1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* |
3 | * PowerPC version |
4 | * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org) |
5 | * |
6 | * Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au) |
7 | * and Cort Dougan (PReP) (cort@cs.nmt.edu) |
8 | * Copyright (C) 1996 Paul Mackerras |
9 | * PPC44x/36-bit changes by Matt Porter (mporter@mvista.com) |
10 | * |
11 | * Derived from "arch/i386/mm/init.c" |
12 | * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds |
13 | */ |
14 | |
15 | #include <linux/module.h> |
16 | #include <linux/sched.h> |
17 | #include <linux/kernel.h> |
18 | #include <linux/errno.h> |
19 | #include <linux/string.h> |
20 | #include <linux/types.h> |
21 | #include <linux/mm.h> |
22 | #include <linux/stddef.h> |
23 | #include <linux/init.h> |
24 | #include <linux/highmem.h> |
25 | #include <linux/initrd.h> |
26 | #include <linux/pagemap.h> |
27 | #include <linux/memblock.h> |
28 | #include <linux/gfp.h> |
29 | #include <linux/slab.h> |
30 | #include <linux/hugetlb.h> |
31 | |
32 | #include <asm/io.h> |
33 | #include <asm/mmu.h> |
34 | #include <asm/smp.h> |
35 | #include <asm/machdep.h> |
36 | #include <asm/btext.h> |
37 | #include <asm/tlb.h> |
38 | #include <asm/sections.h> |
39 | #include <asm/hugetlb.h> |
40 | #include <asm/kup.h> |
41 | #include <asm/kasan.h> |
42 | #include <asm/fixmap.h> |
43 | |
44 | #include <mm/mmu_decl.h> |
45 | |
46 | #if defined(CONFIG_KERNEL_START_BOOL) || defined(CONFIG_LOWMEM_SIZE_BOOL) |
47 | /* The amount of lowmem must be within 0xF0000000 - KERNELBASE. */ |
48 | #if (CONFIG_LOWMEM_SIZE > (0xF0000000 - PAGE_OFFSET)) |
49 | #error "You must adjust CONFIG_LOWMEM_SIZE or CONFIG_KERNEL_START" |
50 | #endif |
51 | #endif |
52 | #define MAX_LOW_MEM CONFIG_LOWMEM_SIZE |
53 | |
54 | phys_addr_t total_memory; |
55 | phys_addr_t total_lowmem; |
56 | |
57 | #ifdef CONFIG_RELOCATABLE |
58 | /* Used in __va()/__pa() */ |
59 | long long virt_phys_offset; |
60 | EXPORT_SYMBOL(virt_phys_offset); |
61 | #endif |
62 | |
63 | phys_addr_t lowmem_end_addr; |
64 | |
65 | int boot_mapsize; |
66 | #ifdef CONFIG_PPC_PMAC |
67 | unsigned long agp_special_page; |
68 | EXPORT_SYMBOL(agp_special_page); |
69 | #endif |
70 | |
71 | void MMU_init(void); |
72 | |
73 | /* max amount of low RAM to map in */ |
74 | unsigned long __max_low_memory = MAX_LOW_MEM; |
75 | |
76 | /* |
77 | * MMU_init sets up the basic memory mappings for the kernel, |
78 | * including both RAM and possibly some I/O regions, |
79 | * and sets up the page tables and the MMU hardware ready to go. |
80 | */ |
81 | void __init MMU_init(void) |
82 | { |
83 | if (ppc_md.progress) |
84 | ppc_md.progress("MMU:enter" , 0x111); |
85 | |
86 | total_lowmem = total_memory = memblock_end_of_DRAM() - memstart_addr; |
87 | lowmem_end_addr = memstart_addr + total_lowmem; |
88 | |
89 | #ifdef CONFIG_PPC_85xx |
90 | /* Freescale Book-E parts expect lowmem to be mapped by fixed TLB |
91 | * entries, so we need to adjust lowmem to match the amount we can map |
92 | * in the fixed entries */ |
93 | adjust_total_lowmem(); |
94 | #endif /* CONFIG_PPC_85xx */ |
95 | |
96 | if (total_lowmem > __max_low_memory) { |
97 | total_lowmem = __max_low_memory; |
98 | lowmem_end_addr = memstart_addr + total_lowmem; |
99 | #ifndef CONFIG_HIGHMEM |
100 | total_memory = total_lowmem; |
101 | memblock_enforce_memory_limit(memory_limit: total_lowmem); |
102 | #endif /* CONFIG_HIGHMEM */ |
103 | } |
104 | |
105 | /* Initialize the MMU hardware */ |
106 | if (ppc_md.progress) |
107 | ppc_md.progress("MMU:hw init" , 0x300); |
108 | MMU_init_hw(); |
109 | |
110 | /* Map in all of RAM starting at KERNELBASE */ |
111 | if (ppc_md.progress) |
112 | ppc_md.progress("MMU:mapin" , 0x301); |
113 | mapin_ram(); |
114 | |
115 | /* Initialize early top-down ioremap allocator */ |
116 | ioremap_bot = IOREMAP_TOP; |
117 | |
118 | if (ppc_md.progress) |
119 | ppc_md.progress("MMU:exit" , 0x211); |
120 | |
121 | /* From now on, btext is no longer BAT mapped if it was at all */ |
122 | #ifdef CONFIG_BOOTX_TEXT |
123 | btext_unmap(); |
124 | #endif |
125 | |
126 | kasan_mmu_init(); |
127 | |
128 | setup_kup(); |
129 | |
130 | update_mmu_feature_fixups(MMU_FTR_KUAP); |
131 | |
132 | /* Shortly after that, the entire linear mapping will be available */ |
133 | memblock_set_current_limit(limit: lowmem_end_addr); |
134 | } |
135 | |