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2023-08-14Merge branch 'topic/cpu-smt' into nextGravatar Michael Ellerman 1-1/+7
Merge SMT changes we are sharing with the tip tree.
2023-08-02powerpc: Add HOTPLUG_SMT supportGravatar Michael Ellerman 1-1/+7
Add support for HOTPLUG_SMT, which enables the generic sysfs SMT support files in /sys/devices/system/cpu/smt, as well as the "nosmt" boot parameter. Implement the recently added hooks to allow partial SMT states, allow any number of threads per core. Tie the config symbol to HOTPLUG_CPU, which enables it on the major platforms that support SMT. If there are other platforms that want the SMT support that can be tweaked in future. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> [ldufour: remove topology_smt_supported] [ldufour: remove topology_smt_threads_supported] [ldufour: select CONFIG_SMT_NUM_THREADS_DYNAMIC] [ldufour: update kernel-parameters.txt] Signed-off-by: Laurent Dufour <ldufour@linux.ibm.com> Link: https://msgid.link/20230705145143.40545-10-ldufour@linux.ibm.com
2023-08-02powerpc: Account mm_cpumask and active_cpus in init_mmGravatar Nicholas Piggin 1-0/+12
init_mm mm_cpumask and context.active_cpus is not maintained at boot and hotplug. This seems to be harmless because init_mm does not have a userspace and so never gets user TLBs flushed, but it looks odd and it prevents some sanity checks being added. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/20230524060821.148015-2-npiggin@gmail.com
2023-06-30Merge tag 'powerpc-6.5-1' of ↵Gravatar Linus Torvalds 1-2/+2
git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Pull powerpc updates from Michael Ellerman: - Extend KCSAN support to 32-bit and BookE. Add some KCSAN annotations - Make ELFv2 ABI the default for 64-bit big-endian kernel builds, and use the -mprofile-kernel option (kernel specific ftrace ABI) for big endian ELFv2 kernels - Add initial Dynamic Execution Control Register (DEXCR) support, and allow the ROP protection instructions to be used on Power 10 - Various other small features and fixes Thanks to Aditya Gupta, Aneesh Kumar K.V, Benjamin Gray, Brian King, Christophe Leroy, Colin Ian King, Dmitry Torokhov, Gaurav Batra, Jean Delvare, Joel Stanley, Marco Elver, Masahiro Yamada, Nageswara R Sastry, Nathan Chancellor, Naveen N Rao, Nayna Jain, Nicholas Piggin, Paul Gortmaker, Randy Dunlap, Rob Herring, Rohan McLure, Russell Currey, Sachin Sant, Timothy Pearson, Tom Rix, and Uwe Kleine-König. * tag 'powerpc-6.5-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (76 commits) powerpc: remove checks for binutils older than 2.25 powerpc: Fail build if using recordmcount with binutils v2.37 powerpc/iommu: TCEs are incorrectly manipulated with DLPAR add/remove of memory powerpc/iommu: Only build sPAPR access functions on pSeries powerpc: powernv: Annotate data races in opal events powerpc: Mark writes registering ipi to host cpu through kvm and polling powerpc: Annotate accesses to ipi message flags powerpc: powernv: Fix KCSAN datarace warnings on idle_state contention powerpc: Mark [h]ssr_valid accesses in check_return_regs_valid powerpc: qspinlock: Enforce qnode writes prior to publishing to queue powerpc: qspinlock: Mark accesses to qnode lock checks powerpc/powernv/pci: Remove last IODA1 defines powerpc/powernv/pci: Remove MVE code powerpc/powernv/pci: Remove ioda1 support powerpc: 52xx: Make immr_id DT match tables static powerpc: mpc512x: Remove open coded "ranges" parsing powerpc: fsl_soc: Use of_range_to_resource() for "ranges" parsing powerpc: fsl: Use of_property_read_reg() to parse "reg" powerpc: fsl_rio: Use of_range_to_resource() for "ranges" parsing macintosh: Use of_property_read_reg() to parse "reg" ...
2023-06-27Merge tag 'objtool-core-2023-06-27' of ↵Gravatar Linus Torvalds 1-0/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull objtool updates from Ingo Molar: "Build footprint & performance improvements: - Reduce memory usage with CONFIG_DEBUG_INFO=y In the worst case of an allyesconfig+CONFIG_DEBUG_INFO=y kernel, DWARF creates almost 200 million relocations, ballooning objtool's peak heap usage to 53GB. These patches reduce that to 25GB. On a distro-type kernel with kernel IBT enabled, they reduce objtool's peak heap usage from 4.2GB to 2.8GB. These changes also improve the runtime significantly. Debuggability improvements: - Add the unwind_debug command-line option, for more extend unwinding debugging output - Limit unreachable warnings to once per function - Add verbose option for disassembling affected functions - Include backtrace in verbose mode - Detect missing __noreturn annotations - Ignore exc_double_fault() __noreturn warnings - Remove superfluous global_noreturns entries - Move noreturn function list to separate file - Add __kunit_abort() to noreturns Unwinder improvements: - Allow stack operations in UNWIND_HINT_UNDEFINED regions - drm/vmwgfx: Add unwind hints around RBP clobber Cleanups: - Move the x86 entry thunk restore code into thunk functions - x86/unwind/orc: Use swap() instead of open coding it - Remove unnecessary/unused variables Fixes for modern stack canary handling" * tag 'objtool-core-2023-06-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (42 commits) x86/orc: Make the is_callthunk() definition depend on CONFIG_BPF_JIT=y objtool: Skip reading DWARF section data objtool: Free insns when done objtool: Get rid of reloc->rel[a] objtool: Shrink elf hash nodes objtool: Shrink reloc->sym_reloc_entry objtool: Get rid of reloc->jump_table_start objtool: Get rid of reloc->addend objtool: Get rid of reloc->type objtool: Get rid of reloc->offset objtool: Get rid of reloc->idx objtool: Get rid of reloc->list objtool: Allocate relocs in advance for new rela sections objtool: Add for_each_reloc() objtool: Don't free memory in elf_close() objtool: Keep GElf_Rel[a] structs synced objtool: Add elf_create_section_pair() objtool: Add mark_sec_changed() objtool: Fix reloc_hash size objtool: Consolidate rel/rela handling ...
