<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/arch/powerpc/kernel/prom.c, 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/64: Move paca allocation later in boot</title>
<updated>2022-02-02T09:32:11+00:00</updated>
<author>
<name>Michael Ellerman</name>
<email>mpe@ellerman.id.au</email>
</author>
<published>2022-01-20T01:33:20+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=2e7f1e2b30b5b8aa5de6547407c68670fd227ad8'/>
<id>2e7f1e2b30b5b8aa5de6547407c68670fd227ad8</id>
<content type='text'>
Mahesh &amp; Sourabh identified two problems[1][2] with ppc64_bolted_size()
and paca allocation.

The first is that on a Radix capable machine but with "disable_radix" on
the command line, there is a window during early boot where
early_radix_enabled() is true, even though it will later become false.

  early_init_devtree:                       &lt;- early_radix_enabled() = false
    early_init_dt_scan_cpus:                &lt;- early_radix_enabled() = false
        ...
        check_cpu_pa_features:              &lt;- early_radix_enabled() = false
        ...                               ^ &lt;- early_radix_enabled() = TRUE
        allocate_paca:                    | &lt;- early_radix_enabled() = TRUE
            ...                           |
            ppc64_bolted_size:            | &lt;- early_radix_enabled() = TRUE
                if (early_radix_enabled())| &lt;- early_radix_enabled() = TRUE
                    return ULONG_MAX;     |
        ...                               |
    ...                                   | &lt;- early_radix_enabled() = TRUE
    ...                                   | &lt;- early_radix_enabled() = TRUE
    mmu_early_init_devtree()              V
    ...                                     &lt;- early_radix_enabled() = false

This causes ppc64_bolted_size() to return ULONG_MAX for the boot CPU's
paca allocation, even though later it will return a different value.
This is not currently a bug because the paca allocation is also limited
by the RMA size, but that is very fragile.

The second issue is that when using the Hash MMU, when we call
ppc64_bolted_size() for the boot CPU's paca allocation, we have not yet
detected whether 1T segments are available. That causes
ppc64_bolted_size() to return 256MB, even if the machine can actually
support up to 1T. This is usually OK, we generally have space below
256MB for one paca, but for a kdump kernel placed above 256MB it causes
the boot to fail.

At boot we cannot discover all the features of the machine
instantaneously, so there will always be some periods where we have
incomplete knowledge of the system. However both the above problems stem
from the fact that we allocate the boot CPU's paca (and paca pointers
array) before we decide which MMU we are using, or discover its exact
features.

Moving the paca allocation slightly later still can solve both the
issues described above, and means for a normal boot we don't do any
permanent allocations until after we've discovered the MMU.

Note that although we move the boot CPU's paca allocation later, we
still have a temporary paca (boot_paca) accessible via r13, so code that
does read only access to paca fields is safe. The only risk is that some
code writes to the boot_paca, and that write will then be lost when we
switch away from the boot_paca later in early_setup().

The additional code that runs before the paca allocation is primarily
mmu_early_init_devtree(), which is scanning the device tree and
populating globals and cur_cpu_spec with MMU related flags. I do not see
any additional code that writes to paca fields.

[1]: https://lore.kernel.org/r/20211018084434.217772-2-sourabhjain@linux.ibm.com
[2]: https://lore.kernel.org/r/20211018084434.217772-3-sourabhjain@linux.ibm.com

Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20220124130544.408675-1-mpe@ellerman.id.au

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Mahesh &amp; Sourabh identified two problems[1][2] with ppc64_bolted_size()
and paca allocation.

The first is that on a Radix capable machine but with "disable_radix" on
the command line, there is a window during early boot where
early_radix_enabled() is true, even though it will later become false.

  early_init_devtree:                       &lt;- early_radix_enabled() = false
    early_init_dt_scan_cpus:                &lt;- early_radix_enabled() = false
        ...
        check_cpu_pa_features:              &lt;- early_radix_enabled() = false
        ...                               ^ &lt;- early_radix_enabled() = TRUE
        allocate_paca:                    | &lt;- early_radix_enabled() = TRUE
            ...                           |
            ppc64_bolted_size:            | &lt;- early_radix_enabled() = TRUE
                if (early_radix_enabled())| &lt;- early_radix_enabled() = TRUE
                    return ULONG_MAX;     |
        ...                               |
    ...                                   | &lt;- early_radix_enabled() = TRUE
    ...                                   | &lt;- early_radix_enabled() = TRUE
    mmu_early_init_devtree()              V
    ...                                     &lt;- early_radix_enabled() = false

This causes ppc64_bolted_size() to return ULONG_MAX for the boot CPU's
paca allocation, even though later it will return a different value.
This is not currently a bug because the paca allocation is also limited
by the RMA size, but that is very fragile.

The second issue is that when using the Hash MMU, when we call
ppc64_bolted_size() for the boot CPU's paca allocation, we have not yet
detected whether 1T segments are available. That causes
ppc64_bolted_size() to return 256MB, even if the machine can actually
support up to 1T. This is usually OK, we generally have space below
256MB for one paca, but for a kdump kernel placed above 256MB it causes
the boot to fail.

At boot we cannot discover all the features of the machine
instantaneously, so there will always be some periods where we have
incomplete knowledge of the system. However both the above problems stem
from the fact that we allocate the boot CPU's paca (and paca pointers
array) before we decide which MMU we are using, or discover its exact
features.

Moving the paca allocation slightly later still can solve both the
issues described above, and means for a normal boot we don't do any
permanent allocations until after we've discovered the MMU.

Note that although we move the boot CPU's paca allocation later, we
still have a temporary paca (boot_paca) accessible via r13, so code that
does read only access to paca fields is safe. The only risk is that some
code writes to the boot_paca, and that write will then be lost when we
switch away from the boot_paca later in early_setup().

The additional code that runs before the paca allocation is primarily
mmu_early_init_devtree(), which is scanning the device tree and
populating globals and cur_cpu_spec with MMU related flags. I do not see
any additional code that writes to paca fields.

[1]: https://lore.kernel.org/r/20211018084434.217772-2-sourabhjain@linux.ibm.com
[2]: https://lore.kernel.org/r/20211018084434.217772-3-sourabhjain@linux.ibm.com

Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20220124130544.408675-1-mpe@ellerman.id.au

</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/kernel: Add __init attribute to eligible functions</title>
<updated>2021-12-23T11:33:10+00:00</updated>
<author>
<name>Nick Child</name>
<email>nick.child@ibm.com</email>
</author>
<published>2021-12-16T22:00:16+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=d276960d9296b6a9074795fe60a513abf8474e35'/>
<id>d276960d9296b6a9074795fe60a513abf8474e35</id>
<content type='text'>
Some functions defined in `arch/powerpc/kernel` (and one in `arch/powerpc/
kexec`) are deserving of an `__init` macro attribute. These functions are
only called by other initialization functions and therefore should inherit
the attribute.
Also, change function declarations in header files to include `__init`.

Signed-off-by: Nick Child &lt;nick.child@ibm.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20211216220035.605465-2-nick.child@ibm.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Some functions defined in `arch/powerpc/kernel` (and one in `arch/powerpc/
kexec`) are deserving of an `__init` macro attribute. These functions are
only called by other initialization functions and therefore should inherit
the attribute.
Also, change function declarations in header files to include `__init`.

Signed-off-by: Nick Child &lt;nick.child@ibm.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20211216220035.605465-2-nick.child@ibm.com
</pre>
</div>
</content>
</entry>
<entry>
<title>of/fdt: Rework early_init_dt_scan_memory() to call directly</title>
<updated>2021-12-16T22:07:52+00:00</updated>
<author>
<name>Rob Herring</name>
<email>robh@kernel.org</email>
</author>
<published>2021-12-15T15:01:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=1f012283e9360fb4007308f04cfaeb205e34b684'/>
<id>1f012283e9360fb4007308f04cfaeb205e34b684</id>
<content type='text'>
Use of the of_scan_flat_dt() function predates libfdt and is discouraged
as libfdt provides a nicer set of APIs. Rework
early_init_dt_scan_memory() to be called directly and use libfdt.

Cc: John Crispin &lt;john@phrozen.org&gt;
Cc: Thomas Bogendoerfer &lt;tsbogend@alpha.franken.de&gt;
Cc: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Cc: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Cc: Paul Mackerras &lt;paulus@samba.org&gt;
Cc: Frank Rowand &lt;frowand.list@gmail.com&gt;
Cc: linux-mips@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Reviewed-by: Frank Rowand &lt;frank.rowand@sony.com&gt;
Signed-off-by: Rob Herring &lt;robh@kernel.org&gt;
Tested-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20211215150102.1303588-1-robh@kernel.org
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Use of the of_scan_flat_dt() function predates libfdt and is discouraged
as libfdt provides a nicer set of APIs. Rework
early_init_dt_scan_memory() to be called directly and use libfdt.

