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.

1 files changed, 178 insertions, 0 deletions

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 */