2023-06-21powerpc: Annotate accesses to ipi message flagsGravatar Rohan McLure 1-2/+2
IPI message flags are observed and consequently consumed in the smp_ipi_demux_relaxed function, which handles these message sources until it observes none more arriving. Mark the checked loop guard with READ_ONCE, to signal to KCSAN that the read is known to be volatile, and that non-determinism is expected. Mark write for message source in smp_muxed_ipi_set_message(). Signed-off-by: Rohan McLure <rmclure@linux.ibm.com> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/20230510033117.1395895-8-rmclure@linux.ibm.com
2023-06-05locking/atomic: treewide: use raw_atomic*_<op>()Gravatar Mark Rutland 1-6/+6
Now that we have raw_atomic*_<op>() definitions, there's no need to use arch_atomic*_<op>() definitions outside of the low-level atomic definitions. Move treewide users of arch_atomic*_<op>() over to the equivalent raw_atomic*_<op>(). There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20230605070124.3741859-19-mark.rutland@arm.com
2023-05-16start_kernel: Add __no_stack_protector function attributeGravatar ndesaulniers@google.com 1-0/+1
Back during the discussion of commit a9a3ed1eff36 ("x86: Fix early boot crash on gcc-10, third try") we discussed the need for a function attribute to control the omission of stack protectors on a per-function basis; at the time Clang had support for no_stack_protector but GCC did not. This was fixed in gcc-11. Now that the function attribute is available, let's start using it. Callers of boot_init_stack_canary need to use this function attribute unless they're compiled with -fno-stack-protector, otherwise the canary stored in the stack slot of the caller will differ upon the call to boot_init_stack_canary. This will lead to a call to __stack_chk_fail() then panic. Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94722 Link: https://lore.kernel.org/all/20200316130414.GC12561@hirez.programming.kicks-ass.net/ Tested-by: Nathan Chancellor <nathan@kernel.org> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Acked-by: Miguel Ojeda <ojeda@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> Link: https://lore.kernel.org/r/20230412-no_stackp-v2-1-116f9fe4bbe7@google.com Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> Signed-off-by: ndesaulniers@google.com <ndesaulniers@google.com>
2023-04-28Merge tag 'smp-core-2023-04-27' of ↵Gravatar Linus Torvalds 1-2/+4
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull SMP cross-CPU function-call updates from Ingo Molnar: - Remove diagnostics and adjust config for CSD lock diagnostics - Add a generic IPI-sending tracepoint, as currently there's no easy way to instrument IPI origins: it's arch dependent and for some major architectures it's not even consistently available. * tag 'smp-core-2023-04-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: trace,smp: Trace all smp_function_call*() invocations trace: Add trace_ipi_send_cpu() sched, smp: Trace smp callback causing an IPI smp: reword smp call IPI comment treewide: Trace IPIs sent via smp_send_reschedule() irq_work: Trace self-IPIs sent via arch_irq_work_raise() smp: Trace IPIs sent via arch_send_call_function_ipi_mask() sched, smp: Trace IPIs sent via send_call_function_single_ipi() trace: Add trace_ipi_send_cpumask() kernel/smp: Make csdlock_debug= resettable locking/csd_lock: Remove per-CPU data indirection from CSD lock debugging locking/csd_lock: Remove added data from CSD lock debugging locking/csd_lock: Add Kconfig option for csd_debug default
2023-04-28Merge tag 'objtool-core-2023-04-27' of ↵Gravatar Linus Torvalds 1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull objtool updates from Ingo Molnar: - Mark arch_cpu_idle_dead() __noreturn, make all architectures & drivers that did this inconsistently follow this new, common convention, and fix all the fallout that objtool can now detect statically - Fix/improve the ORC unwinder becoming unreliable due to UNWIND_HINT_EMPTY ambiguity, split it into UNWIND_HINT_END_OF_STACK and UNWIND_HINT_UNDEFINED to resolve it - Fix noinstr violations in the KCSAN code and the lkdtm/stackleak code - Generate ORC data for __pfx code - Add more __noreturn annotations to various kernel startup/shutdown and panic functions - Misc improvements & fixes * tag 'objtool-core-2023-04-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (52 commits) x86/hyperv: Mark hv_ghcb_terminate() as noreturn scsi: message: fusion: Mark mpt_halt_firmware() __noreturn x86/cpu: Mark {hlt,resume}_play_dead() __noreturn btrfs: Mark btrfs_assertfail() __noreturn objtool: Include weak functions in global_noreturns check cpu: Mark nmi_panic_self_stop() __noreturn cpu: Mark panic_smp_self_stop() __noreturn arm64/cpu: Mark cpu_park_loop() and friends __noreturn x86/head: Mark *_start_kernel() __noreturn init: Mark start_kernel() __noreturn init: Mark [arch_call_]rest_init() __noreturn objtool: Generate ORC data for __pfx code x86/linkage: Fix padding for typed functions objtool: Separate prefix code from stack validation code objtool: Remove superfluous dead_end_function() check objtool: Add symbol iteration helpers objtool: Add WARN_INSN() scripts/objdump-func: Support multiple functions context_tracking: Fix KCSAN noinstr violation objtool: Add stackleak instrumentation to uaccess safe list ...
2023-03-28lazy tlb: introduce lazy tlb mm refcount helper functionsGravatar Nicholas Piggin 1-1/+1
Add explicit _lazy_tlb annotated functions for lazy tlb mm refcounting. This makes the lazy tlb mm references more obvious, and allows the refcounting scheme to be modified in later changes. There is no functional change with this patch. Link: https://lkml.kernel.org/r/20230203071837.1136453-3-npiggin@gmail.com Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nadav Amit <nadav.amit@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-03-24treewide: Trace IPIs sent via smp_send_reschedule()Gravatar Valentin Schneider 1-2/+4
To be able to trace invocations of smp_send_reschedule(), rename the arch-specific definitions of it to arch_smp_send_reschedule() and wrap it into an smp_send_reschedule() that contains a tracepoint. Changes to include the declaration of the tracepoint were driven by the following coccinelle script: @func_use@ @@ smp_send_reschedule(...); @include@ @@ #include <trace/events/ipi.h> @no_include depends on func_use && !include@ @@ #include <...> + + #include <trace/events/ipi.h> [csky bits] [riscv bits] Signed-off-by: Valentin Schneider <vschneid@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Guo Ren <guoren@kernel.org> Acked-by: Palmer Dabbelt <palmer@rivosinc.com> Link: https://lore.kernel.org/r/20230307143558.294354-6-vschneid@redhat.com
2023-03-08sched/idle: Mark arch_cpu_idle_dead() __noreturnGravatar Josh Poimboeuf 1-1/+1
Before commit 076cbf5d2163 ("x86/xen: don't let xen_pv_play_dead() return"), in Xen, when a previously offlined CPU was brought back online, it unexpectedly resumed execution where it left off in the middle of the idle loop. There were some hacks to make that work, but the behavior was surprising as do_idle() doesn't expect an offlined CPU to return from the dead (in arch_cpu_idle_dead()). Now that Xen has been fixed, and the arch-specific implementations of arch_cpu_idle_dead() also don't return, give it a __noreturn attribute. This will cause the compiler to complain if an arch-specific implementation might return. It also improves code generation for both caller and callee. Also fixes the following warning: vmlinux.o: warning: objtool: do_idle+0x25f: unreachable instruction Reported-by: Paul E. McKenney <paulmck@kernel.org> Tested-by: Paul E. McKenney <paulmck@kernel.org> Link: https://lore.kernel.org/r/60d527353da8c99d4cf13b6473131d46719ed16d.1676358308.git.jpoimboe@kernel.org Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2022-12-02powerpc: allow minimum sized kernel stack framesGravatar Nicholas Piggin 1-1/+1
This affects only 64-bit ELFv2 kernels, and reduces the minimum asm-created stack frame size from 112 to 32 byte on those kernels. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20221127124942.1665522-16-npiggin@gmail.com
2022-09-28powerpc/smp: poll cpu_callin_map more aggressively in __cpu_up()Gravatar Nathan Lynch 1-16/+22
At boot time, it is not necessary to delay between polls of cpu_callin_map when waiting for a kicked CPU to come up. Remove the delay intervals, but preserve the overall deadline (five seconds). At run time, the first poll result is usually negative and we incur a sleeping wait. If we spin on the callin word for a short time first, we can reduce __cpu_up() from dozens of milliseconds to under 1ms in the common case on a P9 LPAR: $ ppc64_cpu --smt=off $ bpftrace -e 'kprobe:__cpu_up { @start[tid] = nsecs; } kretprobe:__cpu_up /@start[tid]/ { @us = hist((nsecs - @start[tid]) / 1000); delete(@start[tid]); }' -c 'ppc64_cpu --smt=on' Before: @us: [16K, 32K) 85 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@| [32K, 64K) 13 |@@@@@@@ | After: @us: [128, 256) 95 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@| [256, 512) 3 |@ | Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220926220250.157022-1-nathanl@linux.ibm.com
2022-09-26powerpc: Remove CONFIG_PPC_FSL_BOOK3EGravatar Christophe Leroy 1-1/+1
CONFIG_PPC_FSL_BOOK3E is redundant with CONFIG_PPC_E500. Remove it. And rename five files accordingly. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> [mpe: Rename include guards to match new file names] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/795cb93b88c9a0279289712e674f39e3b108a1b4.1663606876.git.christophe.leroy@csgroup.eu
2022-08-07Merge tag 'mm-nonmm-stable-2022-08-06-2' of ↵Gravatar Linus Torvalds 1-7/+0
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull misc updates from Andrew Morton: "Updates to various subsystems which I help look after. lib, ocfs2, fatfs, autofs, squashfs, procfs, etc. A relatively small amount of material this time" * tag 'mm-nonmm-stable-2022-08-06-2' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (72 commits) scripts/gdb: ensure the absolute path is generated on initial source MAINTAINERS: kunit: add David Gow as a maintainer of KUnit mailmap: add linux.dev alias for Brendan Higgins mailmap: update Kirill's email profile: setup_profiling_timer() is moslty not implemented ocfs2: fix a typo in a comment ocfs2: use the bitmap API to simplify code ocfs2: remove some useless functions lib/mpi: fix typo 'the the' in comment proc: add some (hopefully) insightful comments bdi: remove enum wb_congested_state kernel/hung_task: fix address space of proc_dohung_task_timeout_secs lib/lzo/lzo1x_compress.c: replace ternary operator with min() and min_t() squashfs: support reading fragments in readahead call squashfs: implement readahead squashfs: always build "file direct" version of page actor Revert "squashfs: provide backing_dev_info in order to disable read-ahead" fs/ocfs2: Fix spelling typo in comment ia64: old_rr4 added under CONFIG_HUGETLB_PAGE proc: fix test for "vsyscall=xonly" boot option ...
