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51533b61 MS |
1 | /* |
2 | * Set up paging and the MMU. | |
3 | * | |
4 | * Copyright (C) 2000-2003, Axis Communications AB. | |
5 | * | |
6 | * Authors: Bjorn Wesen <bjornw@axis.com> | |
7 | * Tobias Anderberg <tobiasa@axis.com>, CRISv32 port. | |
8 | */ | |
51533b61 MS |
9 | #include <linux/mmzone.h> |
10 | #include <linux/init.h> | |
11 | #include <linux/bootmem.h> | |
12 | #include <linux/mm.h> | |
51533b61 MS |
13 | #include <asm/pgtable.h> |
14 | #include <asm/page.h> | |
15 | #include <asm/types.h> | |
16 | #include <asm/mmu.h> | |
17 | #include <asm/io.h> | |
18 | #include <asm/mmu_context.h> | |
19 | #include <asm/arch/hwregs/asm/mmu_defs_asm.h> | |
20 | #include <asm/arch/hwregs/supp_reg.h> | |
21 | ||
22 | extern void tlb_init(void); | |
23 | ||
24 | /* | |
25 | * The kernel is already mapped with linear mapping at kseg_c so there's no | |
26 | * need to map it with a page table. However, head.S also temporarily mapped it | |
27 | * at kseg_4 thus the ksegs are set up again. Also clear the TLB and do various | |
28 | * other paging stuff. | |
29 | */ | |
30 | void __init | |
31 | cris_mmu_init(void) | |
32 | { | |
33 | unsigned long mmu_config; | |
34 | unsigned long mmu_kbase_hi; | |
35 | unsigned long mmu_kbase_lo; | |
36 | unsigned short mmu_page_id; | |
37 | ||
38 | /* | |
39 | * Make sure the current pgd table points to something sane, even if it | |
40 | * is most probably not used until the next switch_mm. | |
41 | */ | |
42 | per_cpu(current_pgd, smp_processor_id()) = init_mm.pgd; | |
43 | ||
44 | #ifdef CONFIG_SMP | |
45 | { | |
46 | pgd_t **pgd; | |
47 | pgd = (pgd_t**)&per_cpu(current_pgd, smp_processor_id()); | |
48 | SUPP_BANK_SEL(1); | |
49 | SUPP_REG_WR(RW_MM_TLB_PGD, pgd); | |
50 | SUPP_BANK_SEL(2); | |
51 | SUPP_REG_WR(RW_MM_TLB_PGD, pgd); | |
52 | } | |
53 | #endif | |
54 | ||
55 | /* Initialise the TLB. Function found in tlb.c. */ | |
56 | tlb_init(); | |
57 | ||
58 | /* Enable exceptions and initialize the kernel segments. */ | |
59 | mmu_config = ( REG_STATE(mmu, rw_mm_cfg, we, on) | | |
60 | REG_STATE(mmu, rw_mm_cfg, acc, on) | | |
61 | REG_STATE(mmu, rw_mm_cfg, ex, on) | | |
62 | REG_STATE(mmu, rw_mm_cfg, inv, on) | | |
63 | REG_STATE(mmu, rw_mm_cfg, seg_f, linear) | | |
64 | REG_STATE(mmu, rw_mm_cfg, seg_e, linear) | | |
65 | REG_STATE(mmu, rw_mm_cfg, seg_d, page) | | |
66 | REG_STATE(mmu, rw_mm_cfg, seg_c, linear) | | |
67 | REG_STATE(mmu, rw_mm_cfg, seg_b, linear) | | |
0836c6d2 | 68 | #ifndef CONFIG_ETRAX_VCS_SIM |
51533b61 MS |
69 | REG_STATE(mmu, rw_mm_cfg, seg_a, page) | |
70 | #else | |
71 | REG_STATE(mmu, rw_mm_cfg, seg_a, linear) | | |
72 | #endif | |
73 | REG_STATE(mmu, rw_mm_cfg, seg_9, page) | | |
74 | REG_STATE(mmu, rw_mm_cfg, seg_8, page) | | |
75 | REG_STATE(mmu, rw_mm_cfg, seg_7, page) | | |
76 | REG_STATE(mmu, rw_mm_cfg, seg_6, page) | | |
77 | REG_STATE(mmu, rw_mm_cfg, seg_5, page) | | |
78 | REG_STATE(mmu, rw_mm_cfg, seg_4, page) | | |
79 | REG_STATE(mmu, rw_mm_cfg, seg_3, page) | | |
80 | REG_STATE(mmu, rw_mm_cfg, seg_2, page) | | |
81 | REG_STATE(mmu, rw_mm_cfg, seg_1, page) | | |
82 | REG_STATE(mmu, rw_mm_cfg, seg_0, page)); | |
83 | ||
84 | mmu_kbase_hi = ( REG_FIELD(mmu, rw_mm_kbase_hi, base_f, 0x0) | | |
85 | REG_FIELD(mmu, rw_mm_kbase_hi, base_e, 0x8) | | |
