<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/arch/x86/kernel/time.c, branch v4.19</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>x86/time: Correct the attribute on jiffies' definition</title>
<updated>2018-10-14T09:11:23+00:00</updated>
<author>
<name>Nathan Chancellor</name>
<email>natechancellor@gmail.com</email>
</author>
<published>2018-10-13T00:53:12+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=53c13ba8ed39e89f21a0b98f4c8a241bb44e483d'/>
<id>53c13ba8ed39e89f21a0b98f4c8a241bb44e483d</id>
<content type='text'>
Clang warns that the declaration of jiffies in include/linux/jiffies.h
doesn't match the definition in arch/x86/time/kernel.c:

arch/x86/kernel/time.c:29:42: warning: section does not match previous declaration [-Wsection]
__visible volatile unsigned long jiffies __cacheline_aligned = INITIAL_JIFFIES;
                                         ^
./include/linux/cache.h:49:4: note: expanded from macro '__cacheline_aligned'
                 __section__(".data..cacheline_aligned")))
                 ^
./include/linux/jiffies.h:81:31: note: previous attribute is here
extern unsigned long volatile __cacheline_aligned_in_smp __jiffy_arch_data jiffies;
                              ^
./arch/x86/include/asm/cache.h:20:2: note: expanded from macro '__cacheline_aligned_in_smp'
        __page_aligned_data
        ^
./include/linux/linkage.h:39:29: note: expanded from macro '__page_aligned_data'
#define __page_aligned_data     __section(.data..page_aligned) __aligned(PAGE_SIZE)
                                ^
./include/linux/compiler_attributes.h:233:56: note: expanded from macro '__section'
#define __section(S)                    __attribute__((__section__(#S)))
                                                       ^
1 warning generated.

The declaration was changed in commit 7c30f352c852 ("jiffies.h: declare
jiffies and jiffies_64 with ____cacheline_aligned_in_smp") but wasn't
updated here. Make them match so Clang no longer warns.

Fixes: 7c30f352c852 ("jiffies.h: declare jiffies and jiffies_64 with ____cacheline_aligned_in_smp")
Signed-off-by: Nathan Chancellor &lt;natechancellor@gmail.com&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Borislav Petkov &lt;bp@alien8.de&gt;
Cc: "H. Peter Anvin" &lt;hpa@zytor.com&gt;
Cc: Nick Desaulniers &lt;ndesaulniers@google.com&gt;
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20181013005311.28617-1-natechancellor@gmail.com

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Clang warns that the declaration of jiffies in include/linux/jiffies.h
doesn't match the definition in arch/x86/time/kernel.c:

arch/x86/kernel/time.c:29:42: warning: section does not match previous declaration [-Wsection]
__visible volatile unsigned long jiffies __cacheline_aligned = INITIAL_JIFFIES;
                                         ^
./include/linux/cache.h:49:4: note: expanded from macro '__cacheline_aligned'
                 __section__(".data..cacheline_aligned")))
                 ^
./include/linux/jiffies.h:81:31: note: previous attribute is here
extern unsigned long volatile __cacheline_aligned_in_smp __jiffy_arch_data jiffies;
                              ^
./arch/x86/include/asm/cache.h:20:2: note: expanded from macro '__cacheline_aligned_in_smp'
        __page_aligned_data
        ^
./include/linux/linkage.h:39:29: note: expanded from macro '__page_aligned_data'
#define __page_aligned_data     __section(.data..page_aligned) __aligned(PAGE_SIZE)
                                ^
./include/linux/compiler_attributes.h:233:56: note: expanded from macro '__section'
#define __section(S)                    __attribute__((__section__(#S)))
                                                       ^
1 warning generated.

The declaration was changed in commit 7c30f352c852 ("jiffies.h: declare
jiffies and jiffies_64 with ____cacheline_aligned_in_smp") but wasn't
updated here. Make them match so Clang no longer warns.

