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* s390/smp: wait until secondaries are active & onlineHeiko Carstens2015-04-13
| | | | | | | | | | 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 Carstens2015-03-25
| | | | | | | | | | | | | | | | | | | 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 Carstens2015-02-12
| | | | | | | | | | | 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 Bolle2015-01-22
| | | | | | | | | | | | | | | 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 Schwidefsky2015-01-22
| | | | | | | | | | | | | | | | | | | | 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 Carstens2014-10-27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 Holzheu2014-10-09
| | | | | | | | | | | | | | | | | | | | | | | | | | 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 Schwidefsky2014-10-09
| | | | | | | | | | | | | | 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 Schwidefsky2014-10-09
| | | | | | | | | 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>
* s390/nohz: use a per-cpu flag for arch_needs_cpuMartin Schwidefsky2014-10-09
| | | | | | | | Move the nohz_delay bit from the s390_idle data structure to the per-cpu flags. Clear the nohz delay flag in __cpu_disable and remove the cpu hotplug notifier that used to do this. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/rwlock: use directed yield for write-locked rwlocksMartin Schwidefsky2014-09-25
| | | | | | | | | Add an owner field to the arch_rwlock_t to be able to pass the timeslice of a virtual CPU with diagnose 0x9c to the lock owner in case the rwlock is write-locked. The undirected yield in case the rwlock is acquired writable but the lock is read-locked is removed. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/smp: Avoid busy loop after halt and "begin" on z/VMMichael Holzheu2014-05-20
| | | | | | | | | | | Currently the smp_stop_cpu() function for SMP kernels enters a busy loop when "begin" is entered on the z/VM console after Linux is halted. To avoid this behavior, use the non-SMP variant of smp_stop_cpu() which stops the CPU again after "begin" is entered. As a side effect we now have consistent behavior for SMP and non-SMP Linux. Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/dump: Remove CONFIG_ZFCPDUMPMichael Holzheu2014-05-20
| | | | | | | | | | | Currently there are two s390 kernel dump config options "CONFIG_ZFCPDUMP" and "CONFIG_CRASH_DUMP". In order to keep things simple and because the "CONFIG_ZFCPDUMP" option already has a dependency to "CONFIG_CRASH_DUMP" remove the CONFIG_ZFCPDUMP option. Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Reviewed-by: Eric Farman <farman@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/spinlock: optimize spinlock code sequencePhilipp Hachtmann2014-05-20
| | | | | | | | | Use lowcore constant to improve the code generated for spinlocks. [ Martin Schwidefsky: patch breakdown and code beautification ] Signed-off-by: Philipp Hachtmann <phacht@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/smp: fix smp_stop_cpu() for !CONFIG_SMPHeiko Carstens2014-04-09
| | | | | | | | | | | | | | | | | | | | | | smp_stop_cpu() should stop the current cpu even for !CONFIG_SMP. Otherwise machine_halt() will return and and the machine generates a panic instread of simply stopping the current cpu: Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000000 CPU: 0 PID: 1 Comm: systemd-shutdow Not tainted 3.14.0-01527-g2b6ef16a6bc5 #10 [...] Call Trace: ([<0000000000110db0>] show_trace+0xf8/0x158) [<0000000000110e7a>] show_stack+0x6a/0xe8 [<000000000074dba8>] panic+0xe4/0x268 [<0000000000140570>] do_exit+0xa88/0xb2c [<000000000016e12c>] SyS_reboot+0x1f0/0x234 [<000000000075da70>] sysc_nr_ok+0x22/0x28 [<000000007d5a09b4>] 0x7d5a09b4 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 Torvalds2014-04-08
