rtc: Extend timeout for waiting for UIP to clear to 1s

commit cef9ecc8e938dd48a560f7dd9be1246359248d20 upstream.

Specs don't say anything about UIP being cleared within 10ms. They
only say that UIP

rtc: Extend timeout for waiting for UIP to clear to 1s

commit cef9ecc8e938dd48a560f7dd9be1246359248d20 upstream.

Specs don't say anything about UIP being cleared within 10ms. They
only say that UIP won't occur for another 244uS. If a long NMI occurs
while UIP is still updating it might not be possible to get valid
data in 10ms.

This has been observed in the wild that around s2idle some calls can
take up to 480ms before UIP is clear.

Adjust callers from outside an interrupt context to wait for up to a
1s instead of 10ms.

Cc: <stable@vger.kernel.org> # 6.1.y
Fixes: ec5895c0f2d8 ("rtc: mc146818-lib: extract mc146818_avoid_UIP")
Reported-by: Carsten Hatger <xmb8dsv4@gmail.com>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217626
Tested-by: Mateusz Jończyk <mat.jonczyk@o2.pl>
Reviewed-by: Mateusz Jończyk <mat.jonczyk@o2.pl>
Acked-by: Mateusz Jończyk <mat.jonczyk@o2.pl>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Link: https://lore.kernel.org/r/20231128053653.101798-5-mario.limonciello@amd.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

rtc: Add support for configuring the UIP timeout for RTC reads

commit 120931db07b49252aba2073096b595482d71857c upstream.

The UIP timeout is hardcoded to 10ms for all RTC reads, but in some
contexts

rtc: Add support for configuring the UIP timeout for RTC reads

commit 120931db07b49252aba2073096b595482d71857c upstream.

The UIP timeout is hardcoded to 10ms for all RTC reads, but in some
contexts this might not be enough time. Add a timeout parameter to
mc146818_get_time() and mc146818_get_time_callback().

If UIP timeout is configured by caller to be >=100 ms and a call
takes this long, log a warning.

Make all callers use 10ms to ensure no functional changes.

Cc: <stable@vger.kernel.org> # 6.1.y
Fixes: ec5895c0f2d8 ("rtc: mc146818-lib: extract mc146818_avoid_UIP")
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Tested-by: Mateusz Jończyk <mat.jonczyk@o2.pl>
Reviewed-by: Mateusz Jończyk <mat.jonczyk@o2.pl>
Acked-by: Mateusz Jończyk <mat.jonczyk@o2.pl>
Link: https://lore.kernel.org/r/20231128053653.101798-4-mario.limonciello@amd.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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x86/rtc: Simplify PNP ids check

compare_pnp_id() already iterates over the single linked pnp_ids list
starting with the id past to it.

So there is no need for add_rtc_cmos() to call compare_pnp_id(

x86/rtc: Simplify PNP ids check

compare_pnp_id() already iterates over the single linked pnp_ids list
starting with the id past to it.

So there is no need for add_rtc_cmos() to call compare_pnp_id()
for each id on the list.

No change in functionality intended.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: linux-kernel@vger.kernel.org

show more ...

x86/rtc: Rename mach_set_rtc_mmss() to mach_set_cmos_time()

Once upon a time, before this commit in 2013:

3195ef59cb42 ("x86: Do full rtc synchronization with ntp")

... the mach_set_rtc_mmss()

x86/rtc: Rename mach_set_rtc_mmss() to mach_set_cmos_time()

Once upon a time, before this commit in 2013:

3195ef59cb42 ("x86: Do full rtc synchronization with ntp")

... the mach_set_rtc_mmss() function set only the minutes and seconds
registers of the CMOS RTC - hence the '_mmss' postfix.

This is no longer true, so rename the function to mach_set_cmos_time().

[ mingo: Expanded changelog a bit. ]

Signed-off-by: Mateusz Jończyk <mat.jonczyk@o2.pl>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20220813131034.768527-2-mat.jonczyk@o2.pl

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x86/rtc: Rewrite & simplify mach_get_cmos_time() by deleting duplicated functionality

There are functions in drivers/rtc/rtc-mc146818-lib.c that handle
reading from / writing to the CMOS RTC clock.

x86/rtc: Rewrite & simplify mach_get_cmos_time() by deleting duplicated functionality

There are functions in drivers/rtc/rtc-mc146818-lib.c that handle
reading from / writing to the CMOS RTC clock. mach_get_cmos_time() in
arch/x86/kernel/rtc.c did not use them and was mostly a duplicate of
mc146818_get_time(). Modify mach_get_cmos_time() to use
mc146818_get_time() and remove the duplicated functionality.

