1#include <linux/sched.h>
 
 
 
 2#include <linux/slab.h>
 3#include <asm/processor.h>
 4#include <asm/fpu.h>
 5#include <asm/traps.h>
 
 6
 7int init_fpu(struct task_struct *tsk)
 8{
 9	if (tsk_used_math(tsk)) {
10		if ((boot_cpu_data.flags & CPU_HAS_FPU) && tsk == current)
11			unlazy_fpu(tsk, task_pt_regs(tsk));
12		return 0;
13	}
14
15	/*
16	 * Memory allocation at the first usage of the FPU and other state.
17	 */
18	if (!tsk->thread.xstate) {
19		tsk->thread.xstate = kmem_cache_alloc(task_xstate_cachep,
20						      GFP_KERNEL);
21		if (!tsk->thread.xstate)
22			return -ENOMEM;
23	}
24
25	if (boot_cpu_data.flags & CPU_HAS_FPU) {
26		struct sh_fpu_hard_struct *fp = &tsk->thread.xstate->hardfpu;
27		memset(fp, 0, xstate_size);
28		fp->fpscr = FPSCR_INIT;
29	} else {
30		struct sh_fpu_soft_struct *fp = &tsk->thread.xstate->softfpu;
31		memset(fp, 0, xstate_size);
32		fp->fpscr = FPSCR_INIT;
33	}
34
35	set_stopped_child_used_math(tsk);
36	return 0;
37}
38
39#ifdef CONFIG_SH_FPU
40void __fpu_state_restore(void)
41{
42	struct task_struct *tsk = current;
43
44	restore_fpu(tsk);
45
46	task_thread_info(tsk)->status |= TS_USEDFPU;
47	tsk->thread.fpu_counter++;
48}
49
50void fpu_state_restore(struct pt_regs *regs)
51{
52	struct task_struct *tsk = current;
53
54	if (unlikely(!user_mode(regs))) {
55		printk(KERN_ERR "BUG: FPU is used in kernel mode.\n");
56		BUG();
57		return;
58	}
59
60	if (!tsk_used_math(tsk)) {
61		local_irq_enable();
62		/*
63		 * does a slab alloc which can sleep
64		 */
65		if (init_fpu(tsk)) {
66			/*
67			 * ran out of memory!
68			 */
69			do_group_exit(SIGKILL);
70			return;
71		}
72		local_irq_disable();
73	}
74
75	grab_fpu(regs);
76
77	__fpu_state_restore();
78}
79
80BUILD_TRAP_HANDLER(fpu_state_restore)
81{
82	TRAP_HANDLER_DECL;
83
84	fpu_state_restore(regs);
85}
86#endif /* CONFIG_SH_FPU */

 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>
 7#include <asm/fpu.h>
 8#include <asm/traps.h>
 9#include <asm/ptrace.h>
10
11int init_fpu(struct task_struct *tsk)
12{
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));
16		return 0;
17	}
18
19	/*
20	 * Memory allocation at the first usage of the FPU and other state.
21	 */
22	if (!tsk->thread.xstate) {
23		tsk->thread.xstate = kmem_cache_alloc(task_xstate_cachep,
24						      GFP_KERNEL);
25		if (!tsk->thread.xstate)
26			return -ENOMEM;
27	}
28
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;
33	} else {
34		struct sh_fpu_soft_struct *fp = &tsk->thread.xstate->softfpu;
35		memset(fp, 0, xstate_size);
36		fp->fpscr = FPSCR_INIT;
37	}
38
39	set_stopped_child_used_math(tsk);
40	return 0;
41}
42
43#ifdef CONFIG_SH_FPU
44void __fpu_state_restore(void)
45{
46	struct task_struct *tsk = current;
47
48	restore_fpu(tsk);
49
50	task_thread_info(tsk)->status |= TS_USEDFPU;
51	tsk->thread.fpu_counter++;
52}
53
54void fpu_state_restore(struct pt_regs *regs)
55{
56	struct task_struct *tsk = current;
57
58	if (unlikely(!user_mode(regs))) {
59		printk(KERN_ERR "BUG: FPU is used in kernel mode.\n");
60		BUG();
61		return;
62	}
63
64	if (!tsk_used_math(tsk)) {
65		local_irq_enable();
66		/*
67		 * does a slab alloc which can sleep
68		 */
69		if (init_fpu(tsk)) {
70			/*
71			 * ran out of memory!
72			 */
73			do_group_exit(SIGKILL);
74			return;
75		}
76		local_irq_disable();
77	}
78
79	grab_fpu(regs);
80
81	__fpu_state_restore();
82}
83
84BUILD_TRAP_HANDLER(fpu_state_restore)
85{
86	TRAP_HANDLER_DECL;
87
88	fpu_state_restore(regs);
89}
90#endif /* CONFIG_SH_FPU */