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull second set of s390 patches from Martin Schwidefsky: "The second part of Heikos uaccess rework, the page table walker for uaccess is now a thing of the past (yay!) The code change to fix the theoretical TLB flush problem allows us to add a TLB flush optimization for zEC12, this machine has new instructions that allow to do CPU local TLB flushes for single pages and for all pages of a specific address space. Plus the usual bug fixing and some more cleanup" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: s390/uaccess: rework uaccess code - fix locking issues s390/mm,tlb: optimize TLB flushing for zEC12 s390/mm,tlb: safeguard against speculative TLB creation s390/irq: Use defines for external interruption codes s390/irq: Add defines for external interruption codes s390/sclp: add timeout for queued requests kvm/s390: also set guest pages back to stable on kexec/kdump lcs: Add missing destroy_timer_on_stack() s390/tape: Add missing destroy_timer_on_stack() s390/tape: Use del_timer_sync() s390/3270: fix crash with multiple reset device requests s390/bitops,atomic: add missing memory barriers s390/zcrypt: add length check for aligned data to avoid overflow in msg-type 6
| * s390/mm,tlb: optimize TLB flushing for zEC12Martin Schwidefsky2014-04-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The zEC12 machines introduced the local-clearing control for the IDTE and IPTE instruction. If the control is set only the TLB of the local CPU is cleared of entries, either all entries of a single address space for IDTE, or the entry for a single page-table entry for IPTE. Without the local-clearing control the TLB flush is broadcasted to all CPUs in the configuration, which is expensive. The reset of the bit mask of the CPUs that need flushing after a non-local IDTE is tricky. As TLB entries for an address space remain in the TLB even if the address space is detached a new bit field is required to keep track of attached CPUs vs. CPUs in the need of a flush. After a non-local flush with IDTE the bit-field of attached CPUs is copied to the bit-field of CPUs in need of a flush. The ordering of operations on cpu_attach_mask, attach_count and mm_cpumask(mm) is such that an underindication in mm_cpumask(mm) is prevented but an overindication in mm_cpumask(mm) is possible. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| * s390/irq: Use defines for external interruption codesThomas Huth2014-04-03
| | | | | | | | | | | | | | | | | | | | | | Use the new defines for external interruption codes to get rid of "magic" numbers in the s390 source code. And while we're at it, also rename the (un-)register_external_interrupt function to something shorter so that this patch does not exceed the 80 columns all over the place. Signed-off-by: Thomas Huth <thuth@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* | Merge tag 'cpu-hotplug-3.15-rc1' of ↵Linus Torvalds2014-04-07
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull CPU hotplug notifiers registration fixes from Rafael Wysocki: "The purpose of this single series of commits from Srivatsa S Bhat (with a small piece from Gautham R Shenoy) touching multiple subsystems that use CPU hotplug notifiers is to provide a way to register them that will not lead to deadlocks with CPU online/offline operations as described in the changelog of commit 93ae4f978ca7f ("CPU hotplug: Provide lockless versions of callback registration functions"). The first three commits in the series introduce the API and document it and the rest simply goes through the users of CPU hotplug notifiers and converts them to using the new method" * tag 'cpu-hotplug-3.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (52 commits) net/iucv/iucv.c: Fix CPU hotplug callback registration net/core/flow.c: Fix CPU hotplug callback registration mm, zswap: Fix CPU hotplug callback registration mm, vmstat: Fix CPU hotplug callback registration profile: Fix CPU hotplug callback registration trace, ring-buffer: Fix CPU hotplug callback registration xen, balloon: Fix CPU hotplug callback registration hwmon, via-cputemp: Fix CPU hotplug callback registration hwmon, coretemp: Fix CPU hotplug callback registration thermal, x86-pkg-temp: Fix CPU hotplug callback registration octeon, watchdog: Fix CPU hotplug callback registration oprofile, nmi-timer: Fix CPU hotplug callback registration intel-idle: Fix CPU hotplug callback registration clocksource, dummy-timer: Fix CPU hotplug callback registration drivers/base/topology.c: Fix CPU hotplug callback registration acpi-cpufreq: Fix CPU hotplug callback registration zsmalloc: Fix CPU hotplug callback registration scsi, fcoe: Fix CPU hotplug callback registration scsi, bnx2fc: Fix CPU hotplug callback registration scsi, bnx2i: Fix CPU hotplug callback registration ...