Fixes: 7c30f352c852 ("jiffies.h: declare jiffies and jiffies_64 with ____cacheline_aligned_in_smp")
Signed-off-by: Nathan Chancellor &lt;natechancellor@gmail.com&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Borislav Petkov &lt;bp@alien8.de&gt;
Cc: "H. Peter Anvin" &lt;hpa@zytor.com&gt;
Cc: Nick Desaulniers &lt;ndesaulniers@google.com&gt;
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20181013005311.28617-1-natechancellor@gmail.com

</pre>
</div>
</content>
</entry>
<entry>
<title>x86: Don't include linux/irq.h from asm/hardirq.h</title>
<updated>2018-08-05T07:53:13+00:00</updated>
<author>
<name>Nicolai Stange</name>
<email>nstange@suse.de</email>
</author>
<published>2018-07-29T10:15:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=447ae316670230d7d29430e2cbf1f5db4f49d14c'/>
<id>447ae316670230d7d29430e2cbf1f5db4f49d14c</id>
<content type='text'>
The next patch in this series will have to make the definition of
irq_cpustat_t available to entering_irq().

Inclusion of asm/hardirq.h into asm/apic.h would cause circular header
dependencies like

  asm/smp.h
    asm/apic.h
      asm/hardirq.h
        linux/irq.h
          linux/topology.h
            linux/smp.h
              asm/smp.h

or

  linux/gfp.h
    linux/mmzone.h
      asm/mmzone.h
        asm/mmzone_64.h
          asm/smp.h
            asm/apic.h
              asm/hardirq.h
                linux/irq.h
                  linux/irqdesc.h
                    linux/kobject.h
                      linux/sysfs.h
                        linux/kernfs.h
                          linux/idr.h
                            linux/gfp.h

and others.

This causes compilation errors because of the header guards becoming
effective in the second inclusion: symbols/macros that had been defined
before wouldn't be available to intermediate headers in the #include chain
anymore.

A possible workaround would be to move the definition of irq_cpustat_t
into its own header and include that from both, asm/hardirq.h and
asm/apic.h.

However, this wouldn't solve the real problem, namely asm/harirq.h
unnecessarily pulling in all the linux/irq.h cruft: nothing in
asm/hardirq.h itself requires it. Also, note that there are some other
archs, like e.g. arm64, which don't have that #include in their
asm/hardirq.h.

Remove the linux/irq.h #include from x86' asm/hardirq.h.

Fix resulting compilation errors by adding appropriate #includes to *.c
files as needed.

Note that some of these *.c files could be cleaned up a bit wrt. to their
set of #includes, but that should better be done from separate patches, if
at all.

Signed-off-by: Nicolai Stange &lt;nstange@suse.de&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The next patch in this series will have to make the definition of
irq_cpustat_t available to entering_irq().

Inclusion of asm/hardirq.h into asm/apic.h would cause circular header
dependencies like

  asm/smp.h
    asm/apic.h
      asm/hardirq.h
        linux/irq.h
          linux/topology.h
            linux/smp.h
              asm/smp.h

or

  linux/gfp.h
    linux/mmzone.h
      asm/mmzone.h
        asm/mmzone_64.h
          asm/smp.h
            asm/apic.h
              asm/hardirq.h
                linux/irq.h
                  linux/irqdesc.h
                    linux/kobject.h
                      linux/sysfs.h
                        linux/kernfs.h
                          linux/idr.h
                            linux/gfp.h

and others.

This causes compilation errors because of the header guards becoming
effective in the second inclusion: symbols/macros that had been defined
before wouldn't be available to intermediate headers in the #include chain
anymore.

A possible workaround would be to move the definition of irq_cpustat_t
into its own header and include that from both, asm/hardirq.h and
asm/apic.h.

However, this wouldn't solve the real problem, namely asm/harirq.h
unnecessarily pulling in all the linux/irq.h cruft: nothing in
asm/hardirq.h itself requires it. Also, note that there are some other
archs, like e.g. arm64, which don't have that #include in their
asm/hardirq.h.

Remove the linux/irq.h #include from x86' asm/hardirq.h.

Fix resulting compilation errors by adding appropriate #includes to *.c
files as needed.

Note that some of these *.c files could be cleaned up a bit wrt. to their
set of #includes, but that should better be done from separate patches, if
at all.

