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  1. 25 Jul, 2019 1 commit
  3. 17 Jun, 2019 1 commit
    • Peter Zijlstra's avatar
      x86/percpu: Relax smp_processor_id() · 9ed7d75b
      Peter Zijlstra authored 
      

Nadav reported that since this_cpu_read() became asm-volatile, many
smp_processor_id() users generated worse code due to the extra
constraints.

However since smp_processor_id() is reading a stable value, we can use
__this_cpu_read().

While this does reduce text size somewhat, this mostly results in code
movement to .text.unlikely as a result of more/larger .cold.
subfunctions. Less text on the hotpath is good for I$.

  $ ./compare.sh defconfig-build1 defconfig-build2 vmlinux.o
  setup_APIC_ibs                                             90         98   -12,+20
  force_ibs_eilvt_setup                                     400        413   -57,+70
  pci_serr_error                                            109        104   -54,+49
  pci_serr_error                                            109        104   -54,+49
  unknown_nmi_error                                         125        120   -76,+71
  unknown_nmi_error                                         125        120   -76,+71
  io_check_error                                            125        132   -97,+104
  intel_thermal_interrupt                                   730        822   +92,+0
  intel_init_thermal                                        951        945   -6,+0
  generic_get_mtrr                                          301        294   -7,+0
  generic_get_mtrr                                          301        294   -7,+0
  generic_set_all                                           749        754   -44,+49
  get_fixed_ranges                                          352        360   -41,+49
  x86_acpi_suspend_lowlevel                                 369        363   -6,+0
  check_tsc_sync_source                                     412        412   -71,+71
  irq_migrate_all_off_this_cpu                              662        674   -14,+26
  clocksource_watchdog                                      748        748   -113,+113
  __perf_event_account_interrupt                            204        197   -7,+0
  attempt_merge                                            1748       1741   -7,+0
  intel_guc_send_ct                                        1424       1409   -15,+0
  __fini_doorbell                                           235        231   -4,+0
  bdw_set_cdclk                                             928        923   -5,+0
  gen11_dsi_disable                                        1571       1556   -15,+0
  gmbus_wait                                                493        488   -5,+0
  md_make_request                                           376        369   -7,+0
  __split_and_process_bio                                   543        536   -7,+0
  delay_tsc                                                  96         89   -7,+0
  hsw_disable_pc8                                           696        691   -5,+0
  tsc_verify_tsc_adjust                                     215        228   -22,+35
  cpuidle_driver_unref                                       56         49   -7,+0
  blk_account_io_completion                                 159        148   -11,+0
  mtrr_wrmsr                                                 95         99   -29,+33
  __intel_wait_for_register_fw                              401        419   +18,+0
  cpuidle_driver_ref                                         43         36   -7,+0
  cpuidle_get_driver                                         15          8   -7,+0
  blk_account_io_done                                       535        528   -7,+0
  irq_migrate_all_off_this_cpu                              662        674   -14,+26
  check_tsc_sync_source                                     412        412   -71,+71
  irq_wait_for_poll                                         170        163   -7,+0
  generic_end_io_acct                                       329        322   -7,+0
  x86_acpi_suspend_lowlevel                                 369        363   -6,+0
  nohz_balance_enter_idle                                   198        191   -7,+0
  generic_start_io_acct                                     254        247   -7,+0
  blk_account_io_start                                      341        334   -7,+0
  perf_event_task_tick                                      682        675   -7,+0
  intel_init_thermal                                        951        945   -6,+0
  amd_e400_c1e_apic_setup                                    47         51   -28,+32
  setup_APIC_eilvt                                          350        328   -22,+0
  hsw_enable_pc8                                           1611       1605   -6,+0
                                               total   12985947   12985892   -994,+939
Reported-by: default avatarNadav Amit <nadav.amit@gmail.com>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      9ed7d75b
  5. 23 May, 2019 1 commit
  7. 17 Apr, 2019 1 commit
    • Thomas Gleixner's avatar
      x86/irq/32: Handle irq stack allocation failure proper · 66c7ceb4
      Thomas Gleixner authored 
      

irq_ctx_init() crashes hard on page allocation failures. While that's ok
during early boot, it's just wrong in the CPU hotplug bringup code.

