kernel.git/arch/s390/kernel/ipl.c, branch linux-4.16.y

s390/ipl: ensure loadparm valid flag is set

2018-04-19T06:54:11Z

commit 15deb080a6087b73089139569558965750e69d67 upstream. When loadparm is set in reipl parm block, the kernel should also set DIAG308_FLAGS_LP_VALID flag. This fixes loadparm ignoring during z/VM fcp -> ccw reipl and kvm direct boot -> ccw reipl. Cc: Reviewed-by: Heiko Carstens Signed-off-by: Vasily Gorbik Signed-off-by: Martin Schwidefsky Signed-off-by: Greg Kroah-Hartman

s390: add options to change branch prediction behaviour for the kernel

2018-02-05T12:49:17Z

Add the PPA instruction to the system entry and exit path to switch the kernel to a different branch prediction behaviour. The instructions are added via CPU alternatives and can be disabled with the "nospec" or the "nobp=0" kernel parameter. If the default behaviour selected with CONFIG_KERNEL_NOBP is set to "n" then the "nobp=1" parameter can be used to enable the changed kernel branch prediction. Acked-by: Cornelia Huck Signed-off-by: Martin Schwidefsky

s390/ipl: avoid usage of __section(.data)

2018-01-23T06:36:47Z

bss section is cleared before ipl.c code is called or global variables are used nowadays. Remove stale comment and __section(.data) from few global variables. Also removes static/global variables initialization to 0. Signed-off-by: Vasily Gorbik Signed-off-by: Martin Schwidefsky

s390: kernel: add SPDX identifiers to the remaining files

2017-11-24T14:37:12Z

It's good to have SPDX identifiers in all files to make it easier to audit the kernel tree for correct licenses. Update the arch/s390/kernel/ files with the correct SPDX license identifier based on the license text in the file itself. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This work is based on a script and data from Thomas Gleixner, Philippe Ombredanne, and Kate Stewart. Cc: Martin Schwidefsky Cc: Heiko Carstens Cc: Peter Zijlstra Cc: Ingo Molnar Cc: Arnaldo Carvalho de Melo Cc: Alexander Shishkin Cc: Jiri Olsa Cc: Namhyung Kim Cc: Thomas Gleixner Cc: Kate Stewart Cc: Philippe Ombredanne Signed-off-by: Greg Kroah-Hartman Signed-off-by: Martin Schwidefsky

s390: remove named saved segment support

2017-11-08T08:47:54Z

Remove the support to create a z/VM named saved segment (NSS). This feature is not supported since quite a while in favour of jump labels, function tracing and (now) CPU alternatives. All of these features require to write to the kernel text section which is not possible if the kernel is contained within an NSS. Given that memory savings are minimal if kernel images are shared and in addition updates of shared images are painful, the NSS feature can be removed. Reviewed-by: Hendrik Brueckner Signed-off-by: Heiko Carstens

s390/ipl: revert Load Normal semantics for LPAR CCW-type re-IPL

2017-06-14T13:35:31Z

This reverts the two commits 7afbeb6df2aa ("s390/ipl: always use load normal for CCW-type re-IPL") 0f7451ff3ab8 ("s390/ipl: use load normal for LPAR re-ipl") The two commits did not take into account that behavior of standby memory changes fundamentally if the re-IPL method is changed from Load Clear to Load Normal. In case of the old re-IPL clear method all memory that was initially in standby state will be put into standby state again within the re-IPL process. Or in other words: memory that was brought online before a re-IPL will be offline again after a reboot. Given that we use different re-IPL methods depending on the hypervisor and CCW-type vs SCSI re-IPL it is not easy to tell in advance when and why memory will stay online or will be offline after a re-IPL. This does also have other side effects, since memory that is online from the beginning will be in ZONE_NORMAL by default vs ZONE_MOVABLE for memory that is offline. Therefore, before the change, a user could online and offline memory easily since standby memory was always in ZONE_NORMAL. After the change, and a re-IPL, this depended on which memory parts were online before the re-IPL. From a usability point of view the current behavior is more than suboptimal. Therefore revert these changes until we have a better solution and get back to a consistent behavior. The bad thing about this is that the time required for a re-IPL will be significantly increased for configurations with several 100GB or 1TB of memory. Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky

s390/ipl: always use load normal for CCW-type re-IPL

2017-03-02T16:17:15Z

commit 14890678687c ("s390/ipl: use load normal for LPAR re-ipl") missed to convert one code path to use load normal semantics for re-IPL. Convert the missing code path as well. Fixes: 14890678687c ("s390/ipl: use load normal for LPAR re-ipl") Reported-by: Michael Holzheu Acked-by: Michael Holzheu Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky

s390: kernel: Audit and remove any unnecessary uses of module.h

2017-02-17T06:40:31Z

Historically a lot of these existed because we did not have a distinction between what was modular code and what was providing support to modules via EXPORT_SYMBOL and friends. That changed when we forked out support for the latter into the export.h file. This means we should be able to reduce the usage of module.h in code that is obj-y Makefile or bool Kconfig. The advantage in doing so is that module.h itself sources about 15 other headers; adding significantly to what we feed cpp, and it can obscure what headers we are effectively using. Since module.h was the source for init.h (for __init) and for export.h (for EXPORT_SYMBOL) we consider each change instance for the presence of either and replace as needed. Build testing revealed some implicit header usage that was fixed up accordingly. Signed-off-by: Paul Gortmaker Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky

s390/sclp: make early sclp code readable

2017-02-08T13:13:19Z

This patch - unifies the old sclp early code and the sclp early printk code, so they can use common functions - makes sure all sclp early functions and variables have the same "sclp_early" prefix - converts the sclp early printk code into readable code by using existing data structures instead of hard coded magic arrays - splits the early sclp code into two files: sclp_early.c and sclp_early_core.c. The core file contains everything that is required by the kernel decompressor and may not call functions not contained within the core file. Otherwise the result would be a link error. - changes interrupt handling to be completely synchronous. The old early sclp code had a small window which allowed to receive several interrupts instead of exactly the single expected interrupt. This did hide a subtle potential bug, which is fixed with this large rework. - contains a couple of small cleanups. Reviewed-by: Peter Oberparleiter Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky

s390: proper type casts for csum_partial invocations

2017-01-16T06:27:53Z

Keep sparse and other static code checkers from emitting warnings like: arch/s390/kernel/ipl.c:1549:14: warning: incorrect type in assignment (different base types) arch/s390/kernel/ipl.c:1549:14: expected unsigned int [unsigned] csum arch/s390/kernel/ipl.c:1549:14: got restricted __wsum All usages in s390 code are ok. Therefore add proper casts. Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky