The cr16 interval timers are not synchronized across CPUs, even with just
one dual-core CPU. This becomes visible if the machines have a longer
uptime.
Signed-off-by: Helge Deller <deller@gmx.de>
This reverts commit d97180ad68.
It triggers RCU stalls at boot with a 32-bit kernel.
Signed-off-by: Helge Deller <deller@gmx.de>
Noticed-by: John David Anglin <dave.anglin@bell.net>
Cc: stable@vger.kernel.org # v5.15+
This reverts commit afdb4a5b1d.
It triggers RCU stalls at boot with a 32-bit kernel.
Signed-off-by: Helge Deller <deller@gmx.de>
Noticed-by: John David Anglin <dave.anglin@bell.net>
Cc: stable@vger.kernel.org # v5.16+
When CPU hotplugging is enabled, the user may want to remove the
current CPU which is providing the timer ticks. If this happens
we need to find a new timesync master.
Signed-off-by: Helge Deller <deller@gmx.de>
If CONFIG_HOTPLUG_CPU is enabled, those functions will be run again
after bootup. So they need to reside in the .text section.
Signed-off-by: Helge Deller <deller@gmx.de>
In commit c8c3735997 ("parisc: Enhance detection of synchronous cr16
clocksources") I assumed that CPUs on the same physical core are syncronous.
While booting up the kernel on two different C8000 machines, one with a
dual-core PA8800 and one with a dual-core PA8900 CPU, this turned out to be
wrong. The symptom was that I saw a jump in the internal clocks printed to the
syslog and strange overall behaviour. On machines which have 4 cores (2
dual-cores) the problem isn't visible, because the current logic already marked
the cr16 clocksource unstable in this case.
This patch now marks the cr16 interval timers unstable if we have more than one
CPU in the system, and it fixes this issue.
Fixes: c8c3735997 ("parisc: Enhance detection of synchronous cr16 clocksources")
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: <stable@vger.kernel.org> # v5.15+
We check at runtime if the cr16 clocks are stable across CPUs. Only mark
the sched_clock unstable by calling clear_sched_clock_stable() if we
know that we run on a system which isn't syncronized across CPUs.
Signed-off-by: Helge Deller <deller@gmx.de>
parisc has selected CONFIG_GENERIC_CLOCKEVENTS since commit 43b1f6abd5
("parisc: Switch to generic sched_clock implementation"), but does not
appear to actually be using it, and instead calls the low-level
timekeeping functions directly.
Remove the GENERIC_CLOCKEVENTS select again, and instead convert to
the newly added legacy_timer_tick() helper.
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
The HP 730 machine returned strange errors when I tried setting the rtc
time. Add some debug code to improve the possibility to trace errors
and document that hppa probably has as Y2k38 problem.
Signed-off-by: Helge Deller <deller@gmx.de>
The read_persistent_clock() uses a timespec, which is not year 2038 safe
on 32bit systems. On parisc architecture, we have implemented generic
RTC drivers that can be used to compensate the system suspend time, but
the RTC time can not represent the nanosecond resolution, so this patch
just converts to read_persistent_clock64() with timespec64.
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Helge Deller <deller@gmx.de>
Subsystem:
- Add tracepoints
- Rework of the RTC/nvmem API to allow drivers to discard struct nvmem_config
after registration
- New range API, drivers can now expose the useful range of the RTC
- New offset API the core is now able to add an offset to the RTC time,
modifying the supported range.
- Multiple rtc_time64_to_tm fixes
- Handle time_t overflow on 32 bit platforms in the core instead of letting
drivers do crazy things.
- remove rtc_control API
New driver:
- Intersil ISL12026
Drivers:
- Drivers exposing the RTC non volatile memory have been converted to use nvmem
- Removed useless time and date validation
- Removed an indirection pattern that was a cargo cult from ancient drivers
- Removed VLA usage
- Fixed a possible race condition in probe functions
- AB8540 support is dropped from ab8500
- pcf85363 now has alarm support
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Merge tag 'rtc-4.17' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux
Pull RTC updates from Alexandre Belloni:
"This contains a few series that have been in preparation for a while
and that will help systems with RTCs that will fail in 2038, 2069 or
2100.