2022-07-29profile: setup_profiling_timer() is moslty not implementedGravatar Ben Dooks 1-7/+0
The setup_profiling_timer() is mostly un-implemented by many architectures. In many places it isn't guarded by CONFIG_PROFILE which is needed for it to be used. Make it a weak symbol in kernel/profile.c and remove the 'return -EINVAL' implementations from the kenrel. There are a couple of architectures which do return 0 from the setup_profiling_timer() function but they don't seem to do anything else with it. To keep the /proc compatibility for now, leave these for a future update or removal. On ARM, this fixes the following sparse warning: arch/arm/kernel/smp.c:793:5: warning: symbol 'setup_profiling_timer' was not declared. Should it be static? Link: https://lkml.kernel.org/r/20220721195509.418205-1-ben-linux@fluff.org Signed-off-by: Ben Dooks <ben-linux@fluff.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-07-28powerpc/crash: save cpu register data in crash_smp_send_stop()Gravatar Hari Bathini 1-20/+9
During kdump, two set of NMI IPIs are sent to secondary CPUs, if 'crash_kexec_post_notifiers' option is set. The first set of NMI IPIs to stop the CPUs and the other set to collect register data. Instead, capture register data for secondary CPUs while stopping them itself. Also, fallback to smp_send_stop() in case the function gets called without kdump configured. Signed-off-by: Hari Bathini <hbathini@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220630064942.192283-1-hbathini@linux.ibm.com
2022-05-22powerpc: Fix all occurences of "the the"Gravatar Michael Ellerman 1-1/+1
Rather than waiting for the bots to fix these one-by-one, fix all occurences of "the the" throughout arch/powerpc. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220518142629.513007-1-mpe@ellerman.id.au
2022-05-22powerpc/kasan: Don't instrument non-maskable or raw interruptsGravatar Daniel Axtens 1-11/+11
Disable address sanitization for raw and non-maskable interrupt handlers, because they can run in real mode, where we cannot access the shadow memory. (Note that kasan_arch_is_ready() doesn't test for real mode, since it is a static branch for speed, and in any case not all the entry points to the generic KASAN code are protected by kasan_arch_is_ready guards.) The changes to interrupt_nmi_enter/exit_prepare() look larger than they actually are. The changes are equivalent to adding !IS_ENABLED(CONFIG_KASAN) to the conditions for calling nmi_enter() or nmi_exit() in real mode. That is, the code is equivalent to using the following condition for calling nmi_enter/exit: if (((!IS_ENABLED(CONFIG_PPC_BOOK3S_64) || !firmware_has_feature(FW_FEATURE_LPAR) || radix_enabled()) && !IS_ENABLED(CONFIG_KASAN) || (mfmsr() & MSR_DR)) That unwieldy condition has been split into several statements with comments, for easier reading. The nmi_ipi_lock functions that call atomic functions (i.e., nmi_ipi_lock_start(), nmi_ipi_lock() and nmi_ipi_unlock()), besides being marked noinstr, now call arch_atomic_* functions instead of atomic_* functions because with KASAN enabled, the atomic_* functions are wrappers which explicitly do address sanitization on their arguments. Since we are trying to avoid address sanitization, we have to use the lower-level arch_atomic_* versions. In hv_nmi_check_nonrecoverable(), the regs_set_unrecoverable() call has been open-coded so as to avoid having to either trust the inlining or mark regs_set_unrecoverable() as noinstr. [paulus@ozlabs.org: combined a few work-in-progress commits of Daniel's and wrote the commit message.] Signed-off-by: Daniel Axtens <dja@axtens.net> Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/YoTFGaKM8Pd46PIK@cleo
2022-05-08powerpc: Remove asm/prom.h from all files that don't need itGravatar Christophe Leroy 1-1/+0
Several files include asm/prom.h for no reason. Clean it up. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> [mpe: Drop change to prom_parse.c as reported by lkp@intel.com] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/7c9b8fda63dcf63e1b28f43e7ebdb95182cbc286.1646767214.git.christophe.leroy@csgroup.eu
2022-05-05powerpc: fix typos in commentsGravatar Julia Lawall 1-1/+1
Various spelling mistakes in comments. Detected with the help of Coccinelle. Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr> Reviewed-by: Joel Stanley <joel@jms.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220430185654.5855-1-Julia.Lawall@inria.fr
2022-03-08powerpc: Move C prototypes out of asm-prototypes.hGravatar Christophe Leroy 1-1/+0
We originally added asm-prototypes.h in commit 42f5b4cacd78 ("powerpc: Introduce asm-prototypes.h"). It's purpose was for prototypes of C functions that are only called from asm, in order to fix sparse warnings about missing prototypes. A few months later Nick added a different use case in commit 4efca4ed05cb ("kbuild: modversions for EXPORT_SYMBOL() for asm") for C prototypes for exported asm functions. This is basically the inverse of our original usage. Since then we've added various prototypes to asm-prototypes.h for both reasons, meaning we now need to unstitch it all. Dispatch prototypes of C functions into relevant headers and keep only the prototypes for functions defined in assembly. For the time being, leave prom_init() there because moving it into asm/prom.h or asm/setup.h conflicts with drivers/gpu/drm/nouveau/nvkm/subdev/bios/shadowrom.o This will be fixed later by untaggling asm/pci.h and asm/prom.h or by renaming the function in shadowrom.c Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/62d46904eca74042097acf4cb12c175e3067f3d1.1646413435.git.christophe.leroy@csgroup.eu
2022-03-08powerpc/smp: Declare current_set staticGravatar Christophe Leroy 1-1/+1
current_set extern not needed anymore since commit eafd825ed710 ("powerpc/64: Simplify __secondary_start paca->kstack handling") Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/a55eb65c9d7319f0af3c31e3f6ba36522f10003d.1646413435.git.christophe.leroy@csgroup.eu
2021-12-23powerpc/kernel: Add __init attribute to eligible functionsGravatar Nick Child 1-2/+3
Some functions defined in `arch/powerpc/kernel` (and one in `arch/powerpc/ kexec`) are deserving of an `__init` macro attribute. These functions are only called by other initialization functions and therefore should inherit the attribute. Also, change function declarations in header files to include `__init`. Signed-off-by: Nick Child <nick.child@ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211216220035.605465-2-nick.child@ibm.com
2021-12-09powerpc/fadump: Fix inaccurate CPU state info in vmcore generated with panicGravatar Hari Bathini 1-0/+10
