1. 01 Jun, 2017 1 commit
  2. 31 May, 2017 2 commits
    • Imre Deak's avatar
      drm/i915: Prevent the system suspend complete optimization · adfdf85d
      Imre Deak authored
      Since
      
      commit bac2a909
      Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
      Date:   Wed Jan 21 02:17:42 2015 +0100
      
          PCI / PM: Avoid resuming PCI devices during system suspend
      
      PCI devices will default to allowing the system suspend complete
      optimization where devices are not woken up during system suspend if
      they were already runtime suspended. This however breaks the i915/HDA
      drivers for two reasons:
      
      - The i915 driver has system suspend specific steps that it needs to
        run, that bring the device to a different state than its runtime
        suspended state.
      
      - The HDA driver's suspend handler requires power that it will request
        from the i915 driver's power domain handler. This in turn requires the
        i915 driver to runtime resume itself, but this won't be possible if the
        suspend complete optimization is in effect: in this case the i915
        runtime PM is disabled and trying to get an RPM reference returns
        -EACCESS.
      
      Solve this by requiring the PCI/PM core to resume the device during
      system suspend which in effect disables the suspend complete optimization.
      
      Regardless of the above commit the optimization stayed disabled for DRM
      devices until
      
      commit d14d2a84
      Author: Lukas Wunner <lukas@wunner.de>
      Date:   Wed Jun 8 12:49:29 2016 +0200
      
          drm: Remove dev_pm_ops from drm_class
      
      so this patch is in practice a fix for this commit. Another reason for
      the bug staying hidden for so long is that the optimization for a device
      is disabled if it's disabled for any of its children devices. i915 may
      have a backlight device as its child which doesn't support runtime PM
      and so doesn't allow the optimization either.  So if this backlight
      device got registered the bug stayed hidden.
      
      Credits to Marta, Tomi and David who enabled pstore logging,
      that caught one instance of this issue across a suspend/
      resume-to-ram and Ville who rememberd that the optimization was enabled
      for some devices at one point.
      
      The first WARN triggered by the problem:
      
      [ 6250.746445] WARNING: CPU: 2 PID: 17384 at drivers/gpu/drm/i915/intel_runtime_pm.c:2846 intel_runtime_pm_get+0x6b/0xd0 [i915]
      [ 6250.746448] pm_runtime_get_sync() failed: -13
      [ 6250.746451] Modules linked in: snd_hda_intel i915 vgem snd_hda_codec_hdmi x86_pkg_temp_thermal intel_powerclamp coretemp crct10dif_pclmul crc32_pclmul
      snd_hda_codec_realtek snd_hda_codec_generic ghash_clmulni_intel e1000e snd_hda_codec snd_hwdep snd_hda_core ptp mei_me pps_core snd_pcm lpc_ich mei prime_
      numbers i2c_hid i2c_designware_platform i2c_designware_core [last unloaded: i915]
      [ 6250.746512] CPU: 2 PID: 17384 Comm: kworker/u8:0 Tainted: G     U  W       4.11.0-rc5-CI-CI_DRM_334+ #1
      [ 6250.746515] Hardware name:                  /NUC5i5RYB, BIOS RYBDWi35.86A.0362.2017.0118.0940 01/18/2017
      [ 6250.746521] Workqueue: events_unbound async_run_entry_fn
      [ 6250.746525] Call Trace:
      [ 6250.746530]  dump_stack+0x67/0x92
      [ 6250.746536]  __warn+0xc6/0xe0
      [ 6250.746542]  ? pci_restore_standard_config+0x40/0x40
      [ 6250.746546]  warn_slowpath_fmt+0x46/0x50
      [ 6250.746553]  ? __pm_runtime_resume+0x56/0x80
      [ 6250.746584]  intel_runtime_pm_get+0x6b/0xd0 [i915]
      [ 6250.746610]  intel_display_power_get+0x1b/0x40 [i915]
      [ 6250.746646]  i915_audio_component_get_power+0x15/0x20 [i915]
      [ 6250.746654]  snd_hdac_display_power+0xc8/0x110 [snd_hda_core]
      [ 6250.746661]  azx_runtime_resume+0x218/0x280 [snd_hda_intel]
      [ 6250.746667]  pci_pm_runtime_resume+0x76/0xa0
      [ 6250.746672]  __rpm_callback+0xb4/0x1f0
      [ 6250.746677]  ? pci_restore_standard_config+0x40/0x40
      [ 6250.746682]  rpm_callback+0x1f/0x80
      [ 6250.746686]  ? pci_restore_standard_config+0x40/0x40
      [ 6250.746690]  rpm_resume+0x4ba/0x740
      [ 6250.746698]  __pm_runtime_resume+0x49/0x80
      [ 6250.746703]  pci_pm_suspend+0x57/0x140
      [ 6250.746709]  dpm_run_callback+0x6f/0x330
      [ 6250.746713]  ? pci_pm_freeze+0xe0/0xe0
      [ 6250.746718]  __device_suspend+0xf9/0x370
      [ 6250.746724]  ? dpm_watchdog_set+0x60/0x60
      [ 6250.746730]  async_suspend+0x1a/0x90
      [ 6250.746735]  async_run_entry_fn+0x34/0x160
      [ 6250.746741]  process_one_work+0x1f2/0x6d0
      [ 6250.746749]  worker_thread+0x49/0x4a0
      [ 6250.746755]  kthread+0x107/0x140
      [ 6250.746759]  ? process_one_work+0x6d0/0x6d0
      [ 6250.746763]  ? kthread_create_on_node+0x40/0x40
      [ 6250.746768]  ret_from_fork+0x2e/0x40
      [ 6250.746778] ---[ end trace 102a62fd2160f5e6 ]---
      
