<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/arch/mips/kernel/cpu-probe.c, branch v5.4-rc2</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>MIPS: Treat Loongson Extensions as ASEs</title>
<updated>2019-08-26T10:42:40+00:00</updated>
<author>
<name>Jiaxun Yang</name>
<email>jiaxun.yang@flygoat.com</email>
</author>
<published>2019-05-29T08:42:59+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=d2f965549006acb865c4638f1f030ebcefdc71f6'/>
<id>d2f965549006acb865c4638f1f030ebcefdc71f6</id>
<content type='text'>
Recently, binutils had split Loongson-3 Extensions into four ASEs:
MMI, CAM, EXT, EXT2. This patch do the samething in kernel and expose
them in cpuinfo so applications can probe supported ASEs at runtime.

Signed-off-by: Jiaxun Yang &lt;jiaxun.yang@flygoat.com&gt;
Cc: Huacai Chen &lt;chenhc@lemote.com&gt;
Cc: Yunqiang Su &lt;ysu@wavecomp.com&gt;
Cc: stable@vger.kernel.org # v4.14+
Signed-off-by: Paul Burton &lt;paul.burton@mips.com&gt;
Cc: linux-mips@vger.kernel.org
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Recently, binutils had split Loongson-3 Extensions into four ASEs:
MMI, CAM, EXT, EXT2. This patch do the samething in kernel and expose
them in cpuinfo so applications can probe supported ASEs at runtime.

Signed-off-by: Jiaxun Yang &lt;jiaxun.yang@flygoat.com&gt;
Cc: Huacai Chen &lt;chenhc@lemote.com&gt;
Cc: Yunqiang Su &lt;ysu@wavecomp.com&gt;
Cc: stable@vger.kernel.org # v4.14+
Signed-off-by: Paul Burton &lt;paul.burton@mips.com&gt;
Cc: linux-mips@vger.kernel.org
</pre>
</div>
</content>
</entry>
<entry>
<title>MIPS: Ingenic: Disable broken BTB lookup optimization.</title>
<updated>2019-08-06T01:30:45+00:00</updated>
<author>
<name>Zhou Yanjie</name>
<email>zhouyanjie@zoho.com</email>
</author>
<published>2019-08-02T08:27:37+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=053951dda71ecb4b554a2cdbe26f5f6f9bee9dd2'/>
<id>053951dda71ecb4b554a2cdbe26f5f6f9bee9dd2</id>
<content type='text'>
In order to further reduce power consumption, the XBurst core
by default attempts to avoid branch target buffer lookups by
detecting &amp; special casing loops. This feature will cause
BogoMIPS and lpj calculate in error. Set cp0 config7 bit 4 to
disable this feature.

Signed-off-by: Zhou Yanjie &lt;zhouyanjie@zoho.com&gt;
Signed-off-by: Paul Burton &lt;paul.burton@mips.com&gt;
Cc: linux-mips@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: ralf@linux-mips.org
Cc: paul@crapouillou.net
Cc: jhogan@kernel.org
Cc: malat@debian.org
Cc: gregkh@linuxfoundation.org
Cc: tglx@linutronix.de
Cc: allison@lohutok.net
Cc: syq@debian.org
Cc: chenhc@lemote.com
Cc: jiaxun.yang@flygoat.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
In order to further reduce power consumption, the XBurst core
by default attempts to avoid branch target buffer lookups by
detecting &amp; special casing loops. This feature will cause
BogoMIPS and lpj calculate in error. Set cp0 config7 bit 4 to
disable this feature.

Signed-off-by: Zhou Yanjie &lt;zhouyanjie@zoho.com&gt;
Signed-off-by: Paul Burton &lt;paul.burton@mips.com&gt;
Cc: linux-mips@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: ralf@linux-mips.org
Cc: paul@crapouillou.net
Cc: jhogan@kernel.org
Cc: malat@debian.org
Cc: gregkh@linuxfoundation.org
Cc: tglx@linutronix.de
Cc: allison@lohutok.net
Cc: syq@debian.org
Cc: chenhc@lemote.com
Cc: jiaxun.yang@flygoat.com
</pre>
</div>
</content>
</entry>
<entry>
<title>MIPS: Remove unused R8000 CPU support</title>
<updated>2019-07-23T21:33:51+00:00</updated>
<author>
<name>Paul Burton</name>
<email>paul.burton@mips.com</email>
</author>
<published>2019-07-22T22:00:03+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=c2aeaaea175652af6610f97a0de6d7cd07311e18'/>
<id>c2aeaaea175652af6610f97a0de6d7cd07311e18</id>
<content type='text'>
Our R8000 CPU support can only be included if a system selects
CONFIG_SYS_HAS_CPU_R8000. No system does, making all R8000-related CPU
support dead code. Remove it.

