diff --git a/sysdeps/mach/hurd/x86/init-first.c b/sysdeps/mach/hurd/x86/init-first.c
index 75ac1ff2..d4e6a4d6 100644
--- a/sysdeps/mach/hurd/x86/init-first.c
+++ b/sysdeps/mach/hurd/x86/init-first.c
@@ -43,8 +43,14 @@ extern char **__libc_argv attribute_hidden;
 extern char **_dl_argv;
 
 #ifndef SHARED
-unsigned short __init1_desc;
 static tcbhead_t __init1_tcbhead;
+# ifndef __x86_64__
+unsigned short __init1_desc;
+# endif
+#endif
+
+#ifdef __x86_64__
+unsigned char __libc_tls_initialized;
 #endif
 
 /* Things that want to be run before _hurd_init or much anything else.
@@ -248,7 +254,13 @@ first_init (void)
   /* In the static case, we need to set up TLS early so that the stack
      protection guard can be read at gs:0x14 by the gcc-generated snippets.  */
   _hurd_tls_init (&__init1_tcbhead);
+
+  /* Make sure __LIBC_NO_TLS () keeps evaluating to 1.  */
+# ifdef __x86_64__
+  __libc_tls_initialized = 0;
+# else
   asm ("movw %%gs,%w0" : "=m" (__init1_desc));
+# endif
 #endif
 
   RUN_RELHOOK (_hurd_preinit_hook, ());
diff --git a/sysdeps/mach/hurd/x86_64/tls.h b/sysdeps/mach/hurd/x86_64/tls.h
new file mode 100644
index 00000000..644dcb1a
--- /dev/null
+++ b/sysdeps/mach/hurd/x86_64/tls.h
@@ -0,0 +1,257 @@
+/* Definitions for thread-local data handling.  Hurd/x86_64 version.
+   Copyright (C) 2003-2023 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 _X86_64_TLS_H
+#define _X86_64_TLS_H
+
+
+/* Some things really need not be machine-dependent.  */
+#include <sysdeps/mach/hurd/tls.h>
+
+
+#ifndef __ASSEMBLER__
+# include <dl-dtv.h>
+# include <mach/machine/thread_status.h>
+# include <errno.h>
+# include <assert.h>
+
+/* Type of the TCB.  */
+typedef struct
+{
+  void *tcb;			/* Points to this structure.  */
+  dtv_t *dtv;			/* Vector of pointers to TLS data.  */
+  thread_t self;		/* This thread's control port.  */
+  int __glibc_padding1;
+  int multiple_threads;
+  int gscope_flag;
+  uintptr_t sysinfo;
+  uintptr_t stack_guard;
+  uintptr_t pointer_guard;
+  long __glibc_padding2[2];
+  int private_futex;
+  int __glibc_padding3;
+  /* Reservation of some values for the TM ABI.  */
+  void *__private_tm[4];
+  /* GCC split stack support.  */
+  void *__private_ss;
+  /* The lowest address of shadow stack.  */
+  unsigned long long int ssp_base;
+
+  /* Keep these fields last, so offsets of fields above can continue being
+     compatible with the x86_64 NPTL version.  */
+  mach_port_t reply_port;      /* This thread's reply port.  */
+  struct hurd_sigstate *_hurd_sigstate;
+
+  /* Used by the exception handling implementation in the dynamic loader.  */
+  struct rtld_catch *rtld_catch;
+} tcbhead_t;
+
+/* GCC generates %fs:0x28 to access the stack guard.  */
+_Static_assert (offsetof (tcbhead_t, stack_guard) == 0x28,
+                "stack guard offset");
+/* libgcc uses %fs:0x70 to access the split stack pointer.  */
+_Static_assert (offsetof (tcbhead_t, __private_ss) == 0x70,
+                "split stack pointer offset");
