[thirdparty/glibc.git] / sysdeps / unix / sysv / linux / s390 / htm.h

/* Shared HTM header.  Work around false transactional execution facility
   intrinsics.

   Copyright (C) 2016-2017 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 _HTM_H
#define _HTM_H 1

#include <htmintrin.h>

#ifdef __s390x__
# define TX_FPRS_BYTES 64
# define TX_SAVE_FPRS						\
  "   std %%f8, 0(%[R_FPRS])\n\t"				\
  "   std %%f9, 8(%[R_FPRS])\n\t"				\
  "   std %%f10, 16(%[R_FPRS])\n\t"				\
  "   std %%f11, 24(%[R_FPRS])\n\t"				\
  "   std %%f12, 32(%[R_FPRS])\n\t"				\
  "   std %%f13, 40(%[R_FPRS])\n\t"				\
  "   std %%f14, 48(%[R_FPRS])\n\t"				\
  "   std %%f15, 56(%[R_FPRS])\n\t"

# define TX_RESTORE_FPRS					\
  "   ld %%f8, 0(%[R_FPRS])\n\t"				\
  "   ld %%f9, 8(%[R_FPRS])\n\t"				\
  "   ld %%f10, 16(%[R_FPRS])\n\t"				\
  "   ld %%f11, 24(%[R_FPRS])\n\t"				\
  "   ld %%f12, 32(%[R_FPRS])\n\t"				\
  "   ld %%f13, 40(%[R_FPRS])\n\t"				\
  "   ld %%f14, 48(%[R_FPRS])\n\t"				\
  "   ld %%f15, 56(%[R_FPRS])\n\t"

#else

# define TX_FPRS_BYTES 16
# define TX_SAVE_FPRS						\
  "   std %%f4, 0(%[R_FPRS])\n\t"				\
  "   std %%f6, 8(%[R_FPRS])\n\t"

# define TX_RESTORE_FPRS					\
  "   ld %%f4, 0(%[R_FPRS])\n\t"				\
  "   ld %%f6, 8(%[R_FPRS])\n\t"

#endif /* ! __s390x__  */

/* Use own inline assembly instead of __builtin_tbegin, as tbegin
   has to filter program interruptions which can't be done with the builtin.
   Now the fprs have to be saved / restored here, too.
   The fpc is also not saved / restored with the builtin.
   The used inline assembly does not clobber the volatile fprs / vrs!
   Clobbering the latter ones would force the compiler to save / restore
   the call saved fprs as those overlap with the vrs, but they only need to be
   restored if the transaction fails but not if the transaction is successfully
   started.  Thus the user of the tbegin macros in this header file has to
   compile the file / function with -msoft-float.  It prevents gcc from using
   fprs / vrs.  */
#define __libc_tbegin(tdb) __libc_tbegin_base(tdb,,,)

#define __libc_tbegin_retry_output_regs , [R_TX_CNT] "+&d" (__tx_cnt)
#define __libc_tbegin_retry_input_regs(retry_cnt) , [R_RETRY] "d" (retry_cnt)
#define __libc_tbegin_retry_abort_path_insn				\
  /* If tbegin returned _HTM_TBEGIN_TRANSIENT, retry immediately so	\
     that max tbegin_cnt transactions are tried.  Otherwise return and	\
     let the caller of this macro do the fallback path.  */		\
  "   jnh 1f\n\t" /* cc 1/3: jump to fallback path.  */			\
  /* tbegin returned _HTM_TBEGIN_TRANSIENT: retry with transaction.  */ \
  "   crje %[R_TX_CNT], %[R_RETRY], 1f\n\t" /* Reached max retries?  */	\
  "   ahi %[R_TX_CNT], 1\n\t"						\
  "   ppa %[R_TX_CNT], 0, 1\n\t" /* Transaction-Abort Assist.  */	\
  "   j 2b\n\t" /* Loop to tbegin.  */

/* Same as __libc_tbegin except if tbegin aborts with _HTM_TBEGIN_TRANSIENT.
   Then this macros restores the fpc, fprs and automatically retries up to
   retry_cnt tbegins.  Further saving of the state is omitted as it is already
   saved.  This macro calls tbegin at most as retry_cnt + 1 times.  */
#define __libc_tbegin_retry(tdb, retry_cnt)				\
  ({ int __ret;								\
    int __tx_cnt = 0;							\
    __ret = __libc_tbegin_base(tdb,					\
			       __libc_tbegin_retry_abort_path_insn,	\
			       __libc_tbegin_retry_output_regs,		\
			       __libc_tbegin_retry_input_regs(retry_cnt)); \
    __ret;								\
  })