Check the page allocation failure and return -ENOMEM and handle it at the
call sites. On early boot the only way out is to BUG(), but on CPU hotplug
there is no reason to crash, so just abort the operation.

Rename the function to something more sensible while at it.
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
Cc: Alison Schofield <alison.schofield@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Nicolai Stange <nstange@suse.de>
Cc: Pu Wen <puwen@hygon.cn>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: Shaokun Zhang <zhangshaokun@hisilicon.com>
Cc: Stefano Stabellini <sstabellini@kernel.org>
Cc: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Cc: x86-ml <x86@kernel.org>
Cc: xen-devel@lists.xenproject.org
Cc: Yazen Ghannam <yazen.ghannam@amd.com>
Cc: Yi Wang <wang.yi59@zte.com.cn>
Cc: Zhenzhong Duan <zhenzhong.duan@oracle.com>
Link: https://lkml.kernel.org/r/20190414160146.089060584@linutronix.de
      66c7ceb4
  9. 23 Nov, 2018 1 commit
    • Yi Wang's avatar
      x86/headers: Fix -Wmissing-prototypes warning · 89f579ce
      Yi Wang authored 
      

When building the kernel with W=1 we get a lot of -Wmissing-prototypes
warnings, which are trivial in nature and easy to fix - and which may
mask some real future bugs if the prototypes get out of sync with
the function definition.

This patch fixes most of -Wmissing-prototypes warnings which
are in the root directory of arch/x86/kernel, not including
the subdirectories.

These are the warnings fixed in this patch:

  arch/x86/kernel/signal.c:865:17: warning: no previous prototype for ‘sys32_x32_rt_sigreturn’ [-Wmissing-prototypes]
  arch/x86/kernel/signal_compat.c:164:6: warning: no previous prototype for ‘sigaction_compat_abi’ [-Wmissing-prototypes]
  arch/x86/kernel/traps.c:625:46: warning: no previous prototype for ‘sync_regs’ [-Wmissing-prototypes]
  arch/x86/kernel/traps.c:640:24: warning: no previous prototype for ‘fixup_bad_iret’ [-Wmissing-prototypes]
  arch/x86/kernel/traps.c:929:13: warning: no previous prototype for ‘trap_init’ [-Wmissing-prototypes]
  arch/x86/kernel/irq.c:270:28: warning: no previous prototype for ‘smp_x86_platform_ipi’ [-Wmissing-prototypes]
  arch/x86/kernel/irq.c:301:16: warning: no previous prototype for ‘smp_kvm_posted_intr_ipi’ [-Wmissing-prototypes]
  arch/x86/kernel/irq.c:314:16: warning: no previous prototype for ‘smp_kvm_posted_intr_wakeup_ipi’ [-Wmissing-prototypes]
  arch/x86/kernel/irq.c:328:16: warning: no previous prototype for ‘smp_kvm_posted_intr_nested_ipi’ [-Wmissing-prototypes]
  arch/x86/kernel/irq_work.c:16:28: warning: no previous prototype for ‘smp_irq_work_interrupt’ [-Wmissing-prototypes]
  arch/x86/kernel/irqinit.c:79:13: warning: no previous prototype for ‘init_IRQ’ [-Wmissing-prototypes]
  arch/x86/kernel/quirks.c:672:13: warning: no previous prototype for ‘early_platform_quirks’ [-Wmissing-prototypes]
  arch/x86/kernel/tsc.c:1499:15: warning: no previous prototype for ‘calibrate_delay_is_known’ [-Wmissing-prototypes]
  arch/x86/kernel/process.c:653:13: warning: no previous prototype for ‘arch_post_acpi_subsys_init’ [-Wmissing-prototypes]
  arch/x86/kernel/process.c:717:15: warning: no previous prototype for ‘arch_randomize_brk’ [-Wmissing-prototypes]
  arch/x86/kernel/process.c:784:6: warning: no previous prototype for ‘do_arch_prctl_common’ [-Wmissing-prototypes]
  arch/x86/kernel/reboot.c:869:6: warning: no previous prototype for ‘nmi_panic_self_stop’ [-Wmissing-prototypes]
  arch/x86/kernel/smp.c:176:27: warning: no previous prototype for ‘smp_reboot_interrupt’ [-Wmissing-prototypes]
  arch/x86/kernel/smp.c:260:28: warning: no previous prototype for ‘smp_reschedule_interrupt’ [-Wmissing-prototypes]
  arch/x86/kernel/smp.c:281:28: warning: no previous prototype for ‘smp_call_function_interrupt’ [-Wmissing-prototypes]
  arch/x86/kernel/smp.c:291:28: warning: no previous prototype for ‘smp_call_function_single_interrupt’ [-Wmissing-prototypes]
  arch/x86/kernel/ftrace.c:840:6: warning: no previous prototype for ‘arch_ftrace_update_trampoline’ [-Wmissing-prototypes]
  arch/x86/kernel/ftrace.c:934:7: warning: no previous prototype for ‘arch_ftrace_trampoline_func’ [-Wmissing-prototypes]
  arch/x86/kernel/ftrace.c:946:6: warning: no previous prototype for ‘arch_ftrace_trampoline_free’ [-Wmissing-prototypes]
  arch/x86/kernel/crash.c:114:6: warning: no previous prototype for ‘crash_smp_send_stop’ [-Wmissing-prototypes]
  arch/x86/kernel/crash.c:351:5: warning: no previous prototype for ‘crash_setup_memmap_entries’ [-Wmissing-prototypes]
  arch/x86/kernel/crash.c:424:5: warning: no previous prototype for ‘crash_load_segments’ [-Wmissing-prototypes]
  arch/x86/kernel/machine_kexec_64.c:372:7: warning: no previous prototype for ‘arch_kexec_kernel_image_load’ [-Wmissing-prototypes]
  arch/x86/kernel/paravirt-spinlocks.c:12:16: warning: no previous prototype for ‘__native_queued_spin_unlock’ [-Wmissing-prototypes]
  arch/x86/kernel/paravirt-spinlocks.c:18:6: warning: no previous prototype for ‘pv_is_native_spin_unlock’ [-Wmissing-prototypes]
  arch/x86/kernel/paravirt-spinlocks.c:24:16: warning: no previous prototype for ‘__native_vcpu_is_preempted’ [-Wmissing-prototypes]
  arch/x86/kernel/paravirt-spinlocks.c:30:6: warning: no previous prototype for ‘pv_is_native_vcpu_is_preempted’ [-Wmissing-prototypes]
  arch/x86/kernel/kvm.c:258:1: warning: no previous prototype for ‘do_async_page_fault’ [-Wmissing-prototypes]
  arch/x86/kernel/jailhouse.c:200:6: warning: no previous prototype for ‘jailhouse_paravirt’ [-Wmissing-prototypes]
  arch/x86/kernel/check.c:91:13: warning: no previous prototype for ‘setup_bios_corruption_check’ [-Wmissing-prototypes]
  arch/x86/kernel/check.c:139:6: warning: no previous prototype for ‘check_for_bios_corruption’ [-Wmissing-prototypes]
  arch/x86/kernel/devicetree.c:32:13: warning: no previous prototype for ‘early_init_dt_scan_chosen_arch’ [-Wmissing-prototypes]
  arch/x86/kernel/devicetree.c:42:13: warning: no previous prototype for ‘add_dtb’ [-Wmissing-prototypes]
  arch/x86/kernel/devicetree.c:108:6: warning: no previous prototype for ‘x86_of_pci_init’ [-Wmissing-prototypes]
  arch/x86/kernel/devicetree.c:314:13: warning: no previous prototype for ‘x86_dtb_init’ [-Wmissing-prototypes]
  arch/x86/kernel/tracepoint.c:16:5: warning: no previous prototype for ‘trace_pagefault_reg’ [-Wmissing-prototypes]
  arch/x86/kernel/tracepoint.c:22:6: warning: no previous prototype for ‘trace_pagefault_unreg’ [-Wmissing-prototypes]
  arch/x86/kernel/head64.c:113:22: warning: no previous prototype for ‘__startup_64’ [-Wmissing-prototypes]
  arch/x86/kernel/head64.c:262:15: warning: no previous prototype for ‘__startup_secondary_64’ [-Wmissing-prototypes]
  arch/x86/kernel/head64.c:350:12: warning: no previous prototype for ‘early_make_pgtable’ [-Wmissing-prototypes]

