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Diffstat (limited to 'arch/sh/mm/init.c')
| -rw-r--r-- | arch/sh/mm/init.c | 313 |
1 files changed, 313 insertions, 0 deletions
diff --git a/arch/sh/mm/init.c b/arch/sh/mm/init.c new file mode 100644 index 000000000000..4e9c854845a4 --- /dev/null +++ b/arch/sh/mm/init.c @@ -0,0 +1,313 @@ +/* $Id: init.c,v 1.19 2004/02/21 04:42:16 kkojima Exp $ + * + * linux/arch/sh/mm/init.c + * + * Copyright (C) 1999 Niibe Yutaka + * Copyright (C) 2002, 2004 Paul Mundt + * + * Based on linux/arch/i386/mm/init.c: + * Copyright (C) 1995 Linus Torvalds + */ + +#include <linux/config.h> +#include <linux/signal.h> +#include <linux/sched.h> +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/string.h> +#include <linux/types.h> +#include <linux/ptrace.h> +#include <linux/mman.h> +#include <linux/mm.h> +#include <linux/swap.h> +#include <linux/smp.h> +#include <linux/init.h> +#include <linux/highmem.h> +#include <linux/bootmem.h> +#include <linux/pagemap.h> + +#include <asm/processor.h> +#include <asm/system.h> +#include <asm/uaccess.h> +#include <asm/pgtable.h> +#include <asm/pgalloc.h> +#include <asm/mmu_context.h> +#include <asm/io.h> +#include <asm/tlb.h> +#include <asm/cacheflush.h> +#include <asm/cache.h> + +DEFINE_PER_CPU(struct mmu_gather, mmu_gathers); +pgd_t swapper_pg_dir[PTRS_PER_PGD]; + +/* + * Cache of MMU context last used. + */ +unsigned long mmu_context_cache = NO_CONTEXT; + +#ifdef CONFIG_MMU +/* It'd be good if these lines were in the standard header file. */ +#define START_PFN (NODE_DATA(0)->bdata->node_boot_start >> PAGE_SHIFT) +#define MAX_LOW_PFN (NODE_DATA(0)->bdata->node_low_pfn) +#endif + +#ifdef CONFIG_DISCONTIGMEM +pg_data_t discontig_page_data[MAX_NUMNODES]; +bootmem_data_t discontig_node_bdata[MAX_NUMNODES]; +#endif + +void (*copy_page)(void *from, void *to); +void (*clear_page)(void *to); + +void show_mem(void) +{ + int i, total = 0, reserved = 0; + int shared = 0, cached = 0; + + printk("Mem-info:\n"); + show_free_areas(); + printk("Free swap: %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10)); + i = max_mapnr; + while (i-- > 0) { + total++; + if (PageReserved(mem_map+i)) + reserved++; + else if (PageSwapCache(mem_map+i)) + cached++; + else if (page_count(mem_map+i)) + shared += page_count(mem_map+i) - 1; + } + printk("%d pages of RAM\n",total); + printk("%d reserved pages\n",reserved); + printk("%d pages shared\n",shared); + printk("%d pages swap cached\n",cached); +} + +static void set_pte_phys(unsigned long addr, unsigned long phys, pgprot_t prot) +{ + pgd_t *pgd; + pmd_t *pmd; + pte_t *pte; + + pgd = swapper_pg_dir + pgd_index(addr); + if (pgd_none(*pgd)) { + pgd_ERROR(*pgd); + return; + } + + pmd = pmd_offset(pgd, addr); + if (pmd_none(*pmd)) { + pte = (pte_t *)get_zeroed_page(GFP_ATOMIC); + set_pmd(pmd, __pmd(__pa(pte) | _KERNPG_TABLE | _PAGE_USER)); + if (pte != pte_offset_kernel(pmd, 0)) { + pmd_ERROR(*pmd); + return; + } + } + + pte = pte_offset_kernel(pmd, addr); + if (!pte_none(*pte)) { + pte_ERROR(*pte); + return; + } + + set_pte(pte, pfn_pte(phys >> PAGE_SHIFT, prot)); + + __flush_tlb_page(get_asid(), addr); +} + +/* + * As a performance optimization, other platforms preserve the fixmap mapping + * across a context switch, we don't presently do this, but this could be done + * in a similar fashion as to the wired TLB interface that sh64 uses (by way + * of the memorry mapped UTLB configuration) -- this unfortunately forces us to + * give up a TLB entry for each mapping we want to preserve. While this may be + * viable for a small number of fixmaps, it's not particularly useful for + * everything and needs to be carefully evaluated. (ie, we may want this for + * the vsyscall page). + * + * XXX: Perhaps add a _PAGE_WIRED flag or something similar that we can pass + * in at __set_fixmap() time to determine the appropriate behavior to follow. + * + * -- PFM. + */ +void __set_fixmap(enum fixed_addresses idx, unsigned long phys, pgprot_t prot) +{ + unsigned long address = __fix_to_virt(idx); + + if (idx >= __end_of_fixed_addresses) { + BUG(); + return; + } + + set_pte_phys(address, phys, prot); +} + +/* References to section boundaries */ + +extern char _text, _etext, _edata, __bss_start, _end; +extern char __init_begin, __init_end; + +/* + * paging_init() sets up the page tables + * + * This routines also unmaps the page at virtual kernel address 0, so + * that we can trap those pesky NULL-reference errors in the kernel. + */ +void __init paging_init(void) +{ + unsigned long zones_size[MAX_NR_ZONES] = { 0, }; + + /* + * Setup some defaults for the zone sizes.. these should be safe + * regardless of distcontiguous memory or MMU settings. + */ + zones_size[ZONE_DMA] = 0 >> PAGE_SHIFT; + zones_size[ZONE_NORMAL] = __MEMORY_SIZE >> PAGE_SHIFT; +#ifdef CONFIG_HIGHMEM + zones_size[ZONE_HIGHMEM] = 0 >> PAGE_SHIFT; +#endif + +#ifdef CONFIG_MMU + /* + * If we have an MMU, and want to be using it .. we need to adjust + * the zone sizes accordingly, in addition to turning it on. + */ + { + unsigned long max_dma, low, start_pfn; + pgd_t *pg_dir; + int i; + + /* We don't need kernel mapping as hardware support that. */ + pg_dir = swapper_pg_dir; + + for (i = 0; i < PTRS_PER_PGD; i++) + pgd_val(pg_dir[i]) = 0; + + /* Turn on the MMU */ + enable_mmu(); + + /* Fixup the zone sizes */ + start_pfn = START_PFN; + max_dma = virt_to_phys((char *)MAX_DMA_ADDRESS) >> PAGE_SHIFT; + low = MAX_LOW_PFN; + + if (low < max_dma) { + zones_size[ZONE_DMA] = low - start_pfn; + zones_size[ZONE_NORMAL] = 0; + } else { + zones_size[ZONE_DMA] = max_dma - start_pfn; + zones_size[ZONE_NORMAL] = low - max_dma; + } + } + +#elif defined(CONFIG_CPU_SH3) || defined(CONFIG_CPU_SH4) + /* + * If we don't have CONFIG_MMU set and the processor in question + * still has an MMU, care needs to be taken to make sure it doesn't + * stay on.. Since the boot loader could have potentially already + * turned it on, and we clearly don't want it, we simply turn it off. + * + * We don't need to do anything special for the zone sizes, since the + * default values that were already configured up above should be + * satisfactory. + */ + disable_mmu(); +#endif + NODE_DATA(0)->node_mem_map = NULL; + free_area_init_node(0, NODE_DATA(0), zones_size, __MEMORY_START >> PAGE_SHIFT, 0); + +#ifdef CONFIG_DISCONTIGMEM + /* + * And for discontig, do some more fixups on the zone sizes.. + */ + zones_size[ZONE_DMA] = __MEMORY_SIZE_2ND >> PAGE_SHIFT; + zones_size[ZONE_NORMAL] = 0; + free_area_init_node(1, NODE_DATA(1), zones_size, __MEMORY_START_2ND >> PAGE_SHIFT, 0); +#endif +} + +void __init mem_init(void) +{ + extern unsigned long empty_zero_page[1024]; + int codesize, reservedpages, datasize, initsize; + int tmp; + extern unsigned long memory_start; + +#ifdef CONFIG_MMU + high_memory = (void *)__va(MAX_LOW_PFN * PAGE_SIZE); +#else + extern unsigned long memory_end; + + high_memory = (void *)(memory_end & PAGE_MASK); +#endif + + max_mapnr = num_physpages = MAP_NR(high_memory) - MAP_NR(memory_start); + + /* clear the zero-page */ + memset(empty_zero_page, 0, PAGE_SIZE); + __flush_wback_region(empty_zero_page, PAGE_SIZE); + + /* + * Setup wrappers for copy/clear_page(), these will get overridden + * later in the boot process if a better method is available. + */ + copy_page = copy_page_slow; + clear_page = clear_page_slow; + + /* this will put all low memory onto the freelists */ + totalram_pages += free_all_bootmem_node(NODE_DATA(0)); +#ifdef CONFIG_DISCONTIGMEM + totalram_pages += free_all_bootmem_node(NODE_DATA(1)); +#endif + reservedpages = 0; + for (tmp = 0; tmp < num_physpages; tmp++) + /* + * Only count reserved RAM pages + */ + if (PageReserved(mem_map+tmp)) + reservedpages++; + + codesize = (unsigned long) &_etext - (unsigned long) &_text; + datasize = (unsigned long) &_edata - (unsigned long) &_etext; + initsize = (unsigned long) &__init_end - (unsigned long) &__init_begin; + + printk("Memory: %luk/%luk available (%dk kernel code, %dk reserved, %dk data, %dk init)\n", + (unsigned long) nr_free_pages() << (PAGE_SHIFT-10), + max_mapnr << (PAGE_SHIFT-10), + codesize >> 10, + reservedpages << (PAGE_SHIFT-10), + datasize >> 10, + initsize >> 10); + + p3_cache_init(); +} + +void free_initmem(void) +{ + unsigned long addr; + + addr = (unsigned long)(&__init_begin); + for (; addr < (unsigned long)(&__init_end); addr += PAGE_SIZE) { + ClearPageReserved(virt_to_page(addr)); + set_page_count(virt_to_page(addr), 1); + free_page(addr); + totalram_pages++; + } + printk ("Freeing unused kernel memory: %dk freed\n", (&__init_end - &__init_begin) >> 10); +} + +#ifdef CONFIG_BLK_DEV_INITRD +void free_initrd_mem(unsigned long start, unsigned long end) +{ + unsigned long p; + for (p = start; p < end; p += PAGE_SIZE) { + ClearPageReserved(virt_to_page(p)); + set_page_count(virt_to_page(p), 1); + free_page(p); + totalram_pages++; + } + printk ("Freeing initrd memory: %ldk freed\n", (end - start) >> 10); +} +#endif + |