[RFC] [PATCH] PPC32 R2 thread register support

Franz Sirl Franz.Sirl-kernel@lauterbach.com
Mon Feb 17 19:45:00 GMT 2003


Hi,

this patch adds simple (no __thread, no TLS) thread register support to glibc. 
It's been running for over a month now here without a single problem.

I've flagged it RFC, cause I want to make sure this doesn't ABI conflict with 
any __thread or TLS work-in-progress.

Franz.


2003-02-17  Kevin B. Hendricks  <kevin.hendricks@sympatico.ca>
                  Franz Sirl  <Franz.Sirl-kernel@lauterbach.com>

	* sysdeps/powerpc/elf/libc-start.c: Handle NONTLS_INIT_TP.
	* sysdeps/powerpc/powerpc32/__longjmp.S: Remove R2 handling.
	* sysdeps/powerpc/powerpc32/setjmp.S: Likewise.
	* sysdeps/powerpc/powerpc32/fpu/__longjmp.S: Likewise.
	* sysdeps/powerpc/powerpc32/fpu/setjmp.S: Likewise.

linuxthreads/
	* sysdeps/powerpc/Makefile: Handle tcb-offsets.sym.
	* sysdeps/powerpc/tcb-offsets.sym: New file.
	* sysdeps/powerpc/tls.h: New file.
	* sysdeps/powerpc/powerpc32/pt-machine.h (FLOATING_STACKS): Define.
	(ARCH_STACK_MAX_SIZE): Define.
	(THREAD_SELF): Define.
	(INIT_THREAD_SELF): Define.
	(THREAD_GETMEM): Define.
	(THREAD_GETMEM_NC): Define.
	(THREAD_SETMEM): Define.
	(THREAD_SETMEM_NC): Define.
	(__thread_self): Declare.
	* sysdeps/unix/sysv/linux/powerpc/powerpc32/sysdep-cancel.h: Adjust
	for thread register.
-------------- next part --------------
Index: linuxthreads/sysdeps/powerpc/Makefile
===================================================================
RCS file: /cvs/glibc/libc/linuxthreads/sysdeps/powerpc/Makefile,v
retrieving revision 1.1
diff -u -p -r1.1 Makefile
--- linuxthreads/sysdeps/powerpc/Makefile	3 Sep 2002 03:11:22 -0000	1.1
+++ linuxthreads/sysdeps/powerpc/Makefile	17 Feb 2003 19:20:40 -0000
@@ -2,3 +2,6 @@ ifeq ($(subdir):$(elf),linuxthreads:yes)
 # See CFLAGS-initfini.s above; this is the same code.
 CFLAGS-pt-initfini.s = -g0 -fpic -O1
 endif
+ifeq ($(subdir),csu)
+gen-as-const-headers += tcb-offsets.sym
+endif
Index: linuxthreads/sysdeps/powerpc/powerpc32/pt-machine.h
===================================================================
RCS file: /cvs/glibc/libc/linuxthreads/sysdeps/powerpc/powerpc32/pt-machine.h,v
retrieving revision 1.1
diff -u -p -r1.1 pt-machine.h
--- linuxthreads/sysdeps/powerpc/powerpc32/pt-machine.h	5 Sep 2002 07:23:35 -0000	1.1
+++ linuxthreads/sysdeps/powerpc/powerpc32/pt-machine.h	17 Feb 2003 19:20:40 -0000
@@ -36,10 +36,36 @@ extern int __compare_and_swap (long int 
    need to make sure that the compiler has flushed everything to memory.  */
 #define MEMORY_BARRIER() __asm__ __volatile__ ("sync" : : : "memory")
 
+/* We want the OS to assign stack addresses.  */
+#define FLOATING_STACKS 1
+
+/* Maximum size of the stack if the rlimit is unlimited.  */
+#define ARCH_STACK_MAX_SIZE     8*1024*1024
+
 /* Get some notion of the current stack.  Need not be exactly the top
    of the stack, just something somewhere in the current frame.  */
 #define CURRENT_STACK_FRAME  stack_pointer
 register char * stack_pointer __asm__ ("r1");
+
+/* Register r2 (tp) is reserved by the ABI as "thread pointer". */
+struct _pthread_descr_struct;
+register struct _pthread_descr_struct *__thread_self __asm__("r2");
+
+/* Return the thread descriptor for the current thread.  */
+#define THREAD_SELF  __thread_self
+
+/* Initialize the thread-unique value.  */
+#define INIT_THREAD_SELF(descr, nr)  (__thread_self = (descr))
+
+/* Access to data in the thread descriptor is easy.  */
+#define THREAD_GETMEM(descr, member) \
+  ((void) (descr), THREAD_SELF->member)
+#define THREAD_GETMEM_NC(descr, member) \
+  ((void) (descr), THREAD_SELF->member)
+#define THREAD_SETMEM(descr, member, value) \
+  ((void) (descr), THREAD_SELF->member = (value))
+#define THREAD_SETMEM_NC(descr, member, value) \
+  ((void) (descr), THREAD_SELF->member = (value))
 