Cc: John Crispin &lt;john@phrozen.org&gt;
Cc: Thomas Bogendoerfer &lt;tsbogend@alpha.franken.de&gt;
Cc: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Cc: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Cc: Paul Mackerras &lt;paulus@samba.org&gt;
Cc: Frank Rowand &lt;frowand.list@gmail.com&gt;
Cc: linux-mips@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Reviewed-by: Frank Rowand &lt;frank.rowand@sony.com&gt;
Signed-off-by: Rob Herring &lt;robh@kernel.org&gt;
Tested-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20211215150102.1303588-1-robh@kernel.org
</pre>
</div>
</content>
</entry>
<entry>
<title>of/fdt: Rework early_init_dt_scan_root() to call directly</title>
<updated>2021-12-16T22:07:48+00:00</updated>
<author>
<name>Rob Herring</name>
<email>robh@kernel.org</email>
</author>
<published>2021-11-18T18:12:11+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=d665881d2171b62ca1ea23be89be6f2a8a330bb2'/>
<id>d665881d2171b62ca1ea23be89be6f2a8a330bb2</id>
<content type='text'>
Use of the of_scan_flat_dt() function predates libfdt and is discouraged
as libfdt provides a nicer set of APIs. Rework early_init_dt_scan_root()
to be called directly and use libfdt.

Cc: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Cc: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Cc: Paul Mackerras &lt;paulus@samba.org&gt;
Cc: Frank Rowand &lt;frowand.list@gmail.com&gt;
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Rob Herring &lt;robh@kernel.org&gt;
Reviewed-by: Frank Rowand &lt;frank.rowand@sony.com&gt;
Link: https://lore.kernel.org/r/20211118181213.1433346-3-robh@kernel.org
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Use of the of_scan_flat_dt() function predates libfdt and is discouraged
as libfdt provides a nicer set of APIs. Rework early_init_dt_scan_root()
to be called directly and use libfdt.

Cc: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Cc: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Cc: Paul Mackerras &lt;paulus@samba.org&gt;
Cc: Frank Rowand &lt;frowand.list@gmail.com&gt;
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Rob Herring &lt;robh@kernel.org&gt;
Reviewed-by: Frank Rowand &lt;frank.rowand@sony.com&gt;
Link: https://lore.kernel.org/r/20211118181213.1433346-3-robh@kernel.org
</pre>
</div>
</content>
</entry>
<entry>
<title>of/fdt: Rework early_init_dt_scan_chosen() to call directly</title>
<updated>2021-12-16T22:07:41+00:00</updated>
<author>
<name>Rob Herring</name>
<email>robh@kernel.org</email>
</author>
<published>2021-11-18T18:12:10+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=60f20d84dc813f1342771a3e4f06d89da26dc412'/>
<id>60f20d84dc813f1342771a3e4f06d89da26dc412</id>
<content type='text'>
Use of the of_scan_flat_dt() function predates libfdt and is discouraged
as libfdt provides a nicer set of APIs. Rework
early_init_dt_scan_chosen() to be called directly and use libfdt.

Cc: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Cc: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Cc: Paul Mackerras &lt;paulus@samba.org&gt;
Cc: Frank Rowand &lt;frowand.list@gmail.com&gt;
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Rob Herring &lt;robh@kernel.org&gt;
Reviewed-by: Frank Rowand &lt;frank.rowand@sony.com&gt;
Link: https://lore.kernel.org/r/20211118181213.1433346-2-robh@kernel.org
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Use of the of_scan_flat_dt() function predates libfdt and is discouraged
as libfdt provides a nicer set of APIs. Rework
early_init_dt_scan_chosen() to be called directly and use libfdt.

Cc: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Cc: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Cc: Paul Mackerras &lt;paulus@samba.org&gt;
Cc: Frank Rowand &lt;frowand.list@gmail.com&gt;
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Rob Herring &lt;robh@kernel.org&gt;
Reviewed-by: Frank Rowand &lt;frank.rowand@sony.com&gt;
Link: https://lore.kernel.org/r/20211118181213.1433346-2-robh@kernel.org
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc/64s: Move hash MMU support code under CONFIG_PPC_64S_HASH_MMU</title>
<updated>2021-12-09T11:41:13+00:00</updated>
<author>
<name>Nicholas Piggin</name>
<email>npiggin@gmail.com</email>
</author>
<published>2021-12-01T14:41:52+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=387e220a2e5e630794e1f5219ed6f11e56271c21'/>
<id>387e220a2e5e630794e1f5219ed6f11e56271c21</id>
<content type='text'>
Compiling out hash support code when CONFIG_PPC_64S_HASH_MMU=n saves
128kB kernel image size (90kB text) on powernv_defconfig minus KVM,
350kB on pseries_defconfig minus KVM, 40kB on a tiny config.

