<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/arch/powerpc/kernel/exceptions-64s.S, branch v3.10.72</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>powerpc: Fix hypervisor facility unavaliable vector number</title>
<updated>2013-08-15T05:59:04+00:00</updated>
<author>
<name>Michael Neuling</name>
<email>mikey@neuling.org</email>
</author>
<published>2013-08-09T07:29:27+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=7ab7de87432c7d6544b8c1b45ba6520f4115539f'/>
<id>7ab7de87432c7d6544b8c1b45ba6520f4115539f</id>
<content type='text'>
commit 88f094120bd2f012ff494ae50a8d4e0d8af8f69e upstream.

Currently if we take hypervisor facility unavaliable (from 0xf80/0x4f80) we
mark it as an OS facility unavaliable (0xf60) as the two share the same code
path.

The becomes a problem in facility_unavailable_exception() as we aren't able to
see the hypervisor facility unavailable exceptions.

Below fixes this by duplication the required macros.

Signed-off-by: Michael Neuling &lt;mikey@neuling.org&gt;
Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 88f094120bd2f012ff494ae50a8d4e0d8af8f69e upstream.

Currently if we take hypervisor facility unavaliable (from 0xf80/0x4f80) we
mark it as an OS facility unavaliable (0xf60) as the two share the same code
path.

The becomes a problem in facility_unavailable_exception() as we aren't able to
see the hypervisor facility unavailable exceptions.

Below fixes this by duplication the required macros.

Signed-off-by: Michael Neuling &lt;mikey@neuling.org&gt;
Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc: Wire up the HV facility unavailable exception</title>
<updated>2013-07-25T21:07:21+00:00</updated>
<author>
<name>Michael Ellerman</name>
<email>michael@ellerman.id.au</email>
</author>
<published>2013-06-25T07:47:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=d24966cf890f3b22e379654ba70a38ad9a67d9db'/>
<id>d24966cf890f3b22e379654ba70a38ad9a67d9db</id>
<content type='text'>
commit b14b6260efeee6eb8942c6e6420e31281892acb6 upstream.

Similar to the facility unavailble exception, except the facilities are
controlled by HFSCR.

Adapt the facility_unavailable_exception() so it can be called for
either the regular or Hypervisor facility unavailable exceptions.

Signed-off-by: Michael Ellerman &lt;michael@ellerman.id.au&gt;
Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit b14b6260efeee6eb8942c6e6420e31281892acb6 upstream.

Similar to the facility unavailble exception, except the facilities are
controlled by HFSCR.

Adapt the facility_unavailable_exception() so it can be called for
either the regular or Hypervisor facility unavailable exceptions.

Signed-off-by: Michael Ellerman &lt;michael@ellerman.id.au&gt;
Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc: Rename and flesh out the facility unavailable exception handler</title>
<updated>2013-07-25T21:07:21+00:00</updated>
<author>
<name>Michael Ellerman</name>
<email>michaele@au1.ibm.com</email>
</author>
<published>2013-06-25T07:47:56+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=8e0af91a12c135f6c22e472660f3400d46ed78ac'/>
<id>8e0af91a12c135f6c22e472660f3400d46ed78ac</id>
<content type='text'>
commit 021424a1fce335e05807fd770eb8e1da30a63eea upstream.

The exception at 0xf60 is not the TM (Transactional Memory) unavailable
exception, it is the "Facility Unavailable Exception", rename it as
such.

Flesh out the handler to acknowledge the fact that it can be called for
many reasons, one of which is TM being unavailable.

Use STD_EXCEPTION_COMMON() for the exception body, for some reason we
had it open-coded, I've checked the generated code is identical.

Signed-off-by: Michael Ellerman &lt;michael@ellerman.id.au&gt;
Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 021424a1fce335e05807fd770eb8e1da30a63eea upstream.

The exception at 0xf60 is not the TM (Transactional Memory) unavailable
exception, it is the "Facility Unavailable Exception", rename it as
such.

Flesh out the handler to acknowledge the fact that it can be called for
many reasons, one of which is TM being unavailable.

Use STD_EXCEPTION_COMMON() for the exception body, for some reason we
had it open-coded, I've checked the generated code is identical.

