arch/hexagon/mm/ioremap.c

   1 /*
   2  * I/O remap functions for Hexagon
   3  *
   4  * Copyright (c) 2010-2011, The Linux Foundation. All rights reserved.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 and
   8  * only version 2 as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  18  * 02110-1301, USA.
  19  */
  20
  21 #include <linux/io.h>
  22 #include <linux/vmalloc.h>
  23 #include <linux/mm.h>
  24
  25 void __iomem *ioremap_nocache(unsigned long phys_addr, unsigned long size)
  26 {
  27         unsigned long last_addr, addr;
  28         unsigned long offset = phys_addr & ~PAGE_MASK;
  29         struct vm_struct *area;
  30
  31         pgprot_t prot = __pgprot(_PAGE_PRESENT|_PAGE_READ|_PAGE_WRITE
  32                                         |(__HEXAGON_C_DEV << 6));
  33
  34         last_addr = phys_addr + size - 1;
  35
  36         /*  Wrapping not allowed  */
  37         if (!size || (last_addr < phys_addr))
  38                 return NULL;
  39
  40         /*  Rounds up to next page size, including whole-page offset */
  41         size = PAGE_ALIGN(offset + size);
  42
  43         area = get_vm_area(size, VM_IOREMAP);
  44         addr = (unsigned long)area->addr;
  45
  46         if (ioremap_page_range(addr, addr+size, phys_addr, prot)) {
  47                 vunmap((void *)addr);
  48                 return NULL;
  49         }
  50
  51         return (void __iomem *) (offset + addr);
  52 }
  53
  54 void __iounmap(const volatile void __iomem *addr)
  55 {
  56         vunmap((void *) ((unsigned long) addr & PAGE_MASK));
  57 }