326 lines
8.1 KiB
C
326 lines
8.1 KiB
C
/*
|
|
* arch/i386/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
|
|
*/
|
|
|
|
#include <linux/vmalloc.h>
|
|
#include <linux/init.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/module.h>
|
|
#include <asm/io.h>
|
|
#include <asm/fixmap.h>
|
|
#include <asm/cacheflush.h>
|
|
#include <asm/tlbflush.h>
|
|
#include <asm/pgtable.h>
|
|
|
|
#define ISA_START_ADDRESS 0xa0000
|
|
#define ISA_END_ADDRESS 0x100000
|
|
|
|
static int ioremap_pte_range(pmd_t *pmd, unsigned long addr,
|
|
unsigned long end, unsigned long phys_addr, unsigned long flags)
|
|
{
|
|
pte_t *pte;
|
|
unsigned long pfn;
|
|
|
|
pfn = phys_addr >> PAGE_SHIFT;
|
|
pte = pte_alloc_kernel(&init_mm, pmd, addr);
|
|
if (!pte)
|
|
return -ENOMEM;
|
|
do {
|
|
BUG_ON(!pte_none(*pte));
|
|
set_pte(pte, pfn_pte(pfn, __pgprot(_PAGE_PRESENT | _PAGE_RW |
|
|
_PAGE_DIRTY | _PAGE_ACCESSED | flags)));
|
|
pfn++;
|
|
} while (pte++, addr += PAGE_SIZE, addr != end);
|
|
return 0;
|
|
}
|
|
|
|
static inline int ioremap_pmd_range(pud_t *pud, unsigned long addr,
|
|
unsigned long end, unsigned long phys_addr, unsigned long flags)
|
|
{
|
|
pmd_t *pmd;
|
|
unsigned long next;
|
|
|
|
phys_addr -= addr;
|
|
pmd = pmd_alloc(&init_mm, pud, addr);
|
|
if (!pmd)
|
|
return -ENOMEM;
|
|
do {
|
|
next = pmd_addr_end(addr, end);
|
|
if (ioremap_pte_range(pmd, addr, next, phys_addr + addr, flags))
|
|
return -ENOMEM;
|
|
} while (pmd++, addr = next, addr != end);
|
|
return 0;
|
|
}
|
|
|
|
static inline int ioremap_pud_range(pgd_t *pgd, unsigned long addr,
|
|
unsigned long end, unsigned long phys_addr, unsigned long flags)
|
|
{
|
|
pud_t *pud;
|
|
unsigned long next;
|
|
|
|
phys_addr -= addr;
|
|
pud = pud_alloc(&init_mm, pgd, addr);
|
|
if (!pud)
|
|
return -ENOMEM;
|
|
do {
|
|
next = pud_addr_end(addr, end);
|
|
if (ioremap_pmd_range(pud, addr, next, phys_addr + addr, flags))
|
|
return -ENOMEM;
|
|
} while (pud++, addr = next, addr != end);
|
|
return 0;
|
|
}
|
|
|
|
static int ioremap_page_range(unsigned long addr,
|
|
unsigned long end, unsigned long phys_addr, unsigned long flags)
|
|
{
|
|
pgd_t *pgd;
|
|
unsigned long next;
|
|
int err;
|
|
|
|
BUG_ON(addr >= end);
|
|
flush_cache_all();
|
|
phys_addr -= addr;
|
|
pgd = pgd_offset_k(addr);
|
|
spin_lock(&init_mm.page_table_lock);
|
|
do {
|
|
next = pgd_addr_end(addr, end);
|
|
err = ioremap_pud_range(pgd, addr, next, phys_addr+addr, flags);
|
|
if (err)
|
|
break;
|
|
} while (pgd++, addr = next, addr != end);
|
|
spin_unlock(&init_mm.page_table_lock);
|
|
flush_tlb_all();
|
|
return err;
|
|
}
|
|
|
|
/*
|
|
* 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.
|
|
*/
|
|
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;
|
|
|
|
/* 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 >= ISA_START_ADDRESS && last_addr < ISA_END_ADDRESS)
|
|
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 - 1)) {
|
|
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 | (flags << 20));
|
|
if (!area)
|
|
return NULL;
|
|
area->phys_addr = phys_addr;
|
|
addr = (void __iomem *) area->addr;
|
|
if (ioremap_page_range((unsigned long) addr,
|
|
(unsigned long) addr + size, phys_addr, flags)) {
|
|
vunmap((void __force *) addr);
|
|
return NULL;
|
|
}
|
|
return (void __iomem *) (offset + (char __iomem *)addr);
|
|
}
|
|
EXPORT_SYMBOL(__ioremap);
|
|
|
|
/**
|
|
* ioremap_nocache - map bus memory into CPU space
|
|
* @offset: bus address of the memory
|
|
* @size: size of the resource to map
|
|
*
|
|
* ioremap_nocache performs a platform specific sequence of operations to
|
|
* make bus memory CPU accessible via the readb/readw/readl/writeb/
|
|
* writew/writel functions and the other mmio helpers. The returned
|
|
* address is not guaranteed to be usable directly as a virtual
|
|
* address.
