xref: /linux/arch/csky/mm/init.c (revision de008c9ba5684f14e83bcf86cd45fb0e4e6c4d82)
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 
42 void free_initmem(void)
43 {
44 	free_initmem_default(-1);
45 }
46 
47 void pgd_init(unsigned long *p)
48 {
49 	int i;
50 
51 	for (i = 0; i < PTRS_PER_PGD; i++)
52 		p[i] = __pa(invalid_pte_table);
53 
54 	flush_tlb_all();
55 	local_icache_inv_all(NULL);
56 }
57 
58 void __init mmu_init(unsigned long min_pfn, unsigned long max_pfn)
59 {
60 	int i;
61 
62 	for (i = 0; i < USER_PTRS_PER_PGD; i++)
63 		swapper_pg_dir[i].pgd = __pa(invalid_pte_table);
64 
65 	for (i = USER_PTRS_PER_PGD; i < PTRS_PER_PGD; i++)
66 		swapper_pg_dir[i].pgd =
67 			__pa(kernel_pte_tables + (PTRS_PER_PTE * (i - USER_PTRS_PER_PGD)));
68 
69 	for (i = 0; i < PTRS_KERN_TABLE; i++)
70 		set_pte(&kernel_pte_tables[i], __pte(_PAGE_GLOBAL));
71 
72 	for (i = min_pfn; i < max_pfn; i++)
73 		set_pte(&kernel_pte_tables[i - PFN_DOWN(va_pa_offset)], pfn_pte(i, PAGE_KERNEL));
74 
75 	flush_tlb_all();
76 	local_icache_inv_all(NULL);
77 
78 	/* Setup page mask to 4k */
79 	write_mmu_pagemask(0);
80 
81 	setup_pgd(swapper_pg_dir, 0);
82 }
83 
84 void __init fixrange_init(unsigned long start, unsigned long end,
85 			pgd_t *pgd_base)
86 {
87 	pgd_t *pgd;
88 	pud_t *pud;
89 	pmd_t *pmd;
90 	pte_t *pte;
91 	int i, j, k;
92 	unsigned long vaddr;
93 
94 	vaddr = start;
95 	i = pgd_index(vaddr);
96 	j = pud_index(vaddr);
97 	k = pmd_index(vaddr);
98 	pgd = pgd_base + i;
99 
100 	for ( ; (i < PTRS_PER_PGD) && (vaddr != end); pgd++, i++) {
101 		pud = (pud_t *)pgd;
102 		for ( ; (j < PTRS_PER_PUD) && (vaddr != end); pud++, j++) {
103 			pmd = (pmd_t *)pud;
104 			for (; (k < PTRS_PER_PMD) && (vaddr != end); pmd++, k++) {
105 				if (pmd_none(*pmd)) {
106 					pte = (pte_t *) memblock_alloc_low(PAGE_SIZE, PAGE_SIZE);
107 					if (!pte)
108 						panic("%s: Failed to allocate %lu bytes align=%lx\n",
109 						      __func__, PAGE_SIZE,
110 						      PAGE_SIZE);
111 
112 					set_pmd(pmd, __pmd(__pa(pte)));
113 					BUG_ON(pte != pte_offset_kernel(pmd, 0));
114 				}
115 				vaddr += PMD_SIZE;
116 			}
117 			k = 0;
118 		}
119 		j = 0;
120 	}
121 }
122 
123 void __init fixaddr_init(void)
124 {
125 	unsigned long vaddr;
126 
127 	vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK;
128 	fixrange_init(vaddr, vaddr + PMD_SIZE, swapper_pg_dir);
129 }
130 
131 static const pgprot_t protection_map[16] = {
132 	[VM_NONE]					= PAGE_NONE,
133 	[VM_READ]					= PAGE_READ,
134 	[VM_WRITE]					= PAGE_READ,
135 	[VM_WRITE | VM_READ]				= PAGE_READ,
136 	[VM_EXEC]					= PAGE_READ,
137 	[VM_EXEC | VM_READ]				= PAGE_READ,
138 	[VM_EXEC | VM_WRITE]				= PAGE_READ,
139 	[VM_EXEC | VM_WRITE | VM_READ]			= PAGE_READ,
140 	[VM_SHARED]					= PAGE_NONE,
141 	[VM_SHARED | VM_READ]				= PAGE_READ,
142 	[VM_SHARED | VM_WRITE]				= PAGE_WRITE,
143 	[VM_SHARED | VM_WRITE | VM_READ]		= PAGE_WRITE,
144 	[VM_SHARED | VM_EXEC]				= PAGE_READ,
145 	[VM_SHARED | VM_EXEC | VM_READ]			= PAGE_READ,
146 	[VM_SHARED | VM_EXEC | VM_WRITE]		= PAGE_WRITE,
147 	[VM_SHARED | VM_EXEC | VM_WRITE | VM_READ]	= PAGE_WRITE
148 };
149 DECLARE_VM_GET_PAGE_PROT
150