/*
* 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
*
* 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/init.h>
#include <asm/mmu.h>
#include <asm/system.h>
#include <asm/page.h>
#include "mmu_decl.h"
/* Used by the 44x TLB replacement exception handler.
* Just needed it declared someplace.
*/
unsigned int tlb_44x_index; /* = 0 */
unsigned int tlb_44x_hwater = PPC44x_TLB_SIZE - 1 - PPC44x_EARLY_TLBS;
/*
* "Pins" a 256MB TLB entry in AS0 for kernel lowmem
*/
static void __init ppc44x_pin_tlb(unsigned int virt, unsigned int phys)
{
__asm__ __volatile__(
"tlbwe %2,%3,%4\n"
"tlbwe %1,%3,%5\n"
"tlbwe %0,%3,%6\n"
:
: "r" (PPC44x_TLB_SW | PPC44x_TLB_SR | PPC44x_TLB_SX | PPC44x_TLB_G),
"r" (phys),
"r" (virt | PPC44x_TLB_VALID | PPC44x_TLB_256M),
"r" (tlb_44x_hwater--), /* slot for this TLB entry */
"i" (PPC44x_TLB_PAGEID),
"i" (PPC44x_TLB_XLAT),
"i" (PPC44x_TLB_ATTRIB));
}
void __init MMU_init_hw(void)
{
flush_instruction_cache();
}
unsigned long __init mmu_mapin_ram(void)
{
unsigned long addr;
/* Pin in enough TLBs to cover any lowmem not covered by the
* initial 256M mapping established in head_44x.S */
for (addr = PPC_PIN_SIZE; addr < total_lowmem;
addr += PPC_PIN_SIZE)
ppc44x_pin_tlb(addr + PAGE_OFFSET, addr);
return total_lowmem;
}
