aarch64: Make cpu-features definitions not Linux-specific

These describe generic AArch64 CPU features, and are not tied to a
kernel-specific way of determining them. We can share them between
the Linux and Hurd AArch64 ports.

Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
Message-ID: <20240103171502.1358371-13-bugaevc@gmail.com>

2 files changed, 110 insertions, 0 deletions

diff --git a/sysdeps/aarch64/cpu-features.h b/sysdeps/aarch64/cpu-features.h
new file mode 100644
index 0000000000..77a782422a
--- /dev/null
+++ b/sysdeps/aarch64/cpu-features.h
@@ -0,0 +1,77 @@
+/* Initialize CPU feature data.  AArch64 version.
+   This file is part of the GNU C Library.
+   Copyright (C) 2017-2024 Free Software Foundation, Inc.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#ifndef _CPU_FEATURES_AARCH64_H
+#define _CPU_FEATURES_AARCH64_H
+
+#include <stdint.h>
+#include <stdbool.h>
+
+#define MIDR_PARTNUM_SHIFT	4
+#define MIDR_PARTNUM_MASK	(0xfff << MIDR_PARTNUM_SHIFT)
+#define MIDR_PARTNUM(midr)	\
+	(((midr) & MIDR_PARTNUM_MASK) >> MIDR_PARTNUM_SHIFT)
+#define MIDR_ARCHITECTURE_SHIFT	16
+#define MIDR_ARCHITECTURE_MASK	(0xf << MIDR_ARCHITECTURE_SHIFT)
+#define MIDR_ARCHITECTURE(midr)	\
+	(((midr) & MIDR_ARCHITECTURE_MASK) >> MIDR_ARCHITECTURE_SHIFT)
+#define MIDR_VARIANT_SHIFT	20
+#define MIDR_VARIANT_MASK	(0xf << MIDR_VARIANT_SHIFT)
+#define MIDR_VARIANT(midr)	\
+	(((midr) & MIDR_VARIANT_MASK) >> MIDR_VARIANT_SHIFT)
+#define MIDR_IMPLEMENTOR_SHIFT	24
+#define MIDR_IMPLEMENTOR_MASK	(0xff << MIDR_IMPLEMENTOR_SHIFT)
+#define MIDR_IMPLEMENTOR(midr)	\
+	(((midr) & MIDR_IMPLEMENTOR_MASK) >> MIDR_IMPLEMENTOR_SHIFT)
+
+#define IS_THUNDERX(midr) (MIDR_IMPLEMENTOR(midr) == 'C'	\
+			   && MIDR_PARTNUM(midr) == 0x0a1)
+
+#define IS_THUNDERX2PA(midr) (MIDR_IMPLEMENTOR(midr) == 'B'     \
+			   && MIDR_PARTNUM(midr) == 0x516)
+#define IS_THUNDERX2(midr) (MIDR_IMPLEMENTOR(midr) == 'C'       \
+			   && MIDR_PARTNUM(midr) == 0xaf)
+
+#define IS_NEOVERSE_N1(midr) (MIDR_IMPLEMENTOR(midr) == 'A'		      \
+			      && MIDR_PARTNUM(midr) == 0xd0c)
+#define IS_NEOVERSE_N2(midr) (MIDR_IMPLEMENTOR(midr) == 'A'		      \
+			      && MIDR_PARTNUM(midr) == 0xd49)
+#define IS_NEOVERSE_V1(midr) (MIDR_IMPLEMENTOR(midr) == 'A'		      \
+			      && MIDR_PARTNUM(midr) == 0xd40)
+
+#define IS_EMAG(midr) (MIDR_IMPLEMENTOR(midr) == 'P'			      \
+                       && MIDR_PARTNUM(midr) == 0x000)
+
+#define IS_KUNPENG920(midr) (MIDR_IMPLEMENTOR(midr) == 'H'			   \
+                        && MIDR_PARTNUM(midr) == 0xd01)
+
+#define IS_A64FX(midr) (MIDR_IMPLEMENTOR(midr) == 'F'			      \
+			&& MIDR_PARTNUM(midr) == 0x001)
+
+struct cpu_features
+{
+  uint64_t midr_el1;
+  unsigned zva_size;
+  bool bti;
+  /* Currently, the GLIBC memory tagging tunable only defines 8 bits.  */
+  uint8_t mte_state;
+  bool sve;
+  bool mops;
+};
+
+#endif /* _CPU_FEATURES_AARCH64_H  */
diff --git a/sysdeps/aarch64/libc-start.c b/sysdeps/aarch64/libc-start.c
new file mode 100644
index 0000000000..a29384954d
--- /dev/null
+++ b/sysdeps/aarch64/libc-start.c
@@ -0,0 +1,33 @@
+/* Override csu/libc-start.c on AArch64.
+   Copyright (C) 2017-2024 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#ifndef SHARED
+
+/* Mark symbols hidden in static PIE for early self relocation to work.  */
+# if BUILD_PIE_DEFAULT
+#  pragma GCC visibility push(hidden)
+# endif
+# include <ldsodefs.h>
+# include <cpu-features.c>
+
+extern struct cpu_features _dl_aarch64_cpu_features;
+
+# define ARCH_INIT_CPU_FEATURES() init_cpu_features (&_dl_aarch64_cpu_features)
+
+#endif
+#include <csu/libc-start.c>