/* * 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #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_START_KERNEL" #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); 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); /* XXX should be in current.h -- paulus */ extern struct task_struct *current_set[NR_CPUS]; /* * 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; /* * This tells the system to allow ioremapping memory marked as reserved. */ int __allow_ioremap_reserved; /* 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. */ void MMU_setup(void) { /* Check for nobats option (used in mapin_ram). */ if (strstr(cmd_line, "nobats")) { __map_without_bats = 1; } if (strstr(cmd_line, "noltlbs")) { __map_without_ltlbs = 1; } #ifdef CONFIG_DEBUG_PAGEALLOC __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(); if (memblock.memory.cnt > 1) { #ifndef CONFIG_WII memblock.memory.cnt = 1; memblock_analyze(); printk(KERN_WARNING "Only using first contiguous memory region"); #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); memblock_analyze(); #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; /* Map in I/O resources */ if (ppc_md.progress) ppc_md.progress("MMU:setio", 0x302); 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); } /* This is only called until mem_init is done. */ void __init *early_get_page(void) { if (init_bootmem_done) return alloc_bootmem_pages(PAGE_SIZE); else return __va(memblock_alloc(PAGE_SIZE, PAGE_SIZE)); } /* Free up now-unused memory */ static void free_sec(unsigned long start, unsigned long end, const char *name) { unsigned long cnt = 0; while (start < end) { ClearPageReserved(virt_to_page(start)); init_page_count(virt_to_page(start)); free_page(start); cnt++; start += PAGE_SIZE; } if (cnt) { printk(" %ldk %s", cnt << (PAGE_SHIFT - 10), name); totalram_pages += cnt; } } void free_initmem(void) { #define FREESEC(TYPE) \ free_sec((unsigned long)(&__ ## TYPE ## _begin), \ (unsigned long)(&__ ## TYPE ## _end), \ #TYPE); printk ("Freeing unused kernel memory:"); FREESEC(init); printk("\n"); ppc_md.progress = NULL; #undef FREESEC } #ifdef CONFIG_BLK_DEV_INITRD void free_initrd_mem(unsigned long start, unsigned long end) { if (start < end) printk ("Freeing initrd memory: %ldk freed\n", (end - start) >> 10); for (; start < end; start += PAGE_SIZE) { ClearPageReserved(virt_to_page(start)); init_page_count(virt_to_page(start)); free_page(start); totalram_pages++; } } #endif #ifdef CONFIG_8xx /* No 8xx specific .c file to put that in ... */ void setup_initial_memory_limit(phys_addr_t first_memblock_base, phys_addr_t first_memblock_size) { /* We don't currently support the first MEMBLOCK not mapping 0 * physical on those processors */ BUG_ON(first_memblock_base != 0); /* 8xx can only access 8MB at the moment */ memblock_set_current_limit(min_t(u64, first_memblock_size, 0x00800000)); } #endif /* CONFIG_8xx */