write in 30M

hc

2024-02-20 ea08eeccae9297f7aabd2ef7f0c2517ac4549acc

 kernel/arch/arc/kernel/fpu.c
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@@ -1,15 +1,14 @@
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+// SPDX-License-Identifier: GPL-2.0-only
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 /*
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  * fpu.c - save/restore of Floating Point Unit Registers on task switch
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  *
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  * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
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- *
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- * This program is free software; you can redistribute it and/or modify
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- * it under the terms of the GNU General Public License version 2 as
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- * published by the Free Software Foundation.
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  */
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 #include <linux/sched.h>
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-#include <asm/switch_to.h>
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+#include <asm/fpu.h>
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+
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+#ifdef CONFIG_ISA_ARCOMPACT
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 /*
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  * To save/restore FPU regs, simplest scheme would use LR/SR insns.
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@@ -53,3 +52,31 @@
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 		: "r" (zero), "r" (*(readfrom + 3)), "r" (*(readfrom + 2))
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 	);
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 }
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+
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+#else
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+
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+void fpu_init_task(struct pt_regs *regs)
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+{
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+	const unsigned int fwe = 0x80000000;
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+
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+	/* default rounding mode */
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+	write_aux_reg(ARC_REG_FPU_CTRL, 0x100);
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+
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+	/* Initialize to zero: setting requires FWE be set */
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+	write_aux_reg(ARC_REG_FPU_STATUS, fwe);
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+}
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+
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+void fpu_save_restore(struct task_struct *prev, struct task_struct *next)
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+{
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+	struct arc_fpu *save = &prev->thread.fpu;
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+	struct arc_fpu *restore = &next->thread.fpu;
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+	const unsigned int fwe = 0x80000000;
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+
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+	save->ctrl = read_aux_reg(ARC_REG_FPU_CTRL);
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+	save->status = read_aux_reg(ARC_REG_FPU_STATUS);
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+
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+	write_aux_reg(ARC_REG_FPU_CTRL, restore->ctrl);
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+	write_aux_reg(ARC_REG_FPU_STATUS, (fwe | restore->status));
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+}
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+
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+#endif