Signed-off-by: Michael Ellerman &lt;michael@ellerman.id.au&gt;
Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc: Remove KVMTEST from RELON exception handlers</title>
<updated>2013-07-25T21:07:21+00:00</updated>
<author>
<name>Michael Ellerman</name>
<email>michael@ellerman.id.au</email>
</author>
<published>2013-06-25T07:47:55+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=77d8caacd2924ca7cbb989c30709503e93c7f026'/>
<id>77d8caacd2924ca7cbb989c30709503e93c7f026</id>
<content type='text'>
commit c9f69518e5f08170bc857984a077f693d63171df upstream.

KVMTEST is a macro which checks whether we are taking an exception from
guest context, if so we branch out of line and eventually call into the
KVM code to handle the switch.

When running real guests on bare metal (HV KVM) the hardware ensures
that we never take a relocation on exception when transitioning from
guest to host. For PR KVM we disable relocation on exceptions ourself in
kvmppc_core_init_vm(), as of commit a413f47 "Disable relocation on
exceptions whenever PR KVM is active".

So convert all the RELON macros to use NOTEST, and drop the remaining
KVM_HANDLER() definitions we have for 0xe40 and 0xe80.

Signed-off-by: Michael Ellerman &lt;michael@ellerman.id.au&gt;
Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit c9f69518e5f08170bc857984a077f693d63171df upstream.

KVMTEST is a macro which checks whether we are taking an exception from
guest context, if so we branch out of line and eventually call into the
KVM code to handle the switch.

When running real guests on bare metal (HV KVM) the hardware ensures
that we never take a relocation on exception when transitioning from
guest to host. For PR KVM we disable relocation on exceptions ourself in
kvmppc_core_init_vm(), as of commit a413f47 "Disable relocation on
exceptions whenever PR KVM is active".

So convert all the RELON macros to use NOTEST, and drop the remaining
KVM_HANDLER() definitions we have for 0xe40 and 0xe80.

Signed-off-by: Michael Ellerman &lt;michael@ellerman.id.au&gt;
Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc: Remove unreachable relocation on exception handlers</title>
<updated>2013-07-25T21:07:21+00:00</updated>
<author>
<name>Michael Ellerman</name>
<email>michael@ellerman.id.au</email>
</author>
<published>2013-06-25T07:47:54+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=497f0957430403bc4e3a0c776da3907fe769b64f'/>
<id>497f0957430403bc4e3a0c776da3907fe769b64f</id>
<content type='text'>
commit 1d567cb4bd42d560a7621cac6f6aebe87343689e upstream.

We have relocation on exception handlers defined for h_data_storage and
h_instr_storage. However we will never take relocation on exceptions for
these because they can only come from a guest, and we never take
relocation on exceptions when we transition from guest to host.

We also have a handler for hmi_exception (Hypervisor Maintenance) which
is defined in the architecture to never be delivered with relocation on,
see see v2.07 Book III-S section 6.5.

So remove the handlers, leaving a branch to self just to be double extra
paranoid.

Signed-off-by: Michael Ellerman &lt;michael@ellerman.id.au&gt;
Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 1d567cb4bd42d560a7621cac6f6aebe87343689e upstream.

We have relocation on exception handlers defined for h_data_storage and
h_instr_storage. However we will never take relocation on exceptions for
these because they can only come from a guest, and we never take
relocation on exceptions when we transition from guest to host.

We also have a handler for hmi_exception (Hypervisor Maintenance) which
is defined in the architecture to never be delivered with relocation on,
see see v2.07 Book III-S section 6.5.

So remove the handlers, leaving a branch to self just to be double extra
paranoid.