In panic path, fadump is triggered via a panic notifier function. Before calling panic notifier functions, smp_send_stop() gets called, which stops all CPUs except the panic'ing CPU. Commit 8389b37dffdc ("powerpc: stop_this_cpu: remove the cpu from the online map.") and again commit bab26238bbd4 ("powerpc: Offline CPU in stop_this_cpu()") started marking CPUs as offline while stopping them. So, if a kernel has either of the above commits, vmcore captured with fadump via panic path would not process register data for all CPUs except the panic'ing CPU. Sample output of crash-utility with such vmcore: # crash vmlinux vmcore ... KERNEL: vmlinux DUMPFILE: vmcore [PARTIAL DUMP] CPUS: 1 DATE: Wed Nov 10 09:56:34 EST 2021 UPTIME: 00:00:42 LOAD AVERAGE: 2.27, 0.69, 0.24 TASKS: 183 NODENAME: XXXXXXXXX RELEASE: 5.15.0+ VERSION: #974 SMP Wed Nov 10 04:18:19 CST 2021 MACHINE: ppc64le (2500 Mhz) MEMORY: 8 GB PANIC: "Kernel panic - not syncing: sysrq triggered crash" PID: 3394 COMMAND: "bash" TASK: c0000000150a5f80 [THREAD_INFO: c0000000150a5f80] CPU: 1 STATE: TASK_RUNNING (PANIC) crash> p -x __cpu_online_mask __cpu_online_mask = $1 = { bits = {0x2, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0} } crash> crash> crash> p -x __cpu_active_mask __cpu_active_mask = $2 = { bits = {0xff, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0} } crash> While this has been the case since fadump was introduced, the issue was not identified for two probable reasons: - In general, the bulk of the vmcores analyzed were from crash due to exception. - The above did change since commit 8341f2f222d7 ("sysrq: Use panic() to force a crash") started using panic() instead of deferencing NULL pointer to force a kernel crash. But then commit de6e5d38417e ("powerpc: smp_send_stop do not offline stopped CPUs") stopped marking CPUs as offline till kernel commit bab26238bbd4 ("powerpc: Offline CPU in stop_this_cpu()") reverted that change. To ensure post processing register data of all other CPUs happens as intended, let panic() function take the crash friendly path (read crash_smp_send_stop()) with the help of crash_kexec_post_notifiers option. Also, as register data for all CPUs is captured by f/w, skip IPI callbacks here for fadump, to avoid any complications in finding the right backtraces. Signed-off-by: Hari Bathini <hbathini@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211207103719.91117-2-hbathini@linux.ibm.com
2021-12-09powerpc: handle kdump appropriately with crash_kexec_post_notifiers optionGravatar Hari Bathini 1-0/+30
Kdump can be triggered after panic_notifers since commit f06e5153f4ae2 ("kernel/panic.c: add "crash_kexec_post_notifiers" option for kdump after panic_notifers") introduced crash_kexec_post_notifiers option. But using this option would mean smp_send_stop(), that marks all other CPUs as offline, gets called before kdump is triggered. As a result, kdump routines fail to save other CPUs' registers. To fix this, kdump friendly crash_smp_send_stop() function was introduced with kernel commit 0ee59413c967 ("x86/panic: replace smp_send_stop() with kdump friendly version in panic path"). Override this kdump friendly weak function to handle crash_kexec_post_notifiers option appropriately on powerpc. Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Hari Bathini <hbathini@linux.ibm.com> [Fixed signature of crash_stop_this_cpu() - reported by lkp@intel.com] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211207103719.91117-1-hbathini@linux.ibm.com
2021-11-29powerpc/smp: Move setup_profiling_timer() under CONFIG_PROFILINGGravatar Michael Ellerman 1-0/+2
setup_profiling_timer() is only needed when CONFIG_PROFILING is enabled. Fixes the following W=1 warning when CONFIG_PROFILING=n: linux/arch/powerpc/kernel/smp.c:1638:5: error: no previous prototype for ‘setup_profiling_timer’ Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211124093254.1054750-5-mpe@ellerman.id.au
2021-11-02Merge tag 'devicetree-for-5.16' of ↵Gravatar Linus Torvalds 1-6/+1
git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux Pull devicetree updates from Rob Herring: - Convert /reserved-memory bindings to schemas - Convert a bunch of NFC bindings to schemas - Convert bindings to schema: Xilinx USB, Freescale DDR controller, Arm CCI-400, UBlox Neo-6M, 1-Wire GPIO, MSI controller, ASpeed LPC, OMAP and Inside-Secure HWRNG, register-bit-led, OV5640, Silead GSL1680, Elan ekth3000, Marvell bluetooth, TI wlcore, TI bluetooth, ESP ESP8089, tlm,trusted-foundations, Microchip cap11xx, Ralink SoCs and boards, and TI sysc - New binding schemas for: msi-ranges, Aspeed UART routing controller, palmbus, Xylon LogiCVC display controller, Mediatek's MT7621 SDRAM memory controller, and Apple M1 PCIe host - Run schema checks for %.dtb targets - Improve build time when using DT_SCHEMA_FILES - Improve error message when dtschema is not found - Various doc reference fixes in MAINTAINERS - Convert architectures to common CPU h/w ID parsing function of_get_cpu_hwid(). - Allow for empty NUMA node IDs which may be hotplugged - Cleanup of __fdt_scan_reserved_mem() - Constify device_node parameters - Update dtc to upstream v1.6.1-19-g0a3a9d3449c8. Adds new checks 'node_name_vs_property_name' and 'interrupt_map'. - Enable dtc 'unit_address_format' warning by default - Fix unittest EXPECT text for gpio hog errors * tag 'devicetree-for-5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux: (97 commits) dt-bindings: net: ti,bluetooth: Document default max-speed dt-bindings: pci: rcar-pci-ep: Document r8a7795 dt-bindings: net: qcom,ipa: IPA does support up to two iommus of/fdt: Remove of_scan_flat_dt() usage for __fdt_scan_reserved_mem() of: unittest: document intentional interrupt-map provider build warning of: unittest: fix EXPECT text for gpio hog errors of/unittest: Disable new dtc node_name_vs_property_name and interrupt_map warnings scripts/dtc: Update to upstream version v1.6.1-19-g0a3a9d3449c8 dt-bindings: arm: firmware: tlm,trusted-foundations: Convert txt bindings to yaml dt-bindings: display: tilcd: Fix endpoint addressing in example dt-bindings: input: microchip,cap11xx: Convert txt bindings to yaml dt-bindings: ufs: exynos-ufs: add exynosautov9 compatible dt-bindings: ufs: exynos-ufs: add io-coherency property dt-bindings: mips: convert Ralink SoCs and boards to schema dt-bindings: display: xilinx: Fix example with psgtr dt-bindings: net: nfc: nxp,pn544: Convert txt bindings to yaml dt-bindings: Add a help message when dtschema tools are missing dt-bindings: bus: ti-sysc: Update to use yaml binding dt-bindings: sram: Allow numbers in sram region node name dt-bindings: display: Document the Xylon LogiCVC display controller ...
