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The vector management code assumes that managed interrupts cannot be
migrated away from an online CPU. free_moved_vector() has a WARN_ON_ONCE()
which triggers when a managed interrupt vector association on a online CPU
is cleared. The CPU offline code uses a different mechanism which cannot
trigger this.
This assumption is not longer correct because the new CPU isolation feature
which affects the placement of managed interrupts must be able to move a
managed interrupt away from an online CPU.
There are two reasons why this can happen:
1) When the interrupt is activated the affinity mask which was
established in irq_create_affinity_masks() is handed in to
the vector allocation code. This mask contains all CPUs to which
the interrupt can be made affine to, but this does not take the
CPU isolation 'managed_irq' mask into account.
When the interrupt is finally requested by the device driver then the
affinity is checked again and the CPU isolation 'managed_irq' mask is
taken into account, which moves the interrupt to a non-isolated CPU if
possible.
2) The interrupt can be affine to an isolated CPU because the
non-isolated CPUs in the calculated affinity mask are not online.
Once a non-isolated CPU which is in the mask comes online the
interrupt is migrated to this non-isolated CPU
In both cases the regular online migration mechanism is used which triggers
the WARN_ON_ONCE() in free_moved_vector().
Case #1 could have been addressed by taking the isolation mask into
account, but that would require a massive code change in the activation
logic and the eventual migration event was accepted as a reasonable
tradeoff when the isolation feature was developed. But even if #1 would be
addressed, #2 would still trigger it.
Of course the warning in free_moved_vector() was overlooked at that time
and the above two cases which have been discussed during patch review have
obviously never been tested before the final submission.
So keep it simple and remove the warning.
[ tglx: Rewrote changelog and added a comment to free_moved_vector() ]
Fixes: 11ea68f553e2 ("genirq, sched/isolation: Isolate from handling managed interrupts")
Signed-off-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Link: https://lkml.kernel.org/r/20200312205830.81796-1-peterx@redhat.com
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Thomas Gleixner:
"A set of fixes for X86:
- Ensure that the PIT is set up when the local APIC is disable or
configured in legacy mode. This is caused by an ordering issue
introduced in the recent changes which skip PIT initialization when
the TSC and APIC frequencies are already known.
- Handle malformed SRAT tables during early ACPI parsing which caused
an infinite loop anda boot hang.
- Fix a long standing race in the affinity setting code which affects
PCI devices with non-maskable MSI interrupts. The problem is caused
by the non-atomic writes of the MSI address (destination APIC id)
and data (vector) fields which the device uses to construct the MSI
message. The non-atomic writes are mandated by PCI.
If both fields change and the device raises an interrupt after
writing address and before writing data, then the MSI block
constructs a inconsistent message which causes interrupts to be
lost and subsequent malfunction of the device.
The fix is to redirect the interrupt to the new vector on the
current CPU first and then switch it over to the new target CPU.
This allows to observe an eventually raised interrupt in the
transitional stage (old CPU, new vector) to be observed in the APIC
IRR and retriggered on the new target CPU and the new vector.
The potential spurious interrupts caused by this are harmless and
can in the worst case expose a buggy driver (all handlers have to
be able to deal with spurious interrupts as they can and do happen
for various reasons).
- Add the missing suspend/resume mechanism for the HYPERV hypercall
page which prevents resume hibernation on HYPERV guests. This
change got lost before the merge window.
- Mask the IOAPIC before disabling the local APIC to prevent
potentially stale IOAPIC remote IRR bits which cause stale
interrupt lines after resume"
* tag 'x86-urgent-2020-02-09' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/apic: Mask IOAPIC entries when disabling the local APIC
x86/hyperv: Suspend/resume the hypercall page for hibernation
x86/apic/msi: Plug non-maskable MSI affinity race
x86/boot: Handle malformed SRAT tables during early ACPI parsing
x86/timer: Don't skip PIT setup when APIC is disabled or in legacy mode
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When a system suspends, the local APIC is disabled in the suspend sequence,
but the IOAPIC is left in the current state. This means unmasked interrupt
lines stay unmasked. This is usually the case for IOAPIC pin 9 to which the
ACPI interrupt is connected.
That means that in suspended state the IOAPIC can respond to an external
interrupt, e.g. the wakeup via keyboard/RTC/ACPI, but the interrupt message
cannot be handled by the disabled local APIC. As a consequence the Remote
IRR bit is set, but the local APIC does not send an EOI to acknowledge
it. This causes the affected interrupt line to become stale and the stale
Remote IRR bit will cause a hang when __synchronize_hardirq() is invoked
for that interrupt line.
To prevent this, mask all IOAPIC entries before disabling the local
APIC. The resume code already has the unmask operation inside.
