64 lines
1.5 KiB
C
64 lines
1.5 KiB
C
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/*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file "COPYING" in the main directory of this archive
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* for more details.
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*
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* Copyright (C) 2014 Lemote Corporation.
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* written by Huacai Chen <chenhc@lemote.com>
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*
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* based on arch/mips/cavium-octeon/cpu.c
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* Copyright (C) 2009 Wind River Systems,
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* written by Ralf Baechle <ralf@linux-mips.org>
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*/
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#include <linux/init.h>
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#include <linux/sched.h>
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#include <linux/notifier.h>
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#include <asm/fpu.h>
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#include <asm/cop2.h>
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#include <asm/current.h>
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#include <asm/mipsregs.h>
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static int loongson_cu2_call(struct notifier_block *nfb, unsigned long action,
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void *data)
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{
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int fpu_owned;
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int fr = !test_thread_flag(TIF_32BIT_FPREGS);
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switch (action) {
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case CU2_EXCEPTION:
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preempt_disable();
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fpu_owned = __is_fpu_owner();
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if (!fr)
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set_c0_status(ST0_CU1 | ST0_CU2);
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else
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set_c0_status(ST0_CU1 | ST0_CU2 | ST0_FR);
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enable_fpu_hazard();
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KSTK_STATUS(current) |= (ST0_CU1 | ST0_CU2);
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if (fr)
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KSTK_STATUS(current) |= ST0_FR;
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else
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KSTK_STATUS(current) &= ~ST0_FR;
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/* If FPU is owned, we needn't init or restore fp */
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if (!fpu_owned) {
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set_thread_flag(TIF_USEDFPU);
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if (!used_math()) {
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_init_fpu();
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set_used_math();
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} else
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_restore_fp(current);
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}
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preempt_enable();
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return NOTIFY_STOP; /* Don't call default notifier */
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}
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return NOTIFY_OK; /* Let default notifier send signals */
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}
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static int __init loongson_cu2_setup(void)
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{
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return cu2_notifier(loongson_cu2_call, 0);
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}
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early_initcall(loongson_cu2_setup);
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