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* s390/smp: convert cpuhp_setup_state() return code to zero on successHeiko Carstens2017-08-231-0/+1
| | | | | | | | | cpuhp_setup_state() returns a state number on CPUHP_AP_ONLINE_DYN if no error occurred. Therefore convert the return code to zero before using it as exit code for s390_smp_init(). Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/smp: fix false positive kmemleak of mcesa data structureChristian Borntraeger2017-06-121-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I get number of CPUs - 1 kmemleak hits like unreferenced object 0x37ec6f000 (size 1024): comm "swapper/0", pid 1, jiffies 4294937330 (age 889.690s) hex dump (first 32 bytes): 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk backtrace: [<000000000034a848>] kmem_cache_alloc+0x2b8/0x3d0 [<00000000001164de>] __cpu_up+0x456/0x488 [<000000000016f60c>] bringup_cpu+0x4c/0xd0 [<000000000016d5d2>] cpuhp_invoke_callback+0xe2/0x9e8 [<000000000016f3c6>] cpuhp_up_callbacks+0x5e/0x110 [<000000000016f988>] _cpu_up+0xe0/0x158 [<000000000016faf0>] do_cpu_up+0xf0/0x110 [<0000000000dae1ee>] smp_init+0x126/0x130 [<0000000000d9bd04>] kernel_init_freeable+0x174/0x2e0 [<000000000089fc62>] kernel_init+0x2a/0x148 [<00000000008adce2>] kernel_thread_starter+0x6/0xc [<00000000008adcdc>] kernel_thread_starter+0x0/0xc [<ffffffffffffffff>] 0xffffffffffffffff The pointer of this data structure is stored in the prefix page of that CPU together with some extra bits ORed into the the low bits. Mark the data structure as non-leak. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* Merge branch 'guarded-storage' into 'features' to make merging withMartin Schwidefsky2017-03-221-5/+38
|\ | | | | | | the KVM tree easier.
| * s390: add a system call for guarded storageMartin Schwidefsky2017-03-221-5/+38
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This adds a new system call to enable the use of guarded storage for user space processes. The system call takes two arguments, a command and pointer to a guarded storage control block: s390_guarded_storage(int command, struct gs_cb *gs_cb); The second argument is relevant only for the GS_SET_BC_CB command. The commands in detail: 0 - GS_ENABLE Enable the guarded storage facility for the current task. The initial content of the guarded storage control block will be all zeros. After the enablement the user space code can use load-guarded-storage-controls instruction (LGSC) to load an arbitrary control block. While a task is enabled the kernel will save and restore the current content of the guarded storage registers on context switch. 1 - GS_DISABLE Disables the use of the guarded storage facility for the current task. The kernel will cease to save and restore the content of the guarded storage registers, the task specific content of these registers is lost. 2 - GS_SET_BC_CB Set a broadcast guarded storage control block. This is called per thread and stores a specific guarded storage control block in the task struct of the current task. This control block will be used for the broadcast event GS_BROADCAST. 3 - GS_CLEAR_BC_CB Clears the broadcast guarded storage control block. The guarded- storage control block is removed from the task struct that was established by GS_SET_BC_CB. 4 - GS_BROADCAST Sends a broadcast to all thread siblings of the current task. Every sibling that has established a broadcast guarded storage control block will load this control block and will be enabled for guarded storage. The broadcast guarded storage control block is used up, a second broadcast without a refresh of the stored control block with GS_SET_BC_CB will not have any effect. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* | s390/smp: fix ipl from cpu with non-zero addressHeiko Carstens2017-03-221-3/+2Star