[ tglx: Massaged changelog ]
Signed-off-by: Tony W Wang-oc <TonyWWang-oc@zhaoxin.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/1579076539-7267-1-git-send-email-TonyWWang-oc@zhaoxin.com
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Evan tracked down a subtle race between the update of the MSI message and
the device raising an interrupt internally on PCI devices which do not
support MSI masking. The update of the MSI message is non-atomic and
consists of either 2 or 3 sequential 32bit wide writes to the PCI config
space.
- Write address low 32bits
- Write address high 32bits (If supported by device)
- Write data
When an interrupt is migrated then both address and data might change, so
the kernel attempts to mask the MSI interrupt first. But for MSI masking is
optional, so there exist devices which do not provide it. That means that
if the device raises an interrupt internally between the writes then a MSI
message is sent built from half updated state.
On x86 this can lead to spurious interrupts on the wrong interrupt
vector when the affinity setting changes both address and data. As a
consequence the device interrupt can be lost causing the device to
become stuck or malfunctioning.
Evan tried to handle that by disabling MSI accross an MSI message
update. That's not feasible because disabling MSI has issues on its own:
If MSI is disabled the PCI device is routing an interrupt to the legacy
INTx mechanism. The INTx delivery can be disabled, but the disablement is
not working on all devices.
Some devices lose interrupts when both MSI and INTx delivery are disabled.
Another way to solve this would be to enforce the allocation of the same
vector on all CPUs in the system for this kind of screwed devices. That
could be done, but it would bring back the vector space exhaustion problems
which got solved a few years ago.
Fortunately the high address (if supported by the device) is only relevant
when X2APIC is enabled which implies interrupt remapping. In the interrupt
remapping case the affinity setting is happening at the interrupt remapping
unit and the PCI MSI message is programmed only once when the PCI device is
initialized.
That makes it possible to solve it with a two step update:
1) Target the MSI msg to the new vector on the current target CPU
2) Target the MSI msg to the new vector on the new target CPU
In both cases writing the MSI message is only changing a single 32bit word
which prevents the issue of inconsistency.
After writing the final destination it is necessary to check whether the
device issued an interrupt while the intermediate state #1 (new vector,
current CPU) was in effect.
This is possible because the affinity change is always happening on the
current target CPU. The code runs with interrupts disabled, so the
interrupt can be detected by checking the IRR of the local APIC. If the
vector is pending in the IRR then the interrupt is retriggered on the new
target CPU by sending an IPI for the associated vector on the target CPU.
This can cause spurious interrupts on both the local and the new target
CPU.
1) If the new vector is not in use on the local CPU and the device
affected by the affinity change raised an interrupt during the
transitional state (step #1 above) then interrupt entry code will
ignore that spurious interrupt. The vector is marked so that the
'No irq handler for vector' warning is supressed once.
2) If the new vector is in use already on the local CPU then the IRR check
might see an pending interrupt from the device which is using this
vector. The IPI to the new target CPU will then invoke the handler of
the device, which got the affinity change, even if that device did not
issue an interrupt
3) If the new vector is in use already on the local CPU and the device
affected by the affinity change raised an interrupt during the
transitional state (step #1 above) then the handler of the device which
uses that vector on the local CPU will be invoked.
expose issues in device driver interrupt handlers which are not prepared to
handle a spurious interrupt correctly. This not a regression, it's just
exposing something which was already broken as spurious interrupts can
happen for a lot of reasons and all driver handlers need to be able to deal
with them.
Reported-by: Evan Green <evgreen@chromium.org>
Debugged-by: Evan Green <evgreen@chromium.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Evan Green <evgreen@chromium.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/87imkr4s7n.fsf@nanos.tec.linutronix.de
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Tony reported a boot regression caused by the recent workaround for systems
which have a disabled (clock gate off) PIT.
On his machine the kernel fails to initialize the PIT because
apic_needs_pit() does not take into account whether the local APIC
interrupt delivery mode will actually allow to setup and use the local
APIC timer. This should be easy to reproduce with acpi=off on the
command line which also disables HPET.
Due to the way the PIT/HPET and APIC setup ordering works (APIC setup can
require working PIT/HPET) the information is not available at the point
where apic_needs_pit() makes this decision.
To address this, split out the interrupt mode selection from
apic_intr_mode_init(), invoke the selection before making the decision
whether PIT is required or not, and add the missing checks into
apic_needs_pit().
Fixes: c8c4076723da ("x86/timer: Skip PIT initialization on modern chipsets")
Reported-by: Anthony Buckley <tony.buckley000@gmail.com>
Tested-by: Anthony Buckley <tony.buckley000@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Daniel Drake <drake@endlessm.com>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=206125
Link: https://lore.kernel.org/r/87sgk6tmk2.fsf@nanos.tec.linutronix.de
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When CONFIG_PROC_FS is disabled, the compiler warns about an unused
variable:
arch/x86/kernel/apic/x2apic_uv_x.c: In function 'uv_setup_proc_files':
arch/x86/kernel/apic/x2apic_uv_x.c:1546:8: error: unused variable 'name' [-Werror=unused-variable]
char *name = hubless ? "hubless" : "hubbed";
Simplify the code so this variable is no longer needed.
