Patchwork [RFC,v3,05/12] C-SKY: Atomic and Locking Routines

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Submitter Mao Han
Date June 29, 2018, 7:58 a.m.
Message ID <52862eb735de64be1bd5a61b21ef9585e665558d.1530246556.git.han_mao@c-sky.com>
Download mbox | patch
Permalink /patch/28122/
State New
Headers show

Comments

Mao Han - June 29, 2018, 7:58 a.m.
This patch implements various atomic and locking routines on C-SKY.

	* sysdeps/csky/atomic-machine.h: New file.
	* sysdeps/csky/nptl/bits/pthreadtypes-arch.h: Likewise.
	* sysdeps/csky/nptl/bits/semaphore.h: Likewise.
---
 sysdeps/csky/atomic-machine.h              | 97 ++++++++++++++++++++++++++++++
 sysdeps/csky/nptl/bits/pthreadtypes-arch.h | 70 +++++++++++++++++++++
 sysdeps/csky/nptl/bits/semaphore.h         | 35 +++++++++++
 3 files changed, 202 insertions(+)
 create mode 100644 sysdeps/csky/atomic-machine.h
 create mode 100644 sysdeps/csky/nptl/bits/pthreadtypes-arch.h
 create mode 100644 sysdeps/csky/nptl/bits/semaphore.h
Joseph Myers - June 29, 2018, 4:36 p.m.
On Fri, 29 Jun 2018, Mao Han wrote:

> +#define USE_ATOMIC_COMPILER_BUILTINS 0

Does this mean the compiler expands the atomic built-in function calls to 
out-of-line calls to libgcc or libatomic, but you wish to use inline 
expansions in glibc?  (That's the main case when 
USE_ATOMIC_COMPILER_BUILTINS 0 is appropriate.  If there are suitable 
atomic instructions, typically the compiler would expand the calls inline 
and USE_ATOMIC_COMPILER_BUILTINS 1 is most appropriate rather than using 
inline asm for atomics.)
Mao Han - July 3, 2018, 7:56 a.m.
On Fri, Jun 29, 2018 at 04:36:19PM +0000, Joseph Myers wrote:
> On Fri, 29 Jun 2018, Mao Han wrote:
> 
> > +#define USE_ATOMIC_COMPILER_BUILTINS 0
> 
> Does this mean the compiler expands the atomic built-in function calls to 
> out-of-line calls to libgcc or libatomic, but you wish to use inline 
> expansions in glibc?  (That's the main case when 
> USE_ATOMIC_COMPILER_BUILTINS 0 is appropriate.  If there are suitable 
> atomic instructions, typically the compiler would expand the calls inline 
> and USE_ATOMIC_COMPILER_BUILTINS 1 is most appropriate rather than using 
> inline asm for atomics.)
> 
> -- 
> Joseph S. Myers
> joseph@codesourcery.com
Thanks a lot for the feedfack.
The macro seems someting to reduce architecture-specific code
needed to support C11-like atomics? If compiler can expands the
atomic built-in to the correct call, either libgcc or libatomic(inline)
, it is suggested to define USE_ATOMIC_COMPILER_BUILTINS to 1?
I don't know what will the difference between out-of-line call and
inline call affect on the linux system. effciency?
I'm also not sure about the macro ATOMIC_EXCHANGE_USES_CAS.
We don't have any exchange instruction.
We've only got CAS loop implement with linux helper on ck807/ck810 in libgcc,
and one implement with load-store Exclusive on ck860.
According to comment in pthread_spin_trylock.c ATOMIC_EXCHANGE_USES_CAS
should define to 1 if exchange is not supported? I did not found any
difference while running testsuits.
Is it better to have the atomic-machine.h like this below?

#define __HAVE_64B_ATOMICS 0
#define USE_ATOMIC_COMPILER_BUILTINS 1
#define ATOMIC_EXCHANGE_USES_CAS 1

#define __arch_compare_and_exchange_bool_8_int(mem, newval, oldval, model) \
  (abort (), 0)

#define __arch_compare_and_exchange_bool_16_int(mem, newval, oldval, model) \
  (abort (), 0)

#define __arch_compare_and_exchange_bool_32_int(mem, newval, oldval, model) \
  ({                                                                    \
    typeof (*mem) __oldval = (oldval);                                  \
    !__atomic_compare_exchange_n (mem, (void *) &__oldval, newval, 0,   \
                                  model, __ATOMIC_RELAXED);             \
  })
#define __arch_compare_and_exchange_bool_64_int(mem, newval, oldval, model) \
  (abort (), 0)

