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authorcaiyinyu <caiyinyu@loongson.cn>2023-09-15 17:35:19 +0800
committercaiyinyu <caiyinyu@loongson.cn>2024-04-24 18:22:38 +0800
commit095067efdf68c8061d6f99a21a0300841bede999 (patch)
tree6632c0cb08991fbd2c08809f24320493687c81a6 /sysdeps
parentf4724843ada64a51d66f65d3199fe431f9d4c254 (diff)
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LoongArch: Add glibc.cpu.hwcap support.
The current IFUNC selection is always using the most recent features which are available via AT_HWCAP. But in some scenarios it is useful to adjust this selection. The environment variable: GLIBC_TUNABLES=glibc.cpu.hwcaps=-xxx,yyy,zzz,.... can be used to enable HWCAP feature yyy, disable HWCAP feature xxx, where the feature name is case-sensitive and has to match the ones used in sysdeps/loongarch/cpu-tunables.c. Signed-off-by: caiyinyu <caiyinyu@loongson.cn>
Diffstat (limited to 'sysdeps')
-rw-r--r--sysdeps/loongarch/Makefile12
-rw-r--r--sysdeps/loongarch/cpu-tunables.c87
-rw-r--r--sysdeps/loongarch/dl-get-cpu-features.c25
-rw-r--r--sysdeps/loongarch/dl-machine.h29
-rw-r--r--sysdeps/loongarch/dl-tunables.list25
-rw-r--r--sysdeps/loongarch/lp64/multiarch/dl-symbol-redir-ifunc.h3
-rw-r--r--sysdeps/loongarch/tst-hwcap-tunables.c136
-rw-r--r--sysdeps/unix/sysv/linux/loongarch/cpu-features.c30
-rw-r--r--sysdeps/unix/sysv/linux/loongarch/cpu-features.h17
-rw-r--r--sysdeps/unix/sysv/linux/loongarch/dl-procinfo.c60
-rw-r--r--sysdeps/unix/sysv/linux/loongarch/dl-sysdep.c21
-rw-r--r--sysdeps/unix/sysv/linux/loongarch/libc-start.c34
12 files changed, 471 insertions, 8 deletions
diff --git a/sysdeps/loongarch/Makefile b/sysdeps/loongarch/Makefile
index 43d2f58..446bda6 100644
--- a/sysdeps/loongarch/Makefile
+++ b/sysdeps/loongarch/Makefile
@@ -1,11 +1,23 @@
ifeq ($(subdir),misc)
sysdep_headers += sys/asm.h
+
+tests += \
+ tst-hwcap-tunables \
+ # tests
+
+tst-hwcap-tunables-ARGS = -- $(host-test-program-cmd)
endif
ifeq ($(subdir),elf)
gen-as-const-headers += dl-link.sym
endif
+ifeq ($(subdir),elf)
+sysdep-dl-routines += \
+ dl-get-cpu-features \
+ # sysdep-dl-routines
+endif
+
# LoongArch's assembler also needs to know about PIC as it changes the
# definition of some assembler macros.
ASFLAGS-.os += $(pic-ccflag)
diff --git a/sysdeps/loongarch/cpu-tunables.c b/sysdeps/loongarch/cpu-tunables.c
new file mode 100644
index 0000000..e274e99
--- /dev/null
+++ b/sysdeps/loongarch/cpu-tunables.c
@@ -0,0 +1,87 @@
+/* LoongArch CPU feature tuning.
+ This file is part of the GNU C Library.
+ Copyright (C) 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
+ <http://www.gnu.org/licenses/>. */
+
+#include <stdbool.h>
+#include <stdint.h>
+#include <unistd.h> /* Get STDOUT_FILENO for _dl_printf. */
+#include <elf/dl-tunables.h>
+#include <string.h>
+#include <cpu-features.h>
+#include <ldsodefs.h>
+#include <sys/auxv.h>
+#include <dl-tunables-parse.h>
+#include <dl-symbol-redir-ifunc.h>
+
+#define CHECK_GLIBC_IFUNC_CPU(f, name, len) \
+ _Static_assert (sizeof (#name) - 1 == len, #name " != " #len); \
+ if (tunable_str_comma_strcmp_cte (&f, #name)) \
+ { \
+ if (f.disable) \
+ GLRO(dl_larch_cpu_features).hwcap &= (~HWCAP_LOONGARCH_##name); \
+ else \
+ GLRO(dl_larch_cpu_features).hwcap |= HWCAP_LOONGARCH_##name; \
+ break; \
+ }
+
+attribute_hidden void
+TUNABLE_CALLBACK (set_hwcaps) (tunable_val_t *valp)
+{
+ /* The current IFUNC selection is based on microbenchmarks in glibc.
