[OpenRISC] [PATCH v4 05/13] or1k: Thread Local Storage support

Stafford Horne
2021-12-29T04:42:43Z

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.
---
sysdeps/or1k/dl-tls.h | 27 ++++++
sysdeps/or1k/libc-tls.c | 34 ++++++++
sysdeps/or1k/nptl/tls.h | 184 +++++++++++++++++++++++++++++++++++++++
sysdeps/or1k/stackinfo.h | 34 ++++++++
4 files changed, 279 insertions(+)
create mode 100644 sysdeps/or1k/dl-tls.h
create mode 100644 sysdeps/or1k/libc-tls.c
create mode 100644 sysdeps/or1k/nptl/tls.h
create mode 100644 sysdeps/or1k/stackinfo.h

diff --git a/sysdeps/or1k/dl-tls.h b/sysdeps/or1k/dl-tls.h
new file mode 100644
index 0000000000..382588d504
--- /dev/null
+++ b/sysdeps/or1k/dl-tls.h
@@ -0,0 +1,27 @@
+/* TLS definitions for the ELF dynamic linker. OpenRISC version.
+ Copyright (C) 2021 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/>. */
+
+/* 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;
+
+extern void *__tls_get_addr (tls_index *ti);
diff --git a/sysdeps/or1k/libc-tls.c b/sysdeps/or1k/libc-tls.c
new file mode 100644
index 0000000000..1524855e88
--- /dev/null
+++ b/sysdeps/or1k/libc-tls.c
@@ -0,0 +1,34 @@
+/* Thread-local storage handling in the ELF dynamic linker.
+ OpenRISC version.
+ Copyright (C) 2021 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/>. */
+
+#include <csu/libc-tls.c>
+#include <dl-tls.h>
+
+/* On OpenRISC, 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 + ti->ti_offset;
+}
diff --git a/sysdeps/or1k/nptl/tls.h b/sysdeps/or1k/nptl/tls.h
new file mode 100644
index 0000000000..c9e86add6d
--- /dev/null
+++ b/sysdeps/or1k/nptl/tls.h
@@ -0,0 +1,184 @@
+/* Definition for thread-local data handling. NPTL/OpenRISC version.
+ Copyright (C) 2021 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 */
diff --git a/sysdeps/or1k/stackinfo.h b/sysdeps/or1k/stackinfo.h
new file mode 100644
index 0000000000..9273e709bd
--- /dev/null
+++ b/sysdeps/or1k/stackinfo.h
@@ -0,0 +1,34 @@
+/* Stack definitions for OpenRISC.
+ Copyright (C) 2021 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/>. */
+
+/* This file contains a bit of information about the stack allocation
+ of the processor. */
+
+#ifndef _STACKINFO_H
+#define _STACKINFO_H 1
+
+#include <elf.h>
+
+/* On or1k the stack grows down. */
+#define _STACK_GROWS_DOWN 1
+
+/* Default to an executable stack. PF_X can be overridden if PT_GNU_STACK is
+ present, but it is presumed absent. */
+#define DEFAULT_STACK_PERMS (PF_R | PF_W | PF_X)
+
+#endif /* stackinfo.h */
--
2.31.1