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit af51160ebd3c ("s390/smp: initialize cpu_present_mask in setup_arch") initializes the cpu_present_mask much earlier than before. However the cpu detection code relies on the fact that iff logical cpu 0 is marked present then also the corresponding physical cpu address within the pcpu_devices array slot is valid. Since commit 44fd22992cb7 ("[PATCH] Register the boot-cpu in the cpu maps earlier") this assumption is not true anymore. The patch marks logical cpu 0 as present in common code without that architecture code had a chance to setup the logical to physical map. With that change the cpu detection code assumes that the physical cpu address of cpu 0 is also 0, which is not necessarily true. Subsequently the physical cpu address of the ipl cpu will be mapped to a different logical cpu. If that cpu is brought online later the ipl cpu will send itself an initial cpu reset sigp signal. This in turn completely resets the ipl cpu and the system stops working. A dump of such a system looks like a "store status" has been forgotten. But actually the kernel itself removed all traces which would allow to easily tell what went wrong. To fix this initialize the logical to physical cpu address already in smp_setup_processor_id(). In addition remove the initialization of the cpu_present_mask and cpu_online_mask for cpu 0, since that has already been done. Also add a sanity check, just in case common code will be changed again... The problem can be easily reproduced within a z/VM guest: > chcpu -d 0 > vmcp ipl Fixes: af51160ebd3c ("s390/smp: initialize cpu_present_mask in setup_arch") Reported-by: Sebastian Ott <sebott@linux.vnet.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* sched/headers: Prepare for new header dependencies before moving code to ↵Ingo Molnar2017-03-021-0/+1
| | | | | | | | | | | | | | | | | | | | <linux/sched/task_stack.h> We are going to split <linux/sched/task_stack.h> out of <linux/sched.h>, which will have to be picked up from other headers and a couple of .c files. Create a trivial placeholder <linux/sched/task_stack.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>
* sched/headers: Prepare for new header dependencies before moving code to ↵Ingo Molnar2017-03-021-0/+1
| | | | | | | | | | | | | | | | | | | | <linux/sched/hotplug.h> We are going to split <linux/sched/hotplug.h> out of <linux/sched.h>, which will have to be picked up from other headers and a couple of .c files. Create a trivial placeholder <linux/sched/hotplug.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>
* s390: kernel: Audit and remove any unnecessary uses of module.hPaul Gortmaker2017-02-171-1/+1
| | | | | | | | | | | | | | | | | | | | | | 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 <paul.gortmaker@windriver.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* Merge branch 'for-linus' of ↵Linus Torvalds2016-12-141-19/+13Star
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 updates from Martin Schwidefsky: "The main bulk of the s390 patches for the 4.10 merge window: - Add support for the contiguous memory allocator. - The recovery for I/O errors in the dasd device driver is improved, the driver will now remove channel paths that are not working properly. - Additional fields are added to /proc/sysinfo, the extended partition name and the partition UUID. - New naming for PCI devices with system defined UIDs. - The last few remaining alloc_bootmem calls are converted to memblock. - The thread_info structure is stripped down and moved to the task_struct. The only field left in thread_info is the flags field. - Rework of the arch topology code to fix a fake numa issue. - Refactoring of the atomic primitives and add a new preempt_count implementation. - Clocksource steering for the STP sync check offsets. - The s390 specific headers are changed to make them usable with CLANG. - Bug fixes and cleanup" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (70 commits) s390/cpumf: Use configuration level indication for sampling data s390: provide memmove implementation s390: cleanup arch/s390/kernel Makefile s390: fix initrd corruptions with gcov/kcov instrumented kernels s390: exclude early C code from gcov profiling s390/dasd: channel path aware error recovery s390/dasd: extend dasd path handling s390: remove unused labels from entry.S s390/vmlogrdr: fix IUCV buffer allocation s390/crypto: unlock on error in prng_tdes_read() s390/sysinfo: show partition extended name and UUID if available s390/numa: pin all possible cpus to nodes early s390/numa: establish cpu to node mapping early s390/topology: use cpu_topology array instead of per cpu variable s390/smp: initialize cpu_present_mask in setup_arch s390/topology: always use s390 specific sched_domain_topology_level s390/smp: use smp_get_base_cpu() helper function s390/numa: always use logical cpu and core ids s390: Remove VLAIS in ptff() and clear_table() s390: fix machine check panic stack switch ...
