/* * 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 * Amiga/APUS changes by Jesper Skov (jskov@cygnus.co.uk). * 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 ammount of lowmem must be within 0xF0000000 - KERNELBASE. */ #if (CONFIG_LOWMEM_SIZE > (0xF0000000 - KERNELBASE)) #error "You must adjust CONFIG_LOWMEM_SIZE or CONFIG_START_KERNEL" #endif #endif #define MAX_LOW_MEM CONFIG_LOWMEM_SIZE DEFINE_PER_CPU(struct mmu_gather, mmu_gathers); unsigned long total_memory; unsigned long total_lowmem; unsigned long ppc_memstart; unsigned long ppc_memoffset = PAGE_OFFSET; int boot_mapsize; #ifdef CONFIG_PPC_PMAC unsigned long agp_special_page; EXPORT_SYMBOL(agp_special_page); #endif #ifdef CONFIG_HIGHMEM pte_t *kmap_pte; pgprot_t kmap_prot; EXPORT_SYMBOL(kmap_prot); EXPORT_SYMBOL(kmap_pte); #endif void MMU_init(void); /* XXX should be in current.h -- paulus */ extern struct task_struct *current_set[NR_CPUS]; extern int init_bootmem_done; /* * 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; /* * limit of what is accessible with initial MMU setup - * 256MB usually, but only 16MB on 601. */ unsigned long __initial_memory_limit = 0x10000000; /* * 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); /* 601 can only access 16MB at the moment */ if (PVR_VER(mfspr(SPRN_PVR)) == 1) __initial_memory_limit = 0x01000000; /* parse args from command line */ MMU_setup(); if (lmb.memory.cnt > 1) { lmb.memory.cnt = 1; lmb_analyze(); printk(KERN_WARNING "Only using first contiguous memory region"); } total_memory = lmb_end_of_DRAM(); total_lowmem = total_memory; #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; #ifndef CONFIG_HIGHMEM total_memory = total_lowmem; lmb_enforce_memory_limit(total_lowmem); lmb_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(); #ifdef CONFIG_HIGHMEM ioremap_base = PKMAP_BASE; #else ioremap_base = 0xfe000000UL; /* for now, could be 0xfffff000 */ #endif /* CONFIG_HIGHMEM */ ioremap_bot = ioremap_base; /* Map in I/O resources */ if (ppc_md.progress) ppc_md.progress("MMU:setio", 0x302); if (ppc_md.setup_io_mappings) ppc_md.setup_io_mappings(); /* Initialize the context management stuff */ mmu_context_init(); 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 } /* This is only called until mem_init is done. */ void __init *early_get_page(void) { void *p; if (init_bootmem_done) { p = alloc_bootmem_pages(PAGE_SIZE); } else { p = __va(lmb_alloc_base(PAGE_SIZE, PAGE_SIZE, __initial_memory_limit)); } return p; } /* 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