mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson
synced 2025-10-31 00:01:35 +00:00
100 lines
2.4 KiB
C
100 lines
2.4 KiB
C
/*
|
|
* 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) - 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);
|