Signed-off-by: Paul Burton &lt;paul.burton@mips.com&gt;
Cc: linux-mips@vger.kernel.org
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Our R8000 CPU support can only be included if a system selects
CONFIG_SYS_HAS_CPU_R8000. No system does, making all R8000-related CPU
support dead code. Remove it.

Signed-off-by: Paul Burton &lt;paul.burton@mips.com&gt;
Cc: linux-mips@vger.kernel.org
</pre>
</div>
</content>
</entry>
<entry>
<title>MIPS: Remove unused R5432 CPU support</title>
<updated>2019-07-23T21:33:34+00:00</updated>
<author>
<name>Paul Burton</name>
<email>paul.burton@mips.com</email>
</author>
<published>2019-07-22T21:59:50+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=8e96b08472e6698011d3105912031e90e7ef553f'/>
<id>8e96b08472e6698011d3105912031e90e7ef553f</id>
<content type='text'>
Our R5432 CPU support can only be included if a system selects
CONFIG_SYS_HAS_CPU_R5432. No system does, making all R5432-related CPU
support dead code. Remove it.

Signed-off-by: Paul Burton &lt;paul.burton@mips.com&gt;
Cc: linux-mips@vger.kernel.org
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Our R5432 CPU support can only be included if a system selects
CONFIG_SYS_HAS_CPU_R5432. No system does, making all R5432-related CPU
support dead code. Remove it.

Signed-off-by: Paul Burton &lt;paul.burton@mips.com&gt;
Cc: linux-mips@vger.kernel.org
</pre>
</div>
</content>
</entry>
<entry>
<title>MIPS: Remove unused R4300 CPU support</title>
<updated>2019-07-23T21:33:23+00:00</updated>
<author>
<name>Paul Burton</name>
<email>paul.burton@mips.com</email>
</author>
<published>2019-07-22T21:59:43+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=f9065b54d437c4660e3d974ad9ce5188c068cd76'/>
<id>f9065b54d437c4660e3d974ad9ce5188c068cd76</id>
<content type='text'>
Our R4300 CPU support can only be included if a system selects
CONFIG_SYS_HAS_CPU_R4300. No system does, making all R4300-related CPU
support dead code. Remove it.

Signed-off-by: Paul Burton &lt;paul.burton@mips.com&gt;
Cc: linux-mips@vger.kernel.org
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Our R4300 CPU support can only be included if a system selects
CONFIG_SYS_HAS_CPU_R4300. No system does, making all R4300-related CPU
support dead code. Remove it.

Signed-off-by: Paul Burton &lt;paul.burton@mips.com&gt;
Cc: linux-mips@vger.kernel.org
</pre>
</div>
</content>
</entry>
<entry>
<title>MIPS: Decode config3 register on Ingenic SoCs</title>
<updated>2019-07-21T22:23:24+00:00</updated>
<author>
<name>Paul Cercueil</name>
<email>paul@crapouillou.net</email>
</author>
<published>2019-05-07T22:43:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=368fb26c1e55a187131a794f95420d96d31d0e5e'/>
<id>368fb26c1e55a187131a794f95420d96d31d0e5e</id>
<content type='text'>
XBurst misses a config2 register, so config3 decode was skipped in
decode_configs().

Signed-off-by: Paul Cercueil &lt;paul@crapouillou.net&gt;
Signed-off-by: Paul Burton &lt;paul.burton@mips.com&gt;
Cc: Ralf Baechle &lt;ralf@linux-mips.org&gt;
Cc: James Hogan &lt;jhogan@kernel.org&gt;
Cc: od@zcrc.me
Cc: linux-mips@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
XBurst misses a config2 register, so config3 decode was skipped in
decode_configs().

