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/*
* Copyright (C) 2004-2006 Atmel Corporation
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/vmalloc.h>
#include <linux/module.h>
#include <asm/io.h>
#include <asm/pgtable.h>
#include <asm/cacheflush.h>
#include <asm/tlbflush.h>
#include <asm/addrspace.h>
static inline int remap_area_pte(pte_t *pte, unsigned long address,
unsigned long end, unsigned long phys_addr,
pgprot_t prot)
{
unsigned long pfn;
pfn = phys_addr >> PAGE_SHIFT;
do {
WARN_ON(!pte_none(*pte));
set_pte(pte, pfn_pte(pfn, prot));
address += PAGE_SIZE;
pfn++;
pte++;
} while (address && (address < end));
return 0;
}
static inline int remap_area_pmd(pmd_t *pmd, unsigned long address,
unsigned long end, unsigned long phys_addr,
pgprot_t prot)
{
unsigned long next;
phys_addr -= address;
do {
pte_t *pte = pte_alloc_kernel(pmd, address);
if (!pte)
return -ENOMEM;
next = (address + PMD_SIZE) & PMD_MASK;
if (remap_area_pte(pte, address, next,
address + phys_addr, prot))
return -ENOMEM;
address = next;
pmd++;
} while (address && (address < end));
return 0;
}
static int remap_area_pud(pud_t *pud, unsigned long address,
unsigned long end, unsigned long phys_addr,
pgprot_t prot)
{
unsigned long next;
phys_addr -= address;
do {
pmd_t *pmd = pmd_alloc(&init_mm, pud, address);
if (!pmd)
return -ENOMEM;
next = (address + PUD_SIZE) & PUD_MASK;
if (remap_area_pmd(pmd, address, next,
phys_addr + address, prot))
return -ENOMEM;
address = next;
pud++;
} while (address && address < end);
return 0;
}
static int remap_area_pages(unsigned long address, unsigned long phys_addr,
size_t size, pgprot_t prot)
{
unsigned long end = address + size;
unsigned long next;
pgd_t *pgd;
int err = 0;
phys_addr -= address;
pgd = pgd_offset_k(address);
flush_cache_all();
BUG_ON(address >= end);
spin_lock(&init_mm.page_table_lock);
do {
pud_t *pud = pud_alloc(&init_mm, pgd, address);
err = -ENOMEM;
if (!pud)
break;
next = (address + PGDIR_SIZE) & PGDIR_MASK;
if (next < address || next > end)
next = end;
err = remap_area_pud(pud, address, next,
phys_addr + address, prot);
if (err)
break;
address = next;
pgd++;
} while (address && (address < end));
spin_unlock(&init_mm.page_table_lock);
flush_tlb_all();
return err;
}
/*
* Re-map an arbitrary physical address space into the kernel virtual
* address space. Needed when the kernel wants to access physical
* memory directly.
*/
void __iomem *__ioremap(unsigned long phys_addr, size_t size,
unsigned long flags)
{
void *addr;
struct vm_struct *area;
unsigned long offset, last_addr;
pgprot_t prot;
/*
* Check if we can simply use the P4 segment. This area is
* uncacheable, so if caching/buffering is requested, we can't
* use it.
*/
if ((phys_addr >= P4SEG) && (flags == 0))
return (void __iomem *)phys_addr;
/* Don't allow wraparound or zero size */
last_addr = phys_addr + size - 1;
if (!size || last_addr < phys_addr)
return NULL;
/*
* XXX: When mapping regular RAM, we'd better make damn sure
* it's never used for anything else. But this is really the
* caller's responsibility...
*/
if (PHYSADDR(P2SEGADDR(phys_addr)) == phys_addr)
return (void __iomem *)P2SEGADDR(phys_addr);
/* Mappings have to be page-aligned */
offset = phys_addr & ~PAGE_MASK;
phys_addr &= PAGE_MASK;
size = PAGE_ALIGN(last_addr + 1) - phys_addr;
prot = __pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_DIRTY
| _PAGE_ACCESSED | _PAGE_TYPE_SMALL | flags);
/*
* Ok, go for it..
*/
area = get_vm_area(size, VM_IOREMAP);
if (!area)
return NULL;
area->phys_addr = phys_addr;
addr = area->addr;
if (remap_area_pages((unsigned long)addr, phys_addr, size, prot)) {
vunmap(addr);
return NULL;
}
return (void __iomem *)(offset + (char *)addr);
}
EXPORT_SYMBOL(__ioremap);
void __iounmap(void __iomem *addr)
{
struct vm_struct *p;
if ((unsigned long)addr >= P4SEG)
return;
p = remove_vm_area((void *)(PAGE_MASK & (unsigned long __force)addr));
if (unlikely(!p)) {
printk (KERN_ERR "iounmap: bad address %p\n", addr);
return;
}
kfree (p);
}
EXPORT_SYMBOL(__iounmap);
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