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From: Miguel Bernal Marin <miguel.bernal.marin@linux.intel.com>
To: Josh Poimboeuf <jpoimboe@redhat.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Ingo Molnar <mingo@redhat.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	"H . Peter Anvin" <hpa@zytor.com>
Cc: linux-kernel@vger.kernel.org, x86@kernel.org
Subject: [PATCH v3 6/6] x86, asm/rwsem: Use named operands in __downgrade_write()
Date: Tue, 19 Sep 2017 18:37:45 -0500	[thread overview]
Message-ID: <20170919233745.15343-7-miguel.bernal.marin@linux.intel.com> (raw)
In-Reply-To: <20170919233745.15343-1-miguel.bernal.marin@linux.intel.com>

Since GCC version 3.1, it is possible to specify input and output
operands using symbolic names which can be referenced within the
assembler code.

Convert to named operands makes easy to understand and maintain for
future changes.

Signed-off-by: Miguel Bernal Marin <miguel.bernal.marin@linux.intel.com>
---
 arch/x86/include/asm/rwsem.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/include/asm/rwsem.h b/arch/x86/include/asm/rwsem.h
index 3245902e961f..1f5d083599ba 100644
--- a/arch/x86/include/asm/rwsem.h
+++ b/arch/x86/include/asm/rwsem.h
@@ -208,7 +208,7 @@ static inline void __downgrade_write(struct rw_semaphore *sem)
 	register void *__sp asm(_ASM_SP);
 
 	asm volatile("# beginning __downgrade_write\n\t"
-		     LOCK_PREFIX _ASM_ADD "%3,(%2)\n\t"
+		     LOCK_PREFIX _ASM_ADD "%[inc],(%[sem])\n\t"
 		     /*
 		      * transitions 0xZZZZ0001 -> 0xYYYY0001 (i386)
 		      *     0xZZZZZZZZ00000001 -> 0xYYYYYYYY00000001 (x86_64)
@@ -218,7 +218,7 @@ static inline void __downgrade_write(struct rw_semaphore *sem)
 		     "1:\n\t"
 		     "# ending __downgrade_write\n"
 		     : "+m" (sem->count), "+r" (__sp)
-		     : "a" (sem), "er" (-RWSEM_WAITING_BIAS)
+		     : [sem] "a" (sem), [inc] "er" (-RWSEM_WAITING_BIAS)
 		     : "memory", "cc");
 }
 
-- 
2.14.1

  parent reply	other threads:[~2017-09-19 23:38 UTC|newest]

Thread overview: 27+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-09-06  5:26 [PATCH 0/3] locking/rwsem/x86: Add stack frame dependency for some inline asm Miguel Bernal Marin
2017-09-06  5:26 ` [PATCH 1/3] locking/rwsem/x86: Add stack frame dependency for __up_read() Miguel Bernal Marin
2017-09-06  5:26 ` [PATCH 2/3] locking/rwsem/x86: Add stack frame dependency for __up_write() Miguel Bernal Marin
2017-09-06  5:26 ` [PATCH 3/3] locking/rwsem/x86: Add stack frame dependency for __downgrade_write() Miguel Bernal Marin
2017-09-06 21:33   ` Josh Poimboeuf
2017-09-06 22:14     ` Miguel Bernal Marin
2017-09-07  7:04     ` Peter Zijlstra
2017-09-06 22:44 ` [PATCH v2 0/3] locking/rwsem/x86: Add stack frame dependency for some inline asm Miguel Bernal Marin
2017-09-06 22:44   ` [PATCH v2 1/3] locking/rwsem/x86: Add stack frame dependency for __up_read() Miguel Bernal Marin
2017-09-07  7:12     ` Ingo Molnar
2017-09-14 21:42       ` Miguel Bernal Marin
2017-09-06 22:45   ` [PATCH v2 2/3] locking/rwsem/x86: Add stack frame dependency for __up_write() Miguel Bernal Marin
2017-09-06 22:45   ` [PATCH v2 3/3] locking/rwsem/x86: Add stack frame dependency for __downgrade_write() Miguel Bernal Marin
2017-09-06 23:05   ` [PATCH v2 0/3] locking/rwsem/x86: Add stack frame dependency for some inline asm Josh Poimboeuf
2017-09-19 23:37 ` [PATCH v3 0/6] " Miguel Bernal Marin
2017-09-19 23:37   ` [PATCH v3 1/6] locking/rwsem/x86: Add stack frame dependency for __up_read() Miguel Bernal Marin
2017-09-19 23:37   ` [PATCH v3 2/6] locking/rwsem/x86: Add stack frame dependency for __up_write() Miguel Bernal Marin
2017-09-19 23:37   ` [PATCH v3 3/6] locking/rwsem/x86: Add stack frame dependency for __downgrade_write() Miguel Bernal Marin
2017-09-19 23:37   ` [PATCH v3 4/6] x86, asm/rwsem: Use named operands in __up_read() Miguel Bernal Marin
2017-09-19 23:37   ` [PATCH v3 5/6] x86, asm/rwsem: Use named operands in __up_write() Miguel Bernal Marin
2017-09-19 23:37   ` Miguel Bernal Marin [this message]
2017-09-20 21:24   ` [PATCH v3 0/6] locking/rwsem/x86: Add stack frame dependency for some inline asm Josh Poimboeuf
2017-09-21 16:59     ` Miguel Bernal Marin
2017-09-25 17:34     ` Miguel Bernal Marin
2017-09-25 19:00       ` Josh Poimboeuf
2017-09-25 19:03         ` Josh Poimboeuf
2017-09-25 21:34           ` Miguel Bernal Marin

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