arch/mn10300/mm/init.c

   1 /* MN10300 Memory management initialisation
   2  *
   3  * Copyright (C) 2007 Matsushita Electric Industrial Co., Ltd.
   4  * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
   5  * Modified by David Howells (dhowells@redhat.com)
   6  *
   7  * This program is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU General Public Licence
   9  * as published by the Free Software Foundation; either version
  10  * 2 of the Licence, or (at your option) any later version.
  11  */
  12 #include <linux/signal.h>
  13 #include <linux/sched.h>
  14 #include <linux/kernel.h>
  15 #include <linux/errno.h>
  16 #include <linux/string.h>
  17 #include <linux/types.h>
  18 #include <linux/ptrace.h>
  19 #include <linux/mman.h>
  20 #include <linux/fs.h>
  21 #include <linux/mm.h>
  22 #include <linux/swap.h>
  23 #include <linux/smp.h>
  24 #include <linux/init.h>
  25 #include <linux/initrd.h>
  26 #include <linux/highmem.h>
  27 #include <linux/pagemap.h>
  28 #include <linux/bootmem.h>
  29 #include <linux/gfp.h>
  30
  31 #include <asm/processor.h>
  32 #include <asm/system.h>
  33 #include <asm/uaccess.h>
  34 #include <asm/pgtable.h>
  35 #include <asm/pgalloc.h>
  36 #include <asm/dma.h>
  37 #include <asm/tlb.h>
  38 #include <asm/sections.h>
  39
  40 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
  41
  42 unsigned long highstart_pfn, highend_pfn;
  43
  44 #ifdef CONFIG_MN10300_HAS_ATOMIC_OPS_UNIT
  45 static struct vm_struct user_iomap_vm;
  46 #endif
  47
  48 /*
  49  * set up paging
  50  */
  51 void __init paging_init(void)
  52 {
  53         unsigned long zones_size[MAX_NR_ZONES] = {0,};
  54         pte_t *ppte;
  55         int loop;
  56
  57         /* main kernel space -> RAM mapping is handled as 1:1 transparent by
  58          * the MMU */
  59         memset(swapper_pg_dir, 0, sizeof(swapper_pg_dir));
  60         memset(kernel_vmalloc_ptes, 0, sizeof(kernel_vmalloc_ptes));
  61
  62         /* load the VMALLOC area PTE table addresses into the kernel PGD */
  63         ppte = kernel_vmalloc_ptes;
  64         for (loop = VMALLOC_START / (PAGE_SIZE * PTRS_PER_PTE);
  65              loop < VMALLOC_END / (PAGE_SIZE * PTRS_PER_PTE);
  66              loop++
  67              ) {
  68                 set_pgd(swapper_pg_dir + loop, __pgd(__pa(ppte) | _PAGE_TABLE));
  69                 ppte += PAGE_SIZE / sizeof(pte_t);
  70         }
  71
  72         /* declare the sizes of the RAM zones (only use the normal zone) */
  73         zones_size[ZONE_NORMAL] =
  74                 contig_page_data.bdata->node_low_pfn -
  75                 contig_page_data.bdata->node_min_pfn;
  76
  77         /* pass the memory from the bootmem allocator to the main allocator */
  78         free_area_init(zones_size);
  79
  80 #ifdef CONFIG_MN10300_HAS_ATOMIC_OPS_UNIT
  81         /* The Atomic Operation Unit registers need to be mapped to userspace
  82          * for all processes.  The following uses vm_area_register_early() to
  83          * reserve the first page of the vmalloc area and sets the pte for that
  84          * page.
  85          *
  86          * glibc hardcodes this virtual mapping, so we're pretty much stuck with
  87          * it from now on.
  88          */
  89         user_iomap_vm.flags = VM_USERMAP;
  90         user_iomap_vm.size = 1 << PAGE_SHIFT;
  91         vm_area_register_early(&user_iomap_vm, PAGE_SIZE);
  92         ppte = kernel_vmalloc_ptes;
  93         set_pte(ppte, pfn_pte(USER_ATOMIC_OPS_PAGE_ADDR >> PAGE_SHIFT,
  94                               PAGE_USERIO));
  95 #endif
  96
  97         local_flush_tlb_all();
  98 }
  99
 100 /*
 101  * transfer all the memory from the bootmem allocator to the runtime allocator
 102  */
 103 void __init mem_init(void)
 104 {
 105         int codesize, reservedpages, datasize, initsize;
 106         int tmp;
 107
 108         BUG_ON(!mem_map);
 109
 110 #define START_PFN       (contig_page_data.bdata->node_min_pfn)
 111 #define MAX_LOW_PFN     (contig_page_data.bdata->node_low_pfn)
 112
 113         max_mapnr = num_physpages = MAX_LOW_PFN - START_PFN;
 114         high_memory = (void *) __va(MAX_LOW_PFN * PAGE_SIZE);
 115
 116         /* clear the zero-page */
 117         memset(empty_zero_page, 0, PAGE_SIZE);
 118
 119         /* this will put all low memory onto the freelists */
 120         totalram_pages += free_all_bootmem();
 121
 122         reservedpages = 0;
 123         for (tmp = 0; tmp < num_physpages; tmp++)
 124                 if (PageReserved(&mem_map[tmp]))
 125                         reservedpages++;
 126
 127         codesize =  (unsigned long) &_etext - (unsigned long) &_stext;
 128         datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
 129         initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
 130
 131         printk(KERN_INFO
 132                "Memory: %luk/%luk available"
 133                " (%dk kernel code, %dk reserved, %dk data, %dk init,"
 134                " %ldk highmem)\n",
 135                nr_free_pages() << (PAGE_SHIFT - 10),
 136                max_mapnr << (PAGE_SHIFT - 10),
 137                codesize >> 10,
 138                reservedpages << (PAGE_SHIFT - 10),
 139                datasize >> 10,
 140                initsize >> 10,
 141                totalhigh_pages << (PAGE_SHIFT - 10));
 142 }
 143
 144 /*
 145  *
 146  */
 147 void free_init_pages(char *what, unsigned long begin, unsigned long end)
 148 {
 149         unsigned long addr;
 150
 151         for (addr = begin; addr < end; addr += PAGE_SIZE) {
 152                 ClearPageReserved(virt_to_page(addr));
 153                 init_page_count(virt_to_page(addr));
 154                 memset((void *) addr, 0xcc, PAGE_SIZE);
 155                 free_page(addr);
 156                 totalram_pages++;
 157         }
 158         printk(KERN_INFO "Freeing %s: %ldk freed\n", what, (end - begin) >> 10);
 159 }
 160
 161 /*
 162  * recycle memory containing stuff only required for initialisation
 163  */
 164 void free_initmem(void)
 165 {
 166         free_init_pages("unused kernel memory",
 167                         (unsigned long) &__init_begin,
 168                         (unsigned long) &__init_end);
 169 }
 170
 171 /*
 172  * dispose of the memory on which the initial ramdisk resided
 173  */
 174 #ifdef CONFIG_BLK_DEV_INITRD
 175 void free_initrd_mem(unsigned long start, unsigned long end)
 176 {
 177         free_init_pages("initrd memory", start, end);
 178 }
 179 #endif