kselftest/arm64: Add manual encodings for SME instructions

As for the kernel so that we don't have ambitious toolchain requirements
to build the tests manually encode some of the SVE instructions.
Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Shuah Khan <skhan@linuxfoundation.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20220419112247.711548-29-broonie@kernel.orgSigned-off-by: Catalin Marinas <catalin.marinas@arm.com>

tools/testing/selftests/arm64/fp/sme-inst.h

+// SPDX-License-Identifier: GPL-2.0-only
+// Copyright (C) 2021-2 ARM Limited.
+// Original author: Mark Brown <broonie@kernel.org>
+
+#ifndef SME_INST_H
+#define SME_INST_H
+
+/*
+ * RDSVL X\nx, #\imm
+ */
+.macro rdsvl nx, imm
+	.inst	0x4bf5800			\
+		| (\imm << 5)			\
+		| (\nx)
+.endm
+
+.macro smstop
+	msr	S0_3_C4_C6_3, xzr
+.endm
+
+.macro smstart_za
+	msr	S0_3_C4_C5_3, xzr
+.endm
+
+.macro smstart_sm
+	msr	S0_3_C4_C3_3, xzr
+.endm
+
+/*
+ * LDR (vector to ZA array):
+ *	LDR ZA[\nw, #\offset], [X\nxbase, #\offset, MUL VL]
+ */
+.macro _ldr_za nw, nxbase, offset=0
+	.inst	0xe1000000			\
+		| (((\nw) & 3) << 13)		\
+		| ((\nxbase) << 5)		\
+		| ((\offset) & 7)
+.endm
+
+/*
+ * STR (vector from ZA array):
+ *	STR ZA[\nw, #\offset], [X\nxbase, #\offset, MUL VL]
+ */
+.macro _str_za nw, nxbase, offset=0
+	.inst	0xe1200000			\
+		| (((\nw) & 3) << 13)		\
+		| ((\nxbase) << 5)		\
+		| ((\offset) & 7)
+.endm
+
+#endif