| // SPDX-License-Identifier: GPL-2.0-or-later |
| /* |
| * PowerPC version |
| * 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 |
| * PPC44x/36-bit changes by Matt Porter (mporter@mvista.com) |
| * |
| * Derived from "arch/i386/mm/init.c" |
| * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds |
| */ |
| |
| #include <linux/module.h> |
| #include <linux/sched.h> |
| #include <linux/kernel.h> |
| #include <linux/errno.h> |
| #include <linux/string.h> |
| #include <linux/types.h> |
| #include <linux/mm.h> |
| #include <linux/stddef.h> |
| #include <linux/init.h> |
| #include <linux/highmem.h> |
| #include <linux/initrd.h> |
| #include <linux/pagemap.h> |
| #include <linux/memblock.h> |
| #include <linux/gfp.h> |
| #include <linux/slab.h> |
| #include <linux/hugetlb.h> |
| |
| #include <asm/pgalloc.h> |
| #include <asm/prom.h> |
| #include <asm/io.h> |
| #include <asm/pgtable.h> |
| #include <asm/mmu.h> |
| #include <asm/smp.h> |
| #include <asm/machdep.h> |
| #include <asm/btext.h> |
| #include <asm/tlb.h> |
| #include <asm/sections.h> |
| #include <asm/hugetlb.h> |
| #include <asm/kup.h> |
| #include <asm/kasan.h> |
| |
| #include <mm/mmu_decl.h> |
| |
| #if defined(CONFIG_KERNEL_START_BOOL) || defined(CONFIG_LOWMEM_SIZE_BOOL) |
| /* The amount of lowmem must be within 0xF0000000 - KERNELBASE. */ |
| #if (CONFIG_LOWMEM_SIZE > (0xF0000000 - PAGE_OFFSET)) |
| #error "You must adjust CONFIG_LOWMEM_SIZE or CONFIG_KERNEL_START" |
| #endif |
| #endif |
| #define MAX_LOW_MEM CONFIG_LOWMEM_SIZE |
| |
| phys_addr_t total_memory; |
| phys_addr_t total_lowmem; |
| |
| phys_addr_t memstart_addr = (phys_addr_t)~0ull; |
| EXPORT_SYMBOL(memstart_addr); |
| phys_addr_t kernstart_addr; |
| EXPORT_SYMBOL(kernstart_addr); |
| |
| #ifdef CONFIG_RELOCATABLE |
| /* Used in __va()/__pa() */ |
| long long virt_phys_offset; |
| EXPORT_SYMBOL(virt_phys_offset); |
| #endif |
| |
| phys_addr_t lowmem_end_addr; |
| |
| int boot_mapsize; |
| #ifdef CONFIG_PPC_PMAC |
| unsigned long agp_special_page; |
| EXPORT_SYMBOL(agp_special_page); |
| #endif |
| |
| void MMU_init(void); |
| |
| /* |
| * this tells the system to map all of ram with the segregs |
| * (i.e. page tables) instead of the bats. |
| * -- Cort |
| */ |
| int __map_without_bats; |
| int __map_without_ltlbs; |
| |
| /* max amount of low RAM to map in */ |
| unsigned long __max_low_memory = MAX_LOW_MEM; |
| |
| /* |
| * Check for command-line options that affect what MMU_init will do. |
| */ |
| static void __init MMU_setup(void) |
| { |
| /* Check for nobats option (used in mapin_ram). */ |
| if (strstr(boot_command_line, "nobats")) { |
| __map_without_bats = 1; |
| } |
| |
| if (strstr(boot_command_line, "noltlbs")) { |
| __map_without_ltlbs = 1; |
| } |
| if (debug_pagealloc_enabled()) { |
| __map_without_bats = 1; |
| __map_without_ltlbs = 1; |
| } |
| if (strict_kernel_rwx_enabled() && !IS_ENABLED(CONFIG_PPC_8xx)) |
| __map_without_ltlbs = 1; |
| } |
| |
| /* |
| * MMU_init sets up the basic memory mappings for the kernel, |
| * including both RAM and possibly some I/O regions, |
| * and sets up the page tables and the MMU hardware ready to go. |
| */ |
| void __init MMU_init(void) |
| { |
| if (ppc_md.progress) |
| ppc_md.progress("MMU:enter", 0x111); |
| |
| /* parse args from command line */ |
| MMU_setup(); |
| |
| /* |
| * Reserve gigantic pages for hugetlb. This MUST occur before |
| * lowmem_end_addr is initialized below. |
| */ |
| if (memblock.memory.cnt > 1) { |
| #ifndef CONFIG_WII |
| memblock_enforce_memory_limit(memblock.memory.regions[0].size); |
| pr_warn("Only using first contiguous memory region\n"); |
| #else |
| wii_memory_fixups(); |
| #endif |
| } |
| |
| total_lowmem = total_memory = memblock_end_of_DRAM() - memstart_addr; |
| lowmem_end_addr = memstart_addr + total_lowmem; |
| |
| #ifdef CONFIG_FSL_BOOKE |
| /* Freescale Book-E parts expect lowmem to be mapped by fixed TLB |
| * entries, so we need to adjust lowmem to match the amount we can map |
| * in the fixed entries */ |
| adjust_total_lowmem(); |
| #endif /* CONFIG_FSL_BOOKE */ |
| |
| if (total_lowmem > __max_low_memory) { |
| total_lowmem = __max_low_memory; |
| lowmem_end_addr = memstart_addr + total_lowmem; |
| #ifndef CONFIG_HIGHMEM |
| total_memory = total_lowmem; |
| memblock_enforce_memory_limit(total_lowmem); |
| #endif /* CONFIG_HIGHMEM */ |
| } |
| |
| /* Initialize the MMU hardware */ |
| if (ppc_md.progress) |
| ppc_md.progress("MMU:hw init", 0x300); |
| MMU_init_hw(); |
| |
| /* Map in all of RAM starting at KERNELBASE */ |
| if (ppc_md.progress) |
| ppc_md.progress("MMU:mapin", 0x301); |
| mapin_ram(); |
| |
| /* Initialize early top-down ioremap allocator */ |
| ioremap_bot = IOREMAP_TOP; |
| |
| if (ppc_md.progress) |
| ppc_md.progress("MMU:exit", 0x211); |
| |
| /* From now on, btext is no longer BAT mapped if it was at all */ |
| #ifdef CONFIG_BOOTX_TEXT |
| btext_unmap(); |
| #endif |
| |
| kasan_mmu_init(); |
| |
| setup_kup(); |
| |
| /* Shortly after that, the entire linear mapping will be available */ |
| memblock_set_current_limit(lowmem_end_addr); |
| } |