| * s390, smp: Fix CPU hotplug callback registrationSrivatsa S. Bhat2014-03-20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Subsystems that want to register CPU hotplug callbacks, as well as perform initialization for the CPUs that are already online, often do it as shown below: get_online_cpus(); for_each_online_cpu(cpu) init_cpu(cpu); register_cpu_notifier(&foobar_cpu_notifier); put_online_cpus(); This is wrong, since it is prone to ABBA deadlocks involving the cpu_add_remove_lock and the cpu_hotplug.lock (when running concurrently with CPU hotplug operations). Instead, the correct and race-free way of performing the callback registration is: cpu_notifier_register_begin(); for_each_online_cpu(cpu) init_cpu(cpu); /* Note the use of the double underscored version of the API */ __register_cpu_notifier(&foobar_cpu_notifier); cpu_notifier_register_done(); Fix the smp code in s390 by using this latter form of callback registration. Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@kernel.org> Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* | s390/smp: limit number of cpus in possible cpu maskHeiko Carstens2014-03-17
|/ | | | | | | | | | | | Limit the number of bits to the maximum number of cpus a machine can have. possible_cpu_mask typically will have more bits set than a machine may physically have. This results in wasted memory during per-cpu memory allocations, if the possible mask contains more cpus than physically possible for a given configuration. 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 Torvalds2014-01-20
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 updates from Martin Schwidefsky: "The bulk of the s390 updates for v3.14. New features are the perf support for the CPU-Measurement Sample Facility and the EP11 support for the crypto cards. And the normal cleanups and bug-fixes" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (44 commits) s390/cpum_sf: fix printk format warnings s390: Fix misspellings using 'codespell' tool s390/qdio: bridgeport support - CHSC part s390: delete new instances of __cpuinit usage s390/compat: fix PSW32_USER_BITS definition s390/zcrypt: add support for EP11 coprocessor cards s390/mm: optimize randomize_et_dyn for !PF_RANDOMIZE s390: use IS_ENABLED to check if a CONFIG is set to y or m s390/cio: use device_lock to synchronize calls to the ccwgroup driver s390/cio: use device_lock to synchronize calls to the ccw driver s390/cio: fix unlocked access of online member s390/cpum_sf: Add flag to process full SDBs only s390/cpum_sf: Add raw data sampling to support the diagnostic-sampling function s390/cpum_sf: Filter perf events based event->attr.exclude_* settings s390/cpum_sf: Detect KVM guest samples s390/cpum_sf: Add helper to read TOD from trailer entries s390/cpum_sf: Atomically reset trailer entry fields of sample-data-blocks s390/cpum_sf: Dynamically extend the sampling buffer if overflows occur s390/pci: reenable per default s390/pci/dma: fix accounting of allocated_pages ...
| * s390/smp: reduce memory consumption of pcpu_devices arrayHeiko Carstens2013-12-16
| | | | | | | | | | | | | | | | | | | | | | | | Remove the embedded struct cpu from struct pcpu and replace it with a pointer instead. The struct cpu now gets allocated when a new cpu gets detected. The size of the pcpu_devices array (NR_CPUS * sizeof(struct pcpu)) gets reduced by nearly 120KB. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| * s390/smp: only send external call ipi if neededHeiko Carstens2013-12-16
| | | | | | | | | | | | | | | | | | If the per cpu ec_mask bit of the receiving cpu is already set there is no need to send an ipi, since a different cpu has already sent an ipi and the receiving cpu has not yet executed the external call ipi handler. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* | s390/smp: improve setup of possible cpu maskHeiko Carstens2013-12-18
|/ | | | | | | | | | Since under z/VM we cannot have more than 64 cpus, make sure the cpu_possible_mask does not contain more bits. This avoids wasting memory for dynamic per-cpu allocations if CONFIG_NR_CPUS is larger than 64. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/vtime: correct idle time calculationMartin Schwidefsky2013-10-31
| | | | | | | | | | Use the ACCESS_ONCE macro for both accesses to idle->sequence in the loops to calculate the idle time. If only one access uses the macro, the compiler is free to cache the value for the second access which can cause endless loops. Cc: stable@vger.kernel.org # 3.6+ Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390: Remove zfcpdump NR_CPUS dependencyMichael Holzheu2013-10-24
| | | | | | | | | | Currently zfpcdump can only collect registers for up to CONFIG_NR_CPUS CPUss. This dependency is not necessary. So remove it by dynamically allocating the save area array. Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/uaccess: always run the kernel in home spaceMartin Schwidefsky2013-10-24
| | | | | | | Simplify the uaccess code by removing the user_mode=home option. The kernel will now always run in the home space mode. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390: make various functions static, add declarations to header filesHeiko Carstens2013-09-07