mach_get_cmos_time() used a different algorithm than
mc146818_get_time(), but these functions are equivalent. The major
differences are:

- mc146818_get_time() is better refined and handles various edge
conditions,

- when the UIP ("Update in progress") bit of the RTC is set,
mach_get_cmos_time() was busy waiting with cpu_relax() while
mc146818_get_time() is using mdelay(1) in every loop iteration.
(However, there is my commit merged for Linux 5.20 / 6.0 to decrease
this period to 100us:
commit d2a632a8a117 ("rtc: mc146818-lib: reduce RTC_UIP polling period")
),

- mach_get_cmos_time() assumed that the RTC year is >= 2000, which
may not be true on some old boxes with a dead battery,

- mach_get_cmos_time() was holding the rtc_lock for a long time
and could hang if the RTC is broken or not present.

The RTC writing counterpart, mach_set_rtc_mmss() is already using
mc146818_get_time() from drivers/rtc. This was done in
commit 3195ef59cb42 ("x86: Do full rtc synchronization with ntp")
It appears that mach_get_cmos_time() was simply forgotten.

mach_get_cmos_time() is really used only in read_persistent_clock64(),
which is called only in a few places in kernel/time/timekeeping.c .

[ mingo: These changes are not supposed to change behavior, but they are
not identity transformations either, as mc146818_get_time() is a
better but different implementation of the same logic - so
regressions are possible in principle. ]

Signed-off-by: Mateusz Jończyk <mat.jonczyk@o2.pl>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20220813131034.768527-1-mat.jonczyk@o2.pl

show more ...

x86: Convert x86_platform_ops to timespec64

The x86 platform operations are fairly isolated, so it's easy to change
them from using timespec to timespec64. It has been checked that all the
users and

x86: Convert x86_platform_ops to timespec64

The x86 platform operations are fairly isolated, so it's easy to change
them from using timespec to timespec64. It has been checked that all the
users and callers are safe, and there is only one critical function that is
broken beyond 2106:

pvclock_read_wallclock() uses a 32-bit number of seconds since the epoch
to communicate the boot time between host and guest in a virtual
environment. This will work until 2106, but fixing this is outside the
scope of this change, Add a comment at least.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Acked-by: Radim Krčmář <rkrcmar@redhat.com>
Acked-by: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: jailhouse-dev@googlegroups.com
Cc: Borislav Petkov <bp@suse.de>
Cc: kvm@vger.kernel.org
Cc: y2038@lists.linaro.org
Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Cc: xen-devel@lists.xenproject.org
Cc: John Stultz <john.stultz@linaro.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Joao Martins <joao.m.martins@oracle.com>
Link: https://lkml.kernel.org/r/20180427201435.3194219-1-arnd@arndb.de

show more ...

x86/rtc: Stop using deprecated functions

rtc_time_to_tm() and rtc_tm_to_time() are deprecated because they
rely on 32bits variables and that will make rtc break in y2038/2016.

Use the proper y2038

x86/rtc: Stop using deprecated functions

rtc_time_to_tm() and rtc_tm_to_time() are deprecated because they
rely on 32bits variables and that will make rtc break in y2038/2016.

Use the proper y2038 safe functions.

Signed-off-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Stephen Boyd <stephen.boyd@linaro.org>
Cc: Miroslav Lichvar <mlichvar@redhat.com>
Cc: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Link: https://lkml.kernel.org/r/1520620971-9567-5-git-send-email-john.stultz@linaro.org

show more ...

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

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 & 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 >5
lines of source
- File already had some variant of a license header in it (even if <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 <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

timekeeping: Ignore the bogus sleep time if pm_trace is enabled

Power management suspend/resume tracing (ab)uses the RTC to store
suspend/resume information persistently. As a consequence the RTC va

timekeeping: Ignore the bogus sleep time if pm_trace is enabled

Power management suspend/resume tracing (ab)uses the RTC to store
suspend/resume information persistently. As a consequence the RTC value is
clobbered when timekeeping is resumed and tries to inject the sleep time.

Commit a4f8f6667f09 ("timekeeping: Cap array access in timekeeping_debug")
plugged a out of bounds array access in the timekeeping debug code which
was caused by the clobbered RTC value, but we still use the clobbered RTC
value for sleep time injection into kernel timekeeping, which will result
in random adjustments depending on the stored "hash" value.