+
+extern unsigned char __libc_tls_initialized;
+# define __LIBC_NO_TLS() __builtin_expect (!__libc_tls_initialized, 0)
+
+/* The TCB can have any size and the memory following the address the
+   thread pointer points to is unspecified.  Allocate the TCB there.  */
+# define TLS_TCB_AT_TP	1
+# define TLS_DTV_AT_TP	0
+
+# define TCB_ALIGNMENT	64
+
+
+# define TLS_INIT_TP(descr) _hurd_tls_init ((tcbhead_t *) (descr))
+
+# if __GNUC_PREREQ (6, 0)
+
+#  define THREAD_SELF							\
+  (*(tcbhead_t * __seg_fs *) offsetof (tcbhead_t, tcb))
+#  define THREAD_GETMEM(descr, member)					\
+  (*(__typeof (descr->member) __seg_fs *) offsetof (tcbhead_t, member))
+#  define THREAD_SETMEM(descr, member, value)				\
+  (*(__typeof (descr->member) __seg_fs *) offsetof (tcbhead_t, member) = value)
+
+# else
+
+#  define THREAD_SELF							\
+  ({ tcbhead_t *__tcb;							\
+     asm ("movq %%fs:%c1,%0" : "=r" (__tcb)				\
+          : "i" (offsetof (tcbhead_t, tcb)));				\
+     __tcb; })
+
+/* Read member of the thread descriptor directly.  */
+# define THREAD_GETMEM(descr, member) \
+  ({ __typeof (descr->member) __value;					\
+     _Static_assert (sizeof (__value) == 1				\
+                     || sizeof (__value) == 4				\
+                     || sizeof (__value) == 8,				\
+                     "size of per-thread data");			\
+     if (sizeof (__value) == 1)						\
+       asm volatile ("movb %%fs:%P2,%b0"				\
+                     : "=q" (__value)					\
+                     : "0" (0), "i" (offsetof (tcbhead_t, member)));	\
+     else if (sizeof (__value) == 4)					\
+       asm volatile ("movl %%fs:%P1,%0"					\
+                     : "=r" (__value)					\
+                     : "i" (offsetof (tcbhead_t, member)));		\
+     else /* 8 */							\
+       asm volatile ("movq %%fs:%P1,%0"					\
+                     : "=r" (__value)					\
+                     : "i" (offsetof (tcbhead_t, member)));		\
+     __value; })
+
+/* Write member of the thread descriptor directly.  */
+#  define THREAD_SETMEM(descr, member, value) \
+  ({									\
+     _Static_assert (sizeof (descr->member) == 1			\
+                     || sizeof (descr->member) == 4			\
+                     || sizeof (descr->member) == 8,			\
+                     "size of per-thread data");			\
+     if (sizeof (descr->member) == 1)					\
+       asm volatile ("movb %b0,%%fs:%P1" :				\
+                     : "iq" (value),					\
+                       "i" (offsetof (tcbhead_t, member)));		\
+     else if (sizeof (descr->member) == 4)				\
+       asm volatile ("movl %0,%%fs:%P1" :				\
+                     : "ir" (value),					\
+                       "i" (offsetof (tcbhead_t, member)));		\
+     else /* 8 */							\
+       asm volatile ("movq %0,%%fs:%P1" :				\
+                     : "ir" (value),					\
+                       "i" (offsetof (tcbhead_t, member)));		\
+     })
+# endif /* __GNUC_PREREQ (6, 0) */
+
+/* Return the TCB address of a thread given its state.