+ It should give the best performance for most workloads. But other
+ choices may have better performance for a particular workload or on
+ the hardware which wasn't available when the selection was made.
+ The environment variable:
+
+ GLIBC_TUNABLES=glibc.cpu.hwcaps=-xxx,yyy,-zzz,....
+
+ can be used to enable CPU/ARCH feature yyy, disable CPU/ARCH feature
+ yyy and zzz, where the feature name is case-sensitive and has to
+ match the ones in cpu-features.h. It can be used by glibc developers
+ to tune for a new processor or override the IFUNC selection to
+ improve performance for a particular workload.
+
+ NOTE: the IFUNC selection may change over time. Please check all
+ multiarch implementations when experimenting. */
+
+ struct tunable_str_comma_state_t ts;
+ tunable_str_comma_init (&ts, valp);
+
+ struct tunable_str_comma_t n;
+ while (tunable_str_comma_next (&ts, &n))
+ {
+ switch (n.len)
+ {
+ default:
+ break;
+ case 3:
+ {
+ CHECK_GLIBC_IFUNC_CPU (n, LSX, 3);
+ CHECK_GLIBC_IFUNC_CPU (n, UAL, 3);
+ }
+ break;
+ case 4:
+ {
+ CHECK_GLIBC_IFUNC_CPU (n, LASX, 4);
+ }
+ break;
+ }
+ }
+
+ /* Ensure that the user has not enabled any unsupported features. */
+ GLRO(dl_larch_cpu_features).hwcap &= GLRO(dl_hwcap);
+}
diff --git a/sysdeps/loongarch/dl-get-cpu-features.c b/sysdeps/loongarch/dl-get-cpu-features.c
new file mode 100644
index 0000000..3dcecef
--- /dev/null
+++ b/sysdeps/loongarch/dl-get-cpu-features.c
@@ -0,0 +1,25 @@
+/* Define _dl_larch_get_cpu_features.
+ Copyright (C) 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/>. */
+
+
+#include <ldsodefs.h>
+
+const struct cpu_features *
+_dl_larch_get_cpu_features (void)
+{
+ return &GLRO(dl_larch_cpu_features);
+}
diff --git a/sysdeps/loongarch/dl-machine.h b/sysdeps/loongarch/dl-machine.h
index ab81b82..6baf0e6 100644
--- a/sysdeps/loongarch/dl-machine.h
+++ b/sysdeps/loongarch/dl-machine.h
@@ -29,6 +29,8 @@
#include <dl-static-tls.h>
#include <dl-machine-rel.h>
+#include <cpu-features.c>
+
#ifndef _RTLD_PROLOGUE
# define _RTLD_PROLOGUE(entry) \
".globl\t" __STRING (entry) "\n\t" \
@@ -53,6 +55,23 @@
#define ELF_MACHINE_NO_REL 1
#define ELF_MACHINE_NO_RELA 0
+#define DL_PLATFORM_INIT dl_platform_init ()
+
+static inline void __attribute__ ((unused))
+dl_platform_init (void)
+{
+ if (GLRO(dl_platform) != NULL && *GLRO(dl_platform) == '\0')
+ /* Avoid an empty string which would disturb us. */
+ GLRO(dl_platform) = NULL;
+
+#ifdef SHARED
+ /* init_cpu_features has been called early from __libc_start_main in
+ static executable. */
+ init_cpu_features (&GLRO(dl_larch_cpu_features));
+#endif
+}
+
+
/* Return nonzero iff ELF header is compatible with the running host. */
static inline int
elf_machine_matches_host (const ElfW (Ehdr) *ehdr)
@@ -290,10 +309,10 @@ elf_machine_runtime_setup (struct link_map *l, struct r_scope_elem *scope[],
#ifdef SHARED
if (profile != 0)
{
-# if !defined __loongarch_soft_float
- if (SUPPORT_LASX)
+#if !defined __loongarch_soft_float
+ if (RTLD_SUPPORT_LASX)
gotplt[0] = (ElfW(Addr)) &_dl_runtime_profile_lasx;
- else if (SUPPORT_LSX)
+ else if (RTLD_SUPPORT_LSX)
gotplt[0] = (ElfW(Addr)) &_dl_runtime_profile_lsx;
else
# endif
@@ -312,9 +331,9 @@ elf_machine_runtime_setup (struct link_map *l, struct r_scope_elem *scope[],
indicated by the offset on the stack, and then jump to
the resolved address. */
#if !defined __loongarch_soft_float
- if (SUPPORT_LASX)
+ if (RTLD_SUPPORT_LASX)
gotplt[0] = (ElfW(Addr)) &_dl_runtime_resolve_lasx;
- else if (SUPPORT_LSX)
+ else if (RTLD_SUPPORT_LSX)
gotplt[0] = (ElfW(Addr)) &_dl_runtime_resolve_lsx;
else
#endif
diff --git a/sysdeps/loongarch/dl-tunables.list b/sysdeps/loongarch/dl-tunables.list
new file mode 100644
index 0000000..00869a9
--- /dev/null
+++ b/sysdeps/loongarch/dl-tunables.list
@@ -0,0 +1,25 @@
+# LoongArch specific tunables.