To prevent this keep track of the RTC clobbering and ignore the invalid RTC
timestamp at resume. If the system resumed successfully clear the flag,
which marks the RTC as unusable, warn the user about the RTC clobber and
recommend to adjust the RTC with 'ntpdate' or 'rdate'.

[jstultz: Fixed up pr_warn formating, and implemented suggestions from Ingo]
[ tglx: Rewrote changelog ]

Originally-from: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Chen Yu <yu.c.chen@intel.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Acked-by: Pavel Machek <pavel@ucw.cz>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Xunlei Pang <xlpang@redhat.com>
Cc: Len Brown <lenb@kernel.org>
Link: http://lkml.kernel.org/r/1480372524-15181-3-git-send-email-john.stultz@linaro.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

show more ...

char/genrtc: x86: remove remnants of asm/rtc.h

Commit 3195ef59cb42 ("x86: Do full rtc synchronization with ntp") had
the side-effect of unconditionally enabling the RTC_LIB symbol on x86,
which in t

char/genrtc: x86: remove remnants of asm/rtc.h

Commit 3195ef59cb42 ("x86: Do full rtc synchronization with ntp") had
the side-effect of unconditionally enabling the RTC_LIB symbol on x86,
which in turn disables the selection of the CONFIG_RTC and
CONFIG_GEN_RTC drivers that contain a two older implementations of
the CONFIG_RTC_DRV_CMOS driver.

This removes x86 from the list for genrtc, and changes all references
to the asm/rtc.h header to instead point to the interfaces
from linux/mc146818rtc.h.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

show more ...

x86/init: Disable pnpbios and rtc for X86_SUBARCH_CE4100

As per hpa CE4100 platforms can also disable pnpbios:

http://lkml.kernel.org/r/5702B5C2.7070101@zytor.com

Then Sebastian also recently no

x86/init: Disable pnpbios and rtc for X86_SUBARCH_CE4100

As per hpa CE4100 platforms can also disable pnpbios:

http://lkml.kernel.org/r/5702B5C2.7070101@zytor.com

Then Sebastian also recently noted that CE4100 also disables
RTC probe, to do that Sebastian had long ago added the RTC
of_have_populated_dt() check, he noted that it was meant to
skip the RTC probe on all OF platforms but as of now, CE4100
was the only x86 DT using this.

We can just fold this requirement into the platform quirk
then. This now means that all of these match platform quirks
for pnpbios and RTC preferences:

* X86_SUBARCH_XEN
* X86_SUBARCH_LGUEST
* X86_SUBARCH_INTEL_MID
* X86_SUBARCH_CE4100

Also see:

http://lkml.kernel.org/r/570B52EA.60300@linutronix.de

Suggested-by: H. Peter Anvin <hpa@zytor.com>
Suggested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: andrew.cooper3@citrix.com
Cc: andriy.shevchenko@linux.intel.com
Cc: boris.ostrovsky@oracle.com
Cc: david.vrabel@citrix.com
Cc: ffainelli@freebox.fr
Cc: george.dunlap@citrix.com
Cc: glin@suse.com
Cc: jgross@suse.com
Cc: jlee@suse.com
Cc: josh@joshtriplett.org
Cc: julien.grall@linaro.org
Cc: konrad.wilk@oracle.com
Cc: kozerkov@parallels.com
Cc: lenb@kernel.org
Cc: lguest@lists.ozlabs.org
Cc: linux-acpi@vger.kernel.org
Cc: lv.zheng@intel.com
Cc: matt@codeblueprint.co.uk
Cc: mbizon@freebox.fr
Cc: rjw@rjwysocki.net
Cc: robert.moore@intel.com
Cc: rusty@rustcorp.com.au
Cc: tiwai@suse.de
Cc: toshi.kani@hp.com
Cc: xen-devel@lists.xensource.com
Link: http://lkml.kernel.org/r/1460592286-300-17-git-send-email-mcgrof@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

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x86/ACPI: Move ACPI_FADT_NO_CMOS_RTC check to ACPI boot code

This moves the ACPI specific check into the ACPI boot code,
it also takes advantage of the x86_platform.legacy.rtc which
is checked for a

x86/ACPI: Move ACPI_FADT_NO_CMOS_RTC check to ACPI boot code

This moves the ACPI specific check into the ACPI boot code,
it also takes advantage of the x86_platform.legacy.rtc which
is checked for already on the RTC initialization code. This
lets us remove the nasty #ifdefery and consolidate the checks
to use only one toggle to disable the RTC init code.