 /* Compare-and-swap for semaphores. */
 /* note that test-and-set(x) is the same as !compare-and-swap(x, 0, 1) */
Index: linuxthreads/sysdeps/unix/sysv/linux/powerpc/powerpc32/sysdep-cancel.h
===================================================================
RCS file: /cvs/glibc/libc/linuxthreads/sysdeps/unix/sysv/linux/powerpc/powerpc32/sysdep-cancel.h,v
retrieving revision 1.2
diff -u -p -r1.2 sysdep-cancel.h
--- linuxthreads/sysdeps/unix/sysv/linux/powerpc/powerpc32/sysdep-cancel.h	8 Jan 2003 06:45:06 -0000	1.2
+++ linuxthreads/sysdeps/unix/sysv/linux/powerpc/powerpc32/sysdep-cancel.h	17 Feb 2003 19:20:40 -0000
@@ -18,6 +18,7 @@
    02111-1307 USA.  */
 
 #include <sysdep.h>
+#include <tls.h>
 #ifndef __ASSEMBLER__
 # include <linuxthreads/internals.h>
 #endif
@@ -77,32 +78,19 @@
 # ifdef IS_IN_libpthread
 #  define CENABLE	bl JUMPTARGET(__pthread_enable_asynccancel)
 #  define CDISABLE	bl JUMPTARGET(__pthread_disable_asynccancel)
-#  define __local_multiple_threads __pthread_multiple_threads
 # else
 #  define CENABLE	bl JUMPTARGET(__libc_enable_asynccancel)
 #  define CDISABLE	bl JUMPTARGET(__libc_disable_asynccancel)
-#  define __local_multiple_threads __libc_multiple_threads
 # endif
 
 # ifndef __ASSEMBLER__
-extern int __local_multiple_threads attribute_hidden;
-#  define SINGLE_THREAD_P __builtin_expect (__local_multiple_threads == 0, 1)
+#  define SINGLE_THREAD_P						\
+  __builtin_expect (THREAD_GETMEM (THREAD_SELF,				\
+				     p_header.data.multiple_threads) == 0, 1)
 # else
-#  if !defined PIC
-#   define SINGLE_THREAD_P						\
-  lis 10,__local_multiple_threads@ha;					\
-  lwz 10,__local_multiple_threads@l(10);				\
+#  define SINGLE_THREAD_P						\
+  lwz 10,MULTIPLE_THREADS_OFFSET(2);					\
   cmpwi 10,0
-#  else
-#   define SINGLE_THREAD_P						\
-  mflr 9;								\
-  bl _GLOBAL_OFFSET_TABLE_@local-4;					\
-  mflr 10;								\
-  mtlr 9;								\
-  lwz 10,__local_multiple_threads@got(10);				\
-  lwz 10,0(10);								\
-  cmpwi 10,0
-#  endif
 # endif
 
 #elif !defined __ASSEMBLER__
Index: sysdeps/powerpc/elf/libc-start.c
===================================================================
RCS file: /cvs/glibc/libc/sysdeps/powerpc/elf/libc-start.c,v
retrieving revision 1.16
diff -u -p -r1.16 libc-start.c
--- sysdeps/powerpc/elf/libc-start.c	24 Oct 2002 19:13:38 -0000	1.16
+++ sysdeps/powerpc/elf/libc-start.c	17 Feb 2003 19:20:42 -0000
@@ -33,7 +33,7 @@ extern void *__libc_stack_end;
 #ifndef SHARED
 # include <tls.h>
 extern void __pthread_initialize_minimal (void)
-# if !(USE_TLS - 0)
+# if !(USE_TLS - 0) && !defined NONTLS_INIT_TP
      __attribute__ ((weak))
 # endif
      ;
@@ -134,7 +134,7 @@ BP_SYM (__libc_start_main) (int argc, ch
      we need to setup errno.  If there is no thread library and we
      handle TLS the function is defined in the libc to initialized the
      TLS handling.  */
-# if !(USE_TLS - 0)
+# if !(USE_TLS - 0) && !defined NONTLS_INIT_TP
   if (__pthread_initialize_minimal)
 # endif
     __pthread_initialize_minimal ();
Index: sysdeps/powerpc/powerpc32/__longjmp.S
===================================================================
RCS file: /cvs/glibc/libc/sysdeps/powerpc/powerpc32/__longjmp.S,v
retrieving revision 1.1
diff -u -p -r1.1 __longjmp.S
--- sysdeps/powerpc/powerpc32/__longjmp.S	5 Sep 2002 08:22:20 -0000	1.1
+++ sysdeps/powerpc/powerpc32/__longjmp.S	17 Feb 2003 19:20:42 -0000
@@ -28,7 +28,6 @@ ENTRY (BP_SYM (__longjmp))
 	CHECK_BOUNDS_BOTH_WIDE_LIT (r3, r8, r9, JB_SIZE)
 
