linux-dev/arch/mips/dec/time.c, branch linus/master

MIPS: Convert update_persistent_clock() to update_persistent_clock64()

2018-05-14T22:58:23Z

Since struct timespec is not y2038 safe on 32bit machines, this patch converts update_persistent_clock() to update_persistent_clock64() using struct timespec64. The rtc_mips_set_time() and rtc_mips_set_mmss() interfaces were using 'unsigned long' type that is not y2038 safe on 32bit machines, moreover there is only one platform implementing rtc_mips_set_time() and two platforms implementing rtc_mips_set_mmss(), so we can just make them each implement update_persistent_clock64() directly, to get that helper out of the common mips code by removing rtc_mips_set_time() and rtc_mips_set_mmss() interfaces. Signed-off-by: Baolin Wang Acked-by: Arnd Bergmann Cc: Ralf Baechle Cc: Huacai Chen Cc: Paul Burton Cc: linux-mips@linux-mips.org Signed-off-by: James Hogan

MIPS: Convert read_persistent_clock() to read_persistent_clock64()

2018-05-14T22:58:23Z

Since struct timespec is not y2038 safe on 32bit machines, this patch converts read_persistent_clock() to read_persistent_clock64() using struct timespec64, as well as converting mktime() to mktime64(). Signed-off-by: Baolin Wang Acked-by: Arnd Bergmann Cc: Ralf Baechle Cc: Huacai Chen Cc: Paul Burton Cc: linux-mips@linux-mips.org Signed-off-by: James Hogan

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

2017-11-02T10:10:55Z

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

MIPS: DECstation HRT initialization rearrangement

2013-09-13T09:56:13Z

Not all I/O ASIC versions have the free-running counter implemented, an early revision used in the 5000/1xx models aka 3MIN and 4MIN did not have it. Therefore we cannot unconditionally use it as a clock source. Fortunately if not implemented its register slot has a fixed value so it is enough if we check for the value at the end of the calibration period being the same as at the beginning. This also means we need to look for another high-precision clock source on the systems affected. The 5000/1xx can have an R4000SC processor installed where the CP0 Count register can be used as a clock source. Unfortunately all the R4k DECstations suffer from the missed timer interrupt on CP0 Count reads erratum, so we cannot use the CP0 timer as a clock source and a clock event both at a time. However we never need an R4k clock event device because all DECstations have a DS1287A RTC chip whose periodic interrupt can be used as a clock source. This gives us the following four configuration possibilities for I/O ASIC DECstations: 1. No I/O ASIC counter and no CP0 timer, e.g. R3k 5000/1xx (3MIN). 2. No I/O ASIC counter but the CP0 timer, i.e. R4k 5000/150 (4MIN). 3. The I/O ASIC counter but no CP0 timer, e.g. R3k 5000/240 (3MAX+). 4. The I/O ASIC counter and the CP0 timer, e.g. R4k 5000/260 (4MAX+). For #1 and #2 this change stops the I/O ASIC free-running counter from being installed as a clock source of a 0Hz frequency. For #2 it also arranges for the CP0 timer to be used as a clock source rather than a clock event device, because having an accurate wall clock is more important than a high-precision interval timer. For #3 there is no change. For #4 the change makes the I/O ASIC free-running counter installed as a clock source so that the CP0 timer can be used as a clock event device. Unfortunately the use of the CP0 timer as a clock event device relies on a succesful completion of c0_compare_interrupt. That never happens, because while waiting for a CP0 Compare interrupt to happen the function spins in a loop reading the CP0 Count register. This makes the CP0 Count erratum trigger reliably causing the interrupt waited for to be lost in all cases. As a result #4 resorts to using the CP0 timer as a clock source as well, just as #2. However we want to keep this separate arrangement in case (hope) c0_compare_interrupt is eventually rewritten such that it avoids the erratum. Signed-off-by: Maciej W. Rozycki Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/5825/ Signed-off-by: Ralf Baechle

