linux-sg2042/arch/parisc/mm/ioremap.c

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/*
* arch/parisc/mm/ioremap.c
*
* (C) Copyright 1995 1996 Linus Torvalds
* (C) Copyright 2001-2006 Helge Deller <deller@gmx.de>
* (C) Copyright 2005 Kyle McMartin <kyle@parisc-linux.org>
*/
#include <linux/vmalloc.h>
#include <linux/errno.h>
#include <linux/module.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.
*
* 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.
*/
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;
#ifdef CONFIG_EISA
unsigned long end = phys_addr + size - 1;
/* Support EISA addresses */
if ((phys_addr >= 0x00080000 && end < 0x000fffff) ||
(phys_addr >= 0x00500000 && end < 0x03bfffff)) {
phys_addr |= F_EXTEND(0xfc000000);
flags |= _PAGE_NO_CACHE;
}
#endif
/* Don't allow wraparound or zero size */
last_addr = phys_addr + size - 1;
if (!size || last_addr < phys_addr)
return NULL;
/*
* 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_PRESENT | _PAGE_RW | _PAGE_DIRTY |
_PAGE_ACCESSED | 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;
addr = (void __iomem *) area->addr;
if (ioremap_page_range((unsigned long)addr, (unsigned long)addr + size,
phys_addr, pgprot)) {
vfree(addr);
return NULL;
}
return (void __iomem *) (offset + (char __iomem *)addr);
}
EXPORT_SYMBOL(__ioremap);
void iounmap(const volatile void __iomem *addr)
{
if (addr > high_memory)
return vfree((void *) (PAGE_MASK & (unsigned long __force) addr));
}
EXPORT_SYMBOL(iounmap);