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From: Arnd Bergmann <arnd@arndb.de>
To: linux-arch@vger.kernel.org
Cc: Arnd Bergmann <arnd@arndb.de>,
	kernel-build-reports@lists.linaro.org,
	linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org,
	Russell King <rmk+kernel@armlinux.org.uk>,
	Andrew Morton <akpm@linux-foundation.org>,
	kvmarm@lists.cs.columbia.edu, linux-arm-kernel@vger.kernel.org
Subject: [PATCH 13/13] ARM: avoid 'Q' asm constraint for gcc-4.1 and earlier
Date: Fri, 16 Dec 2016 11:56:34 +0100	[thread overview]
Message-ID: <20161216105634.235457-14-arnd@arndb.de> (raw)
In-Reply-To: <20161216105634.235457-1-arnd@arndb.de>

Building with ancient gcc versions results in a stream of build errors
like:

arch/arm/include/asm/io.h:100: error: impossible constraint in 'asm'
arch/arm/include/asm/io.h:118: error: impossible constraint in 'asm'

This reverts to an older version of __raw_readl, __raw_writel
and __my_cpu_offset, which seem to be the only functions affected
by this.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 arch/arm/include/asm/io.h     | 8 ++++++++
 arch/arm/include/asm/percpu.h | 5 ++++-
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/arch/arm/include/asm/io.h b/arch/arm/include/asm/io.h
index 6f89a4d9fc85..d0f89c4cb8e2 100644
--- a/arch/arm/include/asm/io.h
+++ b/arch/arm/include/asm/io.h
@@ -97,8 +97,12 @@ static inline void __raw_writeb(u8 val, volatile void __iomem *addr)
 #define __raw_writel __raw_writel
 static inline void __raw_writel(u32 val, volatile void __iomem *addr)
 {
+#if GCC_VERSION < 40200
+	*(volatile u32 __force *)addr = val;
+#else
 	asm volatile("str %1, %0"
 		     : : "Qo" (*(volatile u32 __force *)addr), "r" (val));
+#endif
 }
 
 #define __raw_readb __raw_readb
@@ -115,9 +119,13 @@ static inline u8 __raw_readb(const volatile void __iomem *addr)
 static inline u32 __raw_readl(const volatile void __iomem *addr)
 {
 	u32 val;
+#if GCC_VERSION < 40200
+	val = *(volatile u32 __force *)addr;
+#else
 	asm volatile("ldr %0, %1"
 		     : "=r" (val)
 		     : "Qo" (*(volatile u32 __force *)addr));
+#endif
 	return val;
 }
 
diff --git a/arch/arm/include/asm/percpu.h b/arch/arm/include/asm/percpu.h
index a89b4076cde4..dee4c89b4458 100644
--- a/arch/arm/include/asm/percpu.h
+++ b/arch/arm/include/asm/percpu.h
@@ -36,9 +36,12 @@ static inline unsigned long __my_cpu_offset(void)
 	 * We want to allow caching the value, so avoid using volatile and
 	 * instead use a fake stack read to hazard against barrier().
 	 */
+#if GCC_VERSION < 40200
+	asm("mrc p15, 0, %0, c13, c0, 4" : "=r" (off) : : "memory");
+#else
 	asm("mrc p15, 0, %0, c13, c0, 4" : "=r" (off)
 		: "Q" (*(const unsigned long *)current_stack_pointer));
-
+#endif
 	return off;
 }
 #define __my_cpu_offset __my_cpu_offset()
-- 
2.9.0

WARNING: multiple messages have this Message-ID (diff)
From: Arnd Bergmann <arnd@arndb.de>
To: linux-arch@vger.kernel.org
Cc: linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-arm-kernel@vger.kernel.org,
	Russell King <rmk+kernel@armlinux.org.uk>,
	Andrew Morton <akpm@linux-foundation.org>,
	kernel-build-reports@lists.linaro.org,
	kvmarm@lists.cs.columbia.edu, Arnd Bergmann <arnd@arndb.de>
Subject: [PATCH 13/13] ARM: avoid 'Q' asm constraint for gcc-4.1 and earlier
Date: Fri, 16 Dec 2016 11:56:34 +0100	[thread overview]
Message-ID: <20161216105634.235457-14-arnd@arndb.de> (raw)
Message-ID: <20161216105634.wDQcPRNJ8VVApmlZqkZJfr1Kyhnn_DHWVSHdMz-b5Nw@z> (raw)
In-Reply-To: <20161216105634.235457-1-arnd@arndb.de>