Signed-off-by: Nicholas Piggin &lt;npiggin@gmail.com&gt;
[mpe: Fixup defined(ARCH_HAS_MEMREMAP_COMPAT_ALIGN), which needs CONFIG.
      Fix radix_enabled() use in setup_initial_memory_limit(). Add some
      stubs to reduce number of ifdefs.]
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20211201144153.2456614-18-npiggin@gmail.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Compiling out hash support code when CONFIG_PPC_64S_HASH_MMU=n saves
128kB kernel image size (90kB text) on powernv_defconfig minus KVM,
350kB on pseries_defconfig minus KVM, 40kB on a tiny config.

Signed-off-by: Nicholas Piggin &lt;npiggin@gmail.com&gt;
[mpe: Fixup defined(ARCH_HAS_MEMREMAP_COMPAT_ALIGN), which needs CONFIG.
      Fix radix_enabled() use in setup_initial_memory_limit(). Add some
      stubs to reduce number of ifdefs.]
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20211201144153.2456614-18-npiggin@gmail.com
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'kbuild-v5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild</title>
<updated>2021-09-03T22:33:47+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2021-09-03T22:33:47+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=b250e6d141ce4f0d0ada60e4b5db577050e5feb0'/>
<id>b250e6d141ce4f0d0ada60e4b5db577050e5feb0</id>
<content type='text'>
Pull Kbuild updates from Masahiro Yamada:

 - Add -s option (strict mode) to merge_config.sh to make it fail when
   any symbol is redefined.

 - Show a warning if a different compiler is used for building external
   modules.

 - Infer --target from ARCH for CC=clang to let you cross-compile the
   kernel without CROSS_COMPILE.

 - Make the integrated assembler default (LLVM_IAS=1) for CC=clang.

 - Add &lt;linux/stdarg.h&gt; to the kernel source instead of borrowing
   &lt;stdarg.h&gt; from the compiler.

 - Add Nick Desaulniers as a Kbuild reviewer.

 - Drop stale cc-option tests.

 - Fix the combination of CONFIG_TRIM_UNUSED_KSYMS and CONFIG_LTO_CLANG
   to handle symbols in inline assembly.

 - Show a warning if 'FORCE' is missing for if_changed rules.

 - Various cleanups

* tag 'kbuild-v5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (39 commits)
  kbuild: redo fake deps at include/ksym/*.h
  kbuild: clean up objtool_args slightly
  modpost: get the *.mod file path more simply
  checkkconfigsymbols.py: Fix the '--ignore' option
  kbuild: merge vmlinux_link() between ARCH=um and other architectures
  kbuild: do not remove 'linux' link in scripts/link-vmlinux.sh
  kbuild: merge vmlinux_link() between the ordinary link and Clang LTO
  kbuild: remove stale *.symversions
  kbuild: remove unused quiet_cmd_update_lto_symversions
  gen_compile_commands: extract compiler command from a series of commands
  x86: remove cc-option-yn test for -mtune=
  arc: replace cc-option-yn uses with cc-option
  s390: replace cc-option-yn uses with cc-option
  ia64: move core-y in arch/ia64/Makefile to arch/ia64/Kbuild
  sparc: move the install rule to arch/sparc/Makefile
  security: remove unneeded subdir-$(CONFIG_...)
  kbuild: sh: remove unused install script
  kbuild: Fix 'no symbols' warning when CONFIG_TRIM_UNUSD_KSYMS=y
  kbuild: Switch to 'f' variants of integrated assembler flag
  kbuild: Shuffle blank line to improve comment meaning
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull Kbuild updates from Masahiro Yamada:

 - Add -s option (strict mode) to merge_config.sh to make it fail when
   any symbol is redefined.

 - Show a warning if a different compiler is used for building external
   modules.

 - Infer --target from ARCH for CC=clang to let you cross-compile the
   kernel without CROSS_COMPILE.

 - Make the integrated assembler default (LLVM_IAS=1) for CC=clang.

 - Add &lt;linux/stdarg.h&gt; to the kernel source instead of borrowing
   &lt;stdarg.h&gt; from the compiler.

 - Add Nick Desaulniers as a Kbuild reviewer.

 - Drop stale cc-option tests.

