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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 | // SPDX-License-Identifier: GPL-2.0-or-later /* * This file contains the routines for TLB flushing. * On machines where the MMU does not use a hash table to store virtual to * physical translations (ie, SW loaded TLBs or Book3E compilant processors, * this does -not- include 603 however which shares the implementation with * hash based processors) * * -- BenH * * Copyright 2008,2009 Ben Herrenschmidt <benh@kernel.crashing.org> * IBM Corp. * * Derived from arch/ppc/mm/init.c: * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org) * * Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au) * and Cort Dougan (PReP) (cort@cs.nmt.edu) * Copyright (C) 1996 Paul Mackerras * * Derived from "arch/i386/mm/init.c" * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds */ #include <linux/kernel.h> #include <linux/export.h> #include <linux/mm.h> #include <linux/init.h> #include <linux/highmem.h> #include <linux/pagemap.h> #include <linux/preempt.h> #include <linux/spinlock.h> #include <linux/memblock.h> #include <linux/of_fdt.h> #include <linux/hugetlb.h> #include <asm/pgalloc.h> #include <asm/tlbflush.h> #include <asm/tlb.h> #include <asm/code-patching.h> #include <asm/cputhreads.h> #include <asm/hugetlb.h> #include <asm/paca.h> #include <mm/mmu_decl.h> /* * This struct lists the sw-supported page sizes. The hardawre MMU may support * other sizes not listed here. The .ind field is only used on MMUs that have * indirect page table entries. */ #ifdef CONFIG_PPC_E500 struct mmu_psize_def mmu_psize_defs[MMU_PAGE_COUNT] = { [MMU_PAGE_4K] = { .shift = 12, .enc = BOOK3E_PAGESZ_4K, }, [MMU_PAGE_2M] = { .shift = 21, .enc = BOOK3E_PAGESZ_2M, }, [MMU_PAGE_4M] = { .shift = 22, .enc = BOOK3E_PAGESZ_4M, }, [MMU_PAGE_16M] = { .shift = 24, .enc = BOOK3E_PAGESZ_16M, }, [MMU_PAGE_64M] = { .shift = 26, .enc = BOOK3E_PAGESZ_64M, }, [MMU_PAGE_256M] = { .shift = 28, .enc = BOOK3E_PAGESZ_256M, }, [MMU_PAGE_1G] = { .shift = 30, .enc = BOOK3E_PAGESZ_1GB, }, }; static inline int mmu_get_tsize(int psize) { return mmu_psize_defs[psize].enc; } #else static inline int mmu_get_tsize(int psize) { /* This isn't used on !Book3E for now */ return 0; } #endif #ifdef CONFIG_PPC_8xx struct mmu_psize_def mmu_psize_defs[MMU_PAGE_COUNT] = { [MMU_PAGE_4K] = { .shift = 12, }, [MMU_PAGE_16K] = { .shift = 14, }, [MMU_PAGE_512K] = { .shift = 19, }, [MMU_PAGE_8M] = { .shift = 23, }, }; #endif /* The variables below are currently only used on 64-bit Book3E * though this will probably be made common with other nohash * implementations at some point */ #ifdef CONFIG_PPC64 int mmu_pte_psize; /* Page size used for PTE pages */ int mmu_vmemmap_psize; /* Page size used for the virtual mem map */ int book3e_htw_mode; /* HW tablewalk? Value is PPC_HTW_* */ unsigned long linear_map_top; /* Top of linear mapping */ /* * Number of bytes to add to SPRN_SPRG_TLB_EXFRAME on crit/mcheck/debug * exceptions. This is used for bolted and e6500 TLB miss handlers which * do not modify this SPRG in the TLB miss code; for other TLB miss handlers, * this is set to zero. */ int extlb_level_exc; #endif /* CONFIG_PPC64 */ #ifdef CONFIG_PPC_E500 /* next_tlbcam_idx is used to round-robin tlbcam entry assignment */ DEFINE_PER_CPU(int, next_tlbcam_idx); EXPORT_PER_CPU_SYMBOL(next_tlbcam_idx); #endif /* * Base TLB flushing operations: * * - flush_tlb_mm(mm) flushes the specified mm context TLB's * - flush_tlb_page(vma, vmaddr) flushes one page * - flush_tlb_range(vma, start, end) flushes a range of pages * - flush_tlb_kernel_range(start, end) flushes kernel pages * * - local_* variants of page and mm only apply to the current * processor */ #ifndef CONFIG_PPC_8xx /* * These are the base non-SMP variants of page and mm flushing */ void local_flush_tlb_mm(struct mm_struct *mm) { unsigned int pid; preempt_disable(); pid = mm->context.id; if (pid != MMU_NO_CONTEXT) _tlbil_pid(pid); preempt_enable(); } EXPORT_SYMBOL(local_flush_tlb_mm); void __local_flush_tlb_page(struct mm_struct *mm, unsigned long vmaddr, int tsize, int ind) { unsigned int pid; preempt_disable(); pid = mm ? mm->context.id : 0; if (pid != MMU_NO_CONTEXT) _tlbil_va(vmaddr, pid, tsize, ind); preempt_enable(); } void local_flush_tlb_page(struct vm_area_struct *vma, unsigned long vmaddr) { __local_flush_tlb_page(vma ? vma->vm_mm : NULL, vmaddr, mmu_get_tsize(mmu_virtual_psize), 0); } EXPORT_SYMBOL(local_flush_tlb_page); void local_flush_tlb_page_psize(struct mm_struct *mm, unsigned long vmaddr, int psize) { __local_flush_tlb_page(mm, vmaddr, mmu_get_tsize(psize), 0); } EXPORT_SYMBOL(local_flush_tlb_page_psize); #endif /* * And here are the SMP non-local implementations */ #ifdef CONFIG_SMP static DEFINE_RAW_SPINLOCK(tlbivax_lock); struct tlb_flush_param { unsigned long addr; unsigned int pid; unsigned int tsize; unsigned int ind; }; static void do_flush_tlb_mm_ipi(void *param) { struct tlb_flush_param *p = param; _tlbil_pid(p ? p->pid : 0); } static void do_flush_tlb_page_ipi(void *param) { struct tlb_flush_param *p = param; _tlbil_va(p->addr, p->pid, p->tsize, p->ind); } /* Note on invalidations and PID: * * We snapshot the PID with preempt disabled. At this point, it can still * change either because: * - our context is being stolen (PID -> NO_CONTEXT) on another CPU * - we are invaliating some target that isn't currently running here * and is concurrently acquiring a new PID on another CPU * - some other CPU is re-acquiring a lost PID for this mm * etc... * * However, this shouldn't be a problem as we only guarantee * invalidation of TLB entries present prior to this call, so we * don't care about the PID changing, and invalidating a stale PID * is generally harmless. */ void flush_tlb_mm(struct mm_struct *mm) { unsigned int pid; preempt_disable(); pid = mm->context.id; if (unlikely(pid == MMU_NO_CONTEXT)) goto no_context; if (!mm_is_core_local(mm)) { struct tlb_flush_param p = { .pid = pid }; /* Ignores smp_processor_id() even if set. */ smp_call_function_many(mm_cpumask(mm), do_flush_tlb_mm_ipi, &p, 1); } _tlbil_pid(pid); no_context: preempt_enable(); } EXPORT_SYMBOL(flush_tlb_mm); void __flush_tlb_page(struct mm_struct *mm, unsigned long vmaddr, int tsize, int ind) { struct cpumask *cpu_mask; unsigned int pid; /* * This function as well as __local_flush_tlb_page() must only be called * for user contexts. */ if (WARN_ON(!mm)) return; preempt_disable(); pid = mm->context.id; if (unlikely(pid == MMU_NO_CONTEXT)) goto bail; cpu_mask = mm_cpumask(mm); if (!mm_is_core_local(mm)) { /* If broadcast tlbivax is supported, use it */ if (mmu_has_feature(MMU_FTR_USE_TLBIVAX_BCAST)) { int lock = mmu_has_feature(MMU_FTR_LOCK_BCAST_INVAL); if (lock) raw_spin_lock(&tlbivax_lock); _tlbivax_bcast(vmaddr, pid, tsize, ind); if (lock) raw_spin_unlock(&tlbivax_lock); goto bail; } else { struct tlb_flush_param p = { .pid = pid, .addr = vmaddr, .tsize = tsize, .ind = ind, }; /* Ignores smp_processor_id() even if set in cpu_mask */ smp_call_function_many(cpu_mask, do_flush_tlb_page_ipi, &p, 1); } } _tlbil_va(vmaddr, pid, tsize, ind); bail: preempt_enable(); } void flush_tlb_page(struct vm_area_struct *vma, unsigned long