<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/arch/arm, branch v3.2.70</title>
<subtitle>Linux kernel for Apalis and Colibri modules</subtitle>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/'/>
<entry>
<title>ARM: 8320/1: fix integer overflow in ELF_ET_DYN_BASE</title>
<updated>2015-08-06T23:32:02+00:00</updated>
<author>
<name>Andrey Ryabinin</name>
<email>a.ryabinin@samsung.com</email>
</author>
<published>2015-03-20T14:42:27+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=0e75ad3733bf2086beb13b493c73f168a691e6e4'/>
<id>0e75ad3733bf2086beb13b493c73f168a691e6e4</id>
<content type='text'>
commit 8defb3367fcd19d1af64c07792aade0747b54e0f upstream.

Usually ELF_ET_DYN_BASE is 2/3 of TASK_SIZE. With 3G/1G user/kernel
split this is not so, because 2*TASK_SIZE overflows 32 bits,
so the actual value of ELF_ET_DYN_BASE is:
	(2 * TASK_SIZE / 3) = 0x2a000000

When ASLR is disabled PIE binaries will load at ELF_ET_DYN_BASE address.
On 32bit platforms AddressSanitzer uses addresses [0x20000000 - 0x40000000]
for shadow memory [1]. So ASan doesn't work for PIE binaries when ASLR disabled
as it fails to map shadow memory.
Also after Kees's 'split ET_DYN ASLR from mmap ASLR' patchset PIE binaries
has a high chance of loading somewhere in between [0x2a000000 - 0x40000000]
even if ASLR enabled. This makes ASan with PIE absolutely incompatible.

Fix overflow by dividing TASK_SIZE prior to multiplying.
After this patch ELF_ET_DYN_BASE equals to (for CONFIG_VMSPLIT_3G=y):
	(TASK_SIZE / 3 * 2) = 0x7f555554

[1] https://code.google.com/p/address-sanitizer/wiki/AddressSanitizerAlgorithm#Mapping

Signed-off-by: Andrey Ryabinin &lt;a.ryabinin@samsung.com&gt;
Reported-by: Maria Guseva &lt;m.guseva@samsung.com&gt;
Signed-off-by: Russell King &lt;rmk+kernel@arm.linux.org.uk&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 8defb3367fcd19d1af64c07792aade0747b54e0f upstream.

Usually ELF_ET_DYN_BASE is 2/3 of TASK_SIZE. With 3G/1G user/kernel
split this is not so, because 2*TASK_SIZE overflows 32 bits,
so the actual value of ELF_ET_DYN_BASE is:
	(2 * TASK_SIZE / 3) = 0x2a000000

When ASLR is disabled PIE binaries will load at ELF_ET_DYN_BASE address.
On 32bit platforms AddressSanitzer uses addresses [0x20000000 - 0x40000000]
for shadow memory [1]. So ASan doesn't work for PIE binaries when ASLR disabled
as it fails to map shadow memory.
Also after Kees's 'split ET_DYN ASLR from mmap ASLR' patchset PIE binaries
has a high chance of loading somewhere in between [0x2a000000 - 0x40000000]
even if ASLR enabled. This makes ASan with PIE absolutely incompatible.

Fix overflow by dividing TASK_SIZE prior to multiplying.
After this patch ELF_ET_DYN_BASE equals to (for CONFIG_VMSPLIT_3G=y):
	(TASK_SIZE / 3 * 2) = 0x7f555554

[1] https://code.google.com/p/address-sanitizer/wiki/AddressSanitizerAlgorithm#Mapping

Signed-off-by: Andrey Ryabinin &lt;a.ryabinin@samsung.com&gt;
Reported-by: Maria Guseva &lt;m.guseva@samsung.com&gt;
Signed-off-by: Russell King &lt;rmk+kernel@arm.linux.org.uk&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ARM: 8284/1: sa1100: clear RCSR_SMR on resume</title>
<updated>2015-05-09T22:16:13+00:00</updated>
<author>
<name>Dmitry Eremin-Solenikov</name>
<email>dbaryshkov@gmail.com</email>
</author>
<published>2015-01-15T02:06:22+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=268b9d240c0cbcbc25f3a5a54041f001cd91f3d4'/>
<id>268b9d240c0cbcbc25f3a5a54041f001cd91f3d4</id>
<content type='text'>
commit e461894dc2ce7778ccde1c3483c9b15a85a7fc5f upstream.

StrongARM core uses RCSR SMR bit to tell to bootloader that it was reset
by entering the sleep mode. After we have resumed, there is little point
in having that bit enabled. Moreover, if this bit is set before reboot,
the bootloader can become confused. Thus clear the SMR bit on resume
just before clearing the scratchpad (resume address) register.

