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/pgalloc.h>
28 #include <asm/mmu_context.h>
29 #include <asm/sections.h>
30 #include <asm/tlb.h>
31 #include <asm/cacheflush.h>
32
33 #define PTRS_KERN_TABLE \
34 ((PTRS_PER_PGD - USER_PTRS_PER_PGD) * PTRS_PER_PTE)
35
36 pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
37 pte_t invalid_pte_table[PTRS_PER_PTE] __page_aligned_bss;
38 pte_t kernel_pte_tables[PTRS_KERN_TABLE] __page_aligned_bss;
39
40 EXPORT_SYMBOL(invalid_pte_table);
41 unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)]
42 __page_aligned_bss;
43 EXPORT_SYMBOL(empty_zero_page);
44
free_initmem(void)45 void free_initmem(void)
46 {
47 free_initmem_default(-1);
48 }
49
pgd_init(unsigned long * p)50 void pgd_init(unsigned long *p)
51 {
52 int i;
53
54 for (i = 0; i < PTRS_PER_PGD; i++)
55 p[i] = __pa(invalid_pte_table);
56
57 flush_tlb_all();
58 local_icache_inv_all(NULL);
59 }
60
mmu_init(unsigned long min_pfn,unsigned long max_pfn)61 void __init mmu_init(unsigned long min_pfn, unsigned long max_pfn)
62 {
63 int i;
64
65 for (i = 0; i < USER_PTRS_PER_PGD; i++)
66 swapper_pg_dir[i].pgd = __pa(invalid_pte_table);
67
68 for (i = USER_PTRS_PER_PGD; i < PTRS_PER_PGD; i++)
69 swapper_pg_dir[i].pgd =
70 __pa(kernel_pte_tables + (PTRS_PER_PTE * (i - USER_PTRS_PER_PGD)));
71
72 for (i = 0; i < PTRS_KERN_TABLE; i++)
73 set_pte(&kernel_pte_tables[i], __pte(_PAGE_GLOBAL));
74
75 for (i = min_pfn; i < max_pfn; i++)
76 set_pte(&kernel_pte_tables[i - PFN_DOWN(va_pa_offset)], pfn_pte(i, PAGE_KERNEL));
77
78 flush_tlb_all();
79 local_icache_inv_all(NULL);
80
81 /* Setup page mask to 4k */
82 write_mmu_pagemask(0);
83
84 setup_pgd(swapper_pg_dir, 0);
85 }
86
fixrange_init(unsigned long start,unsigned long end,pgd_t * pgd_base)87 void __init fixrange_init(unsigned long start, unsigned long end,
88 pgd_t *pgd_base)
89 {
90 pgd_t *pgd;
91 pud_t *pud;
92 pmd_t *pmd;
93 pte_t *pte;
94 int i, j, k;
95 unsigned long vaddr;
96
97 vaddr = start;
98 i = pgd_index(vaddr);
99 j = pud_index(vaddr);
100 k = pmd_index(vaddr);
101 pgd = pgd_base + i;
102
103 for ( ; (i < PTRS_PER_PGD) && (vaddr != end); pgd++, i++) {
104 pud = (pud_t *)pgd;
105 for ( ; (j < PTRS_PER_PUD) && (vaddr != end); pud++, j++) {
106 pmd = (pmd_t *)pud;
107 for (; (k < PTRS_PER_PMD) && (vaddr != end); pmd++, k++) {
108 if (pmd_none(*pmd)) {
109 pte = (pte_t *) memblock_alloc_low(PAGE_SIZE, PAGE_SIZE);
110 if (!pte)
111 panic("%s: Failed to allocate %lu bytes align=%lx\n",
112 __func__, PAGE_SIZE,
113 PAGE_SIZE);
114
115 set_pmd(pmd, __pmd(__pa(pte)));
116 BUG_ON(pte != pte_offset_kernel(pmd, 0));
117 }
118 vaddr += PMD_SIZE;
119 }
120 k = 0;
121 }
122 j = 0;
123 }
124 }
125
fixaddr_init(void)126 void __init fixaddr_init(void)
127 {
128 unsigned long vaddr;
129
130 vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK;
131 fixrange_init(vaddr, vaddr + PMD_SIZE, swapper_pg_dir);
132 }
133
134 static const pgprot_t protection_map[16] = {
135 [VM_NONE] = PAGE_NONE,
136 [VM_READ] = PAGE_READ,
137 [VM_WRITE] = PAGE_READ,
138 [VM_WRITE | VM_READ] = PAGE_READ,
139 [VM_EXEC] = PAGE_READ,
140 [VM_EXEC | VM_READ] = PAGE_READ,
141 [VM_EXEC | VM_WRITE] = PAGE_READ,
142 [VM_EXEC | VM_WRITE | VM_READ] = PAGE_READ,
143 [VM_SHARED] = PAGE_NONE,
144 [VM_SHARED | VM_READ] = PAGE_READ,
145 [VM_SHARED | VM_WRITE] = PAGE_WRITE,
146 [VM_SHARED | VM_WRITE | VM_READ] = PAGE_WRITE,
147 [VM_SHARED | VM_EXEC] = PAGE_READ,
148 [VM_SHARED | VM_EXEC | VM_READ] = PAGE_READ,
149 [VM_SHARED | VM_EXEC | VM_WRITE] = PAGE_WRITE,
150 [VM_SHARED | VM_EXEC | VM_WRITE | VM_READ] = PAGE_WRITE
151 };
152 DECLARE_VM_GET_PAGE_PROT
153