61e85e3675
Signed-off-by: Jonas Bonn <jonas@southpole.se> Reviewed-by: Arnd Bergmann <arnd@arndb.de>
137 lines
3.8 KiB
C
137 lines
3.8 KiB
C
/*
|
|
* OpenRISC ioremap.c
|
|
*
|
|
* Linux architectural port borrowing liberally from similar works of
|
|
* others. All original copyrights apply as per the original source
|
|
* declaration.
|
|
*
|
|
* Modifications for the OpenRISC architecture:
|
|
* Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
|
|
* Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public License
|
|
* as published by the Free Software Foundation; either version
|
|
* 2 of the License, or (at your option) any later version.
|
|
*/
|
|
|
|
#include <linux/vmalloc.h>
|
|
#include <linux/io.h>
|
|
#include <asm/pgalloc.h>
|
|
#include <asm/kmap_types.h>
|
|
#include <asm/fixmap.h>
|
|
#include <asm/bug.h>
|
|
#include <asm/pgtable.h>
|
|
#include <linux/sched.h>
|
|
#include <asm/tlbflush.h>
|
|
|
|
extern int mem_init_done;
|
|
|
|
static unsigned int fixmaps_used __initdata;
|
|
|
|
/*
|
|
* 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 *__init_refok
|
|
__ioremap(phys_addr_t addr, unsigned long size, pgprot_t prot)
|
|
{
|
|
phys_addr_t p;
|
|
unsigned long v;
|
|
unsigned long offset, last_addr;
|
|
struct vm_struct *area = NULL;
|
|
|
|
/* Don't allow wraparound or zero size */
|
|
last_addr = addr + size - 1;
|
|
if (!size || last_addr < addr)
|
|
return NULL;
|
|
|
|
/*
|
|
* Mappings have to be page-aligned
|
|
*/
|
|
offset = addr & ~PAGE_MASK;
|
|
p = addr & PAGE_MASK;
|
|
size = PAGE_ALIGN(last_addr + 1) - p;
|
|
|
|
if (likely(mem_init_done)) {
|
|
area = get_vm_area(size, VM_IOREMAP);
|
|
if (!area)
|
|
return NULL;
|
|
v = (unsigned long)area->addr;
|
|
} else {
|
|
if ((fixmaps_used + (size >> PAGE_SHIFT)) > FIX_N_IOREMAPS)
|
|
return NULL;
|
|
v = fix_to_virt(FIX_IOREMAP_BEGIN + fixmaps_used);
|
|
fixmaps_used += (size >> PAGE_SHIFT);
|
|
}
|
|
|
|
if (ioremap_page_range(v, v + size, p, prot)) {
|
|
if (likely(mem_init_done))
|
|
vfree(area->addr);
|
|
else
|
|
fixmaps_used -= (size >> PAGE_SHIFT);
|
|
return NULL;
|
|
}
|
|
|
|
return (void __iomem *)(offset + (char *)v);
|
|
}
|
|
|
|
void iounmap(void *addr)
|
|
{
|
|
/* If the page is from the fixmap pool then we just clear out
|
|
* the fixmap mapping.
|
|
*/
|
|
if (unlikely((unsigned long)addr > FIXADDR_START)) {
|
|
/* This is a bit broken... we don't really know
|
|
* how big the area is so it's difficult to know
|
|
* how many fixed pages to invalidate...
|
|
* just flush tlb and hope for the best...
|
|
* consider this a FIXME
|
|
*
|
|
* Really we should be clearing out one or more page
|
|
* table entries for these virtual addresses so that
|
|
* future references cause a page fault... for now, we
|
|
* rely on two things:
|
|
* i) this code never gets called on known boards
|
|
* ii) invalid accesses to the freed areas aren't made
|
|
*/
|
|
flush_tlb_all();
|
|
return;
|
|
}
|
|
|
|
return vfree((void *)(PAGE_MASK & (unsigned long)addr));
|
|
}
|
|
|
|
/**
|
|
* OK, this one's a bit tricky... ioremap can get called before memory is
|
|
* initialized (early serial console does this) and will want to alloc a page
|
|
* for its mapping. No userspace pages will ever get allocated before memory
|
|
* is initialized so this applies only to kernel pages. In the event that
|
|
* this is called before memory is initialized we allocate the page using
|
|
* the memblock infrastructure.
|
|
*/
|
|
|
|
pte_t __init_refok *pte_alloc_one_kernel(struct mm_struct *mm,
|
|
unsigned long address)
|
|
{
|
|
pte_t *pte;
|
|
|
|
if (likely(mem_init_done)) {
|
|
pte = (pte_t *) __get_free_page(GFP_KERNEL | __GFP_REPEAT);
|
|
} else {
|
|
pte = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE);
|
|
#if 0
|
|
/* FIXME: use memblock... */
|
|
pte = (pte_t *) __va(memblock_alloc(PAGE_SIZE, PAGE_SIZE));
|
|
#endif
|
|
}
|
|
|
|
if (pte)
|
|
clear_page(pte);
|
|
return pte;
|
|
}
|