Fixes: 8785968bce1c ("x86/platform/uv: Add UV Hubbed/Hubless Proc FS Files")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20191212140419.315264-1-arnd@arndb.de
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 platform updates from Ingo Molnar:
"UV platform updates (with a 'hubless' variant) and Jailhouse updates
for better UART support"
* 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/jailhouse: Only enable platform UARTs if available
x86/jailhouse: Improve setup data version comparison
x86/platform/uv: Account for UV Hubless in is_uvX_hub Ops
x86/platform/uv: Check EFI Boot to set reboot type
x86/platform/uv: Decode UVsystab Info
x86/platform/uv: Add UV Hubbed/Hubless Proc FS Files
x86/platform/uv: Setup UV functions for Hubless UV Systems
x86/platform/uv: Add return code to UV BIOS Init function
x86/platform/uv: Return UV Hubless System Type
x86/platform/uv: Save OEM_ID from ACPI MADT probe
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'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 objtool, cleanup, and apic updates from Ingo Molnar:
"Objtool:
- Fix a gawk 5.0 incompatibility in gen-insn-attr-x86.awk. Most
distros are still on gawk 4.2.x.
Cleanup:
- Misc cleanups, plus the removal of obsolete code such as Calgary
IOMMU support, which code hasn't seen any real testing in a long
time and there's no known users left.
apic:
- Two changes: a cleanup and a fix for an (old) race for oneshot
threaded IRQ handlers"
* 'core-objtool-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/insn: Fix awk regexp warnings
* 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86: Remove unused asm/rio.h
x86: Fix typos in comments
x86/pci: Remove #ifdef __KERNEL__ guard from <asm/pci.h>
x86/pci: Remove pci_64.h
x86: Remove the calgary IOMMU driver
x86/apic, x86/uprobes: Correct parameter names in kernel-doc comments
x86/kdump: Remove the unused crash_copy_backup_region()
x86/nmi: Remove stale EDAC include leftover
* 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/ioapic: Rename misnamed functions
x86/ioapic: Prevent inconsistent state when moving an interrupt
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git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk
Pull printk updates from Petr Mladek:
- Allow to print symbolic error names via new %pe modifier.
- Use pr_warn() instead of the remaining pr_warning() calls. Fix
formatting of the related lines.
- Add VSPRINTF entry to MAINTAINERS.
* tag 'printk-for-5.5' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk: (32 commits)
checkpatch: don't warn about new vsprintf pointer extension '%pe'
MAINTAINERS: Add VSPRINTF
tools lib api: Renaming pr_warning to pr_warn
ASoC: samsung: Use pr_warn instead of pr_warning
lib: cpu_rmap: Use pr_warn instead of pr_warning
trace: Use pr_warn instead of pr_warning
dma-debug: Use pr_warn instead of pr_warning
vgacon: Use pr_warn instead of pr_warning
fs: afs: Use pr_warn instead of pr_warning
sh/intc: Use pr_warn instead of pr_warning
scsi: Use pr_warn instead of pr_warning
platform/x86: intel_oaktrail: Use pr_warn instead of pr_warning
platform/x86: asus-laptop: Use pr_warn instead of pr_warning
platform/x86: eeepc-laptop: Use pr_warn instead of pr_warning
oprofile: Use pr_warn instead of pr_warning
of: Use pr_warn instead of pr_warning
macintosh: Use pr_warn instead of pr_warning
idsn: Use pr_warn instead of pr_warning
ide: Use pr_warn instead of pr_warning
crypto: n2: Use pr_warn instead of pr_warning
...
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The removal of the LDR initialization in the bigsmp_32 APIC code unearthed
a problem in setup_local_APIC().
The code checks unconditionally for a mismatch of the logical APIC id by
comparing the early APIC id which was initialized in get_smp_config() with
the actual LDR value in the APIC.
Due to the removal of the bogus LDR initialization the check now can
trigger on bigsmp_32 APIC systems emitting a warning for every booting
CPU. This is of course a false positive because the APIC is not using
logical destination mode.
Restrict the check and the possibly resulting fixup to systems which are
actually using the APIC in logical destination mode.
[ tglx: Massaged changelog and added Cc stable ]
Fixes: bae3a8d3308 ("x86/apic: Do not initialize LDR and DFR for bigsmp")
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/666d8f91-b5a8-1afd-7add-821e72a35f03@suse.com
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Rename parameter names to the correct ones used in the function. No
functional changes.
[ bp: Merge two patches into a single one. ]
Signed-off-by: Yi Wang <wang.yi59@zte.com.cn>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/1571816442-22494-1-git-send-email-wang.yi59@zte.com.cn
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ioapic_irqd_[un]mask() are misnomers as both functions do way more than
masking and unmasking the interrupt line. Both deal with the moving the
affinity of the interrupt within interrupt context. The mask/unmask is just
a tiny part of the functionality.