Signed-off-by: Nicolai Stange &lt;nstange@suse.de&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>x86/time: Unconditionally register legacy timer interrupt</title>
<updated>2018-01-14T19:18:23+00:00</updated>
<author>
<name>Peter Zijlstra</name>
<email>peterz@infradead.org</email>
</author>
<published>2017-12-22T09:20:12+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=6d671e1b85c63e7a337ba76c1a154c091545cff8'/>
<id>6d671e1b85c63e7a337ba76c1a154c091545cff8</id>
<content type='text'>
Even without a PIC/PIT the legacy timer interrupt is required for HPET in
legacy replacement mode.

Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: len.brown@intel.com
Cc: rui.zhang@intel.com
Link: https://lkml.kernel.org/r/20171222092243.382623763@infradead.org

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Even without a PIC/PIT the legacy timer interrupt is required for HPET in
legacy replacement mode.

Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: len.brown@intel.com
Cc: rui.zhang@intel.com
Link: https://lkml.kernel.org/r/20171222092243.382623763@infradead.org

</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'linus' into x86/apic, to resolve conflicts</title>
<updated>2017-11-07T09:51:10+00:00</updated>
<author>
<name>Ingo Molnar</name>
<email>mingo@kernel.org</email>
</author>
<published>2017-11-07T09:51:10+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=141d3b1daacd11bdbd6fa74c2b163093e10d17ee'/>
<id>141d3b1daacd11bdbd6fa74c2b163093e10d17ee</id>
<content type='text'>
Conflicts:
	arch/x86/include/asm/x2apic.h

Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Conflicts:
	arch/x86/include/asm/x2apic.h

Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>License cleanup: add SPDX GPL-2.0 license identifier to files with no license</title>
<updated>2017-11-02T10:10:55+00:00</updated>
<author>
<name>Greg Kroah-Hartman</name>
<email>gregkh@linuxfoundation.org</email>
</author>
<published>2017-11-01T14:07:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=b24413180f5600bcb3bb70fbed5cf186b60864bd'/>
<id>b24413180f5600bcb3bb70fbed5cf186b60864bd</id>
<content type='text'>
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier.  The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
 - file had no licensing information it it.
 - file was a */uapi/* one with no licensing information in it,
 - file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode &amp; Windriver) producing SPDX
tag:value files created by Philippe Ombredanne.  Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed.  Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
 - Files considered eligible had to be source code files.
 - Make and config files were included as candidates if they contained &gt;5
   lines of source
 - File already had some variant of a license header in it (even if &lt;5
   lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

 - when both scanners couldn't find any license traces, file was
   considered to have no license information in it, and the top level
   COPYING file license applied.

   For non */uapi/* files that summary was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0                                              11139

   and resulted in the first patch in this series.

   If that file was a */uapi/* path one, it was "GPL-2.0 WITH
   Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0 WITH Linux-syscall-note                        930

   and resulted in the second patch in this series.

 - if a file had some form of licensing information in it, and was one
   of the */uapi/* ones, it was denoted with the Linux-syscall-note if
   any GPL family license was found in the file or had no licensing in
   it (per prior point).  Results summary:

   SPDX license identifier                            # files
   ---------------------------------------------------|------
   GPL-2.0 WITH Linux-syscall-note                       270
   GPL-2.0+ WITH Linux-syscall-note                      169
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
   LGPL-2.1+ WITH Linux-syscall-note                      15
   GPL-1.0+ WITH Linux-syscall-note                       14
   ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
   LGPL-2.0+ WITH Linux-syscall-note                       4
   LGPL-2.1 WITH Linux-syscall-note                        3
   ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
   ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1

   and that resulted in the third patch in this series.

 - when the two scanners agreed on the detected license(s), that became
   the concluded license(s).

 - when there was disagreement between the two scanners (one detected a
   license but the other didn't, or they both detected different
   licenses) a manual inspection of the file occurred.

 - In most cases a manual inspection of the information in the file
   resulted in a clear resolution of the license that should apply (and
   which scanner probably needed to revisit its heuristics).

 - When it was not immediately clear, the license identifier was
   confirmed with lawyers working with the Linux Foundation.

