<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/arch/powerpc/Makefile, branch v6.9</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>Merge tag 'powerpc-6.9-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux</title>
<updated>2024-03-16T00:53:48+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2024-03-16T00:53:48+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=66a27abac311a30edbbb65fe8c41ff1b13876faa'/>
<id>66a27abac311a30edbbb65fe8c41ff1b13876faa</id>
<content type='text'>
Pull powerpc updates from Michael Ellerman:

 - Add AT_HWCAP3 and AT_HWCAP4 aux vector entries for future use
   by glibc

 - Add support for recognising the Power11 architected and raw PVRs

 - Add support for nr_cpus=n on the command line where the
   boot CPU is &gt;= n

 - Add ppcxx_allmodconfig targets for all 32-bit sub-arches

 - Other small features, cleanups and fixes

Thanks to Akanksha J N, Brian King, Christophe Leroy, Dawei Li, Geoff
Levand, Greg Kroah-Hartman, Jan-Benedict Glaw, Kajol Jain, Kunwu Chan,
Li zeming, Madhavan Srinivasan, Masahiro Yamada, Nathan Chancellor,
Nicholas Piggin, Peter Bergner, Qiheng Lin, Randy Dunlap, Ricardo B.
Marliere, Rob Herring, Sathvika Vasireddy, Shrikanth Hegde, Uwe
Kleine-König, Vaibhav Jain, and Wen Xiong.

* tag 'powerpc-6.9-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (71 commits)
  powerpc/macio: Make remove callback of macio driver void returned
  powerpc/83xx: Fix build failure with FPU=n
  powerpc/64s: Fix get_hugepd_cache_index() build failure
  powerpc/4xx: Fix warp_gpio_leds build failure
  powerpc/amigaone: Make several functions static
  powerpc/embedded6xx: Fix no previous prototype for avr_uart_send() etc.
  macintosh/adb: make adb_dev_class constant
  powerpc: xor_vmx: Add '-mhard-float' to CFLAGS
  powerpc/fsl: Fix mfpmr() asm constraint error
  powerpc: Remove cpu-as-y completely
  powerpc/fsl: Modernise mt/mfpmr
  powerpc/fsl: Fix mfpmr build errors with newer binutils
  powerpc/64s: Use .machine power4 around dcbt
  powerpc/64s: Move dcbt/dcbtst sequence into a macro
  powerpc/mm: Code cleanup for __hash_page_thp
  powerpc/hv-gpci: Fix the H_GET_PERF_COUNTER_INFO hcall return value checks
  powerpc/irq: Allow softirq to hardirq stack transition
  powerpc: Stop using of_root
  powerpc/machdep: Define 'compatibles' property in ppc_md and use it
  of: Reimplement of_machine_is_compatible() using of_machine_compatible_match()
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull powerpc updates from Michael Ellerman:

 - Add AT_HWCAP3 and AT_HWCAP4 aux vector entries for future use
   by glibc

 - Add support for recognising the Power11 architected and raw PVRs

 - Add support for nr_cpus=n on the command line where the
   boot CPU is &gt;= n

 - Add ppcxx_allmodconfig targets for all 32-bit sub-arches

 - Other small features, cleanups and fixes

Thanks to Akanksha J N, Brian King, Christophe Leroy, Dawei Li, Geoff
Levand, Greg Kroah-Hartman, Jan-Benedict Glaw, Kajol Jain, Kunwu Chan,
Li zeming, Madhavan Srinivasan, Masahiro Yamada, Nathan Chancellor,
Nicholas Piggin, Peter Bergner, Qiheng Lin, Randy Dunlap, Ricardo B.
Marliere, Rob Herring, Sathvika Vasireddy, Shrikanth Hegde, Uwe
Kleine-König, Vaibhav Jain, and Wen Xiong.