[ mingo: rewrote the changelog, fixed build errors. ]
Signed-off-by: default avatarYi Wang <wang.yi59@zte.com.cn>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: akataria@vmware.com
Cc: akpm@linux-foundation.org
Cc: andy.shevchenko@gmail.com
Cc: anton@enomsg.org
Cc: ard.biesheuvel@linaro.org
Cc: bhe@redhat.com
Cc: bhelgaas@google.com
Cc: bp@alien8.de
Cc: ccross@android.com
Cc: devicetree@vger.kernel.org
Cc: douly.fnst@cn.fujitsu.com
Cc: dwmw@amazon.co.uk
Cc: dyoung@redhat.com
Cc: ebiederm@xmission.com
Cc: frank.rowand@sony.com
Cc: frowand.list@gmail.com
Cc: ivan.gorinov@intel.com
Cc: jailhouse-dev@googlegroups.com
Cc: jan.kiszka@siemens.com
Cc: jgross@suse.com
Cc: jroedel@suse.de
Cc: keescook@chromium.org
Cc: kexec@lists.infradead.org
Cc: konrad.wilk@oracle.com
Cc: kvm@vger.kernel.org
Cc: linux-efi@vger.kernel.org
Cc: linux-pci@vger.kernel.org
Cc: luto@kernel.org
Cc: m.mizuma@jp.fujitsu.com
Cc: namit@vmware.com
Cc: oleg@redhat.com
Cc: pasha.tatashin@oracle.com
Cc: pbonzini@redhat.com
Cc: prarit@redhat.com
Cc: pravin.shedge4linux@gmail.com
Cc: rajvi.jingar@intel.com
Cc: rkrcmar@redhat.com
Cc: robh+dt@kernel.org
Cc: robh@kernel.org
Cc: rostedt@goodmis.org
Cc: takahiro.akashi@linaro.org
Cc: thomas.lendacky@amd.com
Cc: tony.luck@intel.com
Cc: up2wing@gmail.com
Cc: virtualization@lists.linux-foundation.org
Cc: zhe.he@windriver.com
Cc: zhong.weidong@zte.com.cn
Link: http://lkml.kernel.org/r/1542852249-19820-1-git-send-email-wang.yi59@zte.com.cn

Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      89f579ce
  11. 06 May, 2018 1 commit
  13. 01 Mar, 2018 1 commit
  15. 17 Feb, 2018 1 commit
    • Prarit Bhargava's avatar
      x86/xen: Calculate __max_logical_packages on PV domains · 63e708f8
      Prarit Bhargava authored 
      The kernel panics on PV domains because native_smp_cpus_done() is
only called for HVM domains.

Calculate __max_logical_packages for PV domains.

Fixes: b4c0a732

 ("x86/smpboot: Fix __max_logical_packages estimate")
Signed-off-by: default avatarPrarit Bhargava <prarit@redhat.com>
Tested-and-reported-by: default avatarSimon Gaiser <simon@invisiblethingslab.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: x86@kernel.org
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Dou Liyang <douly.fnst@cn.fujitsu.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: xen-devel@lists.xenproject.org
Reviewed-by: default avatarBoris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: default avatarJuergen Gross <jgross@suse.com>
      63e708f8
  17. 02 Nov, 2017 1 commit
    • Greg Kroah-Hartman's avatar
      License cleanup: add SPDX GPL-2.0 license identifier to files with no license · b2441318
      Greg Kroah-Hartman authored 
      

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier.  The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
 - file had no licensing information it it.
 - file was a */uapi/* one with no licensing information in it,
 - file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne.  Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed.  Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
 - Files considered eligible had to be source code files.
 - Make and config files were included as candidates if they contained >5
   lines of source
 - File already had some variant of a license header in it (even if <5
   lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

 - when both scanners couldn't find any license traces, file was
   considered to have no license information in it, and the top level
   COPYING file license applied.

   For non */uapi/* files that summary was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0                                              11139

   and resulted in the first patch in this series.

   If that file was a */uapi/* path one, it was "GPL-2.0 WITH
   Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0 WITH Linux-syscall-note                        930

   and resulted in the second patch in this series.