+   Note: this is expensive.  */
+static inline tcbhead_t * __attribute__ ((unused))
+THREAD_TCB (thread_t thread,
+            const void *all_state __attribute__ ((unused)))
+{
+  error_t err;
+  /* Fetch the target thread's state.  */
+  struct i386_fsgs_base_state state;
+  mach_msg_type_number_t state_count = i386_FSGS_BASE_STATE_COUNT;
+  err = __thread_get_state (thread, i386_FSGS_BASE_STATE,
+                            (thread_state_t) &state,
+                            &state_count);
+  assert_perror (err);
+  assert (state_count == i386_FSGS_BASE_STATE_COUNT);
+  return (tcbhead_t *) state.fs_base;
+}
+
+/* Set the stack guard field in TCB head.  */
+# define THREAD_SET_STACK_GUARD(value)					\
+  THREAD_SETMEM (THREAD_SELF, stack_guard, value)
+# define THREAD_COPY_STACK_GUARD(descr)					\
+  ((descr)->stack_guard							\
+   = THREAD_GETMEM (THREAD_SELF, stack_guard))
+
+/* Set the pointer guard field in the TCB head.  */
+# define THREAD_SET_POINTER_GUARD(value)				\
+  THREAD_SETMEM (THREAD_SELF, pointer_guard, value)
+# define THREAD_COPY_POINTER_GUARD(descr)				\
+  ((descr)->pointer_guard						\
+   = THREAD_GETMEM (THREAD_SELF, pointer_guard))
+
+/* Install new dtv for current thread.  */
+# define INSTALL_NEW_DTV(dtvp) THREAD_SETMEM (THREAD_SELF, dtv, dtvp)
+
+/* Return the address of the dtv for the current thread.  */
+# define THREAD_DTV() THREAD_GETMEM (THREAD_SELF, dtv)
+
+/* Set up TLS in the new thread of a fork child, copying from the original.  */
+static inline kern_return_t __attribute__ ((unused))
+_hurd_tls_fork (thread_t child, thread_t orig,
+                void *machine_state __attribute__ ((unused)))
+{
+  error_t err;
+  struct i386_fsgs_base_state state;
+  mach_msg_type_number_t state_count = i386_FSGS_BASE_STATE_COUNT;
+  err = __thread_get_state (orig, i386_FSGS_BASE_STATE,
+                            (thread_state_t) &state,
+                            &state_count);
+  if (err)
+    return err;
+  assert (state_count == i386_FSGS_BASE_STATE_COUNT);
+
+  return __thread_set_state (child, i386_FSGS_BASE_STATE,
+                             (thread_state_t) &state,
+                             state_count);
+}
+
+static inline kern_return_t __attribute__ ((unused))
+_hurd_tls_new (thread_t child, tcbhead_t *tcb)
+{
+  struct i386_fsgs_base_state state;
+
+  tcb->tcb = tcb;
+  tcb->self = child;
+
+  /* Install the TCB address into FS base.  */
+  state.fs_base = (uintptr_t) tcb;
+  state.gs_base = 0;
+  return __thread_set_state (child, i386_FSGS_BASE_STATE,
+                             (thread_state_t) &state,
+                             i386_FSGS_BASE_STATE_COUNT);
+}
+
+static inline bool __attribute__ ((unused))
+_hurd_tls_init (tcbhead_t *tcb)
+{
+  error_t err;
+  thread_t self = __mach_thread_self ();
+
+  /* We always at least start the sigthread anyway.  */
+  tcb->multiple_threads = 1;
+
+  err = _hurd_tls_new (self, tcb);
+  __mach_port_deallocate (__mach_task_self (), self);
+  __libc_tls_initialized = 1;
+  return err == 0;
+}
+
+
+/* Global scope switch support.  */
+# define THREAD_GSCOPE_FLAG_UNUSED 0
+# define THREAD_GSCOPE_FLAG_USED   1
+# define THREAD_GSCOPE_FLAG_WAIT   2
+
+# define THREAD_GSCOPE_SET_FLAG() \
+  THREAD_SETMEM (THREAD_SELF, gscope_flag, THREAD_GSCOPE_FLAG_USED)
+
+# define THREAD_GSCOPE_RESET_FLAG() \
+  ({									\
+    int __flag;								\
+    asm volatile ("xchgl %0, %%fs:%P1"					\
+                  : "=r" (__flag)					\
+                  : "i" (offsetof (tcbhead_t, gscope_flag)),		\
+                    "0" (THREAD_GSCOPE_FLAG_UNUSED));			\
+    if (__flag == THREAD_GSCOPE_FLAG_WAIT)				\
+      lll_wake (THREAD_SELF->gscope_flag, LLL_PRIVATE);			\
+  })
+
+
+
+#endif	/* __ASSEMBLER__ */
+#endif	/* x86_64/tls.h */
diff --git a/sysdeps/mach/x86_64/thread_state.h b/sysdeps/mach/x86_64/thread_state.h
new file mode 100644
index 00000000..d8c8889f
--- /dev/null
+++ b/sysdeps/mach/x86_64/thread_state.h
@@ -0,0 +1,51 @@
+/* Mach thread state definitions for machine-independent code.  x86_64 version.
