sparc specific bits needed for nptl

 * a tweaked clone.S with RESET_PID support
 * atomic.h with cmpxchg that works for v8 and beyond

Signed-off-by: Austin Foxley <austinf@cetoncorp.com>

1 files changed, 329 insertions, 0 deletions

diff --git a/libc/sysdeps/linux/sparc/bits/atomic.h b/libc/sysdeps/linux/sparc/bits/atomic.h
new file mode 100644
index 000000000..f625eb92a
--- /dev/null
+++ b/libc/sysdeps/linux/sparc/bits/atomic.h
@@ -0,0 +1,329 @@
+/* Atomic operations.  sparc32 version.
+   Copyright (C) 2003, 2004, 2006 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Jakub Jelinek <jakub@redhat.com>, 2003.
+
+   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 _BITS_ATOMIC_H
+#define _BITS_ATOMIC_H	1
+
+#include <stdint.h>
+
+typedef int8_t atomic8_t;
+typedef uint8_t uatomic8_t;
+typedef int_fast8_t atomic_fast8_t;
+typedef uint_fast8_t uatomic_fast8_t;
+
+typedef int16_t atomic16_t;
+typedef uint16_t uatomic16_t;
+typedef int_fast16_t atomic_fast16_t;
+typedef uint_fast16_t uatomic_fast16_t;
+
+typedef int32_t atomic32_t;
+typedef uint32_t uatomic32_t;
+typedef int_fast32_t atomic_fast32_t;
+typedef uint_fast32_t uatomic_fast32_t;
+
+typedef int64_t atomic64_t;
+typedef uint64_t uatomic64_t;
+typedef int_fast64_t atomic_fast64_t;
+typedef uint_fast64_t uatomic_fast64_t;
+
+typedef intptr_t atomicptr_t;
+typedef uintptr_t uatomicptr_t;
+typedef intmax_t atomic_max_t;
+typedef uintmax_t uatomic_max_t;
+
+
+/* We have no compare and swap, just test and set.
+   The following implementation contends on 64 global locks
+   per library and assumes no variable will be accessed using atomic.h
+   macros from two different libraries.  */
+
+__make_section_unallocated
+  (".gnu.linkonce.b.__sparc32_atomic_locks, \"aw\", %nobits");
+
+volatile unsigned char __sparc32_atomic_locks[64]
+  __attribute__ ((nocommon, section (".gnu.linkonce.b.__sparc32_atomic_locks"
+				     __sec_comment),
+		  visibility ("hidden")));
+
+#define __sparc32_atomic_do_lock(addr) \
+  do								      \
+    {								      \
+      unsigned int __old_lock;					      \
+      unsigned int __idx = (((long) addr >> 2) ^ ((long) addr >> 12)) \
+			   & 63;				      \
+      do							      \
+	__asm __volatile ("ldstub %1, %0"			      \
+			  : "=r" (__old_lock),			      \
+			    "=m" (__sparc32_atomic_locks[__idx])      \
+			  : "m" (__sparc32_atomic_locks[__idx])	      \
+			  : "memory");				      \
+      while (__old_lock);					      \
+    }								      \
+  while (0)
+
+#define __sparc32_atomic_do_unlock(addr) \
+  do								      \
+    {								      \
+      __sparc32_atomic_locks[(((long) addr >> 2)		      \
+			      ^ ((long) addr >> 12)) & 63] = 0;	      \
+      __asm __volatile ("" ::: "memory");			      \
+    }								      \
+  while (0)
+
+#define __sparc32_atomic_do_lock24(addr) \
+  do								      \
+    {								      \
+      unsigned int __old_lock;					      \
+      do							      \
+	__asm __volatile ("ldstub %1, %0"			      \
+			  : "=r" (__old_lock), "=m" (*(addr))	      \
+			  : "m" (*(addr))			      \
+			  : "memory");				      \
+      while (__old_lock);					      \
+    }								      \
+  while (0)
+
+#define __sparc32_atomic_do_unlock24(addr) \
+  do								      \
+    {								      \
+      *(char *) (addr) = 0;					      \
+      __asm __volatile ("" ::: "memory");			      \
+    }								      \
+  while (0)
+
+
+#ifndef SHARED
+# define __v9_compare_and_exchange_val_32_acq(mem, newval, oldval) \
+({									      \
+  register __typeof (*(mem)) __acev_tmp __asm ("%g6");			      \
+  register __typeof (mem) __acev_mem __asm ("%g1") = (mem);		      \
+  register __typeof (*(mem)) __acev_oldval __asm ("%g5");		      \
+  __acev_tmp = (newval);						      \
+  __acev_oldval = (oldval);						      \
+  /* .word 0xcde05005 is cas [%g1], %g5, %g6.  Can't use cas here though,     \
+     because as will then mark the object file as V8+ arch.  */		      \
+  __asm __volatile (".word 0xcde05005"					      \
+		    : "+r" (__acev_tmp), "=m" (*__acev_mem)		      \
+		    : "r" (__acev_oldval), "m" (*__acev_mem),		      \
+		      "r" (__acev_mem) : "memory");			      \
+  __acev_tmp; })
+#endif
+
+/* The only basic operation needed is compare and exchange.  */
+#define __v7_compare_and_exchange_val_acq(mem, newval, oldval) \
