1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/sched/signal.h>
3 #include <linux/sched/task.h>
4 #include <linux/sched/task_stack.h>
5 #include <linux/slab.h>
6 #include <asm/processor.h>
9 #include <asm/ptrace.h>
11 int init_fpu(struct task_struct *tsk)
13 if (tsk_used_math(tsk)) {
14 if ((boot_cpu_data.flags & CPU_HAS_FPU) && tsk == current)
15 unlazy_fpu(tsk, task_pt_regs(tsk));
20 * Memory allocation at the first usage of the FPU and other state.
22 if (!tsk->thread.xstate) {
23 tsk->thread.xstate = kmem_cache_alloc(task_xstate_cachep,
25 if (!tsk->thread.xstate)
29 if (boot_cpu_data.flags & CPU_HAS_FPU) {
30 struct sh_fpu_hard_struct *fp = &tsk->thread.xstate->hardfpu;
31 memset(fp, 0, xstate_size);
32 fp->fpscr = FPSCR_INIT;
34 struct sh_fpu_soft_struct *fp = &tsk->thread.xstate->softfpu;
35 memset(fp, 0, xstate_size);
36 fp->fpscr = FPSCR_INIT;
39 set_stopped_child_used_math(tsk);
44 void __fpu_state_restore(void)
46 struct task_struct *tsk = current;
50 task_thread_info(tsk)->status |= TS_USEDFPU;
51 tsk->thread.fpu_counter++;
54 void fpu_state_restore(struct pt_regs *regs)
56 struct task_struct *tsk = current;
58 if (unlikely(!user_mode(regs))) {
59 printk(KERN_ERR "BUG: FPU is used in kernel mode.\n");
64 if (!tsk_used_math(tsk)) {
67 * does a slab alloc which can sleep
83 __fpu_state_restore();
86 BUILD_TRAP_HANDLER(fpu_state_restore)
90 fpu_state_restore(regs);
92 #endif /* CONFIG_SH_FPU */