arch/nds32/mm/ioremap.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 // Copyright (C) 2005-2017 Andes Technology Corporation
   3
   4 #include <linux/vmalloc.h>
   5 #include <linux/io.h>
   6 #include <linux/mm.h>
   7 #include <asm/pgtable.h>
   8
   9 void __iomem *ioremap(phys_addr_t phys_addr, size_t size);
  10
  11 static void __iomem *__ioremap_caller(phys_addr_t phys_addr, size_t size,
  12                                       void *caller)
  13 {
  14         struct vm_struct *area;
  15         unsigned long addr, offset, last_addr;
  16         pgprot_t prot;
  17
  18         /* Don't allow wraparound or zero size */
  19         last_addr = phys_addr + size - 1;
  20         if (!size || last_addr < phys_addr)
  21                 return NULL;
  22
  23         /*
  24          * Mappings have to be page-aligned
  25          */
  26         offset = phys_addr & ~PAGE_MASK;
  27         phys_addr &= PAGE_MASK;
  28         size = PAGE_ALIGN(last_addr + 1) - phys_addr;
  29
  30         /*
  31          * Ok, go for it..
  32          */
  33         area = get_vm_area_caller(size, VM_IOREMAP, caller);
  34         if (!area)
  35                 return NULL;
  36
  37         area->phys_addr = phys_addr;
  38         addr = (unsigned long)area->addr;
  39         prot = __pgprot(_PAGE_V | _PAGE_M_KRW | _PAGE_D |
  40                         _PAGE_G | _PAGE_C_DEV);
  41         if (ioremap_page_range(addr, addr + size, phys_addr, prot)) {
  42                 vunmap((void *)addr);
  43                 return NULL;
  44         }
  45         return (__force void __iomem *)(offset + (char *)addr);
  46
  47 }
  48
  49 void __iomem *ioremap(phys_addr_t phys_addr, size_t size)
  50 {
  51         return __ioremap_caller(phys_addr, size,
  52                                 __builtin_return_address(0));
  53 }
  54
  55 EXPORT_SYMBOL(ioremap);
  56
  57 void iounmap(volatile void __iomem * addr)
  58 {
  59         vunmap((void *)(PAGE_MASK & (unsigned long)addr));
  60 }
  61
  62 EXPORT_SYMBOL(iounmap);