<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/arch/arm64/kernel/cpu_errata.c, branch v4.20</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>arm64: Add workaround for Cortex-A76 erratum 1286807</title>
<updated>2018-11-29T16:45:45+00:00</updated>
<author>
<name>Catalin Marinas</name>
<email>catalin.marinas@arm.com</email>
</author>
<published>2018-11-19T11:27:28+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=ce8c80c536dac9f325a051b30bf7730ee505eddc'/>
<id>ce8c80c536dac9f325a051b30bf7730ee505eddc</id>
<content type='text'>
On the affected Cortex-A76 cores (r0p0 to r3p0), if a virtual address
for a cacheable mapping of a location is being accessed by a core while
another core is remapping the virtual address to a new physical page
using the recommended break-before-make sequence, then under very rare
circumstances TLBI+DSB completes before a read using the translation
being invalidated has been observed by other observers. The workaround
repeats the TLBI+DSB operation and is shared with the Qualcomm Falkor
erratum 1009

Reviewed-by: Suzuki K Poulose &lt;suzuki.poulose@arm.com&gt;
Signed-off-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
On the affected Cortex-A76 cores (r0p0 to r3p0), if a virtual address
for a cacheable mapping of a location is being accessed by a core while
another core is remapping the virtual address to a new physical page
using the recommended break-before-make sequence, then under very rare
circumstances TLBI+DSB completes before a read using the translation
being invalidated has been observed by other observers. The workaround
repeats the TLBI+DSB operation and is shared with the Qualcomm Falkor
erratum 1009

Reviewed-by: Suzuki K Poulose &lt;suzuki.poulose@arm.com&gt;
Signed-off-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>arm64: KVM: Guests can skip __install_bp_hardening_cb()s HYP work</title>
<updated>2018-10-19T14:37:25+00:00</updated>
<author>
<name>James Morse</name>
<email>james.morse@arm.com</email>
</author>
<published>2018-09-21T20:49:19+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=4debef5510071032c6d5dace31ca1cc42a120073'/>
<id>4debef5510071032c6d5dace31ca1cc42a120073</id>
<content type='text'>
enable_smccc_arch_workaround_1() passes NULL as the hyp_vecs start and
end if the HVC conduit is in use, and ARM_SMCCC_ARCH_WORKAROUND_1 is
detected.

If the guest kernel happened to be built with KVM_INDIRECT_VECTORS,
we go on to allocate a slot, memcpy() the empty workaround in and
do the appropriate cache maintenance.

This works as we always tell memcpy() the range is 0, so it never
accesses the NULL src pointer, but we still do the cache maintenance.

If hyp_vecs_start is NULL we know we're a guest, just update the fn
like the !KVM_INDIRECT_VECTORS version.

Reviewed-by: Julien Thierry &lt;julien.thierry@arm.com&gt;
Acked-by: Marc Zyngier &lt;marc.zyngier@arm.com&gt;
Signed-off-by: James Morse &lt;james.morse@arm.com&gt;
Signed-off-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
enable_smccc_arch_workaround_1() passes NULL as the hyp_vecs start and
end if the HVC conduit is in use, and ARM_SMCCC_ARCH_WORKAROUND_1 is
detected.

If the guest kernel happened to be built with KVM_INDIRECT_VECTORS,
we go on to allocate a slot, memcpy() the empty workaround in and
do the appropriate cache maintenance.

This works as we always tell memcpy() the range is 0, so it never
accesses the NULL src pointer, but we still do the cache maintenance.

If hyp_vecs_start is NULL we know we're a guest, just update the fn
like the !KVM_INDIRECT_VECTORS version.

Reviewed-by: Julien Thierry &lt;julien.thierry@arm.com&gt;
Acked-by: Marc Zyngier &lt;marc.zyngier@arm.com&gt;
Signed-off-by: James Morse &lt;james.morse@arm.com&gt;
Signed-off-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>arm64: cpufeature: Trap CTR_EL0 access only where it is necessary</title>
<updated>2018-10-16T10:53:34+00:00</updated>
<author>
<name>Suzuki K Poulose</name>
<email>suzuki.poulose@arm.com</email>
</author>
<published>2018-10-09T13:47:07+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=4afe8e79da920bdf6698b01bc668fffc6758f37b'/>
<id>4afe8e79da920bdf6698b01bc668fffc6758f37b</id>
<content type='text'>
When there is a mismatch in the CTR_EL0 field, we trap
access to CTR from EL0 on all CPUs to expose the safe
value. However, we could skip trapping on a CPU which
matches the safe value.

Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Will Deacon &lt;will.deacon@arm.com&gt;
Signed-off-by: Suzuki K Poulose &lt;suzuki.poulose@arm.com&gt;
Signed-off-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
When there is a mismatch in the CTR_EL0 field, we trap
access to CTR from EL0 on all CPUs to expose the safe
value. However, we could skip trapping on a CPU which
matches the safe value.

Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Will Deacon &lt;will.deacon@arm.com&gt;
Signed-off-by: Suzuki K Poulose &lt;suzuki.poulose@arm.com&gt;
Signed-off-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>arm64: cpufeature: Fix handling of CTR_EL0.IDC field</title>
<updated>2018-10-16T10:53:31+00:00</updated>
<author>
<name>Suzuki K Poulose</name>
<email>suzuki.poulose@arm.com</email>
</author>
<published>2018-10-09T13:47:06+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=1602df02f33f61fe0de1bbfeba0d1c97c14bff19'/>
<id>1602df02f33f61fe0de1bbfeba0d1c97c14bff19</id>
<content type='text'>
CTR_EL0.IDC reports the data cache clean requirements for instruction
to data coherence. However, if the field is 0, we need to check the
CLIDR_EL1 fields to detect the status of the feature. Currently we
don't do this and generate a warning with tainting the kernel, when
there is a mismatch in the field among the CPUs. Also the userspace
doesn't have a reliable way to check the CLIDR_EL1 register to check
the status.

This patch fixes the problem by checking the CLIDR_EL1 fields, when
(CTR_EL0.IDC == 0) and updates the kernel's copy of the CTR_EL0 for
the CPU with the actual status of the feature. This would allow the
sanity check infrastructure to do the proper checking of the fields
and also allow the CTR_EL0 emulation code to supply the real status
of the feature.

Now, if a CPU has raw CTR_EL0.IDC == 0 and effective IDC == 1 (with
overall system wide IDC == 1), we need to expose the real value to
the user. So, we trap CTR_EL0 access on the CPU which reports incorrect
CTR_EL0.IDC.

Fixes: commit 6ae4b6e057888 ("arm64: Add support for new control bits CTR_EL0.DIC and CTR_EL0.IDC")
Cc: Shanker Donthineni &lt;shankerd@codeaurora.org&gt;
Cc: Philip Elcan &lt;pelcan@codeaurora.org&gt;
Cc: Will Deacon &lt;will.deacon@arm.com&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Signed-off-by: Suzuki K Poulose &lt;suzuki.poulose@arm.com&gt;
Signed-off-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
CTR_EL0.IDC reports the data cache clean requirements for instruction
to data coherence. However, if the field is 0, we need to check the
CLIDR_EL1 fields to detect the status of the feature. Currently we
don't do this and generate a warning with tainting the kernel, when
there is a mismatch in the field among the CPUs. Also the userspace
doesn't have a reliable way to check the CLIDR_EL1 register to check
the status.

This patch fixes the problem by checking the CLIDR_EL1 fields, when
(CTR_EL0.IDC == 0) and updates the kernel's copy of the CTR_EL0 for
the CPU with the actual status of the feature. This would allow the
sanity check infrastructure to do the proper checking of the fields
and also allow the CTR_EL0 emulation code to supply the real status
of the feature.

Now, if a CPU has raw CTR_EL0.IDC == 0 and effective IDC == 1 (with
overall system wide IDC == 1), we need to expose the real value to
the user. So, we trap CTR_EL0 access on the CPU which reports incorrect
CTR_EL0.IDC.

