1 /*
2 * Copyright (C) 2013 Altera Corporation
3 * Copyright (C) 2010 Tobias Klauser <tklauser@distanz.ch>
4 * Copyright (C) 2009 Wind River Systems Inc
5 * Implemented by fredrik.markstrom@gmail.com and ivarholmqvist@gmail.com
6 * Copyright (C) 2004 Microtronix Datacom Ltd
7 *
8 * based on arch/m68k/mm/init.c
9 *
10 * This file is subject to the terms and conditions of the GNU General Public
11 * License. See the file "COPYING" in the main directory of this archive
12 * for more details.
13 */
14
15 #include <linux/signal.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/ptrace.h>
22 #include <linux/mman.h>
23 #include <linux/mm.h>
24 #include <linux/init.h>
25 #include <linux/pagemap.h>
26 #include <linux/memblock.h>
27 #include <linux/slab.h>
28 #include <linux/binfmts.h>
29 #include <linux/execmem.h>
30
31 #include <asm/setup.h>
32 #include <asm/page.h>
33 #include <asm/sections.h>
34 #include <asm/tlb.h>
35 #include <asm/mmu_context.h>
36 #include <asm/cpuinfo.h>
37 #include <asm/processor.h>
38
39 pgd_t *pgd_current;
40
41 /*
42 * paging_init() continues the virtual memory environment setup which
43 * was begun by the code in arch/head.S.
44 * The parameters are pointers to where to stick the starting and ending
45 * addresses of available kernel virtual memory.
46 */
paging_init(void)47 void __init paging_init(void)
48 {
49 unsigned long max_zone_pfn[MAX_NR_ZONES] = { 0 };
50
51 pagetable_init();
52 pgd_current = swapper_pg_dir;
53
54 max_zone_pfn[ZONE_NORMAL] = max_low_pfn;
55
56 /* pass the memory from the bootmem allocator to the main allocator */
57 free_area_init(max_zone_pfn);
58
59 flush_dcache_range((unsigned long)empty_zero_page,
60 (unsigned long)empty_zero_page + PAGE_SIZE);
61 }
62
mmu_init(void)63 void __init mmu_init(void)
64 {
65 flush_tlb_all();
66 }
67
68 pgd_t swapper_pg_dir[PTRS_PER_PGD] __aligned(PAGE_SIZE);
69 pte_t invalid_pte_table[PTRS_PER_PTE] __aligned(PAGE_SIZE);
70 static struct page *kuser_page[1];
71 static struct vm_special_mapping vdso_mapping = {
72 .name = "[vdso]",
73 .pages = kuser_page,
74 };
75
alloc_kuser_page(void)76 static int alloc_kuser_page(void)
77 {
78 extern char __kuser_helper_start[], __kuser_helper_end[];
79 int kuser_sz = __kuser_helper_end - __kuser_helper_start;
80 unsigned long vpage;
81
82 vpage = get_zeroed_page(GFP_ATOMIC);
83 if (!vpage)
84 return -ENOMEM;
85
86 /* Copy kuser helpers */
87 memcpy((void *)vpage, __kuser_helper_start, kuser_sz);
88
89 flush_icache_range(vpage, vpage + KUSER_SIZE);
90 kuser_page[0] = virt_to_page(vpage);
91
92 return 0;
93 }
94 arch_initcall(alloc_kuser_page);
95
arch_setup_additional_pages(struct linux_binprm * bprm,int uses_interp)96 int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
97 {
98 struct mm_struct *mm = current->mm;
99 struct vm_area_struct *vma;
100
101 mmap_write_lock(mm);
102
103 /* Map kuser helpers to user space address */
104 vma = _install_special_mapping(mm, KUSER_BASE, KUSER_SIZE,
105 VM_READ | VM_EXEC | VM_MAYREAD |
106 VM_MAYEXEC, &vdso_mapping);
107
108 mmap_write_unlock(mm);
109
110 return IS_ERR(vma) ? PTR_ERR(vma) : 0;
111 }
112
arch_vma_name(struct vm_area_struct * vma)113 const char *arch_vma_name(struct vm_area_struct *vma)
114 {
115 return (vma->vm_start == KUSER_BASE) ? "[kuser]" : NULL;
116 }
117
118 static const pgprot_t protection_map[16] = {
119 [VM_NONE] = MKP(0, 0, 0),
120 [VM_READ] = MKP(0, 0, 1),
121 [VM_WRITE] = MKP(0, 0, 0),
122 [VM_WRITE | VM_READ] = MKP(0, 0, 1),
123 [VM_EXEC] = MKP(1, 0, 0),
124 [VM_EXEC | VM_READ] = MKP(1, 0, 1),
125 [VM_EXEC | VM_WRITE] = MKP(1, 0, 0),
126 [VM_EXEC | VM_WRITE | VM_READ] = MKP(1, 0, 1),
127 [VM_SHARED] = MKP(0, 0, 0),
128 [VM_SHARED | VM_READ] = MKP(0, 0, 1),
129 [VM_SHARED | VM_WRITE] = MKP(0, 1, 0),
130 [VM_SHARED | VM_WRITE | VM_READ] = MKP(0, 1, 1),
131 [VM_SHARED | VM_EXEC] = MKP(1, 0, 0),
132 [VM_SHARED | VM_EXEC | VM_READ] = MKP(1, 0, 1),
133 [VM_SHARED | VM_EXEC | VM_WRITE] = MKP(1, 1, 0),
134 [VM_SHARED | VM_EXEC | VM_WRITE | VM_READ] = MKP(1, 1, 1)
135 };
136 DECLARE_VM_GET_PAGE_PROT
137
138 #ifdef CONFIG_EXECMEM
139 static struct execmem_info execmem_info __ro_after_init;
140
execmem_arch_setup(void)141 struct execmem_info __init *execmem_arch_setup(void)
142 {
143 execmem_info = (struct execmem_info){
144 .ranges = {
145 [EXECMEM_DEFAULT] = {
146 .start = MODULES_VADDR,
147 .end = MODULES_END,
148 .pgprot = PAGE_KERNEL_EXEC,
149 .alignment = 1,
150 },
151 },
152 };
153
154 return &execmem_info;
155 }
156 #endif /* CONFIG_EXECMEM */
157