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/*
* Copyright (C) 2004-2006 Atmel Corporation
*
* 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.
*/
#include <linux/vmalloc.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/io.h>
#include <linux/slab.h>
#include <asm/pgtable.h>
#include <asm/addrspace.h>
/*
* Re-map an arbitrary physical address space into the kernel virtual
* address space. Needed when the kernel wants to access physical
* memory directly.
*/
void __iomem *__ioremap(unsigned long phys_addr, size_t size,
unsigned long flags)
{
unsigned long addr;
struct vm_struct *area;
unsigned long offset, last_addr;
pgprot_t prot;
/*
* Check if we can simply use the P4 segment. This area is
* uncacheable, so if caching/buffering is requested, we can't
* use it.
*/
if ((phys_addr >= P4SEG) && (flags == 0))
return (void __iomem *)phys_addr;
/* Don't allow wraparound or zero size */
last_addr = phys_addr + size - 1;
if (!size || last_addr < phys_addr)
return NULL;
/*
* XXX: When mapping regular RAM, we'd better make damn sure
* it's never used for anything else. But this is really the
* caller's responsibility...
*/
if (PHYSADDR(P2SEGADDR(phys_addr)) == phys_addr)
return (void __iomem *)P2SEGADDR(phys_addr);
/* Mappings have to be page-aligned */
offset = phys_addr & ~PAGE_MASK;
phys_addr &= PAGE_MASK;
size = PAGE_ALIGN(last_addr + 1) - phys_addr;
prot = __pgprot(_PAGE_PRESENT | _PAGE_GLOBAL | _PAGE_RW | _PAGE_DIRTY
| _PAGE_ACCESSED | _PAGE_TYPE_SMALL | flags);
/*
* Ok, go for it..
*/
area = get_vm_area(size, VM_IOREMAP);
if (!area)
return NULL;
area->phys_addr = phys_addr;
addr = (unsigned long )area->addr;
if (ioremap_page_range(addr, addr + size, phys_addr, prot)) {
vunmap((void *)addr);
return NULL;
}
return (void __iomem *)(offset + (char *)addr);
}
EXPORT_SYMBOL(__ioremap);
void __iounmap(void __iomem *addr)
{
struct vm_struct *p;
if ((unsigned long)addr >= P4SEG)
return;
if (PXSEG(addr) == P2SEG)
return;
p = remove_vm_area((void *)(PAGE_MASK & (unsigned long __force)addr));
if (unlikely(!p)) {
printk (KERN_ERR "iounmap: bad address %p\n", addr);
return;
}
kfree (p);
}
EXPORT_SYMBOL(__iounmap);
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