| | | | | | | Make various functions static, add declarations to header files to fix a couple of sparse findings. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
* s390: delete __cpuinit usage from all s390 filesPaul Gortmaker2013-07-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The __cpuinit type of throwaway sections might have made sense some time ago when RAM was more constrained, but now the savings do not offset the cost and complications. For example, the fix in commit 5e427ec2d0 ("x86: Fix bit corruption at CPU resume time") is a good example of the nasty type of bugs that can be created with improper use of the various __init prefixes. After a discussion on LKML[1] it was decided that cpuinit should go the way of devinit and be phased out. Once all the users are gone, we can then finally remove the macros themselves from linux/init.h. Note that some harmless section mismatch warnings may result, since notify_cpu_starting() and cpu_up() are arch independent (kernel/cpu.c) are flagged as __cpuinit -- so if we remove the __cpuinit from arch specific callers, we will also get section mismatch warnings. As an intermediate step, we intend to turn the linux/init.h cpuinit content into no-ops as early as possible, since that will get rid of these warnings. In any case, they are temporary and harmless. This removes all the arch/s390 uses of the __cpuinit macros from all C files. Currently s390 does not have any __CPUINIT used in assembly files. [1] https://lkml.org/lkml/2013/5/20/589 Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: linux390@de.ibm.com Cc: linux-s390@vger.kernel.org Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* s390/smp: get rid of generic_smp_call_function_interruptHeiko Carstens2013-06-26
| | | | | | | | | | | Since 9a46ad6d6 "smp: make smp_call_function_many() use logic similar to smp_call_function_single()" generic_smp_call_function_interrupt() is only an alias to generic_smp_call_function_single_interrupt(). So remove the superfluous variant. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/smp: lost IPIs on cpu hotplugHeiko Carstens2013-05-27
| | | | | | | | | | | | | | | | | | | | | | | IPIs might be lost when a cpu gets brought offline: When stop_machine executes its state machine there is a race window for the state STOPMACHINE_DISABLE_IRQ where the to be brought offline cpu might already have irqs disabled but a different cpu still may have irqs enabled. If the enabled cpu receives an interrupt and as a result sends an IPI to the to be offlined cpu in its bottom halve context, the IPI won't be noticed before the cpu is offline. In fact the race window is much larger since there is no guarantee when an IPI will be received. To fix this check for enqueued but not yet received IPIs in the cpu_disable() path and call the respective handlers before the cpu is marked offline. Reported-by: Juergen Doelle <juergen.doelle@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/smp: fix cpu re-scan vs. cpu stateMartin Schwidefsky2013-05-17
| | | | | | | | | | The cpu-info array starts with a list of cpus in configured state, followed by the cpus in standby state. The comparison to decide which state a cpu has is incorrect, this causes configured cpus appear as standby cpus. The correct comparison is the index of the new cpu in the cpu-info array vs. the number of configured cpus. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* Merge branch 'smp-hotplug-for-linus' of ↵Linus Torvalds2013-04-30
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull SMP/hotplug changes from Ingo Molnar: "This is a pretty large, multi-arch series unifying and generalizing the various disjunct pieces of idle routines that architectures have historically copied from each other and have grown in random, wildly inconsistent and sometimes buggy directions: 101 files changed, 455 insertions(+), 1328 deletions(-) this went through a number of review and test iterations before it was committed, it was tested on various architectures, was exposed to linux-next for quite some time - nevertheless it might cause problems on architectures that don't read the mailing lists and don't regularly test linux-next. This cat herding excercise was motivated by the -rt kernel, and was brought to you by Thomas "the Whip" Gleixner." * 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (40 commits) idle: Remove GENERIC_IDLE_LOOP config switch um: Use generic idle loop ia64: Make sure interrupts enabled when we "safe_halt()" sparc: Use generic idle loop idle: Remove unused ARCH_HAS_DEFAULT_IDLE bfin: Fix typo in arch_cpu_idle() xtensa: Use generic idle loop x86: Use generic idle loop unicore: Use generic idle loop tile: Use generic idle loop tile: Enter idle with preemption disabled sh: Use generic idle loop score: Use generic idle loop s390: Use generic idle loop powerpc: Use generic idle loop parisc: Use generic idle loop openrisc: Use generic idle loop mn10300: Use generic idle loop mips: Use generic idle loop microblaze: Use generic idle loop ...
