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-rw-r--r--arch/loongarch/kernel/fpu.S251
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diff --git a/arch/loongarch/kernel/fpu.S b/arch/loongarch/kernel/fpu.S
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+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Author: Lu Zeng <zenglu@loongson.cn>
+ * Pei Huang <huangpei@loongson.cn>
+ * Huacai Chen <chenhuacai@loongson.cn>
+ *
+ * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
+ */
+#include <asm/asm.h>
+#include <asm/asmmacro.h>
+#include <asm/asm-offsets.h>
+#include <asm/errno.h>
+#include <asm/export.h>
+#include <asm/fpregdef.h>
+#include <asm/loongarch.h>
+#include <asm/regdef.h>
+
+#define FPU_REG_WIDTH 8
+#define LSX_REG_WIDTH 16
+#define LASX_REG_WIDTH 32
+
+ .macro EX insn, reg, src, offs
+.ex\@: \insn \reg, \src, \offs
+ .section __ex_table,"a"
+ PTR .ex\@, fault
+ .previous
+ .endm
+
+ .macro sc_save_fp base
+ EX fst.d $f0, \base, (0 * FPU_REG_WIDTH)
+ EX fst.d $f1, \base, (1 * FPU_REG_WIDTH)
+ EX fst.d $f2, \base, (2 * FPU_REG_WIDTH)
+ EX fst.d $f3, \base, (3 * FPU_REG_WIDTH)
+ EX fst.d $f4, \base, (4 * FPU_REG_WIDTH)
+ EX fst.d $f5, \base, (5 * FPU_REG_WIDTH)
+ EX fst.d $f6, \base, (6 * FPU_REG_WIDTH)
+ EX fst.d $f7, \base, (7 * FPU_REG_WIDTH)
+ EX fst.d $f8, \base, (8 * FPU_REG_WIDTH)
+ EX fst.d $f9, \base, (9 * FPU_REG_WIDTH)
+ EX fst.d $f10, \base, (10 * FPU_REG_WIDTH)
+ EX fst.d $f11, \base, (11 * FPU_REG_WIDTH)
+ EX fst.d $f12, \base, (12 * FPU_REG_WIDTH)
+ EX fst.d $f13, \base, (13 * FPU_REG_WIDTH)
+ EX fst.d $f14, \base, (14 * FPU_REG_WIDTH)
+ EX fst.d $f15, \base, (15 * FPU_REG_WIDTH)
+ EX fst.d $f16, \base, (16 * FPU_REG_WIDTH)
+ EX fst.d $f17, \base, (17 * FPU_REG_WIDTH)
+ EX fst.d $f18, \base, (18 * FPU_REG_WIDTH)
+ EX fst.d $f19, \base, (19 * FPU_REG_WIDTH)
+ EX fst.d $f20, \base, (20 * FPU_REG_WIDTH)
+ EX fst.d $f21, \base, (21 * FPU_REG_WIDTH)
+ EX fst.d $f22, \base, (22 * FPU_REG_WIDTH)
+ EX fst.d $f23, \base, (23 * FPU_REG_WIDTH)
+ EX fst.d $f24, \base, (24 * FPU_REG_WIDTH)
+ EX fst.d $f25, \base, (25 * FPU_REG_WIDTH)
+ EX fst.d $f26, \base, (26 * FPU_REG_WIDTH)
+ EX fst.d $f27, \base, (27 * FPU_REG_WIDTH)
+ EX fst.d $f28, \base, (28 * FPU_REG_WIDTH)
+ EX fst.d $f29, \base, (29 * FPU_REG_WIDTH)
+ EX fst.d $f30, \base, (30 * FPU_REG_WIDTH)
+ EX fst.d $f31, \base, (31 * FPU_REG_WIDTH)
+ .endm
+
+ .macro sc_restore_fp base
+ EX fld.d $f0, \base, (0 * FPU_REG_WIDTH)
+ EX fld.d $f1, \base, (1 * FPU_REG_WIDTH)
+ EX fld.d $f2, \base, (2 * FPU_REG_WIDTH)
+ EX fld.d $f3, \base, (3 * FPU_REG_WIDTH)
