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Diffstat (limited to 'arch/powerpc/mm/init_32.c')
| -rw-r--r-- | arch/powerpc/mm/init_32.c | 251 |
1 files changed, 251 insertions, 0 deletions
diff --git a/arch/powerpc/mm/init_32.c b/arch/powerpc/mm/init_32.c new file mode 100644 index 000000000000..7d4b8b5f0606 --- /dev/null +++ b/arch/powerpc/mm/init_32.c @@ -0,0 +1,251 @@ +/* + * 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 <linux/config.h> +#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/bootmem.h> +#include <linux/highmem.h> +#include <linux/initrd.h> +#include <linux/pagemap.h> + +#include <asm/pgalloc.h> +#include <asm/prom.h> +#include <asm/io.h> +#include <asm/mmu_context.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/prom.h> +#include <asm/lmb.h> +#include <asm/sections.h> + +#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; + } +} + +/* + * 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); +} + +/* 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)); + set_page_count(virt_to_page(start), 1); + 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)); + set_page_count(virt_to_page(start), 1); + free_page(start); + totalram_pages++; + } +} +#endif |