diff options
Diffstat (limited to 'arch/cris/arch-v32/mm/init.c')
| -rw-r--r-- | arch/cris/arch-v32/mm/init.c | 174 |
1 files changed, 174 insertions, 0 deletions
diff --git a/arch/cris/arch-v32/mm/init.c b/arch/cris/arch-v32/mm/init.c new file mode 100644 index 00000000000..f2fba27d822 --- /dev/null +++ b/arch/cris/arch-v32/mm/init.c @@ -0,0 +1,174 @@ +/* + * Set up paging and the MMU. + * + * Copyright (C) 2000-2003, Axis Communications AB. + * + * Authors: Bjorn Wesen <bjornw@axis.com> + * Tobias Anderberg <tobiasa@axis.com>, CRISv32 port. + */ +#include <linux/config.h> +#include <linux/mmzone.h> +#include <linux/init.h> +#include <linux/bootmem.h> +#include <linux/mm.h> +#include <linux/config.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 +cris_mmu_init(void) +{ + 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; + +#ifdef CONFIG_SMP + { + pgd_t **pgd; + pgd = (pgd_t**)&per_cpu(current_pgd, smp_processor_id()); + SUPP_BANK_SEL(1); + SUPP_REG_WR(RW_MM_TLB_PGD, pgd); + SUPP_BANK_SEL(2); + SUPP_REG_WR(RW_MM_TLB_PGD, pgd); + } +#endif + + /* Initialise the TLB. Function found in tlb.c. */ + tlb_init(); + + /* 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) | +#ifndef CONFIG_ETRAXFS_SIM + REG_STATE(mmu, rw_mm_cfg, seg_a, page) | +#else + REG_STATE(mmu, rw_mm_cfg, seg_a, linear) | +#endif + 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) | +#ifndef CONFIG_ETRAXFS_SIM + REG_FIELD(mmu, rw_mm_kbase_hi, base_c, 0x4) | +#else + REG_FIELD(mmu, rw_mm_kbase_hi, base_c, 0x0) | +#endif + REG_FIELD(mmu, rw_mm_kbase_hi, base_b, 0xb) | +#ifndef CONFIG_ETRAXFS_SIM + REG_FIELD(mmu, rw_mm_kbase_hi, base_a, 0x0) | +#else + REG_FIELD(mmu, rw_mm_kbase_hi, base_a, 0xa) | +#endif + 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_BANK_SEL(BANK_IM); + 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_BANK_SEL(BANK_DM); + 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); + + SPEC_REG_WR(SPEC_REG_PID, 0); + + /* + * The MMU has been enabled ever since head.S but just to make it + * totally obvious enable it here as well. + */ + SUPP_BANK_SEL(BANK_GC); + SUPP_REG_WR(RW_GC_CFG, 0xf); /* IMMU, DMMU, ICache, DCache on */ +} + +void __init +paging_init(void) +{ + 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); + + cris_mmu_init(); + + /* + * 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; +} |