/* *  arch/s390/mm/init.c * *  S390 version *    Copyright (C) 1999 IBM Deutschland Entwicklung GmbH, IBM Corporation *    Author(s): Hartmut Penner (hp@de.ibm.com) * *  Derived from "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>#ifdef CONFIG_BLK_DEV_INITRD#include <linux/blk.h>#endif#include <linux/pagemap.h>#include <linux/bootmem.h>#include <asm/processor.h>#include <asm/system.h>#include <asm/uaccess.h>#include <asm/pgtable.h>#include <asm/pgalloc.h>#include <asm/dma.h>#include <asm/lowcore.h>#include <asm/tlb.h>mmu_gather_t mmu_gathers[NR_CPUS];static unsigned long totalram_pages;pgd_t swapper_pg_dir[PTRS_PER_PGD] __attribute__((__aligned__(PAGE_SIZE)));char  empty_zero_page[PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE)));int do_check_pgt_cache(int low, int high){        int freed = 0;        if(pgtable_cache_size > high) {                do {                        if(pgd_quicklist) {                                free_pgd_slow(get_pgd_fast());				freed += 2;			}                        if(pmd_quicklist) {                                pmd_free_slow(pmd_alloc_one_fast(NULL, 0));				freed++;			}                        if(pte_quicklist) {                                pte_free_slow(pte_alloc_one_fast(NULL, 0));				freed++;			}                } while(pgtable_cache_size > low);        }        return freed;}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:       %6dkB\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 += atomic_read(&mem_map[i].count) - 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);        show_buffers();}/* References to section boundaries */extern unsigned long _text;extern unsigned long _etext;extern unsigned long _edata;extern unsigned long __bss_start;extern unsigned long _end;extern unsigned long __init_begin;extern unsigned long __init_end;/* * paging_init() sets up the page tables - note that the first 4MB are * already mapped by head.S. * paging_init will erase this initial mapping */unsigned long last_valid_pfn;void __init paging_init(void){        pgd_t * pg_dir;        pte_t * pg_table;        pte_t   pte;	int     i;        unsigned long tmp;        unsigned long address=0;        unsigned long pgdir_k = (__pa(swapper_pg_dir) & PAGE_MASK) | _KERNSEG_TABLE;	unsigned long end_mem = (unsigned long) __va(max_low_pfn*PAGE_SIZE);        static const int ssm_mask = 0x04000000L;	/* unmap whole virtual address space */        pg_dir = swapper_pg_dir;	for (i=0;i<KERNEL_PGD_PTRS;i++) 	        pmd_clear((pmd_t*)pg_dir++);	/*	 * map whole physical memory to virtual memory (identity mapping) 	 */        pg_dir = swapper_pg_dir;        while (address < end_mem) {                /*                 * pg_table is physical at this point                 */		pg_table = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE);                pg_dir->pgd0 =  (_PAGE_TABLE | __pa(pg_table));                pg_dir->pgd1 =  (_PAGE_TABLE | (__pa(pg_table)+1024));                pg_dir->pgd2 =  (_PAGE_TABLE | (__pa(pg_table)+2048));                pg_dir->pgd3 =  (_PAGE_TABLE | (__pa(pg_table)+3072));                pg_dir++;                for (tmp = 0 ; tmp < PTRS_PER_PTE ; tmp++,pg_table++) {                        pte = mk_pte_phys(address, PAGE_KERNEL);                        if (address >= end_mem)                                pte_clear(&pte);                        set_pte(pg_table, pte);                        address += PAGE_SIZE;                }        }        /* enable virtual mapping in kernel mode */        __asm__ __volatile__("    LCTL  1,1,%0\n"                             "    LCTL  7,7,%0\n"                             "    LCTL  13,13,%0\n"                             "    SSM   %1" 			     : : "m" (pgdir_k), "m" (ssm_mask));        local_flush_tlb();	{		unsigned long zones_size[MAX_NR_ZONES] = { 0, 0, 0};		zones_size[ZONE_DMA] = max_low_pfn;		free_area_init(zones_size);	}        return;}void __init mem_init(void){	int codesize, reservedpages, datasize, initsize;        max_mapnr = num_physpages = max_low_pfn;        high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);        /* clear the zero-page */        memset(empty_zero_page, 0, PAGE_SIZE);	/* this will put all low memory onto the freelists */	totalram_pages += free_all_bootmem();	reservedpages = 0;	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 (KERN_INFO "Freeing unused kernel memory: %dk freed\n",		(&__init_end - &__init_begin) >> 10);}#ifdef CONFIG_BLK_DEV_INITRDvoid free_initrd_mem(unsigned long start, unsigned long end){        if (start < end)                printk (KERN_INFO "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++;        }}#endifvoid si_meminfo(struct sysinfo *val){	val->totalram = totalram_pages;	val->sharedram = 0;	val->freeram = nr_free_pages();	val->bufferram = atomic_read(&buffermem_pages);	val->totalhigh = 0;	val->freehigh = 0;	val->mem_unit = PAGE_SIZE;}