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