BMC/Intel-BMC/linux.git/arch/s390/kernel/processor.c, branch dev-4.10

locking/core: Introduce cpu_relax_yield()

2016-11-16T09:15:09+00:00

For spinning loops people do often use barrier() or cpu_relax(). For most architectures cpu_relax and barrier are the same, but on some architectures cpu_relax can add some latency. For example on power,sparc64 and arc, cpu_relax can shift the CPU towards other hardware threads in an SMT environment. On s390 cpu_relax does even more, it uses an hypercall to the hypervisor to give up the timeslice. In contrast to the SMT yielding this can result in larger latencies. In some places this latency is unwanted, so another variant "cpu_relax_lowlatency" was introduced. Before this is used in more and more places, lets revert the logic and provide a cpu_relax_yield that can be called in places where yielding is more important than latency. By default this is the same as cpu_relax on all architectures. Signed-off-by: Christian Borntraeger Signed-off-by: Peter Zijlstra (Intel) Cc: Catalin Marinas Cc: Heiko Carstens Cc: Linus Torvalds Cc: Martin Schwidefsky Cc: Nicholas Piggin Cc: Noam Camus Cc: Peter Zijlstra Cc: Russell King Cc: Thomas Gleixner Cc: Will Deacon Cc: linuxppc-dev@lists.ozlabs.org Cc: virtualization@lists.linux-foundation.org Cc: xen-devel@lists.xenproject.org Link: http://lkml.kernel.org/r/1477386195-32736-2-git-send-email-borntraeger@de.ibm.com Signed-off-by: Ingo Molnar

s390/cpuinfo: show maximum thread id

2016-07-04T07:25:20+00:00

Expose the maximum thread id with /proc/cpuinfo. With the new line the output looks like this: vendor_id : IBM/S390 bogomips per cpu: 20325.00 max thread id : 1 With this new interface it is possible to always tell the correct number of cpu threads potentially being used by the kernel. Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky

s390/cpuinfo: rename cpu field to cpu number

2016-06-28T07:32:26+00:00

The cpu field name within /proc/cpuinfo has a conflict with the powerpc and sparc output where it contains the cpu model name. So rename the field name to cpu number which shouldn't generate any conflicts. Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky

s390/cpuinfo: show dynamic and static cpu mhz

2016-06-13T13:58:17+00:00

Show the dynamic and static cpu mhz of each cpu. Since these values are per cpu this requires a fundamental extension of the format of /proc/cpuinfo. Historically we had only a single line per cpu and a summary at the top of the file. This format is hardly extendible if we want to add more per cpu information. Therefore this patch adds per cpu blocks at the end of /proc/cpuinfo: cpu : 0 cpu Mhz dynamic : 5504 cpu Mhz static : 5504 cpu : 1 cpu Mhz dynamic : 5504 cpu Mhz static : 5504 cpu : 2 cpu Mhz dynamic : 5504 cpu Mhz static : 5504 cpu : 3 cpu Mhz dynamic : 5504 cpu Mhz static : 5504 Right now each block contains only the dynamic and static cpu mhz, but it can be easily extended like on every other architecture. This extension is supposed to be compatible with the old format. Signed-off-by: Heiko Carstens Acked-by: Sascha Silbe Signed-off-by: Martin Schwidefsky

s390/cpuinfo: print cache info and all single cpu lines on first iteration

2016-06-13T13:58:17+00:00

Change the code to print all the current output during the first iteration. This is a preparation patch for the upcoming per cpu block extension to /proc/cpuinfo. Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky

s390: add missing include statements

2016-05-10T11:24:52+00:00

arch_mmap_rnd, cpu_have_feature, and arch_randomize_brk are all defined as globally visible variables. However the files they are defined in do not include the header files with the declaration. To avoid a possible mismatch add the missing include statements so we have proper type checking in place. Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky

s390/cpuinfo: simplify locking and skip offline cpus early

2016-05-10T11:24:48+00:00

Move the get_online_cpus() and put_online_cpus() to the start and stop operation of the seqfile ops. This way there is no need to lock cpu hotplug again and again for each single cpu. This way we can also skip offline cpus early if we simply use cpumask_next() within the next operation. Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky

s390: show virtualization support in /proc/cpuinfo

2015-11-30T11:47:11+00:00

This patch exposes the SIE capability (aka virtualization support) via /proc/cpuinfo -> "features" as "sie". As we don't want to expose this hwcap via elf, let's add a second, "internal"/non-elf capability list. The content is simply concatenated to the existing features when printing /proc/cpuinfo. We also add the defines to elf.h to keep the hwcap stuff at a common place. Acked-by: Martin Schwidefsky Signed-off-by: David Hildenbrand Signed-off-by: Christian Borntraeger

s390/diag: add a statistic for diagnose calls

2015-10-14T12:32:06+00:00

Introduce /sys/debug/kernel/diag_stat with a statistic how many diagnose calls have been done by each CPU in the system. Signed-off-by: Martin Schwidefsky

s390/module: enable generic CPU feature modalias using s390 ELF hwcaps

2015-07-22T07:58:02+00:00

Add support for the generic CPU feature modalias implementation that wires up optional CPU features to udev-based module autoprobing. The file provides definitions to map CPU features to s390 ELF hardware capabilities. Signed-off-by: Hendrik Brueckner Signed-off-by: Martin Schwidefsky