#define __libc_tbegin_base(tdb, abort_path_insn, output_regs, input_regs) \
  ({ int __ret;								\
     int __fpc;								\
     char __fprs[TX_FPRS_BYTES];					\
     __asm__ __volatile__ (".machine push\n\t"				\
			   ".machinemode \"zarch_nohighgprs\"\n\t"	\
			   ".machine \"all\"\n\t"			\
			   /* Save state at the outermost transaction.	\
			      As extracting nesting depth is expensive	\
			      on at least zEC12, save fprs at inner	\
			      transactions, too.			\
			      The fpc and fprs are saved here as they	\
			      are not saved by tbegin.  There exist no	\
			      call-saved vrs, thus they are not saved	\
			      here.  */					\
			   "   efpc %[R_FPC]\n\t"			\
			   TX_SAVE_FPRS					\
			   /* Begin transaction: save all gprs, allow	\
			      ar modification and fp operations.  Some	\
			      program-interruptions (e.g. a null	\
			      pointer access) are filtered and the	\
			      trancsaction will abort.  In this case	\
			      the normal lock path will execute it	\
			      again and result in a core dump wich does	\
			      now show at tbegin but the real executed	\
			      instruction.  */				\
			   "2: tbegin 0, 0xFF0E\n\t"			\
			   /* Branch away in abort case (this is the	\
			      prefered sequence.  See PoP in chapter 5	\
			      Transactional-Execution Facility		\
			      Operation).  */				\
			   "   jnz 0f\n\t"				\
			   /* Transaction has successfully started.  */	\
			   "   lhi %[R_RET], 0\n\t"			\
			   "   j 1f\n\t"				\
			   /* Transaction has aborted.  Now we are at	\
			      the outermost transaction.  Restore fprs	\
			      and fpc. */				\
			   "0: ipm %[R_RET]\n\t"			\
			   "   srl %[R_RET], 28\n\t"			\
			   "   sfpc %[R_FPC]\n\t"			\
			   TX_RESTORE_FPRS				\
			   abort_path_insn				\
			   "1:\n\t"					\
			   ".machine pop\n"				\
			   : [R_RET] "=&d" (__ret),			\
			     [R_FPC] "=&d" (__fpc)			\
			     output_regs				\
			   : [R_FPRS] "a" (__fprs)			\
			     input_regs					\
			   : "cc", "memory");				\
     __ret;								\
     })

/* These builtins are correct.  Use them.  */
#define __libc_tend()							\
  ({ __asm__ __volatile__ (".machine push\n\t"				\
			   ".machinemode \"zarch_nohighgprs\"\n\t"	\
			   ".machine \"all\"\n\t");			\
    int __ret = __builtin_tend ();					\
    __asm__ __volatile__ (".machine pop");				\
    __ret;								\
  })

#define __libc_tabort(abortcode)					\
  __asm__ __volatile__ (".machine push\n\t"				\
			".machinemode \"zarch_nohighgprs\"\n\t"		\
			".machine \"all\"\n\t");			\
  __builtin_tabort (abortcode);						\
  __asm__ __volatile__ (".machine pop")

#define __libc_tx_nesting_depth() \
  ({ __asm__ __volatile__ (".machine push\n\t"				\
			   ".machinemode \"zarch_nohighgprs\"\n\t"	\
			   ".machine \"all\"\n\t");			\
    int __ret = __builtin_tx_nesting_depth ();				\
    __asm__ __volatile__ (".machine pop");				\
    __ret;								\
  })

