m68k: add NPTL/TLS support

Port over NPTL/TLS support from GNU C Library.
In the first step only the slower syscall is used for TLS
access. The uClibc-ng testsuite shows 79 errors, so their
is room for bugfixes and improvements.

9 files changed, 400 insertions, 0 deletions

diff --git a/libpthread/nptl/sysdeps/m68k/Makefile b/libpthread/nptl/sysdeps/m68k/Makefile
new file mode 100644
index 000000000..43dc60a42
--- /dev/null
+++ b/libpthread/nptl/sysdeps/m68k/Makefile
@@ -0,0 +1,6 @@
+top_srcdir=../../../../
+top_builddir=../../../../
+all: objs
+include $(top_builddir)Rules.mak
+include Makefile.arch
+include $(top_srcdir)Makerules
diff --git a/libpthread/nptl/sysdeps/m68k/Makefile.arch b/libpthread/nptl/sysdeps/m68k/Makefile.arch
new file mode 100644
index 000000000..7f6e1cd5b
--- /dev/null
+++ b/libpthread/nptl/sysdeps/m68k/Makefile.arch
@@ -0,0 +1 @@
+libc_arch_a_CSRC = libc-tls.c
diff --git a/libpthread/nptl/sysdeps/m68k/dl-tls.h b/libpthread/nptl/sysdeps/m68k/dl-tls.h
new file mode 100644
index 000000000..c0af06e1e
--- /dev/null
+++ b/libpthread/nptl/sysdeps/m68k/dl-tls.h
@@ -0,0 +1,46 @@
+/* Thread-local storage handling in the ELF dynamic linker.  M68K version.
+   Copyright (C) 2010-2017 Free Software Foundation, Inc.
+   Contributed by Maxim Kuvyrkov <maxim@codesourcery.com>, 2010.
+
+   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/>.  */
+
+
+/* Type used for the representation of TLS information in the GOT.  */
+typedef struct
+{
+  unsigned long int ti_module;
+  unsigned long int ti_offset;
+} tls_index;
+
+/* The thread pointer points 0x7000 past the first static TLS block.  */
+#define TLS_TP_OFFSET		0x7000
+
+/* Dynamic thread vector pointers point 0x8000 past the start of each
+   TLS block.  */
+#define TLS_DTV_OFFSET		0x8000
+
+/* Compute the value for a TPREL reloc.  */
+#define TLS_TPREL_VALUE(sym_map, sym, reloc)				\
+  ((sym_map)->l_tls_offset + (sym)->st_value + (reloc)->r_addend	\
+   - TLS_TP_OFFSET)
+
+/* Compute the value for a DTPREL reloc.  */
+#define TLS_DTPREL_VALUE(sym, reloc)				\
+  ((sym)->st_value + (reloc)->r_addend - TLS_DTV_OFFSET)
+
+extern void *__tls_get_addr (tls_index *ti);
+
+#define GET_ADDR_OFFSET		(ti->ti_offset + TLS_DTV_OFFSET)
+#define __TLS_GET_ADDR(__ti)	(__tls_get_addr (__ti) - TLS_DTV_OFFSET)
diff --git a/libpthread/nptl/sysdeps/m68k/libc-tls.c b/libpthread/nptl/sysdeps/m68k/libc-tls.c
new file mode 100644
index 000000000..50fc030af
--- /dev/null
+++ b/libpthread/nptl/sysdeps/m68k/libc-tls.c
@@ -0,0 +1,32 @@
+/* Thread-local storage handling in the ELF dynamic linker.  m68k version.
+   Copyright (C) 2010-2017 Free Software Foundation, Inc.
+   Contributed by Maxim Kuvyrkov <maxim@codesourcery.com>, 2010.
