highmem is not supported on 64-bit. 678 */ 679 memblock_enforce_memory_limit(linear_map_top); 680 } 681 #endif 682 683 memblock_set_current_limit(linear_map_top); 684 } 685 686 /* boot cpu only */ 687 void __init early_init_mmu(void) 688 { 689 early_init_mmu_global(); 690 early_init_this_mmu(); 691 early_mmu_set_memory_limit(); 692 } 693 694 void early_init_mmu_secondary(void) 695 { 696 early_init_this_mmu(); 697 } 698 699 void setup_initial_memory_limit(phys_addr_t first_memblock_base, 700 phys_addr_t first_memblock_size) 701 { 702 /* On non-FSL Embedded 64-bit, we adjust the RMA size to match 703 * the bolted TLB entry. We know for now that only 1G 704 * entries are supported though that may eventually 705 * change. 706 * 707 * on FSL Embedded 64-bit, usually all RAM is bolted, but with 708 * unusual memory sizes it's possible for some RAM to not be mapped 709 * (such RAM is not used at all by Linux, since we don't support 710 * highmem on 64-bit). We limit ppc64_rma_size to what would be 711 * mappable if this memblock is the only one. Additional memblocks 712 * can only increase, not decrease, the amount that ends up getting 713 * mapped. We still limit max to 1G even if we'll eventually map 714 * more. This is due to what the early init code is set up to do. 715 * 716 * We crop it to the size of the first MEMBLOCK to 717 * avoid going over total available memory just in case... 718 */ 719 #ifdef CONFIG_PPC_E500 720 if (early_mmu_has_feature(MMU_FTR_TYPE_FSL_E)) { 721 unsigned long linear_sz; 722 unsigned int num_cams; 723 724 /* use a quarter of the TLBCAM for bolted linear map */ 725 num_cams = (mfspr(SPRN_TLB1CFG) & TLBnCFG_N_ENTRY) / 4; 726 727 linear_sz = map_mem_in_cams(first_memblock_size, num_cams, 728 true, true); 729 730 ppc64_rma_size = min_t(u64, linear_sz, 0x40000000); 731 } else 732 #endif 733 ppc64_rma_size = min_t(u64, first_memblock_size, 0x40000000); 734 735 /* Finally limit subsequent allocations */ 736 memblock_set_current_limit(first_memblock_base + ppc64_rma_size); 737 } 738 #else /* ! CONFIG_PPC64 */ 739 void __init early_init_mmu(void) 740 { 741 #ifdef CONFIG_PPC_47x 742 early_init_mmu_47x(); 743 #endif 744 } 745 #endif /* CONFIG_PPC64 */ 746