diff options
Diffstat (limited to 'arch/powerpc/mm/init_32.c')
| -rw-r--r-- | arch/powerpc/mm/init_32.c | 187 |
1 files changed, 187 insertions, 0 deletions
diff --git a/arch/powerpc/mm/init_32.c b/arch/powerpc/mm/init_32.c new file mode 100644 index 000000000..3e59e5d64 --- /dev/null +++ b/arch/powerpc/mm/init_32.c @@ -0,0 +1,187 @@ +/* + * 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 + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + * + */ + +#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 "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; + } +#ifdef CONFIG_STRICT_KERNEL_RWX + if (rodata_enabled) { + __map_without_bats = 1; + __map_without_ltlbs = 1; + } +#endif +} + +/* + * 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 + + /* Shortly after that, the entire linear mapping will be available */ + memblock_set_current_limit(lowmem_end_addr); +} |