<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/arch/powerpc/kernel/Makefile, branch v5.18</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/vdso: Merge vdso64 and vdso32 into a single directory</title>
<updated>2022-02-12T11:47:43+00:00</updated>
<author>
<name>Christophe Leroy</name>
<email>christophe.leroy@csgroup.eu</email>
</author>
<published>2022-01-21T16:30:27+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=fd1feade75fb1a9275c39d76c5ccdbbbe6b37aa3'/>
<id>fd1feade75fb1a9275c39d76c5ccdbbbe6b37aa3</id>
<content type='text'>
merge vdso64 into vdso32 and rename it vdso.

Reported-by: kernel test robot &lt;lkp@intel.com&gt;
Signed-off-by: Christophe Leroy &lt;christophe.leroy@csgroup.eu&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/4dbe05cc130f6a0858d09ac72e436c373cb08b70.1642782130.git.christophe.leroy@csgroup.eu

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
merge vdso64 into vdso32 and rename it vdso.

Reported-by: kernel test robot &lt;lkp@intel.com&gt;
Signed-off-by: Christophe Leroy &lt;christophe.leroy@csgroup.eu&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/4dbe05cc130f6a0858d09ac72e436c373cb08b70.1642782130.git.christophe.leroy@csgroup.eu

</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'powerpc-5.17-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux</title>
<updated>2022-01-14T14:17:26+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2022-01-14T14:17:26+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=29ec39fcf11e4583eb8d5174f756ea109c77cc44'/>
<id>29ec39fcf11e4583eb8d5174f756ea109c77cc44</id>
<content type='text'>
Pull powerpc updates from Michael Ellerman:

 - Optimise radix KVM guest entry/exit by 2x on Power9/Power10.

 - Allow firmware to tell us whether to disable the entry and uaccess
   flushes on Power10 or later CPUs.

 - Add BPF_PROBE_MEM support for 32 and 64-bit BPF jits.

 - Several fixes and improvements to our hard lockup watchdog.

 - Activate HAVE_DYNAMIC_FTRACE_WITH_REGS on 32-bit.

 - Allow building the 64-bit Book3S kernel without hash MMU support, ie.
   Radix only.

 - Add KUAP (SMAP) support for 40x, 44x, 8xx, Book3E (64-bit).

 - Add new encodings for perf_mem_data_src.mem_hops field, and use them
   on Power10.

 - A series of small performance improvements to 64-bit interrupt entry.

 - Several commits fixing issues when building with the clang integrated
   assembler.

 - Many other small features and fixes.

Thanks to Alan Modra, Alexey Kardashevskiy, Ammar Faizi, Anders Roxell,
Arnd Bergmann, Athira Rajeev, Cédric Le Goater, Christophe JAILLET,
Christophe Leroy, Christoph Hellwig, Daniel Axtens, David Yang, Erhard
Furtner, Fabiano Rosas, Greg Kroah-Hartman, Guo Ren, Hari Bathini, Jason
Wang, Joel Stanley, Julia Lawall, Kajol Jain, Kees Cook, Laurent Dufour,
Madhavan Srinivasan, Mark Brown, Minghao Chi, Nageswara R Sastry, Naresh
Kamboju, Nathan Chancellor, Nathan Lynch, Nicholas Piggin, Nick Child,
Oliver O'Halloran, Peiwei Hu, Randy Dunlap, Ravi Bangoria, Rob Herring,
Russell Currey, Sachin Sant, Sean Christopherson, Segher Boessenkool,
Thadeu Lima de Souza Cascardo, Tyrel Datwyler, Xiang wangx, and Yang
Guang.

