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/setup.h>
  16 #include <asm/mach/arch.h>
  17
  18 #include "mm.h"
  19
  20 /*
  21  * Reserve the various regions
  22  */
  23 void __init reserve_special_regions(void)
  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(__pa(_data), _end - _data, BOOTMEM_DEFAULT);
  31 #else
  32         reserve_bootmem(__pa(_stext), _end - _stext, 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(CONFIG_VECTORS_BASE, PAGE_SIZE, BOOTMEM_DEFAULT);
  41 }
  42
  43 /*
  44  * paging_init() sets up the page tables, initialises the zone memory
  45  * maps, and sets up the zero page, bad page and bad page tables.
  46  */
  47 void __init paging_init(struct machine_desc *mdesc)
  48 {
  49         bootmem_init();
  50 }
  51
  52 /*
  53  * We don't need to do anything here for nommu machines.
  54  */
  55 void setup_mm_for_reboot(char mode)
  56 {
  57 }
  58
  59 void flush_dcache_page(struct page *page)
  60 {
  61         __cpuc_flush_dcache_area(page_address(page), PAGE_SIZE);
  62 }
  63 EXPORT_SYMBOL(flush_dcache_page);
  64
  65 void copy_to_user_page(struct vm_area_struct *vma, struct page *page,
  66                        unsigned long uaddr, void *dst, const void *src,
  67                        unsigned long len)
  68 {
  69         memcpy(dst, src, len);
  70         if (vma->vm_flags & VM_EXEC)
  71                 __cpuc_coherent_user_range(uaddr, uaddr + len);
  72 }
  73
  74 void __iomem *__arm_ioremap_pfn(unsigned long pfn, unsigned long offset,
  75                                 size_t size, unsigned int mtype)
  76 {
  77         if (pfn >= (0x100000000ULL >> PAGE_SHIFT))
  78                 return NULL;
  79         return (void __iomem *) (offset + (pfn << PAGE_SHIFT));
  80 }
  81 EXPORT_SYMBOL(__arm_ioremap_pfn);
  82
  83 void __iomem *__arm_ioremap_pfn_caller(unsigned long pfn, unsigned long offset,
  84                            size_t size, unsigned int mtype, void *caller)
  85 {
  86         return __arm_ioremap_pfn(pfn, offset, size, mtype);
  87 }
  88
  89 void __iomem *__arm_ioremap(unsigned long phys_addr, size_t size,
  90                             unsigned int mtype)
  91 {
  92         return (void __iomem *)phys_addr;
  93 }
  94 EXPORT_SYMBOL(__arm_ioremap);
  95
  96 void __iomem *__arm_ioremap_caller(unsigned long phys_addr, size_t size,
  97                                    unsigned int mtype, void *caller)
  98 {
  99         return __arm_ioremap(phys_addr, size, mtype);
 100 }
 101
 102 void __iounmap(volatile void __iomem *addr)
 103 {
 104 }
 105 EXPORT_SYMBOL(__iounmap);