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/*
* 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 <asm/io.h>
#include <asm/pgalloc.h>
#include <asm/tlbflush.h>
#include <asm/cacheflush.h>
static inline void
remap_area_pte(pte_t *pte, unsigned long address, unsigned long size,
unsigned long phys_addr, unsigned long flags)
{
unsigned long end, pfn;
pgprot_t pgprot = __pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_DIRTY |
_PAGE_ACCESSED | flags);
address &= ~PMD_MASK;
end = address + size;
if (end > PMD_SIZE)
end = PMD_SIZE;
BUG_ON(address >= end);
pfn = phys_addr >> PAGE_SHIFT;
do {
BUG_ON(!pte_none(*pte));
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, unsigned long size,
unsigned long phys_addr, unsigned long flags)
{
unsigned long end;
address &= ~PGDIR_MASK;
end = address + size;
if (end > PGDIR_SIZE)
end = PGDIR_SIZE;
BUG_ON(address >= end);
phys_addr -= address;
do {
pte_t *pte = pte_alloc_kernel(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, unsigned long phys_addr,
unsigned long size, unsigned long flags)
{
pgd_t *dir;
int error = 0;
unsigned long end = address + size;
BUG_ON(address >= end);
phys_addr -= address;
dir = pgd_offset_k(address);
flush_cache_all();
do {
pud_t *pud;
pmd_t *pmd;
error = -ENOMEM;
pud = pud_alloc(&init_mm, dir, address);
if (!pud)
break;
pmd = pmd_alloc(&init_mm, pud, address);
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));
flush_tlb_all();
return error;
}
/*
* 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;
#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;
}
}
/*
* 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 (remap_area_pages((unsigned long) addr, phys_addr, size, flags)) {
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);
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