86 | REG_FIELD(mmu, rw_mm_kbase_hi, base_d, 0x0) | | |
51533b61 | 87 | REG_FIELD(mmu, rw_mm_kbase_hi, base_c, 0x4) | |
51533b61 | 88 | REG_FIELD(mmu, rw_mm_kbase_hi, base_b, 0xb) | |
0836c6d2 | 89 | #ifndef CONFIG_ETRAX_VCS_SIM |
51533b61 MS |
90 | REG_FIELD(mmu, rw_mm_kbase_hi, base_a, 0x0) | |
91 | #else | |
92 | REG_FIELD(mmu, rw_mm_kbase_hi, base_a, 0xa) | | |
93 | #endif | |
94 | REG_FIELD(mmu, rw_mm_kbase_hi, base_9, 0x0) | | |
95 | REG_FIELD(mmu, rw_mm_kbase_hi, base_8, 0x0)); | |
96 | ||
97 | mmu_kbase_lo = ( REG_FIELD(mmu, rw_mm_kbase_lo, base_7, 0x0) | | |
98 | REG_FIELD(mmu, rw_mm_kbase_lo, base_6, 0x0) | | |
99 | REG_FIELD(mmu, rw_mm_kbase_lo, base_5, 0x0) | | |
100 | REG_FIELD(mmu, rw_mm_kbase_lo, base_4, 0x0) | | |
101 | REG_FIELD(mmu, rw_mm_kbase_lo, base_3, 0x0) | | |
102 | REG_FIELD(mmu, rw_mm_kbase_lo, base_2, 0x0) | | |
103 | REG_FIELD(mmu, rw_mm_kbase_lo, base_1, 0x0) | | |
104 | REG_FIELD(mmu, rw_mm_kbase_lo, base_0, 0x0)); | |
105 | ||
106 | mmu_page_id = REG_FIELD(mmu, rw_mm_tlb_hi, pid, 0); | |
107 | ||
108 | /* Update the instruction MMU. */ | |
109 | SUPP_BANK_SEL(BANK_IM); | |
110 | SUPP_REG_WR(RW_MM_CFG, mmu_config); | |
111 | SUPP_REG_WR(RW_MM_KBASE_HI, mmu_kbase_hi); | |
112 | SUPP_REG_WR(RW_MM_KBASE_LO, mmu_kbase_lo); | |
113 | SUPP_REG_WR(RW_MM_TLB_HI, mmu_page_id); | |
114 | ||
115 | /* Update the data MMU. */ | |
116 | SUPP_BANK_SEL(BANK_DM); | |
117 | SUPP_REG_WR(RW_MM_CFG, mmu_config); | |
118 | SUPP_REG_WR(RW_MM_KBASE_HI, mmu_kbase_hi); | |
119 | SUPP_REG_WR(RW_MM_KBASE_LO, mmu_kbase_lo); | |
120 | SUPP_REG_WR(RW_MM_TLB_HI, mmu_page_id); | |
121 | ||
122 | SPEC_REG_WR(SPEC_REG_PID, 0); | |
123 | ||
124 | /* | |
125 | * The MMU has been enabled ever since head.S but just to make it | |
126 | * totally obvious enable it here as well. | |
127 | */ | |
128 | SUPP_BANK_SEL(BANK_GC); | |
129 | SUPP_REG_WR(RW_GC_CFG, 0xf); /* IMMU, DMMU, ICache, DCache on */ | |
130 | } | |
131 | ||
132 | void __init | |
133 | paging_init(void) | |
134 | { | |
135 | int i; | |
136 | unsigned long zones_size[MAX_NR_ZONES]; | |
137 | ||
138 | printk("Setting up paging and the MMU.\n"); | |
139 | ||
140 | /* Clear out the init_mm.pgd that will contain the kernel's mappings. */ | |
141 | for(i = 0; i < PTRS_PER_PGD; i++) | |
142 | swapper_pg_dir[i] = __pgd(0); | |
143 | ||
144 | cris_mmu_init(); | |
145 | ||
146 | /* | |
147 | * Initialize the bad page table and bad page to point to a couple of | |
148 | * allocated pages. | |
149 | */ | |
150 | empty_zero_page = (unsigned long) alloc_bootmem_pages(PAGE_SIZE); | |
151 | memset((void *) empty_zero_page, 0, PAGE_SIZE); | |
152 | ||
153 | /* All pages are DMA'able in Etrax, so put all in the DMA'able zone. */ | |
154 | zones_size[0] = ((unsigned long) high_memory - PAGE_OFFSET) >> PAGE_SHIFT; | |
155 | ||
156 | for (i = 1; i < MAX_NR_ZONES; i++) | |
157 | zones_size[i] = 0; | |
158 | ||
159 | /* | |
160 | * Use free_area_init_node instead of free_area_init, because it is | |
161 | * designed for systems where the DRAM starts at an address | |
162 | * substantially higher than 0, like us (we start at PAGE_OFFSET). This | |
163 | * saves space in the mem_map page array. | |
164 | */ | |
9109fb7b | 165 | free_area_init_node(0, zones_size, PAGE_OFFSET >> PAGE_SHIFT, 0); |
51533b61 MS |
166 | |
167 | mem_map = contig_page_data.node_mem_map; | |
168 | } |