Building with ancient gcc versions results in a stream of build errors
like:

arch/arm/include/asm/io.h:100: error: impossible constraint in 'asm'
arch/arm/include/asm/io.h:118: error: impossible constraint in 'asm'

This reverts to an older version of __raw_readl, __raw_writel
and __my_cpu_offset, which seem to be the only functions affected
by this.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 arch/arm/include/asm/io.h     | 8 ++++++++
 arch/arm/include/asm/percpu.h | 5 ++++-
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/arch/arm/include/asm/io.h b/arch/arm/include/asm/io.h
index 6f89a4d9fc85..d0f89c4cb8e2 100644
--- a/arch/arm/include/asm/io.h
+++ b/arch/arm/include/asm/io.h
@@ -97,8 +97,12 @@ static inline void __raw_writeb(u8 val, volatile void __iomem *addr)
 #define __raw_writel __raw_writel
 static inline void __raw_writel(u32 val, volatile void __iomem *addr)
 {
+#if GCC_VERSION < 40200
+	*(volatile u32 __force *)addr = val;
+#else
 	asm volatile("str %1, %0"
 		     : : "Qo" (*(volatile u32 __force *)addr), "r" (val));
+#endif
 }
 
 #define __raw_readb __raw_readb
@@ -115,9 +119,13 @@ static inline u8 __raw_readb(const volatile void __iomem *addr)
 static inline u32 __raw_readl(const volatile void __iomem *addr)
 {
 	u32 val;
+#if GCC_VERSION < 40200
+	val = *(volatile u32 __force *)addr;
+#else
 	asm volatile("ldr %0, %1"
 		     : "=r" (val)
 		     : "Qo" (*(volatile u32 __force *)addr));
+#endif
 	return val;
 }
 
diff --git a/arch/arm/include/asm/percpu.h b/arch/arm/include/asm/percpu.h
index a89b4076cde4..dee4c89b4458 100644
--- a/arch/arm/include/asm/percpu.h
+++ b/arch/arm/include/asm/percpu.h
@@ -36,9 +36,12 @@ static inline unsigned long __my_cpu_offset(void)
 	 * We want to allow caching the value, so avoid using volatile and
 	 * instead use a fake stack read to hazard against barrier().
 	 */
+#if GCC_VERSION < 40200
+	asm("mrc p15, 0, %0, c13, c0, 4" : "=r" (off) : : "memory");
+#else
 	asm("mrc p15, 0, %0, c13, c0, 4" : "=r" (off)
 		: "Q" (*(const unsigned long *)current_stack_pointer));
-
+#endif
 	return off;
 }
 #define __my_cpu_offset __my_cpu_offset()
-- 
2.9.0


  parent reply	other threads:[~2016-12-16 10:56 UTC|newest]

