tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1// SPDX-License-Identifier: GPL-2.0
2// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
3
4#include <linux/bug.h>
5#include <linux/module.h>
6#include <linux/init.h>
7#include <linux/signal.h>
8#include <linux/sched.h>
9#include <linux/kernel.h>
10#include <linux/errno.h>
11#include <linux/string.h>
12#include <linux/types.h>
13#include <linux/pagemap.h>
14#include <linux/ptrace.h>
15#include <linux/mman.h>
16#include <linux/mm.h>
17#include <linux/highmem.h>
18#include <linux/memblock.h>
19#include <linux/swap.h>
20#include <linux/proc_fs.h>
21#include <linux/pfn.h>
22#include <linux/initrd.h>
23
24#include <asm/setup.h>
25#include <asm/cachectl.h>
26#include <asm/dma.h>
27#include <asm/pgtable.h>
28#include <asm/pgalloc.h>
29#include <asm/mmu_context.h>
30#include <asm/sections.h>
31#include <asm/tlb.h>
32
33pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
34pte_t invalid_pte_table[PTRS_PER_PTE] __page_aligned_bss;
35EXPORT_SYMBOL(invalid_pte_table);
36unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)]
37 __page_aligned_bss;
38EXPORT_SYMBOL(empty_zero_page);
39
40#ifdef CONFIG_BLK_DEV_INITRD
41static void __init setup_initrd(void)
42{
43 unsigned long size;
44
45 if (initrd_start >= initrd_end) {
46 pr_err("initrd not found or empty");
47 goto disable;
48 }
49
50 if (__pa(initrd_end) > PFN_PHYS(max_low_pfn)) {
51 pr_err("initrd extends beyond end of memory");
52 goto disable;
53 }
54
55 size = initrd_end - initrd_start;
56
57 if (memblock_is_region_reserved(__pa(initrd_start), size)) {
58 pr_err("INITRD: 0x%08lx+0x%08lx overlaps in-use memory region",
59 __pa(initrd_start), size);
60 goto disable;
61 }
62
63 memblock_reserve(__pa(initrd_start), size);
64
65 pr_info("Initial ramdisk at: 0x%p (%lu bytes)\n",
66 (void *)(initrd_start), size);
67
68 initrd_below_start_ok = 1;
69
70 return;
71
72disable:
73 initrd_start = initrd_end = 0;
74
75 pr_err(" - disabling initrd\n");
76}
77#endif
78
79void __init mem_init(void)
80{
81#ifdef CONFIG_HIGHMEM
82 unsigned long tmp;
83
84 max_mapnr = highend_pfn;
85#else
86 max_mapnr = max_low_pfn;
87#endif
88 high_memory = (void *) __va(max_low_pfn << PAGE_SHIFT);
89
90#ifdef CONFIG_BLK_DEV_INITRD
91 setup_initrd();
92#endif
93
94 memblock_free_all();
95
96#ifdef CONFIG_HIGHMEM
97 for (tmp = highstart_pfn; tmp < highend_pfn; tmp++) {
98 struct page *page = pfn_to_page(tmp);
99
100 /* FIXME not sure about */
101 if (!memblock_is_reserved(tmp << PAGE_SHIFT))
102 free_highmem_page(page);
103 }
104#endif
105 mem_init_print_info(NULL);
106}
107
108extern char __init_begin[], __init_end[];
109
110void free_initmem(void)
111{
112 unsigned long addr;
113
114 addr = (unsigned long) &__init_begin;
115
116 while (addr < (unsigned long) &__init_end) {
117 ClearPageReserved(virt_to_page(addr));
118 init_page_count(virt_to_page(addr));
119 free_page(addr);
120 totalram_pages_inc();
121 addr += PAGE_SIZE;
122 }
123
124 pr_info("Freeing unused kernel memory: %dk freed\n",
125 ((unsigned int)&__init_end - (unsigned int)&__init_begin) >> 10);
126}
127
128void pgd_init(unsigned long *p)
129{
130 int i;
131
132 for (i = 0; i < PTRS_PER_PGD; i++)
133 p[i] = __pa(invalid_pte_table);
134}
135
136void __init pre_mmu_init(void)
137{
138 /*
139 * Setup page-table and enable TLB-hardrefill
140 */
141 flush_tlb_all();
142 pgd_init((unsigned long *)swapper_pg_dir);
143 TLBMISS_HANDLER_SETUP_PGD(swapper_pg_dir);
144 TLBMISS_HANDLER_SETUP_PGD_KERNEL(swapper_pg_dir);
145
146 /* Setup page mask to 4k */
147 write_mmu_pagemask(0);
148}
149
150void __init fixrange_init(unsigned long start, unsigned long end,
151 pgd_t *pgd_base)
152{
153 pgd_t *pgd;
154 pud_t *pud;
155 pmd_t *pmd;
156 pte_t *pte;
157 int i, j, k;
158 unsigned long vaddr;
159
160 vaddr = start;
161 i = __pgd_offset(vaddr);
162 j = __pud_offset(vaddr);
163 k = __pmd_offset(vaddr);
164 pgd = pgd_base + i;
165
166 for ( ; (i < PTRS_PER_PGD) && (vaddr != end); pgd++, i++) {
167 pud = (pud_t *)pgd;
168 for ( ; (j < PTRS_PER_PUD) && (vaddr != end); pud++, j++) {
169 pmd = (pmd_t *)pud;
170 for (; (k < PTRS_PER_PMD) && (vaddr != end); pmd++, k++) {
171 if (pmd_none(*pmd)) {
172 pte = (pte_t *) memblock_alloc_low(PAGE_SIZE, PAGE_SIZE);
173 if (!pte)
174 panic("%s: Failed to allocate %lu bytes align=%lx\n",
175 __func__, PAGE_SIZE,
176 PAGE_SIZE);
177
178 set_pmd(pmd, __pmd(__pa(pte)));
179 BUG_ON(pte != pte_offset_kernel(pmd, 0));
180 }
181 vaddr += PMD_SIZE;
182 }
183 k = 0;
184 }
185 j = 0;
186 }
187}
188
189void __init fixaddr_init(void)
190{
191 unsigned long vaddr;
192
193 vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK;
194 fixrange_init(vaddr, vaddr + PMD_SIZE, swapper_pg_dir);
195}