* tag 'powerpc-6.9-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (71 commits)
  powerpc/macio: Make remove callback of macio driver void returned
  powerpc/83xx: Fix build failure with FPU=n
  powerpc/64s: Fix get_hugepd_cache_index() build failure
  powerpc/4xx: Fix warp_gpio_leds build failure
  powerpc/amigaone: Make several functions static
  powerpc/embedded6xx: Fix no previous prototype for avr_uart_send() etc.
  macintosh/adb: make adb_dev_class constant
  powerpc: xor_vmx: Add '-mhard-float' to CFLAGS
  powerpc/fsl: Fix mfpmr() asm constraint error
  powerpc: Remove cpu-as-y completely
  powerpc/fsl: Modernise mt/mfpmr
  powerpc/fsl: Fix mfpmr build errors with newer binutils
  powerpc/64s: Use .machine power4 around dcbt
  powerpc/64s: Move dcbt/dcbtst sequence into a macro
  powerpc/mm: Code cleanup for __hash_page_thp
  powerpc/hv-gpci: Fix the H_GET_PERF_COUNTER_INFO hcall return value checks
  powerpc/irq: Allow softirq to hardirq stack transition
  powerpc: Stop using of_root
  powerpc/machdep: Define 'compatibles' property in ppc_md and use it
  of: Reimplement of_machine_is_compatible() using of_machine_compatible_match()
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc: Remove cpu-as-y completely</title>
<updated>2024-03-03T12:05:21+00:00</updated>
<author>
<name>Christophe Leroy</name>
<email>christophe.leroy@csgroup.eu</email>
</author>
<published>2024-02-29T12:25:21+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=ca3d3aa14e7673f1b15e862b71998a4664d50ebe'/>
<id>ca3d3aa14e7673f1b15e862b71998a4664d50ebe</id>
<content type='text'>
cpu-as-y is there to force assembler building options. But there is no
need for that. GCC is passed the necessary options and it automatically
pass the appropriate option to GAS.

GCC is given -maltivec when relevant, so no need for -Wa,-maltivec
either.

And -Wa,-many is wrong as it will hide innapropriate instructions.
Better to detect them and handle them on a case by case basis.

The setting of -Wa,-many was added by commit 960e30029863
("powerpc/Makefile: Fix PPC_BOOK3S_64 ASFLAGS") in order to fix an issue
with clang and the passed -Wa,-mpower4 option. But we have now removed
it expecting the compiler to automatically pass the proper options and
instructions based on -mcpu=power4.

Signed-off-by: Christophe Leroy &lt;christophe.leroy@csgroup.eu&gt;
Acked-by: Segher Boessenkool &lt;segher@kernel.crashing.org&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://msgid.link/20240229122521.762431-5-mpe@ellerman.id.au

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
cpu-as-y is there to force assembler building options. But there is no
need for that. GCC is passed the necessary options and it automatically
pass the appropriate option to GAS.

GCC is given -maltivec when relevant, so no need for -Wa,-maltivec
either.

And -Wa,-many is wrong as it will hide innapropriate instructions.
Better to detect them and handle them on a case by case basis.

The setting of -Wa,-many was added by commit 960e30029863
("powerpc/Makefile: Fix PPC_BOOK3S_64 ASFLAGS") in order to fix an issue
with clang and the passed -Wa,-mpower4 option. But we have now removed
it expecting the compiler to automatically pass the proper options and
instructions based on -mcpu=power4.