MIPS: DECstation HRT calibration bug fixes

2013-09-05T18:38:28Z

This change corrects DECstation HRT calibration, by removing the following bugs: 1. Calibration period selection -- HZ / 10 has been chosen, however on DECstation computers, HZ never divides by 10, as the choice for HZ is among 128, 256 and 1024. The choice therefore results in a systematic calibration error, e.g. 6.25% for the usual choice of 128 for HZ: 128 / 10 * 10 = 120 (128 - 120) / 128 -> 6.25% The change therefore makes calibration use HZ / 8 that is always accurate for the HZ values available, getting rid of the systematic error. 2. Calibration starting point synchronisation -- the duration of a number of intervals between DS1287A periodic interrupt assertions is measured, however code does not ensure at the beginning that the interrupt has not been previously asserted. This results in a variable error of e.g. up to another 6.25% for the period of HZ / 8 (8.(3)% with the original HZ / 10 period) and the usual choice of 128 for HZ: 1 / 16 -> 6.25% 1 / 12 -> 8.(3)% The change therefore adds an initial call to ds1287_timer_state that clears any previous periodic interrupt pending. The same issue applies to both I/O ASIC counter and R4k CP0 timer calibration on DECstation systems as similar code is used in both cases and both pieces of code are covered by this fix. On an R3400 test system used this fix results in a change of the I/O ASIC clock frequency reported from values like: I/O ASIC clock frequency 23185830Hz to: I/O ASIC clock frequency 24999288Hz removing the miscalculation by 6.25% from the systematic error and (for the individual sample provided) a further 1.00% from the variable error, accordingly. The nominal I/O ASIC clock frequency is 25MHz on this system. Here's another result, with the fix applied, from a system that has both HRTs available (using an R4400 at 60MHz nominal): MIPS counter frequency 59999328Hz I/O ASIC clock frequency 24999432Hz Signed-off-by: Maciej W. Rozycki Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/5807/ Signed-off-by: Ralf Baechle

set_rtc_mmss: show warning message only once

2011-01-13T16:03:07Z

Occasionally the system gets into a state where the CMOS clock has gotten slightly ahead of current time and the periodic update of RTC fails. The message is a nuisance and repeats spamming the log. See: http://www.ntp.org/ntpfaq/NTP-s-trbl-spec.htm#Q-LINUX-SET-RTC-MMSS Rather than just removing the message, make it show only once and reduce severity since it indicates a normal and non urgent condition. Signed-off-by: Stephen Hemminger Cc: Richard Henderson Cc: Ivan Kokshaysky Cc: Matt Turner Cc: Ralf Baechle Cc: David Howells Cc: Paul Mundt Cc: Ingo Molnar Cc: "H. Peter Anvin" Cc: Thomas Gleixner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

timekeeping: Increase granularity of read_persistent_clock()

2009-08-15T08:55:46Z

The persistent clock of some architectures (e.g. s390) have a better granularity than seconds. To reduce the delta between the host clock and the guest clock in a virtualized system change the read_persistent_clock function to return a struct timespec. Signed-off-by: Martin Schwidefsky Cc: Ingo Molnar Acked-by: John Stultz Cc: Daniel Walker LKML-Reference: <20090814134811.013873340@de.ibm.com> Signed-off-by: Thomas Gleixner

MIPS: Eleminate filenames from comments

2009-08-03T16:52:40Z

They tend to get not updated when files are moved around or copied and lack any obvious use. While at it zap some only too obvious comments and as per Shinya's suggestion, add a copyright header to extable.c. Signed-off-by: Ralf Baechle Acked-by: Shinya Kuribayashi Acked-by: Thadeu Lima de Souza Cascardo

mips: use bcd2bin/bin2bcd

2008-10-20T15:52:41Z

Changes mips to use the new bcd2bin/bin2bcd functions instead of the obsolete BCD_TO_BIN/BIN_TO_BCD/BCD2BIN/BIN2BCD macros. Signed-off-by: Adrian Bunk Cc: Ralf Baechle Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[MIPS] DS1287: Add clockevent driver

2008-04-28T16:14:32Z

Signed-off-by: Yoichi Yuasa Signed-off-by: Ralf Baechle