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Diffstat (limited to 'arch/sh64/mm/init.c')
| -rw-r--r-- | arch/sh64/mm/init.c | 196 |
1 files changed, 196 insertions, 0 deletions
diff --git a/arch/sh64/mm/init.c b/arch/sh64/mm/init.c new file mode 100644 index 00000000000..a65e8bb2c3c --- /dev/null +++ b/arch/sh64/mm/init.c @@ -0,0 +1,196 @@ +/* + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * arch/sh64/mm/init.c + * + * Copyright (C) 2000, 2001 Paolo Alberelli + * Copyright (C) 2003, 2004 Paul Mundt + * + */ + +#include <linux/init.h> +#include <linux/rwsem.h> +#include <linux/mm.h> +#include <linux/swap.h> +#include <linux/bootmem.h> + +#include <asm/mmu_context.h> +#include <asm/page.h> +#include <asm/pgalloc.h> +#include <asm/pgtable.h> +#include <asm/tlb.h> + +#ifdef CONFIG_BLK_DEV_INITRD +#include <linux/blk.h> +#endif + +DEFINE_PER_CPU(struct mmu_gather, mmu_gathers); + +/* + * Cache of MMU context last used. + */ +unsigned long mmu_context_cache; +pgd_t * mmu_pdtp_cache; +int after_bootmem = 0; + +/* + * BAD_PAGE is the page that is used for page faults when linux + * is out-of-memory. Older versions of linux just did a + * do_exit(), but using this instead means there is less risk + * for a process dying in kernel mode, possibly leaving an inode + * unused etc.. + * + * BAD_PAGETABLE is the accompanying page-table: it is initialized + * to point to BAD_PAGE entries. + * + * ZERO_PAGE is a special page that is used for zero-initialized + * data and COW. + */ + +extern unsigned char empty_zero_page[PAGE_SIZE]; +extern unsigned char empty_bad_page[PAGE_SIZE]; +extern pte_t empty_bad_pte_table[PTRS_PER_PTE]; +extern pgd_t swapper_pg_dir[PTRS_PER_PGD]; + +extern char _text, _etext, _edata, __bss_start, _end; +extern char __init_begin, __init_end; + +/* 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) + + +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); + printk("%ld pages in page table cache\n",pgtable_cache_size); +} + +/* + * paging_init() sets up the page tables. + * + * head.S already did a lot to set up address translation for the kernel. + * Here we comes with: + * . MMU enabled + * . ASID set (SR) + * . some 512MB regions being mapped of which the most relevant here is: + * . CACHED segment (ASID 0 [irrelevant], shared AND NOT user) + * . possible variable length regions being mapped as: + * . UNCACHED segment (ASID 0 [irrelevant], shared AND NOT user) + * . All of the memory regions are placed, independently from the platform + * on high addresses, above 0x80000000. + * . swapper_pg_dir is already cleared out by the .space directive + * in any case swapper does not require a real page directory since + * it's all kernel contained. + * + * Those pesky NULL-reference errors in the kernel are then + * dealt with by not mapping address 0x00000000 at all. + * + */ +void __init paging_init(void) +{ + unsigned long zones_size[MAX_NR_ZONES] = {0, 0, 0}; + + pgd_init((unsigned long)swapper_pg_dir); + pgd_init((unsigned long)swapper_pg_dir + + sizeof(pgd_t) * USER_PTRS_PER_PGD); + + mmu_context_cache = MMU_CONTEXT_FIRST_VERSION; + + /* + * All memory is good as ZONE_NORMAL (fall-through) and ZONE_DMA. + */ + zones_size[ZONE_DMA] = MAX_LOW_PFN - START_PFN; + NODE_DATA(0)->node_mem_map = NULL; + free_area_init_node(0, NODE_DATA(0), zones_size, __MEMORY_START >> PAGE_SHIFT, 0); +} + +void __init mem_init(void) +{ + int codesize, reservedpages, datasize, initsize; + int tmp; + + max_mapnr = num_physpages = MAX_LOW_PFN - START_PFN; + high_memory = (void *)__va(MAX_LOW_PFN * PAGE_SIZE); + + /* + * Clear the zero-page. + * This is not required but we might want to re-use + * this very page to pass boot parameters, one day. + */ + memset(empty_zero_page, 0, PAGE_SIZE); + + /* this will put all low memory onto the freelists */ + totalram_pages += free_all_bootmem_node(NODE_DATA(0)); + reservedpages = 0; + for (tmp = 0; tmp < num_physpages; tmp++) + /* + * Only count reserved RAM pages + */ + if (PageReserved(mem_map+tmp)) + reservedpages++; + + after_bootmem = 1; + + 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); +} + +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: %ldk 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 + |