Rename them to ioapic_prepare/finish_move(), fixup the call sites and
rename the related variables in the code to reflect what this is about.
No functional change.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Link: https://lkml.kernel.org/r/20191017101938.412489856@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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There is an issue with threaded interrupts which are marked ONESHOT
and using the fasteoi handler:
if (IS_ONESHOT())
mask_irq();
....
cond_unmask_eoi_irq()
chip->irq_eoi();
if (setaffinity_pending) {
mask_ioapic();
...
move_affinity();
unmask_ioapic();
}
So if setaffinity is pending the interrupt will be moved and then
unconditionally unmasked at the ioapic level, which is wrong in two
aspects:
1) It should be kept masked up to the point where the threaded handler
finished.
2) The physical chip state and the software masked state are inconsistent
Guard both the mask and the unmask with a check for the software masked
state. If the line is marked masked then the ioapic line is also masked, so
both mask_ioapic() and unmask_ioapic() can be skipped safely.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Fixes: 3aa551c9b4c4 ("genirq: add threaded interrupt handler support")
Link: https://lkml.kernel.org/r/20191017101938.321393687@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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As said in commit f2c2cbcc35d4 ("powerpc: Use pr_warn instead of
pr_warning"), removing pr_warning so all logging messages use a
consistent <prefix>_warn style. Let's do it.
Link: http://lkml.kernel.org/r/20191018031850.48498-7-wangkefeng.wang@huawei.com
To: linux-kernel@vger.kernel.org
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Robert Richter <rric@kernel.org>
Cc: Darren Hart <dvhart@infradead.org>
Cc: Andy Shevchenko <andy@infradead.org>
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
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Check that the per-cpu cluster mask pointer has been set prior to
clearing a dying cpu's bit. The per-cpu pointer is not set until the
target cpu reaches smp_callin() during CPUHP_BRINGUP_CPU, whereas the
teardown function, x2apic_dead_cpu(), is associated with the earlier
CPUHP_X2APIC_PREPARE. If an error occurs before the cpu is awakened,
e.g. if do_boot_cpu() itself fails, x2apic_dead_cpu() will dereference
the NULL pointer and cause a panic.
smpboot: do_boot_cpu failed(-22) to wakeup CPU#1
BUG: kernel NULL pointer dereference, address: 0000000000000008
RIP: 0010:x2apic_dead_cpu+0x1a/0x30
Call Trace:
cpuhp_invoke_callback+0x9a/0x580
_cpu_up+0x10d/0x140
do_cpu_up+0x69/0xb0
smp_init+0x63/0xa9
kernel_init_freeable+0xd7/0x229
? rest_init+0xa0/0xa0
kernel_init+0xa/0x100
ret_from_fork+0x35/0x40
Fixes: 023a611748fd5 ("x86/apic/x2apic: Simplify cluster management")
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20191001205019.5789-1-sean.j.christopherson@intel.com
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Change to checking for EFI Boot type from previous check on if this
is a KDUMP kernel. This allows for KDUMP kernels that can handle
EFI reboots.
Signed-off-by: Mike Travis <mike.travis@hpe.com>
Reviewed-by: Steve Wahl <steve.wahl@hpe.com>
Reviewed-by: Dimitri Sivanich <dimitri.sivanich@hpe.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Hedi Berriche <hedi.berriche@hpe.com>
Cc: Justin Ernst <justin.ernst@hpe.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russ Anderson <russ.anderson@hpe.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190910145840.215091717@stormcage.eag.rdlabs.hpecorp.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Decode the hubless UVsystab passed from BIOS to the kernel saving
pertinent info in a similar manner that hubbed UVsystabs are decoded.
Signed-off-by: Mike Travis <mike.travis@hpe.com>
Reviewed-by: Steve Wahl <steve.wahl@hpe.com>
Reviewed-by: Dimitri Sivanich <dimitri.sivanich@hpe.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Hedi Berriche <hedi.berriche@hpe.com>
Cc: Justin Ernst <justin.ernst@hpe.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russ Anderson <russ.anderson@hpe.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190910145840.135325066@stormcage.eag.rdlabs.hpecorp.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Indicate to UV user utilities that UV hubless support is available on
this system via the existing /proc infterface. The current interface is
maintained with the addition of new /proc leaves ("hubbed", "hubless",
and "oemid") that contain the specific type of UV arch this one is.
Signed-off-by: Mike Travis <mike.travis@hpe.com>
Reviewed-by: Steve Wahl <steve.wahl@hpe.com>
Reviewed-by: Dimitri Sivanich <dimitri.sivanich@hpe.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Hedi Berriche <hedi.berriche@hpe.com>
Cc: Justin Ernst <justin.ernst@hpe.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russ Anderson <russ.anderson@hpe.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190910145840.055590900@stormcage.eag.rdlabs.hpecorp.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Add more support for UV systems that do not contain a UV Hub (AKA
"hubless"). This update adds support for additional functions required:
Use PCH NMI handler instead of a UV Hub NMI handler.