Signed-off-by: Christophe Leroy &lt;christophe.leroy@csgroup.eu&gt;
Acked-by: Segher Boessenkool &lt;segher@kernel.crashing.org&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://msgid.link/20240229122521.762431-5-mpe@ellerman.id.au

</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc: Add allmodconfig for all 32-bit sub-arches</title>
<updated>2024-03-03T11:20:29+00:00</updated>
<author>
<name>Michael Ellerman</name>
<email>mpe@ellerman.id.au</email>
</author>
<published>2024-02-29T11:41:08+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=af1ebca503f4c5bb9345dd251faaa825431ce972'/>
<id>af1ebca503f4c5bb9345dd251faaa825431ce972</id>
<content type='text'>
32-bit powerpc kernels can be built for one of 5 sub-arches, see
Kconfig.cputype:

  PPC_BOOK3S_32: "512x/52xx/6xx/7xx/74xx/82xx/83xx/86xx"
  PPC_85xx: "Freescale 85xx"
  PPC_8xx: "Freescale 8xx"
  40x: "AMCC 40x"
  44x: "AMCC 44x, 46x or 47x"

By default none of these are built for a plain allmodconfig build,
because it selects PPC64 which builds a 64-bit kernel.

There is already a ppc32_allmodconfig, which enables PPC_BOOK3S_32.

Add similar targets for the other 32-bit sub-arches to increase build
coverage:
  ppc40x_allmodconfig
  ppc44x_allmodconfig
  ppc8xx_allmodconfig
  ppc85xx_allmodconfig

Acked-by: Uwe Kleine-König &lt;u.kleine-koenig@pengutronix.de&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://msgid.link/20240229114108.743810-1-mpe@ellerman.id.au

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
32-bit powerpc kernels can be built for one of 5 sub-arches, see
Kconfig.cputype:

  PPC_BOOK3S_32: "512x/52xx/6xx/7xx/74xx/82xx/83xx/86xx"
  PPC_85xx: "Freescale 85xx"
  PPC_8xx: "Freescale 8xx"
  40x: "AMCC 40x"
  44x: "AMCC 44x, 46x or 47x"

By default none of these are built for a plain allmodconfig build,
because it selects PPC64 which builds a 64-bit kernel.

There is already a ppc32_allmodconfig, which enables PPC_BOOK3S_32.

Add similar targets for the other 32-bit sub-arches to increase build
coverage:
  ppc40x_allmodconfig
  ppc44x_allmodconfig
  ppc8xx_allmodconfig
  ppc85xx_allmodconfig

Acked-by: Uwe Kleine-König &lt;u.kleine-koenig@pengutronix.de&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://msgid.link/20240229114108.743810-1-mpe@ellerman.id.au

</pre>
</div>
</content>
</entry>
<entry>
<title>treewide: update LLVM Bugzilla links</title>
<updated>2024-02-22T23:38:51+00:00</updated>
<author>
<name>Nathan Chancellor</name>
<email>nathan@kernel.org</email>
</author>
<published>2024-01-09T22:16:31+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=2947a4567f3a79127d2d540384e7f042106c1a24'/>
<id>2947a4567f3a79127d2d540384e7f042106c1a24</id>
<content type='text'>
LLVM moved their issue tracker from their own Bugzilla instance to GitHub
issues.  While all of the links are still valid, they may not necessarily
show the most up to date information around the issues, as all updates
will occur on GitHub, not Bugzilla.

Another complication is that the Bugzilla issue number is not always the
same as the GitHub issue number.  Thankfully, LLVM maintains this mapping
through two shortlinks:

  https://llvm.org/bz&lt;num&gt; -&gt; https://bugs.llvm.org/show_bug.cgi?id=&lt;num&gt;
  https://llvm.org/pr&lt;num&gt; -&gt; https://github.com/llvm/llvm-project/issues/&lt;mapped_num&gt;

Switch all "https://bugs.llvm.org/show_bug.cgi?id=&lt;num&gt;" links to the
"https://llvm.org/pr&lt;num&gt;" shortlink so that the links show the most up to
date information.  Each migrated issue links back to the Bugzilla entry,
so there should be no loss of fidelity of information here.