+  ({ __typeof (mem) __acev_memp = (mem);			      \
+     __typeof (*mem) __acev_ret;				      \
+     __typeof (*mem) __acev_newval = (newval);			      \
+								      \
+     __sparc32_atomic_do_lock (__acev_memp);			      \
+     __acev_ret = *__acev_memp;					      \
+     if (__acev_ret == (oldval))				      \
+       *__acev_memp = __acev_newval;				      \
+     __sparc32_atomic_do_unlock (__acev_memp);			      \
+     __acev_ret; })
+
+#define __v7_compare_and_exchange_bool_acq(mem, newval, oldval) \
+  ({ __typeof (mem) __aceb_memp = (mem);			      \
+     int __aceb_ret;						      \
+     __typeof (*mem) __aceb_newval = (newval);			      \
+								      \
+     __sparc32_atomic_do_lock (__aceb_memp);			      \
+     __aceb_ret = 0;						      \
+     if (*__aceb_memp == (oldval))				      \
+       *__aceb_memp = __aceb_newval;				      \
+     else							      \
+       __aceb_ret = 1;						      \
+     __sparc32_atomic_do_unlock (__aceb_memp);			      \
+     __aceb_ret; })
+
+#define __v7_exchange_acq(mem, newval) \
+  ({ __typeof (mem) __acev_memp = (mem);			      \
+     __typeof (*mem) __acev_ret;				      \
+     __typeof (*mem) __acev_newval = (newval);			      \
+								      \
+     __sparc32_atomic_do_lock (__acev_memp);			      \
+     __acev_ret = *__acev_memp;					      \
+     *__acev_memp = __acev_newval;				      \
+     __sparc32_atomic_do_unlock (__acev_memp);			      \
+     __acev_ret; })
+
+#define __v7_exchange_and_add(mem, value) \
+  ({ __typeof (mem) __acev_memp = (mem);			      \
+     __typeof (*mem) __acev_ret;				      \
+								      \
+     __sparc32_atomic_do_lock (__acev_memp);			      \
+     __acev_ret = *__acev_memp;					      \
+     *__acev_memp = __acev_ret + (value);			      \
+     __sparc32_atomic_do_unlock (__acev_memp);			      \
+     __acev_ret; })
+
+/* Special versions, which guarantee that top 8 bits of all values
+   are cleared and use those bits as the ldstub lock.  */
+#define __v7_compare_and_exchange_val_24_acq(mem, newval, oldval) \
+  ({ __typeof (mem) __acev_memp = (mem);			      \
+     __typeof (*mem) __acev_ret;				      \
+     __typeof (*mem) __acev_newval = (newval);			      \
+								      \
+     __sparc32_atomic_do_lock24 (__acev_memp);			      \
+     __acev_ret = *__acev_memp & 0xffffff;			      \
+     if (__acev_ret == (oldval))				      \
+       *__acev_memp = __acev_newval;				      \
+     else							      \
+       __sparc32_atomic_do_unlock24 (__acev_memp);		      \
+     __asm __volatile ("" ::: "memory");			      \
+     __acev_ret; })
+
+#define __v7_exchange_24_rel(mem, newval) \
+  ({ __typeof (mem) __acev_memp = (mem);			      \
+     __typeof (*mem) __acev_ret;				      \
+     __typeof (*mem) __acev_newval = (newval);			      \
+								      \
+     __sparc32_atomic_do_lock24 (__acev_memp);			      \
+     __acev_ret = *__acev_memp & 0xffffff;			      \
+     *__acev_memp = __acev_newval;				      \
+     __asm __volatile ("" ::: "memory");			      \
+     __acev_ret; })
+
+#ifdef SHARED
+
+/* When dynamically linked, we assume pre-v9 libraries are only ever
+   used on pre-v9 CPU.  */
+# define __atomic_is_v9 0
+
+# define atomic_compare_and_exchange_val_acq(mem, newval, oldval) \
+  __v7_compare_and_exchange_val_acq (mem, newval, oldval)
+
+# define atomic_compare_and_exchange_bool_acq(mem, newval, oldval) \
+  __v7_compare_and_exchange_bool_acq (mem, newval, oldval)
+
+# define atomic_exchange_acq(mem, newval) \
+  __v7_exchange_acq (mem, newval)
+
+# define atomic_exchange_and_add(mem, value) \
+  __v7_exchange_and_add (mem, value)
+
+# define atomic_compare_and_exchange_val_24_acq(mem, newval, oldval) \
+  ({								      \
+     if (sizeof (*mem) != 4)					      \
+       abort ();						      \
+     __v7_compare_and_exchange_val_24_acq (mem, newval, oldval); })
+
+# define atomic_exchange_24_rel(mem, newval) \
+  ({								      \
+     if (sizeof (*mem) != 4)					      \
+       abort ();						      \
+     __v7_exchange_24_rel (mem, newval); })
+
+#else
+
+
+
+/*
+   Here's what we'd like to do:
+
+   In libc.a/libpthread.a etc. we don't know if we'll be run on
+   pre-v9 or v9 CPU.  To be interoperable with dynamically linked
+   apps on v9 CPUs e.g. with process shared primitives, use cas insn
+   on v9 CPUs and ldstub on pre-v9.
