kernel.git/arch/powerpc/platforms/pseries, branch linux-5.7.y

powerpc/pseries: Do not initiate shutdown when system is running on UPS

2020-08-26T09:42:23Z

commit 90a9b102eddf6a3f987d15f4454e26a2532c1c98 upstream. As per PAPR we have to look for both EPOW sensor value and event modifier to identify the type of event and take appropriate action. In LoPAPR v1.1 section 10.2.2 includes table 136 "EPOW Action Codes": SYSTEM_SHUTDOWN 3 The system must be shut down. An EPOW-aware OS logs the EPOW error log information, then schedules the system to be shut down to begin after an OS defined delay internal (default is 10 minutes.) Then in section 10.3.2.2.8 there is table 146 "Platform Event Log Format, Version 6, EPOW Section", which includes the "EPOW Event Modifier": For EPOW sensor value = 3 0x01 = Normal system shutdown with no additional delay 0x02 = Loss of utility power, system is running on UPS/Battery 0x03 = Loss of system critical functions, system should be shutdown 0x04 = Ambient temperature too high All other values = reserved We have a user space tool (rtas_errd) on LPAR to monitor for EPOW_SHUTDOWN_ON_UPS. Once it gets an event it initiates shutdown after predefined time. It also starts monitoring for any new EPOW events. If it receives "Power restored" event before predefined time it will cancel the shutdown. Otherwise after predefined time it will shutdown the system. Commit 79872e35469b ("powerpc/pseries: All events of EPOW_SYSTEM_SHUTDOWN must initiate shutdown") changed our handling of the "on UPS/Battery" case, to immediately shutdown the system. This breaks existing setups that rely on the userspace tool to delay shutdown and let the system run on the UPS. Fixes: 79872e35469b ("powerpc/pseries: All events of EPOW_SYSTEM_SHUTDOWN must initiate shutdown") Cc: stable@vger.kernel.org # v4.0+ Signed-off-by: Vasant Hegde [mpe: Massage change log and add PAPR references] Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20200820061844.306460-1-hegdevasant@linux.vnet.ibm.com Signed-off-by: Greg Kroah-Hartman