Link: https://lkml.kernel.org/r/20240109-update-llvm-links-v1-3-eb09b59db071@kernel.org
Signed-off-by: Nathan Chancellor &lt;nathan@kernel.org&gt;
Reviewed-by: Kees Cook &lt;keescook@chromium.org&gt;
Acked-by: Fangrui Song &lt;maskray@google.com&gt;
Cc: Alexei Starovoitov &lt;ast@kernel.org&gt;
Cc: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Cc: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Cc: Mykola Lysenko &lt;mykolal@fb.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
LLVM moved their issue tracker from their own Bugzilla instance to GitHub
issues.  While all of the links are still valid, they may not necessarily
show the most up to date information around the issues, as all updates
will occur on GitHub, not Bugzilla.

Another complication is that the Bugzilla issue number is not always the
same as the GitHub issue number.  Thankfully, LLVM maintains this mapping
through two shortlinks:

  https://llvm.org/bz&lt;num&gt; -&gt; https://bugs.llvm.org/show_bug.cgi?id=&lt;num&gt;
  https://llvm.org/pr&lt;num&gt; -&gt; https://github.com/llvm/llvm-project/issues/&lt;mapped_num&gt;

Switch all "https://bugs.llvm.org/show_bug.cgi?id=&lt;num&gt;" links to the
"https://llvm.org/pr&lt;num&gt;" shortlink so that the links show the most up to
date information.  Each migrated issue links back to the Bugzilla entry,
so there should be no loss of fidelity of information here.

Link: https://lkml.kernel.org/r/20240109-update-llvm-links-v1-3-eb09b59db071@kernel.org
Signed-off-by: Nathan Chancellor &lt;nathan@kernel.org&gt;
Reviewed-by: Kees Cook &lt;keescook@chromium.org&gt;
Acked-by: Fangrui Song &lt;maskray@google.com&gt;
Cc: Alexei Starovoitov &lt;ast@kernel.org&gt;
Cc: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Cc: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Cc: Mykola Lysenko &lt;mykolal@fb.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc/Makefile: Auto detect cross compiler</title>
<updated>2023-12-07T12:34:38+00:00</updated>
<author>
<name>Michael Ellerman</name>
<email>mpe@ellerman.id.au</email>
</author>
<published>2023-12-06T11:55:48+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=402928b58ec62b42b11992a7b51ff2f56ed65a18'/>
<id>402928b58ec62b42b11992a7b51ff2f56ed65a18</id>
<content type='text'>
If no cross compiler is specified, try to auto detect one.

Look for various combinations, matching:
  powerpc(64(le)?)?(-unknown)?-linux(-gnu)?-

There are more possibilities, but the above is known to find a compiler
on Fedora and Ubuntu (which use linux-gnu-), and also detects the
kernel.org cross compilers (which use linux-).

This allows cross compiling with simply:

 # Ubuntu
 $ sudo apt install gcc-powerpc-linux-gnu
 # Fedora
 $ sudo dnf install gcc-powerpc64-linux-gnu

 $ make ARCH=powerpc defconfig
 $ make ARCH=powerpc -j 4

Inspired by arch/parisc/Makefile.

Acked-by: Segher Boessenkool &lt;segher@kernel.crashing.org&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://msgid.link/20231206115548.1466874-4-mpe@ellerman.id.au

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
If no cross compiler is specified, try to auto detect one.

Look for various combinations, matching:
  powerpc(64(le)?)?(-unknown)?-linux(-gnu)?-

There are more possibilities, but the above is known to find a compiler
on Fedora and Ubuntu (which use linux-gnu-), and also detects the
kernel.org cross compilers (which use linux-).

This allows cross compiling with simply:

 # Ubuntu
 $ sudo apt install gcc-powerpc-linux-gnu
 # Fedora
 $ sudo dnf install gcc-powerpc64-linux-gnu

 $ make ARCH=powerpc defconfig
 $ make ARCH=powerpc -j 4

Inspired by arch/parisc/Makefile.

