ioremap.c
3.22 KB
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/*
* arch/sh/mm/ioremap.c
*
* (C) Copyright 1995 1996 Linus Torvalds
* (C) Copyright 2005 - 2010 Paul Mundt
*
* 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
*
* 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/vmalloc.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/mm.h>
#include <linux/pci.h>
#include <linux/io.h>
#include <asm/page.h>
#include <asm/pgalloc.h>
#include <asm/addrspace.h>
#include <asm/cacheflush.h>
#include <asm/tlbflush.h>
#include <asm/mmu.h>
/*
* 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.
*/
void __iomem * __init_refok
__ioremap_caller(phys_addr_t phys_addr, unsigned long size,
pgprot_t pgprot, void *caller)
{
struct vm_struct *area;
unsigned long offset, last_addr, addr, orig_addr;
void __iomem *mapped;
/* Don't allow wraparound or zero size */
last_addr = phys_addr + size - 1;
if (!size || last_addr < phys_addr)
return NULL;
/*
* If we can't yet use the regular approach, go the fixmap route.
*/
if (!mem_init_done)
return ioremap_fixed(phys_addr, size, pgprot);
/*
* First try to remap through the PMB.
* PMB entries are all pre-faulted.
*/
mapped = pmb_remap_caller(phys_addr, size, pgprot, caller);
if (mapped && !IS_ERR(mapped))
return mapped;
/*
* 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_caller(size, VM_IOREMAP, caller);
if (!area)
return NULL;
area->phys_addr = phys_addr;
orig_addr = addr = (unsigned long)area->addr;
if (ioremap_page_range(addr, addr + size, phys_addr, pgprot)) {
vunmap((void *)orig_addr);
return NULL;
}
return (void __iomem *)(offset + (char *)orig_addr);
}
EXPORT_SYMBOL(__ioremap_caller);
/*
* Simple checks for non-translatable mappings.
*/
static inline int iomapping_nontranslatable(unsigned long offset)
{
#ifdef CONFIG_29BIT
/*
* In 29-bit mode this includes the fixed P1/P2 areas, as well as
* parts of P3.
*/
if (PXSEG(offset) < P3SEG || offset >= P3_ADDR_MAX)
return 1;
#endif
return 0;
}
void __iounmap(void __iomem *addr)
{
unsigned long vaddr = (unsigned long __force)addr;
struct vm_struct *p;
/*
* Nothing to do if there is no translatable mapping.
*/
if (iomapping_nontranslatable(vaddr))
return;
/*
* There's no VMA if it's from an early fixed mapping.
*/
if (iounmap_fixed(addr) == 0)
return;
/*
* If the PMB handled it, there's nothing else to do.
*/
if (pmb_unmap(addr) == 0)
return;
p = remove_vm_area((void *)(vaddr & PAGE_MASK));
if (!p) {
printk(KERN_ERR "%s: bad address %p\n", __func__, addr);
return;
}
kfree(p);
}
EXPORT_SYMBOL(__iounmap);