powerpc/pseries/hotplug-cpu: wait indefinitely for vCPU death

2020-08-26T09:42:22Z

[ Upstream commit 801980f6497946048709b9b09771a1729551d705 ] For a power9 KVM guest with XIVE enabled, running a test loop where we hotplug 384 vcpus and then unplug them, the following traces can be seen (generally within a few loops) either from the unplugged vcpu: cpu 65 (hwid 65) Ready to die... Querying DEAD? cpu 66 (66) shows 2 list_del corruption. next->prev should be c00a000002470208, but was c00a000002470048 ------------[ cut here ]------------ kernel BUG at lib/list_debug.c:56! Oops: Exception in kernel mode, sig: 5 [#1] LE SMP NR_CPUS=2048 NUMA pSeries Modules linked in: fuse nft_fib_inet nft_fib_ipv4 nft_fib_ipv6 ... CPU: 66 PID: 0 Comm: swapper/66 Kdump: loaded Not tainted 4.18.0-221.el8.ppc64le #1 NIP: c0000000007ab50c LR: c0000000007ab508 CTR: 00000000000003ac REGS: c0000009e5a17840 TRAP: 0700 Not tainted (4.18.0-221.el8.ppc64le) MSR: 800000000282b033 CR: 28000842 XER: 20040000 ... NIP __list_del_entry_valid+0xac/0x100 LR __list_del_entry_valid+0xa8/0x100 Call Trace: __list_del_entry_valid+0xa8/0x100 (unreliable) free_pcppages_bulk+0x1f8/0x940 free_unref_page+0xd0/0x100 xive_spapr_cleanup_queue+0x148/0x1b0 xive_teardown_cpu+0x1bc/0x240 pseries_mach_cpu_die+0x78/0x2f0 cpu_die+0x48/0x70 arch_cpu_idle_dead+0x20/0x40 do_idle+0x2f4/0x4c0 cpu_startup_entry+0x38/0x40 start_secondary+0x7bc/0x8f0 start_secondary_prolog+0x10/0x14 or on the worker thread handling the unplug: pseries-hotplug-cpu: Attempting to remove CPU , drc index: 1000013a Querying DEAD? cpu 314 (314) shows 2 BUG: Bad page state in process kworker/u768:3 pfn:95de1 cpu 314 (hwid 314) Ready to die... page:c00a000002577840 refcount:0 mapcount:-128 mapping:0000000000000000 index:0x0 flags: 0x5ffffc00000000() raw: 005ffffc00000000 5deadbeef0000100 5deadbeef0000200 0000000000000000 raw: 0000000000000000 0000000000000000 00000000ffffff7f 0000000000000000 page dumped because: nonzero mapcount Modules linked in: kvm xt_CHECKSUM ipt_MASQUERADE xt_conntrack ... CPU: 0 PID: 548 Comm: kworker/u768:3 Kdump: loaded Not tainted 4.18.0-224.el8.bz1856588.ppc64le #1 Workqueue: pseries hotplug workque pseries_hp_work_fn Call Trace: dump_stack+0xb0/0xf4 (unreliable) bad_page+0x12c/0x1b0 free_pcppages_bulk+0x5bc/0x940 page_alloc_cpu_dead+0x118/0x120 cpuhp_invoke_callback.constprop.5+0xb8/0x760 _cpu_down+0x188/0x340 cpu_down+0x5c/0xa0 cpu_subsys_offline+0x24/0x40 device_offline+0xf0/0x130 dlpar_offline_cpu+0x1c4/0x2a0 dlpar_cpu_remove+0xb8/0x190 dlpar_cpu_remove_by_index+0x12c/0x150 dlpar_cpu+0x94/0x800 pseries_hp_work_fn+0x128/0x1e0 process_one_work+0x304/0x5d0 worker_thread+0xcc/0x7a0 kthread+0x1ac/0x1c0 ret_from_kernel_thread+0x5c/0x80 The latter trace is due to the following sequence: page_alloc_cpu_dead drain_pages drain_pages_zone free_pcppages_bulk where drain_pages() in this case is called under the assumption that the unplugged cpu is no longer executing. To ensure that is the case, and early call is made to __cpu_die()->pseries_cpu_die(), which runs a loop that waits for the cpu to reach a halted state by polling its status via query-cpu-stopped-state RTAS calls. It only polls for 25 iterations before giving up, however, and in the trace above this results in the following being printed only .1 seconds after the hotplug worker thread begins processing the unplug request: pseries-hotplug-cpu: Attempting to remove CPU , drc index: 1000013a Querying DEAD? cpu 314 (314) shows 2 At that point the worker thread assumes the unplugged CPU is in some unknown/dead state and procedes with the cleanup, causing the race with the XIVE cleanup code executed by the unplugged CPU. Fix this by waiting indefinitely, but also making an effort to avoid spurious lockup messages by allowing for rescheduling after polling the CPU status and printing a warning if we wait for longer than 120s. Fixes: eac1e731b59ee ("powerpc/xive: guest exploitation of the XIVE interrupt controller") Suggested-by: Michael Ellerman Signed-off-by: Michael Roth Tested-by: Greg Kurz Reviewed-by: Thiago Jung Bauermann Reviewed-by: Greg Kurz [mpe: Trim oopses in change log slightly for readability] Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20200811161544.10513-1-mdroth@linux.vnet.ibm.com Signed-off-by: Sasha Levin

pseries: Fix 64 bit logical memory block panic

2020-08-21T11:07:29Z

commit 89c140bbaeee7a55ed0360a88f294ead2b95201b upstream. Booting with a 4GB LMB size causes us to panic: qemu-system-ppc64: OS terminated: OS panic: Memory block size not suitable: 0x0 Fix pseries_memory_block_size() to handle 64 bit LMBs. Cc: stable@vger.kernel.org Signed-off-by: Anton Blanchard Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20200715000820.1255764-1-anton@ozlabs.org Signed-off-by: Greg Kroah-Hartman

powerpc/pseries/hotplug-cpu: Remove double free in error path

2020-08-19T06:24:03Z

[ Upstream commit a0ff72f9f5a780341e7ff5e9ba50a0dad5fa1980 ] In the unlikely event that the device tree lacks a /cpus node, find_dlpar_cpus_to_add() oddly frees the cpu_drcs buffer it has been passed before returning an error. Its only caller also frees the buffer on error. Remove the less conventional kfree() of a caller-supplied buffer from find_dlpar_cpus_to_add(). Fixes: 90edf184b9b7 ("powerpc/pseries: Add CPU dlpar add functionality") Signed-off-by: Nathan Lynch Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20190919231633.1344-1-nathanl@linux.ibm.com Signed-off-by: Sasha Levin