Acked-by: Segher Boessenkool &lt;segher@kernel.crashing.org&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://msgid.link/20231206115548.1466874-4-mpe@ellerman.id.au

</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc/Makefile: Default to ppc64le_defconfig when cross building</title>
<updated>2023-12-07T12:34:38+00:00</updated>
<author>
<name>Michael Ellerman</name>
<email>mpe@ellerman.id.au</email>
</author>
<published>2023-12-06T11:55:47+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=22f17b02f88b48c01d3ac38d40d2b0b695ab2d10'/>
<id>22f17b02f88b48c01d3ac38d40d2b0b695ab2d10</id>
<content type='text'>
If the kernel is being cross compiled, there is no information from
uname on which defconfig is most appropriate, so the Makefile defaults
to ppc64.

However these days almost all distros that support powerpc are little
endian, so it's more likely that defaulting to ppc64le_defconfig will
produce something useful for a user.

Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://msgid.link/20231206115548.1466874-3-mpe@ellerman.id.au

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
If the kernel is being cross compiled, there is no information from
uname on which defconfig is most appropriate, so the Makefile defaults
to ppc64.

However these days almost all distros that support powerpc are little
endian, so it's more likely that defaulting to ppc64le_defconfig will
produce something useful for a user.

Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://msgid.link/20231206115548.1466874-3-mpe@ellerman.id.au

</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc/Makefile: Don't use $(ARCH) unnecessarily</title>
<updated>2023-12-07T12:34:38+00:00</updated>
<author>
<name>Michael Ellerman</name>
<email>mpe@ellerman.id.au</email>
</author>
<published>2023-12-06T11:55:45+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=dc420877b5bd92db5d80df6b117c7a0f987290af'/>
<id>dc420877b5bd92db5d80df6b117c7a0f987290af</id>
<content type='text'>
There's no need to use $(ARCH) for references to the arch directory in
the source tree, it is always arch/powerpc.

Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://msgid.link/20231206115548.1466874-1-mpe@ellerman.id.au

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
There's no need to use $(ARCH) for references to the arch directory in
the source tree, it is always arch/powerpc.

Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://msgid.link/20231206115548.1466874-1-mpe@ellerman.id.au

</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc/64s: Move CPU -mtune options into Kconfig</title>
<updated>2023-08-24T22:39:29+00:00</updated>
<author>
<name>Michael Ellerman</name>
<email>mpe@ellerman.id.au</email>
</author>
<published>2023-03-29T23:43:08+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=50832720ec54c39ab189cd5e057aec1c514978ce'/>
<id>50832720ec54c39ab189cd5e057aec1c514978ce</id>
<content type='text'>
Currently the -mtune options are set in the Makefile, depending on what
the compiler supports.

One downside of doing it that way is that the chosen -mtune option is
not recorded in the .config.

Another downside is that if there's ever a need to do more complicated
logic to calculate the correct option, that gets messy in the Makefile.

So move the determination of which -mtune option to use into Kconfig
logic.

Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://msgid.link/20230329234308.2215833-1-mpe@ellerman.id.au

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Currently the -mtune options are set in the Makefile, depending on what
the compiler supports.

One downside of doing it that way is that the chosen -mtune option is
not recorded in the .config.

Another downside is that if there's ever a need to do more complicated
logic to calculate the correct option, that gets messy in the Makefile.

So move the determination of which -mtune option to use into Kconfig
logic.

Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://msgid.link/20230329234308.2215833-1-mpe@ellerman.id.au

</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc/ftrace: Add support for -fpatchable-function-entry</title>
<updated>2023-08-21T14:09:06+00:00</updated>
<author>
<name>Naveen N Rao</name>
<email>naveen@kernel.org</email>
</author>
<published>2023-06-19T09:47:34+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=0f71dcfb4aef6043da6cc509e7a7f6a3ae87c12d'/>
<id>0f71dcfb4aef6043da6cc509e7a7f6a3ae87c12d</id>
<content type='text'>
GCC v13.1 updated support for -fpatchable-function-entry on ppc64le to
emit nops after the local entry point, rather than before it. This
allows us to use this in the kernel for ftrace purposes. A new script is
added under arch/powerpc/tools/ to help detect if nops are emitted after
the function local entry point, or before the global entry point.