+ EX fld.d $f4, \base, (4 * FPU_REG_WIDTH)
+ EX fld.d $f5, \base, (5 * FPU_REG_WIDTH)
+ EX fld.d $f6, \base, (6 * FPU_REG_WIDTH)
+ EX fld.d $f7, \base, (7 * FPU_REG_WIDTH)
+ EX fld.d $f8, \base, (8 * FPU_REG_WIDTH)
+ EX fld.d $f9, \base, (9 * FPU_REG_WIDTH)
+ EX fld.d $f10, \base, (10 * FPU_REG_WIDTH)
+ EX fld.d $f11, \base, (11 * FPU_REG_WIDTH)
+ EX fld.d $f12, \base, (12 * FPU_REG_WIDTH)
+ EX fld.d $f13, \base, (13 * FPU_REG_WIDTH)
+ EX fld.d $f14, \base, (14 * FPU_REG_WIDTH)
+ EX fld.d $f15, \base, (15 * FPU_REG_WIDTH)
+ EX fld.d $f16, \base, (16 * FPU_REG_WIDTH)
+ EX fld.d $f17, \base, (17 * FPU_REG_WIDTH)
+ EX fld.d $f18, \base, (18 * FPU_REG_WIDTH)
+ EX fld.d $f19, \base, (19 * FPU_REG_WIDTH)
+ EX fld.d $f20, \base, (20 * FPU_REG_WIDTH)
+ EX fld.d $f21, \base, (21 * FPU_REG_WIDTH)
+ EX fld.d $f22, \base, (22 * FPU_REG_WIDTH)
+ EX fld.d $f23, \base, (23 * FPU_REG_WIDTH)
+ EX fld.d $f24, \base, (24 * FPU_REG_WIDTH)
+ EX fld.d $f25, \base, (25 * FPU_REG_WIDTH)
+ EX fld.d $f26, \base, (26 * FPU_REG_WIDTH)
+ EX fld.d $f27, \base, (27 * FPU_REG_WIDTH)
+ EX fld.d $f28, \base, (28 * FPU_REG_WIDTH)
+ EX fld.d $f29, \base, (29 * FPU_REG_WIDTH)
+ EX fld.d $f30, \base, (30 * FPU_REG_WIDTH)
+ EX fld.d $f31, \base, (31 * FPU_REG_WIDTH)
+ .endm
+
+ .macro sc_save_fcc base, tmp0, tmp1
+ movcf2gr \tmp0, $fcc0
+ move \tmp1, \tmp0
+ movcf2gr \tmp0, $fcc1
+ bstrins.d \tmp1, \tmp0, 15, 8
+ movcf2gr \tmp0, $fcc2
+ bstrins.d \tmp1, \tmp0, 23, 16
+ movcf2gr \tmp0, $fcc3
+ bstrins.d \tmp1, \tmp0, 31, 24
+ movcf2gr \tmp0, $fcc4
+ bstrins.d \tmp1, \tmp0, 39, 32
+ movcf2gr \tmp0, $fcc5
+ bstrins.d \tmp1, \tmp0, 47, 40
+ movcf2gr \tmp0, $fcc6
+ bstrins.d \tmp1, \tmp0, 55, 48
+ movcf2gr \tmp0, $fcc7
+ bstrins.d \tmp1, \tmp0, 63, 56
+ EX st.d \tmp1, \base, 0
+ .endm
+
+ .macro sc_restore_fcc base, tmp0, tmp1
+ EX ld.d \tmp0, \base, 0
+ bstrpick.d \tmp1, \tmp0, 7, 0
+ movgr2cf $fcc0, \tmp1
+ bstrpick.d \tmp1, \tmp0, 15, 8
+ movgr2cf $fcc1, \tmp1
+ bstrpick.d \tmp1, \tmp0, 23, 16
+ movgr2cf $fcc2, \tmp1
+ bstrpick.d \tmp1, \tmp0, 31, 24
+ movgr2cf $fcc3, \tmp1
+ bstrpick.d \tmp1, \tmp0, 39, 32
+ movgr2cf $fcc4, \tmp1
+ bstrpick.d \tmp1, \tmp0, 47, 40
+ movgr2cf $fcc5, \tmp1
+ bstrpick.d \tmp1, \tmp0, 55, 48
+ movgr2cf $fcc6, \tmp1
+ bstrpick.d \tmp1, \tmp0, 63, 56
+ movgr2cf $fcc7, \tmp1
+ .endm
+
+ .macro sc_save_fcsr base, tmp0
+ movfcsr2gr \tmp0, fcsr0
+ EX st.w \tmp0, \base, 0
+ .endm
+
+ .macro sc_restore_fcsr base, tmp0
+ EX ld.w \tmp0, \base, 0
+ movgr2fcsr fcsr0, \tmp0
+ .endm
+
+/*
+ * Save a thread's fp context.