Initialize the UV BIOS callback interface used to support specific
UV functions.
Signed-off-by: Mike Travis <mike.travis@hpe.com>
Reviewed-by: Steve Wahl <steve.wahl@hpe.com>
Reviewed-by: Dimitri Sivanich <dimitri.sivanich@hpe.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Hedi Berriche <hedi.berriche@hpe.com>
Cc: Justin Ernst <justin.ernst@hpe.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russ Anderson <russ.anderson@hpe.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190910145839.975787119@stormcage.eag.rdlabs.hpecorp.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Return the type of UV hubless system for UV specific code that depends
on that. Add a function to convert UV system type to bit pattern needed
for is_uv_hubless().
Signed-off-by: Mike Travis <mike.travis@hpe.com>
Reviewed-by: Steve Wahl <steve.wahl@hpe.com>
Reviewed-by: Dimitri Sivanich <dimitri.sivanich@hpe.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Hedi Berriche <hedi.berriche@hpe.com>
Cc: Justin Ernst <justin.ernst@hpe.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russ Anderson <russ.anderson@hpe.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190910145839.814880843@stormcage.eag.rdlabs.hpecorp.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Save the OEM_ID and OEM_TABLE_ID passed to the apic driver probe function
for later use. Also, convert the char list arg passed from the kernel
to a true null-terminated string.
Signed-off-by: Mike Travis <mike.travis@hpe.com>
Reviewed-by: Steve Wahl <steve.wahl@hpe.com>
Reviewed-by: Dimitri Sivanich <dimitri.sivanich@hpe.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Hedi Berriche <hedi.berriche@hpe.com>
Cc: Justin Ernst <justin.ernst@hpe.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russ Anderson <russ.anderson@hpe.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190910145839.732237241@stormcage.eag.rdlabs.hpecorp.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 apic updates from Thomas Gleixner:
- Cleanup the apic IPI implementation by removing duplicated code and
consolidating the functions into the APIC core.
- Implement a safe variant of the IPI broadcast mode. Contrary to
earlier attempts this uses the core tracking of which CPUs have been
brought online at least once so that a broadcast does not end up in
some dead end in BIOS/SMM code when the CPU is still waiting for
init. Once all CPUs have been brought up once, IPI broadcasting is
enabled. Before that regular one by one IPIs are issued.
- Drop the paravirt CR8 related functions as they have no user anymore
- Initialize the APIC TPR to block interrupt 16-31 as they are reserved
for CPU exceptions and should never be raised by any well behaving
device.
- Emit a warning when vector space exhaustion breaks the admin set
affinity of an interrupt.
- Make sure to use the NMI fallback when shutdown via reboot vector IPI
fails. The original code had conditions which prevent the code path
to be reached.
- Annotate various APIC config variables as RO after init.
[ The ipi broadcase change came in earlier through the cpu hotplug
branch, but I left the explanation in the commit message since it was
shared between the two different branches - Linus ]
* 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (28 commits)
x86/apic/vector: Warn when vector space exhaustion breaks affinity
x86/apic: Annotate global config variables as "read-only after init"
x86/apic/x2apic: Implement IPI shorthands support
x86/apic/flat64: Remove the IPI shorthand decision logic
x86/apic: Share common IPI helpers
x86/apic: Remove the shorthand decision logic
x86/smp: Enhance native_send_call_func_ipi()
x86/smp: Move smp_function_call implementations into IPI code
x86/apic: Provide and use helper for send_IPI_allbutself()
x86/apic: Add static key to Control IPI shorthands
x86/apic: Move no_ipi_broadcast() out of 32bit
x86/apic: Add NMI_VECTOR wait to IPI shorthand
x86/apic: Remove dest argument from __default_send_IPI_shortcut()
x86/hotplug: Silence APIC and NMI when CPU is dead
x86/cpu: Move arch_smt_update() to a neutral place
x86/apic/uv: Make x2apic_extra_bits static
x86/apic: Consolidate the apic local headers
x86/apic: Move apic_flat_64 header into apic directory
x86/apic: Move ipi header into apic directory
x86/apic: Cleanup the include maze
...
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 cpu-feature updates from Ingo Molnar:
- Rework the Intel model names symbols/macros, which were decades of
ad-hoc extensions and added random noise. It's now a coherent, easy
to follow nomenclature.
- Add new Intel CPU model IDs:
- "Tiger Lake" desktop and mobile models
- "Elkhart Lake" model ID
- and the "Lightning Mountain" variant of Airmont, plus support code
- Add the new AVX512_VP2INTERSECT instruction to cpufeatures
- Remove Intel MPX user-visible APIs and the self-tests, because the
toolchain (gcc) is not supporting it going forward. This is the
first, lowest-risk phase of MPX removal.