* tag 'powerpc-5.17-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (240 commits)
  powerpc/xmon: Dump XIVE information for online-only processors.
  powerpc/opal: use default_groups in kobj_type
  powerpc/cacheinfo: use default_groups in kobj_type
  powerpc/sched: Remove unused TASK_SIZE_OF
  powerpc/xive: Add missing null check after calling kmalloc
  powerpc/floppy: Remove usage of the deprecated "pci-dma-compat.h" API
  selftests/powerpc: Add a test of sigreturning to an unaligned address
  powerpc/64s: Use EMIT_WARN_ENTRY for SRR debug warnings
  powerpc/64s: Mask NIP before checking against SRR0
  powerpc/perf: Fix spelling of "its"
  powerpc/32: Fix boot failure with GCC latent entropy plugin
  powerpc/code-patching: Replace patch_instruction() by ppc_inst_write() in selftests
  powerpc/code-patching: Move code patching selftests in its own file
  powerpc/code-patching: Move instr_is_branch_{i/b}form() in code-patching.h
  powerpc/code-patching: Move patch_exception() outside code-patching.c
  powerpc/code-patching: Use test_trampoline for prefixed patch test
  powerpc/code-patching: Fix patch_branch() return on out-of-range failure
  powerpc/code-patching: Reorganise do_patch_instruction() to ease error handling
  powerpc/code-patching: Fix unmap_patch_area() error handling
  powerpc/code-patching: Fix error handling in do_patch_instruction()
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull powerpc updates from Michael Ellerman:

 - Optimise radix KVM guest entry/exit by 2x on Power9/Power10.

 - Allow firmware to tell us whether to disable the entry and uaccess
   flushes on Power10 or later CPUs.

 - Add BPF_PROBE_MEM support for 32 and 64-bit BPF jits.

 - Several fixes and improvements to our hard lockup watchdog.

 - Activate HAVE_DYNAMIC_FTRACE_WITH_REGS on 32-bit.

 - Allow building the 64-bit Book3S kernel without hash MMU support, ie.
   Radix only.

 - Add KUAP (SMAP) support for 40x, 44x, 8xx, Book3E (64-bit).

 - Add new encodings for perf_mem_data_src.mem_hops field, and use them
   on Power10.

 - A series of small performance improvements to 64-bit interrupt entry.

 - Several commits fixing issues when building with the clang integrated
   assembler.

 - Many other small features and fixes.

Thanks to Alan Modra, Alexey Kardashevskiy, Ammar Faizi, Anders Roxell,
Arnd Bergmann, Athira Rajeev, Cédric Le Goater, Christophe JAILLET,
Christophe Leroy, Christoph Hellwig, Daniel Axtens, David Yang, Erhard
Furtner, Fabiano Rosas, Greg Kroah-Hartman, Guo Ren, Hari Bathini, Jason
Wang, Joel Stanley, Julia Lawall, Kajol Jain, Kees Cook, Laurent Dufour,
Madhavan Srinivasan, Mark Brown, Minghao Chi, Nageswara R Sastry, Naresh
Kamboju, Nathan Chancellor, Nathan Lynch, Nicholas Piggin, Nick Child,
Oliver O'Halloran, Peiwei Hu, Randy Dunlap, Ravi Bangoria, Rob Herring,
Russell Currey, Sachin Sant, Sean Christopherson, Segher Boessenkool,
Thadeu Lima de Souza Cascardo, Tyrel Datwyler, Xiang wangx, and Yang
Guang.