+# Copyright (C) 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
+# <http://www.gnu.org/licenses/>.
+
+glibc {
+ cpu {
+ hwcaps {
+ type: STRING
+ }
+ }
+}
diff --git a/sysdeps/loongarch/lp64/multiarch/dl-symbol-redir-ifunc.h b/sysdeps/loongarch/lp64/multiarch/dl-symbol-redir-ifunc.h
index cb640d7..a73390b 100644
--- a/sysdeps/loongarch/lp64/multiarch/dl-symbol-redir-ifunc.h
+++ b/sysdeps/loongarch/lp64/multiarch/dl-symbol-redir-ifunc.h
@@ -19,6 +19,9 @@
#ifndef _DL_IFUNC_GENERIC_H
#define _DL_IFUNC_GENERIC_H
+#ifndef SHARED
asm ("memset = __memset_aligned");
+asm ("memcmp = __memcmp_aligned");
+#endif
#endif
diff --git a/sysdeps/loongarch/tst-hwcap-tunables.c b/sysdeps/loongarch/tst-hwcap-tunables.c
new file mode 100644
index 0000000..fe1b95a
--- /dev/null
+++ b/sysdeps/loongarch/tst-hwcap-tunables.c
@@ -0,0 +1,136 @@
+/* Tests for LoongArch GLIBC_TUNABLES=glibc.cpu.hwcaps filter.
+ Copyright (C) 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
+ <http://www.gnu.org/licenses/>. */
+
+#include <array_length.h>
+#include <getopt.h>
+#include <ifunc-impl-list.h>
+#include <spawn.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <support/check.h>
+#include <support/support.h>
+#include <support/xunistd.h>
+#include <sys/auxv.h>
+#include <sys/wait.h>
+
+/* Nonzero if the program gets called via `exec'. */
+#define CMDLINE_OPTIONS \
+ { "restart", no_argument, &restart, 1 }, \
+ { "enable", no_argument, &enable, 1 },
+static int restart;
+static int enable;
+
+/* Hold the four initial argument used to respawn the process, plus the extra
+ '--direct', '--restart', and the function to check. */
+static char *spargs[9];
+static int fc;
+
+/* Called on process re-execution. */
+_Noreturn static void
+handle_restart (int argc, char *argv[])
+{
+ TEST_VERIFY_EXIT (argc == 1);
+ const char *funcname = argv[0];
+
+ struct libc_ifunc_impl impls[32];
+ int cnt = __libc_ifunc_impl_list ("memcpy", impls, array_length (impls));
+ if (cnt == 0)
+ _exit (EXIT_SUCCESS);
+ TEST_VERIFY_EXIT (cnt >= 1);
+ for (int i = 0; i < cnt; i++)
+ {
+ if (strcmp (impls[i].name, funcname) == 0)
+ {
+ if (enable && impls[i].usable != true)
+ FAIL_EXIT1 ("FAIL: %s ifunc selection is not enabled.\n", funcname);
+ else if (!enable && impls[i].usable != false)