- Remove X86_FEATURE_MFENCE_RDTSC
- Various smaller cleanups and fixes
* 'x86-cpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (25 commits)
x86/cpu: Update init data for new Airmont CPU model
x86/cpu: Add new Airmont variant to Intel family
x86/cpu: Add Elkhart Lake to Intel family
x86/cpu: Add Tiger Lake to Intel family
x86: Correct misc typos
x86/intel: Add common OPTDIFFs
x86/intel: Aggregate microserver naming
x86/intel: Aggregate big core graphics naming
x86/intel: Aggregate big core mobile naming
x86/intel: Aggregate big core client naming
x86/cpufeature: Explain the macro duplication
x86/ftrace: Remove mcount() declaration
x86/PCI: Remove superfluous returns from void functions
x86/msr-index: Move AMD MSRs where they belong
x86/cpu: Use constant definitions for CPU models
lib: Remove redundant ftrace flag removal
x86/crash: Remove unnecessary comparison
x86/bitops: Use __builtin_constant_p() directly instead of IS_IMMEDIATE()
x86: Remove X86_FEATURE_MFENCE_RDTSC
x86/mpx: Remove MPX APIs
...
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Ingo Molnar:
"A KVM guest fix, and a kdump kernel relocation errors fix"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/timer: Force PIT initialization when !X86_FEATURE_ARAT
x86/purgatory: Change compiler flags from -mcmodel=kernel to -mcmodel=large to fix kexec relocation errors
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KVM guests with commit c8c4076723da ("x86/timer: Skip PIT initialization on
modern chipsets") applied to guest kernel have been observed to have
unusually higher CPU usage with symptoms of increase in vm exits for HLT
and MSW_WRITE (MSR_IA32_TSCDEADLINE).
This is caused by older QEMUs lacking support for X86_FEATURE_ARAT. lapic
clock retains CLOCK_EVT_FEAT_C3STOP and nohz stays inactive. There's no
usable broadcast device either.
Do the PIT initialization if guest CPU lacks X86_FEATURE_ARAT. On real
hardware it shouldn't matter as ARAT and DEADLINE come together.
Fixes: c8c4076723da ("x86/timer: Skip PIT initialization on modern chipsets")
Signed-off-by: Jan Stancek <jstancek@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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This reverts commit 558682b5291937a70748d36fd9ba757fb25b99ae.
Chris Wilson reports that it breaks his CPU hotplug test scripts. In
particular, it breaks offlining and then re-onlining the boot CPU, which
we treat specially (and the BIOS does too).
The symptoms are that we can offline the CPU, but it then does not come
back online again:
smpboot: CPU 0 is now offline
smpboot: Booting Node 0 Processor 0 APIC 0x0
smpboot: do_boot_cpu failed(-1) to wakeup CPU#0
Thomas says he knows why it's broken (my personal suspicion: our magic
handling of the "cpu0_logical_apicid" thing), but for 5.3 the right fix
is to just revert it, since we've never touched the LDR bits before, and
it's not worth the risk to do anything else at this stage.
[ Hotpluging of the boot CPU is special anyway, and should be off by
default. See the "BOOTPARAM_HOTPLUG_CPU0" config option and the
cpu0_hotplug kernel parameter.
In general you should not do it, and it has various known limitations
(hibernate and suspend require the boot CPU, for example).
But it should work, even if the boot CPU is special and needs careful
treatment - Linus ]
Link: https://lore.kernel.org/lkml/156785100521.13300.14461504732265570003@skylake-alporthouse-com/
Reported-by: Chris Wilson <chris@chris-wilson.co.uk>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Bandan Das <bsd@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Conflicts:
tools/power/x86/turbostat/turbostat.c
Recent turbostat changes conflicted with a pending rename of x86 model names in tip:x86/cpu,
sort it out.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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On x86, CPUs are limited in the number of interrupts they can have affined
to them as they only support 256 interrupt vectors per CPU. 32 vectors are
reserved for the CPU and the kernel reserves another 22 for internal
purposes. That leaves 202 vectors for assignement to devices.
When an interrupt is set up or the affinity is changed by the kernel or the
administrator, the vector assignment code attempts to honor the requested
affinity mask. If the vector space on the CPUs in that affinity mask is
exhausted the code falls back to a wider set of CPUs and assigns a vector
on a CPU outside of the requested affinity mask silently.
While the effective affinity is reflected in the corresponding
/proc/irq/$N/effective_affinity* files the silent breakage of the requested
affinity can lead to unexpected behaviour for administrators.
Add a pr_warn() when this happens so that adminstrators get at least
informed about it in the syslog.
