xref: /linux/arch/m68k/mm/init.c (revision c5d3cdad688ed75fb311a3a671eb30ba7106d7d3)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *  linux/arch/m68k/mm/init.c
4  *
5  *  Copyright (C) 1995  Hamish Macdonald
6  *
7  *  Contains common initialization routines, specific init code moved
8  *  to motorola.c and sun3mmu.c
9  */
10 
11 #include <linux/module.h>
12 #include <linux/signal.h>
13 #include <linux/sched.h>
14 #include <linux/mm.h>
15 #include <linux/swap.h>
16 #include <linux/kernel.h>
17 #include <linux/string.h>
18 #include <linux/types.h>
19 #include <linux/init.h>
20 #include <linux/memblock.h>
21 #include <linux/gfp.h>
22 
23 #include <asm/setup.h>
24 #include <linux/uaccess.h>
25 #include <asm/page.h>
26 #include <asm/pgalloc.h>
27 #include <asm/traps.h>
28 #include <asm/machdep.h>
29 #include <asm/io.h>
30 #ifdef CONFIG_ATARI
31 #include <asm/atari_stram.h>
32 #endif
33 #include <asm/sections.h>
34 #include <asm/tlb.h>
35 
36 /*
37  * ZERO_PAGE is a special page that is used for zero-initialized
38  * data and COW.
39  */
40 void *empty_zero_page;
41 EXPORT_SYMBOL(empty_zero_page);
42 
43 #ifdef CONFIG_MMU
44 
45 pg_data_t pg_data_map[MAX_NUMNODES];
46 EXPORT_SYMBOL(pg_data_map);
47 
48 int m68k_virt_to_node_shift;
49 
50 #ifndef CONFIG_SINGLE_MEMORY_CHUNK
51 pg_data_t *pg_data_table[65];
52 EXPORT_SYMBOL(pg_data_table);
53 #endif
54 
55 void __init m68k_setup_node(int node)
56 {
57 #ifndef CONFIG_SINGLE_MEMORY_CHUNK
58 	struct m68k_mem_info *info = m68k_memory + node;
59 	int i, end;
60 
61 	i = (unsigned long)phys_to_virt(info->addr) >> __virt_to_node_shift();
62 	end = (unsigned long)phys_to_virt(info->addr + info->size - 1) >> __virt_to_node_shift();
63 	for (; i <= end; i++) {
64 		if (pg_data_table[i])
65 			pr_warn("overlap at %u for chunk %u\n", i, node);
66 		pg_data_table[i] = pg_data_map + node;
67 	}
68 #endif
69 	node_set_online(node);
70 }
71 
72 #else /* CONFIG_MMU */
73 
74 /*
75  * paging_init() continues the virtual memory environment setup which
76  * was begun by the code in arch/head.S.
77  * The parameters are pointers to where to stick the starting and ending
78  * addresses of available kernel virtual memory.
79  */
80 void __init paging_init(void)
81 {
82 	/*
83 	 * Make sure start_mem is page aligned, otherwise bootmem and
84 	 * page_alloc get different views of the world.
85 	 */
86 	unsigned long end_mem = memory_end & PAGE_MASK;
87 	unsigned long zones_size[MAX_NR_ZONES] = { 0, };
88 
89 	high_memory = (void *) end_mem;
90 
91 	empty_zero_page = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
92 	if (!empty_zero_page)
93 		panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
94 		      __func__, PAGE_SIZE, PAGE_SIZE);
95 
96 	/*
97 	 * Set up SFC/DFC registers (user data space).
98 	 */
99 	set_fs (USER_DS);
100 
101 	zones_size[ZONE_DMA] = (end_mem - PAGE_OFFSET) >> PAGE_SHIFT;
102 	free_area_init(zones_size);
103 }
104 
105 #endif /* CONFIG_MMU */
106 
107 void free_initmem(void)
108 {
109 #ifndef CONFIG_MMU_SUN3
110 	free_initmem_default(-1);
111 #endif /* CONFIG_MMU_SUN3 */
112 }
113 
114 #if defined(CONFIG_MMU) && !defined(CONFIG_COLDFIRE)
115 #define VECTORS	&vectors[0]
116 #else
117 #define VECTORS	_ramvec
118 #endif
119 
120 static inline void init_pointer_tables(void)
121 {
122 #if defined(CONFIG_MMU) && !defined(CONFIG_SUN3) && !defined(CONFIG_COLDFIRE)
123 	int i, j;
124 
125 	/* insert pointer tables allocated so far into the tablelist */
126 	init_pointer_table(kernel_pg_dir, TABLE_PGD);
127 	for (i = 0; i < PTRS_PER_PGD; i++) {
128 		pud_t *pud = (pud_t *)&kernel_pg_dir[i];
129 		pmd_t *pmd_dir;
130 
131 		if (!pud_present(*pud))
132 			continue;
133 
134 		pmd_dir = (pmd_t *)pgd_page_vaddr(kernel_pg_dir[i]);
135 		init_pointer_table(pmd_dir, TABLE_PMD);
136 
137 		for (j = 0; j < PTRS_PER_PMD; j++) {
138 			pmd_t *pmd = &pmd_dir[j];
139 			pte_t *pte_dir;
140 
141 			if (!pmd_present(*pmd))
142 				continue;
143 
144 			pte_dir = (pte_t *)__pmd_page(*pmd);
145 			init_pointer_table(pte_dir, TABLE_PTE);
146 		}
147 	}
148 #endif
149 }
150 
151 void __init mem_init(void)
152 {
153 	/* this will put all memory onto the freelists */
154 	memblock_free_all();
155 	init_pointer_tables();
156 	mem_init_print_info(NULL);
157 }
158