init-mm.c

 1// SPDX-License-Identifier: GPL-2.0
 2#include <linux/mm_types.h>
 3#include <linux/maple_tree.h>
 4#include <linux/rwsem.h>
 5#include <linux/spinlock.h>
 6#include <linux/list.h>
 7#include <linux/cpumask.h>
 8#include <linux/mman.h>
 9#include <linux/pgtable.h>
10
11#include <linux/atomic.h>
12#include <linux/user_namespace.h>
13#include <linux/iommu.h>
14#include <asm/mmu.h>
15
16#ifndef INIT_MM_CONTEXT
17#define INIT_MM_CONTEXT(name)
18#endif
19
20const struct vm_operations_struct vma_dummy_vm_ops;
21
22/*
23 * For dynamically allocated mm_structs, there is a dynamically sized cpumask
24 * at the end of the structure, the size of which depends on the maximum CPU
25 * number the system can see. That way we allocate only as much memory for
26 * mm_cpumask() as needed for the hundreds, or thousands of processes that
27 * a system typically runs.
28 *
29 * Since there is only one init_mm in the entire system, keep it simple
30 * and size this cpu_bitmask to NR_CPUS.
31 */
32struct mm_struct init_mm = {
33	.mm_mt		= MTREE_INIT_EXT(mm_mt, MM_MT_FLAGS, init_mm.mmap_lock),
34	.pgd		= swapper_pg_dir,
35	.mm_users	= ATOMIC_INIT(2),
36	.mm_count	= ATOMIC_INIT(1),
37	.write_protect_seq = SEQCNT_ZERO(init_mm.write_protect_seq),
38	MMAP_LOCK_INITIALIZER(init_mm)
39	.page_table_lock =  __SPIN_LOCK_UNLOCKED(init_mm.page_table_lock),
40	.arg_lock	=  __SPIN_LOCK_UNLOCKED(init_mm.arg_lock),
41	.mmlist		= LIST_HEAD_INIT(init_mm.mmlist),
42#ifdef CONFIG_PER_VMA_LOCK
43	.vma_writer_wait = __RCUWAIT_INITIALIZER(init_mm.vma_writer_wait),
44	.mm_lock_seq	= SEQCNT_ZERO(init_mm.mm_lock_seq),
45#endif
46	.user_ns	= &init_user_ns,
47#ifdef CONFIG_SCHED_MM_CID
48	.mm_cid.lock = __RAW_SPIN_LOCK_UNLOCKED(init_mm.mm_cid.lock),
49#endif
50	.flexible_array	= MM_STRUCT_FLEXIBLE_ARRAY_INIT,
51	INIT_MM_CONTEXT(init_mm)
52};
53
54void setup_initial_init_mm(void *start_code, void *end_code,
55			   void *end_data, void *brk)
56{
57	init_mm.start_code = (unsigned long)start_code;
58	init_mm.end_code = (unsigned long)end_code;
59	init_mm.end_data = (unsigned long)end_data;
60	init_mm.brk = (unsigned long)brk;
61}