Subsystem:
- Add tracepoints
- Rework of the RTC/nvmem API to allow drivers to discard struct
nvmem_config after registration
- New range API, drivers can now expose the useful range of the RTC
- New offset API the core is now able to add an offset to the RTC
time, modifying the supported range.
- Multiple rtc_time64_to_tm fixes
- Handle time_t overflow on 32 bit platforms in the core instead of
letting drivers do crazy things.
- remove rtc_control API
New driver:
- Intersil ISL12026
Drivers:
- Drivers exposing the RTC non volatile memory have been converted to
use nvmem
- Removed useless time and date validation
- Removed an indirection pattern that was a cargo cult from ancient
drivers
- Removed VLA usage
- Fixed a possible race condition in probe functions
- AB8540 support is dropped from ab8500
- pcf85363 now has alarm support"
* tag 'rtc-4.17' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux: (128 commits)
rtc: snvs: Fix usage of snvs_rtc_enable
rtc: mt7622: fix module autoloading for OF platform drivers
rtc: isl12022: use true and false for boolean values
rtc: ab8500: Drop AB8540 support
rtc: remove a warning during scripts/kernel-doc step
rtc: 88pm860x: remove artificial limitation
rtc: 88pm80x: remove artificial limitation
rtc: st-lpc: remove artificial limitation
rtc: mrst: remove artificial limitation
rtc: mv: remove artificial limitation
rtc: hctosys: Ensure system time doesn't overflow time_t
parisc: time: stop validating rtc_time in .read_time
rtc: pcf85063: fix clearing bits in pcf85063_start_clock
rtc: at91sam9: Set name of regmap_config
rtc: s5m: Remove VLA usage
rtc: s5m: Move enum from rtc.h to rtc-s5m.c
rtc: remove VLA usage
rtc: Add useful timestamp definitions
rtc: Add one offset seconds to expand RTC range
rtc: Factor out the RTC range validation into rtc_valid_range()
...
The RTC core is always calling rtc_valid_tm after the read_time callback.
It is not necessary to call it just before returning from the callback.
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Acked-by: Helge Deller <deller@gmx.de>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
When run under QEMU, calling mfctl(16) creates some overhead because the
qemu timer has to be scaled and moved into the register. This patch
reduces the number of calls to mfctl(16) by moving the calls out of the
loops.
Additionally, increase the minimal time interval to 8000 cycles instead
of 500 to compensate possible QEMU delays when delivering interrupts.
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org # 4.14+
When running on qemu we know that the (emulated) cr16 cpu-internal
clocks are syncronized. So let's use them unconditionally on qemu.
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org # 4.14+
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>
For CPUs which have an unknown or invalid CPU location (physical location)
assume that their cycle counters aren't syncronized across CPUs.
Signed-off-by: Helge Deller <deller@gmx.de>
Fixes: c8c3735997 ("parisc: Enhance detection of synchronous cr16 clocksources")
Cc: stable@vger.kernel.org # 4.13+
Signed-off-by: Helge Deller <deller@gmx.de>
The cr16 clocks of the physical PARISC CPUs are usually nonsynchronous.
Nevertheless, it seems that each CPU socket (which holds two cores) of
PA8800 and PA8900 CPUs (e.g. in a C8000 workstation) is fed by the same
clock source, which makes the cr16 clocks of each CPU socket syncronous.
Let's try to detect such situations and mark the cr16 clocksource stable
on single-socket and single-core machines.
Signed-off-by: Helge Deller <deller@gmx.de>
We are going to split <linux/sched/clock.h> out of <linux/sched.h>, which
will have to be picked up from other headers and .c files.
