xref: /linux/arch/nios2/mm/init.c (revision 80d443e8876602be2c130f79c4de81e12e2a700d)
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/bootmem.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/pgtable.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  */
47 void __init paging_init(void)
48 {
49 	unsigned long zones_size[MAX_NR_ZONES];
50 
51 	memset(zones_size, 0, sizeof(zones_size));
52 
53 	pagetable_init();
54 	pgd_current = swapper_pg_dir;
55 
56 	zones_size[ZONE_NORMAL] = max_mapnr;
57 
58 	/* pass the memory from the bootmem allocator to the main allocator */
59 	free_area_init(zones_size);
60 
61 	flush_dcache_range((unsigned long)empty_zero_page,
62 			(unsigned long)empty_zero_page + PAGE_SIZE);
63 }
64 
65 void __init mem_init(void)
66 {
67 	unsigned long end_mem   = memory_end; /* this must not include
68 						kernel stack at top */
69 
70 	pr_debug("mem_init: start=%lx, end=%lx\n", memory_start, memory_end);
71 
72 	end_mem &= PAGE_MASK;
73 	high_memory = __va(end_mem);
74 
75 	/* this will put all memory onto the freelists */
76 	free_all_bootmem();
77 	mem_init_print_info(NULL);
78 }
79 
80 void __init mmu_init(void)
81 {
82 	flush_tlb_all();
83 }
84 
85 #ifdef CONFIG_BLK_DEV_INITRD
86 void __init free_initrd_mem(unsigned long start, unsigned long end)
87 {
88 	free_reserved_area((void *)start, (void *)end, -1, "initrd");
89 }
90 #endif
91 
92 void __ref free_initmem(void)
93 {
94 	free_initmem_default(-1);
95 }
96 
97 #define __page_aligned(order) __aligned(PAGE_SIZE << (order))
98 pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned(PGD_ORDER);
99 pte_t invalid_pte_table[PTRS_PER_PTE] __page_aligned(PTE_ORDER);
100 static struct page *kuser_page[1];
101 
102 static int alloc_kuser_page(void)
103 {
104 	extern char __kuser_helper_start[], __kuser_helper_end[];
105 	int kuser_sz = __kuser_helper_end - __kuser_helper_start;
106 	unsigned long vpage;
107 
108 	vpage = get_zeroed_page(GFP_ATOMIC);
109 	if (!vpage)
110 		return -ENOMEM;
111 
112 	/* Copy kuser helpers */
113 	memcpy((void *)vpage, __kuser_helper_start, kuser_sz);
114 
115 	flush_icache_range(vpage, vpage + KUSER_SIZE);
116 	kuser_page[0] = virt_to_page(vpage);
117 
118 	return 0;
119 }
120 arch_initcall(alloc_kuser_page);
121 
122 int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
123 {
124 	struct mm_struct *mm = current->mm;
125 	int ret;
126 
127 	down_write(&mm->mmap_sem);
128 
129 	/* Map kuser helpers to user space address */
130 	ret = install_special_mapping(mm, KUSER_BASE, KUSER_SIZE,
131 				      VM_READ | VM_EXEC | VM_MAYREAD |
132 				      VM_MAYEXEC, kuser_page);
133 
134 	up_write(&mm->mmap_sem);
135 
136 	return ret;
137 }
138 
139 const char *arch_vma_name(struct vm_area_struct *vma)
140 {
141 	return (vma->vm_start == KUSER_BASE) ? "[kuser]" : NULL;
142 }
143