+ FAIL_EXIT1 ("FAIL: %s ifunc selection is not disabled.\n", funcname);
+ break;
+ }
+ }
+
+ _exit (EXIT_SUCCESS);
+}
+
+static void
+run_test (const char *filter, const char *funcname, int disable)
+{
+ if (disable)
+ printf ("info: checking filter %s (expect %s ifunc "
+ "selection to be disabled)\n", filter, funcname);
+ else
+ {
+ printf ("info: checking filter %s (expect %s ifunc "
+ "selection to be enabled)\n", filter, funcname);
+ spargs[fc++] = (char *) "--enable";
+ }
+
+ char *tunable = xasprintf ("GLIBC_TUNABLES=glibc.cpu.hwcaps=%s", filter);
+ char *const newenvs[] = { (char*) tunable, NULL };
+ spargs[fc] = (char *) funcname;
+
+ pid_t pid;
+ TEST_COMPARE (posix_spawn (&pid, spargs[0], NULL, NULL, spargs, newenvs), 0);
+ int status;
+ TEST_COMPARE (xwaitpid (pid, &status, 0), pid);
+ TEST_VERIFY (WIFEXITED (status));
+ TEST_VERIFY (!WIFSIGNALED (status));
+ TEST_COMPARE (WEXITSTATUS (status), 0);
+
+ if (!disable)
+ fc--;
+ free (tunable);
+}
+
+static int
+do_test (int argc, char *argv[])
+{
+ if (restart)
+ handle_restart (argc - 1, &argv[1]);
+
+ TEST_VERIFY_EXIT (argc == 2 || argc == 5);
+
+ int i;
+ for (i = 0; i < argc - 1; i++)
+ spargs[i] = argv[i + 1];
+ spargs[i++] = (char *) "--direct";
+ spargs[i++] = (char *) "--restart";
+ fc = i++;
+ spargs[i] = NULL;
+
+ unsigned long int hwcap = getauxval (AT_HWCAP);
+
+ if (hwcap & HWCAP_LOONGARCH_LASX)
+ run_test ("-LASX", "__memcpy_lasx", 1);
+ if (hwcap & HWCAP_LOONGARCH_LSX)
+ run_test ("-LSX", "__memcpy_lsx", 1);
+ if (hwcap & HWCAP_LOONGARCH_UAL)
+ run_test ("-UAL", "__memcpy_unaligned", 1);
+
+ /* __memcpy_aligned is the default ifunc selection and will be
+ * always enabled. */
+ run_test ("-LASX,-LSX,-UAL", "__memcpy_aligned", 0);
+ run_test ("-LASX,-LSX", "__memcpy_aligned", 0);
+ run_test ("-LASX", "__memcpy_aligned", 0);
+
+ return 0;
+}
+
+#define TEST_FUNCTION_ARGV do_test
+#include <support/test-driver.c>
diff --git a/sysdeps/unix/sysv/linux/loongarch/cpu-features.c b/sysdeps/unix/sysv/linux/loongarch/cpu-features.c
new file mode 100644
index 0000000..ba6201a
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/loongarch/cpu-features.c
@@ -0,0 +1,30 @@
+/* Initialize CPU feature data. LoongArch64 version.
+ This file is part of the GNU C Library.