+
+   However, we have no good way to test at run time that I know of,
+   so resort to the lowest common denominator (v7 ops) -austinf
+ */
+#define __atomic_is_v9 0
+
+# define atomic_compare_and_exchange_val_acq(mem, newval, oldval) \
+  ({								      \
+     __typeof (*mem) __acev_wret;				      \
+     if (sizeof (*mem) != 4)					      \
+       abort ();						      \
+     if (__atomic_is_v9)					      \
+       __acev_wret						      \
+	 = __v9_compare_and_exchange_val_32_acq (mem, newval, oldval);\
+     else							      \
+       __acev_wret						      \
+	 = __v7_compare_and_exchange_val_acq (mem, newval, oldval);   \
+     __acev_wret; })
+
+# define atomic_compare_and_exchange_bool_acq(mem, newval, oldval) \
+  ({								      \
+     int __acev_wret;						      \
+     if (sizeof (*mem) != 4)					      \
+       abort ();						      \
+     if (__atomic_is_v9)					      \
+       {							      \
+	 __typeof (oldval) __acev_woldval = (oldval);		      \
+	 __acev_wret						      \
+	   = __v9_compare_and_exchange_val_32_acq (mem, newval,	      \
+						   __acev_woldval)    \
+	     != __acev_woldval;					      \
+       }							      \
+     else							      \
+       __acev_wret						      \
+	 = __v7_compare_and_exchange_bool_acq (mem, newval, oldval);  \
+     __acev_wret; })
+
+# define atomic_exchange_rel(mem, newval) \
+  ({								      \
+     __typeof (*mem) __acev_wret;				      \
+     if (sizeof (*mem) != 4)					      \
+       abort ();						      \
+     if (__atomic_is_v9)					      \
+       {							      \
+	 __typeof (mem) __acev_wmemp = (mem);			      \
+	 __typeof (*(mem)) __acev_wval = (newval);		      \
+	 do							      \
+	   __acev_wret = *__acev_wmemp;				      \
+	 while (__builtin_expect				      \
+		  (__v9_compare_and_exchange_val_32_acq (__acev_wmemp,\
+							 __acev_wval, \
+							 __acev_wret) \
+		   != __acev_wret, 0));				      \
+       }							      \
+     else							      \
+       __acev_wret = __v7_exchange_acq (mem, newval);		      \
+     __acev_wret; })
+
+# define atomic_compare_and_exchange_val_24_acq(mem, newval, oldval) \
+  ({								      \
+     __typeof (*mem) __acev_wret;				      \
+     if (sizeof (*mem) != 4)					      \
+       abort ();						      \
+     if (__atomic_is_v9)					      \
+       __acev_wret						      \
+	 = __v9_compare_and_exchange_val_32_acq (mem, newval, oldval);\
+     else							      \
+       __acev_wret						      \
+	 = __v7_compare_and_exchange_val_24_acq (mem, newval, oldval);\
+     __acev_wret; })
+
+# define atomic_exchange_24_rel(mem, newval) \
+  ({								      \
+     __typeof (*mem) __acev_w24ret;				      \
+     if (sizeof (*mem) != 4)					      \
+       abort ();						      \
+     if (__atomic_is_v9)					      \
+       __acev_w24ret = atomic_exchange_rel (mem, newval);	      \
+     else							      \
+       __acev_w24ret = __v7_exchange_24_rel (mem, newval);	      \
+     __acev_w24ret; })
+
+#endif
+
+#endif	/* bits/atomic.h */