xref: /openbmc/linux/arch/m68k/mm/init.c (revision 57c8a661)
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 #if !defined(CONFIG_SUN3) && !defined(CONFIG_COLDFIRE)
44 extern void init_pointer_table(unsigned long ptable);
45 extern pmd_t *zero_pgtable;
46 #endif
47 
48 #ifdef CONFIG_MMU
49 
50 pg_data_t pg_data_map[MAX_NUMNODES];
51 EXPORT_SYMBOL(pg_data_map);
52 
53 int m68k_virt_to_node_shift;
54 
55 #ifndef CONFIG_SINGLE_MEMORY_CHUNK
56 pg_data_t *pg_data_table[65];
57 EXPORT_SYMBOL(pg_data_table);
58 #endif
59 
60 void __init m68k_setup_node(int node)
61 {
62 #ifndef CONFIG_SINGLE_MEMORY_CHUNK
63 	struct m68k_mem_info *info = m68k_memory + node;
64 	int i, end;
65 
66 	i = (unsigned long)phys_to_virt(info->addr) >> __virt_to_node_shift();
67 	end = (unsigned long)phys_to_virt(info->addr + info->size - 1) >> __virt_to_node_shift();
68 	for (; i <= end; i++) {
69 		if (pg_data_table[i])
70 			pr_warn("overlap at %u for chunk %u\n", i, node);
71 		pg_data_table[i] = pg_data_map + node;
72 	}
73 #endif
74 	node_set_online(node);
75 }
76 
77 #else /* CONFIG_MMU */
78 
79 /*
80  * paging_init() continues the virtual memory environment setup which
81  * was begun by the code in arch/head.S.
82  * The parameters are pointers to where to stick the starting and ending
83  * addresses of available kernel virtual memory.
84  */
85 void __init paging_init(void)
86 {
87 	/*
88 	 * Make sure start_mem is page aligned, otherwise bootmem and
89 	 * page_alloc get different views of the world.
90 	 */
91 	unsigned long end_mem = memory_end & PAGE_MASK;
92 	unsigned long zones_size[MAX_NR_ZONES] = { 0, };
93 
94 	high_memory = (void *) end_mem;
95 
96 	empty_zero_page = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
97 
98 	/*
99 	 * Set up SFC/DFC registers (user data space).
100 	 */
101 	set_fs (USER_DS);
102 
103 	zones_size[ZONE_DMA] = (end_mem - PAGE_OFFSET) >> PAGE_SHIFT;
104 	free_area_init(zones_size);
105 }
106 
107 #endif /* CONFIG_MMU */
108 
109 void free_initmem(void)
110 {
111 #ifndef CONFIG_MMU_SUN3
112 	free_initmem_default(-1);
113 #endif /* CONFIG_MMU_SUN3 */
114 }
115 
116 #if defined(CONFIG_MMU) && !defined(CONFIG_COLDFIRE)
117 #define VECTORS	&vectors[0]
118 #else
119 #define VECTORS	_ramvec
120 #endif
121 
122 static inline void init_pointer_tables(void)
123 {
124 #if defined(CONFIG_MMU) && !defined(CONFIG_SUN3) && !defined(CONFIG_COLDFIRE)
125 	int i;
126 
127 	/* insert pointer tables allocated so far into the tablelist */
128 	init_pointer_table((unsigned long)kernel_pg_dir);
129 	for (i = 0; i < PTRS_PER_PGD; i++) {
130 		if (pgd_present(kernel_pg_dir[i]))
131 			init_pointer_table(__pgd_page(kernel_pg_dir[i]));
132 	}
133 
134 	/* insert also pointer table that we used to unmap the zero page */
135 	if (zero_pgtable)
136 		init_pointer_table((unsigned long)zero_pgtable);
137 #endif
138 }
139 
140 void __init mem_init(void)
141 {
142 	/* this will put all memory onto the freelists */
143 	memblock_free_all();
144 	init_pointer_tables();
145 	mem_init_print_info(NULL);
146 }
147 
148 #ifdef CONFIG_BLK_DEV_INITRD
149 void free_initrd_mem(unsigned long start, unsigned long end)
150 {
151 	free_reserved_area((void *)start, (void *)end, -1, "initrd");
152 }
153 #endif
154