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/*
* arch/sh/mm/ioremap.c
*
* 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
*
* (C) Copyright 1995 1996 Linus Torvalds
* (C) Copyright 2005, 2006 Paul Mundt
*
* 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/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 *__ioremap(unsigned long phys_addr, unsigned long size,
unsigned long flags)
{
struct vm_struct * area;
unsigned long offset, last_addr, addr, orig_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;
/*
* If we're on an SH7751 or SH7780 PCI controller, PCI memory is
* mapped at the end of the address space (typically 0xfd000000)
* in a non-translatable area, so mapping through page tables for
* this area is not only pointless, but also fundamentally
* broken. Just return the physical address instead.
*
* For boards that map a small PCI memory aperture somewhere in
* P1/P2 space, ioremap() will already do the right thing,
* and we'll never get this far.
*/
if (is_pci_memaddr(phys_addr) && is_pci_memaddr(last_addr))
return (void __iomem *)phys_addr;
/*
* Don't allow anybody to remap normal RAM that we're using..
*/
if (phys_addr < virt_to_phys(high_memory))
return NULL;
/*
* 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;
orig_addr = addr = (unsigned long)area->addr;
#ifdef CONFIG_32BIT
/*
* First try to remap through the PMB once a valid VMA has been
* established. Smaller allocations (or the rest of the size
* remaining after a PMB mapping due to the size not being
* perfectly aligned on a PMB size boundary) are then mapped
* through the UTLB using conventional page tables.
*
* PMB entries are all pre-faulted.
*/
if (unlikely(size >= 0x1000000)) {
unsigned long mapped = pmb_remap(addr, phys_addr, size, flags);
if (likely(mapped)) {
addr += mapped;
phys_addr += mapped;
size -= mapped;
}
}
#endif
pgprot = __pgprot(pgprot_val(PAGE_KERNEL_NOCACHE) | flags);
if (likely(size))
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);
void __iounmap(void __iomem *addr)
{
unsigned long vaddr = (unsigned long __force)addr;
struct vm_struct *p;
if (PXSEG(vaddr) < P3SEG || is_pci_memaddr(vaddr))
return;
#ifdef CONFIG_32BIT
/*
* Purge any PMB entries that may have been established for this
* mapping, then proceed with conventional VMA teardown.
*
* XXX: Note that due to the way that remove_vm_area() does
* matching of the resultant VMA, we aren't able to fast-forward
* the address past the PMB space until the end of the VMA where
* the page tables reside. As such, unmap_vm_area() will be
* forced to linearly scan over the area until it finds the page
* tables where PTEs that need to be unmapped actually reside,
* which is far from optimal. Perhaps we need to use a separate
* VMA for the PMB mappings?
* -- PFM.
*/
pmb_unmap(vaddr);
#endif
p = remove_vm_area((void *)(vaddr & PAGE_MASK));
if (!p) {
printk(KERN_ERR "%s: bad address %p\n", __FUNCTION__, addr);
return;
}
kfree(p);
}
EXPORT_SYMBOL(__iounmap);
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