vmaddr) { #ifdef CONFIG_HUGETLB_PAGE if (vma && is_vm_hugetlb_page(vma)) flush_hugetlb_page(vma, vmaddr); #endif __flush_tlb_page(vma ? vma->vm_mm : NULL, vmaddr, mmu_get_tsize(mmu_virtual_psize), 0); } EXPORT_SYMBOL(flush_tlb_page); #endif /* CONFIG_SMP */ #ifdef CONFIG_PPC_47x void __init early_init_mmu_47x(void) { #ifdef CONFIG_SMP unsigned long root = of_get_flat_dt_root(); if (of_get_flat_dt_prop(root, "cooperative-partition", NULL)) mmu_clear_feature(MMU_FTR_USE_TLBIVAX_BCAST); #endif /* CONFIG_SMP */ } #endif /* CONFIG_PPC_47x */ /* * Flush kernel TLB entries in the given range */ #ifndef CONFIG_PPC_8xx void flush_tlb_kernel_range(unsigned long start, unsigned long end) { #ifdef CONFIG_SMP preempt_disable(); smp_call_function(do_flush_tlb_mm_ipi, NULL, 1); _tlbil_pid(0); preempt_enable(); #else _tlbil_pid(0); #endif } EXPORT_SYMBOL(flush_tlb_kernel_range); #endif /* * Currently, for range flushing, we just do a full mm flush. This should * be optimized based on a threshold on the size of the range, since * some implementation can stack multiple tlbivax before a tlbsync but * for now, we keep it that way */ void flush_tlb_range(struct vm_area_struct *vma, unsigned long start, unsigned long end) { if (end - start == PAGE_SIZE && !(start & ~PAGE_MASK)) flush_tlb_page(vma, start); else flush_tlb_mm(vma->vm_mm); } EXPORT_SYMBOL(flush_tlb_range); void tlb_flush(struct mmu_gather *tlb) { flush_tlb_mm(tlb->mm); } /* * Below are functions specific to the 64-bit variant of Book3E though that * may change in the future */ #ifdef CONFIG_PPC64 /* * Handling of virtual linear page tables or indirect TLB entries * flushing when PTE pages are freed */ void tlb_flush_pgtable(struct mmu_gather *tlb, unsigned long address) { int tsize = mmu_psize_defs[mmu_pte_psize].enc; if (book3e_htw_mode != PPC_HTW_NONE) { unsigned long start = address & PMD_MASK; unsigned long end = address + PMD_SIZE; unsigned long size = 1UL << mmu_psize_defs[mmu_pte_psize].shift; /* This isn't the most optimal, ideally we would factor out the * while preempt & CPU mask mucking around, or even the IPI but * it will do for now */ while (start < end) { __flush_tlb_page(tlb->mm, start, tsize, 1); start += size; } } else { unsigned long rmask = 0xf000000000000000ul; unsigned long rid = (address & rmask) | 0x1000000000000000ul; unsigned long vpte = address & ~rmask; vpte = (vpte >> (PAGE_SHIFT - 3)) & ~0xffful; vpte |= rid; __flush_tlb_page(tlb->mm, vpte, tsize, 0); } } static void __init setup_page_sizes(void) { unsigned int tlb0cfg; unsigned int tlb0ps; unsigned int eptcfg; int i, psize; #ifdef CONFIG_PPC_E500 unsigned int mmucfg = mfspr(SPRN_MMUCFG); int fsl_mmu = mmu_has_feature(MMU_FTR_TYPE_FSL_E); if (fsl_mmu && (mmucfg & MMUCFG_MAVN) == MMUCFG_MAVN_V1) { unsigned int tlb1cfg = mfspr(SPRN_TLB1CFG); unsigned int min_pg, max_pg; min_pg = (tlb1cfg & TLBnCFG_MINSIZE) >> TLBnCFG_MINSIZE_SHIFT; max_pg = (tlb1cfg & TLBnCFG_MAXSIZE) >> TLBnCFG_MAXSIZE_SHIFT; for (psize = 0; psize < MMU_PAGE_COUNT; ++psize) { struct mmu_psize_def *def; unsigned int shift; def = &mmu_psize_defs[psize]; shift = def->shift; if (shift == 0 || shift & 1) continue; /* adjust to be in terms of 4^shift Kb */ shift = (shift - 10) >> 1; if ((shift >= min_pg) && (shift <= max_pg)) def->flags |= MMU_PAGE_SIZE_DIRECT; } goto out; } if (fsl_mmu && (mmucfg & MMUCFG_MAVN) == MMUCFG_MAVN_V2) { u32 tlb1cfg, tlb1ps; tlb0cfg = mfspr(SPRN_TLB0CFG); tlb1cfg = mfspr(SPRN_TLB1CFG); tlb1ps = mfspr(SPRN_TLB1PS); eptcfg = mfspr(SPRN_EPTCFG); if ((tlb1cfg & TLBnCFG_IND) && (tlb0cfg & TLBnCFG_PT)) book3e_htw_mode = PPC_HTW_E6500; /* * We expect 