Signed-off-by: Michael Ellerman &lt;michael@ellerman.id.au&gt;
Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc: Fix emulation of illegal instructions on PowerNV platform</title>
<updated>2013-06-15T02:24:11+00:00</updated>
<author>
<name>Paul Mackerras</name>
<email>paulus@samba.org</email>
</author>
<published>2013-06-14T10:07:41+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=bf593907f7236e95698a76b7c7a2bbf8b1165327'/>
<id>bf593907f7236e95698a76b7c7a2bbf8b1165327</id>
<content type='text'>
Normally, the kernel emulates a few instructions that are unimplemented
on some processors (e.g. the old dcba instruction), or privileged (e.g.
mfpvr).  The emulation of unimplemented instructions is currently not
working on the PowerNV platform.  The reason is that on these machines,
unimplemented and illegal instructions cause a hypervisor emulation
assist interrupt, rather than a program interrupt as on older CPUs.
Our vector for the emulation assist interrupt just calls
program_check_exception() directly, without setting the bit in SRR1
that indicates an illegal instruction interrupt.  This fixes it by
making the emulation assist interrupt set that bit before calling
program_check_interrupt().  With this, old programs that use no-longer
implemented instructions such as dcba now work again.

CC: &lt;stable@vger.kernel.org&gt;
Signed-off-by: Paul Mackerras &lt;paulus@samba.org&gt;
Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Normally, the kernel emulates a few instructions that are unimplemented
on some processors (e.g. the old dcba instruction), or privileged (e.g.
mfpvr).  The emulation of unimplemented instructions is currently not
working on the PowerNV platform.  The reason is that on these machines,
unimplemented and illegal instructions cause a hypervisor emulation
assist interrupt, rather than a program interrupt as on older CPUs.
Our vector for the emulation assist interrupt just calls
program_check_exception() directly, without setting the bit in SRR1
that indicates an illegal instruction interrupt.  This fixes it by
making the emulation assist interrupt set that bit before calling
program_check_interrupt().  With this, old programs that use no-longer
implemented instructions such as dcba now work again.

CC: &lt;stable@vger.kernel.org&gt;
Signed-off-by: Paul Mackerras &lt;paulus@samba.org&gt;
Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc/power8: Update denormalization handler</title>
<updated>2013-06-09T22:36:26+00:00</updated>
<author>
<name>Michael Neuling</name>
<email>mikey@neuling.org</email>
</author>
<published>2013-05-29T21:33:19+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=fb0fce3e554e5513aaa1c1c52b2ece11feea3c7d'/>
<id>fb0fce3e554e5513aaa1c1c52b2ece11feea3c7d</id>
<content type='text'>
POWER8 can take a denormalisation exception on any VSX registers.

This does the extra 32 VSX registers we don't currently handle.

Signed-off-by: Michael Neuling &lt;mikey@neuling.org&gt;
Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
POWER8 can take a denormalisation exception on any VSX registers.

This does the extra 32 VSX registers we don't currently handle.

Signed-off-by: Michael Neuling &lt;mikey@neuling.org&gt;
Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc/pseries: Simplify denormalization handler</title>
<updated>2013-06-09T22:36:22+00:00</updated>
<author>
<name>Michael Neuling</name>
<email>mikey@neuling.org</email>
</author>
<published>2013-05-29T21:33:18+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=d7c67fb1cf00b84829ae06fca04ad39408f156ba'/>
<id>d7c67fb1cf00b84829ae06fca04ad39408f156ba</id>
<content type='text'>
The following simplifies the denorm code by using macros to generate the long
stream of almost identical instructions.

This patch results in no changes to the output binary, but removes a lot of
lines of code.

Signed-off-by: Michael Neuling &lt;mikey@neuling.org&gt;
Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The following simplifies the denorm code by using macros to generate the long
stream of almost identical instructions.

This patch results in no changes to the output binary, but removes a lot of
lines of code.

Signed-off-by: Michael Neuling &lt;mikey@neuling.org&gt;
Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc: Save DAR and DSISR in pt_regs on MCE</title>
<updated>2013-04-30T05:59:42+00:00</updated>
<author>
<name>Aneesh Kumar K.V</name>
<email>aneesh.kumar@linux.vnet.ibm.com</email>
</author>
<published>2013-04-28T09:37:26+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=ce54152f429ed5e6ad83e5e9f61825b5a795dd1e'/>
<id>ce54152f429ed5e6ad83e5e9f61825b5a795dd1e</id>
<content type='text'>
We were not saving DAR and DSISR on MCE. Save then and also print the values
along with exception details in xmon.

Acked-by: Paul Mackerras &lt;paulus@samba.org&gt;
Signed-off-by: Aneesh Kumar K.V &lt;aneesh.kumar@linux.vnet.ibm.com&gt;
Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
We were not saving DAR and DSISR on MCE. Save then and also print the values
along with exception details in xmon.