| * s390/smp: initialize cpu_present_mask in setup_archHeiko Carstens2016-12-071-13/+9Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | In order to be able to setup the cpu to node mappings early it is a prerequisite to know which cpus are present. Therefore cpus must be detected much earlier than before. For sclp based cpu detection this requires yet another early sclp call, since the system is not ready to use the regular interrupt and memory allocations. Reviewed-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| * s390/smp: use smp_get_base_cpu() helper functionHeiko Carstens2016-12-071-2/+2
| | | | | | | | | | Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| * s390: move cputime accounting fields from thread_info to thread_structMartin Schwidefsky2016-11-111-3/+2Star
| | | | | | | | | | | | | | | | | | | | The user_timer and system_timer fields are used for the per-thread cputime accounting code. The access to these values is simpler if they are moved to the thread_struct as the task_thread_info(tsk) indirection is not needed anymore. Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| * s390: move thread_info into task_structHeiko Carstens2016-11-111-1/+0Star
| | | | | | | | | | | | | | | | This is the s390 variant of commit 15f4eae70d36 ("x86: Move thread_info into task_struct"). Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* | Merge branch 'smp-hotplug-for-linus' of ↵Linus Torvalds2016-12-131-25/+11Star
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull smp hotplug updates from Thomas Gleixner: "This is the final round of converting the notifier mess to the state machine. The removal of the notifiers and the related infrastructure will happen around rc1, as there are conversions outstanding in other trees. The whole exercise removed about 2000 lines of code in total and in course of the conversion several dozen bugs got fixed. The new mechanism allows to test almost every hotplug step standalone, so usage sites can exercise all transitions extensively. There is more room for improvement, like integrating all the pointlessly different architecture mechanisms of synchronizing, setting cpus online etc into the core code" * 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (60 commits) tracing/rb: Init the CPU mask on allocation soc/fsl/qbman: Convert to hotplug state machine soc/fsl/qbman: Convert to hotplug state machine zram: Convert to hotplug state machine KVM/PPC/Book3S HV: Convert to hotplug state machine arm64/cpuinfo: Convert to hotplug state machine arm64/cpuinfo: Make hotplug notifier symmetric mm/compaction: Convert to hotplug state machine iommu/vt-d: Convert to hotplug state machine mm/zswap: Convert pool to hotplug state machine mm/zswap: Convert dst-mem to hotplug state machine mm/zsmalloc: Convert to hotplug state machine mm/vmstat: Convert to hotplug state machine mm/vmstat: Avoid on each online CPU loops mm/vmstat: Drop get_online_cpus() from init_cpu_node_state/vmstat_cpu_dead() tracing/rb: Convert to hotplug state machine oprofile/nmi timer: Convert to hotplug state machine net/iucv: Use explicit clean up labels in iucv_init() x86/pci/amd-bus: Convert to hotplug state machine x86/oprofile/nmi: Convert to hotplug state machine ...
| * | s390/smp: Convert to hotplug state machineSebastian Andrzej Siewior2016-11-091-26/+11Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | cpuhp_setup_state() invokes the startup callback on all online cpus with the proper protection, so we can remove the cpu hotplug protection from the init function and the creation of the per cpu files for online cpus in smp_add_present_cpu(). smp_add_present_cpu() is called also called from __smp_rescan_cpus(), but this callpath never adds an online cpu, it merily adds newly present cpus, so the creation of the cpu files is not required. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: linux-s390@vger.kernel.org Cc: rt@linutronix.de Link: http://lkml.kernel.org/r/20161104144502.7kd4bxz2rxqvtack@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | s390/smp: Make cpu notifier symetricThomas Gleixner2016-11-091-1/+2
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There is no reason to remove the sysfs cpu files when the CPU is dead, they can be removed when the cpu is prepared to go down. Doing it at DOWN_PREPARE allows us to convert it to a symetric hotplug state in the next step. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: linux-s390@vger.kernel.org Cc: rt@linutronix.de Link: http://lkml.kernel.org/r/20161104144140.lcee6kwmwlx37m7g@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* / locking/spinlocks, s390: Implement vcpu_is_preempted(cpu)Christian Borntraeger2016-11-221-2/+7
