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