xref: /linux/arch/nios2/mm/init.c (revision 4359a011e259a4608afc7fb3635370c9d4ba5943)
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 
30 #include <asm/setup.h>
31 #include <asm/page.h>
32 #include <asm/sections.h>
33 #include <asm/tlb.h>
34 #include <asm/mmu_context.h>
35 #include <asm/cpuinfo.h>
36 #include <asm/processor.h>
37 
38 pgd_t *pgd_current;
39 
40 /*
41  * paging_init() continues the virtual memory environment setup which
42  * was begun by the code in arch/head.S.
43  * The parameters are pointers to where to stick the starting and ending
44  * addresses of available kernel virtual memory.
45  */
46 void __init paging_init(void)
47 {
48 	unsigned long max_zone_pfn[MAX_NR_ZONES] = { 0 };
49 
50 	pagetable_init();
51 	pgd_current = swapper_pg_dir;
52 
53 	max_zone_pfn[ZONE_NORMAL] = max_mapnr;
54 
55 	/* pass the memory from the bootmem allocator to the main allocator */
56 	free_area_init(max_zone_pfn);
57 
58 	flush_dcache_range((unsigned long)empty_zero_page,
59 			(unsigned long)empty_zero_page + PAGE_SIZE);
60 }
61 
62 void __init mem_init(void)
63 {
64 	unsigned long end_mem   = memory_end; /* this must not include
65 						kernel stack at top */
66 
67 	pr_debug("mem_init: start=%lx, end=%lx\n", memory_start, memory_end);
68 
69 	end_mem &= PAGE_MASK;
70 	high_memory = __va(end_mem);
71 
72 	/* this will put all memory onto the freelists */
73 	memblock_free_all();
74 }
75 
76 void __init mmu_init(void)
77 {
78 	flush_tlb_all();
79 }
80 
81 pgd_t swapper_pg_dir[PTRS_PER_PGD] __aligned(PAGE_SIZE);
82 pte_t invalid_pte_table[PTRS_PER_PTE] __aligned(PAGE_SIZE);
83 static struct page *kuser_page[1];
84 
85 static int alloc_kuser_page(void)
86 {
87 	extern char __kuser_helper_start[], __kuser_helper_end[];
88 	int kuser_sz = __kuser_helper_end - __kuser_helper_start;
89 	unsigned long vpage;
90 
91 	vpage = get_zeroed_page(GFP_ATOMIC);
92 	if (!vpage)
93 		return -ENOMEM;
94 
95 	/* Copy kuser helpers */
96 	memcpy((void *)vpage, __kuser_helper_start, kuser_sz);
97 
98 	flush_icache_range(vpage, vpage + KUSER_SIZE);
99 	kuser_page[0] = virt_to_page(vpage);
100 
101 	return 0;
102 }
103 arch_initcall(alloc_kuser_page);
104 
105 int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
106 {
107 	struct mm_struct *mm = current->mm;
108 	int ret;
109 
110 	mmap_write_lock(mm);
111 
112 	/* Map kuser helpers to user space address */
113 	ret = install_special_mapping(mm, KUSER_BASE, KUSER_SIZE,
114 				      VM_READ | VM_EXEC | VM_MAYREAD |
115 				      VM_MAYEXEC, kuser_page);
116 
117 	mmap_write_unlock(mm);
118 
119 	return ret;
120 }
121 
122 const char *arch_vma_name(struct vm_area_struct *vma)
123 {
124 	return (vma->vm_start == KUSER_BASE) ? "[kuser]" : NULL;
125 }
126 
127 static const pgprot_t protection_map[16] = {
128 	[VM_NONE]					= MKP(0, 0, 0),
129 	[VM_READ]					= MKP(0, 0, 1),
130 	[VM_WRITE]					= MKP(0, 0, 0),
131 	[VM_WRITE | VM_READ]				= MKP(0, 0, 1),
132 	[VM_EXEC]					= MKP(1, 0, 0),
133 	[VM_EXEC | VM_READ]				= MKP(1, 0, 1),
134 	[VM_EXEC | VM_WRITE]				= MKP(1, 0, 0),
135 	[VM_EXEC | VM_WRITE | VM_READ]			= MKP(1, 0, 1),
136 	[VM_SHARED]					= MKP(0, 0, 0),
137 	[VM_SHARED | VM_READ]				= MKP(0, 0, 1),
138 	[VM_SHARED | VM_WRITE]				= MKP(0, 1, 0),
139 	[VM_SHARED | VM_WRITE | VM_READ]		= MKP(0, 1, 1),
140 	[VM_SHARED | VM_EXEC]				= MKP(1, 0, 0),
141 	[VM_SHARED | VM_EXEC | VM_READ]			= MKP(1, 0, 1),
142 	[VM_SHARED | VM_EXEC | VM_WRITE]		= MKP(1, 1, 0),
143 	[VM_SHARED | VM_EXEC | VM_WRITE | VM_READ]	= MKP(1, 1, 1)
144 };
145 DECLARE_VM_GET_PAGE_PROT
146