/*
* 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 <asm/io.h>
#include <asm/page.h>
#include <asm/pgalloc.h>
#include <asm/addrspace.h>
#include <asm/cacheflush.h>
#include <asm/tlbflush.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;
unsigned long pfn;
pgprot_t pgprot = __pgprot(_PAGE_PRESENT | _PAGE_RW |
_PAGE_DIRTY | _PAGE_ACCESSED |
_PAGE_HW_SHARED | _PAGE_FLAGS_HARD | 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,
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;
phys_addr -= address;
if (address >= end)
BUG();
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;
}
int remap_area_pages(unsigned long address, unsigned long phys_addr,
unsigned long size, unsigned long flags)
{
int error;
pgd_t * dir;
unsigned long end = address + size;
phys_addr -= address;
dir = pgd_offset_k(address);
flush_cache_all();
if (address >= end)
BUG();
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;
}
/*
* 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;
/* Don't allow wraparound or zero size */
last_addr = phys_addr + size - 1;
if (!size || last_addr < phys_addr)
return NULL;
/*
* Don't remap the low PCI/ISA area, it's always mapped..
*/
if (phys_addr >= 0xA0000 && last_addr < 0x100000)
return (void __iomem *)phys_to_virt(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
if (likely(size))
if (remap_area_pages(addr, phys_addr, size, flags)) {
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)
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);
