[PATCH v2 12/17] riscv: Create xtheadvector file

Charlie Jenkins
2024-04-16T04:13:52Z

These definitions didn't fit anywhere nicely, so create a new file to
house various xtheadvector instruction encodings.

Co-developed-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Charlie Jenkins <charlie@rivosinc.com>
---
arch/riscv/include/asm/xtheadvector.h | 25 +++++++++++++++++++++++++
1 file changed, 25 insertions(+)

diff --git a/arch/riscv/include/asm/xtheadvector.h b/arch/riscv/include/asm/xtheadvector.h
new file mode 100644
index 000000000000..348263ea164c
--- /dev/null
+++ b/arch/riscv/include/asm/xtheadvector.h
@@ -0,0 +1,25 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+/*
+ * Vector 0.7.1 as used for example on T-Head Xuantie cores, uses an older
+ * encoding for vsetvli (ta, ma vs. d1), so provide an instruction for
+ * vsetvli t4, x0, e8, m8, d1
+ */
+#define THEAD_VSETVLI_T4X0E8M8D1 ".long 0x00307ed7\n\t"
+#define THEAD_VSETVLI_X0X0E8M8D1 ".long 0x00307057\n\t"
+
+/*
+ * While in theory, the vector-0.7.1 vsb.v and vlb.v result in the same
+ * encoding as the standard vse8.v and vle8.v, compilers seem to optimize
+ * the call resulting in a different encoding and then using a value for
+ * the "mop" field that is not part of vector-0.7.1
+ * So encode specific variants for vstate_save and _restore.
+ */
+#define THEAD_VSB_V_V0T0 ".long 0x02028027\n\t"
+#define THEAD_VSB_V_V8T0 ".long 0x02028427\n\t"
+#define THEAD_VSB_V_V16T0 ".long 0x02028827\n\t"
+#define THEAD_VSB_V_V24T0 ".long 0x02028c27\n\t"
+#define THEAD_VLB_V_V0T0 ".long 0x012028007\n\t"
+#define THEAD_VLB_V_V8T0 ".long 0x012028407\n\t"
+#define THEAD_VLB_V_V16T0 ".long 0x012028807\n\t"
+#define THEAD_VLB_V_V24T0 ".long 0x012028c07\n\t"