kernel-ark/arch/powerpc/mm/pgtable_64.c
Benjamin Herrenschmidt a32525449b [POWERPC] Fix bug with early ioremap and 64k pages
The code for bolting hash entries for ioremap done before proper
mm initialization has a grown a bug when using 64K pages on a
machine where non-cacheable mappings are demoted to 4K HW pages.
The wrong page size index is being passed to the hash table mapping
functions causing a crash at boot on some pSeries machines using
bare metal linux.  This fixes it.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-02-16 14:00:20 +11:00

337 lines
8.0 KiB
C

/*
* This file contains ioremap and related functions for 64-bit machines.
*
* Derived from arch/ppc64/mm/init.c
* Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
*
* Modifications by Paul Mackerras (PowerMac) (paulus@samba.org)
* and Cort Dougan (PReP) (cort@cs.nmt.edu)
* Copyright (C) 1996 Paul Mackerras
* Amiga/APUS changes by Jesper Skov (jskov@cygnus.co.uk).
*
* Derived from "arch/i386/mm/init.c"
* Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
*
* Dave Engebretsen <engebret@us.ibm.com>
* Rework for PPC64 port.
*
* 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/signal.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/types.h>
#include <linux/mman.h>
#include <linux/mm.h>
#include <linux/swap.h>
#include <linux/stddef.h>
#include <linux/vmalloc.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/bootmem.h>
#include <linux/highmem.h>
#include <linux/idr.h>
#include <linux/nodemask.h>
#include <linux/module.h>
#include <asm/pgalloc.h>
#include <asm/page.h>
#include <asm/prom.h>
#include <asm/lmb.h>
#include <asm/rtas.h>
#include <asm/io.h>
#include <asm/mmu_context.h>
#include <asm/pgtable.h>
#include <asm/mmu.h>
#include <asm/uaccess.h>
#include <asm/smp.h>
#include <asm/machdep.h>
#include <asm/tlb.h>
#include <asm/eeh.h>
#include <asm/processor.h>
#include <asm/mmzone.h>
#include <asm/cputable.h>
#include <asm/sections.h>
#include <asm/system.h>
#include <asm/iommu.h>
#include <asm/abs_addr.h>
#include <asm/vdso.h>
#include <asm/firmware.h>
#include "mmu_decl.h"
unsigned long ioremap_bot = IMALLOC_BASE;
static unsigned long phbs_io_bot = PHBS_IO_BASE;
/*
* map_io_page currently only called by __ioremap
* map_io_page adds an entry to the ioremap page table
* and adds an entry to the HPT, possibly bolting it
*/
static int map_io_page(unsigned long ea, unsigned long pa, int flags)
{
pgd_t *pgdp;
pud_t *pudp;
pmd_t *pmdp;
pte_t *ptep;
if (mem_init_done) {
pgdp = pgd_offset_k(ea);
pudp = pud_alloc(&init_mm, pgdp, ea);
if (!pudp)
return -ENOMEM;
pmdp = pmd_alloc(&init_mm, pudp, ea);
if (!pmdp)
return -ENOMEM;
ptep = pte_alloc_kernel(pmdp, ea);
if (!ptep)
return -ENOMEM;
set_pte_at(&init_mm, ea, ptep, pfn_pte(pa >> PAGE_SHIFT,
__pgprot(flags)));
} else {
/*
* If the mm subsystem is not fully up, we cannot create a
* linux page table entry for this mapping. Simply bolt an
* entry in the hardware page table.
*
*/
if (htab_bolt_mapping(ea, ea + PAGE_SIZE, pa, flags,
mmu_io_psize)) {
printk(KERN_ERR "Failed to do bolted mapping IO "
"memory at %016lx !\n", pa);
return -ENOMEM;
}
}
return 0;
}
static void __iomem * __ioremap_com(phys_addr_t addr, unsigned long pa,
unsigned long ea, unsigned long size,
unsigned long flags)
{
unsigned long i;
if ((flags & _PAGE_PRESENT) == 0)
flags |= pgprot_val(PAGE_KERNEL);
for (i = 0; i < size; i += PAGE_SIZE)
if (map_io_page(ea+i, pa+i, flags))
return NULL;
return (void __iomem *) (ea + (addr & ~PAGE_MASK));
}
void __iomem * __ioremap(phys_addr_t addr, unsigned long size,
unsigned long flags)
{
unsigned long pa, ea;
void __iomem *ret;
/*
* Choose an address to map it to.
* Once the imalloc system is running, we use it.