Signed-off-by: Paul Cercueil &lt;paul@crapouillou.net&gt;
Signed-off-by: Paul Burton &lt;paul.burton@mips.com&gt;
Cc: Ralf Baechle &lt;ralf@linux-mips.org&gt;
Cc: James Hogan &lt;jhogan@kernel.org&gt;
Cc: od@zcrc.me
Cc: linux-mips@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
</pre>
</div>
</content>
</entry>
<entry>
<title>MIPS: Rename JZRISC to XBURST</title>
<updated>2019-07-21T22:23:23+00:00</updated>
<author>
<name>Paul Cercueil</name>
<email>paul@crapouillou.net</email>
</author>
<published>2019-05-07T22:43:56+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=3b25b763116482596227225bea7c03fcde11c9ed'/>
<id>3b25b763116482596227225bea7c03fcde11c9ed</id>
<content type='text'>
The real name of the CPU present in the JZ line of SoCs from Ingenic is
XBurst, not JZRISC.

Signed-off-by: Paul Cercueil &lt;paul@crapouillou.net&gt;
[paul.burton@mips.com: Leave /proc/cpuinfo string as-is.]
Signed-off-by: Paul Burton &lt;paul.burton@mips.com&gt;
Cc: Ralf Baechle &lt;ralf@linux-mips.org&gt;
Cc: James Hogan &lt;jhogan@kernel.org&gt;
Cc: od@zcrc.me
Cc: linux-mips@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The real name of the CPU present in the JZ line of SoCs from Ingenic is
XBurst, not JZRISC.

Signed-off-by: Paul Cercueil &lt;paul@crapouillou.net&gt;
[paul.burton@mips.com: Leave /proc/cpuinfo string as-is.]
Signed-off-by: Paul Burton &lt;paul.burton@mips.com&gt;
Cc: Ralf Baechle &lt;ralf@linux-mips.org&gt;
Cc: James Hogan &lt;jhogan@kernel.org&gt;
Cc: od@zcrc.me
Cc: linux-mips@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
</pre>
</div>
</content>
</entry>
<entry>
<title>treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152</title>
<updated>2019-05-30T18:26:32+00:00</updated>
<author>
<name>Thomas Gleixner</name>
<email>tglx@linutronix.de</email>
</author>
<published>2019-05-27T06:55:01+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=2874c5fd284268364ece81a7bd936f3c8168e567'/>
<id>2874c5fd284268364ece81a7bd936f3c8168e567</id>
<content type='text'>
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Reviewed-by: Allison Randal &lt;allison@lohutok.net&gt;
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Reviewed-by: Allison Randal &lt;allison@lohutok.net&gt;
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>MIPS: Fix Ingenic SoCs sometimes reporting wrong ISA</title>
<updated>2019-05-09T23:39:27+00:00</updated>
<author>
<name>Paul Cercueil</name>
<email>paul@crapouillou.net</email>
</author>
<published>2019-05-07T22:17:55+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=8041edb5920902adc9b28f2fcd9ccce395434ead'/>
<id>8041edb5920902adc9b28f2fcd9ccce395434ead</id>
<content type='text'>
The config0 register in the Xburst CPUs with a processor ID of
PRID_COMP_INGENIC_D0 report themselves as MIPS32r2 compatible,
but they don't actually support this ISA.

Signed-off-by: Paul Cercueil &lt;paul@crapouillou.net&gt;
Signed-off-by: Paul Burton &lt;paul.burton@mips.com&gt;
Cc: Ralf Baechle &lt;ralf@linux-mips.org&gt;
Cc: James Hogan &lt;jhogan@kernel.org&gt;
Cc: od@zcrc.me
Cc: linux-mips@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The config0 register in the Xburst CPUs with a processor ID of
PRID_COMP_INGENIC_D0 report themselves as MIPS32r2 compatible,
but they don't actually support this ISA.

Signed-off-by: Paul Cercueil &lt;paul@crapouillou.net&gt;
Signed-off-by: Paul Burton &lt;paul.burton@mips.com&gt;
Cc: Ralf Baechle &lt;ralf@linux-mips.org&gt;
Cc: James Hogan &lt;jhogan@kernel.org&gt;
Cc: od@zcrc.me
Cc: linux-mips@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
</pre>
</div>
</content>
</entry>
<entry>
<title>MIPS: MemoryMapID (MMID) Support</title>
<updated>2019-02-04T18:56:41+00:00</updated>
<author>
<name>Paul Burton</name>
<email>paul.burton@mips.com</email>
</author>
<published>2019-02-02T01:43:28+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=c8790d657b0a8d42801fb4536f6f106b4b6306e8'/>
<id>c8790d657b0a8d42801fb4536f6f106b4b6306e8</id>
<content type='text'>
Introduce support for using MemoryMapIDs (MMIDs) as an alternative to
Address Space IDs (ASIDs). The major difference between the two is that
MMIDs are global - ie. an MMID uniquely identifies an address space
across all coherent CPUs. In contrast ASIDs are non-global per-CPU IDs,
wherein each address space is allocated a separate ASID for each CPU
upon which it is used. This global namespace allows a new GINVT
instruction be used to globally invalidate TLB entries associated with a
particular MMID across all coherent CPUs in the system, removing the
need for IPIs to invalidate entries with separate ASIDs on each CPU.