Signed-off-by: Dmitry Eremin-Solenikov &lt;dbaryshkov@gmail.com&gt;
Signed-off-by: Russell King &lt;rmk+kernel@arm.linux.org.uk&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit e461894dc2ce7778ccde1c3483c9b15a85a7fc5f upstream.

StrongARM core uses RCSR SMR bit to tell to bootloader that it was reset
by entering the sleep mode. After we have resumed, there is little point
in having that bit enabled. Moreover, if this bit is set before reboot,
the bootloader can become confused. Thus clear the SMR bit on resume
just before clearing the scratchpad (resume address) register.

Signed-off-by: Dmitry Eremin-Solenikov &lt;dbaryshkov@gmail.com&gt;
Signed-off-by: Russell King &lt;rmk+kernel@arm.linux.org.uk&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>hx4700: regulator: declare full constraints</title>
<updated>2015-05-09T22:16:11+00:00</updated>
<author>
<name>Martin Vajnar</name>
<email>martin.vajnar@gmail.com</email>
</author>
<published>2014-12-23T23:27:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=931c2f0e27864a1def4755d072c856bdbe504a7d'/>
<id>931c2f0e27864a1def4755d072c856bdbe504a7d</id>
<content type='text'>
commit a52d209336f8fc7483a8c7f4a8a7d2a8e1692a6c upstream.

Since the removal of CONFIG_REGULATOR_DUMMY option, the touchscreen stopped
working. This patch enables the "replacement" for REGULATOR_DUMMY and
allows the touchscreen to work even though there is no regulator for "vcc".

Signed-off-by: Martin Vajnar &lt;martin.vajnar@gmail.com&gt;
Signed-off-by: Robert Jarzmik &lt;robert.jarzmik@free.fr&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit a52d209336f8fc7483a8c7f4a8a7d2a8e1692a6c upstream.

Since the removal of CONFIG_REGULATOR_DUMMY option, the touchscreen stopped
working. This patch enables the "replacement" for REGULATOR_DUMMY and
allows the touchscreen to work even though there is no regulator for "vcc".

Signed-off-by: Martin Vajnar &lt;martin.vajnar@gmail.com&gt;
Signed-off-by: Robert Jarzmik &lt;robert.jarzmik@free.fr&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ARM: pxa: add regulator_has_full_constraints to spitz board file</title>
<updated>2015-05-09T22:16:11+00:00</updated>
<author>
<name>Dmitry Eremin-Solenikov</name>
<email>dbaryshkov@gmail.com</email>
</author>
<published>2014-12-04T11:10:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=40001726a970d38ce20af1c91563c37fbf1e6447'/>
<id>40001726a970d38ce20af1c91563c37fbf1e6447</id>
<content type='text'>
commit baad2dc49c5d970ea881d92981a1b76c94a7b7a1 upstream.

Add regulator_has_full_constraints() call to spitz board file to let
regulator core know that we do not have any additional regulators left.
This lets it substitute unprovided regulators with dummy ones.

This fixes the following warnings that can be seen on spitz if
regulators are enabled:

ads7846 spi2.0: unable to get regulator: -517
spi spi2.0: Driver ads7846 requests probe deferral

Signed-off-by: Dmitry Eremin-Solenikov &lt;dbaryshkov@gmail.com&gt;
Acked-by: Mark Brown &lt;broonie@kernel.org&gt;
Signed-off-by: Robert Jarzmik &lt;robert.jarzmik@free.fr&gt;
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit baad2dc49c5d970ea881d92981a1b76c94a7b7a1 upstream.

Add regulator_has_full_constraints() call to spitz board file to let
regulator core know that we do not have any additional regulators left.
This lets it substitute unprovided regulators with dummy ones.

This fixes the following warnings that can be seen on spitz if
regulators are enabled:

ads7846 spi2.0: unable to get regulator: -517
spi spi2.0: Driver ads7846 requests probe deferral

Signed-off-by: Dmitry Eremin-Solenikov &lt;dbaryshkov@gmail.com&gt;
Acked-by: Mark Brown &lt;broonie@kernel.org&gt;
Signed-off-by: Robert Jarzmik &lt;robert.jarzmik@free.fr&gt;
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ARM: pxa: add regulator_has_full_constraints to poodle board file</title>
<updated>2015-05-09T22:16:10+00:00</updated>
<author>
<name>Dmitry Eremin-Solenikov</name>
<email>dbaryshkov@gmail.com</email>
</author>
<published>2014-12-04T11:10:01+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=4ba2987dd7a28584355ce42dc63eb2faa52023a4'/>
<id>4ba2987dd7a28584355ce42dc63eb2faa52023a4</id>
<content type='text'>
commit 9bc78f32c2e430aebf6def965b316aa95e37a20c upstream.

