287 lines
6.8 KiB
C
287 lines
6.8 KiB
C
/*
|
|
* This file contains the routines setting up the linux page tables.
|
|
*
|
|
* Copyright (C) 2008 Michal Simek
|
|
* Copyright (C) 2008 PetaLogix
|
|
*
|
|
* Copyright (C) 2007 Xilinx, Inc. All rights reserved.
|
|
*
|
|
* Derived from arch/ppc/mm/pgtable.c:
|
|
* -- paulus
|
|
*
|
|
* Derived from arch/ppc/mm/init.c:
|
|
* Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
|
|
*
|
|
* Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au)
|
|
* 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
|
|
*
|
|
* 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/kernel.h>
|
|
#include <linux/module.h>
|
|
#include <linux/types.h>
|
|
#include <linux/vmalloc.h>
|
|
#include <linux/init.h>
|
|
|
|
#include <asm/pgtable.h>
|
|
#include <asm/pgalloc.h>
|
|
#include <linux/io.h>
|
|
#include <asm/mmu.h>
|
|
#include <asm/sections.h>
|
|
|
|
#define flush_HPTE(X, va, pg) _tlbie(va)
|
|
|
|
unsigned long ioremap_base;
|
|
unsigned long ioremap_bot;
|
|
|
|
/* The maximum lowmem defaults to 768Mb, but this can be configured to
|
|
* another value.
|
|
*/
|
|
#define MAX_LOW_MEM CONFIG_LOWMEM_SIZE
|
|
|
|
#ifndef CONFIG_SMP
|
|
struct pgtable_cache_struct quicklists;
|
|
#endif
|
|
|
|
static void __iomem *__ioremap(phys_addr_t addr, unsigned long size,
|
|
unsigned long flags)
|
|
{
|
|
unsigned long v, i;
|
|
phys_addr_t p;
|
|
int err;
|
|
|
|
/*
|
|
* Choose an address to map it to.
|
|
* Once the vmalloc system is running, we use it.
|
|
* Before then, we use space going down from ioremap_base
|
|
* (ioremap_bot records where we're up to).
|
|
*/
|
|
p = addr & PAGE_MASK;
|
|
size = PAGE_ALIGN(addr + size) - p;
|
|
|
|
/*
|
|
* Don't allow anybody to remap normal RAM that we're using.
|
|
* mem_init() sets high_memory so only do the check after that.
|
|
*
|
|
* However, allow remap of rootfs: TBD
|
|
*/
|
|
if (mem_init_done &&
|
|
p >= memory_start && p < virt_to_phys(high_memory) &&
|
|
!(p >= virt_to_phys((unsigned long)&__bss_stop) &&
|
|
p < virt_to_phys((unsigned long)__bss_stop))) {
|
|
printk(KERN_WARNING "__ioremap(): phys addr "PTE_FMT
|
|
" is RAM lr %p\n", (unsigned long)p,
|
|
__builtin_return_address(0));
|
|
return NULL;
|
|
}
|
|
|
|
if (size == 0)
|
|
return NULL;
|
|
|
|
/*
|
|
* Is it already mapped? If the whole area is mapped then we're
|
|
* done, otherwise remap it since we want to keep the virt addrs for
|
|
* each request contiguous.
|
|
*
|
|
* We make the assumption here that if the bottom and top
|
|
* of the range we want are mapped then it's mapped to the
|
|
* same virt address (and this is contiguous).
|
|
* -- Cort
|
|
*/
|
|
|
|
if (mem_init_done) {
|
|
struct vm_struct *area;
|
|
area = get_vm_area(size, VM_IOREMAP);
|
|
if (area == NULL)
|
|
return NULL;
|
|
v = VMALLOC_VMADDR(area->addr);
|
|
} else {
|
|
v = (ioremap_bot -= size);
|
|
}
|
|
|
|
if ((flags & _PAGE_PRESENT) == 0)
|
|
flags |= _PAGE_KERNEL;
|
|
if (flags & _PAGE_NO_CACHE)
|
|
flags |= _PAGE_GUARDED;
|
|
|
|
err = 0;
|
|
for (i = 0; i < size && err == 0; i += PAGE_SIZE)
|
|
err = map_page(v + i, p + i, flags);
|
|
if (err) {
|
|
if (mem_init_done)
|
|
vfree((void *)v);
|
|
return NULL;
|
|
}
|
|
|
|
return (void __iomem *) (v + ((unsigned long)addr & ~PAGE_MASK));
|
|
}
|
|
|
|
void __iomem *ioremap(phys_addr_t addr, unsigned long size)
|
|
{
|
|
return __ioremap(addr, size, _PAGE_NO_CACHE);
|
|
}
|
|
EXPORT_SYMBOL(ioremap);
|
|
|
|
void iounmap(void *addr)
|
|
{
|
|
if (addr > high_memory && (unsigned long) addr < ioremap_bot)
|
|
vfree((void *) (PAGE_MASK & (unsigned long) addr));
|
|
}
|
|
EXPORT_SYMBOL(iounmap);
|
|
|
|
|
|
int map_page(unsigned long va, phys_addr_t pa, int flags)
|
|
{
|
|
pmd_t *pd;
