/*
* Modifications by Matt Porter (mporter@mvista.com) to support
* PPC44x Book E processors.
*
* This file contains the routines for initializing the MMU
* on the 4xx series of chips.
* -- 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 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/ptrace.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/highmem.h>
#include <asm/pgalloc.h>
#include <asm/prom.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/bootx.h>
#include <asm/machdep.h>
#include <asm/setup.h>
#include "mmu_decl.h"
extern char etext[], _stext[];
/* Used by the 44x TLB replacement exception handler.
* Just needed it declared someplace.
*/
unsigned int tlb_44x_index = 0;
unsigned int tlb_44x_hwater = 62;
/*
* "Pins" a 256MB TLB entry in AS0 for kernel lowmem
*/
static void __init
ppc44x_pin_tlb(int slot, unsigned int virt, unsigned int phys)
{
unsigned long attrib = 0;
__asm__ __volatile__("\
clrrwi %2,%2,10\n\
ori %2,%2,%4\n\
clrrwi %1,%1,10\n\
li %0,0\n\
ori %0,%0,%5\n\
tlbwe %2,%3,%6\n\
tlbwe %1,%3,%7\n\
tlbwe %0,%3,%8"
:
: "r" (attrib), "r" (phys), "r" (virt), "r" (slot),
"i" (PPC44x_TLB_VALID | PPC44x_TLB_256M),
"i" (PPC44x_TLB_SW | PPC44x_TLB_SR | PPC44x_TLB_SX | PPC44x_TLB_G),
"i" (PPC44x_TLB_PAGEID),
"i" (PPC44x_TLB_XLAT),
"i" (PPC44x_TLB_ATTRIB));
}
/*
* MMU_init_hw does the chip-specific initialization of the MMU hardware.
*/
void __init MMU_init_hw(void)
{
flush_instruction_cache();
}
unsigned long __init mmu_mapin_ram(void)
{
unsigned int pinned_tlbs = 1;
int i;
/* Determine number of entries necessary to cover lowmem */
pinned_tlbs = (unsigned int)
(_ALIGN(total_lowmem, PPC44x_PIN_SIZE) >> PPC44x_PIN_SHIFT);
/* Write upper watermark to save location */
tlb_44x_hwater = PPC44x_LOW_SLOT - pinned_tlbs;
/* If necessary, set additional pinned TLBs */
if (pinned_tlbs > 1)
for (i = (PPC44x_LOW_SLOT-(pinned_tlbs-1)); i < PPC44x_LOW_SLOT; i++) {
unsigned int phys_addr = (PPC44x_LOW_SLOT-i) * PPC44x_PIN_SIZE;
ppc44x_pin_tlb(i, phys_addr+PAGE_OFFSET, phys_addr);
}
return total_lowmem;
}
