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