 - If there was any question as to the appropriate license identifier,
   the file was flagged for further research and to be revisited later
   in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights.  The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
 - a full scancode scan run, collecting the matched texts, detected
   license ids and scores
 - reviewing anything where there was a license detected (about 500+
   files) to ensure that the applied SPDX license was correct
 - reviewing anything where there was no detection but the patch license
   was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
   SPDX license was correct

This produced a worksheet with 20 files needing minor correction.  This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg.  Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected.  This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.)  Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart &lt;kstewart@linuxfoundation.org&gt;
Reviewed-by: Philippe Ombredanne &lt;pombredanne@nexb.com&gt;
Reviewed-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier.  The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
 - file had no licensing information it it.
 - file was a */uapi/* one with no licensing information in it,
 - file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode &amp; Windriver) producing SPDX
tag:value files created by Philippe Ombredanne.  Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed.  Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
 - Files considered eligible had to be source code files.
 - Make and config files were included as candidates if they contained &gt;5
   lines of source
 - File already had some variant of a license header in it (even if &lt;5
   lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

 - when both scanners couldn't find any license traces, file was
   considered to have no license information in it, and the top level
   COPYING file license applied.

   For non */uapi/* files that summary was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0                                              11139

   and resulted in the first patch in this series.

   If that file was a */uapi/* path one, it was "GPL-2.0 WITH
   Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0 WITH Linux-syscall-note                        930

   and resulted in the second patch in this series.

 - if a file had some form of licensing information in it, and was one
   of the */uapi/* ones, it was denoted with the Linux-syscall-note if
   any GPL family license was found in the file or had no licensing in
   it (per prior point).  Results summary:

   SPDX license identifier                            # files
   ---------------------------------------------------|------
   GPL-2.0 WITH Linux-syscall-note                       270
   GPL-2.0+ WITH Linux-syscall-note                      169
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
   LGPL-2.1+ WITH Linux-syscall-note                      15
   GPL-1.0+ WITH Linux-syscall-note                       14
   ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
   LGPL-2.0+ WITH Linux-syscall-note                       4
   LGPL-2.1 WITH Linux-syscall-note                        3
   ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
   ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1

   and that resulted in the third patch in this series.

 - when the two scanners agreed on the detected license(s), that became
   the concluded license(s).

 - when there was disagreement between the two scanners (one detected a
   license but the other didn't, or they both detected different
   licenses) a manual inspection of the file occurred.

 - In most cases a manual inspection of the information in the file
   resulted in a clear resolution of the license that should apply (and
   which scanner probably needed to revisit its heuristics).

 - When it was not immediately clear, the license identifier was
   confirmed with lawyers working with the Linux Foundation.

 - If there was any question as to the appropriate license identifier,
   the file was flagged for further research and to be revisited later
   in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights.  The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
 - a full scancode scan run, collecting the matched texts, detected
   license ids and scores
 - reviewing anything where there was a license detected (about 500+
   files) to ensure that the applied SPDX license was correct
 - reviewing anything where there was no detection but the patch license
   was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
   SPDX license was correct

This produced a worksheet with 20 files needing minor correction.  This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg.  Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected.  This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.)  Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart &lt;kstewart@linuxfoundation.org&gt;
Reviewed-by: Philippe Ombredanne &lt;pombredanne@nexb.com&gt;
Reviewed-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>x86/apic: Initialize interrupt mode after timer init</title>
<updated>2017-09-25T13:03:17+00:00</updated>
<author>
<name>Dou Liyang</name>
<email>douly.fnst@cn.fujitsu.com</email>
</author>
<published>2017-09-13T09:12:54+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=935356cecda851d94381e1c6fea9dec443f908fe'/>
<id>935356cecda851d94381e1c6fea9dec443f908fe</id>
<content type='text'>
A cold or warm boot through BIOS sets the APIC in default interrupt
delivery mode. A dump-capture kernel will not go through a BIOS reset and
leave the interrupt delivery mode in the state which was active on the
crashed kernel, but the dump kernel startup code assumes default delivery
mode which can result in interrupt delivery/handling to fail.

To solve this problem, it's required to set up the final interrupt delivery
mode as soon as possible. As IOAPIC setup needs the timer initialized for
verifying the timer interrupt delivery mode, the earliest point is right
after timer setup in late_time_init().

That results in the following init order:

  1) Set up the legacy timer, if applicable on the platform

  2) Set up APIC/IOAPIC which includes the verification of the legacy timer
     interrupt delivery.