Acked-by: Paul Mackerras &lt;paulus@samba.org&gt;
Signed-off-by: Aneesh Kumar K.V &lt;aneesh.kumar@linux.vnet.ibm.com&gt;
Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc: Fix "attempt to move .org backwards" error</title>
<updated>2013-04-26T06:08:27+00:00</updated>
<author>
<name>Paul Mackerras</name>
<email>paulus@samba.org</email>
</author>
<published>2013-04-25T17:51:40+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=a485c70989fc6e1b002ea8c323bc3fc2f1eab722'/>
<id>a485c70989fc6e1b002ea8c323bc3fc2f1eab722</id>
<content type='text'>
Building a 64-bit powerpc kernel with PR KVM enabled currently gives
this error:

  AS      arch/powerpc/kernel/head_64.o
arch/powerpc/kernel/exceptions-64s.S: Assembler messages:
arch/powerpc/kernel/exceptions-64s.S:258: Error: attempt to move .org backwards
make[2]: *** [arch/powerpc/kernel/head_64.o] Error 1

This happens because the MASKABLE_EXCEPTION_PSERIES macro turns into
33 instructions, but we only have space for 32 at the decrementer
interrupt vector (from 0x900 to 0x980).

In the code generated by the MASKABLE_EXCEPTION_PSERIES macro, we
currently have two instances of the HMT_MEDIUM macro, which has the
effect of setting the SMT thread priority to medium.  One is the
first instruction, and is overwritten by a no-op on processors where
we save the PPR (processor priority register), that is, POWER7 or
later.  The other is after we have saved the PPR.

In order to reduce the code at 0x900 by one instruction, we omit the
first HMT_MEDIUM.  On processors without SMT this will have no effect
since HMT_MEDIUM is a no-op there.  On POWER5 and RS64 machines this
will mean that the first few instructions take a little longer in the
case where a decrementer interrupt occurs when the hardware thread is
running at low SMT priority.  On POWER6 and later machines, the
hardware automatically boosts the thread priority when a decrementer
interrupt is taken if the thread priority was below medium, so this
change won't make any difference.

The alternative would be to branch out of line after saving the CFAR.
However, that would incur an extra overhead on all processors, whereas
the approach adopted here only adds overhead on older threaded processors.

Signed-off-by: Paul Mackerras &lt;paulus@samba.org&gt;
Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Building a 64-bit powerpc kernel with PR KVM enabled currently gives
this error:

  AS      arch/powerpc/kernel/head_64.o
arch/powerpc/kernel/exceptions-64s.S: Assembler messages:
arch/powerpc/kernel/exceptions-64s.S:258: Error: attempt to move .org backwards
make[2]: *** [arch/powerpc/kernel/head_64.o] Error 1

This happens because the MASKABLE_EXCEPTION_PSERIES macro turns into
33 instructions, but we only have space for 32 at the decrementer
interrupt vector (from 0x900 to 0x980).

In the code generated by the MASKABLE_EXCEPTION_PSERIES macro, we
currently have two instances of the HMT_MEDIUM macro, which has the
effect of setting the SMT thread priority to medium.  One is the
first instruction, and is overwritten by a no-op on processors where
we save the PPR (processor priority register), that is, POWER7 or
later.  The other is after we have saved the PPR.

In order to reduce the code at 0x900 by one instruction, we omit the
first HMT_MEDIUM.  On processors without SMT this will have no effect
since HMT_MEDIUM is a no-op there.  On POWER5 and RS64 machines this
will mean that the first few instructions take a little longer in the
case where a decrementer interrupt occurs when the hardware thread is
running at low SMT priority.  On POWER6 and later machines, the
hardware automatically boosts the thread priority when a decrementer
interrupt is taken if the thread priority was below medium, so this
change won't make any difference.

The alternative would be to branch out of line after saving the CFAR.
However, that would incur an extra overhead on all processors, whereas
the approach adopted here only adds overhead on older threaded processors.

Signed-off-by: Paul Mackerras &lt;paulus@samba.org&gt;
Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
