// SPDX-License-Identifier: GPL-2.0-or-later /* * Copyright 2008,2009 Ben Herrenschmidt * 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 #include #include #include #include #include #include #include #include #include #include #include /* 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 */ static 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; /* * 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].shift - 10; 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 eptcfg; int psize; unsigned int mmucfg = mfspr(SPRN_MMUCFG); if ((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 ((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; } 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]); } } /* * 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_NONE: mas4 |= BOOK3E_PAGESZ_4K << MAS4_TSIZED_SHIFT; mmu_pte_psize = mmu_virtual_psize; break; } mtspr(SPRN_MAS4, mas4); 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); /* A sync won't hurt us after mucking around with * the MMU configuration */ mb(); } static void __init early_init_mmu_global(void) { /* * Freescale booke only supports 4K pages in TLB0, so use that. */ mmu_vmemmap_psize = MMU_PAGE_4K; /* 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(); /* * If we want to use HW tablewalk, enable it by patching the TLB miss * handlers to branch to the one dedicated to it. */ extlb_level_exc = EX_TLB_SIZE; switch (book3e_htw_mode) { case PPC_HTW_E6500: patch_exception(0x1c0, exc_data_tlb_miss_e6500_book3e); patch_exception(0x1e0, exc_instruction_tlb_miss_e6500_book3e); break; } pr_info("MMU: Book3E HW tablewalk %s\n", book3e_htw_mode != PPC_HTW_NONE ? "enabled" : "not supported"); /* 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) { /* * 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); 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 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... */ 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); /* Finally limit subsequent allocations */ memblock_set_current_limit(first_memblock_base + ppc64_rma_size); }