powerpc/rtas: don't online CPUs for partition suspend

2020-08-19T06:23:54Z

[ Upstream commit ec2fc2a9e9bbad9023aab65bc472ce7a3ca8608f ] Partition suspension, used for hibernation and migration, requires that the OS place all but one of the LPAR's processor threads into one of two states prior to calling the ibm,suspend-me RTAS function: * the architected offline state (via RTAS stop-self); or * the H_JOIN hcall, which does not return until the partition resumes execution Using H_CEDE as the offline mode, introduced by commit 3aa565f53c39 ("powerpc/pseries: Add hooks to put the CPU into an appropriate offline state"), means that any threads which are offline from Linux's point of view must be moved to one of those two states before a partition suspension can proceed. This was eventually addressed in commit 120496ac2d2d ("powerpc: Bring all threads online prior to migration/hibernation"), which added code to temporarily bring up any offline processor threads so they can call H_JOIN. Conceptually this is fine, but the implementation has had multiple races with cpu hotplug operations initiated from user space[1][2][3], the error handling is fragile, and it generates user-visible cpu hotplug events which is a lot of noise for a platform feature that's supposed to minimize disruption to workloads. With commit 3aa565f53c39 ("powerpc/pseries: Add hooks to put the CPU into an appropriate offline state") reverted, this code becomes unnecessary, so remove it. Since any offline CPUs now are truly offline from the platform's point of view, it is no longer necessary to bring up CPUs only to have them call H_JOIN and then go offline again upon resuming. Only active threads are required to call H_JOIN; stopped threads can be left alone. [1] commit a6717c01ddc2 ("powerpc/rtas: use device model APIs and serialization during LPM") [2] commit 9fb603050ffd ("powerpc/rtas: retry when cpu offline races with suspend/migration") [3] commit dfd718a2ed1f ("powerpc/rtas: Fix a potential race between CPU-Offline & Migration") Fixes: 120496ac2d2d ("powerpc: Bring all threads online prior to migration/hibernation") Signed-off-by: Nathan Lynch Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20200612051238.1007764-3-nathanl@linux.ibm.com Signed-off-by: Sasha Levin

powerpc/pseries: remove cede offline state for CPUs

2020-08-19T06:23:54Z

[ Upstream commit 48f6e7f6d948b56489da027bc3284c709b939d28 ] This effectively reverts commit 3aa565f53c39 ("powerpc/pseries: Add hooks to put the CPU into an appropriate offline state"), which added an offline mode for CPUs which uses the H_CEDE hcall instead of the architected stop-self RTAS function in order to facilitate "folding" of dedicated mode processors on PowerVM platforms to achieve energy savings. This has been the default offline mode since its introduction. There's nothing about stop-self that would prevent the hypervisor from achieving the energy savings available via H_CEDE, so the original premise of this change appears to be flawed. I also have encountered the claim that the transition to and from ceded state is much faster than stop-self/start-cpu. Certainly we would not want to use stop-self as an *idle* mode. That is what H_CEDE is for. However, this difference is insignificant in the context of Linux CPU hotplug, where the latency of an offline or online operation on current systems is on the order of 100ms, mainly attributable to all the various subsystems' cpuhp callbacks. The cede offline mode also prevents accurate accounting, as discussed before: https://lore.kernel.org/linuxppc-dev/1571740391-3251-1-git-send-email-ego@linux.vnet.ibm.com/ Unconditionally use stop-self to offline processor threads. This is the architected method for offlining CPUs on PAPR systems. The "cede_offline" boot parameter is rendered obsolete. Removing this code enables the removal of the partition suspend code which temporarily onlines all present CPUs. Fixes: 3aa565f53c39 ("powerpc/pseries: Add hooks to put the CPU into an appropriate offline state") Signed-off-by: Nathan Lynch Reviewed-by: Gautham R. Shenoy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20200612051238.1007764-2-nathanl@linux.ibm.com Signed-off-by: Sasha Levin

powerpc/pseries/ras: Fix FWNMI_VALID off by one

2020-06-24T15:48:48Z

[ Upstream commit deb70f7a35a22dffa55b2c3aac71bc6fb0f486ce ] This was discovered developing qemu fwnmi sreset support. This off-by-one bug means the last 16 bytes of the rtas area can not be used for a 16 byte save area. It's not a serious bug, and QEMU implementation has to retain a workaround for old kernels, but it's good to tighten it. Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman Acked-by: Mahesh Salgaonkar Link: https://lore.kernel.org/r/20200508043408.886394-7-npiggin@gmail.com Signed-off-by: Sasha Levin