Add regulator_has_full_constraints() call to poodle board file to let
regulator core know that we do not have any additional regulators left.
This lets it substitute unprovided regulators with dummy ones.

This fixes the following warnings that can be seen on poodle if
regulators are enabled:

ads7846 spi1.0: unable to get regulator: -517
spi spi1.0: Driver ads7846 requests probe deferral
wm8731 0-001b: Failed to get supply 'AVDD': -517
wm8731 0-001b: Failed to request supplies: -517
wm8731 0-001b: ASoC: failed to probe component -517

Signed-off-by: Dmitry Eremin-Solenikov &lt;dbaryshkov@gmail.com&gt;
Acked-by: Mark Brown &lt;broonie@kernel.org&gt;
Signed-off-by: Robert Jarzmik &lt;robert.jarzmik@free.fr&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 9bc78f32c2e430aebf6def965b316aa95e37a20c upstream.

Add regulator_has_full_constraints() call to poodle board file to let
regulator core know that we do not have any additional regulators left.
This lets it substitute unprovided regulators with dummy ones.

This fixes the following warnings that can be seen on poodle if
regulators are enabled:

ads7846 spi1.0: unable to get regulator: -517
spi spi1.0: Driver ads7846 requests probe deferral
wm8731 0-001b: Failed to get supply 'AVDD': -517
wm8731 0-001b: Failed to request supplies: -517
wm8731 0-001b: ASoC: failed to probe component -517

Signed-off-by: Dmitry Eremin-Solenikov &lt;dbaryshkov@gmail.com&gt;
Acked-by: Mark Brown &lt;broonie@kernel.org&gt;
Signed-off-by: Robert Jarzmik &lt;robert.jarzmik@free.fr&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ARM: pxa: add regulator_has_full_constraints to corgi board file</title>
<updated>2015-05-09T22:16:10+00:00</updated>
<author>
<name>Dmitry Eremin-Solenikov</name>
<email>dbaryshkov@gmail.com</email>
</author>
<published>2014-12-04T11:10:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=04316cd7c080774664aad00a2e49ac6e501ca617'/>
<id>04316cd7c080774664aad00a2e49ac6e501ca617</id>
<content type='text'>
commit 271e80176aae4e5b481f4bb92df9768c6075bbca upstream.

Add regulator_has_full_constraints() call to corgi board file to let
regulator core know that we do not have any additional regulators left.
This lets it substitute unprovided regulators with dummy ones.

This fixes the following warnings that can be seen on corgi if
regulators are enabled:

ads7846 spi1.0: unable to get regulator: -517
spi spi1.0: Driver ads7846 requests probe deferral
wm8731 0-001b: Failed to get supply 'AVDD': -517
wm8731 0-001b: Failed to request supplies: -517
wm8731 0-001b: ASoC: failed to probe component -517
corgi-audio corgi-audio: ASoC: failed to instantiate card -517

Signed-off-by: Dmitry Eremin-Solenikov &lt;dbaryshkov@gmail.com&gt;
Acked-by: Mark Brown &lt;broonie@kernel.org&gt;
Signed-off-by: Robert Jarzmik &lt;robert.jarzmik@free.fr&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 271e80176aae4e5b481f4bb92df9768c6075bbca upstream.

Add regulator_has_full_constraints() call to corgi board file to let
regulator core know that we do not have any additional regulators left.
This lets it substitute unprovided regulators with dummy ones.

This fixes the following warnings that can be seen on corgi if
regulators are enabled:

ads7846 spi1.0: unable to get regulator: -517
spi spi1.0: Driver ads7846 requests probe deferral
wm8731 0-001b: Failed to get supply 'AVDD': -517
wm8731 0-001b: Failed to request supplies: -517
wm8731 0-001b: ASoC: failed to probe component -517
corgi-audio corgi-audio: ASoC: failed to instantiate card -517

Signed-off-by: Dmitry Eremin-Solenikov &lt;dbaryshkov@gmail.com&gt;
Acked-by: Mark Brown &lt;broonie@kernel.org&gt;
Signed-off-by: Robert Jarzmik &lt;robert.jarzmik@free.fr&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>bus: omap_l3_noc: Correct returning IRQ_HANDLED unconditionally in the irq handler</title>
<updated>2015-02-20T00:49:25+00:00</updated>
<author>
<name>Keerthy</name>
<email>j-keerthy@ti.com</email>
</author>
<published>2014-11-10T18:19:48+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=3cf6ed7571ec1ad4cbec7ae63fef0288c2370c0b'/>
<id>3cf6ed7571ec1ad4cbec7ae63fef0288c2370c0b</id>
<content type='text'>
commit c4cf0935a2d8fe6d186bf4253ea3c4b4a8a8a710 upstream.