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This implements the s390 version for vcpu_is_preempted(cpu), by reworking the existing smp_vcpu_scheduled() function into arch_vcpu_is_preempted(). We can then also get rid of the local cpu_is_preempted() function by moving the CIF_ENABLED_WAIT test into arch_vcpu_is_preempted(). Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: David.Laight@ACULAB.COM Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: benh@kernel.crashing.org Cc: boqun.feng@gmail.com Cc: bsingharora@gmail.com Cc: dave@stgolabs.net Cc: jgross@suse.com Cc: kernellwp@gmail.com Cc: konrad.wilk@oracle.com Cc: linuxppc-dev@lists.ozlabs.org Cc: mpe@ellerman.id.au Cc: paulmck@linux.vnet.ibm.com Cc: paulus@samba.org Cc: pbonzini@redhat.com Cc: rkrcmar@redhat.com Cc: virtualization@lists.linux-foundation.org Cc: will.deacon@arm.com Cc: xen-devel-request@lists.xenproject.org Cc: xen-devel@lists.xenproject.org Link: http://lkml.kernel.org/r/1478077718-37424-6-git-send-email-xinhui.pan@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* s390/smp: clean up a conditionDan Carpenter2016-07-181-1/+1
| | | | | | | | I can never remember precedence rules. Let's add some parenthesis so this code is more clear. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/smp: use basic blocks for sigp inline assembliesHeiko Carstens2016-06-281-7/+1Star
| | | | | | | | | | | Use only simple inline assemblies which consist of a single basic block if the register asm construct is being used. Otherwise gcc would generate broken code if the compiler option --sanitize-coverage=trace-pc would be used. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/mm: simplify the TLB flushing codeMartin Schwidefsky2016-06-131-6/+2Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | ptep_flush_lazy and pmdp_flush_lazy use mm->context.attach_count to decide between a lazy TLB flush vs an immediate TLB flush. The field contains two 16-bit counters, the number of CPUs that have the mm attached and can create TLB entries for it and the number of CPUs in the middle of a page table update. The __tlb_flush_asce, ptep_flush_direct and pmdp_flush_direct functions use the attach counter and a mask check with mm_cpumask(mm) to decide between a local flush local of the current CPU and a global flush. For all these functions the decision between lazy vs immediate and local vs global TLB flush can be based on CPU masks. There are two masks: the mm->context.cpu_attach_mask with the CPUs that are actively using the mm, and the mm_cpumask(mm) with the CPUs that have used the mm since the last full flush. The decision between lazy vs immediate flush is based on the mm->context.cpu_attach_mask, to decide between local vs global flush the mm_cpumask(mm) is used. With this patch all checks will use the CPU masks, the old counter mm->context.attach_count with its two 16-bit values is turned into a single counter mm->context.flush_count that keeps track of the number of CPUs with incomplete page table updates. The sole user of this counter is finish_arch_post_lock_switch() which waits for the end of all page table updates. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* sched: Allow per-cpu kernel threads to run on online && !activePeter Zijlstra (Intel)2016-05-061-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | In order to enable symmetric hotplug, we must mirror the online && !active state of cpu-down on the cpu-up side. However, to retain sanity, limit this state to per-cpu kthreads. Aside from the change to set_cpus_allowed_ptr(), which allow moving the per-cpu kthreads on, the other critical piece is the cpu selection for pinned tasks in select_task_rq(). This avoids dropping into select_fallback_rq(). select_fallback_rq() cannot be allowed to select !active cpus because its used to migrate user tasks away. And we do not want to move user tasks onto cpus that are in transition. Requested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Thomas Gleixner <tglx@linutronix.de> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: Jan H. Schönherr <jschoenh@amazon.de> Cc: Oleg Nesterov <oleg@redhat.com> Cc: rt@linutronix.de Link: http://lkml.kernel.org/r/20160301152303.GV6356@twins.programming.kicks-ass.net Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* arch/hotplug: Call into idle with a proper stateThomas Gleixner2016-03-011-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | Let the non boot cpus call into idle with the corresponding hotplug state, so the hotplug core can handle the further bringup. That's a first step to convert the boot side of the hotplugged cpus to do all the synchronization with the other side through the state machine. For now it'll only start the hotplug thread and kick the full bringup of the cpu. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: linux-arch@vger.kernel.org Cc: Rik van Riel <riel@redhat.com> Cc: Rafael Wysocki <rafael.j.wysocki@intel.com> Cc: "Srivatsa S. Bhat" <srivatsa@mit.edu> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Sebastian Siewior <bigeasy@linutronix.de> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Tejun Heo <tj@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Paul McKenney <paulmck@linux.vnet.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul Turner <pjt@google.com> Link: http://lkml.kernel.org/r/20160226182341.614102639@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* s390: remove superfluous memblock_alloc() return value checksHeiko Carstens2016-01-191-2/+0Star
| | | | | | | | | memblock_alloc() and memblock_alloc_base() will panic on their own if they can't find free memory. Therefore remove some pointless checks. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Acked-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390: rename struct _lowcore to struct lowcoreHeiko Carstens2016-01-111-8/+8