Thread overview: 84+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-12-16 10:56 [RFC] minimum gcc version for kernel: raise to gcc-4.3 or 4.6? Arnd Bergmann
2016-12-16 10:56 ` Arnd Bergmann
2016-12-16 10:56 ` [PATCH 01/13] [HACK] gcc-4.5: avoid link errors for unused function pointers Arnd Bergmann
2016-12-16 10:56   ` Arnd Bergmann
2016-12-16 10:56 ` [PATCH 02/13] KVM: arm: fix gcc-4.5 build Arnd Bergmann
2016-12-16 10:56   ` Arnd Bergmann
2017-01-04 10:38   ` Christoffer Dall
2017-01-04 10:38     ` Christoffer Dall
2016-12-16 10:56 ` [PATCH 03/13] ARM: div64: fix building with gcc-4.5 and lower Arnd Bergmann
2016-12-16 10:56   ` Arnd Bergmann
2016-12-16 10:56 ` [PATCH 04/13] vfio-pci: use 32-bit comparisons for register address for gcc-4.5 Arnd Bergmann
2016-12-16 10:56   ` Arnd Bergmann
2016-12-16 15:30   ` Alex Williamson
2016-12-16 19:50     ` Arnd Bergmann
2016-12-16 10:56 ` [PATCH 05/13] clk: pxa: fix gcc-4.4 build Arnd Bergmann
2016-12-16 10:56   ` Arnd Bergmann
2016-12-16 10:56 ` [PATCH 06/13] ARM: atomic: " Arnd Bergmann
2016-12-16 10:56   ` Arnd Bergmann
2016-12-16 10:56 ` [PATCH 07/13] watchdog: kempld: fix gcc-4.3 build Arnd Bergmann
2016-12-16 10:56   ` Arnd Bergmann
2016-12-16 10:56 ` [PATCH 08/13] arm/arm64: xen: avoid gcc-4.4 warning Arnd Bergmann
2016-12-16 10:56   ` Arnd Bergmann
2016-12-16 10:56 ` [PATCH 09/13] ARM: mark cmpxchg and xchg __always_inline for gcc-4.3 Arnd Bergmann
2016-12-16 10:56   ` Arnd Bergmann
2016-12-16 10:56 ` [PATCH 10/13] asm-generic: mark cmpxchg as " Arnd Bergmann
2016-12-16 10:56   ` Arnd Bergmann
2016-12-16 10:56 ` [PATCH 11/13] fs: fix unsigned enum warning with gcc-4.2 Arnd Bergmann
2016-12-16 10:56   ` Arnd Bergmann
2017-01-03 22:47   ` Brendan Gregg
2017-02-28 21:53     ` Brendan Gregg
2016-12-16 10:56 ` [PATCH 12/13] KVM: arm: avoid binary number literals for gcc-4.2 Arnd Bergmann
2016-12-16 10:56   ` Arnd Bergmann
2017-01-04 10:39   ` Christoffer Dall
2017-01-04 10:39     ` Christoffer Dall
2016-12-16 10:56 ` Arnd Bergmann [this message]
2016-12-16 10:56   ` [PATCH 13/13] ARM: avoid 'Q' asm constraint for gcc-4.1 and earlier Arnd Bergmann
2016-12-16 11:14 ` [RFC] minimum gcc version for kernel: raise to gcc-4.3 or 4.6? Arnd Bergmann
2016-12-16 11:14   ` Arnd Bergmann
2017-04-16 19:52   ` Kees Cook
2017-04-20 10:15     ` Arnd Bergmann
2017-04-20 19:52       ` Kees Cook
2017-04-20 19:52         ` Kees Cook
2017-04-21 20:55         ` Arnd Bergmann
2017-04-21 20:55           ` Arnd Bergmann
2017-04-21 21:05           ` Kees Cook
2017-04-21 21:05             ` Kees Cook
2017-04-22  3:10             ` Maciej W. Rozycki
2017-04-22  3:10               ` Maciej W. Rozycki
2017-04-22 15:30               ` Arnd Bergmann
2017-04-22 15:30                 ` Arnd Bergmann
2017-04-23 20:13                 ` Geert Uytterhoeven
2017-04-23 20:13                   ` Geert Uytterhoeven
2017-04-24  9:44                   ` Arnd Bergmann
2017-04-24  9:44                     ` Arnd Bergmann
2017-04-24 10:17                     ` Geert Uytterhoeven
2017-04-24 10:17                       ` Geert Uytterhoeven
2017-04-24 14:13                       ` Arnd Bergmann
2017-04-24 16:53                     ` Maciej W. Rozycki
2017-04-24 17:29                       ` Arnd Bergmann
2017-04-24 18:16                         ` Geert Uytterhoeven
2017-04-24 18:16                           ` Geert Uytterhoeven
2017-04-24 18:30                         ` Maciej W. Rozycki
2017-04-24 18:30                           ` Maciej W. Rozycki
2017-04-24 20:30                           ` Arnd Bergmann
2017-04-24 20:52                             ` Kees Cook
2017-04-25  7:06                               ` Geert Uytterhoeven
2017-04-25  7:06                                 ` Geert Uytterhoeven
2017-04-25  9:22     ` Suzuki K Poulose
2017-04-25  9:22       ` Suzuki K Poulose
2016-12-16 15:54 ` Geert Uytterhoeven
2016-12-16 15:54   ` Geert Uytterhoeven
2016-12-16 19:58   ` Arnd Bergmann
2016-12-16 19:58     ` Arnd Bergmann
2016-12-16 20:34     ` Geert Uytterhoeven
2016-12-16 20:34       ` Geert Uytterhoeven
2016-12-16 17:00 ` Sebastian Andrzej Siewior
2016-12-16 22:00   ` Arnd Bergmann
2016-12-16 22:00     ` Arnd Bergmann
2016-12-17 11:29     ` Sebastian Andrzej Siewior
2016-12-17 11:29       ` Sebastian Andrzej Siewior
2017-01-02 12:23       ` Russell King - ARM Linux
2017-01-02 12:23         ` Russell King - ARM Linux
2016-12-20  9:59     ` Heiko Carstens
2016-12-20  9:59       ` Heiko Carstens

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