4K subpage size and unrestricted indirect size. * The lack of a restriction on indirect size is a Freescale * extension, indicated by PSn = 0 but SPSn != 0. */ if (eptcfg != 2) book3e_htw_mode = PPC_HTW_NONE; for (psize = 0; psize < MMU_PAGE_COUNT; ++psize) { struct mmu_psize_def *def = &mmu_psize_defs[psize]; if (!def->shift) continue; if (tlb1ps & (1U << (def->shift - 10))) { def->flags |= MMU_PAGE_SIZE_DIRECT; if (book3e_htw_mode && psize == MMU_PAGE_2M) def->flags |= MMU_PAGE_SIZE_INDIRECT; } } goto out; } #endif tlb0cfg = mfspr(SPRN_TLB0CFG); tlb0ps = mfspr(SPRN_TLB0PS); eptcfg = mfspr(SPRN_EPTCFG); /* Look for supported direct sizes */ for (psize = 0; psize < MMU_PAGE_COUNT; ++psize) { struct mmu_psize_def *def = &mmu_psize_defs[psize]; if (tlb0ps & (1U << (def->shift - 10))) def->flags |= MMU_PAGE_SIZE_DIRECT; } /* Indirect page sizes supported ? */ if ((tlb0cfg & TLBnCFG_IND) == 0 || (tlb0cfg & TLBnCFG_PT) == 0) goto out; book3e_htw_mode = PPC_HTW_IBM; /* Now, we only deal with one IND page size for each * direct size. Hopefully all implementations today are * unambiguous, but we might want to be careful in the * future. */ for (i = 0; i < 3; i++) { unsigned int ps, sps; sps = eptcfg & 0x1f; eptcfg >>= 5; ps = eptcfg & 0x1f; eptcfg >>= 5; if (!ps || !sps) continue; for (psize = 0; psize < MMU_PAGE_COUNT; psize++) { struct mmu_psize_def *def = &mmu_psize_defs[psize]; if (ps == (def->shift - 10)) def->flags |= MMU_PAGE_SIZE_INDIRECT; if (sps == (def->shift - 10)) def->ind = ps + 10; } } out: /* Cleanup array and print summary */ pr_info("MMU: Supported page sizes\n"); for (psize = 0; psize < MMU_PAGE_COUNT; ++psize) { struct mmu_psize_def *def = &mmu_psize_defs[psize]; const char *__page_type_names[] = { "unsupported", "direct", "indirect", "direct & indirect" }; if (def->flags == 0) { def->shift = 0; continue; } pr_info(" %8ld KB as %s\n", 1ul << (def->shift - 10), __page_type_names[def->flags & 0x3]); } } static void __init setup_mmu_htw(void) { /* * If we want to use HW tablewalk, enable it by patching the TLB miss * handlers to branch to the one dedicated to it. */ switch (book3e_htw_mode) { case PPC_HTW_IBM: patch_exception(0x1c0, exc_data_tlb_miss_htw_book3e); patch_exception(0x1e0, exc_instruction_tlb_miss_htw_book3e); break; #ifdef CONFIG_PPC_E500 case PPC_HTW_E6500: extlb_level_exc = EX_TLB_SIZE; patch_exception(0x1c0, exc_data_tlb_miss_e6500_book3e); patch_exception(0x1e0, exc_instruction_tlb_miss_e6500_book3e); break; #endif } pr_info("MMU: Book3E HW tablewalk %s\n", book3e_htw_mode != PPC_HTW_NONE ? "enabled" : "not supported"); } /* * Early initialization of the MMU TLB code */ static void early_init_this_mmu(void) { unsigned int mas4; /* Set MAS4 based on page table setting */ mas4 = 0x4 << MAS4_WIMGED_SHIFT; switch (book3e_htw_mode) { case PPC_HTW_E6500: mas4 |= MAS4_INDD; mas4 |= BOOK3E_PAGESZ_2M << MAS4_TSIZED_SHIFT; mas4 |= MAS4_TLBSELD(1); mmu_pte_psize = MMU_PAGE_2M; break; case PPC_HTW_IBM: mas4 |= MAS4_INDD; mas4 |= BOOK3E_PAGESZ_1M << MAS4_TSIZED_SHIFT; mmu_pte_psize = MMU_PAGE_1M; break; case PPC_HTW_NONE: mas4 |= BOOK3E_PAGESZ_4K << MAS4_TSIZED_SHIFT; mmu_pte_psize = mmu_virtual_psize; break; } mtspr(SPRN_MAS4, mas4); #ifdef CONFIG_PPC_E500 if (mmu_has_feature(MMU_FTR_TYPE_FSL_E)) { unsigned int num_cams; bool map = true; /* use a quarter of the TLBCAM for bolted linear map */ num_cams = (mfspr(SPRN_TLB1CFG) & TLBnCFG_N_ENTRY) / 4; /* * Only do the mapping once per core, or else the * transient mapping would cause problems. */ #ifdef CONFIG_SMP if (hweight32(get_tensr()) > 1) map = false; #endif if (map) linear_map_top = map_mem_in_cams(linear_map_top, num_cams, false, true); } #endif /* A sync won't hurt us after mucking around with * the MMU configuration */ mb(); } static void __init early_init_mmu_global(void) { /* XXX This should be decided at runtime based on supported * page sizes in the TLB, but for now let's assume 16M is * always there and a good fit (which it probably is) * * Freescale booke only supports 4K pages in TLB0, so use that. */ if (mmu_has_feature(MMU_FTR_TYPE_FSL_E)) mmu_vmemmap_psize = MMU_PAGE_4K; else mmu_vmemmap_psize = MMU_PAGE_16M; /* XXX This code only checks for TLB 0 capabilities and doesn't * check what page size combos are supported by the HW. It * also doesn't handle the case where a separate array holds * the IND entries from the array loaded by the PT. */ /* Look for supported page sizes */ setup_page_sizes(); /* Look for HW tablewalk support */ setup_mmu_htw(); #ifdef CONFIG_PPC_E500 if (mmu_has_feature(MMU_FTR_TYPE_FSL_E)) { if (book3e_htw_mode == PPC_HTW_NONE) { extlb_level_exc = EX_TLB_SIZE; patch_exception(0x1c0, exc_data_tlb_miss_bolted_book3e); patch_exception(0x1e0, exc_instruction_tlb_miss_bolted_book3e); } } #endif /* Set the global containing the top of the linear mapping * for use by the TLB miss code */ linear_map_top = memblock_end_of_DRAM(); ioremap_bot = IOREMAP_BASE; } static void __init early_mmu_set_memory_limit(void) { #ifdef CONFIG_PPC_E500 if (mmu_has_feature(MMU_FTR_TYPE_FSL_E)) { /* * Limit memory so we dont have linear faults. * Unlike memblock_set_current_limit, which limits * memory available during early boot, this permanently * reduces the memory available to Linux. We need to * do this because highmem is not supported on 64-bit. */ memblock_enforce_memory_limit(linear_map_top); } #endif memblock_set_current_limit(linear_map_top); } /* boot cpu only */ void __init early_init_mmu(void) { early_init_mmu_global(); early_init_this_mmu(); early_mmu_set_memory_limit(); } void early_init_mmu_secondary(void) { early_init_this_mmu(); } void setup_initial_memory_limit(phys_addr_t first_memblock_base, phys_addr_t first_memblock_size) { /* On non-FSL Embedded 64-bit, we adjust the RMA size to match * the bolted TLB entry. We know for now that only 1G * entries are supported though that may eventually * change. * * on FSL Embedded 64-bit, usually all RAM is bolted, but with * unusual memory sizes it's possible for some RAM to not be mapped * (such RAM is not used at all by Linux, since we don't support * highmem on 64-bit). We limit ppc64_rma_size to what would be * mappable if this memblock is the only one. Additional memblocks * can only increase, not decrease, the amount that ends up getting * mapped. We still limit max to 1G even if we'll eventually map * more. This is due to what the early init code is set up to do. * * We crop it to the size of the first MEMBLOCK to * avoid going over total available memory just in case... */ #ifdef CONFIG_PPC_E500 if (early_mmu_has_feature(MMU_FTR_TYPE_FSL_E)) { unsigned long linear_sz; unsigned int num_cams; /* use a quarter of the TLBCAM for bolted linear map */ num_cams = (mfspr(SPRN_TLB1CFG) & TLBnCFG_N_ENTRY) / 4; linear_sz = map_mem_in_cams(first_memblock_size, num_cams, true, true); ppc64_rma_size = min_t(u64, linear_sz, 0x40000000); } else #endif ppc64_rma_size = min_t(u64, first_memblock_size, 0x40000000); /* Finally limit subsequent allocations */ memblock_set_current_limit(first_memblock_base + ppc64_rma_size); } #else /* ! CONFIG_PPC64 */ void __init early_init_mmu(void) { #ifdef CONFIG_PPC_47x early_init_mmu_47x(); #endif } #endif /* CONFIG_PPC64 */ |