+ */
+SYM_FUNC_START(_save_fp)
+ fpu_save_csr a0 t1
+ fpu_save_double a0 t1 # clobbers t1
+ fpu_save_cc a0 t1 t2 # clobbers t1, t2
+ jr ra
+SYM_FUNC_END(_save_fp)
+EXPORT_SYMBOL(_save_fp)
+
+/*
+ * Restore a thread's fp context.
+ */
+SYM_FUNC_START(_restore_fp)
+ fpu_restore_double a0 t1 # clobbers t1
+ fpu_restore_csr a0 t1
+ fpu_restore_cc a0 t1 t2 # clobbers t1, t2
+ jr ra
+SYM_FUNC_END(_restore_fp)
+
+/*
+ * Load the FPU with signalling NANS. This bit pattern we're using has
+ * the property that no matter whether considered as single or as double
+ * precision represents signaling NANS.
+ *
+ * The value to initialize fcsr0 to comes in $a0.
+ */
+
+SYM_FUNC_START(_init_fpu)
+ li.w t1, CSR_EUEN_FPEN
+ csrxchg t1, t1, LOONGARCH_CSR_EUEN
+
+ movgr2fcsr fcsr0, a0
+
+ li.w t1, -1 # SNaN
+
+ movgr2fr.d $f0, t1
+ movgr2fr.d $f1, t1
+ movgr2fr.d $f2, t1
+ movgr2fr.d $f3, t1
+ movgr2fr.d $f4, t1
+ movgr2fr.d $f5, t1
+ movgr2fr.d $f6, t1
+ movgr2fr.d $f7, t1
+ movgr2fr.d $f8, t1
+ movgr2fr.d $f9, t1
+ movgr2fr.d $f10, t1
+ movgr2fr.d $f11, t1
+ movgr2fr.d $f12, t1
+ movgr2fr.d $f13, t1
+ movgr2fr.d $f14, t1
+ movgr2fr.d $f15, t1
+ movgr2fr.d $f16, t1
+ movgr2fr.d $f17, t1
+ movgr2fr.d $f18, t1
+ movgr2fr.d $f19, t1
+ movgr2fr.d $f20, t1
+ movgr2fr.d $f21, t1
+ movgr2fr.d $f22, t1
+ movgr2fr.d $f23, t1
+ movgr2fr.d $f24, t1
+ movgr2fr.d $f25, t1
+ movgr2fr.d $f26, t1
+ movgr2fr.d $f27, t1
+ movgr2fr.d $f28, t1
+ movgr2fr.d $f29, t1
+ movgr2fr.d $f30, t1
+ movgr2fr.d $f31, t1
+
+ jr ra
+SYM_FUNC_END(_init_fpu)
+
+/*
+ * a0: fpregs
+ * a1: fcc
+ * a2: fcsr
+ */
+SYM_FUNC_START(_save_fp_context)
+ sc_save_fcc a1 t1 t2
+ sc_save_fcsr a2 t1
+ sc_save_fp a0
+ li.w a0, 0 # success
+ jr ra
+SYM_FUNC_END(_save_fp_context)
+
+/*
+ * a0: fpregs
+ * a1: fcc
+ * a2: fcsr
+ */
+SYM_FUNC_START(_restore_fp_context)
+ sc_restore_fp a0
+ sc_restore_fcc a1 t1 t2
+ sc_restore_fcsr a2 t1
+ li.w a0, 0 # success
+ jr ra
+SYM_FUNC_END(_restore_fp_context)
+
+SYM_FUNC_START(fault)
+ li.w a0, -EFAULT # failure
+ jr ra
+SYM_FUNC_END(fault)