a1fce73235
Allow peripherals before the start of RAM to be remapped. Signed-off-by: Stuart Menefy <stuart.menefy@st.com> Signed-off-by: Paul Mundt <lethal@linux-sh.org>
146 lines
4.0 KiB
C
146 lines
4.0 KiB
C
/*
|
|
* 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 <linux/pci.h>
|
|
#include <linux/io.h>
|
|
#include <asm/page.h>
|
|
#include <asm/pgalloc.h>
|
|
#include <asm/addrspace.h>
|
|
#include <asm/cacheflush.h>
|
|
#include <asm/tlbflush.h>
|
|
#include <asm/mmu.h>
|
|
|
|
/*
|
|
* 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;
|
|
pgprot_t pgprot;
|
|
|
|
/* Don't allow wraparound or zero size */
|
|
last_addr = phys_addr + size - 1;
|
|
if (!size || last_addr < phys_addr)
|
|
return NULL;
|
|
|
|
/*
|
|
* If we're in the fixed PCI memory range, mapping through page
|
|
* tables is not only pointless, but also fundamentally broken.
|
|
* Just return the physical address instead.
|
|
*
|
|
* For boards that map a small PCI memory aperture somewhere in
|
|
* P1/P2 space, ioremap() will already do the right thing,
|
|
* and we'll never get this far.
|
|
*/
|
|
if (is_pci_memory_fixed_range(phys_addr, size))
|
|
return (void __iomem *)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;
|
|
|
|
/*
|
|
* 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_PMB
|
|
/*
|
|
* 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
|
|
|
|
pgprot = __pgprot(pgprot_val(PAGE_KERNEL_NOCACHE) | flags);
|
|
if (likely(size))
|
|
if (ioremap_page_range(addr, addr + size, phys_addr, pgprot)) {
|
|
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;
|
|
unsigned long seg = PXSEG(vaddr);
|
|
struct vm_struct *p;
|
|
|
|
if (seg < P3SEG || vaddr >= P3_ADDR_MAX)
|
|
return;
|
|
if (is_pci_memory_fixed_range(vaddr, 0))
|
|
return;
|
|
|
|
#ifdef CONFIG_PMB
|
|
/*
|
|
* 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", __func__, addr);
|
|
return;
|
|
}
|
|
|
|
kfree(p);
|
|
}
|
|
EXPORT_SYMBOL(__iounmap);
|