| * s390: Use generic idle loopThomas Gleixner2013-04-08
| | | | | | | | | | | | | | | | | | | | | | | | | | Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Paul McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Reviewed-by: Cc: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Cc: Magnus Damm <magnus.damm@gmail.com> Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> Link: http://lkml.kernel.org/r/20130321215235.090816526@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* | s390: lowcore stack pointer offsetsMartin Schwidefsky2013-04-26
|/ | | | | | | | Store the stack pointers in the lowcore for the kernel stack, the async stack and the panic stack with the offset required for the first user. This avoids an unnecessary add instruction on the system call path. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/time: rename tod clock access functionsHeiko Carstens2013-02-14
| | | | | | | | Fix name clash with some common code device drivers and add "tod" to all tod clock access function names. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/irq: count cpu restart eventsHeiko Carstens2013-01-08
| | | | | | | | Count CPU Restart events and make them visible via /proc/interrupts. Every CPU hotplug (online) event will increase the per cpu counter. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/irq: remove split irq fields from /proc/statHeiko Carstens2013-01-08
| | | | | | | | | | | | | | | | | | | | | Now that irq sum accounting for /proc/stat's "intr" line works again we have the oddity that the sum field (first field) contains only the sum of the second (external irqs) and third field (I/O interrupts). The reason for that is that these two fields are already sums of all other fields. So if we would sum up everything we would count every interrupt twice. This is broken since the split interrupt accounting was merged two years ago: 052ff461c8427629aee887ccc27478fc7373237c "[S390] irq: have detailed statistics for interrupt types". To fix this remove the split interrupt fields from /proc/stat's "intr" line again and only have them in /proc/interrupts. This restores the old behaviour, seems to be the only sane fix and mimics a behaviour from other architectures where /proc/interrupts also contains more than /proc/stat's "intr" line does. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/smp: fix section mismatch for smp_add_present_cpu()Heiko Carstens2013-01-08
| | | | | | | | | | | | | | Fixes this section mismatch: WARNING: vmlinux.o(.text+0x145e4): Section mismatch in reference from the function smp_add_present_cpu() to the function .cpuinit.text:register_cpu() The function smp_add_present_cpu() references the function __cpuinit register_cpu(). This is often because smp_add_present_cpu lacks a __cpuinit annotation or the annotation of register_cpu is wrong. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* ARCH: drivers remove __dev* attributes.Greg Kroah-Hartman2013-01-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This fixes up all of the smaller arches that had __dev* markings for their platform-specific drivers. CONFIG_HOTPLUG is going away as an option. As a result, the __dev* markings need to be removed. This change removes the use of __devinit, __devexit_p, __devinitdata, __devinitconst, and __devexit from these drivers. Based on patches originally written by Bill Pemberton, but redone by me in order to handle some of the coding style issues better, by hand. Cc: Bill Pemberton <wfp5p@virginia.edu> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Haavard Skinnemoen <hskinnemoen@gmail.com> Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no> Cc: Mike Frysinger <vapier@gentoo.org> Cc: Mikael Starvik <starvik@axis.com> Cc: Jesper Nilsson <jesper.nilsson@axis.com> Cc: David Howells <dhowells@redhat.com> Cc: Hirokazu Takata <takata@linux-m32r.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Michal Simek <monstr@monstr.eu> Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com> Cc: Jonas Bonn <jonas@southpole.se> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Helge Deller <deller@gmx.de> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Chen Liqin <liqin.chen@sunplusct.com> Cc: Lennox Wu <lennox.wu@gmail.com> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Guan Xuetao <gxt@mprc.pku.edu.cn> Cc: Bob Liu <lliubbo@gmail.com> Cc: Srinivas Kandagatla <srinivas.kandagatla@st.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Myron Stowe <myron.stowe@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andi Kleen <ak@linux.intel.com> Cc: Jesse Barnes <jbarnes@virtuousgeek.org> Cc: Sebastian Andrzej Siewior <sebastian@breakpoint.cc> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Thierry Reding <thierry.reding@avionic-design.de> Cc: Greg Ungerer <gerg@uclinux.org> Cc: Grant Likely <grant.likely@secretlab.ca> Cc: "Srivatsa S. Bhat" <srivatsa.bhat@linux.vnet.ibm.com> Cc: Mark Salter <msalter@redhat.com> Cc: Yong Zhang <yong.zhang0@gmail.com> Cc: Michael Holzheu <holzheu@linux.vnet.ibm.com> Cc: Cornelia Huck <cornelia.huck@de.ibm.com> Cc: Jan Glauber <jang@linux.vnet.ibm.com> Cc: Wei Yongjun <yongjun_wei@trendmicro.com.cn> Cc: Nobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* s390: add uninitialized_var() to suppress false positive compiler warningsHeiko Carstens2012-09-26
| | | | | | | | | | | | Get rid of these: arch/s390/kernel/smp.c:134:19: warning: ‘status’ may be used uninitialized in this function [-Wuninitialized] arch/s390/mm/pgtable.c:641:10: warning: ‘table’ may be used uninitialized in this function [-Wuninitialized] arch/s390/mm/pgtable.c:644:12: warning: ‘page’ may be used uninitialized in this function [-Wuninitialized] drivers/s390/cio/cio.c:1037:14: warning: ‘schid’ may be used uninitialized in this function [-Wuninitialized] Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/smp,topology: add polarization member to pcpu structHeiko Carstens2012-09-26
