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 #include <linux/mman.h> 9 #include <linux/pgtable.h> 10 11 #include <linux/atomic.h> 12 #include <linux/user_namespace.h> 13 #include <asm/mmu.h> 14 15 #ifndef INIT_MM_CONTEXT 16 #define INIT_MM_CONTEXT(name) 17 #endif 18 19 /* 20 * For dynamically allocated mm_structs, there is a dynamically sized cpumask 21 * at the end of the structure, the size of which depends on the maximum CPU 22 * number the system can see. That way we allocate only as much memory for 23 * mm_cpumask() as needed for the hundreds, or thousands of processes that 24 * a system typically runs. 25 * 26 * Since there is only one init_mm in the entire system, keep it simple 27 * and size this cpu_bitmask to NR_CPUS. 28 */ 29 struct mm_struct init_mm = { 30 .mm_rb = RB_ROOT, 31 .pgd = swapper_pg_dir, 32 .mm_users = ATOMIC_INIT(2), 33 .mm_count = ATOMIC_INIT(1), 34 .write_protect_seq = SEQCNT_ZERO(init_mm.write_protect_seq), 35 MMAP_LOCK_INITIALIZER(init_mm) 36 .page_table_lock = __SPIN_LOCK_UNLOCKED(init_mm.page_table_lock), 37 .arg_lock = __SPIN_LOCK_UNLOCKED(init_mm.arg_lock), 38 .mmlist = LIST_HEAD_INIT(init_mm.mmlist), 39 .user_ns = &init_user_ns, 40 .cpu_bitmap = CPU_BITS_NONE, 41 INIT_MM_CONTEXT(init_mm) 42 }; 43