  3) TSC calibration

  4) Local APIC timer setup


Signed-off-by: Dou Liyang &lt;douly.fnst@cn.fujitsu.com&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: yinghai@kernel.org
Cc: bhe@redhat.com
Link: https://lkml.kernel.org/r/1505293975-26005-12-git-send-email-douly.fnst@cn.fujitsu.com

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
A cold or warm boot through BIOS sets the APIC in default interrupt
delivery mode. A dump-capture kernel will not go through a BIOS reset and
leave the interrupt delivery mode in the state which was active on the
crashed kernel, but the dump kernel startup code assumes default delivery
mode which can result in interrupt delivery/handling to fail.

To solve this problem, it's required to set up the final interrupt delivery
mode as soon as possible. As IOAPIC setup needs the timer initialized for
verifying the timer interrupt delivery mode, the earliest point is right
after timer setup in late_time_init().

That results in the following init order:

  1) Set up the legacy timer, if applicable on the platform

  2) Set up APIC/IOAPIC which includes the verification of the legacy timer
     interrupt delivery.

  3) TSC calibration

  4) Local APIC timer setup


Signed-off-by: Dou Liyang &lt;douly.fnst@cn.fujitsu.com&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: yinghai@kernel.org
Cc: bhe@redhat.com
Link: https://lkml.kernel.org/r/1505293975-26005-12-git-send-email-douly.fnst@cn.fujitsu.com

</pre>
</div>
</content>
</entry>
<entry>
<title>x86/time: Make setup_default_timer_irq() static</title>
<updated>2017-06-13T06:42:09+00:00</updated>
<author>
<name>Dou Liyang</name>
<email>douly.fnst@cn.fujitsu.com</email>
</author>
<published>2017-06-13T02:30:29+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=b1b4f2fe68393f80480545b5e67a50f7bda8e9a7'/>
<id>b1b4f2fe68393f80480545b5e67a50f7bda8e9a7</id>
<content type='text'>
This function isn't used outside of time.c, so let's mark it static.

Signed-off-by: Dou Liyang &lt;douly.fnst@cn.fujitsu.com&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Link: http://lkml.kernel.org/r/1497321029-29049-1-git-send-email-douly.fnst@cn.fujitsu.com
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This function isn't used outside of time.c, so let's mark it static.

Signed-off-by: Dou Liyang &lt;douly.fnst@cn.fujitsu.com&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Link: http://lkml.kernel.org/r/1497321029-29049-1-git-send-email-douly.fnst@cn.fujitsu.com
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>x86/asm/entry: Change all 'user_mode_vm()' calls to 'user_mode()'</title>
<updated>2015-03-23T10:14:17+00:00</updated>
<author>
<name>Andy Lutomirski</name>
<email>luto@kernel.org</email>
</author>
<published>2015-03-19T01:33:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=f39b6f0ef855a38ea17329a4e621ff97750dfcc2'/>
<id>f39b6f0ef855a38ea17329a4e621ff97750dfcc2</id>
<content type='text'>
user_mode_vm() and user_mode() are now the same.  Change all callers
of user_mode_vm() to user_mode().

The next patch will remove the definition of user_mode_vm.

Signed-off-by: Andy Lutomirski &lt;luto@kernel.org&gt;
Cc: Borislav Petkov &lt;bp@alien8.de&gt;
Cc: Brad Spengler &lt;spender@grsecurity.net&gt;
Cc: Denys Vlasenko &lt;dvlasenk@redhat.com&gt;
Cc: H. Peter Anvin &lt;hpa@zytor.com&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Link: http://lkml.kernel.org/r/43b1f57f3df70df5a08b0925897c660725015554.1426728647.git.luto@kernel.org
[ Merged to a more recent kernel. ]
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
user_mode_vm() and user_mode() are now the same.  Change all callers
of user_mode_vm() to user_mode().

The next patch will remove the definition of user_mode_vm.