Fixes: commit 6ae4b6e057888 ("arm64: Add support for new control bits CTR_EL0.DIC and CTR_EL0.IDC")
Cc: Shanker Donthineni &lt;shankerd@codeaurora.org&gt;
Cc: Philip Elcan &lt;pelcan@codeaurora.org&gt;
Cc: Will Deacon &lt;will.deacon@arm.com&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Signed-off-by: Suzuki K Poulose &lt;suzuki.poulose@arm.com&gt;
Signed-off-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>arm64: arch_timer: Add workaround for ARM erratum 1188873</title>
<updated>2018-10-01T12:38:47+00:00</updated>
<author>
<name>Marc Zyngier</name>
<email>marc.zyngier@arm.com</email>
</author>
<published>2018-09-27T16:15:34+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=95b861a4a6d94f64d5242605569218160ebacdbe'/>
<id>95b861a4a6d94f64d5242605569218160ebacdbe</id>
<content type='text'>
When running on Cortex-A76, a timer access from an AArch32 EL0
task may end up with a corrupted value or register. The workaround for
this is to trap these accesses at EL1/EL2 and execute them there.

This only affects versions r0p0, r1p0 and r2p0 of the CPU.

Acked-by: Mark Rutland &lt;mark.rutland@arm.com&gt;
Signed-off-by: Marc Zyngier &lt;marc.zyngier@arm.com&gt;
Signed-off-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
When running on Cortex-A76, a timer access from an AArch32 EL0
task may end up with a corrupted value or register. The workaround for
this is to trap these accesses at EL1/EL2 and execute them there.

This only affects versions r0p0, r1p0 and r2p0 of the CPU.

Acked-by: Mark Rutland &lt;mark.rutland@arm.com&gt;
Signed-off-by: Marc Zyngier &lt;marc.zyngier@arm.com&gt;
Signed-off-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>arm64: cpu_errata: Remove ARM64_MISMATCHED_CACHE_LINE_SIZE</title>
<updated>2018-09-19T17:21:49+00:00</updated>
<author>
<name>Will Deacon</name>
<email>will.deacon@arm.com</email>
</author>
<published>2018-09-19T10:41:21+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=880f7cc47265e7b195781dfa9a0cd62ef78304e3'/>
<id>880f7cc47265e7b195781dfa9a0cd62ef78304e3</id>
<content type='text'>
There's no need to treat mismatched cache-line sizes reported by CTR_EL0
differently to any other mismatched fields that we treat as "STRICT" in
the cpufeature code. In both cases we need to trap and emulate EL0
accesses to the register, so drop ARM64_MISMATCHED_CACHE_LINE_SIZE and
rely on ARM64_MISMATCHED_CACHE_TYPE instead.

Reviewed-by: Suzuki K Poulose &lt;suzuki.poulose@arm.com&gt;
Signed-off-by: Will Deacon &lt;will.deacon@arm.com&gt;
[catalin.marinas@arm.com: move ARM64_HAS_CNP in the empty cpucaps.h slot]
Signed-off-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
There's no need to treat mismatched cache-line sizes reported by CTR_EL0
differently to any other mismatched fields that we treat as "STRICT" in
the cpufeature code. In both cases we need to trap and emulate EL0
accesses to the register, so drop ARM64_MISMATCHED_CACHE_LINE_SIZE and
rely on ARM64_MISMATCHED_CACHE_TYPE instead.

Reviewed-by: Suzuki K Poulose &lt;suzuki.poulose@arm.com&gt;
Signed-off-by: Will Deacon &lt;will.deacon@arm.com&gt;
[catalin.marinas@arm.com: move ARM64_HAS_CNP in the empty cpucaps.h slot]
Signed-off-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>arm64: cpu: Move errata and feature enable callbacks closer to callers</title>
<updated>2018-09-14T16:46:22+00:00</updated>
<author>
<name>Will Deacon</name>
<email>will.deacon@arm.com</email>
</author>
<published>2018-08-07T12:53:41+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=b8925ee2e12d1cb9a11d6f28b5814f2bfa59dce1'/>
<id>b8925ee2e12d1cb9a11d6f28b5814f2bfa59dce1</id>
<content type='text'>
The cpu errata and feature enable callbacks are only called via their
respective arm64_cpu_capabilities structure and therefore shouldn't
exist in the global namespace.

Move the PAN, RAS and cache maintenance emulation enable callbacks into
the same files as their corresponding arm64_cpu_capabilities structures,
making them static in the process.

Signed-off-by: Will Deacon &lt;will.deacon@arm.com&gt;
Signed-off-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The cpu errata and feature enable callbacks are only called via their
respective arm64_cpu_capabilities structure and therefore shouldn't
exist in the global namespace.