+
+   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 <sysdeps/generic/libc-tls.c>
+#include <dl-tls.h>
+
+/* On M68K, linker optimizations are not required, so __tls_get_addr
+   can be called even in statically linked binaries.  In this case module
+   must be always 1 and PT_TLS segment exist in the binary, otherwise it
+   would not link.  */
+
+void *
+__tls_get_addr (tls_index *ti)
+{
+  dtv_t *dtv = THREAD_DTV ();
+  return (char *) dtv[1].pointer.val + GET_ADDR_OFFSET;
+}
diff --git a/libpthread/nptl/sysdeps/m68k/pthread_spin_lock.c b/libpthread/nptl/sysdeps/m68k/pthread_spin_lock.c
new file mode 100644
index 000000000..cec3acbc6
--- /dev/null
+++ b/libpthread/nptl/sysdeps/m68k/pthread_spin_lock.c
@@ -0,0 +1,65 @@
+/* pthread_spin_lock -- lock a spin lock.  Generic version.
+   Copyright (C) 2012-2016 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 <atomic.h>
+#include "pthreadP.h"
+
+/* A machine-specific version can define SPIN_LOCK_READS_BETWEEN_CMPXCHG
+  to the number of plain reads that it's optimal to spin on between uses
+  of atomic_compare_and_exchange_val_acq.  If spinning forever is optimal
+  then use -1.  If no plain reads here would ever be optimal, use 0.  */
+#define SPIN_LOCK_READS_BETWEEN_CMPXCHG 1000
+
+int
+pthread_spin_lock (pthread_spinlock_t *lock)
+{
+  /* atomic_exchange usually takes less instructions than
+     atomic_compare_and_exchange.  On the other hand,
+     atomic_compare_and_exchange potentially generates less bus traffic
+     when the lock is locked.
+     We assume that the first try mostly will be successful, and we use
+     atomic_exchange.  For the subsequent tries we use
+     atomic_compare_and_exchange.  */
+  if (atomic_exchange_acq (lock, 1) == 0)
+    return 0;
+
+  do
+    {
+      /* The lock is contended and we need to wait.  Going straight back
+	 to cmpxchg is not a good idea on many targets as that will force
+	 expensive memory synchronizations among processors and penalize other
+	 running threads.
+	 On the other hand, we do want to update memory state on the local core
+	 once in a while to avoid spinning indefinitely until some event that
+	 will happen to update local memory as a side-effect.  */
+      if (SPIN_LOCK_READS_BETWEEN_CMPXCHG >= 0)
+	{
+	  int wait = SPIN_LOCK_READS_BETWEEN_CMPXCHG;
+
+	  while (*lock != 0 && wait > 0)
+	    --wait;
+	}
+      else
+	{
+	  while (*lock != 0)
+	    ;
+	}
+    }
+  while (atomic_compare_and_exchange_val_acq (lock, 1, 0) != 0);
+
+  return 0;
+}
diff --git a/libpthread/nptl/sysdeps/m68k/pthread_spin_trylock.c b/libpthread/nptl/sysdeps/m68k/pthread_spin_trylock.c
new file mode 100644
index 000000000..4e9aa64d3
--- /dev/null
+++ b/libpthread/nptl/sysdeps/m68k/pthread_spin_trylock.c
@@ -0,0 +1,26 @@
+/* pthread_spin_trylock -- trylock a spin lock.  Generic version.
+   Copyright (C) 2012-2016 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 <errno.h>
+#include <atomic.h>
+#include "pthreadP.h"
+
+int
+pthread_spin_trylock (pthread_spinlock_t *lock)
+{
+  return atomic_exchange_acq (lock, 1) ? EBUSY : 0;
+}
diff --git a/libpthread/nptl/sysdeps/m68k/pthreaddef.h b/libpthread/nptl/sysdeps/m68k/pthreaddef.h
new file mode 100644
index 000000000..1651b3d5f
--- /dev/null
+++ b/libpthread/nptl/sysdeps/m68k/pthreaddef.h
@@ -0,0 +1,36 @@
+/* Copyright (C) 2010-2017 Free Software Foundation, Inc.
+   Contributed by Maxim Kuvyrkov <maxim@codesourcery.com>, 2010.