[ tglx: Massaged changelog and made the pr_warn() more informative ]
Reported-by: djuran@redhat.com
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: djuran@redhat.com
Link: https://lkml.kernel.org/r/20190822143421.9535-1-nhorman@tuxdriver.com
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Currently big microservers have _XEON_D while small microservers have
_X, Make it uniformly: _D.
for i in `git grep -l "\(INTEL_FAM6_\|VULNWL_INTEL\|INTEL_CPU_FAM6\).*_\(X\|XEON_D\)"`
do
sed -i -e 's/\(\(INTEL_FAM6_\|VULNWL_INTEL\|INTEL_CPU_FAM6\).*ATOM.*\)_X/\1_D/g' \
-e 's/\(\(INTEL_FAM6_\|VULNWL_INTEL\|INTEL_CPU_FAM6\).*\)_XEON_D/\1_D/g' ${i}
done
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Cc: x86@kernel.org
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Borislav Petkov <bp@alien8.de>
Link: https://lkml.kernel.org/r/20190827195122.677152989@infradead.org
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Currently big core clients with extra graphics on have:
- _G
- _GT3E
Make it uniformly: _G
for i in `git grep -l "\(INTEL_FAM6_\|VULNWL_INTEL\|INTEL_CPU_FAM6\).*_GT3E"`
do
sed -i -e 's/\(\(INTEL_FAM6_\|VULNWL_INTEL\|INTEL_CPU_FAM6\).*\)_GT3E/\1_G/g' ${i}
done
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Cc: x86@kernel.org
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Borislav Petkov <bp@alien8.de>
Link: https://lkml.kernel.org/r/20190827195122.622802314@infradead.org
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Currently big core mobile chips have either:
- _L
- _ULT
- _MOBILE
Make it uniformly: _L.
for i in `git grep -l "\(INTEL_FAM6_\|VULNWL_INTEL\|INTEL_CPU_FAM6\).*_\(MOBILE\|ULT\)"`
do
sed -i -e 's/\(\(INTEL_FAM6_\|VULNWL_INTEL\|INTEL_CPU_FAM6\).*\)_\(MOBILE\|ULT\)/\1_L/g' ${i}
done
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Cc: x86@kernel.org
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190827195122.568978530@infradead.org
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Currently the big core client models either have:
- no OPTDIFF
- _CORE
- _DESKTOP
Make it uniformly: 'no OPTDIFF'.
for i in `git grep -l "\(INTEL_FAM6_\|VULNWL_INTEL\|INTEL_CPU_FAM6\).*_\(CORE\|DESKTOP\)"`
do
sed -i -e 's/\(\(INTEL_FAM6_\|VULNWL_INTEL\|INTEL_CPU_FAM6\).*\)_\(CORE\|DESKTOP\)/\1/g' ${i}
done
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Cc: x86@kernel.org
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190827195122.513945586@infradead.org
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Although APIC initialization will typically clear out the LDR before
setting it, the APIC cleanup code should reset the LDR.
This was discovered with a 32-bit KVM guest jumping into a kdump
kernel. The stale bits in the LDR triggered a bug in the KVM APIC
implementation which caused the destination mapping for VCPUs to be
corrupted.
Note that this isn't intended to paper over the KVM APIC bug. The kernel
has to clear the LDR when resetting the APIC registers except when X2APIC
is enabled.
This lacks a Fixes tag because missing to clear LDR goes way back into pre
git history.
[ tglx: Made x2apic_enabled a function call as required ]
Signed-off-by: Bandan Das <bsd@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20190826101513.5080-3-bsd@redhat.com
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Legacy apic init uses bigsmp for smp systems with 8 and more CPUs. The
bigsmp APIC implementation uses physical destination mode, but it
nevertheless initializes LDR and DFR. The LDR even ends up incorrectly with
multiple bit being set.
This does not cause a functional problem because LDR and DFR are ignored
when physical destination mode is active, but it triggered a problem on a
32-bit KVM guest which jumps into a kdump kernel.
The multiple bits set unearthed a bug in the KVM APIC implementation. The
code which creates the logical destination map for VCPUs ignores the
disabled state of the APIC and ends up overwriting an existing valid entry
and as a result, APIC calibration hangs in the guest during kdump
initialization.
Remove the bogus LDR/DFR initialization.
This is not intended to work around the KVM APIC bug. The LDR/DFR
ininitalization is wrong on its own.
The issue goes back into the pre git history. The fixes tag is the commit
in the bitkeeper import which introduced bigsmp support in 2003.
git://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git
Fixes: db7b9e9f26b8 ("[PATCH] Clustered APIC setup for >8 CPU systems")
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Bandan Das <bsd@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20190826101513.5080-2-bsd@redhat.com
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Rahul Tanwar reported the following bug on DT systems:
> 'ioapic_dynirq_base' contains the virtual IRQ base number. Presently, it is
> updated to the end of hardware IRQ numbers but this is done only when IOAPIC
> configuration type is IOAPIC_DOMAIN_LEGACY or IOAPIC_DOMAIN_STRICT. There is
> a third type IOAPIC_DOMAIN_DYNAMIC which applies when IOAPIC configuration
> comes from devicetree.