+   Copyright (C) 1994-2023 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 _MACH_X86_64_THREAD_STATE_H
+#define _MACH_X86_64_THREAD_STATE_H 1
+
+#include <mach/machine/thread_status.h>
+
+#define MACHINE_NEW_THREAD_STATE_FLAVOR	i386_THREAD_STATE
+#define MACHINE_THREAD_STATE_FLAVOR	i386_THREAD_STATE
+#define MACHINE_THREAD_STATE_COUNT	i386_THREAD_STATE_COUNT
+
+#define machine_thread_state i386_thread_state
+
+#define PC rip
+#define SP ursp
+#define SYSRETURN rax
+
+#define MACHINE_THREAD_STATE_FIX_NEW(ts) do { \
+	asm ("mov %%cs, %w0" : "=q" ((ts)->cs)); \
+	asm ("mov %%ds, %w0" : "=q" ((ts)->ds)); \
+	asm ("mov %%es, %w0" : "=q" ((ts)->es)); \
+	asm ("mov %%fs, %w0" : "=q" ((ts)->fs)); \
+	asm ("mov %%gs, %w0" : "=q" ((ts)->gs)); \
+} while(0)
+
+struct machine_thread_all_state
+  {
+    int set;			/* Mask of bits (1 << FLAVOR).  */
+    struct i386_thread_state basic;
+    struct i386_float_state fpu;
+  };
+
+#include <sysdeps/mach/thread_state.h>
+
+#endif /* mach/x86_64/thread_state.h */
diff --git a/sysdeps/x86_64/htl/bits/pthreadtypes-arch.h b/sysdeps/x86_64/htl/bits/pthreadtypes-arch.h
new file mode 100644
index 00000000..1d402cc6
--- /dev/null
+++ b/sysdeps/x86_64/htl/bits/pthreadtypes-arch.h
@@ -0,0 +1,36 @@
+/* Machine-specific pthread type layouts.  Hurd x86_64 version.
+   Copyright (C) 2002-2023 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 _BITS_PTHREADTYPES_ARCH_H
+#define _BITS_PTHREADTYPES_ARCH_H	1
+
+#define __SIZEOF_PTHREAD_MUTEX_T 32
+#define __SIZEOF_PTHREAD_ATTR_T 48
+#define __SIZEOF_PTHREAD_RWLOCK_T 48
+#define __SIZEOF_PTHREAD_BARRIER_T 40
+#define __SIZEOF_PTHREAD_MUTEXATTR_T 16
+#define __SIZEOF_PTHREAD_COND_T 40
+#define __SIZEOF_PTHREAD_CONDATTR_T 8
+#define __SIZEOF_PTHREAD_RWLOCKATTR_T 4
+#define __SIZEOF_PTHREAD_BARRIERATTR_T 4
+#define __SIZEOF_PTHREAD_ONCE_T 8
+
+#define __LOCK_ALIGNMENT
+#define __ONCE_ALIGNMENT
+
+#endif /* bits/pthreadtypes.h */
diff --git a/sysdeps/x86_64/htl/pt-machdep.h b/sysdeps/x86_64/htl/pt-machdep.h
new file mode 100644
index 00000000..2e2846fa
--- /dev/null
+++ b/sysdeps/x86_64/htl/pt-machdep.h
@@ -0,0 +1,28 @@
+/* Machine dependent pthreads internal defenitions.  x86_64 version.
+   Copyright (C) 2000-2023 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 _PT_MACHDEP_H
+#define _PT_MACHDEP_H	1
+
+struct pthread_mcontext
+{
+  void *pc;
+  void *sp;
+};
+
+#endif /* pt-machdep.h */