Correct returning IRQ_HANDLED unconditionally in the irq handler.
Return IRQ_NONE for some interrupt which we do not expect to be
handled in this handler. This prevents kernel stalling with back
to back spurious interrupts.

Fixes: 2722e56de6 ("OMAP4: l3: Introduce l3-interconnect error handling driver")
Acked-by: Nishanth Menon &lt;nm@ti.com&gt;
Signed-off-by: Keerthy &lt;j-keerthy@ti.com&gt;
Signed-off-by: Tony Lindgren &lt;tony@atomide.com&gt;
[bwh: Backported to 3.2: adjust filename, indentation]
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit c4cf0935a2d8fe6d186bf4253ea3c4b4a8a8a710 upstream.

Correct returning IRQ_HANDLED unconditionally in the irq handler.
Return IRQ_NONE for some interrupt which we do not expect to be
handled in this handler. This prevents kernel stalling with back
to back spurious interrupts.

Fixes: 2722e56de6 ("OMAP4: l3: Introduce l3-interconnect error handling driver")
Acked-by: Nishanth Menon &lt;nm@ti.com&gt;
Signed-off-by: Keerthy &lt;j-keerthy@ti.com&gt;
Signed-off-by: Tony Lindgren &lt;tony@atomide.com&gt;
[bwh: Backported to 3.2: adjust filename, indentation]
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ARM: 8216/1: xscale: correct auxiliary register in suspend/resume</title>
<updated>2014-12-14T16:23:58+00:00</updated>
<author>
<name>Dmitry Eremin-Solenikov</name>
<email>dbaryshkov@gmail.com</email>
</author>
<published>2014-11-21T14:29:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=40f674b67601ebf7772372caea07824e911e5ac8'/>
<id>40f674b67601ebf7772372caea07824e911e5ac8</id>
<content type='text'>
commit ef59a20ba375aeb97b3150a118318884743452a8 upstream.

According to the manuals I have, XScale auxiliary register should be
reached with opc_2 = 1 instead of crn = 1. cpu_xscale_proc_init
correctly uses c1, c0, 1 arguments, but cpu_xscale_do_suspend and
cpu_xscale_do_resume use c1, c1, 0. Correct suspend/resume functions to
also use c1, c0, 1.

The issue was primarily noticed thanks to qemu reporing "unsupported
instruction" on the pxa suspend path. Confirmed in PXA210/250 and PXA255
XScale Core manuals and in PXA270 and PXA320 Developers Guides.

Harware tested by me on tosa (pxa255). Robert confirmed on pxa270 board.

Tested-by: Robert Jarzmik &lt;robert.jarzmik@free.fr&gt;
Signed-off-by: Dmitry Eremin-Solenikov &lt;dbaryshkov@gmail.com&gt;
Acked-by: Robert Jarzmik &lt;robert.jarzmik@free.fr&gt;
Signed-off-by: Russell King &lt;rmk+kernel@arm.linux.org.uk&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit ef59a20ba375aeb97b3150a118318884743452a8 upstream.

According to the manuals I have, XScale auxiliary register should be
reached with opc_2 = 1 instead of crn = 1. cpu_xscale_proc_init
correctly uses c1, c0, 1 arguments, but cpu_xscale_do_suspend and
cpu_xscale_do_resume use c1, c1, 0. Correct suspend/resume functions to
also use c1, c0, 1.

The issue was primarily noticed thanks to qemu reporing "unsupported
instruction" on the pxa suspend path. Confirmed in PXA210/250 and PXA255
XScale Core manuals and in PXA270 and PXA320 Developers Guides.

Harware tested by me on tosa (pxa255). Robert confirmed on pxa270 board.