2021-11-01Merge tag 'cpu-to-thread_info-v5.16-rc1' of ↵Gravatar Linus Torvalds 1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull thread_info update to move 'cpu' back from task_struct from Kees Cook: "Cross-architecture update to move task_struct::cpu back into thread_info on arm64, x86, s390, powerpc, and riscv. All Acked by arch maintainers. Quoting Ard Biesheuvel: 'Move task_struct::cpu back into thread_info Keeping CPU in task_struct is problematic for architectures that define raw_smp_processor_id() in terms of this field, as it requires linux/sched.h to be included, which causes a lot of pain in terms of circular dependencies (aka 'header soup') This series moves it back into thread_info (where it came from) for all architectures that enable THREAD_INFO_IN_TASK, addressing the header soup issue as well as some pointless differences in the implementations of task_cpu() and set_task_cpu()'" * tag 'cpu-to-thread_info-v5.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: riscv: rely on core code to keep thread_info::cpu updated powerpc: smp: remove hack to obtain offset of task_struct::cpu sched: move CPU field back into thread_info if THREAD_INFO_IN_TASK=y powerpc: add CPU field to struct thread_info s390: add CPU field to struct thread_info x86: add CPU field to struct thread_info arm64: add CPU field to struct thread_info
2021-10-20powerpc: Use of_get_cpu_hwid()Gravatar Rob Herring 1-6/+1
Replace open coded parsing of CPU nodes' 'reg' property with of_get_cpu_hwid(). Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: linuxppc-dev@lists.ozlabs.org Signed-off-by: Rob Herring <robh@kernel.org> Acked-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211006164332.1981454-8-robh@kernel.org
2021-10-20powerpc/smp: do not decrement idle task preempt count in CPU offlineGravatar Nathan Lynch 1-2/+0
With PREEMPT_COUNT=y, when a CPU is offlined and then onlined again, we get: BUG: scheduling while atomic: swapper/1/0/0x00000000 no locks held by swapper/1/0. CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.15.0-rc2+ #100 Call Trace: dump_stack_lvl+0xac/0x108 __schedule_bug+0xac/0xe0 __schedule+0xcf8/0x10d0 schedule_idle+0x3c/0x70 do_idle+0x2d8/0x4a0 cpu_startup_entry+0x38/0x40 start_secondary+0x2ec/0x3a0 start_secondary_prolog+0x10/0x14 This is because powerpc's arch_cpu_idle_dead() decrements the idle task's preempt count, for reasons explained in commit a7c2bb8279d2 ("powerpc: Re-enable preemption before cpu_die()"), specifically "start_secondary() expects a preempt_count() of 0." However, since commit 2c669ef6979c ("powerpc/preempt: Don't touch the idle task's preempt_count during hotplug") and commit f1a0a376ca0c ("sched/core: Initialize the idle task with preemption disabled"), that justification no longer holds. The idle task isn't supposed to re-enable preemption, so remove the vestigial preempt_enable() from the CPU offline path. Tested with pseries and powernv in qemu, and pseries on PowerVM. Fixes: 2c669ef6979c ("powerpc/preempt: Don't touch the idle task's preempt_count during hotplug") Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Reviewed-by: Valentin Schneider <valentin.schneider@arm.com> Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211015173902.2278118-1-nathanl@linux.ibm.com
2021-09-30sched: move CPU field back into thread_info if THREAD_INFO_IN_TASK=yGravatar Ard Biesheuvel 1-1/+1
THREAD_INFO_IN_TASK moved the CPU field out of thread_info, but this causes some issues on architectures that define raw_smp_processor_id() in terms of this field, due to the fact that #include'ing linux/sched.h to get at struct task_struct is problematic in terms of circular dependencies. Given that thread_info and task_struct are the same data structure anyway when THREAD_INFO_IN_TASK=y, let's move it back so that having access to the type definition of struct thread_info is sufficient to reference the CPU number of the current task. Note that this requires THREAD_INFO_IN_TASK's definition of the task_thread_info() helper to be updated, as task_cpu() takes a pointer-to-const, whereas task_thread_info() (which is used to generate lvalues as well), needs a non-const pointer. So make it a macro instead. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Michael Ellerman <mpe@ellerman.id.au>
2021-08-27powerpc/numa: Update cpu_cpu_map on CPU online/offlineGravatar Srikar Dronamraju 1-0/+3
cpu_cpu_map holds all the CPUs in the DIE. However in PowerPC, when onlining/offlining of CPUs, this mask doesn't get updated. This mask is however updated when CPUs are added/removed. So when both operations like online/offline of CPUs and adding/removing of CPUs are done simultaneously, then cpumaps end up broken. WARNING: CPU: 13 PID: 1142 at kernel/sched/topology.c:898 build_sched_domains+0xd48/0x1720 Modules linked in: rpadlpar_io rpaphp mptcp_diag xsk_diag tcp_diag udp_diag raw_diag inet_diag unix_diag af_packet_diag netlink_diag bonding tls nft_fib_inet nft_fib_ipv4 nft_fib_ipv6 nft_fib nft_reject_inet nf_reject_ipv4 nf_reject_ipv6 nft_reject nft_ct nft_chain_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 ip_set rfkill nf_tables nfnetlink pseries_rng xts vmx_crypto uio_pdrv_genirq uio binfmt_misc ip_tables xfs libcrc32c dm_service_time sd_mod t10_pi sg ibmvfc scsi_transport_fc ibmveth dm_multipath dm_mirror dm_region_hash dm_log dm_mod fuse CPU: 13 PID: 1142 Comm: kworker/13:2 Not tainted 5.13.0-rc6+ #28 Workqueue: events cpuset_hotplug_workfn NIP: c0000000001caac8 LR: c0000000001caac4 CTR: 00000000007088ec REGS: c00000005596f220 TRAP: 0700 Not tainted (5.13.0-rc6+) MSR: 8000000000029033 <SF,EE,ME,IR,DR,RI,LE> CR: 48828222 XER: 00000009 CFAR: c0000000001ea698 IRQMASK: 0 GPR00: c0000000001caac4 c00000005596f4c0 c000000001c4a400 0000000000000036 GPR04: 00000000fffdffff c00000005596f1d0 0000000000000027 c0000018cfd07f90 GPR08: 0000000000000023 0000000000000001 0000000000000027 c0000018fe68ffe8 GPR12: 0000000000008000 c00000001e9d1880 c00000013a047200 0000000000000800 GPR16: c000000001d3c7d0 0000000000000240 0000000000000048 c000000010aacd18 GPR20: 0000000000000001 c000000010aacc18 c00000013a047c00 c000000139ec2400 GPR24: 0000000000000280 c000000139ec2520 c000000136c1b400 c000000001c93060 GPR28: c00000013a047c20 c000000001d3c6c0 c000000001c978a0 000000000000000d NIP [c0000000001caac8] build_sched_domains+0xd48/0x1720 LR [c0000000001caac4] build_sched_domains+0xd44/0x1720 Call Trace: [c00000005596f4c0] [c0000000001caac4] build_sched_domains+0xd44/0x1720 (unreliable) [c00000005596f670] [c0000000001cc5ec] partition_sched_domains_locked+0x3ac/0x4b0 [c00000005596f710] [c0000000002804e4] rebuild_sched_domains_locked+0x404/0x9e0 [c00000005596f810] [c000000000283e60] rebuild_sched_domains+0x40/0x70 [c00000005596f840] [c000000000284124] cpuset_hotplug_workfn+0x294/0xf10 [c00000005596fc60] [c000000000175040] process_one_work+0x290/0x590 [c00000005596fd00] [c0000000001753c8] worker_thread+0x88/0x620 [c00000005596fda0] [c000000000181704] kthread+0x194/0x1a0 [c00000005596fe10] [c00000000000ccec] ret_from_kernel_thread+0x5c/0x70 Instruction dump: 485af049 60000000 2fa30800 409e0028 80fe0000 e89a00f8 e86100e8 38da0120 7f88e378 7ce53b78 4801fb91 60000000 <0fe00000> 39000000 38e00000 38c00000 Fix this by updating cpu_cpu_map aka cpumask_of_node() on every CPU online/offline. Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210826100521.412639-5-srikar@linux.vnet.ibm.com
2021-08-27powerpc/smp: Enable CACHE domain for shared processorGravatar Srikar Dronamraju 1-1/+1