| | | | | | | | The cpu polarization member is the only per cpu state that is not part of the pcpu structure. So add it there and have everything in one place. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/smp: avoid concurrent write to sigp status fieldHeiko Carstens2012-09-26
| | | | | | | | | | | | | | | | | When a sigp instruction is issued it may store a status. This status is currently stored in a per cpu field of the target cpu. If multiple cpus issue a sigp instruction with the same target cpu and a status is stored the result is not necessarily as expected. Currently this is not an issue: - on cpu hotplug no sigps, except "restart" and "sense" are sent to the target cpu. - on external call we don't look at the status if it is stored - on sense running the condition code "status stored" is sufficient to tell if a cpu is running or not Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/cpu hotplug: mask out CPU_TASKS_FROZEN in cu hotplug notifiersHeiko Carstens2012-09-26
| | | | | | | | | Unify all our cpu hotplug notifiers to mask out the CPU_TASKS_FROZEN bit, so we don't have to add all the *_FROZEN variant cases to the notifiers. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/cpu hotplug: use hotcpu_notifier() instead of register_cpu_notifier()Heiko Carstens2012-09-26
| | | | | | | Saves a couple of lines of code. 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 Torvalds2012-07-24
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 changes from Martin Schwidefsky: "No new functions, a few changes to make the code more robust, some cleanups and bug fixes." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (21 commits) s390/vtimer: rework virtual timer interface s390/dis: Add the servc instruction to the disassembler. s390/comments: unify copyright messages and remove file names s390/lgr: Add init check to lgr_info_log() s390/cpu init: use __get_cpu_var instead of per_cpu s390/idle: reduce size of s390_idle_data structure s390/idle: fix sequence handling vs cpu hotplug s390/ap: resend enable adapter interrupt request. s390/hypfs: Add missing get_next_ino() s390/dasd: add shutdown action s390/ipl: Fix ipib handling for "dumpreipl" shutdown action s390/smp: make absolute lowcore / cpu restart parameter accesses more robust s390/vmlogrdr: cleanup driver attribute usage s390/vmlogrdr: cleanup device attribute usage s390/ccwgroup: remove unused ccwgroup_device member s390/cio/chp: cleanup attribute usage s390/sigp: use sigp order code defines in assembly code s390/smp: use sigp cpu status definitions s390/smp/kvm: unifiy sigp definitions s390/smp: remove redundant check ...
| * s390/vtimer: rework virtual timer interfaceMartin Schwidefsky2012-07-20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The current virtual timer interface is inherently per-cpu and hard to use. The sole user of the interface is appldata which uses it to execute a function after a specific amount of cputime has been used over all cpus. Rework the virtual timer interface to hook into the cputime accounting. This makes the interface independent from the CPU timer interrupts, and makes the virtual timers global as opposed to per-cpu. Overall the code is greatly simplified. The downside is that the accuracy is not as good as the original implementation, but it is still good enough for appldata. Reviewed-by: Jan Glauber <jang@linux.vnet.ibm.com> Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| * s390/comments: unify copyright messages and remove file namesHeiko Carstens2012-07-20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Remove the file name from the comment at top of many files. In most cases the file name was wrong anyway, so it's rather pointless. Also unify the IBM copyright statement. We did have a lot of sightly different statements and wanted to change them one after another whenever a file gets touched. However that never happened. Instead people start to take the old/"wrong" statements to use as a template for new files. So unify all of them in one go. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
| * s390/idle: fix sequence handling vs cpu hotplugHeiko Carstens2012-07-17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The s390 idle accounting code uses a sequence counter which gets used when the per cpu idle statistics get updated and read. One assumption on read access is that only when the sequence counter is even and did not change while reading all values the result is valid. On cpu hotplug however the per cpu data structure gets initialized via a cpu hotplug notifier on CPU_ONLINE. CPU_ONLINE however is too late, since the onlined cpu is already running and might access the per cpu data. Worst case is that the data structure gets initialized while an idle thread is updating its idle statistics. This will result in an uneven sequence counter after an update. As a result user space tools like top, which access /proc/stat in order to get idle stats, will busy loop waiting for the sequence counter to become even again, which will never happen until the queried cpu will update its idle statistics again. And even then the sequence counter will only have an even value for a couple of cpu cycles. Fix this by moving the initialization of the per cpu idle statistics to cpu_init(). I prefer that solution in favor of changing the notifier to CPU_UP_PREPARE, which would be a different solution to the problem. Cc: stable@vger.kernel.org Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>