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kernel add
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/*
* linux/arch/m32r/mm/ioremap.c
*
* Copyright (c) 2001, 2002 Hiroyuki Kondo
*
* Taken from mips version.
* (C) Copyright 1995 1996 Linus Torvalds
* (C) Copyright 2001 Ralf Baechle
*/
/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
*/
#include <linux/module.h>
#include <asm/addrspace.h>
#include <asm/byteorder.h>
#include <linux/vmalloc.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.
*
* NOTE! We need to allow non-page-aligned mappings too: we will obviously
* have to convert them into an offset in a page-aligned mapping, but the
* caller shouldn't need to know that small detail.
*/
#define IS_LOW512(addr) (!((unsigned long)(addr) & ~0x1fffffffUL))
void __iomem *
__ioremap(unsigned long phys_addr, unsigned long size, unsigned long flags)
{
void __iomem * addr;
struct vm_struct * area;
unsigned long offset, last_addr;
pgprot_t pgprot;
/* Don't allow wraparound or zero size */
last_addr = phys_addr + size - 1;
if (!size || last_addr < phys_addr)
return NULL;
/*
* Map objects in the low 512mb of address space using KSEG1, otherwise
* map using page tables.
*/
if (IS_LOW512(phys_addr) && IS_LOW512(phys_addr + size - 1))
return (void *) KSEG1ADDR(phys_addr);
/*
* Don't allow anybody to remap normal RAM that we're using..
*/
if (phys_addr < virt_to_phys(high_memory)) {
char *t_addr, *t_end;
struct page *page;
t_addr = __va(phys_addr);
t_end = t_addr + (size - 1);
for(page = virt_to_page(t_addr); page <= virt_to_page(t_end); page++)
if(!PageReserved(page))
return NULL;
}
pgprot = __pgprot(_PAGE_GLOBAL | _PAGE_PRESENT | _PAGE_READ
| _PAGE_WRITE | flags);
/*
* Mappings have to be page-aligned
*/
offset = phys_addr & ~PAGE_MASK;
phys_addr &= PAGE_MASK;
size = PAGE_ALIGN(last_addr + 1) - phys_addr;
/*
* Ok, go for it..
*/
area = get_vm_area(size, VM_IOREMAP);
if (!area)
return NULL;
area->phys_addr = phys_addr;
addr = (void __iomem *) area->addr;
if (ioremap_page_range((unsigned long)addr, (unsigned long)addr + size,
phys_addr, pgprot)) {
vunmap((void __force *) addr);
return NULL;
}
return (void __iomem *) (offset + (char __iomem *)addr);
}
#define IS_KSEG1(addr) (((unsigned long)(addr) & ~0x1fffffffUL) == KSEG1)
void iounmap(volatile void __iomem *addr)
{
if (!IS_KSEG1(addr))
vfree((void *) (PAGE_MASK & (unsigned long) addr));
}
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