arch/arm/mm/nommu.c

   1 /*
   2  *  linux/arch/arm/mm/nommu.c
   3  *
   4  * ARM uCLinux supporting functions.
   5  */
   6 #include <linux/module.h>
   7 #include <linux/mm.h>
   8 #include <linux/pagemap.h>
   9 #include <linux/bootmem.h>
  10
  11 #include <asm/cacheflush.h>
  12 #include <asm/io.h>
  13 #include <asm/page.h>
  14 #include <asm/mach/arch.h>
  15
  16 #include "mm.h"
  17
  18 extern void _stext, __data_start, _end;
  19
  20 /*
  21  * Reserve the various regions of node 0
  22  */
  23 void __init reserve_node_zero(pg_data_t *pgdat)
  24 {
  25         /*
  26          * Register the kernel text and data with bootmem.
  27          * Note that this can only be in node 0.
  28          */
  29 #ifdef CONFIG_XIP_KERNEL
  30         reserve_bootmem_node(pgdat, __pa(&__data_start), &_end - &__data_start,
  31                         BOOTMEM_DEFAULT);
  32 #else
  33         reserve_bootmem_node(pgdat, __pa(&_stext), &_end - &_stext,
  34                         BOOTMEM_DEFAULT);
  35 #endif
  36
  37         /*
  38          * Register the exception vector page.
  39          * some architectures which the DRAM is the exception vector to trap,
  40          * alloc_page breaks with error, although it is not NULL, but "0."
  41          */
  42         reserve_bootmem_node(pgdat, CONFIG_VECTORS_BASE, PAGE_SIZE,
  43                         BOOTMEM_DEFAULT);
  44 }
  45
  46 /*
  47  * paging_init() sets up the page tables, initialises the zone memory
  48  * maps, and sets up the zero page, bad page and bad page tables.
  49  */
  50 void __init paging_init(struct meminfo *mi, struct machine_desc *mdesc)
  51 {
  52         bootmem_init(mi);
  53 }
  54
  55 /*
  56  * We don't need to do anything here for nommu machines.
  57  */
  58 void setup_mm_for_reboot(char mode)
  59 {
  60 }
  61
  62 void flush_dcache_page(struct page *page)
  63 {
  64         __cpuc_flush_dcache_page(page_address(page));
  65 }
  66 EXPORT_SYMBOL(flush_dcache_page);
  67
  68 void __iomem *__arm_ioremap_pfn(unsigned long pfn, unsigned long offset,
  69                                 size_t size, unsigned int mtype)
  70 {
  71         if (pfn >= (0x100000000ULL >> PAGE_SHIFT))
  72                 return NULL;
  73         return (void __iomem *) (offset + (pfn << PAGE_SHIFT));
  74 }
  75 EXPORT_SYMBOL(__arm_ioremap_pfn);
  76
  77 void __iomem *__arm_ioremap(unsigned long phys_addr, size_t size,
  78                             unsigned int mtype)
  79 {
  80         return (void __iomem *)phys_addr;
  81 }
  82 EXPORT_SYMBOL(__arm_ioremap);
  83
  84 void __iounmap(volatile void __iomem *addr)
  85 {
  86 }
  87 EXPORT_SYMBOL(__iounmap);