* tag 'powerpc-5.17-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (240 commits)
  powerpc/xmon: Dump XIVE information for online-only processors.
  powerpc/opal: use default_groups in kobj_type
  powerpc/cacheinfo: use default_groups in kobj_type
  powerpc/sched: Remove unused TASK_SIZE_OF
  powerpc/xive: Add missing null check after calling kmalloc
  powerpc/floppy: Remove usage of the deprecated "pci-dma-compat.h" API
  selftests/powerpc: Add a test of sigreturning to an unaligned address
  powerpc/64s: Use EMIT_WARN_ENTRY for SRR debug warnings
  powerpc/64s: Mask NIP before checking against SRR0
  powerpc/perf: Fix spelling of "its"
  powerpc/32: Fix boot failure with GCC latent entropy plugin
  powerpc/code-patching: Replace patch_instruction() by ppc_inst_write() in selftests
  powerpc/code-patching: Move code patching selftests in its own file
  powerpc/code-patching: Move instr_is_branch_{i/b}form() in code-patching.h
  powerpc/code-patching: Move patch_exception() outside code-patching.c
  powerpc/code-patching: Use test_trampoline for prefixed patch test
  powerpc/code-patching: Fix patch_branch() return on out-of-range failure
  powerpc/code-patching: Reorganise do_patch_instruction() to ease error handling
  powerpc/code-patching: Fix unmap_patch_area() error handling
  powerpc/code-patching: Fix error handling in do_patch_instruction()
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc/32: Fix boot failure with GCC latent entropy plugin</title>
<updated>2021-12-23T11:36:58+00:00</updated>
<author>
<name>Christophe Leroy</name>
<email>christophe.leroy@csgroup.eu</email>
</author>
<published>2021-12-22T13:07:31+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=bba496656a73fc1d1330b49c7f82843836e9feb1'/>
<id>bba496656a73fc1d1330b49c7f82843836e9feb1</id>
<content type='text'>
Boot fails with GCC latent entropy plugin enabled.

This is due to early boot functions trying to access 'latent_entropy'
global data while the kernel is not relocated at its final
destination yet.

As there is no way to tell GCC to use PTRRELOC() to access it,
disable latent entropy plugin in early_32.o and feature-fixups.o and
code-patching.o

Fixes: 38addce8b600 ("gcc-plugins: Add latent_entropy plugin")
Cc: stable@vger.kernel.org # v4.9+
Reported-by: Erhard Furtner &lt;erhard_f@mailbox.org&gt;
Signed-off-by: Christophe Leroy &lt;christophe.leroy@csgroup.eu&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://bugzilla.kernel.org/show_bug.cgi?id=215217
Link: https://lore.kernel.org/r/2bac55483b8daf5b1caa163a45fa5f9cdbe18be4.1640178426.git.christophe.leroy@csgroup.eu

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Boot fails with GCC latent entropy plugin enabled.

This is due to early boot functions trying to access 'latent_entropy'
global data while the kernel is not relocated at its final
destination yet.

As there is no way to tell GCC to use PTRRELOC() to access it,
disable latent entropy plugin in early_32.o and feature-fixups.o and
code-patching.o

Fixes: 38addce8b600 ("gcc-plugins: Add latent_entropy plugin")
Cc: stable@vger.kernel.org # v4.9+
Reported-by: Erhard Furtner &lt;erhard_f@mailbox.org&gt;
Signed-off-by: Christophe Leroy &lt;christophe.leroy@csgroup.eu&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://bugzilla.kernel.org/show_bug.cgi?id=215217
Link: https://lore.kernel.org/r/2bac55483b8daf5b1caa163a45fa5f9cdbe18be4.1640178426.git.christophe.leroy@csgroup.eu

</pre>
</div>
</content>
</entry>
<entry>
<title>arch: Make ARCH_STACKWALK independent of STACKTRACE</title>
<updated>2021-12-10T14:06:03+00:00</updated>
<author>
<name>Peter Zijlstra</name>
<email>peterz@infradead.org</email>
</author>
<published>2021-11-29T14:28:41+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=1614b2b11fab29dd4ff31ebba9d266961f5af69e'/>
<id>1614b2b11fab29dd4ff31ebba9d266961f5af69e</id>
<content type='text'>
Make arch_stack_walk() available for ARCH_STACKWALK architectures
without it being entangled in STACKTRACE.