 - Fix the combination of CONFIG_TRIM_UNUSED_KSYMS and CONFIG_LTO_CLANG
   to handle symbols in inline assembly.

 - Show a warning if 'FORCE' is missing for if_changed rules.

 - Various cleanups

* tag 'kbuild-v5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (39 commits)
  kbuild: redo fake deps at include/ksym/*.h
  kbuild: clean up objtool_args slightly
  modpost: get the *.mod file path more simply
  checkkconfigsymbols.py: Fix the '--ignore' option
  kbuild: merge vmlinux_link() between ARCH=um and other architectures
  kbuild: do not remove 'linux' link in scripts/link-vmlinux.sh
  kbuild: merge vmlinux_link() between the ordinary link and Clang LTO
  kbuild: remove stale *.symversions
  kbuild: remove unused quiet_cmd_update_lto_symversions
  gen_compile_commands: extract compiler command from a series of commands
  x86: remove cc-option-yn test for -mtune=
  arc: replace cc-option-yn uses with cc-option
  s390: replace cc-option-yn uses with cc-option
  ia64: move core-y in arch/ia64/Makefile to arch/ia64/Kbuild
  sparc: move the install rule to arch/sparc/Makefile
  security: remove unneeded subdir-$(CONFIG_...)
  kbuild: sh: remove unused install script
  kbuild: Fix 'no symbols' warning when CONFIG_TRIM_UNUSD_KSYMS=y
  kbuild: Switch to 'f' variants of integrated assembler flag
  kbuild: Shuffle blank line to improve comment meaning
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc/prom: Fix unused variable ‘reserve_map’ when CONFIG_PPC32 is not set</title>
<updated>2021-08-23T09:28:21+00:00</updated>
<author>
<name>Cédric Le Goater</name>
<email>clg@kaod.org</email>
</author>
<published>2021-08-23T09:00:38+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=3accc0faef081b6813967b34f7d05a3edb855cbd'/>
<id>3accc0faef081b6813967b34f7d05a3edb855cbd</id>
<content type='text'>
This fixes a compile error with W=1.

arch/powerpc/kernel/prom.c: In function ‘early_reserve_mem’:
arch/powerpc/kernel/prom.c:625:10: error: variable ‘reserve_map’ set but not used [-Werror=unused-but-set-variable]
  __be64 *reserve_map;
          ^~~~~~~~~~~
cc1: all warnings being treated as errors

Signed-off-by: Cédric Le Goater &lt;clg@kaod.org&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20210823090039.166120-2-clg@kaod.org

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This fixes a compile error with W=1.

arch/powerpc/kernel/prom.c: In function ‘early_reserve_mem’:
arch/powerpc/kernel/prom.c:625:10: error: variable ‘reserve_map’ set but not used [-Werror=unused-but-set-variable]
  __be64 *reserve_map;
          ^~~~~~~~~~~
cc1: all warnings being treated as errors

Signed-off-by: Cédric Le Goater &lt;clg@kaod.org&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20210823090039.166120-2-clg@kaod.org

</pre>
</div>
</content>
</entry>
<entry>
<title>isystem: trim/fixup stdarg.h and other headers</title>
<updated>2021-08-19T00:02:55+00:00</updated>
<author>
<name>Alexey Dobriyan</name>
<email>adobriyan@gmail.com</email>
</author>
<published>2021-08-02T20:40:31+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=39f75da7bcc829ddc4d40bb60d0e95520de7898b'/>
<id>39f75da7bcc829ddc4d40bb60d0e95520de7898b</id>
<content type='text'>
Delete/fixup few includes in anticipation of global -isystem compile
option removal.

Note: crypto/aegis128-neon-inner.c keeps &lt;stddef.h&gt; due to redefinition
of uintptr_t error (one definition comes from &lt;stddef.h&gt;, another from
&lt;linux/types.h&gt;).

Signed-off-by: Alexey Dobriyan &lt;adobriyan@gmail.com&gt;
Signed-off-by: Masahiro Yamada &lt;masahiroy@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Delete/fixup few includes in anticipation of global -isystem compile
option removal.

Note: crypto/aegis128-neon-inner.c keeps &lt;stddef.h&gt; due to redefinition
of uintptr_t error (one definition comes from &lt;stddef.h&gt;, another from
&lt;linux/types.h&gt;).

Signed-off-by: Alexey Dobriyan &lt;adobriyan@gmail.com&gt;
Signed-off-by: Masahiro Yamada &lt;masahiroy@kernel.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