| | | | | | | | | | | | | Finally get rid of the leading underscore. I tried this already two or three years ago, however Michael Holzheu objected since this would break the crash utility (again). However Michael integrated support for the new name into the crash utility back then, so it doesn't break if the name will be changed now. So finally get rid of the ever confusing leading underscore. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/smp: save timestamp on external callsHeiko Carstens2015-12-181-0/+2
| | | | | | | | | | | | This is supposed to make debugging easier: if within a dump we can see that an external call or emergency signal IPI is pending but all cpus are idle, we have no idea for how long the interrupt is outstanding. Therefore save a timestamp into the per cpu pcpu array of the target cpu whenever such an IPI is sent. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/dump: cleanup CPU save area handlingMartin Schwidefsky2015-11-271-23/+14Star
| | | | | | | | | | | Introduce save_area_alloc(), save_area_boot_cpu(), save_area_add_regs() and save_area_add_vxrs to deal with storing the CPU state in case of a system dump. Remove struct save_area and save_area_ext, and create a new struct save_area as a local definition to arch/s390/kernel/crash_dump.c. Copy each individual field from the hardware status area to the save area, storing the minimum of required data. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/dump: rework CPU register dump codeMartin Schwidefsky2015-11-271-51/+61
| | | | | | | | | | | | | | | | To collect the CPU registers of the crashed system allocated a single page with memblock_alloc_base and use it as a copy buffer. Replace the stop-and-store-status sigp with a store-status-at-address sigp in smp_save_dump_cpus() and smp_store_status(). In both cases the target CPU is already stopped and store-status-at-address avoids the detour via the absolute zero page. For kexec simplify s390_reset_system and call store_status() before the prefix register of the boot CPU has been set to zero. Use STPX to store the prefix register and remove dump_prefix_page. Acked-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/dump: remove SAVE_AREA_BASEMartin Schwidefsky2015-11-271-2/+2
| | | | | | | | | | | Replace the SAVE_AREA_BASE offset calculations in reipl.S with the assembler constant for the location of each register status area. Use __LC_FPREGS_SAVE_AREA instead of SAVE_AREA_BASE in the three remaining code locations and remove the definition of SAVE_AREA_BASE. Acked-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/dump: streamline oldmem copy functionsMartin Schwidefsky2015-11-271-2/+2
| | | | | | | | | Introduce two copy functions for the memory of the dumped system, copy_oldmem_kernel() to copy to the virtual kernel address space and copy_oldmem_user() to copy to user space. Acked-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/kdump: remove code to create ELF notes in the crashed systemMartin Schwidefsky2015-11-271-6/+2Star
| | | | | | | | | | The s390 architecture can store the CPU registers of the crashed system after the kdump kernel has been started and this is the preferred way. Remove the remaining code fragments that deal with storing CPU registers while the crashed system is still active. Acked-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/cpumf: rework program parameter setting to detect guest samplesChristian Borntraeger2015-10-141-0/+2
| | | | | | | | | | | | | | | | | | | | | | The program parameter can be used to mark hardware samples with some token. Previously, it was used to mark guest samples only. Improve the program parameter doubleword by combining two parts, the leftmost LPP part and the rightmost PID part. Set the PID part for processes by using the task PID. To distinguish host and guest samples for the kernel (PID part is zero), the guest must always set the program paramater to a non-zero value. Use the leftmost bit in the LPP part of the program parameter to be able to detect guest kernel samples. [brueckner@linux.vnet.ibm.com]: Split __LC_CURRENT and introduced __LC_LPP. Corrected __LC_CURRENT users and adjusted assembler parts. And updated the commit message accordingly. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com> Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/diag: add tracepoint for diagnose callsMartin Schwidefsky2015-10-141-2/+2
| | | | | | | | | | | To be able to analyse problems in regard to hypervisor overhead add a tracepoing for diagnose calls. It reports the number of the diagnose issued, e.g. sshd-1385 [002] .... 42.701431: diagnose: nr=0x9c <idle>-0 [001] ..s. 43.587528: diagnose: nr=0x9c Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/diag: add a statistic for diagnose callsMartin Schwidefsky2015-10-141-2/+6
| | | | | | | 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 <schwidefsky@de.ibm.com>
* s390/smp: add missing __init annotation to __smp_store_cpu_state()Heiko Carstens2015-07-291-2/+2