+ Copyright (C) 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
+ <http://www.gnu.org/licenses/>. */
+
+#include <cpu-features.h>
+#include <elf/dl-hwcaps.h>
+#include <elf/dl-tunables.h>
+extern void TUNABLE_CALLBACK (set_hwcaps) (tunable_val_t *) attribute_hidden;
+
+static inline void
+init_cpu_features (struct cpu_features *cpu_features)
+{
+ GLRO(dl_larch_cpu_features).hwcap = GLRO(dl_hwcap);
+ TUNABLE_GET (glibc, cpu, hwcaps, tunable_val_t *,
+ TUNABLE_CALLBACK (set_hwcaps));
+}
diff --git a/sysdeps/unix/sysv/linux/loongarch/cpu-features.h b/sysdeps/unix/sysv/linux/loongarch/cpu-features.h
index 4e863c7..eec5195 100644
--- a/sysdeps/unix/sysv/linux/loongarch/cpu-features.h
+++ b/sysdeps/unix/sysv/linux/loongarch/cpu-features.h
@@ -19,12 +19,23 @@
#ifndef _CPU_FEATURES_LOONGARCH64_H
#define _CPU_FEATURES_LOONGARCH64_H
+#include <stdint.h>
#include <sys/auxv.h>
-#define SUPPORT_UAL (GLRO (dl_hwcap) & HWCAP_LOONGARCH_UAL)
-#define SUPPORT_LSX (GLRO (dl_hwcap) & HWCAP_LOONGARCH_LSX)
-#define SUPPORT_LASX (GLRO (dl_hwcap) & HWCAP_LOONGARCH_LASX)
+struct cpu_features
+{
+ uint64_t hwcap;
+};
+/* Get a pointer to the CPU features structure. */
+extern const struct cpu_features *
+_dl_larch_get_cpu_features (void) __attribute__ ((pure));
+
+#define SUPPORT_UAL (GLRO (dl_larch_cpu_features).hwcap & HWCAP_LOONGARCH_UAL)
+#define SUPPORT_LSX (GLRO (dl_larch_cpu_features).hwcap & HWCAP_LOONGARCH_LSX)
+#define SUPPORT_LASX (GLRO (dl_larch_cpu_features).hwcap & HWCAP_LOONGARCH_LASX)
+#define RTLD_SUPPORT_LSX (GLRO (dl_hwcap) & HWCAP_LOONGARCH_LSX)
+#define RTLD_SUPPORT_LASX (GLRO (dl_hwcap) & HWCAP_LOONGARCH_LASX)
#define INIT_ARCH()
#endif /* _CPU_FEATURES_LOONGARCH64_H */
diff --git a/sysdeps/unix/sysv/linux/loongarch/dl-procinfo.c b/sysdeps/unix/sysv/linux/loongarch/dl-procinfo.c
new file mode 100644
index 0000000..5e056a1
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/loongarch/dl-procinfo.c
@@ -0,0 +1,60 @@
+/* Data for LoongArch64 version of processor capability information.
+ Linux version.
+ Copyright (C) 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
+ <http://www.gnu.org/licenses/>. */
+
+/* If anything should be added here check whether the size of each string
+ is still ok with the given array size.
+
+ All the #ifdefs in the definitions are quite irritating but
+ necessary if we want to avoid duplicating the information. There
+ are three different modes:
+
+ - PROCINFO_DECL is defined. This means we are only interested in
+ declarations.
+
+ - PROCINFO_DECL is not defined:
+
+ + if SHARED is defined the file is included in an array
+ initializer. The .element = { ... } syntax is needed.
+
+ + if SHARED is not defined a normal array initialization is
+ needed.
+ */
+
+#ifndef PROCINFO_CLASS
+# define PROCINFO_CLASS
+#endif
+
+#if !IS_IN (ldconfig)
+# if !defined PROCINFO_DECL && defined SHARED
+ ._dl_larch_cpu_features
+# else
+PROCINFO_CLASS struct cpu_features _dl_larch_cpu_features
+# endif
+# ifndef PROCINFO_DECL
+= { }
+# endif
+# if !defined SHARED || defined PROCINFO_DECL
+;
+# else
+,
+# endif
+#endif
+
+#undef PROCINFO_DECL
+#undef PROCINFO_CLASS
diff --git a/sysdeps/unix/sysv/linux/loongarch/dl-sysdep.c b/sysdeps/unix/sysv/linux/loongarch/dl-sysdep.c
new file mode 100644
index 0000000..30b84f1
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/loongarch/dl-sysdep.c
@@ -0,0 +1,21 @@
+/* Operating system support for run-time dynamic linker. LoongArch version.
+ Copyright (C) 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
+ <http://www.gnu.org/licenses/>. */
+
+#include <config.h>
+#include <sysdeps/loongarch/cpu-tunables.c>
+#include <sysdeps/unix/sysv/linux/dl-sysdep.c>
diff --git a/sysdeps/unix/sysv/linux/loongarch/libc-start.c b/sysdeps/unix/sysv/linux/loongarch/libc-start.c
new file mode 100644
index 0000000..e545f7f
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/loongarch/libc-start.c
@@ -0,0 +1,34 @@
+/* Override csu/libc-start.c on LoongArch64.
+ Copyright (C) 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
+ <http://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_larch_cpu_features;
+
+#define ARCH_INIT_CPU_FEATURES() init_cpu_features (&_dl_larch_cpu_features)
+
+#endif
+#include <csu/libc-start.c>