Link: https://lore.kernel.org/lkml/20211022152104.356586621@infradead.org/
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
[Mark: rebase, drop unnecessary arm change]
Signed-off-by: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Albert Ou &lt;aou@eecs.berkeley.edu&gt;
Cc: Borislav Petkov &lt;bp@alien8.de&gt;
Cc: Christian Borntraeger &lt;borntraeger@de.ibm.com&gt;
Cc: Dave Hansen &lt;dave.hansen@linux.intel.com&gt;
Cc: Heiko Carstens &lt;hca@linux.ibm.com&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Cc: Palmer Dabbelt &lt;palmer@dabbelt.com&gt;
Cc: Paul Walmsley &lt;paul.walmsley@sifive.com&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Vasily Gorbik &lt;gor@linux.ibm.com&gt;
Link: https://lore.kernel.org/r/20211129142849.3056714-2-mark.rutland@arm.com
Signed-off-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Make arch_stack_walk() available for ARCH_STACKWALK architectures
without it being entangled in STACKTRACE.

Link: https://lore.kernel.org/lkml/20211022152104.356586621@infradead.org/
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
[Mark: rebase, drop unnecessary arm change]
Signed-off-by: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Albert Ou &lt;aou@eecs.berkeley.edu&gt;
Cc: Borislav Petkov &lt;bp@alien8.de&gt;
Cc: Christian Borntraeger &lt;borntraeger@de.ibm.com&gt;
Cc: Dave Hansen &lt;dave.hansen@linux.intel.com&gt;
Cc: Heiko Carstens &lt;hca@linux.ibm.com&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Cc: Palmer Dabbelt &lt;palmer@dabbelt.com&gt;
Cc: Paul Walmsley &lt;paul.walmsley@sifive.com&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Vasily Gorbik &lt;gor@linux.ibm.com&gt;
Link: https://lore.kernel.org/r/20211129142849.3056714-2-mark.rutland@arm.com
Signed-off-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc: clean vdso32 and vdso64 directories</title>
<updated>2021-11-15T04:46:45+00:00</updated>
<author>
<name>Masahiro Yamada</name>
<email>masahiroy@kernel.org</email>
</author>
<published>2021-11-09T18:50:15+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=964c33cd0be621b291b5d253d8731eb2680082cb'/>
<id>964c33cd0be621b291b5d253d8731eb2680082cb</id>
<content type='text'>
Since commit bce74491c300 ("powerpc/vdso: fix unnecessary rebuilds of
vgettimeofday.o"), "make ARCH=powerpc clean" does not clean up the
arch/powerpc/kernel/{vdso32,vdso64} directories.

Use the subdir- trick to let "make clean" descend into them.

Fixes: bce74491c300 ("powerpc/vdso: fix unnecessary rebuilds of vgettimeofday.o")
Signed-off-by: Masahiro Yamada &lt;masahiroy@kernel.org&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20211109185015.615517-1-masahiroy@kernel.org

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Since commit bce74491c300 ("powerpc/vdso: fix unnecessary rebuilds of
vgettimeofday.o"), "make ARCH=powerpc clean" does not clean up the
arch/powerpc/kernel/{vdso32,vdso64} directories.

Use the subdir- trick to let "make clean" descend into them.

Fixes: bce74491c300 ("powerpc/vdso: fix unnecessary rebuilds of vgettimeofday.o")
Signed-off-by: Masahiro Yamada &lt;masahiroy@kernel.org&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20211109185015.615517-1-masahiroy@kernel.org

</pre>
</div>
</content>
</entry>
<entry>
<title>Revert "powerpc/audit: Convert powerpc to AUDIT_ARCH_COMPAT_GENERIC"</title>
<updated>2021-10-27T11:30:32+00:00</updated>
<author>
<name>Michael Ellerman</name>
<email>mpe@ellerman.id.au</email>
</author>
<published>2021-10-27T11:29:31+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=b7472e1764bfc0fe3d6578cb281e81c812ca5886'/>
<id>b7472e1764bfc0fe3d6578cb281e81c812ca5886</id>
<content type='text'>
This reverts commit 566af8cda399c088763d07464463dc871c943b54.

This caused some conflicts vs the audit tree, and the audit maintainers
would prefer we postpone this to the next merge window so we have more
time for testing.

Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This reverts commit 566af8cda399c088763d07464463dc871c943b54.

This caused some conflicts vs the audit tree, and the audit maintainers
would prefer we postpone this to the next merge window so we have more
time for testing.

Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc/32: Add support for out-of-line static calls</title>
<updated>2021-10-22T04:22:05+00:00</updated>
<author>
<name>Christophe Leroy</name>
<email>christophe.leroy@csgroup.eu</email>
</author>
<published>2021-09-01T08:30:21+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=5c810ced36ae1a8f1a7403c1635b0dc07c115086'/>
<id>5c810ced36ae1a8f1a7403c1635b0dc07c115086</id>
<content type='text'>
Add support for out-of-line static calls on PPC32. This change
improve performance of calls to global function pointers by
using direct calls instead of indirect calls.

The trampoline is initialy populated with a 'blr' or branch to target,
followed by an unreachable long jump sequence.

In order to cater with parallele execution, the trampoline needs to
be updated in a way that ensures it remains consistent at all time.
This means we can't use the traditional lis/addi to load r12 with
the target address, otherwise there would be a window during which
the first instruction contains the upper part of the new target
address while the second instruction still contains the lower part of
the old target address. To avoid that the target address is stored
just after the 'bctr' and loaded from there with a single instruction.

Then, depending on the target distance, arch_static_call_transform()
will either replace the first instruction by a direct 'bl &lt;target&gt;' or
'nop' in order to have the trampoline fall through the long jump
sequence.

For the special case of __static_call_return0(), to avoid the risk of
a far branch, a version of it is inlined at the end of the trampoline.

Performancewise the long jump sequence is probably not better than
the indirect calls set by GCC when we don't use static calls, but
such calls are unlikely to be required on powerpc32: With most
configurations the kernel size is far below 32 Mbytes so only
modules may happen to be too far. And even modules are likely to
be close enough as they are allocated below the kernel core and
as close as possible of the kernel text.

static_call selftest is running successfully with this change.

With this patch, __do_irq() has the following sequence to trace
irq entries:

	c0004a00 &lt;__SCT__tp_func_irq_entry&gt;:
	c0004a00:	48 00 00 e0 	b       c0004ae0 &lt;__traceiter_irq_entry&gt;
	c0004a04:	3d 80 c0 00 	lis     r12,-16384
	c0004a08:	81 8c 4a 1c 	lwz     r12,18972(r12)
	c0004a0c:	7d 89 03 a6 	mtctr   r12
	c0004a10:	4e 80 04 20 	bctr
	c0004a14:	38 60 00 00 	li      r3,0
	c0004a18:	4e 80 00 20 	blr
	c0004a1c:	00 00 00 00 	.long 0x0
...
	c0005654 &lt;__do_irq&gt;:
...
	c0005664:	7c 7f 1b 78 	mr      r31,r3
...
	c00056a0:	81 22 00 00 	lwz     r9,0(r2)
	c00056a4:	39 29 00 01 	addi    r9,r9,1
	c00056a8:	91 22 00 00 	stw     r9,0(r2)
	c00056ac:	3d 20 c0 af 	lis     r9,-16209
	c00056b0:	81 29 74 cc 	lwz     r9,29900(r9)
	c00056b4:	2c 09 00 00 	cmpwi   r9,0
	c00056b8:	41 82 00 10 	beq     c00056c8 &lt;__do_irq+0x74&gt;
	c00056bc:	80 69 00 04 	lwz     r3,4(r9)
	c00056c0:	7f e4 fb 78 	mr      r4,r31
	c00056c4:	4b ff f3 3d 	bl      c0004a00 &lt;__SCT__tp_func_irq_entry&gt;