Move the PAN, RAS and cache maintenance emulation enable callbacks into
the same files as their corresponding arm64_cpu_capabilities structures,
making them static in the process.

Signed-off-by: Will Deacon &lt;will.deacon@arm.com&gt;
Signed-off-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>arm64: ssbd: Add support for PSTATE.SSBS rather than trapping to EL3</title>
<updated>2018-09-14T16:46:19+00:00</updated>
<author>
<name>Will Deacon</name>
<email>will.deacon@arm.com</email>
</author>
<published>2018-08-07T12:47:06+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=8f04e8e6e29c93421a95b61cad62e3918425eac7'/>
<id>8f04e8e6e29c93421a95b61cad62e3918425eac7</id>
<content type='text'>
On CPUs with support for PSTATE.SSBS, the kernel can toggle the SSBD
state without needing to call into firmware.

This patch hooks into the existing SSBD infrastructure so that SSBS is
used on CPUs that support it, but it's all made horribly complicated by
the very real possibility of big/little systems that don't uniformly
provide the new capability.

Signed-off-by: Will Deacon &lt;will.deacon@arm.com&gt;
Signed-off-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
On CPUs with support for PSTATE.SSBS, the kernel can toggle the SSBD
state without needing to call into firmware.

This patch hooks into the existing SSBD infrastructure so that SSBS is
used on CPUs that support it, but it's all made horribly complicated by
the very real possibility of big/little systems that don't uniformly
provide the new capability.

Signed-off-by: Will Deacon &lt;will.deacon@arm.com&gt;
Signed-off-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>arm64: kill config_sctlr_el1()</title>
<updated>2018-07-12T13:40:38+00:00</updated>
<author>
<name>Mark Rutland</name>
<email>mark.rutland@arm.com</email>
</author>
<published>2018-07-11T13:56:38+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=25be597ada0b49d2748ab520a78a28c1764d69e4'/>
<id>25be597ada0b49d2748ab520a78a28c1764d69e4</id>
<content type='text'>
Now that we have sysreg_clear_set(), we can consistently use this
instead of config_sctlr_el1().

Signed-off-by: Mark Rutland &lt;mark.rutland@arm.com&gt;
Reviewed-by: Dave Martin &lt;dave.martin@arm.com&gt;
Acked-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Cc: James Morse &lt;james.morse@arm.com&gt;
Cc: Will Deacon &lt;will.deacon@arm.com&gt;
Signed-off-by: Will Deacon &lt;will.deacon@arm.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Now that we have sysreg_clear_set(), we can consistently use this
instead of config_sctlr_el1().

Signed-off-by: Mark Rutland &lt;mark.rutland@arm.com&gt;
Reviewed-by: Dave Martin &lt;dave.martin@arm.com&gt;
Acked-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Cc: James Morse &lt;james.morse@arm.com&gt;
Cc: Will Deacon &lt;will.deacon@arm.com&gt;
Signed-off-by: Will Deacon &lt;will.deacon@arm.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>arm64: errata: Don't define type field twice for arm64_errata[] entries</title>
<updated>2018-07-06T12:17:25+00:00</updated>
<author>
<name>Will Deacon</name>
<email>will.deacon@arm.com</email>
</author>
<published>2018-07-06T08:57:45+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=178909a669584b97e9154375df2126fd93b6306c'/>
<id>178909a669584b97e9154375df2126fd93b6306c</id>
<content type='text'>
The ERRATA_MIDR_REV_RANGE macro assigns ARM64_CPUCAP_LOCAL_CPU_ERRATUM
to the '.type' field of the 'struct arm64_cpu_capabilities', so there's
no need to assign it explicitly as well.

Signed-off-by: Will Deacon &lt;will.deacon@arm.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The ERRATA_MIDR_REV_RANGE macro assigns ARM64_CPUCAP_LOCAL_CPU_ERRATUM
to the '.type' field of the 'struct arm64_cpu_capabilities', so there's
no need to assign it explicitly as well.

Signed-off-by: Will Deacon &lt;will.deacon@arm.com&gt;
</pre>
</div>
</content>
</entry>
</feed>
