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
45 #ifdef CONFIG_BLK_DEV_INITRD
setup_initrd(void)46 static void __init setup_initrd(void)
47 {
48 unsigned long size;
49
50 if (initrd_start >= initrd_end) {
51 pr_err("initrd not found or empty");
52 goto disable;
53 }
54
55 if (__pa(initrd_end) > PFN_PHYS(max_low_pfn)) {
56 pr_err("initrd extends beyond end of memory");
57 goto disable;
58 }
59
60 size = initrd_end - initrd_start;
61
62 if (memblock_is_region_reserved(__pa(initrd_start), size)) {
63 pr_err("INITRD: 0x%08lx+0x%08lx overlaps in-use memory region",
64 __pa(initrd_start), size);
65 goto disable;
66 }
67
68 memblock_reserve(__pa(initrd_start), size);
69
70 pr_info("Initial ramdisk at: 0x%p (%lu bytes)\n",
71 (void *)(initrd_start), size);
72
73 initrd_below_start_ok = 1;
74
75 return;
76
77 disable:
78 initrd_start = initrd_end = 0;
79
80 pr_err(" - disabling initrd\n");
81 }
82 #endif
83
mem_init(void)84 void __init mem_init(void)
85 {
86 #ifdef CONFIG_HIGHMEM
87 unsigned long tmp;
88
89 set_max_mapnr(highend_pfn - ARCH_PFN_OFFSET);
90 #else
91 set_max_mapnr(max_low_pfn - ARCH_PFN_OFFSET);
92 #endif
93 high_memory = (void *) __va(max_low_pfn << PAGE_SHIFT);
94
95 #ifdef CONFIG_BLK_DEV_INITRD
96 setup_initrd();
97 #endif
98
99 memblock_free_all();
100
101 #ifdef CONFIG_HIGHMEM
102 for (tmp = highstart_pfn; tmp < highend_pfn; tmp++) {
103 struct page *page = pfn_to_page(tmp);
104
105 /* FIXME not sure about */
106 if (!memblock_is_reserved(tmp << PAGE_SHIFT))
107 free_highmem_page(page);
108 }
109 #endif
110 }
111
free_initmem(void)112 void free_initmem(void)
113 {
114 free_initmem_default(-1);
115 }
116
pgd_init(unsigned long * p)117 void pgd_init(unsigned long *p)
118 {
119 int i;
120
121 for (i = 0; i < PTRS_PER_PGD; i++)
122 p[i] = __pa(invalid_pte_table);
123
124 flush_tlb_all();
125 local_icache_inv_all(NULL);
126 }
127
mmu_init(unsigned long min_pfn,unsigned long max_pfn)128 void __init mmu_init(unsigned long min_pfn, unsigned long max_pfn)
129 {
130 int i;
131
132 for (i = 0; i < USER_PTRS_PER_PGD; i++)
133 swapper_pg_dir[i].pgd = __pa(invalid_pte_table);
134
135 for (i = USER_PTRS_PER_PGD; i < PTRS_PER_PGD; i++)
136 swapper_pg_dir[i].pgd =
137 __pa(kernel_pte_tables + (PTRS_PER_PTE * (i - USER_PTRS_PER_PGD)));
138
139 for (i = 0; i < PTRS_KERN_TABLE; i++)
140 set_pte(&kernel_pte_tables[i], __pte(_PAGE_GLOBAL));
141
142 for (i = min_pfn; i < max_pfn; i++)
143 set_pte(&kernel_pte_tables[i - PFN_DOWN(va_pa_offset)], pfn_pte(i, PAGE_KERNEL));
144
145 flush_tlb_all();
146 local_icache_inv_all(NULL);
147
148 /* Setup page mask to 4k */
149 write_mmu_pagemask(0);
150
151 setup_pgd(swapper_pg_dir, 0);
152 }
153
fixrange_init(unsigned long start,unsigned long end,pgd_t * pgd_base)154 void __init fixrange_init(unsigned long start, unsigned long end,
155 pgd_t *pgd_base)
156 {
157 pgd_t *pgd;
158 pud_t *pud;
159 pmd_t *pmd;
160 pte_t *pte;
161 int i, j, k;
162 unsigned long vaddr;
163
164 vaddr = start;
165 i = pgd_index(vaddr);
166 j = pud_index(vaddr);
167 k = pmd_index(vaddr);
168 pgd = pgd_base + i;
169
170 for ( ; (i < PTRS_PER_PGD) && (vaddr != end); pgd++, i++) {
171 pud = (pud_t *)pgd;
172 for ( ; (j < PTRS_PER_PUD) && (vaddr != end); pud++, j++) {
173 pmd = (pmd_t *)pud;
174 for (; (k < PTRS_PER_PMD) && (vaddr != end); pmd++, k++) {
175 if (pmd_none(*pmd)) {
176 pte = (pte_t *) memblock_alloc_low(PAGE_SIZE, PAGE_SIZE);
177 if (!pte)
178 panic("%s: Failed to allocate %lu bytes align=%lx\n",
179 __func__, PAGE_SIZE,
180 PAGE_SIZE);
181
182 set_pmd(pmd, __pmd(__pa(pte)));
183 BUG_ON(pte != pte_offset_kernel(pmd, 0));
184 }
185 vaddr += PMD_SIZE;
186 }
187 k = 0;
188 }
189 j = 0;
190 }
191 }
192
fixaddr_init(void)193 void __init fixaddr_init(void)
194 {
195 unsigned long vaddr;
196
197 vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK;
198 fixrange_init(vaddr, vaddr + PMD_SIZE, swapper_pg_dir);
199 }
200
201 static const pgprot_t protection_map[16] = {
202 [VM_NONE] = PAGE_NONE,
203 [VM_READ] = PAGE_READ,
204 [VM_WRITE] = PAGE_READ,
205 [VM_WRITE | VM_READ] = PAGE_READ,
206 [VM_EXEC] = PAGE_READ,
207 [VM_EXEC | VM_READ] = PAGE_READ,
208 [VM_EXEC | VM_WRITE] = PAGE_READ,
209 [VM_EXEC | VM_WRITE | VM_READ] = PAGE_READ,
210 [VM_SHARED] = PAGE_NONE,
211 [VM_SHARED | VM_READ] = PAGE_READ,
212 [VM_SHARED | VM_WRITE] = PAGE_WRITE,
213 [VM_SHARED | VM_WRITE | VM_READ] = PAGE_WRITE,
214 [VM_SHARED | VM_EXEC] = PAGE_READ,
215 [VM_SHARED | VM_EXEC | VM_READ] = PAGE_READ,
216 [VM_SHARED | VM_EXEC | VM_WRITE] = PAGE_WRITE,
217 [VM_SHARED | VM_EXEC | VM_WRITE | VM_READ] = PAGE_WRITE
218 };
219 DECLARE_VM_GET_PAGE_PROT
220