| | | | | | | | | | | Section mismatch in reference from the function __smp_store_cpu_state() to the function .init.text:memblock_alloc() The function __smp_store_cpu_state() references the function __init memblock_alloc(). Reviewed-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/kdump: fix compile for !SMPHeiko Carstens2015-06-291-23/+21Star
| | | | | | | | | | Fix this compile error: arch/s390/kernel/setup.c:875:2: error: implicit declaration of function 'smp_save_dump_cpus' Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/kdump: fix nosmt kernel parameterMichael Holzheu2015-06-251-30/+40
| | | | | | | | | | | | | | | | | | | | | It turned out that SIGP set-multi-threading can only be done once. Therefore switching to a different MT level after switching to sclp.mtid_prev in the dump case fails. As a symptom specifying the "nosmt" parameter currently fails for the kdump kernel and the kernel starts with multi-threading enabled. So fix this and issue diag 308 subcode 1 call after collecting the CPU states for the dump. Also enhance the diag308_reset() function to be usable also with enabled lowcore protection and prefix register != 0. After the reset it is possible to switch the MT level again. We have to do the reset very early in order not to kill the already initialized console. Therefore instead of kmalloc() the corresponding memblock functions have to be used. To avoid copying the sclp cpu code into sclp_early, we now use the simple sigp loop method for CPU detection. Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/smp: cleanup core vs. cpu in the SCLP interfaceMartin Schwidefsky2015-06-251-24/+25
| | | | | | | | | | | | | | The SCLP interface to query, configure and deconfigure CPUs actually operates on cores. For a machine without the multi-threading faciltiy a CPU and a core are equivalent but starting with System z13 a core can have multiple hardware threads, also referred to as logical CPUs. To avoid confusion replace the word 'cpu' with 'core' in the SCLP interface. Also replace MAX_CPU_ADDRESS with SCLP_MAX_CORES. The core-id is an 8-bit field, the maximum thread id is in the range 0-31. The theoretical limit for the CPU address is therefore 8191. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/smp: fix sigp cpu detection loopMartin Schwidefsky2015-06-251-1/+2
| | | | | | | | | On a (theoretical) system where the read-cpu-info SCLP command does not work but SMT is enabled, the sigp detection loop may not find all configured cores. The maximum CPU address needs to be shifted with smp_cpu_mt_shift. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/sclp: get rid of sclp_get_mtid() and sclp_get_mtid_max()David Hildenbrand2015-05-131-2/+3
| | | | | | | | | As all relevant sclp data is now directly accessible, let's move the logic of these two functions to the single caller. Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/sclp: unify basic sclp access by exposing "struct sclp"David Hildenbrand2015-05-131-2/+2
| | | | | | | | | | | | | | Let's unify basic access to sclp fields by storing the data in an external struct in asm/sclp.h. The values can now directly be accessed by other components, so there is no need for most accessor functions and external variables anymore. The mtid, mtid_max and facility part will be cleaned up separately. Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/sclp: prepare smp_fill_possible_mask for global "struct sclp"David Hildenbrand2015-05-131-4/+4
| | | | | | | | | We need to rename sclp -> sclp_max to prepare for using the global variable "sclp" for sclp access later in this function. Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/smp: wait until secondaries are active & onlineHeiko Carstens2015-04-131-1/+2
| | | | | | | | | | This is the s390 version of 875ebe940d77 ("powerpc/smp: Wait until secondaries are active & online"). The race described in length within the commit message is also possible on s390 and every other architecture. So fix this race on s390 as well. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390: remove 31 bit supportHeiko Carstens2015-03-251-33/+0Star
| | | | | | | | | | | | | | | | | | | Remove the 31 bit support in order to reduce maintenance cost and effectively remove dead code. Since a couple of years there is no distribution left that comes with a 31 bit kernel. The 31 bit kernel also has been broken since more than a year before anybody noticed. In addition I added a removal warning to the kernel shown at ipl for 5 minutes: a960062e5826 ("s390: add 31 bit warning message") which let everybody know about the plan to remove 31 bit code. We didn't get any response. Given that the last 31 bit only machine was introduced in 1999 let's remove the code. Anybody with 31 bit user space code can still use the compat mode. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/smp: reduce size of struct pcpuHeiko Carstens2015-02-121-27/+27
| | | | | | | | | | | Reduce the size of struct pcpu, since the pcpu_devices array consists of NR_CPUS elements of type struct pcpu. For most machines this is just a waste of memory. So let's try to make it a bit smaller. This saves 16k with performance_defconfig. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/smp: remove check for CONFIG_ZFCPDUMPPaul Bolle2015-01-221-1/+1