Create a trivial placeholder <linux/sched/clock.h> file that just
maps to <linux/sched.h> to make this patch obviously correct and
bisectable.
Include the new header in the files that are going to need it.
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The cr16 interval timer of each CPU is not syncronized to other cr16
timers in other CPUs in a SMP system. So, delay the registration of the
cr16 clocksource until all CPUs have been detected and then - if we are
on a SMP machine - mark the cr16 clocksource as unstable and lower it's
rating before registering it at the clocksource framework.
This patch fixes the stalled CPU warnings which we have seen since
introduction of the cr16 clocksource.
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: <stable@vger.kernel.org> # v4.8+
There is no point in having an extra type for extra confusion. u64 is
unambiguous.
Conversion was done with the following coccinelle script:
@rem@
@@
-typedef u64 cycle_t;
@fix@
typedef cycle_t;
@@
-cycle_t
+u64
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: John Stultz <john.stultz@linaro.org>
This was entirely automated, using the script by Al:
PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*<asm/uaccess.h>'
sed -i -e "s!$PATT!#include <linux/uaccess.h>!" \
$(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h)
to do the replacement at the end of the merge window.
Requested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Restructure the timer interrupt function to better cope with missed timer irqs.
Optimize the calculation when the next interrupt should happen and skip irqs if
they would happen too shortly after exit of the irq function.
The update_process_times() call is done anyway at every timer irq, so we can
safely drop the prof_counter and prof_multiplier variables from the per_cpu
structure.
Signed-off-by: Helge Deller <deller@gmx.de>
Drop the open-coded sched_clock() function and replace it by the provided
GENERIC_SCHED_CLOCK implementation. We have seen quite some hung tasks in the
past, which seem to be fixed by this patch.
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: <stable@vger.kernel.org> # v4.7+
Signed-off-by: Helge Deller <deller@gmx.de>
The config option HAVE_UNSTABLE_SCHED_CLOCK is set automatically when compiling
for SMP. There is no need to clear the stable-clock flag via
clear_sched_clock_stable() when starting secondary CPUs, and even worse,
clearing it triggers wrong self-detected CPU stall warnings on 64bit Mako
machines.
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org # 4.7+
Commit 54b6680090 (parisc: Add native high-resolution sched_clock()
implementation) added support to use the CPU-internal cr16 counters as reliable
clocksource with the help of HAVE_UNSTABLE_SCHED_CLOCK.
Sadly the commit missed to remove the hack which prevented cr16 to become the
default clocksource even on SMP systems.
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org # 4.7+
Cleanups:
- huge cleanup of rtc-generic and char/genrtc this allowed to cleanup rtc-cmos,
rtc-sh, rtc-m68k, rtc-powerpc and rtc-parisc
- move mn10300 to rtc-cmos
Subsystem:
- fix wakealarms after hibernate
- multiples fixes for rctest
- simplify implementations of .read_alarm
New drivers:
- Maxim MAX6916
Drivers:
- ds1307: fix weekday
- m41t80: add wakeup support
- pcf85063: add support for PCF85063A variant
- rv8803: extend i2c fix and other fixes
- s35390a: fix alarm reading, this fixes instant reboot after shutdown for QNAP
TS-41x
- s3c: clock fixes
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Merge tag 'rtc-4.8' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux
Pull RTC updates from Alexandre Belloni:
"RTC for 4.8
Cleanups:
- huge cleanup of rtc-generic and char/genrtc this allowed to cleanup
rtc-cmos, rtc-sh, rtc-m68k, rtc-powerpc and rtc-parisc
- move mn10300 to rtc-cmos
Subsystem:
- fix wakealarms after hibernate
- multiples fixes for rctest
- simplify implementations of .read_alarm
New drivers:
- Maxim MAX6916
Drivers:
- ds1307: fix weekday
- m41t80: add wakeup support
- pcf85063: add support for PCF85063A variant
- rv8803: extend i2c fix and other fixes
- s35390a: fix alarm reading, this fixes instant reboot after
shutdown for QNAP TS-41x
- s3c: clock fixes"
* tag 'rtc-4.8' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux: (65 commits)
rtc: rv8803: Clear V1F when setting the time
rtc: rv8803: Stop the clock while setting the time
rtc: rv8803: Always apply the I²C workaround
rtc: rv8803: Fix read day of week
rtc: rv8803: Remove the check for valid time
rtc: rv8803: Kconfig: Indicate rx8900 support
rtc: asm9260: remove .owner field for driver
rtc: at91sam9: Fix missing spin_lock_init()
rtc: m41t80: add suspend handlers for alarm IRQ
rtc: m41t80: make it a real error message
rtc: pcf85063: Add support for the PCF85063A device
rtc: pcf85063: fix year range
rtc: hym8563: in .read_alarm set .tm_sec to 0 to signal minute accuracy
rtc: explicitly set tm_sec = 0 for drivers with minute accurancy
rtc: s3c: Add s3c_rtc_{enable/disable}_clk in s3c_rtc_setfreq()
rtc: s3c: Remove unnecessary call to disable already disabled clock
rtc: abx80x: use devm_add_action_or_reset()
rtc: m41t80: use devm_add_action_or_reset()
rtc: fix a typo and reduce three empty lines to one
rtc: s35390a: improve two comments in .set_alarm
...
The rtc-generic driver provides an architecture specific
wrapper on top of the generic rtc_class_ops abstraction,
and on pa-risc, that is implemented using an open-coded
version of rtc_time_to_tm/rtc_tm_to_time.
This changes the parisc rtc-generic device to provide its
rtc_class_ops directly, using the normal helper functions,
which makes this y2038 safe (on 32-bit) and simplifies
the implementation.
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>
Add a native implementation for the sched_clock() function which utilizes the
processor-internal cycle counter (Control Register 16) as high-resolution time
source.
With this patch we now get much more fine-grained resolutions in various
in-kernel time measurements (e.g. when viewing the function tracing logs), and
probably a more accurate scheduling on SMP systems.
There are a few specific implementation details in this patch:
1. On a 32bit kernel we emulate the higher 32bits of the required 64-bit
resolution of sched_clock() by increasing a per-cpu counter at every
wrap-around of the 32bit cycle counter.
2. In a SMP system, the cycle counters of the various CPUs are not syncronized
(similiar to the TSC in a x86_64 system). To cope with this we define
HAVE_UNSTABLE_SCHED_CLOCK and let the upper layers do the adjustment work.
3. Since we need HAVE_UNSTABLE_SCHED_CLOCK, we need to provide a cmpxchg64()
function even on a 32-bit kernel.
4. A 64-bit SMP kernel which is started on a UP system will mark the
sched_clock() implementation as "stable", which means that we don't expect any
jumps in the returned counter. This is true because we then run only on one
CPU.
Signed-off-by: Helge Deller <deller@gmx.de>
No need to use CONFIG_SMP around update_cr16_clocksource(). It checks for
num_online_cpus() beeing greater than 1, which is always 1 in UP builds.