 - if a file had some form of licensing information in it, and was one
   of the */uapi/* ones, it was denoted with the Linux-syscall-note if
   any GPL family license was found in the file or had no licensing in
   it (per prior point).  Results summary:

   SPDX license identifier                            # files
   ---------------------------------------------------|------
   GPL-2.0 WITH Linux-syscall-note                       270
   GPL-2.0+ WITH Linux-syscall-note                      169
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
   LGPL-2.1+ WITH Linux-syscall-note                      15
   GPL-1.0+ WITH Linux-syscall-note                       14
   ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
   LGPL-2.0+ WITH Linux-syscall-note                       4
   LGPL-2.1 WITH Linux-syscall-note                        3
   ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
   ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1

   and that resulted in the third patch in this series.

 - when the two scanners agreed on the detected license(s), that became
   the concluded license(s).

 - when there was disagreement between the two scanners (one detected a
   license but the other didn't, or they both detected different
   licenses) a manual inspection of the file occurred.

 - In most cases a manual inspection of the information in the file
   resulted in a clear resolution of the license that should apply (and
   which scanner probably needed to revisit its heuristics).

 - When it was not immediately clear, the license identifier was
   confirmed with lawyers working with the Linux Foundation.

 - If there was any question as to the appropriate license identifier,
   the file was flagged for further research and to be revisited later
   in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights.  The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
 - a full scancode scan run, collecting the matched texts, detected
   license ids and scores
 - reviewing anything where there was a license detected (about 500+
   files) to ensure that the applied SPDX license was correct
 - reviewing anything where there was no detection but the patch license
   was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
   SPDX license was correct

This produced a worksheet with 20 files needing minor correction.  This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg.  Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected.  This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.)  Finally Greg ran the script using the .csv files to
generate the patches.
Reviewed-by: default avatarKate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: default avatarPhilippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: default avatarThomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      b2441318
  19. 14 Apr, 2017 2 commits
  21. 11 Oct, 2016 1 commit
    • Hidehiro Kawai's avatar
      x86/panic: replace smp_send_stop() with kdump friendly version in panic path · 0ee59413
      Hidehiro Kawai authored 
      Daniel Walker reported problems which happens when
crash_kexec_post_notifiers kernel option is enabled
(https://lkml.org/lkml/2015/6/24/44).

In that case, smp_send_stop() is called before entering kdump routines
which assume other CPUs are still online.  As the result, for x86, kdump
routines fail to save other CPUs' registers and disable virtualization
extensions.

To fix this problem, call a new kdump friendly function,
crash_smp_send_stop(), instead of the smp_send_stop() when
crash_kexec_post_notifiers is enabled.  crash_smp_send_stop() is a weak
function, and it just call smp_send_stop().  Architecture codes should
override it so that kdump can work appropriately.  This patch only
provides x86-specific version.

For Xen's PV kernel, just keep the current behavior.

NOTES:

- Right solution would be to place crash_smp_send_stop() before
  __crash_kexec() invocation in all cases and remove smp_send_stop(), but
  we can't do that until all architectures implement own
  crash_smp_send_stop()

- crash_smp_send_stop()-like work is still needed by
  machine_crash_shutdown() because crash_kexec() can be called without
  entering panic()

Fixes: f06e5153 (kernel/panic.c: add "crash_kexec_post_notifiers" option)
Link: http://lkml.kernel.org/r/20160810080948.11028.15344.stgit@sysi4-13.yrl.intra.hitachi.co.jp

Signed-off-by: default avatarHidehiro Kawai <hidehiro.kawai.ez@hitachi.com>
Reported-by: default avatarDaniel Walker <dwalker@fifo99.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Daniel Walker <dwalker@fifo99.com>
Cc: Xunlei Pang <xpang@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: Toshi Kani <toshi.kani@hpe.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: David Daney <david.daney@cavium.com>
Cc: Aaro Koskinen <aaro.koskinen@iki.fi>
Cc: "Steven J. Hill" <steven.hill@cavium.com>
Cc: Corey Minyard <cminyard@mvista.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      0ee59413
  23. 18 Aug, 2016 1 commit
    • Josh Poimboeuf's avatar
      x86/asm/head: Rename 'stack_start' -> 'initial_stack' · b32f96c7
      Josh Poimboeuf authored 
      

The 'stack_start' variable is similar in usage to 'initial_code' and
'initial_gs': they're all stored in head_64.S and they're all updated by
SMP and ACPI suspend before starting a CPU.