#endif
Commit	Line	Data
8bfc4a2a SL	1	/* Shared HTM header. Work around false transactional execution facility
	2	intrinsics.
	3
bfff8b1b	4	Copyright (C) 2016-2017 Free Software Foundation, Inc.
8bfc4a2a SL	5	This file is part of the GNU C Library.
	6
	7	The GNU C Library is free software; you can redistribute it and/or
	8	modify it under the terms of the GNU Lesser General Public
	9	License as published by the Free Software Foundation; either
	10	version 2.1 of the License, or (at your option) any later version.
	11
	12	The GNU C Library is distributed in the hope that it will be useful,
	13	but WITHOUT ANY WARRANTY; without even the implied warranty of
	14	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	15	Lesser General Public License for more details.
	16
	17	You should have received a copy of the GNU Lesser General Public
	18	License along with the GNU C Library; if not, see
	19	<http://www.gnu.org/licenses/>. */
	20
	21	#ifndef _HTM_H
	22	#define _HTM_H 1
	23
	24	#include <htmintrin.h>
	25
	26	#ifdef __s390x__
	27	# define TX_FPRS_BYTES 64
	28	# define TX_SAVE_FPRS \
	29	" std %%f8, 0(%[R_FPRS])\n\t" \
	30	" std %%f9, 8(%[R_FPRS])\n\t" \
	31	" std %%f10, 16(%[R_FPRS])\n\t" \
	32	" std %%f11, 24(%[R_FPRS])\n\t" \
	33	" std %%f12, 32(%[R_FPRS])\n\t" \
	34	" std %%f13, 40(%[R_FPRS])\n\t" \
	35	" std %%f14, 48(%[R_FPRS])\n\t" \
	36	" std %%f15, 56(%[R_FPRS])\n\t"
	37
	38	# define TX_RESTORE_FPRS \
	39	" ld %%f8, 0(%[R_FPRS])\n\t" \
	40	" ld %%f9, 8(%[R_FPRS])\n\t" \
	41	" ld %%f10, 16(%[R_FPRS])\n\t" \
	42	" ld %%f11, 24(%[R_FPRS])\n\t" \
	43	" ld %%f12, 32(%[R_FPRS])\n\t" \
	44	" ld %%f13, 40(%[R_FPRS])\n\t" \
	45	" ld %%f14, 48(%[R_FPRS])\n\t" \
	46	" ld %%f15, 56(%[R_FPRS])\n\t"
	47
	48	#else
	49
	50	# define TX_FPRS_BYTES 16
	51	# define TX_SAVE_FPRS \
	52	" std %%f4, 0(%[R_FPRS])\n\t" \
	53	" std %%f6, 8(%[R_FPRS])\n\t"
	54
	55	# define TX_RESTORE_FPRS \
	56	" ld %%f4, 0(%[R_FPRS])\n\t" \
	57	" ld %%f6, 8(%[R_FPRS])\n\t"
	58
	59	#endif /* ! __s390x__ */
	60
	61	/* Use own inline assembly instead of __builtin_tbegin, as tbegin
	62	has to filter program interruptions which can't be done with the builtin.
	63	Now the fprs have to be saved / restored here, too.
	64	The fpc is also not saved / restored with the builtin.
	65	The used inline assembly does not clobber the volatile fprs / vrs!
	66	Clobbering the latter ones would force the compiler to save / restore
	67	the call saved fprs as those overlap with the vrs, but they only need to be
	68	restored if the transaction fails but not if the transaction is successfully
69	started. Thus the user of the tbegin macros in this header file has to
70	compile the file / function with -msoft-float. It prevents gcc from using
71	fprs / vrs. */
53c5c3d5 SL	72	#define __libc_tbegin(tdb) __libc_tbegin_base(tdb,,,)
	73
	74	#define __libc_tbegin_retry_output_regs , [R_TX_CNT] "+&d" (__tx_cnt)
	75	#define __libc_tbegin_retry_input_regs(retry_cnt) , [R_RETRY] "d" (retry_cnt)
	76	#define __libc_tbegin_retry_abort_path_insn \
	77	/* If tbegin returned _HTM_TBEGIN_TRANSIENT, retry immediately so \
	78	that max tbegin_cnt transactions are tried. Otherwise return and \
	79	let the caller of this macro do the fallback path. */ \
	80	" jnh 1f\n\t" /* cc 1/3: jump to fallback path. */ \
	81	/* tbegin returned _HTM_TBEGIN_TRANSIENT: retry with transaction. */ \
	82	" crje %[R_TX_CNT], %[R_RETRY], 1f\n\t" /* Reached max retries? */ \
	83	" ahi %[R_TX_CNT], 1\n\t" \
