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
 39pgd_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 */
 47void __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_mapnr;
 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
 63void __init mem_init(void)
 64{
 65	unsigned long end_mem   = memory_end; /* this must not include
 66						kernel stack at top */
 67
 68	pr_debug("mem_init: start=%lx, end=%lx\n", memory_start, memory_end);
 69
 70	end_mem &= PAGE_MASK;
 71	high_memory = __va(end_mem);
 72
 73	/* this will put all memory onto the freelists */
 74	memblock_free_all();
 75}
 76
 77void __init mmu_init(void)
 78{
 79	flush_tlb_all();
 80}
 81
 82pgd_t swapper_pg_dir[PTRS_PER_PGD] __aligned(PAGE_SIZE);
 83pte_t invalid_pte_table[PTRS_PER_PTE] __aligned(PAGE_SIZE);
 84static struct page *kuser_page[1];
 85static struct vm_special_mapping vdso_mapping = {
 86	.name = "[vdso]",
 87	.pages = kuser_page,
 88};
 89
 90static int alloc_kuser_page(void)
 91{
 92	extern char __kuser_helper_start[], __kuser_helper_end[];
 93	int kuser_sz = __kuser_helper_end - __kuser_helper_start;
 94	unsigned long vpage;
 95
 96	vpage = get_zeroed_page(GFP_ATOMIC);
 97	if (!vpage)
 98		return -ENOMEM;
 99
100	/* Copy kuser helpers */
101	memcpy((void *)vpage, __kuser_helper_start, kuser_sz);
102
103	flush_icache_range(vpage, vpage + KUSER_SIZE);
104	kuser_page[0] = virt_to_page(vpage);
105
106	return 0;
107}
108arch_initcall(alloc_kuser_page);
109
110int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
111{
112	struct mm_struct *mm = current->mm;
113	struct vm_area_struct *vma;
114
115	mmap_write_lock(mm);
116
117	/* Map kuser helpers to user space address */
118	vma = _install_special_mapping(mm, KUSER_BASE, KUSER_SIZE,
119				      VM_READ | VM_EXEC | VM_MAYREAD |
120				      VM_MAYEXEC, &vdso_mapping);
121
122	mmap_write_unlock(mm);
123
124	return IS_ERR(vma) ? PTR_ERR(vma) : 0;
125}
126
127const char *arch_vma_name(struct vm_area_struct *vma)
128{
129	return (vma->vm_start == KUSER_BASE) ? "[kuser]" : NULL;
130}
131
132static const pgprot_t protection_map[16] = {
133	[VM_NONE]					= MKP(0, 0, 0),
134	[VM_READ]					= MKP(0, 0, 1),
135	[VM_WRITE]					= MKP(0, 0, 0),
136	[VM_WRITE | VM_READ]				= MKP(0, 0, 1),
137	[VM_EXEC]					= MKP(1, 0, 0),
138	[VM_EXEC | VM_READ]				= MKP(1, 0, 1),
139	[VM_EXEC | VM_WRITE]				= MKP(1, 0, 0),
140	[VM_EXEC | VM_WRITE | VM_READ]			= MKP(1, 0, 1),
141	[VM_SHARED]					= MKP(0, 0, 0),
142	[VM_SHARED | VM_READ]				= MKP(0, 0, 1),
143	[VM_SHARED | VM_WRITE]				= MKP(0, 1, 0),
144	[VM_SHARED | VM_WRITE | VM_READ]		= MKP(0, 1, 1),
145	[VM_SHARED | VM_EXEC]				= MKP(1, 0, 0),
146	[VM_SHARED | VM_EXEC | VM_READ]			= MKP(1, 0, 1),
147	[VM_SHARED | VM_EXEC | VM_WRITE]		= MKP(1, 1, 0),
148	[VM_SHARED | VM_EXEC | VM_WRITE | VM_READ]	= MKP(1, 1, 1)
149};
150DECLARE_VM_GET_PAGE_PROT
151
152#ifdef CONFIG_EXECMEM
153static struct execmem_info execmem_info __ro_after_init;
154
155struct execmem_info __init *execmem_arch_setup(void)
156{
157	execmem_info = (struct execmem_info){
158		.ranges = {
159			[EXECMEM_DEFAULT] = {
160				.start	= MODULES_VADDR,
161				.end	= MODULES_END,
162				.pgprot	= PAGE_KERNEL_EXEC,
163				.alignment = 1,
164			},
165		},
166	};
167
168	return &execmem_info;
169}
170#endif /* CONFIG_EXECMEM */