linux/arch/sh/mm/ioremap_fixed.c

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/*
* Re-map IO memory to kernel address space so that we can access it.
*
* These functions should only be used when it is necessary to map a
* physical address space into the kernel address space before ioremap()
* can be used, e.g. early in boot before paging_init().
*
* Copyright (C) 2009 Matt Fleming
*/
#include <linux/vmalloc.h>
#include <linux/ioport.h>
#include <linux/module.h>
#include <linux/mm.h>
#include <linux/io.h>
#include <linux/bootmem.h>
#include <linux/proc_fs.h>
#include <asm/fixmap.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>
#include <asm/mmu_context.h>
struct ioremap_map {
void __iomem *addr;
unsigned long size;
unsigned long fixmap_addr;
};
static struct ioremap_map ioremap_maps[FIX_N_IOREMAPS];
void __init ioremap_fixed_init(void)
{
struct ioremap_map *map;
int i;
for (i = 0; i < FIX_N_IOREMAPS; i++) {
map = &ioremap_maps[i];
map->fixmap_addr = __fix_to_virt(FIX_IOREMAP_BEGIN + i);
}
}
void __init __iomem *
ioremap_fixed(phys_addr_t phys_addr, unsigned long size, pgprot_t prot)
{
enum fixed_addresses idx0, idx;
struct ioremap_map *map;
unsigned int nrpages;
unsigned long offset;
int i, slot;
/*
* Mappings have to be page-aligned
*/
offset = phys_addr & ~PAGE_MASK;
phys_addr &= PAGE_MASK;
size = PAGE_ALIGN(phys_addr + size) - phys_addr;
slot = -1;
for (i = 0; i < FIX_N_IOREMAPS; i++) {
map = &ioremap_maps[i];
if (!map->addr) {
map->size = size;
slot = i;
break;
}
}
if (slot < 0)
return NULL;
/*
* Mappings have to fit in the FIX_IOREMAP area.
*/
nrpages = size >> PAGE_SHIFT;
if (nrpages > FIX_N_IOREMAPS)
return NULL;
/*
* Ok, go for it..
*/
idx0 = FIX_IOREMAP_BEGIN + slot;
idx = idx0;
while (nrpages > 0) {
pgprot_val(prot) |= _PAGE_WIRED;
__set_fixmap(idx, phys_addr, prot);
phys_addr += PAGE_SIZE;
idx++;
--nrpages;
}
map->addr = (void __iomem *)(offset + map->fixmap_addr);
return map->addr;
}
int iounmap_fixed(void __iomem *addr)
{
enum fixed_addresses idx;
struct ioremap_map *map;
unsigned int nrpages;
int i, slot;
slot = -1;
for (i = 0; i < FIX_N_IOREMAPS; i++) {
map = &ioremap_maps[i];
if (map->addr == addr) {
slot = i;
break;
}
}
/*
* If we don't match, it's not for us.
*/
if (slot < 0)
return -EINVAL;
nrpages = map->size >> PAGE_SHIFT;
idx = FIX_IOREMAP_BEGIN + slot + nrpages - 1;
while (nrpages > 0) {
__clear_fixmap(idx, __pgprot(_PAGE_WIRED));
--idx;
--nrpages;
}
map->size = 0;
map->addr = NULL;
return 0;
}