From: Robert Jarzmik <robert.jarzmik@free.fr>
To: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: linux-arm-kernel@lists.infradead.org,
davinci-linux-open-source@linux.davincidsp.com,
linux-samsung-soc@vger.kernel.org, kvm@vger.kernel.org,
linux-sh@vger.kernel.org, linux-crypto@vger.kernel.org,
linux-tegra@vger.kernel.org, xen-devel@lists.xenproject.org,
linux-omap@vger.kernel.org, kvmarm@lists.cs.columbia.edu
Subject: Re: [PATCH] ARM: convert all "mov.* pc, reg" to "bx reg" for ARMv6+ (part1)
Date: Wed, 02 Jul 2014 00:42:06 +0200 [thread overview]
Message-ID: <87y4wcog5d.fsf@free.fr> (raw)
In-Reply-To: <E1X20mL-00083I-Sv@rmk-PC.arm.linux.org.uk> (Russell King's message of "Tue, 01 Jul 2014 17:19:33 +0100")
Russell King <rmk+kernel@arm.linux.org.uk> writes:
> ARMv6 and greater introduced a new instruction ("bx") which can be used
> to return from function calls. Recent CPUs perform better when the
> "bx lr" instruction is used rather than the "mov pc, lr" instruction,
> and this sequence is strongly recommended to be used by the ARM
> architecture manual (section A.4.1.1).
For ARMv5 - XScale, and more specificaly the mioa701_bootresume.S path (suspend
to RAM) :
Tested-by: Robert Jarzmik <robert.jarzmik@free.fr>
Cheers.
--
Robert
WARNING: multiple messages have this Message-ID (diff)
From: Robert Jarzmik <robert.jarzmik@free.fr>
To: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: linux-arm-kernel@lists.infradead.org,
davinci-linux-open-source@linux.davincidsp.com,
linux-samsung-soc@vger.kernel.org, kvm@vger.kernel.org,
linux-sh@vger.kernel.org, linux-crypto@vger.kernel.org,
linux-tegra@vger.kernel.org, xen-devel@lists.xenproject.org,
linux-omap@vger.kernel.org, kvmarm@lists.cs.columbia.edu
Subject: Re: [PATCH] ARM: convert all "mov.* pc, reg" to "bx reg" for ARMv6+ (part1)
Date: Tue, 01 Jul 2014 22:42:06 +0000 [thread overview]
Message-ID: <87y4wcog5d.fsf@free.fr> (raw)
In-Reply-To: <E1X20mL-00083I-Sv@rmk-PC.arm.linux.org.uk> (Russell King's message of "Tue, 01 Jul 2014 17:19:33 +0100")
Russell King <rmk+kernel@arm.linux.org.uk> writes:
> ARMv6 and greater introduced a new instruction ("bx") which can be used
> to return from function calls. Recent CPUs perform better when the
> "bx lr" instruction is used rather than the "mov pc, lr" instruction,
> and this sequence is strongly recommended to be used by the ARM
> architecture manual (section A.4.1.1).
For ARMv5 - XScale, and more specificaly the mioa701_bootresume.S path (suspend
to RAM) :
Tested-by: Robert Jarzmik <robert.jarzmik@free.fr>
Cheers.
--
Robert
WARNING: multiple messages have this Message-ID (diff)
From: robert.jarzmik@free.fr (Robert Jarzmik)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] ARM: convert all "mov.* pc, reg" to "bx reg" for ARMv6+ (part1)
Date: Wed, 02 Jul 2014 00:42:06 +0200 [thread overview]
Message-ID: <87y4wcog5d.fsf@free.fr> (raw)
In-Reply-To: <E1X20mL-00083I-Sv@rmk-PC.arm.linux.org.uk> (Russell King's message of "Tue, 01 Jul 2014 17:19:33 +0100")
Russell King <rmk+kernel@arm.linux.org.uk> writes:
> ARMv6 and greater introduced a new instruction ("bx") which can be used
> to return from function calls. Recent CPUs perform better when the
> "bx lr" instruction is used rather than the "mov pc, lr" instruction,
> and this sequence is strongly recommended to be used by the ARM
> architecture manual (section A.4.1.1).
For ARMv5 - XScale, and more specificaly the mioa701_bootresume.S path (suspend
to RAM) :
Tested-by: Robert Jarzmik <robert.jarzmik@free.fr>
Cheers.
--
Robert
next prev parent reply other threads:[~2014-07-01 22:42 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-07-01 16:19 [PATCH] ARM: convert all "mov.* pc, reg" to "bx reg" for ARMv6+ (part1) Russell King
2014-07-01 16:19 ` Russell King
2014-07-01 16:19 ` Russell King
2014-07-01 16:42 ` Måns Rullgård
2014-07-01 19:26 ` Stephen Warren
[not found] ` <E1X20mL-00083I-Sv-eh5Bv4kxaXIANfyc6IWni62ZND6+EDdj@public.gmane.org>
2014-07-01 16:42 ` Måns Rullgård
2014-07-01 16:42 ` Måns Rullgård
2014-07-01 16:42 ` Måns Rullgård
2014-07-01 16:42 ` Måns Rullgård
2014-07-01 17:13 ` Russell King - ARM Linux
2014-07-01 17:13 ` Russell King - ARM Linux
2014-07-01 17:13 ` Russell King - ARM Linux
2014-07-01 17:13 ` Russell King - ARM Linux
2014-07-01 17:24 ` Måns Rullgård
2014-07-01 17:24 ` Måns Rullgård
2014-07-01 17:24 ` Måns Rullgård
2014-07-01 17:35 ` Will Deacon
2014-07-01 17:35 ` Will Deacon
2014-07-01 17:35 ` Will Deacon
2014-07-01 17:35 ` Will Deacon
2014-07-01 20:04 ` Måns Rullgård
2014-07-01 20:04 ` Måns Rullgård
2014-07-01 20:04 ` Måns Rullgård
2014-07-01 20:04 ` Måns Rullgård
2014-07-01 20:04 ` Måns Rullgård
2014-07-02 3:17 ` Nicolas Pitre
2014-07-02 3:17 ` Nicolas Pitre
2014-07-02 3:17 ` Nicolas Pitre
2014-07-02 3:17 ` Nicolas Pitre
2014-07-01 17:24 ` Måns Rullgård
2014-07-01 19:26 ` Stephen Warren
2014-07-01 19:26 ` Stephen Warren
2014-07-01 19:26 ` Stephen Warren
2014-07-01 22:42 ` Robert Jarzmik [this message]
2014-07-01 22:42 ` Robert Jarzmik
2014-07-01 22:42 ` Robert Jarzmik
2014-07-01 22:42 ` Robert Jarzmik
2014-07-05 1:06 ` Tomasz Figa
2014-07-05 1:06 ` Tomasz Figa
2014-07-05 1:06 ` Tomasz Figa
2014-07-05 1:06 ` Tomasz Figa
-- strict thread matches above, loose matches on Subject: below --
2014-07-01 16:19 [PATCH] ARM: convert all "mov.* pc, reg" to "bx reg" for ARMv6+ (part2) Russell King
2014-07-01 16:19 ` Russell King
2014-07-01 16:19 ` Russell King
2014-07-01 16:19 [PATCH] ARM: convert all "mov.* pc, reg" to "bx reg" for ARMv6+ (part1) Russell King
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