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90 lines
1.8 KiB
90 lines
1.8 KiB
// SPDX-License-Identifier: GPL-2.0 |
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#include <linux/sched/signal.h> |
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#include <linux/sched/task.h> |
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#include <linux/sched/task_stack.h> |
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#include <linux/slab.h> |
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#include <asm/processor.h> |
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#include <asm/fpu.h> |
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#include <asm/traps.h> |
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#include <asm/ptrace.h> |
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int init_fpu(struct task_struct *tsk) |
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{ |
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if (tsk_used_math(tsk)) { |
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if ((boot_cpu_data.flags & CPU_HAS_FPU) && tsk == current) |
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unlazy_fpu(tsk, task_pt_regs(tsk)); |
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return 0; |
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} |
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/* |
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* Memory allocation at the first usage of the FPU and other state. |
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*/ |
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if (!tsk->thread.xstate) { |
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tsk->thread.xstate = kmem_cache_alloc(task_xstate_cachep, |
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GFP_KERNEL); |
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if (!tsk->thread.xstate) |
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return -ENOMEM; |
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} |
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if (boot_cpu_data.flags & CPU_HAS_FPU) { |
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struct sh_fpu_hard_struct *fp = &tsk->thread.xstate->hardfpu; |
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memset(fp, 0, xstate_size); |
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fp->fpscr = FPSCR_INIT; |
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} else { |
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struct sh_fpu_soft_struct *fp = &tsk->thread.xstate->softfpu; |
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memset(fp, 0, xstate_size); |
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fp->fpscr = FPSCR_INIT; |
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} |
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set_stopped_child_used_math(tsk); |
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return 0; |
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} |
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#ifdef CONFIG_SH_FPU |
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void __fpu_state_restore(void) |
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{ |
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struct task_struct *tsk = current; |
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restore_fpu(tsk); |
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task_thread_info(tsk)->status |= TS_USEDFPU; |
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tsk->thread.fpu_counter++; |
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} |
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void fpu_state_restore(struct pt_regs *regs) |
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{ |
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struct task_struct *tsk = current; |
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if (unlikely(!user_mode(regs))) { |
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printk(KERN_ERR "BUG: FPU is used in kernel mode.\n"); |
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BUG(); |
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return; |
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} |
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if (!tsk_used_math(tsk)) { |
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local_irq_enable(); |
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/* |
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* does a slab alloc which can sleep |
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*/ |
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if (init_fpu(tsk)) { |
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/* |
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* ran out of memory! |
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*/ |
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do_group_exit(SIGKILL); |
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return; |
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} |
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local_irq_disable(); |
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} |
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grab_fpu(regs); |
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__fpu_state_restore(); |
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} |
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BUILD_TRAP_HANDLER(fpu_state_restore) |
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{ |
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TRAP_HANDLER_DECL; |
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fpu_state_restore(regs); |
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} |
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#endif /* CONFIG_SH_FPU */
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