|
|
pte_t *pg;
|
|
int err = -ENOMEM;
|
|
/* spin_lock(&init_mm.page_table_lock); */
|
|
/* Use upper 10 bits of VA to index the first level map */
|
|
pd = pmd_offset(pgd_offset_k(va), va);
|
|
/* Use middle 10 bits of VA to index the second-level map */
|
|
pg = pte_alloc_kernel(pd, va); /* from powerpc - pgtable.c */
|
|
/* pg = pte_alloc_kernel(&init_mm, pd, va); */
|
|
|
|
if (pg != NULL) {
|
|
err = 0;
|
|
set_pte_at(&init_mm, va, pg, pfn_pte(pa >> PAGE_SHIFT,
|
|
__pgprot(flags)));
|
|
if (mem_init_done)
|
|
flush_HPTE(0, va, pmd_val(*pd));
|
|
/* flush_HPTE(0, va, pg); */
|
|
|
|
}
|
|
/* spin_unlock(&init_mm.page_table_lock); */
|
|
return err;
|
|
}
|
|
|
|
void __init adjust_total_lowmem(void)
|
|
{
|
|
/* TBD */
|
|
#if 0
|
|
unsigned long max_low_mem = MAX_LOW_MEM;
|
|
|
|
if (total_lowmem > max_low_mem) {
|
|
total_lowmem = max_low_mem;
|
|
#ifndef CONFIG_HIGHMEM
|
|
printk(KERN_INFO "Warning, memory limited to %ld Mb, use "
|
|
"CONFIG_HIGHMEM to reach %ld Mb\n",
|
|
max_low_mem >> 20, total_memory >> 20);
|
|
total_memory = total_lowmem;
|
|
#endif /* CONFIG_HIGHMEM */
|
|
}
|
|
#endif
|
|
}
|
|
|
|
static void show_tmem(unsigned long tmem)
|
|
{
|
|
volatile unsigned long a;
|
|
a = a + tmem;
|
|
}
|
|
|
|
/*
|
|
* Map in all of physical memory starting at CONFIG_KERNEL_START.
|
|
*/
|
|
void __init mapin_ram(void)
|
|
{
|
|
unsigned long v, p, s, f;
|
|
|
|
v = CONFIG_KERNEL_START;
|
|
p = memory_start;
|
|
show_tmem(memory_size);
|
|
for (s = 0; s < memory_size; s += PAGE_SIZE) {
|
|
f = _PAGE_PRESENT | _PAGE_ACCESSED |
|
|
_PAGE_SHARED | _PAGE_HWEXEC;
|
|
if ((char *) v < _stext || (char *) v >= _etext)
|
|
f |= _PAGE_WRENABLE;
|
|
else
|
|
/* On the MicroBlaze, no user access
|
|
forces R/W kernel access */
|
|
f |= _PAGE_USER;
|
|
map_page(v, p, f);
|
|
v += PAGE_SIZE;
|
|
p += PAGE_SIZE;
|
|
}
|
|
}
|
|
|
|
/* is x a power of 2? */
|
|
#define is_power_of_2(x) ((x) != 0 && (((x) & ((x) - 1)) == 0))
|
|
|
|
/*
|
|
* Set up a mapping for a block of I/O.
|
|
* virt, phys, size must all be page-aligned.
|
|
* This should only be called before ioremap is called.
|
|
*/
|
|
void __init io_block_mapping(unsigned long virt, phys_addr_t phys,
|
|
unsigned int size, int flags)
|
|
{
|
|
int i;
|
|
|
|
if (virt > CONFIG_KERNEL_START && virt < ioremap_bot)
|
|
ioremap_bot = ioremap_base = virt;
|
|
|
|
/* Put it in the page tables. */
|
|
for (i = 0; i < size; i += PAGE_SIZE)
|
|
map_page(virt + i, phys + i, flags);
|
|
}
|
|
|
|
/* Scan the real Linux page tables and return a PTE pointer for
|
|
* a virtual address in a context.
|
|
* Returns true (1) if PTE was found, zero otherwise. The pointer to
|
|
* the PTE pointer is unmodified if PTE is not found.
|
|
*/
|
|
static int get_pteptr(struct mm_struct *mm, unsigned long addr, pte_t **ptep)
|
|
{
|
|
pgd_t *pgd;
|
|
pmd_t *pmd;
|
|
pte_t *pte;
|
|
int retval = 0;
|
|
|
|
pgd = pgd_offset(mm, addr & PAGE_MASK);
|
|
if (pgd) {
|
|
pmd = pmd_offset(pgd, addr & PAGE_MASK);
|
|
if (pmd_present(*pmd)) {
|
|
pte = pte_offset_kernel(pmd, addr & PAGE_MASK);
|
|
if (pte) {
|
|
retval = 1;
|
|
*ptep = pte;
|
|
}
|
|
}
|
|
}
|
|
return retval;
|
|
}
|
|
|
|
/* Find physical address for this virtual address. Normally used by
|
|
* I/O functions, but anyone can call it.
|
|
*/
|
|
unsigned long iopa(unsigned long addr)
|
|
{
|
|
unsigned long pa;
|
|
|
|
pte_t *pte;
|
|
struct mm_struct *mm;
|
|
|
|
/* Allow mapping of user addresses (within the thread)
|
|
* for DMA if necessary.
|
|
*/
|
|
if (addr < TASK_SIZE)
|
|
mm = current->mm;
|
|
else
|
|
mm = &init_mm;
|
|
|
|
pa = 0;
|
|
if (get_pteptr(mm, addr, &pte))
|
|
pa = (pte_val(*pte) & PAGE_MASK) | (addr & ~PAGE_MASK);
|
|
|
|
return pa;
|
|
}
|