The works as RTC is initialized by device_initcall(add_rtc_cmos),
this will run late in boot on start_kernel() during rest_init(),
acpi_parse_fadt() gets called earlier during setup_arch().

Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: andrew.cooper3@citrix.com
Cc: andriy.shevchenko@linux.intel.com
Cc: bigeasy@linutronix.de
Cc: boris.ostrovsky@oracle.com
Cc: david.vrabel@citrix.com
Cc: ffainelli@freebox.fr
Cc: george.dunlap@citrix.com
Cc: glin@suse.com
Cc: jgross@suse.com
Cc: jlee@suse.com
Cc: josh@joshtriplett.org
Cc: julien.grall@linaro.org
Cc: konrad.wilk@oracle.com
Cc: kozerkov@parallels.com
Cc: lenb@kernel.org
Cc: lguest@lists.ozlabs.org
Cc: linux-acpi@vger.kernel.org
Cc: lv.zheng@intel.com
Cc: matt@codeblueprint.co.uk
Cc: mbizon@freebox.fr
Cc: rjw@rjwysocki.net
Cc: robert.moore@intel.com
Cc: rusty@rustcorp.com.au
Cc: tiwai@suse.de
Cc: toshi.kani@hp.com
Cc: xen-devel@lists.xensource.com
Link: http://lkml.kernel.org/r/1460592286-300-6-git-send-email-mcgrof@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

show more ...

x86/rtc: Replace paravirt rtc check with platform legacy quirk

We have 4 types of x86 platforms that disable RTC:

* Intel MID
* Lguest - uses paravirt
* Xen dom-U - uses paravirt
* x86 on l

x86/rtc: Replace paravirt rtc check with platform legacy quirk

We have 4 types of x86 platforms that disable RTC:

* Intel MID
* Lguest - uses paravirt
* Xen dom-U - uses paravirt
* x86 on legacy systems annotated with an ACPI legacy flag

We can consolidate all of these into a platform specific legacy
quirk set early in boot through i386_start_kernel() and through
x86_64_start_reservations(). This deals with the RTC quirks which
we can rely on through the hardware subarch, the ACPI check can
be dealt with separately.

For Xen things are bit more complex given that the @X86_SUBARCH_XEN
x86_hardware_subarch is shared on for Xen which uses the PV path for
both domU and dom0. Since the semantics for differentiating between
the two are Xen specific we provide a platform helper to help override
default legacy features -- x86_platform.set_legacy_features(). Use
of this helper is highly discouraged, its only purpose should be
to account for the lack of semantics available within your given
x86_hardware_subarch.

As per 0-day, this bumps the vmlinux size using i386-tinyconfig as
follows:

TOTAL TEXT init.text x86_early_init_platform_quirks()
+70 +62 +62 +43

Only 8 bytes overhead total, as the main increase in size is
all removed via __init.

Suggested-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Reviewed-by: Juergen Gross <jgross@suse.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: andrew.cooper3@citrix.com
Cc: andriy.shevchenko@linux.intel.com
Cc: bigeasy@linutronix.de
Cc: boris.ostrovsky@oracle.com
Cc: david.vrabel@citrix.com
Cc: ffainelli@freebox.fr
Cc: george.dunlap@citrix.com
Cc: glin@suse.com
Cc: jlee@suse.com
Cc: josh@joshtriplett.org
Cc: julien.grall@linaro.org
Cc: konrad.wilk@oracle.com
Cc: kozerkov@parallels.com
Cc: lenb@kernel.org
Cc: lguest@lists.ozlabs.org
Cc: linux-acpi@vger.kernel.org
Cc: lv.zheng@intel.com
Cc: matt@codeblueprint.co.uk
Cc: mbizon@freebox.fr
Cc: rjw@rjwysocki.net
Cc: robert.moore@intel.com
Cc: rusty@rustcorp.com.au
Cc: tiwai@suse.de
Cc: toshi.kani@hp.com
Cc: xen-devel@lists.xensource.com
Link: http://lkml.kernel.org/r/1460592286-300-5-git-send-email-mcgrof@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

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x86/paravirt: Prevent rtc_cmos platform device init on PV guests

Adding the rtc platform device in non-privileged Xen PV guests causes
an IRQ conflict because these guests do not have legacy PIC and

x86/paravirt: Prevent rtc_cmos platform device init on PV guests

Adding the rtc platform device in non-privileged Xen PV guests causes
an IRQ conflict because these guests do not have legacy PIC and may
allocate irqs in the legacy range.