With -fpatchable-function-entry, we no longer have the profiling
instructions generated at function entry, so we only need to validate
the presence of two nops at the ftrace location in ftrace_init_nop(). We
patch the preceding instruction with 'mflr r0' to match the
-mprofile-kernel ABI for subsequent ftrace use.

This changes the profiling instructions used on ppc32. The default -pg
option emits an additional 'stw' instruction after 'mflr r0' and before
the branch to _mcount 'bl _mcount'. This is very similar to the original
-mprofile-kernel implementation on ppc64le, where an additional 'std'
instruction was used to save LR to its save location in the caller's
stackframe. Subsequently, this additional store was removed in later
compiler versions for performance reasons. The same reasons apply for
ppc32 so we only patch in a 'mflr r0'.

Signed-off-by: Naveen N Rao &lt;naveen@kernel.org&gt;
Reviewed-by: Christophe Leroy &lt;christophe.leroy@csgroup.eu&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://msgid.link/68586d22981a2c3bb45f27a2b621173d10a7d092.1687166935.git.naveen@kernel.org

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
GCC v13.1 updated support for -fpatchable-function-entry on ppc64le to
emit nops after the local entry point, rather than before it. This
allows us to use this in the kernel for ftrace purposes. A new script is
added under arch/powerpc/tools/ to help detect if nops are emitted after
the function local entry point, or before the global entry point.

With -fpatchable-function-entry, we no longer have the profiling
instructions generated at function entry, so we only need to validate
the presence of two nops at the ftrace location in ftrace_init_nop(). We
patch the preceding instruction with 'mflr r0' to match the
-mprofile-kernel ABI for subsequent ftrace use.

This changes the profiling instructions used on ppc32. The default -pg
option emits an additional 'stw' instruction after 'mflr r0' and before
the branch to _mcount 'bl _mcount'. This is very similar to the original
-mprofile-kernel implementation on ppc64le, where an additional 'std'
instruction was used to save LR to its save location in the caller's
stackframe. Subsequently, this additional store was removed in later
compiler versions for performance reasons. The same reasons apply for
ppc32 so we only patch in a 'mflr r0'.

Signed-off-by: Naveen N Rao &lt;naveen@kernel.org&gt;
Reviewed-by: Christophe Leroy &lt;christophe.leroy@csgroup.eu&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://msgid.link/68586d22981a2c3bb45f27a2b621173d10a7d092.1687166935.git.naveen@kernel.org

</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc: remove checks for binutils older than 2.25</title>
<updated>2023-06-27T06:59:29+00:00</updated>
<author>
<name>Masahiro Yamada</name>
<email>masahiroy@kernel.org</email>
</author>
<published>2023-01-19T08:22:50+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=54a11654de163994e32b24e3aa90ef81f4a3184d'/>
<id>54a11654de163994e32b24e3aa90ef81f4a3184d</id>
<content type='text'>
Commit e4412739472b ("Documentation: raise minimum supported version of
binutils to 2.25") allows us to remove the checks for old binutils.

There is no more user for ld-ifversion. Remove it as well.

Signed-off-by: Masahiro Yamada &lt;masahiroy@kernel.org&gt;
Reviewed-by: Nicholas Piggin &lt;npiggin@gmail.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://msgid.link/20230119082250.151485-1-masahiroy@kernel.org
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Commit e4412739472b ("Documentation: raise minimum supported version of
binutils to 2.25") allows us to remove the checks for old binutils.

There is no more user for ld-ifversion. Remove it as well.

Signed-off-by: Masahiro Yamada &lt;masahiroy@kernel.org&gt;
Reviewed-by: Nicholas Piggin &lt;npiggin@gmail.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://msgid.link/20230119082250.151485-1-masahiroy@kernel.org
</pre>
</div>
</content>
</entry>
</feed>