Currently CACHE domain is not enabled on shared processor mode PowerVM LPARS. On PowerVM systems, 'ibm,thread-group' device-tree property 2 under cpu-device-node indicates which all CPUs share L2-cache. However 'ibm,thread-group' device-tree property 2 is a relatively new property. In absence of 'ibm,thread-group' property 2, 'l2-cache' device property under cpu-device-node could help system to identify CPUs sharing L2-cache. However this property is not exposed by PhyP in shared processor mode configurations. In absence of properties that inform OS about which CPUs share L2-cache, fallback on core boundary. Here are some stats from Power9 shared LPAR with the changes. $ lscpu Architecture: ppc64le Byte Order: Little Endian CPU(s): 32 On-line CPU(s) list: 0-31 Thread(s) per core: 8 Core(s) per socket: 1 Socket(s): 3 NUMA node(s): 2 Model: 2.2 (pvr 004e 0202) Model name: POWER9 (architected), altivec supported Hypervisor vendor: pHyp Virtualization type: para L1d cache: 32K L1i cache: 32K NUMA node0 CPU(s): 16-23 NUMA node1 CPU(s): 0-15,24-31 Physical sockets: 2 Physical chips: 1 Physical cores/chip: 10 Before patch $ grep -r . /sys/kernel/debug/sched/domains/cpu0/domain*/name Before /sys/kernel/debug/sched/domains/cpu0/domain0/name:SMT /sys/kernel/debug/sched/domains/cpu0/domain1/name:DIE /sys/kernel/debug/sched/domains/cpu0/domain2/name:NUMA After /sys/kernel/debug/sched/domains/cpu0/domain0/name:SMT /sys/kernel/debug/sched/domains/cpu0/domain1/name:CACHE /sys/kernel/debug/sched/domains/cpu0/domain2/name:DIE /sys/kernel/debug/sched/domains/cpu0/domain3/name:NUMA $ awk '/domain/{print $1, $2}' /proc/schedstat | sort -u | sed -e 's/00000000,//g' Before domain0 00000055 domain0 000000aa domain0 00005500 domain0 0000aa00 domain0 00550000 domain0 00aa0000 domain0 55000000 domain0 aa000000 domain1 00ff0000 domain1 ff00ffff domain2 ffffffff After domain0 00000055 domain0 000000aa domain0 00005500 domain0 0000aa00 domain0 00550000 domain0 00aa0000 domain0 55000000 domain0 aa000000 domain1 000000ff domain1 0000ff00 domain1 00ff0000 domain1 ff000000 domain2 ff00ffff domain2 ffffffff domain3 ffffffff (Lower is better) perf stat -a -r 5 -n perf bench sched pipe | tail -n 2 Before 153.798 +- 0.142 seconds time elapsed ( +- 0.09% ) After 111.545 +- 0.652 seconds time elapsed ( +- 0.58% ) which is an improvement of 27.47% Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210826100401.412519-4-srikar@linux.vnet.ibm.com
2021-08-27powerpc/smp: Update cpu_core_map on all PowerPc systemsGravatar Srikar Dronamraju 1-6/+5
lscpu() uses core_siblings to list the number of sockets in the system. core_siblings is set using topology_core_cpumask. While optimizing the powerpc bootup path, Commit 4ca234a9cbd7 ("powerpc/smp: Stop updating cpu_core_mask"). it was found that updating cpu_core_mask() ended up taking a lot of time. It was thought that on Powerpc, cpu_core_mask() would always be same as cpu_cpu_mask() i.e number of sockets will always be equal to number of nodes. As an optimization, cpu_core_mask() was made a snapshot of cpu_cpu_mask(). However that was found to be false with PowerPc KVM guests, where each node could have more than one socket. So with Commit c47f892d7aa6 ("powerpc/smp: Reintroduce cpu_core_mask"), cpu_core_mask was updated based on chip_id but in an optimized way using some mask manipulations and chip_id caching. However on non-PowerNV and non-pseries KVM guests (i.e not implementing cpu_to_chip_id(), continued to use a copy of cpu_cpu_mask(). There are two issues that were noticed on such systems 1. lscpu would report one extra socket. On a IBM,9009-42A (aka zz system) which has only 2 chips/ sockets/ nodes, lscpu would report Architecture: ppc64le Byte Order: Little Endian CPU(s): 160 On-line CPU(s) list: 0-159 Thread(s) per core: 8 Core(s) per socket: 6 Socket(s): 3 <-------------- NUMA node(s): 2 Model: 2.2 (pvr 004e 0202) Model name: POWER9 (architected), altivec supported Hypervisor vendor: pHyp Virtualization type: para L1d cache: 32K L1i cache: 32K L2 cache: 512K L3 cache: 10240K NUMA node0 CPU(s): 0-79 NUMA node1 CPU(s): 80-159 2. Currently cpu_cpu_mask is updated when a core is added/removed. However its not updated when smt mode switching or on CPUs are explicitly offlined. However all other percpu masks are updated to ensure only active/online CPUs are in the masks. This results in build_sched_domain traces since there will be CPUs in cpu_cpu_mask() but those CPUs are not present in SMT / CACHE / MC / NUMA domains. A loop of threads running smt mode switching and core add/remove will soon show this trace. Hence cpu_cpu_mask has to be update at smt mode switch. This will have impact on cpu_core_mask(). cpu_core_mask() is a snapshot of cpu_cpu_mask. Different CPUs within the same socket will end up having different cpu_core_masks since they are snapshots at different points of time. This means when lscpu will start reporting many more sockets than the actual number of sockets/ nodes / chips. Different ways to handle this problem: A. Update the snapshot aka cpu_core_mask for all CPUs whenever cpu_cpu_mask is updated. This would a non-optimal solution. B. Instead of a cpumask_var_t, make cpu_core_map a cpumask pointer pointing to cpu_cpu_mask. However percpu cpumask pointer is frowned upon and we need a clean way to handle PowerPc KVM guest which is not a snapshot. C. Update cpu_core_masks all PowerPc systems like in PowerPc KVM guests using mask manipulations. This approach is relatively simple and unifies with the existing code. D. On top of 3, we could also resurrect get_physical_package_id which could return a nid for the said CPU. However this is not needed at this time. Option C is the preferred approach for now. While this is somewhat a revert of Commit 4ca234a9cbd7 ("powerpc/smp: Stop updating cpu_core_mask"). 1. Plain revert has some conflicts 2. For chip_id == -1, the cpu_core_mask is made identical to cpu_cpu_mask, unlike previously where cpu_core_mask was set to a core if chip_id doesn't exist. This goes by the principle that if chip_id is not exposed, then sockets / chip / node share the same set of CPUs. With the fix, lscpu o/p would be Architecture: ppc64le Byte Order: Little Endian CPU(s): 160 On-line CPU(s) list: 0-159 Thread(s) per core: 8 Core(s) per socket: 6 Socket(s): 2 <-------------- NUMA node(s): 2 Model: 2.2 (pvr 004e 0202) Model name: POWER9 (architected), altivec supported Hypervisor vendor: pHyp Virtualization type: para L1d cache: 32K L1i cache: 32K L2 cache: 512K L3 cache: 10240K NUMA node0 CPU(s): 0-79 NUMA node1 CPU(s): 80-159 Fixes: 4ca234a9cbd7 ("powerpc/smp: Stop updating cpu_core_mask") Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210826100401.412519-3-srikar@linux.vnet.ibm.com
2021-08-27powerpc/smp: Fix a crash while booting kvm guest with nr_cpus=2Gravatar Srikar Dronamraju 1-1/+1
Aneesh reported a crash with a fairly recent upstream kernel when booting kernel whose commandline was appended with nr_cpus=2 1:mon> e cpu 0x1: Vector: 300 (Data Access) at [c000000008a67bd0] pc: c00000000002557c: cpu_to_chip_id+0x3c/0x100 lr: c000000000058380: start_secondary+0x460/0xb00 sp: c000000008a67e70 msr: 8000000000001033 dar: 10 dsisr: 80000 current = 0xc00000000891bb00 paca = 0xc0000018ff981f80 irqmask: 0x03 irq_happened: 0x01 pid = 0, comm = swapper/1 Linux version 5.13.0-rc3-15704-ga050a6d2b7e8 (kvaneesh@ltc-boston8) (gcc (Ubuntu 9.3.0-17ubuntu1~20.04) 9.3.0, GNU ld (GNU Binutils for Ubuntu) 2.34) #433 SMP Tue May 25 02:38:49 CDT 2021 1:mon> t [link register ] c000000000058380 start_secondary+0x460/0xb00 [c000000008a67e70] c000000008a67eb0 (unreliable) [c000000008a67eb0] c0000000000589d4 start_secondary+0xab4/0xb00 [c000000008a67f90] c00000000000c654 start_secondary_prolog+0x10/0x14 Current code assumes that num_possible_cpus() is always greater than threads_per_core. However this may not be true when using nr_cpus=2 or similar options. Handle the case where num_possible_cpus() is not an exact multiple of threads_per_core. Fixes: c1e53367dab1 ("powerpc/smp: Cache CPU to chip lookup") Reported-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Debugged-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210826100401.412519-2-srikar@linux.vnet.ibm.com
2021-08-04powerpc/smp: Use existing L2 cache_map cpumask to find L3 cache siblingsGravatar Parth Shah 1-21/+45