	84	" ppa %[R_TX_CNT], 0, 1\n\t" /* Transaction-Abort Assist. */ \
	85	" j 2b\n\t" /* Loop to tbegin. */
	86
	87	/* Same as __libc_tbegin except if tbegin aborts with _HTM_TBEGIN_TRANSIENT.
	88	Then this macros restores the fpc, fprs and automatically retries up to
	89	retry_cnt tbegins. Further saving of the state is omitted as it is already
	90	saved. This macro calls tbegin at most as retry_cnt + 1 times. */
	91	#define __libc_tbegin_retry(tdb, retry_cnt) \
	92	({ int __ret; \
	93	int __tx_cnt = 0; \
	94	__ret = __libc_tbegin_base(tdb, \
	95	__libc_tbegin_retry_abort_path_insn, \
	96	__libc_tbegin_retry_output_regs, \
	97	__libc_tbegin_retry_input_regs(retry_cnt)); \
	98	__ret; \
	99	})
	100
	101	#define __libc_tbegin_base(tdb, abort_path_insn, output_regs, input_regs) \
8bfc4a2a SL	102	({ int __ret; \
	103	int __fpc; \
	104	char __fprs[TX_FPRS_BYTES]; \
	105	__asm__ __volatile__ (".machine push\n\t" \
	106	".machinemode \"zarch_nohighgprs\"\n\t" \
	107	".machine \"all\"\n\t" \
	108	/* Save state at the outermost transaction. \
	109	As extracting nesting depth is expensive \
	110	on at least zEC12, save fprs at inner \
	111	transactions, too. \
	112	The fpc and fprs are saved here as they \
	113	are not saved by tbegin. There exist no \
	114	call-saved vrs, thus they are not saved \
	115	here. */ \
	116	" efpc %[R_FPC]\n\t" \
	117	TX_SAVE_FPRS \
	118	/* Begin transaction: save all gprs, allow \
	119	ar modification and fp operations. Some \
	120	program-interruptions (e.g. a null \
	121	pointer access) are filtered and the \
	122	trancsaction will abort. In this case \
	123	the normal lock path will execute it \
	124	again and result in a core dump wich does \
	125	now show at tbegin but the real executed \
	126	instruction. */ \
53c5c3d5	127	"2: tbegin 0, 0xFF0E\n\t" \
8bfc4a2a SL	128	/* Branch away in abort case (this is the \
	129	prefered sequence. See PoP in chapter 5 \
	130	Transactional-Execution Facility \
	131	Operation). */ \
	132	" jnz 0f\n\t" \
	133	/* Transaction has successfully started. */ \
	134	" lhi %[R_RET], 0\n\t" \
	135	" j 1f\n\t" \
	136	/* Transaction has aborted. Now we are at \
	137	the outermost transaction. Restore fprs \
	138	and fpc. */ \
	139	"0: ipm %[R_RET]\n\t" \
	140	" srl %[R_RET], 28\n\t" \
	141	" sfpc %[R_FPC]\n\t" \
	142	TX_RESTORE_FPRS \
53c5c3d5	143	abort_path_insn \
8bfc4a2a SL	144	"1:\n\t" \
	145	".machine pop\n" \
	146	: [R_RET] "=&d" (__ret), \
	147	[R_FPC] "=&d" (__fpc) \
53c5c3d5	148	output_regs \
8bfc4a2a	149	: [R_FPRS] "a" (__fprs) \
53c5c3d5	150	input_regs \
8bfc4a2a SL	151	: "cc", "memory"); \
	152	__ret; \
	153	})
	154
	155	/* These builtins are correct. Use them. */
	156	#define __libc_tend() \
	157	({ __asm__ __volatile__ (".machine push\n\t" \
	158	".machinemode \"zarch_nohighgprs\"\n\t" \
	159	".machine \"all\"\n\t"); \
	160	int __ret = __builtin_tend (); \
	161	__asm__ __volatile__ (".machine pop"); \
	162	__ret; \
	163	})
	164
	165	#define __libc_tabort(abortcode) \
	166	__asm__ __volatile__ (".machine push\n\t" \
	167	".machinemode \"zarch_nohighgprs\"\n\t" \
	168	".machine \"all\"\n\t"); \
	169	__builtin_tabort (abortcode); \
	170	__asm__ __volatile__ (".machine pop")
	171
	172	#define __libc_tx_nesting_depth() \
	173	({ __asm__ __volatile__ (".machine push\n\t" \
	174	".machinemode \"zarch_nohighgprs\"\n\t" \
	175	".machine \"all\"\n\t"); \
	176	int __ret = __builtin_tx_nesting_depth (); \
	177	__asm__ __volatile__ (".machine pop"); \
	178	__ret; \
	179	})
	180
	181	#endif