tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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
38pgd_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 */
46void __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
62void __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
76void __init mmu_init(void)
77{
78 flush_tlb_all();
79}
80
81pgd_t swapper_pg_dir[PTRS_PER_PGD] __aligned(PAGE_SIZE);
82pte_t invalid_pte_table[PTRS_PER_PTE] __aligned(PAGE_SIZE);
83static struct page *kuser_page[1];
84
85static 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}
103arch_initcall(alloc_kuser_page);
104
105int 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
122const char *arch_vma_name(struct vm_area_struct *vma)
123{
124 return (vma->vm_start == KUSER_BASE) ? "[kuser]" : NULL;
125}
126
127static 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};
145DECLARE_VM_GET_PAGE_PROT