| | | | | | | | | | | | | | | Commit 725908110a1f ("s390: add SMT support") added a check for CONFIG_ZFCPDUMP. But the Kconfig symbol ZFCPDUMP was removed in v3.16 through commit bf28a5970de3 ("s390/dump: Remove CONFIG_ZFCPDUMP"). So this check will always evaluate to false. No one noticed probably because the code also checks for CONFIG_CRASH_DUMP which "also enables s390 zfcpdump". Dump the unneeded check. Signed-off-by: Paul Bolle <pebolle@tiscali.nl> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390: add SMT supportMartin Schwidefsky2015-01-221-56/+205
| | | | | | | | | | | | | | | | | | | | The multi-threading facility is introduced with the z13 processor family. This patch adds code to detect the multi-threading facility. With the facility enabled each core will surface multiple hardware threads to the system. Each hardware threads looks like a normal CPU to the operating system with all its registers and properties. The SCLP interface reports the SMT topology indirectly via the maximum thread id. Each reported CPU in the result of a read-scp-information is a core representing a number of hardware threads. To reflect the reduced CPU capacity if two hardware threads run on a single core the MT utilization counter set is used to normalize the raw cputime obtained by the CPU timer deltas. This scaled cputime is reported via the taskstats interface. The normal /proc/stat numbers are based on the raw cputime and are not affected by the normalization. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/ftrace,kprobes: allow to patch first instructionHeiko Carstens2014-10-271-1/+0Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If the function tracer is enabled, allow to set kprobes on the first instruction of a function (which is the function trace caller): If no kprobe is set handling of enabling and disabling function tracing of a function simply patches the first instruction. Either it is a nop (right now it's an unconditional branch, which skips the mcount block), or it's a branch to the ftrace_caller() function. If a kprobe is being placed on a function tracer calling instruction we encode if we actually have a nop or branch in the remaining bytes after the breakpoint instruction (illegal opcode). This is possible, since the size of the instruction used for the nop and branch is six bytes, while the size of the breakpoint is only two bytes. Therefore the first two bytes contain the illegal opcode and the last four bytes contain either "0" for nop or "1" for branch. The kprobes code will then execute/simulate the correct instruction. Instruction patching for kprobes and function tracer is always done with stop_machine(). Therefore we don't have any races where an instruction is patched concurrently on a different cpu. Besides that also the program check handler which executes the function trace caller instruction won't be executed concurrently to any stop_machine() execution. This allows to keep full fault based kprobes handling which generates correct pt_regs contents automatically. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/kdump: add support for vector extensionMichael Holzheu2014-10-091-6/+25
| | | | | | | | | | | | | | | | | | | | | | | | | | With this patch for kdump the s390 vector registers are stored into the prepared save areas in the old kernel and into the REGSET_VX_LOW and REGSET_VX_HIGH ELF notes for /proc/vmcore in the new kernel. The NT_S390_VXRS_LOW note contains the lower halves of the first 16 vector registers 0-15. The higher halves are stored in the floating point register ELF note. The NT_S390_VXRS_HIGH contains the full vector registers 16-31. The kernel provides a save area for storing vector register in case of machine checks. A pointer to this save are is stored in the CPU lowcore at offset 0x11b0. This save area is also used to save the registers for kdump. In case of a dumped crashed kdump those areas are used to extract the registers of the production system. The vector registers for remote CPUs are stored using the "store additional status at address" SIGP. For the dump CPU the vector registers are stored with the VSTM instruction. With this patch also zfcpdump stores the vector registers. Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390: add support for vector extensionMartin Schwidefsky2014-10-091-0/+3
| | | | | | | | | | | | | | The vector extension introduces 32 128-bit vector registers and a set of instruction to operate on the vector registers. The kernel can control the use of vector registers for the problem state program with a bit in control register 0. Once enabled for a process the kernel needs to retain the content of the vector registers on context switch. The signal frame is extended to include the vector registers. Two new register sets NT_S390_VXRS_LOW and NT_S390_VXRS_HIGH are added to the regset interface for the debugger and core dumps. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/idle: consolidate idle functions and definitionsMartin Schwidefsky2014-10-091-37/+2Star
| | | | | | | | | Move the C functions and definitions related to the idle state handling to arch/s390/include/asm/idle.h and arch/s390/kernel/idle.c. The function s390_get_idle_time is renamed to arch_cpu_idle_time and vtime_stop_cpu to enabled_wait. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>