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