Before this patch, __do_irq() was doing the following to trace irq
entries:

	c0005700 &lt;__do_irq&gt;:
...
	c0005710:	7c 7e 1b 78 	mr      r30,r3
...
	c000574c:	93 e1 00 0c 	stw     r31,12(r1)
	c0005750:	81 22 00 00 	lwz     r9,0(r2)
	c0005754:	39 29 00 01 	addi    r9,r9,1
	c0005758:	91 22 00 00 	stw     r9,0(r2)
	c000575c:	3d 20 c0 af 	lis     r9,-16209
	c0005760:	83 e9 f4 cc 	lwz     r31,-2868(r9)
	c0005764:	2c 1f 00 00 	cmpwi   r31,0
	c0005768:	41 82 00 24 	beq     c000578c &lt;__do_irq+0x8c&gt;
	c000576c:	81 3f 00 00 	lwz     r9,0(r31)
	c0005770:	80 7f 00 04 	lwz     r3,4(r31)
	c0005774:	7d 29 03 a6 	mtctr   r9
	c0005778:	7f c4 f3 78 	mr      r4,r30
	c000577c:	4e 80 04 21 	bctrl
	c0005780:	85 3f 00 0c 	lwzu    r9,12(r31)
	c0005784:	2c 09 00 00 	cmpwi   r9,0
	c0005788:	40 82 ff e4 	bne     c000576c &lt;__do_irq+0x6c&gt;

Behind the fact of now using a direct 'bl' instead of a
'load/mtctr/bctr' sequence, we can also see that we get one less
register on the stack.

Signed-off-by: Christophe Leroy &lt;christophe.leroy@csgroup.eu&gt;
Acked-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/6ec2a7865ed6a5ec54ab46d026785bafe1d837ea.1630484892.git.christophe.leroy@csgroup.eu

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Add support for out-of-line static calls on PPC32. This change
improve performance of calls to global function pointers by
using direct calls instead of indirect calls.

The trampoline is initialy populated with a 'blr' or branch to target,
followed by an unreachable long jump sequence.

In order to cater with parallele execution, the trampoline needs to
be updated in a way that ensures it remains consistent at all time.
This means we can't use the traditional lis/addi to load r12 with
the target address, otherwise there would be a window during which
the first instruction contains the upper part of the new target
address while the second instruction still contains the lower part of
the old target address. To avoid that the target address is stored
just after the 'bctr' and loaded from there with a single instruction.

Then, depending on the target distance, arch_static_call_transform()
will either replace the first instruction by a direct 'bl &lt;target&gt;' or
'nop' in order to have the trampoline fall through the long jump
sequence.

For the special case of __static_call_return0(), to avoid the risk of
a far branch, a version of it is inlined at the end of the trampoline.

Performancewise the long jump sequence is probably not better than
the indirect calls set by GCC when we don't use static calls, but
such calls are unlikely to be required on powerpc32: With most
configurations the kernel size is far below 32 Mbytes so only
modules may happen to be too far. And even modules are likely to
be close enough as they are allocated below the kernel core and
as close as possible of the kernel text.

static_call selftest is running successfully with this change.

With this patch, __do_irq() has the following sequence to trace
irq entries:

	c0004a00 &lt;__SCT__tp_func_irq_entry&gt;:
	c0004a00:	48 00 00 e0 	b       c0004ae0 &lt;__traceiter_irq_entry&gt;
	c0004a04:	3d 80 c0 00 	lis     r12,-16384
	c0004a08:	81 8c 4a 1c 	lwz     r12,18972(r12)
	c0004a0c:	7d 89 03 a6 	mtctr   r12
	c0004a10:	4e 80 04 20 	bctr
	c0004a14:	38 60 00 00 	li      r3,0
	c0004a18:	4e 80 00 20 	blr
	c0004a1c:	00 00 00 00 	.long 0x0
...
	c0005654 &lt;__do_irq&gt;:
...
	c0005664:	7c 7f 1b 78 	mr      r31,r3
...
	c00056a0:	81 22 00 00 	lwz     r9,0(r2)
	c00056a4:	39 29 00 01 	addi    r9,r9,1
	c00056a8:	91 22 00 00 	stw     r9,0(r2)
	c00056ac:	3d 20 c0 af 	lis     r9,-16209
	c00056b0:	81 29 74 cc 	lwz     r9,29900(r9)
	c00056b4:	2c 09 00 00 	cmpwi   r9,0
	c00056b8:	41 82 00 10 	beq     c00056c8 &lt;__do_irq+0x74&gt;
	c00056bc:	80 69 00 04 	lwz     r3,4(r9)
	c00056c0:	7f e4 fb 78 	mr      r4,r31
	c00056c4:	4b ff f3 3d 	bl      c0004a00 &lt;__SCT__tp_func_irq_entry&gt;

