linux-stable.git/arch/x86/kernel/rtc.c, branch linux-4.3.y Linux kernel stable tree x86/paravirt: Prevent rtc_cmos platform device init on PV guests 2016-01-31T19:25:42+00:00 David Vrabel david.vrabel@citrix.com 2015-12-11T14:07:53+00:00 3e8df2e2eeeb0a056bdd3042ab2103c7d8fbee44 commit d8c98a1d1488747625ad6044d423406e17e99b7a upstream. 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 Link: http://lkml.kernel.org/r/1449842873-2613-1-git-send-email-boris.ostrovsky@oracle.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit d8c98a1d1488747625ad6044d423406e17e99b7a upstream.

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
Link: http://lkml.kernel.org/r/1449842873-2613-1-git-send-email-boris.ostrovsky@oracle.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
kernel.h: remove ancient __FUNCTION__ hack 2015-02-13T02:54:13+00:00 Rasmus Villemoes linux@rasmusvillemoes.dk 2015-02-12T23:01:31+00:00 02f1f2170d2831b3233e91091c60a66622f29e82 __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> 
__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>
x86/rtc: Remove duplicate const specifier 2015-01-23T09:35:51+00:00 Colin King colin.king@canonical.com 2015-01-14T14:07:55+00:00 d505ad1d66c9cd31db5ab0d2c7bcb2a47e5bb29e 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> 
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>
Merge branch 'x86-intel-mid-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-11-12T02:12:22+00:00 Linus Torvalds torvalds@linux-foundation.org 2013-11-12T02:12:22+00:00 dba538ff5610ee126e33a28fe713b3f108d31f2c Pull x86/intel-mid changes from Ingo Molnar: "Update the 'intel mid' (mobile internet device) platform code as Intel is rolling out more SoC designs. This gets rid of most of the 'MRST' platform code in the process, mostly by renaming and shuffling code around into their respective 'intel-mid' platform drivers" * 'x86-intel-mid-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86, intel-mid: Do not re-introduce usage of obsolete __cpuinit intel_mid: Move platform device setups to their own platform_<device>.* files x86: intel-mid: Add section for sfi device table intel-mid: sfi: Allow struct devs_id.get_platform_data to be NULL intel_mid: Moved SFI related code to sfi.c intel_mid: Added custom handler for ipc devices intel_mid: Added custom device_handler support intel_mid: Refactored sfi_parse_devs() function intel_mid: Renamed *mrst* to *intel_mid* pci: intel_mid: Return true/false in function returning bool intel_mid: Renamed *mrst* to *intel_mid* mrst: Fixed indentation issues mrst: Fixed printk/pr_* related issues 
Pull x86/intel-mid changes from Ingo Molnar:
 "Update the 'intel mid' (mobile internet device) platform code as Intel
  is rolling out more SoC designs.

  This gets rid of most of the 'MRST' platform code in the process,
  mostly by renaming and shuffling code around into their respective
  'intel-mid' platform drivers"

* 'x86-intel-mid-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86, intel-mid: Do not re-introduce usage of obsolete __cpuinit
  intel_mid: Move platform device setups to their own platform_<device>.* files
  x86: intel-mid: Add section for sfi device table
  intel-mid: sfi: Allow struct devs_id.get_platform_data to be NULL
  intel_mid: Moved SFI related code to sfi.c
  intel_mid: Added custom handler for ipc devices
  intel_mid: Added custom device_handler support
  intel_mid: Refactored sfi_parse_devs() function
  intel_mid: Renamed *mrst* to *intel_mid*
  pci: intel_mid: Return true/false in function returning bool
  intel_mid: Renamed *mrst* to *intel_mid*
  mrst: Fixed indentation issues
  mrst: Fixed printk/pr_* related issues
x86/time: Honor ACPI FADT flag indicating absence of a CMOS RTC 2013-10-26T11:36:00+00:00 Jan Beulich JBeulich@suse.com 2013-10-21T08:31:57+00:00 ee5872befc9324fa4c2583c24d7ee7120314a2b7 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> 
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>
intel_mid: Renamed *mrst* to *intel_mid* 2013-10-17T23:40:47+00:00 Kuppuswamy Sathyanarayanan sathyanarayanan.kuppuswamy@linux.intel.com 2013-10-17T22:35:29+00:00 712b6aa8731a7e148298c58cea66a5209c659e3c 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> 
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>
intel_mid: Renamed *mrst* to *intel_mid* 2013-10-17T23:40:36+00:00 Kuppuswamy Sathyanarayanan sathyanarayanan.kuppuswamy@linux.intel.com 2013-10-17T22:35:27+00:00 05454c26eb3587b56abc5eb139797ac5afb6d77a 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> 
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>
x86: Increase precision of x86_platform.get/set_wallclock() 2013-05-28T21:00:59+00:00 David Vrabel david.vrabel@citrix.com 2013-05-13T17:56:06+00:00 3565184ed0c1ea46bea5b792da5f72a83c43e49b 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> 
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>
x86: Do full rtc synchronization with ntp 2013-03-15T23:50:26+00:00 Prarit Bhargava prarit@redhat.com 2013-02-14T17:02:54+00:00 3195ef59cb42cda3aeeb24a7fd2ba1b900c4a3cc 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> 
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>
x86/time/rtc: Don't print extended CMOS year when reading RTC 2013-01-24T13:56:35+00:00 Bjorn Helgaas bhelgaas@google.com 2013-01-04T22:41:47+00:00 6125bc8b86d9da75ddac77e38f41afbf9f5de3e3 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> 
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>