Signed-off-by: Helge Deller <deller@gmx.de>
This was defined in asm/pdc.h which needs to include asm/page.h for
__PAGE_OFFSET. This leads to an include loop so that page.h eventually will
include pdc.h again. While this is no problem because of header guards, it is
a problem because some symbols may be undefined. Such an error is this:
In file included from include/linux/bitops.h:35:0,
from include/asm-generic/getorder.h:7,
from arch/parisc/include/asm/page.h:162,
from arch/parisc/include/asm/pdc.h:346,
from arch/parisc/include/asm/processor.h:16,
from arch/parisc/include/asm/spinlock.h:6,
from arch/parisc/include/asm/atomic.h:20,
from include/linux/atomic.h:4,
from include/linux/sysfs.h:20,
from include/linux/kobject.h:21,
from include/linux/device.h:17,
from include/linux/eisa.h:5,
from arch/parisc/kernel/pci.c:11:
arch/parisc/include/asm/bitops.h: In function ‘set_bit’:
arch/parisc/include/asm/bitops.h:82:2: error: implicit declaration of function ‘_atomic_spin_lock_irqsave’ [-Werror=implicit-function-declaration]
arch/parisc/include/asm/bitops.h:84:2: error: implicit declaration of function ‘_atomic_spin_unlock_irqrestore’ [-Werror=implicit-function-declaration]
Signed-off-by: Rolf Eike Beer <eike-kernel@sf-tec.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This converts the parisc clocksources to use clocksource_register_hz/khz
This is untested, so any assistance in testing would be appreciated!
CC: Kyle McMartin <kyle@mcmartin.ca>
CC: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Stultz <johnstul@us.ibm.com>
This patch converts the parisc architecture to use the generic
read_persistent_clock and update_persistent_clock interfaces, reducing
the amount of arch specific code we have to maintain, and allowing for
further cleanups in the future.
I have not built or tested this patch, so help from arch maintainers
would be appreciated.
Signed-off-by: John Stultz <johnstul@us.ibm.com>
Acked-by: Helge Deller <deller@gmx.de>
Signed-off-by: Kyle McMartin <kyle@mcmartin.ca>
Rewrote timer_interrupt() to properly handle the "delayed!" case.
If we used floating point math to compute the number of ticks that had
elapsed since the last timer interrupt, it could take up to 12K cycles
(emperical!) to handle the interrupt. Existing code assumed it would
never take more than 8k cycles. We end up programming Interval Timer
to a value less than "current" cycle counter. Thus have to wait until
Interval Timer "wrapped" and would then get the "delayed!" printk that
I moved below.
Since we don't really know what the upper limit is, I prefer to read
CR16 again after we've programmed it to make sure we won't have to
wait for CR16 to wrap.
Further, the printk was between reading CR16 (cycle couner) and writing CR16
(the interval timer). This would cause us to continue to set the interval
timer to a value that was "behind" the cycle counter. Rinse and repeat.
So no printk's between reading CR16 and setting next interval timer.
Tested on A500 (550 Mhz PA8600).
Signed-off-by: Grant Grundler <grundler@parisc-linux.org>
Tested-by: Kyle McMartin <kyle@mcmartin.ca>
Signed-off-by: Kyle McMartin <kyle@mcmartin.ca>
----
Kyle, Helge, and other parisc's,
Please test on 32-bit before committing.
I think I have it right but recognize I might not.
TODO: I wanted to use "do_div()" in order to get both remainder
and value back with one division op. That should help with the
latency alot but can be applied seperately from this patch.
thanks,
grant
The rtc-parisc driver is not PA-RISC specific at all, as it uses the existing
(but deprecated) generic RTC infrastructure ([gs]et_rtc_time()).
Rename the driver from rtc-parisc to rtc-generic.
Signed-off-by: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
Acked-by: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Kyle McMartin <kyle@mcmartin.ca>
This patch adds the ftrace debugging functionality to the parisc kernel.
It will currently only work with 64bit kernels, because the gcc options -pg
and -ffunction-sections can't be enabled at the same time and -ffunction-sections
is still needed to be able to link 32bit kernels.
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Kyle McMartin <kyle@mcmartin.ca>
smp_cpus_done is too early for us... before we even do a device
inventory! Move update_cr16_clocksource into the tail end of
processor_probe() and stub it out on CONFIG_SMP=n builds.
Verified that clocksource0 is properly updated to use jiffies
on an SMP build.
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
So move the code to be called by smp_cpus_done, which is
after we've figured out if there's more than one cpu
actually present.
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