      v2:
      - Use the new pci_dev->needs_resume flag, to avoid any overhead during
        the ->pm_prepare hook. (Rafael)
      
      v3:
      - Update commit message to reference the actual regressing commit.
        (Lukas)
      
      v4:
      - Rebase on v4 of patch 1/2.
      
      Fixes: d14d2a84 ("drm: Remove dev_pm_ops from drm_class")
      References: https://bugs.freedesktop.org/show_bug.cgi?id=100378
      References: https://bugs.freedesktop.org/show_bug.cgi?id=100770
      Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
      Cc: Marta Lofstedt <marta.lofstedt@intel.com>
      Cc: David Weinehall <david.weinehall@linux.intel.com>
      Cc: Tomi Sarvela <tomi.p.sarvela@intel.com>
      Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
      Cc: Mika Kuoppala <mika.kuoppala@intel.com>
      Cc: Chris Wilson <chris@chris-wilson.co.uk>
      Cc: Takashi Iwai <tiwai@suse.de>
      Cc: Bjorn Helgaas <bhelgaas@google.com>
      Cc: Lukas Wunner <lukas@wunner.de>
      Cc: linux-pci@vger.kernel.org
      Cc: <stable@vger.kernel.org> # v4.10.x: 4d071c32 - PCI/PM: Add needs_resume flag
      Cc: <stable@vger.kernel.org> # v4.10.x
      Signed-off-by: default avatarImre Deak <imre.deak@intel.com>
      Reviewed-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
      Reported-and-tested-by: default avatarMarta Lofstedt <marta.lofstedt@intel.com>
      Link: http://patchwork.freedesktop.org/patch/msgid/1493726649-32094-2-git-send-email-imre.deak@intel.com
      adfdf85d
    • Michel Thierry's avatar
      drm/i915/guc: Fix doorbell id selection · 7f1ea2ac
      Michel Thierry authored
      We are passing parameters in the wrong order to find next zero bit, and
      when it doesn't find anything it returns size (offset in the code), which
      is always zero.
      
      For reference the function is defined as:
      find_next_bit( *addr, size, offset )
      
      The incorrect parameter order was added by commit abddffdf
      ("drm/i915/guc: Sanitize GuC client initialization"). Luckily, currently
      we only use a single guc client and a single doorbell, which happens to be
      zero; therefore it isn't necessary to backport this fix (which would be for
      v4.12).
      
      Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
      Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
      Cc: Oscar Mateo <oscar.mateo@intel.com>
      Signed-off-by: default avatarMichel Thierry <michel.thierry@intel.com>
      Reviewed-by: default avatarDaniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
      Signed-off-by: default avatarJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
      Link: http://patchwork.freedesktop.org/patch/msgid/20170531000546.30762-1-michel.thierry@intel.com
      7f1ea2ac
  3. 30 May, 2017 22 commits
  4. 29 May, 2017 2 commits
  5. 28 May, 2017 2 commits
    • Linus Torvalds's avatar
      Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/evalenti/linux-soc-thermal · d09bc680
      Linus Torvalds authored
      Pull thermal SoC management fixes from Eduardo Valentin:
      