#define __arch_compare_and_exchange_val_8_int(mem, newval, oldval, model) \
  (abort (), (__typeof (*mem)) 0)

#define __arch_compare_and_exchange_val_16_int(mem, newval, oldval, model) \
  (abort (), (__typeof (*mem)) 0)

#define __arch_compare_and_exchange_val_32_int(mem, newval, oldval, model) \
  ({                                                                    \
    typeof (*mem) __oldval = (oldval);                                  \
    __atomic_compare_exchange_n (mem, (void *) &__oldval, newval, 0,    \
                                 model, __ATOMIC_RELAXED);              \
    __oldval;                                                           \
  })

#define __arch_compare_and_exchange_val_64_int(mem, newval, oldval, model) \
  (abort (), (__typeof (*mem)) 0)

#define atomic_compare_and_exchange_bool_acq(mem, new, old)             \
  __atomic_bool_bysize (__arch_compare_and_exchange_bool, int,          \
                        mem, new, old, __ATOMIC_ACQUIRE)

#define atomic_compare_and_exchange_val_acq(mem, new, old)              \
  __atomic_val_bysize (__arch_compare_and_exchange_val, int,            \
                       mem, new, old, __ATOMIC_ACQUIRE)

Patch

diff --git a/sysdeps/csky/atomic-machine.h b/sysdeps/csky/atomic-machine.h
new file mode 100644
index 0000000..b64674f
--- /dev/null
+++ b/sysdeps/csky/atomic-machine.h
@@ -0,0 +1,97 @@ 
+/* Atomic operations.  C-SKY version.
+   Copyright (C) 2018 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
+   <http://www.gnu.org/licenses/>.  */
+
+#ifndef __CSKY_ATOMIC_H_
+#define __CSKY_ATOMIC_H_
+
+#include <stdint.h>
+
+typedef int32_t atomic32_t;
+typedef uint32_t uatomic32_t;
+
+typedef intptr_t atomicptr_t;
+typedef uintptr_t uatomicptr_t;
+typedef intmax_t atomic_max_t;
+typedef uintmax_t uatomic_max_t;
+
+#define __HAVE_64B_ATOMICS 0
+#define USE_ATOMIC_COMPILER_BUILTINS 0
+#define ATOMIC_EXCHANGE_USES_CAS 0
+
+#define __arch_compare_and_exchange_bool_8_int(mem, newval, oldval)	\
+  (abort (), 0)
+
+#define __arch_compare_and_exchange_bool_16_int(mem, newval, oldval)	\
+  (abort (), 0)
+
+#define __arch_compare_and_exchange_bool_32_int(mem, newval, oldval)	\
+  ({ __typeof (mem) _mem = (mem);					\
+     __typeof (oldval) _oldval = oldval;				\
+     __typeof (newval) _newval = newval;				\
+     register int _a0 asm ("a0") = (int)_oldval;			\
+     register int _a1 asm ("a1") = (int)_newval;			\
+     register int _a2 asm ("a2") = (int)_mem;				\
+     __asm__ __volatile__ ("trap   2"					\
+			   : "+r" (_a0) : "r" (_a1) , "r" (_a2)		\
+			   : "a3", "memory");				\
+     (int) _a0; })
+
+#define __arch_compare_and_exchange_bool_64_int(mem, newval, oldval)	\
+  (abort (), 0)
+
+#define __arch_compare_and_exchange_val_8_int(mem, newval, oldval)	\
+  (abort (), (__typeof (*mem)) 0)
+
+#define __arch_compare_and_exchange_val_16_int(mem, newval, oldval)	\
+  (abort (), (__typeof (*mem)) 0)
+
+#define __arch_compare_and_exchange_val_32_int(mem, newval, oldval)	\
+  ({ __typeof (mem) _mem = (mem);					\
+     __typeof (*mem) __gret = *_mem;					\
+     unsigned int _tmp = 0;						\
+     __typeof (oldval) _oldval = oldval;				\
+     __typeof (newval) _newval = newval;				\
+     register int _a0 asm ("a0") = (int)_oldval;			\
+     register int _a1 asm ("a1") = (int)_newval;			\
+     register int _a2 asm ("a2") = (int)_mem;				\