In a single VCPU Xen PV guest we should have:

/proc/interrupts:
CPU0
0: 4934 xen-percpu-virq timer0
1: 0 xen-percpu-ipi spinlock0
2: 0 xen-percpu-ipi resched0
3: 0 xen-percpu-ipi callfunc0
4: 0 xen-percpu-virq debug0
5: 0 xen-percpu-ipi callfuncsingle0
6: 0 xen-percpu-ipi irqwork0
7: 321 xen-dyn-event xenbus
8: 90 xen-dyn-event hvc_console
...

But hvc_console cannot get its interrupt because it is already in use
by rtc0 and the console does not work.

genirq: Flags mismatch irq 8. 00000000 (hvc_console) vs. 00000000 (rtc0)

We can avoid this problem by realizing that unprivileged PV guests (both
Xen and lguests) are not supposed to have rtc_cmos device and so
adding it is not necessary.

Privileged guests (i.e. Xen's dom0) do use it but they should not have
irq conflicts since they allocate irqs above legacy range (above
gsi_top, in fact).

Instead of explicitly testing whether the guest is privileged we can
extend pv_info structure to include information about guest's RTC
support.

Reported-and-tested-by: Sander Eikelenboom <linux@eikelenboom.it>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: vkuznets@redhat.com
Cc: xen-devel@lists.xenproject.org
Cc: konrad.wilk@oracle.com
Cc: stable@vger.kernel.org # 4.2+
Link: http://lkml.kernel.org/r/1449842873-2613-1-git-send-email-boris.ostrovsky@oracle.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

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kernel.h: remove ancient __FUNCTION__ hack

__FUNCTION__ hasn't been treated as a string literal since gcc 3.4, so
this only helps people who only test-compile using 3.3 (compiler-gcc3.h
barks at any

kernel.h: remove ancient __FUNCTION__ hack

__FUNCTION__ hasn't been treated as a string literal since gcc 3.4, so
this only helps people who only test-compile using 3.3 (compiler-gcc3.h
barks at anything older than that). Besides, there are almost no
occurrences of __FUNCTION__ left in the tree.

[akpm@linux-foundation.org: convert remaining __FUNCTION__ references]
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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x86/rtc: Remove duplicate const specifier

Building with clang:

CC arch/x86/kernel/rtc.o
arch/x86/kernel/rtc.c:173:29: warning: duplicate 'const' declaration
specifier [-Wduplicate-decl-spe

x86/rtc: Remove duplicate const specifier

Building with clang:

CC arch/x86/kernel/rtc.o
arch/x86/kernel/rtc.c:173:29: warning: duplicate 'const' declaration
specifier [-Wduplicate-decl-specifier]
static const char * const const ids[] __initconst =

Remove the duplicate const, it is not needed and causes a warning.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Link: http://lkml.kernel.org/r/1421244475-313-1-git-send-email-colin.king@canonical.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

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x86/time: Honor ACPI FADT flag indicating absence of a CMOS RTC

Even though the omission was found only during code review
(originally in the Xen hypervisor, looking through ACPI v5 flags
and their

x86/time: Honor ACPI FADT flag indicating absence of a CMOS RTC

Even though the omission was found only during code review
(originally in the Xen hypervisor, looking through ACPI v5 flags
and their meanings and uses), we shouldn't be creating a
corresponding platform device in that case.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Cc: John Stultz <john.stultz@linaro.org>
Link: http://lkml.kernel.org/r/5265029D02000078000FC4D2@nat28.tlf.novell.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

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intel_mid: Renamed *mrst* to *intel_mid*

mrst is used as common name to represent all intel_mid type
soc's. But moorsetwon is just one of the intel_mid soc. So
renamed them to use intel_mid.

This p

intel_mid: Renamed *mrst* to *intel_mid*

mrst is used as common name to represent all intel_mid type
soc's. But moorsetwon is just one of the intel_mid soc. So
renamed them to use intel_mid.

This patch mainly renames the variables and related
functions that uses *mrst* prefix with *intel_mid*.

To ensure that there are no functional changes, I have compared
the objdump of related files before and after rename and found
the only difference is symbol and name changes.

Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Link: http://lkml.kernel.org/r/1382049336-21316-6-git-send-email-david.a.cohen@linux.intel.com
Signed-off-by: David Cohen <david.a.cohen@linux.intel.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

show more ...

intel_mid: Renamed *mrst* to *intel_mid*

Following files contains code that is common to all intel mid
soc's. So renamed them as below.

mrst/mrst.c -> intel-mid/intel-mid.c
mrst/vrtc.c

intel_mid: Renamed *mrst* to *intel_mid*

Following files contains code that is common to all intel mid
soc's. So renamed them as below.

mrst/mrst.c -> intel-mid/intel-mid.c
mrst/vrtc.c -> intel-mid/intel_mid_vrtc.c
mrst/early_printk_mrst.c -> intel-mid/intel_mid_vrtc.c
pci/mrst.c -> pci/intel_mid_pci.c

Also, renamed the corresponding header files and made changes
to the driver files that included these header files.

To ensure that there are no functional changes, I have compared
the objdump of renamed files before and after rename and found
that the only difference is file name change.

Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Link: http://lkml.kernel.org/r/1382049336-21316-4-git-send-email-david.a.cohen@linux.intel.com
Signed-off-by: David Cohen <david.a.cohen@linux.intel.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

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x86: Increase precision of x86_platform.get/set_wallclock()

All the virtualized platforms (KVM, lguest and Xen) have persistent
wallclocks that have more than one second of precision.

read_persiste

x86: Increase precision of x86_platform.get/set_wallclock()

All the virtualized platforms (KVM, lguest and Xen) have persistent
wallclocks that have more than one second of precision.

read_persistent_wallclock() and update_persistent_wallclock() allow
for nanosecond precision but their implementation on x86 with
x86_platform.get/set_wallclock() only allows for one second precision.
This means guests may see a wallclock time that is off by up to 1
second.

Make set_wallclock() and get_wallclock() take a struct timespec
parameter (which allows for nanosecond precision) so KVM and Xen
guests may start with a more accurate wallclock time and a Xen dom0
can maintain a more accurate wallclock for guests.

Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>

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x86: Do full rtc synchronization with ntp

Every 11 minutes ntp attempts to update the x86 rtc with the current
system time. Currently, the x86 code only updates the rtc if the system
time is within

x86: Do full rtc synchronization with ntp

Every 11 minutes ntp attempts to update the x86 rtc with the current
system time. Currently, the x86 code only updates the rtc if the system
time is within +/-15 minutes of the current value of the rtc. This
was done originally to avoid setting the RTC if the RTC was in localtime
mode (common with Windows dualbooting). Other architectures do a full
synchronization and now that we have better infrastructure to detect
when the RTC is in localtime, there is no reason that x86 should be
software limited to a 30 minute window.

This patch changes the behavior of the kernel to do a full synchronization
(year, month, day, hour, minute, and second) of the rtc when ntp requests
a synchronization between the system time and the rtc.

I've used the RTC library functions in this patchset as they do all the
required bounds checking.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: John Stultz <john.stultz@linaro.org>
Cc: x86@kernel.org
Cc: Matt Fleming <matt.fleming@intel.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: linux-efi@vger.kernel.org
Signed-off-by: Prarit Bhargava <prarit@redhat.com>
[jstultz: Tweak commit message, fold in build fix found by fengguang
Also add select RTC_LIB to X86, per new dependency, as found by prarit]
Signed-off-by: John Stultz <john.stultz@linaro.org>

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x86/time/rtc: Don't print extended CMOS year when reading RTC

We shouldn't print the current century every time we read the
RTC.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Thomas

x86/time/rtc: Don't print extended CMOS year when reading RTC

We shouldn't print the current century every time we read the
RTC.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20130104224146.15189.14874.stgit@bhelgaas.mtv.corp.google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

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x86: Allow tracing of functions in arch/x86/kernel/rtc.c

Move native_read_tsc() to tsc.c to allow profiling to be
re-enabled for rtc.c.

Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Cc: Pet

x86: Allow tracing of functions in arch/x86/kernel/rtc.c

Move native_read_tsc() to tsc.c to allow profiling to be
re-enabled for rtc.c.

Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/1349698050-6560-1-git-send-email-david.vrabel@citrix.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

show more ...

sections: fix section conflicts in arch/x86

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.co

sections: fix section conflicts in arch/x86

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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x86/rtc, mrst: Don't register a platform RTC device for for Intel MID platforms

Intel MID x86 platforms have a memory mapped virtual RTC
instead. No MID platform have the default ports (and
accessi

x86/rtc, mrst: Don't register a platform RTC device for for Intel MID platforms

Intel MID x86 platforms have a memory mapped virtual RTC
instead. No MID platform have the default ports (and
accessing them may do weird stuff).

Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Cc: feng.tang@intel.com
Cc: Feng Tang <feng.tang@intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

show more ...