--- /dev/null
+/*
+ * 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/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 <arch/hwregs/asm/mmu_defs_asm.h>
+#include <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;
+
+ /* Initialise the TLB. Function found in tlb.c. */
+ tlb_init();
+
+ /*
+ * Enable exceptions and initialize the kernel segments.
+ * See head.S for differences between ARTPEC-3 and ETRAX FS.
+ */
+ 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) |
+#ifdef CONFIG_CRIS_MACH_ARTPEC3
+ REG_STATE(mmu, rw_mm_cfg, seg_f, page) |
+ REG_STATE(mmu, rw_mm_cfg, seg_e, page) |
+ REG_STATE(mmu, rw_mm_cfg, seg_d, linear) |
+#else
+ 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) |
+#endif
+ 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_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));
+
+ /* See head.S for differences between ARTPEC-3 and ETRAX FS. */
+ mmu_kbase_hi = ( REG_FIELD(mmu, rw_mm_kbase_hi, base_f, 0x0) |
+#ifdef CONFIG_CRIS_MACH_ARTPEC3
+ REG_FIELD(mmu, rw_mm_kbase_hi, base_e, 0x0) |
+ REG_FIELD(mmu, rw_mm_kbase_hi, base_d, 0x5) |
+#else
+ REG_FIELD(mmu, rw_mm_kbase_hi, base_e, 0x8) |
+ REG_FIELD(mmu, rw_mm_kbase_hi, base_d, 0x0) |
+#endif
+ REG_FIELD(mmu, rw_mm_kbase_hi, base_c, 0x4) |
+ 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_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, zones_size, PAGE_OFFSET >> PAGE_SHIFT, 0);
+
+ mem_map = contig_page_data.node_mem_map;
+}
Code Review / kvmfornfv.git / blobdiff