+
+   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/>.  */
+
+/* Default stack size.  */
+#define ARCH_STACK_DEFAULT_SIZE	(2 * 1024 * 1024)
+
+/* Required stack pointer alignment at beginning.  */
+#define STACK_ALIGN		16
+
+/* Minimal stack size after allocating thread descriptor and guard size.  */
+#define MINIMAL_REST_STACK	2048
+
+/* Alignment requirement for TCB.  */
+#define TCB_ALIGNMENT		16
+
+/* Location of current stack frame.  */
+#define CURRENT_STACK_FRAME	__builtin_frame_address (0)
+
+/* XXX Until we have a better place keep the definitions here.  */
+#define __exit_thread_inline(val) \
+  INLINE_SYSCALL (exit, 1, (val))
+
diff --git a/libpthread/nptl/sysdeps/m68k/tcb-offsets.sym b/libpthread/nptl/sysdeps/m68k/tcb-offsets.sym
new file mode 100644
index 000000000..241fb8b47
--- /dev/null
+++ b/libpthread/nptl/sysdeps/m68k/tcb-offsets.sym
@@ -0,0 +1,10 @@
+#include <sysdep.h>
+#include <tls.h>
+
+--
+
+-- Derive offsets relative to the thread register.
+#define thread_offsetof(mem)	(long)(offsetof(struct pthread, mem) - TLS_TCB_OFFSET - TLS_PRE_TCB_SIZE)
+
+MULTIPLE_THREADS_OFFSET		thread_offsetof (header.multiple_threads)
+TID_OFFSET			thread_offsetof (tid)
diff --git a/libpthread/nptl/sysdeps/m68k/tls.h b/libpthread/nptl/sysdeps/m68k/tls.h
new file mode 100644
index 000000000..213442da4
--- /dev/null
+++ b/libpthread/nptl/sysdeps/m68k/tls.h
@@ -0,0 +1,178 @@
+/* Definition for thread-local data handling.  NPTL/m68k version.
+   Copyright (C) 2010-2017 Free Software Foundation, Inc.
+   Contributed by Maxim Kuvyrkov <maxim@codesourcery.com>, 2010.
+
+   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 _TLS_H
+#define _TLS_H	1
+
+#ifndef __ASSEMBLER__
+# include <stdbool.h>
+# include <stddef.h>
+# include <stdint.h>
+
+/* Type for the dtv.  */
+typedef union dtv
+{
+  size_t counter;
+  struct
+  {
+    void *val;
+    bool is_static;
+  } pointer;
+} dtv_t;
+
+/* Value used for dtv entries for which the allocation is delayed.  */
+#define TLS_DTV_UNALLOCATED ((void *) -1l)
+
+#else /* __ASSEMBLER__ */
+# include <tcb-offsets.h>
+#endif /* __ASSEMBLER__ */
+
+/* We require TLS support in the tools.  */
+#define HAVE_TLS_SUPPORT                1
+#define HAVE_TLS_MODEL_ATTRIBUTE        1
+#define HAVE___THREAD                   1
+
+/* Signal that TLS support is available.  */
+#define USE_TLS	1
+
+#ifndef __ASSEMBLER__
+
+/* Get system call information.  */
+# include <sysdep.h>
+
+/* The TP points to the start of the thread blocks.  */
+# define TLS_DTV_AT_TP	1
+
+/* Get the thread descriptor definition.  */
+# include <../../descr.h>
+
+typedef struct
+{
+  dtv_t *dtv;
+  void *private;
+} tcbhead_t;
+
+/* This is the size of the initial TCB.  Because our TCB is before the thread
+   pointer, we don't need this.  */
+# define TLS_INIT_TCB_SIZE	0
+
+/* Alignment requirements for the initial TCB.  */
+# define TLS_INIT_TCB_ALIGN	__alignof__ (struct pthread)
+
+/* This is the size of the TCB.  Because our TCB is before the thread
+   pointer, we don't need this.  */
+# define TLS_TCB_SIZE		0
+
+/* Alignment requirements for the TCB.  */
+# define TLS_TCB_ALIGN		__alignof__ (struct pthread)
+
+/* This is the size we need before TCB - actually, it includes the TCB.  */
+# define TLS_PRE_TCB_SIZE						\
+  (sizeof (struct pthread)						\