Merge tag 'powerpc-5.7-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

2020-04-09T18:01:42Z

Pull more powerpc updates from Michael Ellerman: "The bulk of this is the series to make CONFIG_COMPAT user-selectable, it's been around for a long time but was blocked behind the syscall-in-C series. Plus there's also a few fixes and other minor things. Summary: - A fix for a crash in machine check handling on pseries (ie. guests) - A small series to make it possible to disable CONFIG_COMPAT, and turn it off by default for ppc64le where it's not used. - A few other miscellaneous fixes and small improvements. Thanks to: Alexey Kardashevskiy, Anju T Sudhakar, Arnd Bergmann, Christophe Leroy, Dan Carpenter, Ganesh Goudar, Geert Uytterhoeven, Geoff Levand, Mahesh Salgaonkar, Markus Elfring, Michal Suchanek, Nicholas Piggin, Stephen Boyd, Wen Xiong" * tag 'powerpc-5.7-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: selftests/powerpc: Always build the tm-poison test 64-bit powerpc: Improve ppc_save_regs() Revert "powerpc/64: irq_work avoid interrupt when called with hardware irqs enabled" powerpc/time: Replace by powerpc/pseries/ddw: Extend upper limit for huge DMA window for persistent memory powerpc/perf: split callchain.c by bitness powerpc/64: Make COMPAT user-selectable disabled on littleendian by default. powerpc/64: make buildable without CONFIG_COMPAT powerpc/perf: consolidate valid_user_sp -> invalid_user_sp powerpc/perf: consolidate read_user_stack_32 powerpc: move common register copy functions from signal_32.c to signal.c powerpc: Add back __ARCH_WANT_SYS_LLSEEK macro powerpc/ps3: Set CONFIG_UEVENT_HELPER=y in ps3_defconfig powerpc/ps3: Remove an unneeded NULL check powerpc/ps3: Remove duplicate error message powerpc/powernv: Re-enable imc trace-mode in kernel powerpc/perf: Implement a global lock to avoid races between trace, core and thread imc events. powerpc/pseries: Fix MCE handling on pseries selftests/eeh: Skip ahci adapters powerpc/64s: Fix doorbell wakeup msgclr optimisation

Merge tag 'libnvdimm-for-5.7' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm

2020-04-09T04:03:40Z

Pull libnvdimm and dax updates from Dan Williams: "There were multiple touches outside of drivers/nvdimm/ this round to add cross arch compatibility to the devm_memremap_pages() interface, enhance numa information for persistent memory ranges, and add a zero_page_range() dax operation. This cycle I switched from the patchwork api to Konstantin's b4 script for collecting tags (from x86, PowerPC, filesystem, and device-mapper folks), and everything looks to have gone ok there. This has all appeared in -next with no reported issues. Summary: - Add support for region alignment configuration and enforcement to fix compatibility across architectures and PowerPC page size configurations. - Introduce 'zero_page_range' as a dax operation. This facilitates filesystem-dax operation without a block-device. - Introduce phys_to_target_node() to facilitate drivers that want to know resulting numa node if a given reserved address range was onlined. - Advertise a persistence-domain for of_pmem and papr_scm. The persistence domain indicates where cpu-store cycles need to reach in the platform-memory subsystem before the platform will consider them power-fail protected. - Promote numa_map_to_online_node() to a cross-kernel generic facility. - Save x86 numa information to allow for node-id lookups for reserved memory ranges, deploy that capability for the e820-pmem driver. - Pick up some miscellaneous minor fixes, that missed v5.6-final, including a some smatch reports in the ioctl path and some unit test compilation fixups. - Fixup some flexible-array declarations" * tag 'libnvdimm-for-5.7' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (29 commits) dax: Move mandatory ->zero_page_range() check in alloc_dax() dax,iomap: Add helper dax_iomap_zero() to zero a range dax: Use new dax zero page method for zeroing a page dm,dax: Add dax zero_page_range operation s390,dcssblk,dax: Add dax zero_page_range operation to dcssblk driver dax, pmem: Add a dax operation zero_page_range pmem: Add functions for reading/writing page to/from pmem libnvdimm: Update persistence domain value for of_pmem and papr_scm device tools/test/nvdimm: Fix out of tree build libnvdimm/region: Fix build error libnvdimm/region: Replace zero-length array with flexible-array member libnvdimm/label: Replace zero-length array with flexible-array member ACPI: NFIT: Replace zero-length array with flexible-array member libnvdimm/region: Introduce an 'align' attribute libnvdimm/region: Introduce NDD_LABELING libnvdimm/namespace: Enforce memremap_compat_align() libnvdimm/pfn: Prevent raw mode fallback if pfn-infoblock valid libnvdimm: Out of bounds read in __nd_ioctl() acpi/nfit: improve bounds checking for 'func' mm/memremap_pages: Introduce memremap_compat_align() ...