Before this patch, __do_irq() was doing the following to trace irq
entries:

	c0005700 &lt;__do_irq&gt;:
...
	c0005710:	7c 7e 1b 78 	mr      r30,r3
...
	c000574c:	93 e1 00 0c 	stw     r31,12(r1)
	c0005750:	81 22 00 00 	lwz     r9,0(r2)
	c0005754:	39 29 00 01 	addi    r9,r9,1
	c0005758:	91 22 00 00 	stw     r9,0(r2)
	c000575c:	3d 20 c0 af 	lis     r9,-16209
	c0005760:	83 e9 f4 cc 	lwz     r31,-2868(r9)
	c0005764:	2c 1f 00 00 	cmpwi   r31,0
	c0005768:	41 82 00 24 	beq     c000578c &lt;__do_irq+0x8c&gt;
	c000576c:	81 3f 00 00 	lwz     r9,0(r31)
	c0005770:	80 7f 00 04 	lwz     r3,4(r31)
	c0005774:	7d 29 03 a6 	mtctr   r9
	c0005778:	7f c4 f3 78 	mr      r4,r30
	c000577c:	4e 80 04 21 	bctrl
	c0005780:	85 3f 00 0c 	lwzu    r9,12(r31)
	c0005784:	2c 09 00 00 	cmpwi   r9,0
	c0005788:	40 82 ff e4 	bne     c000576c &lt;__do_irq+0x6c&gt;

Behind the fact of now using a direct 'bl' instead of a
'load/mtctr/bctr' sequence, we can also see that we get one less
register on the stack.

Signed-off-by: Christophe Leroy &lt;christophe.leroy@csgroup.eu&gt;
Acked-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/6ec2a7865ed6a5ec54ab46d026785bafe1d837ea.1630484892.git.christophe.leroy@csgroup.eu

</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc/audit: Convert powerpc to AUDIT_ARCH_COMPAT_GENERIC</title>
<updated>2021-10-22T04:22:04+00:00</updated>
<author>
<name>Christophe Leroy</name>
<email>christophe.leroy@csgroup.eu</email>
</author>
<published>2021-08-24T13:36:13+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=566af8cda399c088763d07464463dc871c943b54'/>
<id>566af8cda399c088763d07464463dc871c943b54</id>
<content type='text'>
Commit e65e1fc2d24b ("[PATCH] syscall class hookup for all normal
targets") added generic support for AUDIT but that didn't include
support for bi-arch like powerpc.

Commit 4b58841149dc ("audit: Add generic compat syscall support")
added generic support for bi-arch.

Convert powerpc to that bi-arch generic audit support.

Signed-off-by: Christophe Leroy &lt;christophe.leroy@csgroup.eu&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/a4b3951d1191d4183d92a07a6097566bde60d00a.1629812058.git.christophe.leroy@csgroup.eu

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Commit e65e1fc2d24b ("[PATCH] syscall class hookup for all normal
targets") added generic support for AUDIT but that didn't include
support for bi-arch like powerpc.

Commit 4b58841149dc ("audit: Add generic compat syscall support")
added generic support for bi-arch.

Convert powerpc to that bi-arch generic audit support.

