feat(d128): add support for FEAT_D128
This patch disables trapping to EL3 when the FEAT_D128
specific registers are accessed by setting the SCR_EL3.D128En bit.
If FEAT_D128 is implemented, then FEAT_SYSREG128 is implemented.
With FEAT_SYSREG128 certain system registers are treated as 128-bit,
so we should be context saving and restoring 128-bits instead of 64-bit
when FEAT_D128 is enabled.
FEAT_SYSREG128 adds support for MRRS and MSRR instruction which
helps us to read write to 128-bit system register.
Refer to Arm Architecture Manual for further details.
Change the FVP platform to default to handling this as a dynamic option
so the right decision can be made by the code at runtime.
Change-Id: I1a53db5eac29e56c8fbdcd4961ede3abfcb2411a
Signed-off-by: Jayanth Dodderi Chidanand <jayanthdodderi.chidanand@arm.com>
Signed-off-by: Govindraj Raja <govindraj.raja@arm.com>
diff --git a/include/lib/extensions/sysreg128.h b/include/lib/extensions/sysreg128.h
new file mode 100644
index 0000000..8854856
--- /dev/null
+++ b/include/lib/extensions/sysreg128.h
@@ -0,0 +1,36 @@
+/*
+ * Copyright (c) 2024, Arm Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef SYSREG128_H
+#define SYSREG128_H
+
+#ifndef __ASSEMBLER__
+
+#if ENABLE_FEAT_D128
+#include <stdint.h>
+
+typedef uint128_t sysreg_t;
+
+#define PAR_EL1_D128 (((sysreg_t)(1ULL)) << (64))
+
+#define _DECLARE_SYSREG128_READ_FUNC(_name) \
+uint128_t read_ ## _name(void);
+
+#define _DECLARE_SYSREG128_WRITE_FUNC(_name) \
+void write_ ## _name(uint128_t v);
+
+#define DECLARE_SYSREG128_RW_FUNCS(_name) \
+ _DECLARE_SYSREG128_READ_FUNC(_name) \
+ _DECLARE_SYSREG128_WRITE_FUNC(_name)
+#else
+
+typedef uint64_t sysreg_t;
+
+#endif /* ENABLE_FEAT_D128 */
+
+#endif /* __ASSEMBLER__ */
+
+#endif /* SYSREG128_H */