linux-stable.git/drivers/cpuidle, branch v4.14.166

cpuidle: Do not unset the driver if it is there already

2019-12-17T19:39:33+00:00

commit 918c1fe9fbbe46fcf56837ff21f0ef96424e8b29 upstream.

Fix __cpuidle_set_driver() to check if any of the CPUs in the mask has
a driver different from drv already and, if so, return -EBUSY before
updating any cpuidle_drivers per-CPU pointers.

Fixes: 82467a5a885d ("cpuidle: simplify multiple driver support")
Cc: 3.11+  # 3.11+
Signed-off-by: Zhenzhong Duan 
[ rjw: Subject & changelog ]
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Greg Kroah-Hartman

cpuidle: big.LITTLE: fix refcount leak

2019-02-12T18:46:03+00:00

[ Upstream commit 9456823c842f346c74265fcd98d008d87a7eb6f5 ]

of_find_node_by_path() acquires a reference to the node
returned by it and that reference needs to be dropped by its caller.
bl_idle_init() doesn't do that, so fix it.

Signed-off-by: Yangtao Li 
Acked-by: Daniel Lezcano 
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Sasha Levin

powerpc/pseries/cpuidle: Fix preempt warning

2019-01-26T08:37:02+00:00

[ Upstream commit 2b038cbc5fcf12a7ee1cc9bfd5da1e46dacdee87 ]

When booting a pseries kernel with PREEMPT enabled, it dumps the
following warning:

   BUG: using smp_processor_id() in preemptible [00000000] code: swapper/0/1
   caller is pseries_processor_idle_init+0x5c/0x22c
   CPU: 13 PID: 1 Comm: swapper/0 Not tainted 4.20.0-rc3-00090-g12201a0128bc-dirty #828
   Call Trace:
   [c000000429437ab0] [c0000000009c8878] dump_stack+0xec/0x164 (unreliable)
   [c000000429437b00] [c0000000005f2f24] check_preemption_disabled+0x154/0x160
   [c000000429437b90] [c000000000cab8e8] pseries_processor_idle_init+0x5c/0x22c
   [c000000429437c10] [c000000000010ed4] do_one_initcall+0x64/0x300
   [c000000429437ce0] [c000000000c54500] kernel_init_freeable+0x3f0/0x500
   [c000000429437db0] [c0000000000112dc] kernel_init+0x2c/0x160
   [c000000429437e20] [c00000000000c1d0] ret_from_kernel_thread+0x5c/0x6c

This happens because the code calls get_lppaca() which calls
get_paca() and it checks if preemption is disabled through
check_preemption_disabled().

Preemption should be disabled because the per CPU variable may make no
sense if there is a preemption (and a CPU switch) after it reads the
per CPU data and when it is used.

In this device driver specifically, it is not a problem, because this
code just needs to have access to one lppaca struct, and it does not
matter if it is the current per CPU lppaca struct or not (i.e. when
there is a preemption and a CPU migration).

That said, the most appropriate fix seems to be related to avoiding
the debug_smp_processor_id() call at get_paca(), instead of calling
preempt_disable() before get_paca().

Signed-off-by: Breno Leitao 
Signed-off-by: Michael Ellerman 
Signed-off-by: Sasha Levin

cpuidle: powernv: Fix promotion from snooze if next state disabled

2018-07-03T09:24:51+00:00

commit 0a4ec6aa035a52c422eceb2ed51ed88392a3d6c2 upstream.

The commit 78eaa10f027c ("cpuidle: powernv/pseries: Auto-promotion of
snooze to deeper idle state") introduced a timeout for the snooze idle
state so that it could be eventually be promoted to a deeper idle
state. The snooze timeout value is static and set to the target
residency of the next idle state, which would train the cpuidle
governor to pick the next idle state eventually.

The unfortunate side-effect of this is that if the next idle state(s)
is disabled, the CPU will forever remain in snooze, despite the fact
that the system is completely idle, and other deeper idle states are
available.

This patch fixes the issue by dynamically setting the snooze timeout
to the target residency of the next enabled state on the device.