Rename it to 'initial_stack' to be consistent with the others.
Signed-off-by: default avatarJosh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Byungchul Park <byungchul.park@lge.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Nilay Vaish <nilayvaish@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/87063d773a3212051b77e17b0ee427f6582a5050.1471535549.git.jpoimboe@redhat.com

Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      b32f96c7
  25. 25 Jul, 2016 1 commit
  27. 15 Jul, 2016 2 commits
    • Rafael J. Wysocki's avatar
      x86 / hibernate: Use hlt_play_dead() when resuming from hibernation · 406f992e
      Rafael J. Wysocki authored 
      On Intel hardware, native_play_dead() uses mwait_play_dead() by
default and only falls back to the other methods if that fails.
That also happens during resume from hibernation, when the restore
(boot) kernel runs disable_nonboot_cpus() to take all of the CPUs
except for the boot one offline.

However, that is problematic, because the address passed to
__monitor() in mwait_play_dead() is likely to be written to in the
last phase of hibernate image restoration and that causes the "dead"
CPU to start executing instructions again.  Unfortunately, the page
containing the address in that CPU's instruction pointer may not be
valid any more at that point.

First, that page may have been overwritten with image kernel memory
contents already, so the instructions the CPU attempts to execute may
simply be invalid.  Second, the page tables previously used by that
CPU may have been overwritten by image kernel memory contents, so the
address in its instruction pointer is impossible to resolve then.

A report from Varun Koyyalagunta and investigation carried out by
Chen Yu show that the latter sometimes happens in practice.

To prevent it from happening, temporarily change the smp_ops.play_dead
pointer during resume from hibernation so that it points to a special
"play dead" routine which uses hlt_play_dead() and avoids the
inadvertent "revivals" of "dead" CPUs this way.

A slightly unpleasant consequence of this change is that if the
system is hibernated with one or more CPUs offline, it will generally
draw more power after resume than it did before hibernation, because
the physical state entered by CPUs via hlt_play_dead() is higher-power
than the mwait_play_dead() one in the majority of cases.  It is
possible to work around this, but it is unclear how much of a problem
that's going to be in practice, so the workaround will be implemented
later if it turns out to be necessary.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=106371

Reported-by: default avatarVarun Koyyalagunta <cpudebug@centtech.com>
Original-by: default avatarChen Yu <yu.c.chen@intel.com>
Tested-by: default avatarChen Yu <yu.c.chen@intel.com>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: default avatarIngo Molnar <mingo@kernel.org>
      406f992e
    • Andy Lutomirski's avatar
      x86/smp: Remove stack_smp_processor_id() · fb59831b
      Andy Lutomirski authored 
      

It serves no purpose -- raw_smp_processor_id() works fine.  This
change will be needed to move thread_info off the stack.
Signed-off-by: default avatarAndy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/a2bf4f07fbc30fb32f9f7f3f8f94ad3580823847.1468527351.git.luto@kernel.org

Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      fb59831b
  29. 29 Mar, 2016 1 commit
  31. 30 Jan, 2016 1 commit
  33. 19 Nov, 2015 1 commit
  35. 17 Nov, 2015 1 commit
  37. 27 May, 2015 1 commit
  39. 02 Apr, 2015 1 commit
  41. 11 Mar, 2015 1 commit
    • Paul E. McKenney's avatar
      x86: Use common outgoing-CPU-notification code · 2a442c9c
      Paul E. McKenney authored 
      

This commit removes the open-coded CPU-offline notification with new
common code.  Among other things, this change avoids calling scheduler
code using RCU from an offline CPU that RCU is ignoring.  It also allows
Xen to notice at online time that the CPU did not go offline correctly.
Note that Xen has the surviving CPU carry out some cleanup operations,
so if the surviving CPU times out, these cleanup operations might have
been carried out while the outgoing CPU was still running.  It might
therefore be unwise to bring this CPU back online, and this commit
avoids doing so.
Signed-off-by: default avatarBoris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: default avatarPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: <x86@kernel.org>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: <xen-devel@lists.xenproject.org>
      2a442c9c
  43. 10 Nov, 2014 1 commit
  45. 07 Jan, 2014 1 commit
  47. 14 Jul, 2013 1 commit
    • Paul Gortmaker's avatar
      x86: delete __cpuinit usage from all x86 files · 148f9bb8
      Paul Gortmaker authored 
      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 5e427ec2 ("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/x86 uses of the __cpuinit macros from
all C files.  x86 only had the one __CPUINIT used in assembly files,
and it wasn't paired off with a .previous or a __FINIT, so we can
delete it directly w/o any corresponding additional change there.

