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/*
* 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.
*
* (C) Copyright 1995 1996 Linus Torvalds
* (C) Copyright 2001, 2002 Ralf Baechle
*/
#include <linux/module.h>
#include <asm/addrspace.h>
#include <asm/byteorder.h>
#include <linux/vmalloc.h>
#include <asm/cacheflush.h>
#include <asm/io.h>
#include <asm/tlbflush.h>
static inline void remap_area_pte(pte_t * pte, unsigned long address,
phys_t size, phys_t phys_addr, unsigned long flags)
{
phys_t end;
unsigned long pfn;
pgprot_t pgprot = __pgprot(_PAGE_GLOBAL | _PAGE_PRESENT | __READABLE
| __WRITEABLE | flags);
address &= ~PMD_MASK;
end = address + size;
if (end > PMD_SIZE)
end = PMD_SIZE;
if (address >= end)
BUG();
pfn = phys_addr >> PAGE_SHIFT;
do {
if (!pte_none(*pte)) {
printk("remap_area_pte: page already exists\n");
BUG();
}
set_pte(pte, pfn_pte(pfn, pgprot));
address += PAGE_SIZE;
pfn++;
pte++;
} while (address && (address < end));
}
static inline int remap_area_pmd(pmd_t * pmd, unsigned long address,
phys_t size, phys_t phys_addr, unsigned long flags)
{
phys_t end;
address &= ~PGDIR_MASK;
end = address + size;
if (end > PGDIR_SIZE)
end = PGDIR_SIZE;
phys_addr -= address;
if (address >= end)
BUG();
do {
pte_t * pte = pte_alloc_kernel(&init_mm, pmd, address);
if (!pte)
return -ENOMEM;
remap_area_pte(pte, address, end - address, address + phys_addr, flags);
address = (address + PMD_SIZE) & PMD_MASK;
pmd++;
} while (address && (address < end));
return 0;
}
static int remap_area_pages(unsigned long address, phys_t phys_addr,
phys_t size, unsigned long flags)
{
int error;
pgd_t * dir;
unsigned long end = address + size;
phys_addr -= address;
dir = pgd_offset(&init_mm, address);
flush_cache_all();
if (address >= end)
BUG();
spin_lock(&init_mm.page_table_lock);
do {
pmd_t *pmd;
pmd = pmd_alloc(&init_mm, dir, address);
error = -ENOMEM;
if (!pmd)
break;
if (remap_area_pmd(pmd, address, end - address,
phys_addr + address, flags))
break;
error = 0;
address = (address + PGDIR_SIZE) & PGDIR_MASK;
dir++;
} while (address && (address < end));
spin_unlock(&init_mm.page_table_lock);
flush_tlb_all();
return error;
}
/*
* Allow physical addresses to be fixed up to help 36 bit peripherals.
*/
phys_t __attribute__ ((weak))
fixup_bigphys_addr(phys_t phys_addr, phys_t size)
{
return phys_addr;
}
/*
* Generic mapping function (not visible outside):
*/
/*
* 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.
*/
#define IS_LOW512(addr) (!((phys_t)(addr) & (phys_t) ~0x1fffffffULL))
void * __ioremap(phys_t phys_addr, phys_t size, unsigned long flags)
{
struct vm_struct * area;
unsigned long offset;
phys_t last_addr;
void * addr;
phys_addr = fixup_bigphys_addr(phys_addr, size);
/* Don't allow wraparound or zero size */
last_addr = phys_addr + size - 1;
if (!size || last_addr < phys_addr)
return NULL;
/*
* Map uncached objects in the low 512mb of address space using KSEG1,
* otherwise map using page tables.
*/
if (IS_LOW512(phys_addr) && IS_LOW512(last_addr) &&
flags == _CACHE_UNCACHED)
return (void *) KSEG1ADDR(phys_addr);
/*
* 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;
}
/*
* 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 = area->addr;
if (remap_area_pages((unsigned long) addr, phys_addr, size, flags)) {
vunmap(addr);
return NULL;
}
return (void *) (offset + (char *)addr);
}
#define IS_KSEG1(addr) (((unsigned long)(addr) & ~0x1fffffffUL) == KSEG1)
void __iounmap(volatile void __iomem *addr)
{
struct vm_struct *p;
if (IS_KSEG1(addr))
return;
p = remove_vm_area((void *) (PAGE_MASK & (unsigned long __force) addr));
if (!p) {
printk(KERN_ERR "iounmap: bad address %p\n", addr);
return;
}
kfree(p);
}
EXPORT_SYMBOL(__ioremap);
EXPORT_SYMBOL(__iounmap);
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