blob: a84ba7ff22d269e40780d6225927022884497d8a [file] [log] [blame]
* Set up paging and the MMU.
* Copyright (C) 2000-2003, Axis Communications AB.
* Authors: Bjorn Wesen <>
* Tobias Anderberg <>, CRISv32 port.
#include <linux/mmzone.h>
#include <linux/init.h>
#include <linux/bootmem.h>
#include <linux/mm.h>
#include <asm/pgtable.h>
#include <asm/page.h>
#include <asm/types.h>
#include <asm/mmu.h>
#include <asm/io.h>
#include <asm/mmu_context.h>
#include <asm/arch/hwregs/asm/mmu_defs_asm.h>
#include <asm/arch/hwregs/supp_reg.h>
extern void tlb_init(void);
* The kernel is already mapped with linear mapping at kseg_c so there's no
* need to map it with a page table. However, head.S also temporarily mapped it
* at kseg_4 thus the ksegs are set up again. Also clear the TLB and do various
* other paging stuff.
void __init
unsigned long mmu_config;
unsigned long mmu_kbase_hi;
unsigned long mmu_kbase_lo;
unsigned short mmu_page_id;
* Make sure the current pgd table points to something sane, even if it
* is most probably not used until the next switch_mm.
per_cpu(current_pgd, smp_processor_id()) = init_mm.pgd;
pgd_t **pgd;
pgd = (pgd_t**)&per_cpu(current_pgd, smp_processor_id());
/* Initialise the TLB. Function found in tlb.c. */
/* Enable exceptions and initialize the kernel segments. */
mmu_config = ( REG_STATE(mmu, rw_mm_cfg, we, on) |
REG_STATE(mmu, rw_mm_cfg, acc, on) |
REG_STATE(mmu, rw_mm_cfg, ex, on) |
REG_STATE(mmu, rw_mm_cfg, inv, on) |
REG_STATE(mmu, rw_mm_cfg, seg_f, linear) |
REG_STATE(mmu, rw_mm_cfg, seg_e, linear) |
REG_STATE(mmu, rw_mm_cfg, seg_d, page) |
REG_STATE(mmu, rw_mm_cfg, seg_c, linear) |
REG_STATE(mmu, rw_mm_cfg, seg_b, linear) |
REG_STATE(mmu, rw_mm_cfg, seg_a, page) |
REG_STATE(mmu, rw_mm_cfg, seg_a, linear) |
REG_STATE(mmu, rw_mm_cfg, seg_9, page) |
REG_STATE(mmu, rw_mm_cfg, seg_8, page) |
REG_STATE(mmu, rw_mm_cfg, seg_7, page) |
REG_STATE(mmu, rw_mm_cfg, seg_6, page) |
REG_STATE(mmu, rw_mm_cfg, seg_5, page) |
REG_STATE(mmu, rw_mm_cfg, seg_4, page) |
REG_STATE(mmu, rw_mm_cfg, seg_3, page) |
REG_STATE(mmu, rw_mm_cfg, seg_2, page) |
REG_STATE(mmu, rw_mm_cfg, seg_1, page) |
REG_STATE(mmu, rw_mm_cfg, seg_0, page));
mmu_kbase_hi = ( REG_FIELD(mmu, rw_mm_kbase_hi, base_f, 0x0) |
REG_FIELD(mmu, rw_mm_kbase_hi, base_e, 0x8) |
REG_FIELD(mmu, rw_mm_kbase_hi, base_d, 0x0) |
REG_FIELD(mmu, rw_mm_kbase_hi, base_c, 0x4) |
REG_FIELD(mmu, rw_mm_kbase_hi, base_c, 0x0) |
REG_FIELD(mmu, rw_mm_kbase_hi, base_b, 0xb) |
REG_FIELD(mmu, rw_mm_kbase_hi, base_a, 0x0) |
REG_FIELD(mmu, rw_mm_kbase_hi, base_a, 0xa) |
REG_FIELD(mmu, rw_mm_kbase_hi, base_9, 0x0) |
REG_FIELD(mmu, rw_mm_kbase_hi, base_8, 0x0));
mmu_kbase_lo = ( REG_FIELD(mmu, rw_mm_kbase_lo, base_7, 0x0) |
REG_FIELD(mmu, rw_mm_kbase_lo, base_6, 0x0) |
REG_FIELD(mmu, rw_mm_kbase_lo, base_5, 0x0) |
REG_FIELD(mmu, rw_mm_kbase_lo, base_4, 0x0) |
REG_FIELD(mmu, rw_mm_kbase_lo, base_3, 0x0) |
REG_FIELD(mmu, rw_mm_kbase_lo, base_2, 0x0) |
REG_FIELD(mmu, rw_mm_kbase_lo, base_1, 0x0) |
REG_FIELD(mmu, rw_mm_kbase_lo, base_0, 0x0));
mmu_page_id = REG_FIELD(mmu, rw_mm_tlb_hi, pid, 0);
/* Update the instruction MMU. */
SUPP_REG_WR(RW_MM_CFG, mmu_config);
SUPP_REG_WR(RW_MM_KBASE_HI, mmu_kbase_hi);
SUPP_REG_WR(RW_MM_KBASE_LO, mmu_kbase_lo);
SUPP_REG_WR(RW_MM_TLB_HI, mmu_page_id);
/* Update the data MMU. */
SUPP_REG_WR(RW_MM_CFG, mmu_config);
SUPP_REG_WR(RW_MM_KBASE_HI, mmu_kbase_hi);
SUPP_REG_WR(RW_MM_KBASE_LO, mmu_kbase_lo);
SUPP_REG_WR(RW_MM_TLB_HI, mmu_page_id);
* The MMU has been enabled ever since head.S but just to make it
* totally obvious enable it here as well.
SUPP_REG_WR(RW_GC_CFG, 0xf); /* IMMU, DMMU, ICache, DCache on */
void __init
int i;
unsigned long zones_size[MAX_NR_ZONES];
printk("Setting up paging and the MMU.\n");
/* Clear out the init_mm.pgd that will contain the kernel's mappings. */
for(i = 0; i < PTRS_PER_PGD; i++)
swapper_pg_dir[i] = __pgd(0);
* Initialize the bad page table and bad page to point to a couple of
* allocated pages.
empty_zero_page = (unsigned long) alloc_bootmem_pages(PAGE_SIZE);
memset((void *) empty_zero_page, 0, PAGE_SIZE);
/* All pages are DMA'able in Etrax, so put all in the DMA'able zone. */
zones_size[0] = ((unsigned long) high_memory - PAGE_OFFSET) >> PAGE_SHIFT;
for (i = 1; i < MAX_NR_ZONES; i++)
zones_size[i] = 0;
* Use free_area_init_node instead of free_area_init, because it is
* designed for systems where the DRAM starts at an address
* substantially higher than 0, like us (we start at PAGE_OFFSET). This
* saves space in the mem_map page array.
free_area_init_node(0, &contig_page_data, zones_size, PAGE_OFFSET >> PAGE_SHIFT, 0);
mem_map = contig_page_data.node_mem_map;