       - fixes to TI SoC driver, Broadcom, qoriq
      
       - small sparse warning fix on thermal core
      
      * 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/evalenti/linux-soc-thermal:
        thermal: broadcom: ns-thermal: default on iProc SoCs
        ti-soc-thermal: Fix a typo in a comment line
        ti-soc-thermal: Delete error messages for failed memory allocations in ti_bandgap_build()
        ti-soc-thermal: Use devm_kcalloc() in ti_bandgap_build()
        thermal: core: make thermal_emergency_poweroff static
        thermal: qoriq: remove useless call for of_thermal_get_trip_points()
      d09bc680
    • Dave Airlie's avatar
      Merge tag 'drm-misc-next-2017-05-26' of git://anongit.freedesktop.org/git/drm-misc into drm-next · 1afc4544
      Dave Airlie authored
      UAPI Changes:
      - Add DRM_MODE_ROTATE_ and DRM_MODE_REFLECT_ defines to the UAPI (Robert)
      
      Cross-subsystem Changes:
      - Standardize sync_file.txt documentation format (Mauro)
      
      Core Changes:
      - Turf drm_[cm]alloc functions for kvmalloc alternatives (Michal)
      - Add optional mode_valid() hook to crtc/encoder/bridge (Jose)
      - Improve documentation around mode validation/alteration (Daniel)
      - Reduce sync_file construction time by deferring name creation (Chris)
      
      Driver Changes:
      - pl111: Wire up the clock divider and add debugfs (Eric)
      - various: Fix include notation and remove -Iinclude/drm (Masahiro)
      - stm: Add Benjamin Gaignard and Vincent Abriou as STM maintainers (Vincent)
      - various: Miscellaneous trivial fixes to pl111/stm/vgem/vc4
      
      Cc: Michal Hocko <mhocko@suse.com>
      Cc: Eric Anholt <eric@anholt.net>
      Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
      Cc: Robert Foss <robert.foss@collabora.com>
      Cc: Vincent Abriou <vincent.abriou@st.com>
      Cc: Jose Abreu <Jose.Abreu@synopsys.com>
      Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
      Cc: Chris Wilson <chris@chris-wilson.co.uk>
      Cc: Mauro Carvalho Chehab <mchehab@s-opensource.com>
      
      * tag 'drm-misc-next-2017-05-26' of git://anongit.freedesktop.org/git/drm-misc: (55 commits)
        dma-buf/sync-file: Defer creation of sync_file->name
        sync_file.txt: standardize document format
        gpu: drm: gma500: remove two more dead variable
        drm/doc: Clarify mode_fixup vs. atomic_check a bit more
        drm/doc: Document adjusted/request modes a bit better
        drm: Add crtc/encoder/bridge->mode_valid() callbacks
        MAINTAINERS: update drm/stm maintainers list
        drm/stm: ltdc: fix duplicated arguments
        drm/pl111: Fix return value check in pl111_amba_probe()
        drm/amd: include <linux/delay.h> instead of "linux/delay.h"
        drm: Add DRM_MODE_ROTATE_ and DRM_MODE_REFLECT_ to UAPI
        drm/vgem: Fix return value check in vgem_init()
        drm/blend: Fix comment typ-o
        drm/stm: remove unneeded -Iinclude/drm compiler flag
        drm/vc4: fix include notation and remove -Iinclude/drm flag
        drm/pl111: Add a debugfs node to dump our registers.
        drm/pl111: make structure mode_config_funcs static
        drm/pl111: make structure pl111_display_funcs static
        drm/pl111: Register the clock divider and use it.
        drm: drop drm_[cm]alloc* helpers
        ...
      1afc4544
  6. 27 May, 2017 11 commits
    • Linus Torvalds's avatar
      Merge tag 'tty-4.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty · 249f1efd
      Linus Torvalds authored
      Pull tty/serial fixes from Greg KH:
       "Here are some serial and tty fixes for 4.12-rc3. They are a bit bigger
        than normal, which is why I had them bake in linux-next for a few
        weeks and didn't send them to you for -rc2.
      
        They revert a few of the serdev patches from 4.12-rc1, and bring
        things back to how they were in 4.11, to try to make things a bit more
        stable there. Rob and Johan both agree that this is the way forward,
        so this isn't people squabbling over semantics. Other than that, just
        a few minor serial driver fixes that people have had problems with.
      
        All of these have been in linux-next for a few weeks with no reported
        issues"
      
      * tag 'tty-4.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
        serial: altera_uart: call iounmap() at driver remove
        serial: imx: ensure UCR3 and UFCR are setup correctly
        MAINTAINERS/serial: Change maintainer of jsm driver
        serial: enable serdev support
        tty/serdev: add serdev registration interface
        serdev: Restore serdev_device_write_buf for atomic context
        serial: core: fix crash in uart_suspend_port
        tty: fix port buffer locking
        tty: ehv_bytechan: clean up init error handling
        serial: ifx6x60: fix use-after-free on module unload
        serial: altera_jtaguart: adding iounmap()
        serial: exar: Fix stuck MSIs
        serial: efm32: Fix parity management in 'efm32_uart_console_get_options()'
        serdev: fix tty-port client deregistration
        Revert "tty_port: register tty ports with serdev bus"
        drivers/tty: 8250: only call fintek_8250_probe when doing port I/O
      249f1efd
    • Linus Torvalds's avatar
      Merge tag 'powerpc-4.12-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux · 6f68a6ae
      Linus Torvalds authored
      Pull powerpc fixes from Michael Ellerman:
       "Fix running SPU programs on Cell, and a few other minor fixes.
      