Signed-off-by: Andy Lutomirski &lt;luto@kernel.org&gt;
Cc: Borislav Petkov &lt;bp@alien8.de&gt;
Cc: Brad Spengler &lt;spender@grsecurity.net&gt;
Cc: Denys Vlasenko &lt;dvlasenk@redhat.com&gt;
Cc: H. Peter Anvin &lt;hpa@zytor.com&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Link: http://lkml.kernel.org/r/43b1f57f3df70df5a08b0925897c660725015554.1426728647.git.luto@kernel.org
[ Merged to a more recent kernel. ]
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>x86_64/vdso: Remove jiffies from the vvar page</title>
<updated>2014-10-28T10:22:13+00:00</updated>
<author>
<name>Andy Lutomirski</name>
<email>luto@amacapital.net</email>
</author>
<published>2014-09-23T17:50:56+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=61a492fb1759f3e892ad0408e36d3575c5f890d0'/>
<id>61a492fb1759f3e892ad0408e36d3575c5f890d0</id>
<content type='text'>
I think that the jiffies vvar was once used for the vgetcpu
cache. That code is long gone, so let's just make jiffies be a
normal variable.

Signed-off-by: Andy Lutomirski &lt;luto@amacapital.net&gt;
Link: http://lkml.kernel.org/r/fcfee6f8749af14d96373a9e2656354ad0b95499.1411494540.git.luto@amacapital.net
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
I think that the jiffies vvar was once used for the vgetcpu
cache. That code is long gone, so let's just make jiffies be a
normal variable.

Signed-off-by: Andy Lutomirski &lt;luto@amacapital.net&gt;
Link: http://lkml.kernel.org/r/fcfee6f8749af14d96373a9e2656354ad0b95499.1411494540.git.luto@amacapital.net
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>x86: Fix non-PC platform kernel crash on boot due to NULL dereference</title>
<updated>2014-08-25T20:36:57+00:00</updated>
<author>
<name>Andy Shevchenko</name>
<email>andriy.shevchenko@linux.intel.com</email>
</author>
<published>2014-07-21T08:38:40+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=a90b858cfe27a576f7e44a456af2ee432404ee8f'/>
<id>a90b858cfe27a576f7e44a456af2ee432404ee8f</id>
<content type='text'>
Upstream commit:

  95d76acc7518d5 ("x86, irq: Count legacy IRQs by legacy_pic-&gt;nr_legacy_irqs instead of NR_IRQS_LEGACY")

removed reserved interrupts for the platforms that do not have a legacy IOAPIC.

Which breaks the boot on Intel MID platforms such as Medfield:

  BUG: unable to handle kernel NULL pointer dereference at 0000003a
  IP: [&lt;c107079a&gt;] setup_irq+0xf/0x4d [    0.000000] *pdpt = 0000000000000000 *pde = 9bbf32453167e510

The culprit is an uncoditional setting of IRQ2 which is used
as cascade IRQ on legacy platforms. It seems we have to check
if we have enough legacy IRQs reserved before we can call
setup_irq().

The fix adds such check in native_init_IRQ() and in setup_default_timer_irq().

Signed-off-by: Andy Shevchenko &lt;andriy.shevchenko@linux.intel.com&gt;
Reviewed-by: Jiang Liu &lt;jiang.liu@linux.intel.com&gt;
Reviewed-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: David Cohen &lt;david.a.cohen@linux.intel.com&gt;
Link: http://lkml.kernel.org/r/1405931920-12871-1-git-send-email-andriy.shevchenko@linux.intel.com
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Upstream commit:

  95d76acc7518d5 ("x86, irq: Count legacy IRQs by legacy_pic-&gt;nr_legacy_irqs instead of NR_IRQS_LEGACY")

removed reserved interrupts for the platforms that do not have a legacy IOAPIC.

Which breaks the boot on Intel MID platforms such as Medfield:

  BUG: unable to handle kernel NULL pointer dereference at 0000003a
  IP: [&lt;c107079a&gt;] setup_irq+0xf/0x4d [    0.000000] *pdpt = 0000000000000000 *pde = 9bbf32453167e510

The culprit is an uncoditional setting of IRQ2 which is used
as cascade IRQ on legacy platforms. It seems we have to check
if we have enough legacy IRQs reserved before we can call
setup_irq().

The fix adds such check in native_init_IRQ() and in setup_default_timer_irq().

Signed-off-by: Andy Shevchenko &lt;andriy.shevchenko@linux.intel.com&gt;
Reviewed-by: Jiang Liu &lt;jiang.liu@linux.intel.com&gt;
Reviewed-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: David Cohen &lt;david.a.cohen@linux.intel.com&gt;
Link: http://lkml.kernel.org/r/1405931920-12871-1-git-send-email-andriy.shevchenko@linux.intel.com
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