+     __asm__ __volatile__ ("1:\tldw %1, (%4, 0x0)\n\t"			\
+			   "cmpne %1, %0\n\t"				\
+			   "bt 2f\n\t"					\
+			   "mov %2, %0\n\t"				\
+			   "trap 2\n\t"					\
+			   "cmpnei %0, 0\n\t"				\
+			   "mov %0, %2\n\t"				\
+			   "bt 1b\n"					\
+			   "2:"						\
+			   : "+r" (_a0), "+r"(__gret), "+r" (_tmp)	\
+			   : "r" (_a1) , "r" (_a2)			\
+			   : "a3", "memory");				\
+     __gret; })
+
+#define __arch_compare_and_exchange_val_64_int(mem, newval, oldval)	\
+  (abort (), (__typeof (*mem)) 0)
+
+#define atomic_compare_and_exchange_bool_acq(mem, new, old)		\
+  __atomic_bool_bysize (__arch_compare_and_exchange_bool, int,		\
+			mem, new, old)
+
+#define atomic_compare_and_exchange_val_acq(mem, new, old)		\
+  __atomic_val_bysize (__arch_compare_and_exchange_val, int,		\
+		       mem, new, old)
+
+#endif /* atomic-machine.h */
diff --git a/sysdeps/csky/nptl/bits/pthreadtypes-arch.h b/sysdeps/csky/nptl/bits/pthreadtypes-arch.h
new file mode 100644
index 0000000..d3423fb
--- /dev/null
+++ b/sysdeps/csky/nptl/bits/pthreadtypes-arch.h
@@ -0,0 +1,70 @@ 
+/* Machine-specific pthread type layouts.  C-SKY version.
+   Copyright (C) 2018 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
+   <http://www.gnu.org/licenses/>.  */
+
+#ifndef _BITS_PTHREADTYPES_ARCH_H
+#define _BITS_PTHREADTYPES_ARCH_H	1
+
+#include <endian.h>
+
+#define __SIZEOF_PTHREAD_ATTR_T			36
+#define __SIZEOF_PTHREAD_MUTEX_T		24
+#define __SIZEOF_PTHREAD_MUTEXATTR_T		4
+#define __SIZEOF_PTHREAD_COND_T			48
+#define __SIZEOF_PTHREAD_CONDATTR_T		4
+#define __SIZEOF_PTHREAD_RWLOCK_T		32
+#define __SIZEOF_PTHREAD_RWLOCKATTR_T		8
+#define __SIZEOF_PTHREAD_BARRIER_T		20
+#define __SIZEOF_PTHREAD_BARRIERATTR_T		4
+
+/* Data structure for mutex handling. */
+#define __PTHREAD_COMPAT_PADDING_MID
+#define __PTHREAD_COMPAT_PADDING_END
+#define __PTHREAD_MUTEX_LOCK_ELISION		0
+#define __PTHREAD_MUTEX_NUSERS_AFTER_KIND	1
+#define __PTHREAD_MUTEX_USE_UNION		1
+
+#define __LOCK_ALIGNMENT
+#define __ONCE_ALIGNMENT
+
+/* Paddings in this structure are not strictly necessary on C-SKY.
+   They are left for extensibility as most other architecture do so.  */
+struct __pthread_rwlock_arch_t
+{
+  unsigned int __readers;
+  unsigned int __writers;
+  unsigned int __wrphase_futex;
+  unsigned int __writers_futex;
+  unsigned int __pad3;
+  unsigned int __pad4;
+#if __BYTE_ORDER == __BIG_ENDIAN
+  unsigned char __pad1;
+  unsigned char __pad2;
+  unsigned char __shared;
+  unsigned char __flags;
+#else
+  unsigned char __flags;
+  unsigned char __shared;
+  unsigned char __pad1;
+  unsigned char __pad2;
+#endif
+  int __cur_writer;
+};
+
+#define __PTHREAD_RWLOCK_ELISION_EXTRA 0
+
+#endif
diff --git a/sysdeps/csky/nptl/bits/semaphore.h b/sysdeps/csky/nptl/bits/semaphore.h
new file mode 100644
index 0000000..0b13f59
--- /dev/null
+++ b/sysdeps/csky/nptl/bits/semaphore.h
@@ -0,0 +1,35 @@ 
+/* Machine-specific POSIX semaphore type layouts.  C-SKY version.
+   Copyright (C) 2018 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
+   <http://www.gnu.org/licenses/>.  */
+
+#ifndef _SEMAPHORE_H
+# error "Never use <bits/semaphore.h> directly; include <semaphore.h> instead."
+#endif
+
+
+#define __SIZEOF_SEM_T	16
+
+
+/* Value returned if `sem_open' failed.  */
+#define SEM_FAILED	((sem_t *) 0)
+
+
+typedef union
+{
+  char __size[__SIZEOF_SEM_T];
+  long int __align;
+} sem_t;