On POWER10 systems, the "ibm,thread-groups" property "2" indicates the cpus in thread-group share both L2 and L3 caches. Hence, use cache_property = 2 itself to find both the L2 and L3 cache siblings. Hence, create a new thread_group_l3_cache_map to keep list of L3 siblings, but fill the mask using same property "2" array. Signed-off-by: Parth Shah <parth@linux.ibm.com> Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210728175607.591679-4-parth@linux.ibm.com
2021-08-04powerpc/cacheinfo: Lookup cache by dt node and thread-group idGravatar Gautham R. Shenoy 1-2/+2
Currently the cacheinfo code on powerpc indexes the "cache" objects (modelling the L1/L2/L3 caches) where the key is device-tree node corresponding to that cache. On some of the POWER server platforms thread-groups within the core share different sets of caches (Eg: On SMT8 POWER9 systems, threads 0,2,4,6 of a core share L1 cache and threads 1,3,5,7 of the same core share another L1 cache). On such platforms, there is a single device-tree node corresponding to that cache and the cache-configuration within the threads of the core is indicated via "ibm,thread-groups" device-tree property. Since the current code is not aware of the "ibm,thread-groups" property, on the aforementoined systems, cacheinfo code still treats all the threads in the core to be sharing the cache because of the single device-tree node (In the earlier example, the cacheinfo code would says CPUs 0-7 share L1 cache). In this patch, we make the powerpc cacheinfo code aware of the "ibm,thread-groups" property. We indexe the "cache" objects by the key-pair (device-tree node, thread-group id). For any CPUX, for a given level of cache, the thread-group id is defined to be the first CPU in the "ibm,thread-groups" cache-group containing CPUX. For levels of cache which are not represented in "ibm,thread-groups" property, the thread-group id is -1. [parth: Remove "static" keyword for the definition of "thread_group_l1_cache_map" and "thread_group_l2_cache_map" to get rid of the compile error.] Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com> Signed-off-by: Parth Shah <parth@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210728175607.591679-2-parth@linux.ibm.com
2021-07-02Merge tag 'powerpc-5.14-1' of ↵Gravatar Linus Torvalds 1-0/+15
git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Pull powerpc updates from Michael Ellerman: - A big series refactoring parts of our KVM code, and converting some to C. - Support for ARCH_HAS_SET_MEMORY, and ARCH_HAS_STRICT_MODULE_RWX on some CPUs. - Support for the Microwatt soft-core. - Optimisations to our interrupt return path on 64-bit. - Support for userspace access to the NX GZIP accelerator on PowerVM on Power10. - Enable KUAP and KUEP by default on 32-bit Book3S CPUs. - Other smaller features, fixes & cleanups. Thanks to: Andy Shevchenko, Aneesh Kumar K.V, Arnd Bergmann, Athira Rajeev, Baokun Li, Benjamin Herrenschmidt, Bharata B Rao, Christophe Leroy, Daniel Axtens, Daniel Henrique Barboza, Finn Thain, Geoff Levand, Haren Myneni, Jason Wang, Jiapeng Chong, Joel Stanley, Jordan Niethe, Kajol Jain, Nathan Chancellor, Nathan Lynch, Naveen N. Rao, Nicholas Piggin, Nick Desaulniers, Paul Mackerras, Russell Currey, Sathvika Vasireddy, Shaokun Zhang, Stephen Rothwell, Sudeep Holla, Suraj Jitindar Singh, Tom Rix, Vaibhav Jain, YueHaibing, Zhang Jianhua, and Zhen Lei. * tag 'powerpc-5.14-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (218 commits) powerpc: Only build restart_table.c for 64s powerpc/64s: move ret_from_fork etc above __end_soft_masked powerpc/64s/interrupt: clean up interrupt return labels powerpc/64/interrupt: add missing kprobe annotations on interrupt exit symbols powerpc/64: enable MSR[EE] in irq replay pt_regs powerpc/64s/interrupt: preserve regs->softe for NMI interrupts powerpc/64s: add a table of implicit soft-masked addresses powerpc/64e: remove implicit soft-masking and interrupt exit restart logic powerpc/64e: fix CONFIG_RELOCATABLE build warnings powerpc/64s: fix hash page fault interrupt handler powerpc/4xx: Fix setup_kuep() on SMP powerpc/32s: Fix setup_{kuap/kuep}() on SMP powerpc/interrupt: Use names in check_return_regs_valid() powerpc/interrupt: Also use exit_must_hard_disable() on PPC32 powerpc/sysfs: Replace sizeof(arr)/sizeof(arr[0]) with ARRAY_SIZE powerpc/ptrace: Refactor regs_set_return_{msr/ip} powerpc/ptrace: Move set_return_regs_changed() before regs_set_return_{msr/ip} powerpc/stacktrace: Fix spurious "stale" traces in raise_backtrace_ipi() powerpc/pseries/vas: Include irqdomain.h powerpc: mark local variables around longjmp as volatile ...
2021-06-29Merge branch 'akpm' (patches from Andrew)Gravatar Linus Torvalds 1-1/+1
Merge misc updates from Andrew Morton: "191 patches. Subsystems affected by this patch series: kthread, ia64, scripts, ntfs, squashfs, ocfs2, kernel/watchdog, and mm (gup, pagealloc, slab, slub, kmemleak, dax, debug, pagecache, gup, swap, memcg, pagemap, mprotect, bootmem, dma, tracing, vmalloc, kasan, initialization, pagealloc, and memory-failure)" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (191 commits) mm,hwpoison: make get_hwpoison_page() call get_any_page() mm,hwpoison: send SIGBUS with error virutal address mm/page_alloc: split pcp->high across all online CPUs for cpuless nodes mm/page_alloc: allow high-order pages to be stored on the per-cpu lists mm: replace CONFIG_FLAT_NODE_MEM_MAP with CONFIG_FLATMEM mm: replace CONFIG_NEED_MULTIPLE_NODES with CONFIG_NUMA docs: remove description of DISCONTIGMEM arch, mm: remove stale mentions of DISCONIGMEM mm: remove CONFIG_DISCONTIGMEM m68k: remove support for DISCONTIGMEM arc: remove support for DISCONTIGMEM arc: update comment about HIGHMEM implementation alpha: remove DISCONTIGMEM and NUMA mm/page_alloc: move free_the_page mm/page_alloc: fix counting of managed_pages mm/page_alloc: improve memmap_pages dbg msg mm: drop SECTION_SHIFT in code comments mm/page_alloc: introduce vm.percpu_pagelist_high_fraction mm/page_alloc: limit the number of pages on PCP lists when reclaim is active mm/page_alloc: scale the number of pages that are batch freed ...
2021-06-29mm: replace CONFIG_NEED_MULTIPLE_NODES with CONFIG_NUMAGravatar Mike Rapoport 1-1/+1
After removal of DISCINTIGMEM the NEED_MULTIPLE_NODES and NUMA configuration options are equivalent. Drop CONFIG_NEED_MULTIPLE_NODES and use CONFIG_NUMA instead. Done with $ sed -i 's/CONFIG_NEED_MULTIPLE_NODES/CONFIG_NUMA/' \ $(git grep -wl CONFIG_NEED_MULTIPLE_NODES) $ sed -i 's/NEED_MULTIPLE_NODES/NUMA/' \ $(git grep -wl NEED_MULTIPLE_NODES) with manual tweaks afterwards. [rppt@linux.ibm.com: fix arm boot crash] Link: https://lkml.kernel.org/r/YMj9vHhHOiCVN4BF@linux.ibm.com Link: https://lkml.kernel.org/r/20210608091316.3622-9-rppt@kernel.org Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: David Hildenbrand <david@redhat.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Matt Turner <mattst88@gmail.com> Cc: Richard Henderson <rth@twiddle.net> Cc: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-25powerpc: Offline CPU in stop_this_cpu()Gravatar Nicholas Piggin 1-0/+11
printk_safe_flush_on_panic() has special lock breaking code for the case where we panic()ed with the console lock held. It relies on panic IPI causing other CPUs to mark themselves offline. Do as most other architectures do. This effectively reverts commit de6e5d38417e ("powerpc: smp_send_stop do not offline stopped CPUs"), unfortunately it may result in some false positive warnings, but the alternative is more situations where we can crash without getting messages out. Fixes: de6e5d38417e ("powerpc: smp_send_stop do not offline stopped CPUs") Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210623041245.865134-1-npiggin@gmail.com
2021-06-17powerpc/32s: Initialise KUAP and KUEP in CGravatar Christophe Leroy 1-0/+4