        Thanks to Alistair Popple, Jeremy Kerr, Michael Neuling, Nicholas
        Piggin"
      
      * tag 'powerpc-4.12-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
        powerpc: Add PPC_FEATURE userspace bits for SCV and DARN instructions
        powerpc/spufs: Fix hash faults for kernel regions
        powerpc: Fix booting P9 hash with CONFIG_PPC_RADIX_MMU=N
        powerpc/powernv/npu-dma.c: Fix opal_npu_destroy_context() call
        selftests/powerpc: Fix TM resched DSCR test with some compilers
      6f68a6ae
    • Linus Torvalds's avatar
      Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · 38e6bf23
      Linus Torvalds authored
      Pull x86 fixes from Thomas Gleixner:
       "A series of fixes for X86:
      
         - The final fix for the end-of-stack issue in the unwinder
         - Handle non PAT systems gracefully
         - Prevent access to uninitiliazed memory
         - Move early delay calaibration after basic init
         - Fix Kconfig help text
         - Fix a cross compile issue
         - Unbreak older make versions"
      
      * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
        x86/timers: Move simple_udelay_calibration past init_hypervisor_platform
        x86/alternatives: Prevent uninitialized stack byte read in apply_alternatives()
        x86/PAT: Fix Xorg regression on CPUs that don't support PAT
        x86/watchdog: Fix Kconfig help text file path reference to lockup watchdog documentation
        x86/build: Permit building with old make versions
        x86/unwind: Add end-of-stack check for ftrace handlers
        Revert "x86/entry: Fix the end of the stack for newly forked tasks"
        x86/boot: Use CROSS_COMPILE prefix for readelf
      38e6bf23
    • Linus Torvalds's avatar
      Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · 39b8ab31
      Linus Torvalds authored
      Pull timer fixlet from Thomas Gleixner:
       "Silence dmesg spam by making the posix cpu timer printks depend on
        print_fatal_signals"
      
      * 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
        posix-timers: Make signal printks conditional
      39b8ab31
    • Linus Torvalds's avatar
      Merge branch 'ras-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · de0b9d75
      Linus Torvalds authored
      Pull RAS fixes from Thomas Gleixner:
       "Two fixlets for RAS:
      
         - Export memory_error() so the NFIT module can utilize it
      
         - Handle memory errors in NFIT correctly"
      
      * 'ras-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
        acpi, nfit: Fix the memory error check in nfit_handle_mce()
        x86/MCE: Export memory_error()
      de0b9d75
    • Linus Torvalds's avatar
      Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · fac3fcae
      Linus Torvalds authored
      Pull perf tooling fixes from Thomas Gleixner:
      
       - Synchronization of tools and kernel headers
      
       - A series of fixes for perf report addressing various failures:
          * Handle invalid maps proper
          * Plug a memory leak
          * Handle frames and callchain order correctly
      
       - Fixes for handling inlines and children mode
      
      * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
        tools/include: Sync kernel ABI headers with tooling headers
        perf tools: Put caller above callee in --children mode
        perf report: Do not drop last inlined frame
        perf report: Always honor callchain order for inlined nodes
        perf script: Add --inline option for debugging
        perf report: Fix off-by-one for non-activation frames
        perf report: Fix memory leak in addr2line when called by addr2inlines
        perf report: Don't crash on invalid maps in `-g srcline` mode
      fac3fcae
    • Linus Torvalds's avatar
      Merge branch 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · 805f2869
      Linus Torvalds authored
      Pull locking fix from Thomas Gleixner:
       "A fix for a state leak which was introduced in the recent rework of
        futex/rtmutex interaction"
      
      * 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
        futex,rt_mutex: Fix rt_mutex_cleanup_proxy_lock()
      805f2869
    • Linus Torvalds's avatar
      Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · d024baa5
      Linus Torvalds authored
      Pull kthread fix from Thomas Gleixner:
       "A single fix which prevents a use after free when kthread fork fails"
      
      * 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
        kthread: Fix use-after-free if kthread fork fails
      d024baa5
    • Linus Torvalds's avatar
      Merge tag 'trace-v4.12-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace · 77d64656
      Linus Torvalds authored
      Pull ftrace fixes from Steven Rostedt:
       "There's been a few memory issues found with ftrace.
      