The allocation scheme used here is largely borrowed from arm64 (see
arch/arm64/mm/context.c). In essence we maintain a bitmap to track
available MMIDs, and MMIDs in active use at the time of a rollover to a
new MMID version are preserved in the new version. The allocation scheme
requires efficient 64 bit atomics in order to perform reasonably, so
this support depends upon CONFIG_GENERIC_ATOMIC64=n (ie. currently it
will only be included in MIPS64 kernels).

The first, and currently only, available CPU with support for MMIDs is
the MIPS I6500. This CPU supports 16 bit MMIDs, and so for now we cap
our MMIDs to 16 bits wide in order to prevent the bitmap growing to
absurd sizes if any future CPU does implement 32 bit MMIDs as the
architecture manuals suggest is recommended.

When MMIDs are in use we also make use of GINVT instruction which is
available due to the global nature of MMIDs. By executing a sequence of
GINVT &amp; SYNC 0x14 instructions we can avoid the overhead of an IPI to
each remote CPU in many cases. One complication is that GINVT will
invalidate wired entries (in all cases apart from type 0, which targets
the entire TLB). In order to avoid GINVT invalidating any wired TLB
entries we set up, we make sure to create those entries using a reserved
MMID (0) that we never associate with any address space.

Also of note is that KVM will require further work in order to support
MMIDs &amp; GINVT, since KVM is involved in allocating IDs for guests &amp; in
configuring the MMU. That work is not part of this patch, so for now
when MMIDs are in use KVM is disabled.

Signed-off-by: Paul Burton &lt;paul.burton@mips.com&gt;
Cc: linux-mips@vger.kernel.org
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Introduce support for using MemoryMapIDs (MMIDs) as an alternative to
Address Space IDs (ASIDs). The major difference between the two is that
MMIDs are global - ie. an MMID uniquely identifies an address space
across all coherent CPUs. In contrast ASIDs are non-global per-CPU IDs,
wherein each address space is allocated a separate ASID for each CPU
upon which it is used. This global namespace allows a new GINVT
instruction be used to globally invalidate TLB entries associated with a
particular MMID across all coherent CPUs in the system, removing the
need for IPIs to invalidate entries with separate ASIDs on each CPU.

The allocation scheme used here is largely borrowed from arm64 (see
arch/arm64/mm/context.c). In essence we maintain a bitmap to track
available MMIDs, and MMIDs in active use at the time of a rollover to a
new MMID version are preserved in the new version. The allocation scheme
requires efficient 64 bit atomics in order to perform reasonably, so
this support depends upon CONFIG_GENERIC_ATOMIC64=n (ie. currently it
will only be included in MIPS64 kernels).

The first, and currently only, available CPU with support for MMIDs is
the MIPS I6500. This CPU supports 16 bit MMIDs, and so for now we cap
our MMIDs to 16 bits wide in order to prevent the bitmap growing to
absurd sizes if any future CPU does implement 32 bit MMIDs as the
architecture manuals suggest is recommended.

When MMIDs are in use we also make use of GINVT instruction which is
available due to the global nature of MMIDs. By executing a sequence of
GINVT &amp; SYNC 0x14 instructions we can avoid the overhead of an IPI to
each remote CPU in many cases. One complication is that GINVT will
invalidate wired entries (in all cases apart from type 0, which targets
the entire TLB). In order to avoid GINVT invalidating any wired TLB
entries we set up, we make sure to create those entries using a reserved
MMID (0) that we never associate with any address space.

Also of note is that KVM will require further work in order to support
MMIDs &amp; GINVT, since KVM is involved in allocating IDs for guests &amp; in
configuring the MMU. That work is not part of this patch, so for now
when MMIDs are in use KVM is disabled.

Signed-off-by: Paul Burton &lt;paul.burton@mips.com&gt;
Cc: linux-mips@vger.kernel.org
</pre>
</div>
</content>
</entry>
</feed>
