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kernel/linux-rt-4.4.41/arch/arm64/mm/ioremap.c 2.92 KB
5113f6f70   김현기   kernel add
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  /*
   * Based on arch/arm/mm/ioremap.c
   *
   * (C) Copyright 1995 1996 Linus Torvalds
   * Hacked for ARM by Phil Blundell <philb@gnu.org>
   * Hacked to allow all architectures to build, and various cleanups
   * by Russell King
   * Copyright (C) 2012 ARM Ltd.
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License version 2 as
   * published by the Free Software Foundation.
   *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program.  If not, see <http://www.gnu.org/licenses/>.
   */
  
  #include <linux/export.h>
  #include <linux/mm.h>
  #include <linux/vmalloc.h>
  #include <linux/io.h>
  
  #include <asm/fixmap.h>
  #include <asm/tlbflush.h>
  #include <asm/pgalloc.h>
  
  static void __iomem *__ioremap_caller(phys_addr_t phys_addr, size_t size,
  				      pgprot_t prot, void *caller)
  {
  	unsigned long last_addr;
  	unsigned long offset = phys_addr & ~PAGE_MASK;
  	int err;
  	unsigned long addr;
  	struct vm_struct *area;
  
  	/*
  	 * Page align the mapping address and size, taking account of any
  	 * offset.
  	 */
  	phys_addr &= PAGE_MASK;
  	size = PAGE_ALIGN(size + offset);
  
  	/*
  	 * Don't allow wraparound, zero size or outside PHYS_MASK.
  	 */
  	last_addr = phys_addr + size - 1;
  	if (!size || last_addr < phys_addr || (last_addr & ~PHYS_MASK))
  		return NULL;
  
  	/*
  	 * Don't allow RAM to be mapped.
  	 */
  	if (WARN_ON(pfn_valid(__phys_to_pfn(phys_addr))))
  		return NULL;
  
  	area = get_vm_area_caller(size, VM_IOREMAP, caller);
  	if (!area)
  		return NULL;
  	addr = (unsigned long)area->addr;
  	area->phys_addr = phys_addr;
  
  	err = ioremap_page_range(addr, addr + size, phys_addr, prot);
  	if (err) {
  		vunmap((void *)addr);
  		return NULL;
  	}
  
  	return (void __iomem *)(offset + addr);
  }
  
  void __iomem *__ioremap(phys_addr_t phys_addr, size_t size, pgprot_t prot)
  {
  	return __ioremap_caller(phys_addr, size, prot,
  				__builtin_return_address(0));
  }
  EXPORT_SYMBOL(__ioremap);
  
  void __iounmap(volatile void __iomem *io_addr)
  {
  	unsigned long addr = (unsigned long)io_addr & PAGE_MASK;
  
  	/*
  	 * We could get an address outside vmalloc range in case
  	 * of ioremap_cache() reusing a RAM mapping.
  	 */
  	if (VMALLOC_START <= addr && addr < VMALLOC_END)
  		vunmap((void *)addr);
  }
  EXPORT_SYMBOL(__iounmap);
  
  void __iomem *ioremap_cache(phys_addr_t phys_addr, size_t size)
  {
  	/* For normal memory we already have a cacheable mapping. */
  	if (pfn_valid(__phys_to_pfn(phys_addr)))
  		return (void __iomem *)__phys_to_virt(phys_addr);
  
  	return __ioremap_caller(phys_addr, size, __pgprot(PROT_NORMAL),
  				__builtin_return_address(0));
  }
  EXPORT_SYMBOL(ioremap_cache);
  
  /*
   * Must be called after early_fixmap_init
   */
  void __init early_ioremap_init(void)
  {
  	early_ioremap_setup();
  }