[1] https://lkml.org/lkml/2013/5/20/589



Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: x86@kernel.org
Acked-by: default avatarIngo Molnar <mingo@kernel.org>
Acked-by: default avatarThomas Gleixner <tglx@linutronix.de>
Acked-by: default avatarH. Peter Anvin <hpa@linux.intel.com>
Signed-off-by: default avatarPaul Gortmaker <paul.gortmaker@windriver.com>
      148f9bb8
  49. 14 Nov, 2012 1 commit
  51. 14 Jun, 2012 1 commit
    • Vlad Zolotarov's avatar
      x86: Add read_mostly declaration/definition to variables from smp.h · 0816b0f0
      Vlad Zolotarov authored 
      

Add "read-mostly" qualifier to the following variables in
smp.h:

 - cpu_sibling_map
 - cpu_core_map
 - cpu_llc_shared_map
 - cpu_llc_id
 - cpu_number
 - x86_cpu_to_apicid
 - x86_bios_cpu_apicid
 - x86_cpu_to_logical_apicid

As long as all the variables above are only written during the
initialization, this change is meant to prevent the false
sharing. More specifically, on vSMP Foundation platform
x86_cpu_to_apicid shared the same internode_cache_line with
frequently written lapic_events.

From the analysis of the first 33 per_cpu variables out of 219
(memories they describe, to be more specific) the 8 have read_mostly
nature (tlb_vector_offset, cpu_loops_per_jiffy, xen_debug_irq, etc.)
and 25 are frequently written (irq_stack_union, gdt_page,
exception_stacks, idt_desc, etc.).

Assuming that the spread of the rest of the per_cpu variables is
similar, identifying the read mostly memories will make more sense
in terms of long-term code maintenance comparing to identifying
frequently written memories.
Signed-off-by: default avatarVlad Zolotarov <vlad@scalemp.com>
Acked-by: default avatarShai Fultheim <shai@scalemp.com>
Cc: Shai Fultheim (Shai@ScaleMP.com) <Shai@scalemp.com>
Cc: ido@wizery.com
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1719258.EYKzE4Zbq5@vlad

Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      0816b0f0
  53. 05 Jun, 2012 1 commit
  55. 14 May, 2012 1 commit
  57. 26 Apr, 2012 3 commits
  59. 05 Dec, 2011 1 commit
    • Don Zickus's avatar
      x86, NMI: Add NMI IPI selftest · 99e8b9ca
      Don Zickus authored 
      

The previous patch modified the stop cpus path to use NMI
instead of IRQ as the way to communicate to the other cpus to
shutdown.  There were some concerns that various machines may
have problems with using an NMI IPI.

This patch creates a selftest to check if NMI is working at
boot. The idea is to help catch any issues before the machine
panics and we learn the hard way.

Loosely based on the locking-selftest.c file, this separate file
runs a couple of simple tests and reports the results.  The
output looks like:

...
Brought up 4 CPUs
----------------
| NMI testsuite:
--------------------
  remote IPI:  ok  |
   local IPI:  ok  |
--------------------
Good, all   2 testcases passed! |
---------------------------------
Total of 4 processors activated (21330.61 BogoMIPS).
...
Signed-off-by: default avatarDon Zickus <dzickus@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Robert Richter <robert.richter@amd.com>
Cc: seiji.aguchi@hds.com
Cc: vgoyal@redhat.com
Cc: mjg@redhat.com
Cc: tony.luck@intel.com
Cc: gong.chen@intel.com
Cc: satoru.moriya@hds.com
Cc: avi@redhat.com
Cc: Andi Kleen <andi@firstfloor.org>
Link: http://lkml.kernel.org/r/1318533267-18880-3-git-send-email-dzickus@redhat.com

Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      99e8b9ca
  61. 05 Mar, 2011 1 commit
  63. 05 Feb, 2011 1 commit
  65. 28 Jan, 2011 2 commits
    • Tejun Heo's avatar
      x86: Fix build failure on X86_UP_APIC · 4e62445b
      Tejun Heo authored 
      Commit 4c321ff8

 (x86: Replace cpu_2_logical_apicid[] with early
percpu variable) and following changes introduced and used
x86_cpu_to_logical_apicid percpu variable.  It was declared and
defined inside CONFIG_SMP && CONFIG_X86_32 but if
CONFIG_X86_UP_APIC is set UP configuration makes use of it and
build fails.

Fix it by declaring and defining it inside CONFIG_X86_LOCAL_APIC
&& CONFIG_X86_32.
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Reported-by: default avatarIngo Molnar <mingo@elte.hu>
Cc: eric.dumazet@gmail.com
Cc: yinghai@kernel.org
Cc: brgerst@gmail.com
Cc: gorcunov@gmail.com
Cc: penberg@kernel.org
Cc: shaohui.zheng@intel.com
Cc: rientjes@google.com
LKML-Reference: <20110128162248.GA25746@htj.dyndns.org>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      4e62445b
    • Tejun Heo's avatar
      x86: Replace cpu_2_logical_apicid[] with early percpu variable · 4c321ff8
      Tejun Heo authored 
      

Unlike x86_64, on x86_32, the mapping from cpu to logical apicid
may vary depending on apic in use.  cpu_2_logical_apicid[] array
is used for this mapping.  Replace it with early percpu variable
x86_cpu_to_logical_apicid to make it better aligned with other
mappings.
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Cc: eric.dumazet@gmail.com
Cc: yinghai@kernel.org
Cc: brgerst@gmail.com
Cc: gorcunov@gmail.com
Cc: penberg@kernel.org
Cc: shaohui.zheng@intel.com
Cc: rientjes@google.com
LKML-Reference: <1295789862-25482-5-git-send-email-tj@kernel.org>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      4c321ff8
  67. 26 Jan, 2011 1 commit
    • Yinghai Lu's avatar
      x86: Move llc_shared_map out of cpu_info · b3d7336d
      Yinghai Lu authored 
      

cpu_info is already with per_cpu, We can take llc_shared_map out
of cpu_info, and declare it as per_cpu variable directly.

So later referencing could be simple and directly instead of
diving to find cpu_info at first.

Also could make smp_store_cpu_info() much simple to avoid to do
save and restore trick.
Signed-off-by: default avatarYinghai Lu <yinghai@kernel.org>
Cc: Hans Rosenfeld <hans.rosenfeld@amd.com>
Cc: Alok N Kataria <akataria@vmware.com>
Cc: Stephen Hemminger <shemminger@vyatta.com>
Cc: Hans J. Koch <hjk@linutronix.de>
Cc: Tejun Heo <tj@kernel.org>
Cc: Borislav Petkov <borislav.petkov@amd.com>
Cc: Andreas Herrmann <andreas.herrmann3@amd.com>
Cc: Robert Richter <robert.richter@amd.com>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
LKML-Reference: <4D3A16E8.5020608@kernel.org>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      b3d7336d
  69. 21 Oct, 2010 1 commit
    • Alok Kataria's avatar
      x86, kexec: Make sure to stop all CPUs before exiting the kernel · 76fac077
      Alok Kataria authored 
      x86 smp_ops now has a new op, stop_other_cpus which takes a parameter
"wait" this allows the caller to specify if it wants to stop until all
the cpus have processed the stop IPI.  This is required specifically
for the kexec case where we should wait for all the cpus to be stopped
before starting the new kernel.  We now wait for the cpus to stop in
all cases except for panic/kdump where we expect things to be broken
and we are doing our best to make things work anyway.

This patch fixes a legitimate regression, which was introduced during
2.6.30, by commit id 4ef702c1

.
Signed-off-by: default avatarAlok N Kataria <akataria@vmware.com>
LKML-Reference: <1286833028.1372.20.camel@ank32.eng.vmware.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: <stable@kernel.org> v2.6.30-36
Signed-off-by: default avatarH. Peter Anvin <hpa@linux.intel.com>
      76fac077