Tested-by: Robert Jarzmik &lt;robert.jarzmik@free.fr&gt;
Signed-off-by: Dmitry Eremin-Solenikov &lt;dbaryshkov@gmail.com&gt;
Acked-by: Robert Jarzmik &lt;robert.jarzmik@free.fr&gt;
Signed-off-by: Russell King &lt;rmk+kernel@arm.linux.org.uk&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ARM: 8165/1: alignment: don't break misaligned NEON load/store</title>
<updated>2014-11-05T20:27:46+00:00</updated>
<author>
<name>Robin Murphy</name>
<email>robin.murphy@arm.com</email>
</author>
<published>2014-09-25T10:56:19+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=edeb8f82dff6d09343e0ec195edae6ed19d6423e'/>
<id>edeb8f82dff6d09343e0ec195edae6ed19d6423e</id>
<content type='text'>
commit 5ca918e5e3f9df4634077c06585c42bc6a8d699a upstream.

The alignment fixup incorrectly decodes faulting ARM VLDn/VSTn
instructions (where the optional alignment hint is given but incorrect)
as LDR/STR, leading to register corruption. Detect these and correctly
treat them as unhandled, so that userspace gets the fault it expects.

Reported-by: Simon Hosie &lt;simon.hosie@arm.com&gt;
Signed-off-by: Robin Murphy &lt;robin.murphy@arm.com&gt;
Signed-off-by: Russell King &lt;rmk+kernel@arm.linux.org.uk&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 5ca918e5e3f9df4634077c06585c42bc6a8d699a upstream.

The alignment fixup incorrectly decodes faulting ARM VLDn/VSTn
instructions (where the optional alignment hint is given but incorrect)
as LDR/STR, leading to register corruption. Detect these and correctly
treat them as unhandled, so that userspace gets the fault it expects.

Reported-by: Simon Hosie &lt;simon.hosie@arm.com&gt;
Signed-off-by: Robin Murphy &lt;robin.murphy@arm.com&gt;
Signed-off-by: Russell King &lt;rmk+kernel@arm.linux.org.uk&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ARM: 8129/1: errata: work around Cortex-A15 erratum 830321 using dummy strex</title>
<updated>2014-09-13T22:41:47+00:00</updated>
<author>
<name>Mark Rutland</name>
<email>mark.rutland@arm.com</email>
</author>
<published>2014-08-15T11:11:50+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=bbd4080b5f3f81d5fcedac188cf90f34b7754ebe'/>
<id>bbd4080b5f3f81d5fcedac188cf90f34b7754ebe</id>
<content type='text'>
commit 2c32c65e3726c773760038910be30cce1b4d4149 upstream.

On revisions of Cortex-A15 prior to r3p3, a CLREX instruction at PL1 may
falsely trigger a watchpoint exception, leading to potential data aborts
during exception return and/or livelock.

This patch resolves the issue in the following ways:

  - Replacing our uses of CLREX with a dummy STREX sequence instead (as
    we did for v6 CPUs).

  - Removing the clrex code from v7_exit_coherency_flush and derivatives,
    since this only exists as a minor performance improvement when
    non-cached exclusives are in use (Linux doesn't use these).

Benchmarking on a variety of ARM cores revealed no measurable
performance difference with this change applied, so the change is
performed unconditionally and no new Kconfig entry is added.

Signed-off-by: Mark Rutland &lt;mark.rutland@arm.com&gt;
Signed-off-by: Will Deacon &lt;will.deacon@arm.com&gt;
Signed-off-by: Russell King &lt;rmk+kernel@arm.linux.org.uk&gt;
[bwh: Backported to 3.2:
 - Drop inapplicable changes to arch/arm/include/asm/cacheflush.h and
   arch/arm/mach-exynos/mcpm-exynos.c]
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
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<pre>
commit 2c32c65e3726c773760038910be30cce1b4d4149 upstream.

On revisions of Cortex-A15 prior to r3p3, a CLREX instruction at PL1 may
falsely trigger a watchpoint exception, leading to potential data aborts
during exception return and/or livelock.

This patch resolves the issue in the following ways:

  - Replacing our uses of CLREX with a dummy STREX sequence instead (as
    we did for v6 CPUs).

  - Removing the clrex code from v7_exit_coherency_flush and derivatives,
    since this only exists as a minor performance improvement when
    non-cached exclusives are in use (Linux doesn't use these).

Benchmarking on a variety of ARM cores revealed no measurable
performance difference with this change applied, so the change is
performed unconditionally and no new Kconfig entry is added.

Signed-off-by: Mark Rutland &lt;mark.rutland@arm.com&gt;
Signed-off-by: Will Deacon &lt;will.deacon@arm.com&gt;
Signed-off-by: Russell King &lt;rmk+kernel@arm.linux.org.uk&gt;
[bwh: Backported to 3.2:
 - Drop inapplicable changes to arch/arm/include/asm/cacheflush.h and
   arch/arm/mach-exynos/mcpm-exynos.c]
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</pre>
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