+   + ((sizeof (tcbhead_t) + TLS_TCB_ALIGN - 1) & ~(TLS_TCB_ALIGN - 1)))
+
+/* The thread pointer (TP) points to the end of the
+   TCB + 0x7000, as for PowerPC and MIPS.  This implies that TCB address is
+   TP - 0x7000.  As we define TLS_DTV_AT_TP we can
+   assume that the pthread struct is allocated immediately ahead of the
+   TCB.  This implies that the pthread_descr address is
+   TP - (TLS_PRE_TCB_SIZE + 0x7000).  */
+# define TLS_TCB_OFFSET	0x7000
+
+/* Install the dtv pointer.  The pointer passed is to the element with
+   index -1 which contain the length.  */
+# define INSTALL_DTV(tcbp, dtvp) \
+  ((tcbhead_t *) (tcbp))[-1].dtv = dtvp + 1
+
+/* Install new dtv for current thread.  */
+# define INSTALL_NEW_DTV(dtv) \
+  (THREAD_DTV () = (dtv))
+
+/* Return dtv of given thread descriptor.  */
+# define GET_DTV(tcbp) \
+  (((tcbhead_t *) (tcbp))[-1].dtv)
+
+/* Code to initially initialize the thread pointer.  This might need
+   special attention since 'errno' is not yet available and if the
+   operation can cause a failure 'errno' must not be touched.  */
+# define TLS_INIT_TP(tcbp, secondcall)					\
+  ({									\
+    INTERNAL_SYSCALL_DECL (err);					\
+    int result_var;							\
+    result_var = INTERNAL_SYSCALL (set_thread_area, err, 1,		\
+			    ((void *) (tcbp)) + TLS_TCB_OFFSET); 	\
+    INTERNAL_SYSCALL_ERROR_P (result_var, err) 				\
+      ? "unknown error" : NULL; })
+
+# define TLS_DEFINE_INIT_TP(tp, pd) \
+  void *tp = (void *) (pd) + TLS_TCB_OFFSET + TLS_PRE_TCB_SIZE
+
+extern void * __m68k_read_tp (void);
+
+/* Return the address of the dtv for the current thread.  */
+# define THREAD_DTV() \
+  (((tcbhead_t *) (__m68k_read_tp () - TLS_TCB_OFFSET))[-1].dtv)
+
+/* Return the thread descriptor for the current thread.  */
+# define THREAD_SELF \
+  ((struct pthread *) (__m68k_read_tp () - TLS_TCB_OFFSET - TLS_PRE_TCB_SIZE))
+
+/* Magic for libthread_db to know how to do THREAD_SELF.  */
+# define DB_THREAD_SELF \
+  CONST_THREAD_AREA (32, TLS_TCB_OFFSET + TLS_PRE_TCB_SIZE)
+
+/* Access to data in the thread descriptor is easy.  */
+# define THREAD_GETMEM(descr, member) \
+  descr->member
+# define THREAD_GETMEM_NC(descr, member, idx) \
+  descr->member[idx]
+# define THREAD_SETMEM(descr, member, value) \
+  descr->member = (value)
+# define THREAD_SETMEM_NC(descr, member, idx, value) \
+  descr->member[idx] = (value)
+
+/* l_tls_offset == 0 is perfectly valid on M68K, so we have to use some
+   different value to mean unset l_tls_offset.  */
+# define NO_TLS_OFFSET		-1
+
+/* Get and set the global scope generation counter in struct pthread.  */
+#define THREAD_GSCOPE_FLAG_UNUSED 0
+#define THREAD_GSCOPE_FLAG_USED   1
+#define THREAD_GSCOPE_FLAG_WAIT   2
+#define THREAD_GSCOPE_RESET_FLAG()					\
+  do									\
+    { int __res								\
+	= atomic_exchange_rel (&THREAD_SELF->header.gscope_flag,	\
+			       THREAD_GSCOPE_FLAG_UNUSED);		\
+      if (__res == THREAD_GSCOPE_FLAG_WAIT)				\
+	lll_futex_wake (&THREAD_SELF->header.gscope_flag, 1, LLL_PRIVATE); \
+    }									\
+  while (0)
+#define THREAD_GSCOPE_SET_FLAG()					\
+  do									\
+    {									\
+      THREAD_SELF->header.gscope_flag = THREAD_GSCOPE_FLAG_USED;	\
+      atomic_write_barrier ();						\
+    }									\
+  while (0)
+#define THREAD_GSCOPE_WAIT() \
+  GL(dl_wait_lookup_done) ()
+
+#endif /* __ASSEMBLER__ */
+
+#endif	/* tls.h */