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/uaccess.h>
  33 #include <asm/pgtable.h>
  34 #include <asm/pgalloc.h>
  35 #include <asm/dma.h>
  36 #include <asm/tlb.h>
  37 #include <asm/sections.h>
  38
  39 unsigned long highstart_pfn, highend_pfn;
  40
  41 #ifdef CONFIG_MN10300_HAS_ATOMIC_OPS_UNIT
  42 static struct vm_struct user_iomap_vm;
  43 #endif
  44
  45 /*
  46  * set up paging
  47  */
  48 void __init paging_init(void)
  49 {
  50         unsigned long zones_size[MAX_NR_ZONES] = {0,};
  51         pte_t *ppte;
  52         int loop;
  53
  54         /* main kernel space -> RAM mapping is handled as 1:1 transparent by
  55          * the MMU */
  56         memset(swapper_pg_dir, 0, sizeof(swapper_pg_dir));
  57         memset(kernel_vmalloc_ptes, 0, sizeof(kernel_vmalloc_ptes));
  58
  59         /* load the VMALLOC area PTE table addresses into the kernel PGD */
  60         ppte = kernel_vmalloc_ptes;
  61         for (loop = VMALLOC_START / (PAGE_SIZE * PTRS_PER_PTE);
  62              loop < VMALLOC_END / (PAGE_SIZE * PTRS_PER_PTE);
  63              loop++
  64              ) {
  65                 set_pgd(swapper_pg_dir + loop, __pgd(__pa(ppte) | _PAGE_TABLE));
  66                 ppte += PAGE_SIZE / sizeof(pte_t);
  67         }
  68
  69         /* declare the sizes of the RAM zones (only use the normal zone) */
  70         zones_size[ZONE_NORMAL] =
  71                 contig_page_data.bdata->node_low_pfn -
  72                 contig_page_data.bdata->node_min_pfn;
  73
  74         /* pass the memory from the bootmem allocator to the main allocator */
  75         free_area_init(zones_size);
  76
  77 #ifdef CONFIG_MN10300_HAS_ATOMIC_OPS_UNIT
  78         /* The Atomic Operation Unit registers need to be mapped to userspace
  79          * for all processes.  The following uses vm_area_register_early() to
  80          * reserve the first page of the vmalloc area and sets the pte for that
  81          * page.
  82          *
  83          * glibc hardcodes this virtual mapping, so we're pretty much stuck with
  84          * it from now on.
  85          */
  86         user_iomap_vm.flags = VM_USERMAP;
  87         user_iomap_vm.size = 1 << PAGE_SHIFT;
  88         vm_area_register_early(&user_iomap_vm, PAGE_SIZE);
  89         ppte = kernel_vmalloc_ptes;
  90         set_pte(ppte, pfn_pte(USER_ATOMIC_OPS_PAGE_ADDR >> PAGE_SHIFT,
  91                               PAGE_USERIO));
  92 #endif
  93
  94         local_flush_tlb_all();
  95 }
  96
  97 /*
  98  * transfer all the memory from the bootmem allocator to the runtime allocator
  99  */
 100 void __init mem_init(void)
 101 {
 102         BUG_ON(!mem_map);
 103
 104 #define START_PFN       (contig_page_data.bdata->node_min_pfn)
 105 #define MAX_LOW_PFN     (contig_page_data.bdata->node_low_pfn)
 106
 107         max_mapnr = MAX_LOW_PFN - START_PFN;
 108         high_memory = (void *) __va(MAX_LOW_PFN * PAGE_SIZE);
 109
 110         /* clear the zero-page */
 111         memset(empty_zero_page, 0, PAGE_SIZE);
 112
 113         /* this will put all low memory onto the freelists */
 114         free_all_bootmem();
 115
 116         mem_init_print_info(NULL);
 117 }
 118
 119 /*
 120  * recycle memory containing stuff only required for initialisation
 121  */
 122 void free_initmem(void)
 123 {
 124         free_initmem_default(POISON_FREE_INITMEM);
 125 }
 126
 127 /*
 128  * dispose of the memory on which the initial ramdisk resided
 129  */
 130 #ifdef CONFIG_BLK_DEV_INITRD
 131 void free_initrd_mem(unsigned long start, unsigned long end)
 132 {
 133         free_reserved_area((void *)start, (void *)end, POISON_FREE_INITMEM,
 134                            "initrd");
 135 }
 136 #endif