|
|
*
|
|
* This version of ioremap ensures that the memory is marked uncachable
|
|
* on the CPU as well as honouring existing caching rules from things like
|
|
* the PCI bus. Note that there are other caches and buffers on many
|
|
* busses. In particular driver authors should read up on PCI writes
|
|
*
|
|
* It's useful if some control registers are in such an area and
|
|
* write combining or read caching is not desirable:
|
|
*
|
|
* Must be freed with iounmap.
|
|
*/
|
|
|
|
void __iomem *ioremap_nocache (unsigned long phys_addr, unsigned long size)
|
|
{
|
|
unsigned long last_addr;
|
|
void __iomem *p = __ioremap(phys_addr, size, _PAGE_PCD);
|
|
if (!p)
|
|
return p;
|
|
|
|
/* Guaranteed to be > phys_addr, as per __ioremap() */
|
|
last_addr = phys_addr + size - 1;
|
|
|
|
if (last_addr < virt_to_phys(high_memory) - 1) {
|
|
struct page *ppage = virt_to_page(__va(phys_addr));
|
|
unsigned long npages;
|
|
|
|
phys_addr &= PAGE_MASK;
|
|
|
|
/* This might overflow and become zero.. */
|
|
last_addr = PAGE_ALIGN(last_addr);
|
|
|
|
/* .. but that's ok, because modulo-2**n arithmetic will make
|
|
* the page-aligned "last - first" come out right.
|
|
*/
|
|
npages = (last_addr - phys_addr) >> PAGE_SHIFT;
|
|
|
|
if (change_page_attr(ppage, npages, PAGE_KERNEL_NOCACHE) < 0) {
|
|
iounmap(p);
|
|
p = NULL;
|
|
}
|
|
global_flush_tlb();
|
|
}
|
|
|
|
return p;
|
|
}
|
|
EXPORT_SYMBOL(ioremap_nocache);
|
|
|
|
void iounmap(volatile void __iomem *addr)
|
|
{
|
|
struct vm_struct *p;
|
|
if ((void __force *) addr <= high_memory)
|
|
return;
|
|
|
|
/*
|
|
* __ioremap special-cases the PCI/ISA range by not instantiating a
|
|
* vm_area and by simply returning an address into the kernel mapping
|
|
* of ISA space. So handle that here.
|
|
*/
|
|
if (addr >= phys_to_virt(ISA_START_ADDRESS) &&
|
|
addr < phys_to_virt(ISA_END_ADDRESS))
|
|
return;
|
|
|
|
write_lock(&vmlist_lock);
|
|
p = __remove_vm_area((void *) (PAGE_MASK & (unsigned long __force) addr));
|
|
if (!p) {
|
|
printk("iounmap: bad address %p\n", addr);
|
|
goto out_unlock;
|
|
}
|
|
|
|
if ((p->flags >> 20) && p->phys_addr < virt_to_phys(high_memory) - 1) {
|
|
change_page_attr(virt_to_page(__va(p->phys_addr)),
|
|
p->size >> PAGE_SHIFT,
|
|
PAGE_KERNEL);
|
|
global_flush_tlb();
|
|
}
|
|
out_unlock:
|
|
write_unlock(&vmlist_lock);
|
|
kfree(p);
|
|
}
|
|
EXPORT_SYMBOL(iounmap);
|
|
|
|
void __init *bt_ioremap(unsigned long phys_addr, unsigned long size)
|
|
{
|
|
unsigned long offset, last_addr;
|
|
unsigned int nrpages;
|
|
enum fixed_addresses idx;
|
|
|
|
/* 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 >= ISA_START_ADDRESS && last_addr < ISA_END_ADDRESS)
|
|
return phys_to_virt(phys_addr);
|
|
|
|
/*
|
|
* Mappings have to be page-aligned
|
|
*/
|
|
offset = phys_addr & ~PAGE_MASK;
|
|
phys_addr &= PAGE_MASK;
|
|
size = PAGE_ALIGN(last_addr) - phys_addr;
|
|
|
|
/*
|
|
* Mappings have to fit in the FIX_BTMAP area.
|
|
*/
|
|
nrpages = size >> PAGE_SHIFT;
|
|
if (nrpages > NR_FIX_BTMAPS)
|
|
return NULL;
|
|
|
|
/*
|
|
* Ok, go for it..
|
|
*/
|
|
idx = FIX_BTMAP_BEGIN;
|
|
while (nrpages > 0) {
|
|
set_fixmap(idx, phys_addr);
|
|
phys_addr += PAGE_SIZE;
|
|
--idx;
|
|
--nrpages;
|
|
}
|
|
return (void*) (offset + fix_to_virt(FIX_BTMAP_BEGIN));
|
|
}
|
|
|
|
void __init bt_iounmap(void *addr, unsigned long size)
|
|
{
|
|
unsigned long virt_addr;
|
|
unsigned long offset;
|
|
unsigned int nrpages;
|
|
enum fixed_addresses idx;
|
|
|
|
virt_addr = (unsigned long)addr;
|
|
if (virt_addr < fix_to_virt(FIX_BTMAP_BEGIN))
|
|
return;
|
|
offset = virt_addr & ~PAGE_MASK;
|
|
nrpages = PAGE_ALIGN(offset + size - 1) >> PAGE_SHIFT;
|
|
|
|
idx = FIX_BTMAP_BEGIN;
|
|
while (nrpages > 0) {
|
|
clear_fixmap(idx);
|
|
--idx;
|
|
--nrpages;
|
|
}
|
|
}
|