 	lwz r1,(JB_GPR1*4)(r3)
-	lwz r2,(JB_GPR2*4)(r3)
 	lwz r0,(JB_LR*4)(r3)
 	lwz r14,((JB_GPRS+0)*4)(r3)
 	lwz r15,((JB_GPRS+1)*4)(r3)
Index: sysdeps/powerpc/powerpc32/setjmp.S
===================================================================
RCS file: /cvs/glibc/libc/sysdeps/powerpc/powerpc32/setjmp.S,v
retrieving revision 1.1
diff -u -p -r1.1 setjmp.S
--- sysdeps/powerpc/powerpc32/setjmp.S	5 Sep 2002 08:26:02 -0000	1.1
+++ sysdeps/powerpc/powerpc32/setjmp.S	17 Feb 2003 19:20:42 -0000
@@ -29,7 +29,6 @@ ENTRY (BP_SYM (__sigsetjmp))
 
 	stw  r1,(JB_GPR1*4)(3)
 	mflr r0
-	stw  r2,(JB_GPR2*4)(3)
 	stw  r14,((JB_GPRS+0)*4)(3)
 	stw  r0,(JB_LR*4)(3)
 	stw  r15,((JB_GPRS+1)*4)(3)
Index: sysdeps/powerpc/powerpc32/fpu/__longjmp.S
===================================================================
RCS file: /cvs/glibc/libc/sysdeps/powerpc/powerpc32/fpu/__longjmp.S,v
retrieving revision 1.1
diff -u -p -r1.1 __longjmp.S
--- sysdeps/powerpc/powerpc32/fpu/__longjmp.S	5 Sep 2002 08:58:45 -0000	1.1
+++ sysdeps/powerpc/powerpc32/fpu/__longjmp.S	17 Feb 2003 19:20:42 -0000
@@ -28,7 +28,6 @@ ENTRY (BP_SYM (__longjmp))
 	CHECK_BOUNDS_BOTH_WIDE_LIT (r3, r8, r9, JB_SIZE)
 
 	lwz r1,(JB_GPR1*4)(r3)
-	lwz r2,(JB_GPR2*4)(r3)
 	lwz r0,(JB_LR*4)(r3)
 	lwz r14,((JB_GPRS+0)*4)(r3)
 	lfd fp14,((JB_FPRS+0*2)*4)(r3)
Index: sysdeps/powerpc/powerpc32/fpu/setjmp.S
===================================================================
RCS file: /cvs/glibc/libc/sysdeps/powerpc/powerpc32/fpu/setjmp.S,v
retrieving revision 1.1
diff -u -p -r1.1 setjmp.S
--- sysdeps/powerpc/powerpc32/fpu/setjmp.S	5 Sep 2002 09:00:00 -0000	1.1
+++ sysdeps/powerpc/powerpc32/fpu/setjmp.S	17 Feb 2003 19:20:42 -0000
@@ -29,7 +29,6 @@ ENTRY (BP_SYM (__sigsetjmp))
 
 	stw  r1,(JB_GPR1*4)(3)
 	mflr r0
-	stw  r2,(JB_GPR2*4)(3)
 	stw  r14,((JB_GPRS+0)*4)(3)
 	stfd fp14,((JB_FPRS+0*2)*4)(3)
 	stw  r0,(JB_LR*4)(3)
--- /dev/null	2002-11-11 17:51:46.000000000 -0700
+++ linuxthreads/sysdeps/powerpc/tcb-offsets.sym	2003-01-08 13:34:54.000000000 -0700
@@ -0,0 +1,4 @@
+#include <sysdep.h>
+#include <tls.h>
+
+MULTIPLE_THREADS_OFFSET		offsetof (tcbhead_t, multiple_threads)
--- /dev/null	2002-11-11 17:51:46.000000000 -0700
+++ linuxthreads/sysdeps/powerpc/tls.h	2003-01-09 16:06:24.000000000 -0700
@@ -0,0 +1,63 @@
+/* Definitions for thread-local data handling.  linuxthreads/PPC version.
+   Copyright (C) 2003 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, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#ifndef _TLS_H
+#define _TLS_H
+
+#ifndef __ASSEMBLER__
+
+# include <pt-machine.h>
+# include <stddef.h>
+
+/* Type for the dtv.  */
+typedef union dtv
+{
+  size_t counter;
+  void *pointer;
+} dtv_t;
+
+typedef struct
+{
+  void *tcb;		/* Pointer to the TCB.  Not necessary the
+			   thread descriptor used by libpthread.  */
+  dtv_t *dtv;
+  void *self;		/* Pointer to the thread descriptor.  */
+  int multiple_threads;
+} tcbhead_t;
+
+#else /* __ASSEMBLER__ */
+# include <tcb-offsets.h>
+#endif /* __ASSEMBLER__ */
+
+#undef USE_TLS
+
+#if USE_TLS
+
+#else
+
+#define NONTLS_INIT_TP							\
+  do {									\
+    static const tcbhead_t nontls_init_tp				\
+      = { .multiple_threads = 0 };					\
+    __thread_self = (__typeof (__thread_self)) &nontls_init_tp;		\
+  } while (0)
+
+#endif /* USE_TLS */
+
+#endif	/* tls.h */


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