        One was simply a memory leak where not all was being freed that should
        have been in releasing a file pointer on set_graph_function.
      
        Then Thomas found that the ftrace trampolines were marked for
        read/write as well as execute. To shrink the possible attack surface,
        he added calls to set them to ro. Which also uncovered some other
        issues with freeing module allocated memory that had its permissions
        changed.
      
        Kprobes had a similar issue which is fixed and a selftest was added to
        trigger that issue again"
      
      * tag 'trace-v4.12-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
        x86/ftrace: Make sure that ftrace trampolines are not RWX
        x86/mm/ftrace: Do not bug in early boot on irqs_disabled in cpu_flush_range()
        selftests/ftrace: Add a testcase for many kprobe events
        kprobes/x86: Fix to set RWX bits correctly before releasing trampoline
        ftrace: Fix memory leak in ftrace_graph_release()
      77d64656
    • Thomas Gleixner's avatar
      x86/ftrace: Make sure that ftrace trampolines are not RWX · 6ee98ffe
      Thomas Gleixner authored
      ftrace use module_alloc() to allocate trampoline pages. The mapping of
      module_alloc() is RWX, which makes sense as the memory is written to right
      after allocation. But nothing makes these pages RO after writing to them.
      
      Add proper set_memory_rw/ro() calls to protect the trampolines after
      modification.
      
      Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1705251056410.1862@nanosSigned-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Signed-off-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
      6ee98ffe
    • Steven Rostedt (VMware)'s avatar
      x86/mm/ftrace: Do not bug in early boot on irqs_disabled in cpu_flush_range() · a53276e2
      Steven Rostedt (VMware) authored
      With function tracing starting in early bootup and having its trampoline
      pages being read only, a bug triggered with the following:
      
      kernel BUG at arch/x86/mm/pageattr.c:189!
      invalid opcode: 0000 [#1] SMP
      Modules linked in:
      CPU: 0 PID: 0 Comm: swapper Not tainted 4.12.0-rc2-test+ #3
      Hardware name: MSI MS-7823/CSM-H87M-G43 (MS-7823), BIOS V1.6 02/22/2014
      task: ffffffffb4222500 task.stack: ffffffffb4200000
      RIP: 0010:change_page_attr_set_clr+0x269/0x302
      RSP: 0000:ffffffffb4203c88 EFLAGS: 00010046
      RAX: 0000000000000046 RBX: 0000000000000000 RCX: 00000001b6000000
      RDX: ffffffffb4203d40 RSI: 0000000000000000 RDI: ffffffffb4240d60
      RBP: ffffffffb4203d18 R08: 00000001b6000000 R09: 0000000000000001
      R10: ffffffffb4203aa8 R11: 0000000000000003 R12: ffffffffc029b000
      R13: ffffffffb4203d40 R14: 0000000000000001 R15: 0000000000000000
      FS:  0000000000000000(0000) GS:ffff9a639ea00000(0000) knlGS:0000000000000000
      CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
      CR2: ffff9a636b384000 CR3: 00000001ea21d000 CR4: 00000000000406b0
      Call Trace:
       change_page_attr_clear+0x1f/0x21
       set_memory_ro+0x1e/0x20
       arch_ftrace_update_trampoline+0x207/0x21c
       ? ftrace_caller+0x64/0x64
       ? 0xffffffffc029b000
       ftrace_startup+0xf4/0x198
       register_ftrace_function+0x26/0x3c
       function_trace_init+0x5e/0x73
       tracer_init+0x1e/0x23
       tracing_set_tracer+0x127/0x15a
       register_tracer+0x19b/0x1bc
       init_function_trace+0x90/0x92
       early_trace_init+0x236/0x2b3
       start_kernel+0x200/0x3f5
       x86_64_start_reservations+0x29/0x2b
       x86_64_start_kernel+0x17c/0x18f
       secondary_startup_64+0x9f/0x9f
       ? secondary_startup_64+0x9f/0x9f
      
      Interrupts should not be enabled at this early in the boot process. It is
      also fine to leave interrupts enabled during this time as there's only one
      CPU running, and on_each_cpu() means to only run on the current CPU.
      
      If early_boot_irqs_disabled is set, it is safe to run cpu_flush_range() with
      interrupts disabled. Don't trigger a BUG_ON() in that case.
      
      Link: http://lkml.kernel.org/r/20170526093717.0be3b849@gandalf.local.homeSuggested-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Signed-off-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
      a53276e2