diff options
Diffstat (limited to 'arch/powerpc/mm/4xx_mmu.c')
| -rw-r--r-- | arch/powerpc/mm/4xx_mmu.c | 141 |
1 files changed, 141 insertions, 0 deletions
diff --git a/arch/powerpc/mm/4xx_mmu.c b/arch/powerpc/mm/4xx_mmu.c new file mode 100644 index 00000000000..b7bcbc232f3 --- /dev/null +++ b/arch/powerpc/mm/4xx_mmu.c @@ -0,0 +1,141 @@ +/* + * 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 int __map_without_ltlbs; +/* + * MMU_init_hw does the chip-specific initialization of the MMU hardware. + */ +void __init MMU_init_hw(void) +{ + /* + * The Zone Protection Register (ZPR) defines how protection will + * be applied to every page which is a member of a given zone. At + * present, we utilize only two of the 4xx's zones. + * The zone index bits (of ZSEL) in the PTE are used for software + * indicators, except the LSB. For user access, zone 1 is used, + * for kernel access, zone 0 is used. We set all but zone 1 + * to zero, allowing only kernel access as indicated in the PTE. + * For zone 1, we set a 01 binary (a value of 10 will not work) + * to allow user access as indicated in the PTE. This also allows + * kernel access as indicated in the PTE. + */ + + mtspr(SPRN_ZPR, 0x10000000); + + flush_instruction_cache(); + + /* + * Set up the real-mode cache parameters for the exception vector + * handlers (which are run in real-mode). + */ + + mtspr(SPRN_DCWR, 0x00000000); /* All caching is write-back */ + + /* + * Cache instruction and data space where the exception + * vectors and the kernel live in real-mode. + */ + + mtspr(SPRN_DCCR, 0xF0000000); /* 512 MB of data space at 0x0. */ + mtspr(SPRN_ICCR, 0xF0000000); /* 512 MB of instr. space at 0x0. */ +} + +#define LARGE_PAGE_SIZE_16M (1<<24) +#define LARGE_PAGE_SIZE_4M (1<<22) + +unsigned long __init mmu_mapin_ram(void) +{ + unsigned long v, s; + phys_addr_t p; + + v = KERNELBASE; + p = PPC_MEMSTART; + s = 0; + + if (__map_without_ltlbs) { + return s; + } + + while (s <= (total_lowmem - LARGE_PAGE_SIZE_16M)) { + pmd_t *pmdp; + unsigned long val = p | _PMD_SIZE_16M | _PAGE_HWEXEC | _PAGE_HWWRITE; + + spin_lock(&init_mm.page_table_lock); + pmdp = pmd_offset(pgd_offset_k(v), v); + pmd_val(*pmdp++) = val; + pmd_val(*pmdp++) = val; + pmd_val(*pmdp++) = val; + pmd_val(*pmdp++) = val; + spin_unlock(&init_mm.page_table_lock); + + v += LARGE_PAGE_SIZE_16M; + p += LARGE_PAGE_SIZE_16M; + s += LARGE_PAGE_SIZE_16M; + } + + while (s <= (total_lowmem - LARGE_PAGE_SIZE_4M)) { + pmd_t *pmdp; + unsigned long val = p | _PMD_SIZE_4M | _PAGE_HWEXEC | _PAGE_HWWRITE; + + spin_lock(&init_mm.page_table_lock); + pmdp = pmd_offset(pgd_offset_k(v), v); + pmd_val(*pmdp) = val; + spin_unlock(&init_mm.page_table_lock); + + v += LARGE_PAGE_SIZE_4M; + p += LARGE_PAGE_SIZE_4M; + s += LARGE_PAGE_SIZE_4M; + } + + return s; +} |