Signed-off-by: Christophe Leroy &lt;christophe.leroy@csgroup.eu&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/a4b3951d1191d4183d92a07a6097566bde60d00a.1629812058.git.christophe.leroy@csgroup.eu

</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc: rename powerpc_debugfs_root to arch_debugfs_dir</title>
<updated>2021-08-13T12:04:26+00:00</updated>
<author>
<name>Aneesh Kumar K.V</name>
<email>aneesh.kumar@linux.ibm.com</email>
</author>
<published>2021-08-12T13:28:31+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=dbf77fed8b302e87561c7c2fc06050c88f4d3120'/>
<id>dbf77fed8b302e87561c7c2fc06050c88f4d3120</id>
<content type='text'>
No functional change in this patch. arch_debugfs_dir is the generic kernel
name declared in linux/debugfs.h for arch-specific debugfs directory.
Architectures like x86/s390 already use the name. Rename powerpc
specific powerpc_debugfs_root to arch_debugfs_dir.

Signed-off-by: Aneesh Kumar K.V &lt;aneesh.kumar@linux.ibm.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20210812132831.233794-2-aneesh.kumar@linux.ibm.com

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
No functional change in this patch. arch_debugfs_dir is the generic kernel
name declared in linux/debugfs.h for arch-specific debugfs directory.
Architectures like x86/s390 already use the name. Rename powerpc
specific powerpc_debugfs_root to arch_debugfs_dir.

Signed-off-by: Aneesh Kumar K.V &lt;aneesh.kumar@linux.ibm.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20210812132831.233794-2-aneesh.kumar@linux.ibm.com

</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc/vdso: Make sure vdso_wrapper.o is rebuilt everytime vdso.so is rebuilt</title>
<updated>2021-04-01T13:18:09+00:00</updated>
<author>
<name>Christophe Leroy</name>
<email>christophe.leroy@csgroup.eu</email>
</author>
<published>2021-03-31T09:12:19+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=791f9e36599d94af5a76d3f74d04e16326761aae'/>
<id>791f9e36599d94af5a76d3f74d04e16326761aae</id>
<content type='text'>
Commit bce74491c300 ("powerpc/vdso: fix unnecessary rebuilds of
vgettimeofday.o") moved vdso32_wrapper.o and vdso64_wrapper.o out
of arch/powerpc/kernel/vdso[32/64]/ and removed the dependencies in
the Makefile. This leads to the wrappers not being re-build hence the
kernel embedding the old vdso library.

Add back missing dependencies to ensure vdso32_wrapper.o and vdso64_wrapper.o
are rebuilt when vdso32.so.dbg and vdso64.so.dbg are changed.

Fixes: bce74491c300 ("powerpc/vdso: fix unnecessary rebuilds of vgettimeofday.o")
Cc: stable@vger.kernel.org
Signed-off-by: Christophe Leroy &lt;christophe.leroy@csgroup.eu&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/8bb015bc98c51d8ced581415b7e3d157e18da7c9.1617181918.git.christophe.leroy@csgroup.eu
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Commit bce74491c300 ("powerpc/vdso: fix unnecessary rebuilds of
vgettimeofday.o") moved vdso32_wrapper.o and vdso64_wrapper.o out
of arch/powerpc/kernel/vdso[32/64]/ and removed the dependencies in
the Makefile. This leads to the wrappers not being re-build hence the
kernel embedding the old vdso library.

Add back missing dependencies to ensure vdso32_wrapper.o and vdso64_wrapper.o
are rebuilt when vdso32.so.dbg and vdso64.so.dbg are changed.

Fixes: bce74491c300 ("powerpc/vdso: fix unnecessary rebuilds of vgettimeofday.o")
Cc: stable@vger.kernel.org
Signed-off-by: Christophe Leroy &lt;christophe.leroy@csgroup.eu&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/8bb015bc98c51d8ced581415b7e3d157e18da7c9.1617181918.git.christophe.leroy@csgroup.eu
</pre>
</div>
</content>
</entry>
</feed>