In order to selectively activate KUAP and KUEP in a following patch, perform KUAP and KUEP initialisation in C. Unlike PPC64, PPC32 doesn't have an early_setup_secondary(), so do it in start_secondary(). Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/87be72023448dd4e476744ed279b8c04b8d08a1c.1622708530.git.christophe.leroy@csgroup.eu
2021-05-12sched/core: Initialize the idle task with preemption disabledGravatar Valentin Schneider 1-1/+0
As pointed out by commit de9b8f5dcbd9 ("sched: Fix crash trying to dequeue/enqueue the idle thread") init_idle() can and will be invoked more than once on the same idle task. At boot time, it is invoked for the boot CPU thread by sched_init(). Then smp_init() creates the threads for all the secondary CPUs and invokes init_idle() on them. As the hotplug machinery brings the secondaries to life, it will issue calls to idle_thread_get(), which itself invokes init_idle() yet again. In this case it's invoked twice more per secondary: at _cpu_up(), and at bringup_cpu(). Given smp_init() already initializes the idle tasks for all *possible* CPUs, no further initialization should be required. Now, removing init_idle() from idle_thread_get() exposes some interesting expectations with regards to the idle task's preempt_count: the secondary startup always issues a preempt_disable(), requiring some reset of the preempt count to 0 between hot-unplug and hotplug, which is currently served by idle_thread_get() -> idle_init(). Given the idle task is supposed to have preemption disabled once and never see it re-enabled, it seems that what we actually want is to initialize its preempt_count to PREEMPT_DISABLED and leave it there. Do that, and remove init_idle() from idle_thread_get(). Secondary startups were patched via coccinelle: @begone@ @@ -preempt_disable(); ... cpu_startup_entry(CPUHP_AP_ONLINE_IDLE); Signed-off-by: Valentin Schneider <valentin.schneider@arm.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Link: https://lore.kernel.org/r/20210512094636.2958515-1-valentin.schneider@arm.com
2021-04-17powerpc/smp: Set numa node before updating maskGravatar Srikar Dronamraju 1-3/+3
Geethika reported a trace when doing a dlpar CPU add. ------------[ cut here ]------------ WARNING: CPU: 152 PID: 1134 at kernel/sched/topology.c:2057 CPU: 152 PID: 1134 Comm: kworker/152:1 Not tainted 5.12.0-rc5-master #5 Workqueue: events cpuset_hotplug_workfn NIP: c0000000001cfc14 LR: c0000000001cfc10 CTR: c0000000007e3420 REGS: c0000034a08eb260 TRAP: 0700 Not tainted (5.12.0-rc5-master+) MSR: 8000000000029033 <SF,EE,ME,IR,DR,RI,LE> CR: 28828422 XER: 00000020 CFAR: c0000000001fd888 IRQMASK: 0 #012GPR00: c0000000001cfc10 c0000034a08eb500 c000000001f35400 0000000000000027 #012GPR04: c0000035abaa8010 c0000035abb30a00 0000000000000027 c0000035abaa8018 #012GPR08: 0000000000000023 c0000035abaaef48 00000035aa540000 c0000035a49dffe8 #012GPR12: 0000000028828424 c0000035bf1a1c80 0000000000000497 0000000000000004 #012GPR16: c00000000347a258 0000000000000140 c00000000203d468 c000000001a1a490 #012GPR20: c000000001f9c160 c0000034adf70920 c0000034aec9fd20 0000000100087bd3 #012GPR24: 0000000100087bd3 c0000035b3de09f8 0000000000000030 c0000035b3de09f8 #012GPR28: 0000000000000028 c00000000347a280 c0000034aefe0b00 c0000000010a2a68 NIP [c0000000001cfc14] build_sched_domains+0x6a4/0x1500 LR [c0000000001cfc10] build_sched_domains+0x6a0/0x1500 Call Trace: [c0000034a08eb500] [c0000000001cfc10] build_sched_domains+0x6a0/0x1500 (unreliable) [c0000034a08eb640] [c0000000001d1e6c] partition_sched_domains_locked+0x3ec/0x530 [c0000034a08eb6e0] [c0000000002936d4] rebuild_sched_domains_locked+0x524/0xbf0 [c0000034a08eb7e0] [c000000000296bb0] rebuild_sched_domains+0x40/0x70 [c0000034a08eb810] [c000000000296e74] cpuset_hotplug_workfn+0x294/0xe20 [c0000034a08ebc30] [c000000000178dd0] process_one_work+0x300/0x670 [c0000034a08ebd10] [c0000000001791b8] worker_thread+0x78/0x520 [c0000034a08ebda0] [c000000000185090] kthread+0x1a0/0x1b0 [c0000034a08ebe10] [c00000000000ccec] ret_from_kernel_thread+0x5c/0x70 Instruction dump: 7d2903a6 4e800421 e8410018 7f67db78 7fe6fb78 7f45d378 7f84e378 7c681b78 3c62ff1a 3863c6f8 4802dc35 60000000 <0fe00000> 3920fff4 f9210070 e86100a0 ---[ end trace 532d9066d3d4d7ec ]--- Some of the per-CPU masks use cpu_cpu_mask as a filter to limit the search for related CPUs. On a dlpar add of a CPU, update cpu_cpu_mask before updating the per-CPU masks. This will ensure the cpu_cpu_mask is updated correctly before its used in setting the masks. Setting the numa_node will ensure that when cpu_cpu_mask() gets called, the correct node number is used. This code movement helped fix the above call trace. Reported-by: Geetika Moolchandani <Geetika.Moolchandani1@ibm.com> Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Reviewed-by: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210401154200.150077-1-srikar@linux.vnet.ibm.com
2021-04-17powerpc/smp: Cache CPU to chip lookupGravatar Srikar Dronamraju 1-2/+19
On systems with large CPUs per node, even with the filtered matching of related CPUs, there can be large number of calls to cpu_to_chip_id for the same CPU. For example with 4096 vCPU, 1 node QEMU configuration, with 4 threads per core, system could be see upto 1024 calls to cpu_to_chip_id() for the same CPU. On a given system, cpu_to_chip_id() for a given CPU would always return the same. Hence cache the result in a lookup table for use in subsequent calls. Since all CPUs sharing the same core will belong to the same chip, the lookup_table has an entry for one CPU per core. chip_id_lookup_table is not being freed and would be used on subsequent CPU online post CPU offline. Reported-by: Daniel Henrique Barboza <danielhb413@gmail.com> Suggested-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Tested-by: Daniel Henrique Barboza <danielhb413@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210415120934.232271-4-srikar@linux.vnet.ibm.com
2021-04-17powerpc/smp: Reintroduce cpu_core_maskGravatar Srikar Dronamraju 1-7/+32
Daniel reported that with Commit 4ca234a9cbd7 ("powerpc/smp: Stop updating cpu_core_mask") QEMU was unable to set single NUMA node SMP topologies such as: -smp 8,maxcpus=8,cores=2,threads=2,sockets=2 i.e he expected 2 sockets in one NUMA node. The above commit helped to reduce boot time on Large Systems for example 4096 vCPU single socket QEMU instance. PAPR is silent on having more than one socket within a NUMA node. cpu_core_mask and cpu_cpu_mask for any CPU would be same unless the number of sockets is different from the number of NUMA nodes. One option is to reintroduce cpu_core_mask but use a slightly different method to arrive at the cpu_core_mask. Previously each CPU's chip-id would be compared with all other CPU's chip-id to verify if both the CPUs were related at the chip level. Now if a CPU 'A' is found related / (unrelated) to another CPU 'B', all the thread siblings of 'A' and thread siblings of 'B' are automatically marked as related / (unrelated). Also if a platform doesn't support ibm,chip-id property, i.e its cpu_to_chip_id returns -1, cpu_core_map holds a copy of cpu_cpu_mask(). Fixes: 4ca234a9cbd7 ("powerpc/smp: Stop updating cpu_core_mask") Reported-by: Daniel Henrique Barboza <danielhb413@gmail.com> Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Tested-by: Daniel Henrique Barboza <danielhb413@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210415120934.232271-2-srikar@linux.vnet.ibm.com
2021-04-14powerpc/smp: Make some symbols staticGravatar Yu Kuai 1-3/+3
The sparse tool complains as follows: arch/powerpc/kernel/smp.c:86:1: warning: symbol '__pcpu_scope_cpu_coregroup_map' was not declared. Should it be static? arch/powerpc/kernel/smp.c:125:1: warning: symbol '__pcpu_scope_thread_group_l1_cache_map' was not declared. Should it be static? arch/powerpc/kernel/smp.c:132:1: warning: symbol '__pcpu_scope_thread_group_l2_cache_map' was not declared. Should it be static? These symbols are not used outside of smp.c, so this commit marks them static. Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210407125903.4139663-1-yukuai3@huawei.com