diff options
Diffstat (limited to 'arch/powerpc/mm/44x_mmu.c')
| -rw-r--r-- | arch/powerpc/mm/44x_mmu.c | 120 |
1 files changed, 120 insertions, 0 deletions
diff --git a/arch/powerpc/mm/44x_mmu.c b/arch/powerpc/mm/44x_mmu.c new file mode 100644 index 00000000000..3d79ce281b6 --- /dev/null +++ b/arch/powerpc/mm/44x_mmu.c @@ -0,0 +1,120 @@ +/* + * 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/config.h> +#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; +} |