or1k: Thread Local Storage support

OpenRISC includes 3 TLS addressing models.  Local Dynamic optimizations
are not done in the linker and therefore use the same code sequences as
Global Dynamic.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>

1 files changed, 184 insertions, 0 deletions

diff --git a/sysdeps/or1k/nptl/tls.h b/sysdeps/or1k/nptl/tls.h
new file mode 100644
index 0000000000..c6ffe62c3f
--- /dev/null
+++ b/sysdeps/or1k/nptl/tls.h
@@ -0,0 +1,184 @@
+/* Definition for thread-local data handling.  NPTL/OpenRISC version.
+   Copyright (C) 2022 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 _TLS_H
+#define _TLS_H  1
+
+#include <dl-sysdep.h>
+
+#ifndef __ASSEMBLER__
+# include <stdbool.h>
+# include <stddef.h>
+# include <stdint.h>
+# include <dl-dtv.h>
+
+typedef struct
+{
+  dtv_t *dtv;
+  void *__padding[3];
+} tcbhead_t;
+
+register tcbhead_t *__thread_self __asm__("r10");
+
+# define TLS_MULTIPLE_THREADS_IN_TCB 1
+
+/* Get system call information.  */
+# include <sysdep.h>
+
+/* The TP points to the start of the TLS block.
+   As I understand it, this isn't strictly that "TP points to DTV" - it's
+   more where to place the TCB in the TLS block.  This will place it in
+   the beginning.
+
+   Layout:
+    +-----+-----+----------------------+
+    | PRE | TCB | TLS MEMORY ..        |
+    +-----+-----+----------------------+
+		 ^ r10 / TP
+
+   PRE is the struct pthread described below
+   TCB is tcbhead_t
+   TLS memory is where the TLS program sections are loaded
+
+   See _dl_allocate_tls_storage and __libc_setup_tls for more information.  */
+
+# define TLS_DTV_AT_TP  1
+# define TLS_TCB_AT_TP  0
+
+/* Get the thread descriptor definition.  */
+# include <nptl/descr.h>
+
+/* Requirements for the TCB.  */
+# define TLS_INIT_TCB_SIZE    sizeof (tcbhead_t)
+# define TLS_INIT_TCB_ALIGN   __alignof__ (struct pthread)
+
+# define TLS_TCB_SIZE         sizeof (tcbhead_t)
+# define TLS_TCB_ALIGN        __alignof__ (struct pthread)
+
+/* This is the size of the TCB.  */
+
+/* This is the size we need before TCB.
+   To support THREAD_GETMEM with friends we want to have a
+   struct pthread available.
+   Yank it in infront of everything, I'm sure nobody will mind.
+
+   This memory is really allocated PRE the TLS block, so it's possible
+   to do ((char*)tlsblock) - TLS_PRE_TCB_SIZE to access it.
+   This is done for THREAD_SELF.  */
+
+# define TLS_PRE_TCB_SIZE sizeof (struct pthread)
+
+/* Install the dtv pointer.
+   When called, dtvp is a pointer not the DTV per say (which should start
+   with the generation counter) but to the length of the DTV.
+   We can always index with -1, so we store dtvp[1].  */
+
+# define INSTALL_DTV(tcbp, dtvp) \
+  (((tcbhead_t *) (tcbp))->dtv = (dtvp) + 1)
+
+/* Install new dtv for current thread
+   In a logicial world dtv here would also point to the length of the DTV.
+   However it does not, this time it points to the generation counter,
+   so just store it.
+
+   Note: -1 is still valid and contains the length.  */
+
+# define INSTALL_NEW_DTV(dtv) (THREAD_DTV() = (dtv))
+
+/* Return dtv of given thread descriptor.  */
+# define GET_DTV(tcbp) (((tcbhead_t *) (tcbp))->dtv)
+
+/* Code to initially initialize the thread pointer.
+
+   Set TP to the address _after_ tcbhead_t.  This will allow us
+   to change the size of tcbhead_t without having to re-link everything.
+
+   This has to return NULL on success (or a string with the failure text).
+   It's hard to fail this, so return NULL always.  */
+
+# define TLS_INIT_TP(tcbp) \
+  ({__thread_self = ((tcbhead_t *)tcbp + 1); NULL;})
+
+/* Value passed to 'clone' for initialization of the thread register.  */
+# define TLS_DEFINE_INIT_TP(tp, pd) \
+  void *tp = ((char *) pd + TLS_PRE_TCB_SIZE + TLS_INIT_TCB_SIZE)
+
+/* Return the address of the dtv for the current thread.
+
+   Dereference TP, offset to dtv - really straightforward.
+   Remember that we made TP point to after tcb, so we need to reverse that.  */
+
+#  define THREAD_DTV() \
+  ((((tcbhead_t *)__thread_self)-1)->dtv)
+
+/* Return the thread descriptor for the current thread.
+
+   Return a pointer to the TLS_PRE area where we allocated space for
+   a struct pthread.  Again, TP points to after tcbhead_t, compensate with
+   TLS_INIT_TCB_SIZE.
+
+   I regard this is a seperate system from the "normal" TLS.  */
+
+# define THREAD_SELF \
+  ((struct pthread *) ((char *) __thread_self - TLS_INIT_TCB_SIZE \
+    - TLS_PRE_TCB_SIZE))
+
+/* Magic for libthread_db to know how to do THREAD_SELF.  */
+
+# define DB_THREAD_SELF \
+  REGISTER (32, 32, 10 * 4, - TLS_INIT_TCB_SIZE - TLS_PRE_TCB_SIZE)
+
+# include <tcb-access.h>
+
+/* 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)
+
+/* 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)
+
+#endif /* __ASSEMBLER__ */
+
+#endif  /* tls.h */