1 | // SPDX-License-Identifier: GPL-2.0 |
2 | #include <linux/mm_types.h> |
3 | #include <linux/rbtree.h> |
4 | #include <linux/rwsem.h> |
5 | #include <linux/spinlock.h> |
6 | #include <linux/list.h> |
7 | #include <linux/cpumask.h> |
8 | |
9 | #include <linux/atomic.h> |
10 | #include <linux/user_namespace.h> |
11 | #include <asm/pgtable.h> |
12 | #include <asm/mmu.h> |
13 | |
14 | #ifndef INIT_MM_CONTEXT |
15 | #define INIT_MM_CONTEXT(name) |
16 | #endif |
17 | |
18 | /* |
19 | * For dynamically allocated mm_structs, there is a dynamically sized cpumask |
20 | * at the end of the structure, the size of which depends on the maximum CPU |
21 | * number the system can see. That way we allocate only as much memory for |
22 | * mm_cpumask() as needed for the hundreds, or thousands of processes that |
23 | * a system typically runs. |
24 | * |
25 | * Since there is only one init_mm in the entire system, keep it simple |
26 | * and size this cpu_bitmask to NR_CPUS. |
27 | */ |
28 | struct mm_struct init_mm = { |
29 | .mm_rb = RB_ROOT, |
30 | .pgd = swapper_pg_dir, |
31 | .mm_users = ATOMIC_INIT(2), |
32 | .mm_count = ATOMIC_INIT(1), |
33 | .mmap_sem = __RWSEM_INITIALIZER(init_mm.mmap_sem), |
34 | .page_table_lock = __SPIN_LOCK_UNLOCKED(init_mm.page_table_lock), |
35 | .arg_lock = __SPIN_LOCK_UNLOCKED(init_mm.arg_lock), |
36 | .mmlist = LIST_HEAD_INIT(init_mm.mmlist), |
37 | .user_ns = &init_user_ns, |
38 | .cpu_bitmap = { [BITS_TO_LONGS(NR_CPUS)] = 0}, |
39 | INIT_MM_CONTEXT(init_mm) |
40 | }; |
41 | |