xref: /openbmc/linux/arch/m68k/mm/init.c (revision 63705da3)
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 int m68k_virt_to_node_shift;
46 
47 void __init m68k_setup_node(int node)
48 {
49 	node_set_online(node);
50 }
51 
52 #else /* CONFIG_MMU */
53 
54 /*
55  * paging_init() continues the virtual memory environment setup which
56  * was begun by the code in arch/head.S.
57  * The parameters are pointers to where to stick the starting and ending
58  * addresses of available kernel virtual memory.
59  */
60 void __init paging_init(void)
61 {
62 	/*
63 	 * Make sure start_mem is page aligned, otherwise bootmem and
64 	 * page_alloc get different views of the world.
65 	 */
66 	unsigned long end_mem = memory_end & PAGE_MASK;
67 	unsigned long max_zone_pfn[MAX_NR_ZONES] = { 0, };
68 
69 	high_memory = (void *) end_mem;
70 
71 	empty_zero_page = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
72 	if (!empty_zero_page)
73 		panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
74 		      __func__, PAGE_SIZE, PAGE_SIZE);
75 	max_zone_pfn[ZONE_DMA] = end_mem >> PAGE_SHIFT;
76 	free_area_init(max_zone_pfn);
77 }
78 
79 #endif /* CONFIG_MMU */
80 
81 void free_initmem(void)
82 {
83 #ifndef CONFIG_MMU_SUN3
84 	free_initmem_default(-1);
85 #endif /* CONFIG_MMU_SUN3 */
86 }
87 
88 #if defined(CONFIG_MMU) && !defined(CONFIG_COLDFIRE)
89 #define VECTORS	&vectors[0]
90 #else
91 #define VECTORS	_ramvec
92 #endif
93 
94 static inline void init_pointer_tables(void)
95 {
96 #if defined(CONFIG_MMU) && !defined(CONFIG_SUN3) && !defined(CONFIG_COLDFIRE)
97 	int i, j;
98 
99 	/* insert pointer tables allocated so far into the tablelist */
100 	init_pointer_table(kernel_pg_dir, TABLE_PGD);
101 	for (i = 0; i < PTRS_PER_PGD; i++) {
102 		pud_t *pud = (pud_t *)&kernel_pg_dir[i];
103 		pmd_t *pmd_dir;
104 
105 		if (!pud_present(*pud))
106 			continue;
107 
108 		pmd_dir = (pmd_t *)pgd_page_vaddr(kernel_pg_dir[i]);
109 		init_pointer_table(pmd_dir, TABLE_PMD);
110 
111 		for (j = 0; j < PTRS_PER_PMD; j++) {
112 			pmd_t *pmd = &pmd_dir[j];
113 			pte_t *pte_dir;
114 
115 			if (!pmd_present(*pmd))
116 				continue;
117 
118 			pte_dir = (pte_t *)pmd_page_vaddr(*pmd);
119 			init_pointer_table(pte_dir, TABLE_PTE);
120 		}
121 	}
122 #endif
123 }
124 
125 void __init mem_init(void)
126 {
127 	/* this will put all memory onto the freelists */
128 	memblock_free_all();
129 	init_pointer_tables();
130 }
131