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/*
* arch/s390/mm/ioremap.c
*
* S390 version
* Copyright (C) 1999 IBM Deutschland Entwicklung GmbH, IBM Corporation
* Author(s): Hartmut Penner (hp@de.ibm.com)
*
* Derived from "arch/i386/mm/extable.c"
* (C) Copyright 1995 1996 Linus Torvalds
*
* Re-map IO memory to kernel address space so that we can access it.
* This is needed for high PCI addresses that aren't mapped in the
* 640k-1MB IO memory area on PC's
*/
#include <linux/vmalloc.h>
#include <linux/mm.h>
#include <linux/io.h>
#include <asm/pgalloc.h>
/*
* Generic mapping function (not visible outside):
*/
/*
* Remap an arbitrary physical address space into the kernel virtual
* address space. Needed when the kernel wants to access high addresses
* directly.
*/
void * __ioremap(unsigned long phys_addr, unsigned long size, unsigned long flags)
{
void * addr;
struct vm_struct * area;
if (phys_addr < virt_to_phys(high_memory))
return phys_to_virt(phys_addr);
if (phys_addr & ~PAGE_MASK)
return NULL;
size = PAGE_ALIGN(size);
if (!size || size > phys_addr + size)
return NULL;
area = get_vm_area(size, VM_IOREMAP);
if (!area)
return NULL;
addr = area->addr;
if (ioremap_page_range((unsigned long)addr, (unsigned long)addr + size,
phys_addr, __pgprot(flags))) {
vfree(addr);
return NULL;
}
return addr;
}
void iounmap(void *addr)
{
if (addr > high_memory)
vfree(addr);
}
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