Merge tag 'powerpc-5.7-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

2020-04-05T18:12:59Z

Pull powerpc updates from Michael Ellerman: "Slightly late as I had to rebase mid-week to insert a bug fix: - A large series from Nick for 64-bit to further rework our exception vectors, and rewrite portions of the syscall entry/exit and interrupt return in C. The result is much easier to follow code that is also faster in general. - Cleanup of our ptrace code to split various parts out that had become badly intertwined with #ifdefs over the years. - Changes to our NUMA setup under the PowerVM hypervisor which should hopefully avoid non-sensical topologies which can lead to warnings from the workqueue code and other problems. - MAINTAINERS updates to remove some of our old orphan entries and update the status of others. - Quite a few other small changes and fixes all over the map. Thanks to: Abdul Haleem, afzal mohammed, Alexey Kardashevskiy, Andrew Donnellan, Aneesh Kumar K.V, Balamuruhan S, Cédric Le Goater, Chen Zhou, Christophe JAILLET, Christophe Leroy, Christoph Hellwig, Clement Courbet, Daniel Axtens, David Gibson, Douglas Miller, Fabiano Rosas, Fangrui Song, Ganesh Goudar, Gautham R. Shenoy, Greg Kroah-Hartman, Greg Kurz, Gustavo Luiz Duarte, Hari Bathini, Ilie Halip, Jan Kara, Joe Lawrence, Joe Perches, Kajol Jain, Larry Finger, Laurentiu Tudor, Leonardo Bras, Libor Pechacek, Madhavan Srinivasan, Mahesh Salgaonkar, Masahiro Yamada, Masami Hiramatsu, Mauricio Faria de Oliveira, Michael Neuling, Michal Suchanek, Mike Rapoport, Nageswara R Sastry, Nathan Chancellor, Nathan Lynch, Naveen N. Rao, Nicholas Piggin, Nick Desaulniers, Oliver O'Halloran, Po-Hsu Lin, Pratik Rajesh Sampat, Rasmus Villemoes, Ravi Bangoria, Roman Bolshakov, Sam Bobroff, Sandipan Das, Santosh S, Sedat Dilek, Segher Boessenkool, Shilpasri G Bhat, Sourabh Jain, Srikar Dronamraju, Stephen Rothwell, Tyrel Datwyler, Vaibhav Jain, YueHaibing" * tag 'powerpc-5.7-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (158 commits) powerpc: Make setjmp/longjmp signature standard powerpc/cputable: Remove unnecessary copy of cpu_spec->oprofile_type powerpc: Suppress .eh_frame generation powerpc: Drop -fno-dwarf2-cfi-asm powerpc/32: drop unused ISA_DMA_THRESHOLD powerpc/powernv: Add documentation for the opal sensor_groups sysfs interfaces selftests/powerpc: Fix try-run when source tree is not writable powerpc/vmlinux.lds: Explicitly retain .gnu.hash powerpc/ptrace: move ptrace_triggered() into hw_breakpoint.c powerpc/ptrace: create ppc_gethwdinfo() powerpc/ptrace: create ptrace_get_debugreg() powerpc/ptrace: split out ADV_DEBUG_REGS related functions. powerpc/ptrace: move register viewing functions out of ptrace.c powerpc/ptrace: split out TRANSACTIONAL_MEM related functions. powerpc/ptrace: split out SPE related functions. powerpc/ptrace: split out ALTIVEC related functions. powerpc/ptrace: split out VSX related functions. powerpc/ptrace: drop PARAMETER_SAVE_AREA_OFFSET powerpc/ptrace: drop unnecessary #ifdefs CONFIG_PPC64 powerpc/ptrace: remove unused header includes ...