Before Patch:
  POWER8 : Only nap disabled.
  $ cpupower monitor sleep 30
  sleep took 30.01297 seconds and exited with status 0
                |Idle_Stats
  PKG |CORE|CPU | snoo | Nap  | Fast
     0|   8|   0| 96.41|  0.00|  0.00
     0|   8|   1| 96.43|  0.00|  0.00
     0|   8|   2| 96.47|  0.00|  0.00
     0|   8|   3| 96.35|  0.00|  0.00
     0|   8|   4| 96.37|  0.00|  0.00
     0|   8|   5| 96.37|  0.00|  0.00
     0|   8|   6| 96.47|  0.00|  0.00
     0|   8|   7| 96.47|  0.00|  0.00

  POWER9: Shallow states (stop0lite, stop1lite, stop2lite, stop0, stop1,
  stop2) disabled:
  $ cpupower monitor sleep 30
  sleep took 30.05033 seconds and exited with status 0
                |Idle_Stats
  PKG |CORE|CPU | snoo | stop | stop | stop | stop | stop | stop | stop | stop
     0|  16|   0| 89.79|  0.00|  0.00|  0.00|  0.00|  0.00|  0.00|  0.00|  0.00
     0|  16|   1| 90.12|  0.00|  0.00|  0.00|  0.00|  0.00|  0.00|  0.00|  0.00
     0|  16|   2| 90.21|  0.00|  0.00|  0.00|  0.00|  0.00|  0.00|  0.00|  0.00
     0|  16|   3| 90.29|  0.00|  0.00|  0.00|  0.00|  0.00|  0.00|  0.00|  0.00

After Patch:
  POWER8 : Only nap disabled.
  $ cpupower monitor sleep 30
  sleep took 30.01200 seconds and exited with status 0
                |Idle_Stats
  PKG |CORE|CPU | snoo | Nap  | Fast
     0|   8|   0| 16.58|  0.00| 77.21
     0|   8|   1| 18.42|  0.00| 75.38
     0|   8|   2|  4.70|  0.00| 94.09
     0|   8|   3| 17.06|  0.00| 81.73
     0|   8|   4|  3.06|  0.00| 95.73
     0|   8|   5|  7.00|  0.00| 96.80
     0|   8|   6|  1.00|  0.00| 98.79
     0|   8|   7|  5.62|  0.00| 94.17

  POWER9: Shallow states (stop0lite, stop1lite, stop2lite, stop0, stop1,
  stop2) disabled:

  $ cpupower monitor sleep 30
  sleep took 30.02110 seconds and exited with status 0
                |Idle_Stats
  PKG |CORE|CPU | snoo | stop | stop | stop | stop | stop | stop | stop | stop
     0|   0|   0|  0.69|  0.00|  0.00|  0.00|  0.00|  0.00|  0.00|  9.39| 89.70
     0|   0|   1|  0.00|  0.00|  0.00|  0.00|  0.00|  0.00|  0.00|  0.05| 93.21
     0|   0|   2|  0.00|  0.00|  0.00|  0.00|  0.00|  0.00|  0.00|  0.00| 89.93
     0|   0|   3|  0.00|  0.00|  0.00|  0.00|  0.00|  0.00|  0.00|  0.00| 93.26

Fixes: 78eaa10f027c ("cpuidle: powernv/pseries: Auto-promotion of snooze to deeper idle state")
Cc: stable@vger.kernel.org # v4.2+
Signed-off-by: Gautham R. Shenoy 
Reviewed-by: Balbir Singh 
Signed-off-by: Michael Ellerman 
Signed-off-by: Greg Kroah-Hartman

cpuidle: fix broadcast control when broadcast can not be entered

2017-12-25T13:26:30+00:00

[ Upstream commit f187851b9b4a76952b1158b86434563dd2031103 ]

When failing to enter broadcast timer mode for an idle state that
requires it, a new state is selected that does not require broadcast,
but the broadcast variable remains set. This causes
tick_broadcast_exit to be called despite not having entered broadcast
mode.

This causes the WARN_ON_ONCE(!irqs_disabled()) to trigger in some
cases. It does not appear to cause problems for code today, but seems
to violate the interface so should be fixed.

Signed-off-by: Nicholas Piggin 
Reviewed-by: Thomas Gleixner 
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

powerpc/powernv/idle: Round up latency and residency values

2017-12-17T14:08:00+00:00

[ Upstream commit 8d4e10e9ed9450e18fbbf6a8872be0eac9fd4999 ]

On PowerNV platforms, firmware provides exit latency and
target residency for each of the idle states in nano
seconds.  Cpuidle framework expects the values in micro
seconds.  Round up to nearest micro seconds to avoid errors
in cases where the values are defined as fractional micro
seconds.

