From: Will Deacon <will.deacon@arm.com>
To: linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: arnd@arndb.de, monstr@monstr.eu, dhowells@redhat.com,
broonie@linaro.org, benh@kernel.crashing.org,
peterz@infradead.org, paulmck@linux.vnet.ibm.com,
Will Deacon <will.deacon@arm.com>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>
Subject: [PATCH v2 16/18] x86: io: implement dummy relaxed accessor macros for writes
Date: Thu, 22 May 2014 17:47:28 +0100 [thread overview]
Message-ID: <1400777250-17335-17-git-send-email-will.deacon@arm.com> (raw)
In-Reply-To: <1400777250-17335-1-git-send-email-will.deacon@arm.com>
write{b,w,l,q}_relaxed are implemented by some architectures in order to
permit memory-mapped I/O accesses with weaker barrier semantics than the
non-relaxed variants.
This patch adds dummy macros for the read and write accessors to x86,
which simply expand to the non-relaxed variants. Note that this
strengthens the relaxed read accessors, since they are now ordered with
respect to each other by way of a compiler barrier.
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
---
arch/x86/include/asm/io.h | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/arch/x86/include/asm/io.h b/arch/x86/include/asm/io.h
index b8237d8a1e0c..56d6d43aca9b 100644
--- a/arch/x86/include/asm/io.h
+++ b/arch/x86/include/asm/io.h
@@ -67,13 +67,16 @@ build_mmio_write(__writeb, "b", unsigned char, "q", )
build_mmio_write(__writew, "w", unsigned short, "r", )
build_mmio_write(__writel, "l", unsigned int, "r", )
-#define readb_relaxed(a) __readb(a)
-#define readw_relaxed(a) __readw(a)
-#define readl_relaxed(a) __readl(a)
+#define readb_relaxed(a) readb(a)
+#define readw_relaxed(a) readw(a)
+#define readl_relaxed(a) readl(a)
#define __raw_readb __readb
#define __raw_readw __readw
#define __raw_readl __readl
+#define writeb_relaxed(v, a) writeb(v, a)
+#define writew_relaxed(v, a) writew(v, a)
+#define writel_relaxed(v, a) writel(v, a)
#define __raw_writeb __writeb
#define __raw_writew __writew
#define __raw_writel __writel
@@ -86,6 +89,7 @@ build_mmio_read(readq, "q", unsigned long, "=r", :"memory")
build_mmio_write(writeq, "q", unsigned long, "r", :"memory")
#define readq_relaxed(a) readq(a)
+#define writeq_relaxed(v, a) writeq(v, a)
#define __raw_readq(a) readq(a)
#define __raw_writeq(val, addr) writeq(val, addr)
--
1.9.2
next prev parent reply other threads:[~2014-05-22 16:49 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-05-22 16:47 [PATCH v2 00/18] Cross-architecture definitions of relaxed MMIO accessors Will Deacon
2014-05-22 16:47 ` [PATCH v2 01/18] asm-generic: io: implement relaxed accessor macros as conditional wrappers Will Deacon
2014-05-22 16:47 ` [PATCH v2 02/18] microblaze: io: remove dummy relaxed accessor macros Will Deacon
2014-05-22 16:47 ` [PATCH v2 03/18] s390: io: remove dummy relaxed accessor macros for reads Will Deacon
2014-05-22 16:47 ` [PATCH v2 04/18] xtensa: " Will Deacon
2014-05-22 16:47 ` [PATCH v2 05/18] alpha: io: implement relaxed accessor macros for writes Will Deacon
2014-05-22 18:15 ` Richard Henderson
2014-05-22 16:47 ` [PATCH v2 06/18] frv: io: implement dummy " Will Deacon
2014-05-22 16:47 ` [PATCH v2 07/18] cris: " Will Deacon
2014-05-22 16:47 ` [PATCH v2 08/18] ia64: " Will Deacon
2014-05-22 16:47 ` [PATCH v2 09/18] m32r: " Will Deacon
2014-05-22 16:47 ` [PATCH v2 10/18] m68k: " Will Deacon
2014-05-22 16:47 ` [PATCH v2 11/18] mn10300: " Will Deacon
2014-05-22 16:47 ` [PATCH v2 12/18] parisc: " Will Deacon
2014-05-22 16:47 ` [PATCH v2 13/18] powerpc: " Will Deacon
2014-05-22 16:47 ` [PATCH v2 14/18] sparc: " Will Deacon
2014-05-22 18:18 ` Sam Ravnborg
2014-05-23 14:38 ` Will Deacon
2014-05-30 0:10 ` David Miller
2014-05-22 16:47 ` [PATCH v2 15/18] tile: " Will Deacon
2014-05-22 16:47 ` Will Deacon [this message]
2014-05-22 17:15 ` [PATCH v2 16/18] x86: " H. Peter Anvin
2014-05-23 14:46 ` Will Deacon
2014-05-23 14:53 ` H. Peter Anvin
2014-05-23 14:57 ` Will Deacon
2014-05-23 15:20 ` H. Peter Anvin
2014-05-23 15:34 ` Will Deacon
2014-05-23 15:43 ` H. Peter Anvin
2014-05-23 15:56 ` Peter Zijlstra
2014-05-23 16:12 ` H. Peter Anvin
2014-05-23 16:21 ` Peter Zijlstra
2014-05-23 16:31 ` Geert Uytterhoeven
2014-05-23 16:35 ` H. Peter Anvin
2014-05-22 16:47 ` [PATCH v2 17/18] documentation: memory-barriers: clarify relaxed io accessor semantics Will Deacon
2014-05-22 16:47 ` [PATCH v2 18/18] asm-generic: io: define relaxed accessor macros unconditionally Will Deacon
2014-05-25 21:46 ` [PATCH v2 00/18] Cross-architecture definitions of relaxed MMIO accessors Benjamin Herrenschmidt
2014-05-27 19:32 ` Will Deacon
2014-05-27 20:21 ` Benjamin Herrenschmidt
2014-05-27 20:32 ` Will Deacon
2014-05-25 21:47 ` Benjamin Herrenschmidt
2014-05-27 19:34 ` Will Deacon
2014-05-27 20:23 ` Benjamin Herrenschmidt
2014-05-27 20:34 ` Will Deacon
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