* Before that, we map using addresses going
* up from ioremap_bot. imalloc will use
* the addresses from ioremap_bot through
* IMALLOC_END
*
*/
pa = addr & PAGE_MASK;
size = PAGE_ALIGN(addr + size) - pa;
if ((size == 0) || (pa == 0))
return NULL;
if (mem_init_done) {
struct vm_struct *area;
area = im_get_free_area(size);
if (area == NULL)
return NULL;
ea = (unsigned long)(area->addr);
ret = __ioremap_com(addr, pa, ea, size, flags);
if (!ret)
im_free(area->addr);
} else {
ea = ioremap_bot;
ret = __ioremap_com(addr, pa, ea, size, flags);
if (ret)
ioremap_bot += size;
}
return ret;
}
void __iomem * ioremap(phys_addr_t addr, unsigned long size)
{
unsigned long flags = _PAGE_NO_CACHE | _PAGE_GUARDED;
if (ppc_md.ioremap)
return ppc_md.ioremap(addr, size, flags);
return __ioremap(addr, size, flags);
}
void __iomem * ioremap_flags(phys_addr_t addr, unsigned long size,
unsigned long flags)
{
if (ppc_md.ioremap)
return ppc_md.ioremap(addr, size, flags);
return __ioremap(addr, size, flags);
}
#define IS_PAGE_ALIGNED(_val) ((_val) == ((_val) & PAGE_MASK))
int __ioremap_explicit(phys_addr_t pa, unsigned long ea,
unsigned long size, unsigned long flags)
{
struct vm_struct *area;
void __iomem *ret;
/* For now, require page-aligned values for pa, ea, and size */
if (!IS_PAGE_ALIGNED(pa) || !IS_PAGE_ALIGNED(ea) ||
!IS_PAGE_ALIGNED(size)) {
printk(KERN_ERR "unaligned value in %s\n", __FUNCTION__);
return 1;
}
if (!mem_init_done) {
/* Two things to consider in this case:
* 1) No records will be kept (imalloc, etc) that the region
* has been remapped
* 2) It won't be easy to iounmap() the region later (because
* of 1)
*/
;
} else {
area = im_get_area(ea, size,
IM_REGION_UNUSED|IM_REGION_SUBSET|IM_REGION_EXISTS);
if (area == NULL) {
/* Expected when PHB-dlpar is in play */
return 1;
}
if (ea != (unsigned long) area->addr) {
printk(KERN_ERR "unexpected addr return from "
"im_get_area\n");
return 1;
}
}
ret = __ioremap_com(pa, pa, ea, size, flags);
if (ret == NULL) {
printk(KERN_ERR "ioremap_explicit() allocation failure !\n");
return 1;
}
if (ret != (void *) ea) {
printk(KERN_ERR "__ioremap_com() returned unexpected addr\n");
return 1;
}
return 0;
}
/*
* Unmap an IO region and remove it from imalloc'd list.
* Access to IO memory should be serialized by driver.
* This code is modeled after vmalloc code - unmap_vm_area()
*
* XXX what about calls before mem_init_done (ie python_countermeasures())
*/
void __iounmap(volatile void __iomem *token)
{
void *addr;
if (!mem_init_done)
return;
addr = (void *) ((unsigned long __force) token & PAGE_MASK);
im_free(addr);
}
void iounmap(volatile void __iomem *token)
{
if (ppc_md.iounmap)
ppc_md.iounmap(token);
else
__iounmap(token);
}
static int iounmap_subset_regions(unsigned long addr, unsigned long size)
{
struct vm_struct *area;
/* Check whether subsets of this region exist */
area = im_get_area(addr, size, IM_REGION_SUPERSET);
if (area == NULL)
return 1;
while (area) {
iounmap((void __iomem *) area->addr);
area = im_get_area(addr, size,
IM_REGION_SUPERSET);
}
return 0;
}
int __iounmap_explicit(volatile void __iomem *start, unsigned long size)
{
struct vm_struct *area;
unsigned long addr;
int rc;
addr = (unsigned long __force) start & PAGE_MASK;
/* Verify that the region either exists or is a subset of an existing
* region. In the latter case, split the parent region to create
* the exact region
*/
area = im_get_area(addr, size,
IM_REGION_EXISTS | IM_REGION_SUBSET);
if (area == NULL) {
/* Determine whether subset regions exist. If so, unmap */
rc = iounmap_subset_regions(addr, size);
if (rc) {
printk(KERN_ERR
"%s() cannot unmap nonexistent range 0x%lx\n",
__FUNCTION__, addr);
return 1;
}
} else {
iounmap((void __iomem *) area->addr);
}
/*
* FIXME! This can't be right:
iounmap(area->addr);
* Maybe it should be "iounmap(area);"
*/
return 0;
}
EXPORT_SYMBOL(ioremap);
EXPORT_SYMBOL(ioremap_flags);
EXPORT_SYMBOL(__ioremap);
EXPORT_SYMBOL(iounmap);
EXPORT_SYMBOL(__iounmap);
void __iomem * reserve_phb_iospace(unsigned long size)
{
void __iomem *virt_addr;
if (phbs_io_bot >= IMALLOC_BASE)
panic("reserve_phb_iospace(): phb io space overflow\n");
virt_addr = (void __iomem *) phbs_io_bot;
phbs_io_bot += size;
return virt_addr;
}