Default idle state of 'snooze' has exit latency of zero.  If
other states have fractional micro second exit latency, they
would get rounded down to zero micro second and make cpuidle
framework choose deeper idle state when snooze loop is the
right choice.

Reported-by: Anton Blanchard 
Signed-off-by: Vaidyanathan Srinivasan 
Reviewed-by: Gautham R. Shenoy 
Signed-off-by: Michael Ellerman 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

ARM: cpuidle: Correct driver unregistration if init fails

2017-12-10T12:40:41+00:00

[ Upstream commit 0f87855d969a87f02048ff5ced7503465d5ab2f1 ]

If cpuidle init fails, the code misses to unregister the driver for
current CPU. Furthermore, we also need to rollback to cancel all
previous CPUs registration; but the code retrieves driver handler by
using function cpuidle_get_driver(), this function returns back
current CPU driver handler but not previous CPU's handler, which leads
to the failure handling code cannot unregister previous CPUs driver.

This commit fixes two mentioned issues, it adds error handling path
'goto out_unregister_drv' for current CPU driver unregistration; and
it is to replace cpuidle_get_driver() with cpuidle_get_cpu_driver(),
the later function can retrieve driver handler for previous CPUs
according to the CPU device handler so can unregister the driver
properly.

This patch also adds extra error handling paths 'goto out_kfree_dev'
and 'goto out_kfree_drv' and adjusts the freeing sentences for previous
CPUs; so make the code more readable for freeing 'dev' and 'drv'
structures.

Suggested-by: Daniel Lezcano 
Signed-off-by: Leo Yan 
Fixes: d50a7d8acd78 (ARM: cpuidle: Support asymmetric idle definition)
Acked-by: Daniel Lezcano 
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

Update MIPS email addresses

2017-11-03T16:02:30+00:00

MIPS will soon not be a part of Imagination Technologies, and as such
many @imgtec.com email addresses will no longer be valid. This patch
updates the addresses for those who:

 - Have 10 or more patches in mainline authored using an @imgtec.com
   email address, or any patches dated within the past year.

 - Are still with Imagination but leaving as part of the MIPS business
   unit, as determined from an internal email address list.

 - Haven't already updated their email address (ie. JamesH) or expressed
   a desire to be excluded (ie. Maciej).

 - Acked v2 or earlier of this patch, which leaves Deng-Cheng, Matt &
   myself.

New addresses are of the form firstname.lastname@mips.com, and all
verified against an internal email address list.  An entry is added to
.mailmap for each person such that get_maintainer.pl will report the new
addresses rather than @imgtec.com addresses which will soon be dead.

Instances of the affected addresses throughout the tree are then
mechanically replaced with the new @mips.com address.

Signed-off-by: Paul Burton 
Cc: Deng-Cheng Zhu 
Cc: Deng-Cheng Zhu 
Acked-by: Dengcheng Zhu 
Cc: Matt Redfearn 
Cc: Matt Redfearn 
Acked-by: Matt Redfearn 
Cc: Andrew Morton 
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: trivial@kernel.org
Signed-off-by: Linus Torvalds

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

2017-11-02T10:10:55+00:00

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 
Reviewed-by: Philippe Ombredanne 
Reviewed-by: Thomas Gleixner 
Signed-off-by: Greg Kroah-Hartman

ARM: cpuidle: Avoid memleak if init fail

2017-09-19T21:10:51+00:00

In case there are no DT idle states defined or
cpuidle_register_driver() fails, the copy of the idle driver is leaked:

    unreferenced object 0xede0dc00 (size 1024):
    comm "swapper/0", pid 1, jiffies 4294937431 (age 744.510s)
    hex dump (first 32 bytes):
    94 9e 0b c1 00 00 00 00 00 00 00 00 00 00 00 00 ................
    57 46 49 00 00 00 00 00 00 00 00 00 00 00 00 00 WFI.............
    backtrace:
    [] arm_idle_init+0x44/0x1ac
    [] do_one_initcall+0x3c/0x16c
    [] kernel_init_freeable+0x110/0x1d0
    [] kernel_init+0x8/0x114
    [] ret_from_fork+0x14/0x3c

So fix this by freeing the unregistered copy in error case.

Signed-off-by: Stefan Wahren 
Fixes: d50a7d8acd78 (ARM: cpuidle: Support asymmetric idle definition)
Signed-off-by: Rafael J. Wysocki