>
> See dtb_add_ioapic() in arch/x86/kernel/devicetree.c
>
> In case of IOAPIC_DOMAIN_DYNAMIC (DT/OF based system), 'ioapic_dynirq_base'
> remains to zero initialized value. This means that for OF based systems,
> virtual IRQ base will get set to zero.
Such systems will very likely not even boot.
For DT enabled machines ioapic_dynirq_base is irrelevant and not
updated, so simply map the IRQ base 1:1 instead.
Reported-by: Rahul Tanwar <rahul.tanwar@linux.intel.com>
Tested-by: Rahul Tanwar <rahul.tanwar@linux.intel.com>
Tested-by: Andy Shevchenko <andriy.shevchenko@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: alan@linux.intel.com
Cc: bp@alien8.de
Cc: cheol.yong.kim@intel.com
Cc: qi-ming.wu@intel.com
Cc: rahul.tanwar@intel.com
Cc: rppt@linux.ibm.com
Cc: tony.luck@intel.com
Link: http://lkml.kernel.org/r/20190821081330.1187-1-rahul.tanwar@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Some newer machines do not advertise legacy timers. The kernel can handle
that situation if the TSC and the CPU frequency are enumerated by CPUID or
MSRs and the CPU supports TSC deadline timer. If the CPU does not support
TSC deadline timer the local APIC timer frequency has to be known as well.
Some Ryzens machines do not advertize legacy timers, but there is no
reliable way to determine the bus frequency which feeds the local APIC
timer when the machine allows overclocking of that frequency.
As there is no legacy timer the local APIC timer calibration crashes due to
a NULL pointer dereference when accessing the not installed global clock
event device.
Switch the calibration loop to a non interrupt based one, which polls
either TSC (if frequency is known) or jiffies. The latter requires a global
clockevent. As the machines which do not have a global clockevent installed
have a known TSC frequency this is a non issue. For older machines where
TSC frequency is not known, there is no known case where the legacy timers
do not exist as that would have been reported long ago.
Reported-by: Daniel Drake <drake@endlessm.com>
Reported-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Daniel Drake <drake@endlessm.com>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/alpine.DEB.2.21.1908091443030.21433@nanos.tec.linutronix.de
Link: http://bugzilla.opensuse.org/show_bug.cgi?id=1142926#c12
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Fix
arch/x86/kernel/apic/probe_32.c: In function ‘default_setup_apic_routing’:
arch/x86/kernel/apic/probe_32.c:146:7: warning: this statement may fall through [-Wimplicit-fallthrough=]
if (!APIC_XAPIC(version)) {
^
arch/x86/kernel/apic/probe_32.c:151:3: note: here
case X86_VENDOR_HYGON:
^~~~
for 32-bit builds.
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190811154036.29805-1-bp@alien8.de
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Mark the APIC's global config variables that are constant after boot as
__ro_after_init to help document that the majority of the APIC config is
not changed at runtime, and to harden the kernel a smidge.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190805212134.12001-1-sean.j.christopherson@intel.com
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All callers of apic->send_IPI_all() and apic->send_IPI_allbutself() contain
the decision logic for shorthand invocation already and invoke
send_IPI_mask() if the prereqisites are not satisfied.
Implement shorthand support for x2apic.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20190722105221.134696837@linutronix.de
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All callers of apic->send_IPI_all() and apic->send_IPI_allbutself() contain
the decision logic for shorthand invocation already and invoke
send_IPI_mask() if the prereqisites are not satisfied.
Remove the now redundant decision logic in the APIC code and the duplicate
helper in probe_64.c.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20190722105221.042964120@linutronix.de
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The 64bit implementations need the same wrappers around
__default_send_IPI_shortcut() as 32bit.
Move them out of the 32bit section.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20190722105220.951534451@linutronix.de
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All callers of apic->send_IPI_all() and apic->send_IPI_allbutself() contain
the decision logic for shorthand invocation already and invoke
send_IPI_mask() if the prereqisites are not satisfied.
Remove the now redundant decision logic in the 32bit implementation.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20190722105220.860244707@linutronix.de
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Nadav noticed that the cpumask allocations in native_send_call_func_ipi()
are noticeable in microbenchmarks.
Use the new cpumask_or_equal() function to simplify the decision whether
the supplied target CPU mask is either equal to cpu_online_mask or equal to
cpu_online_mask except for the CPU on which the function is invoked.
cpumask_or_equal() or's the target mask and the cpumask of the current CPU
together and compares it to cpu_online_mask.
If the result is false, use the mask based IPI function, otherwise check
whether the current CPU is set in the target mask and invoke either the
send_IPI_all() or the send_IPI_allbutselt() APIC callback.
Make the shorthand decision also depend on the static key which enables
shorthand mode. That allows to remove the extra cpumask comparison with
cpu_callout_mask.
Reported-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20190722105220.768238809@linutronix.de
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Move it where it belongs. That allows to keep all the shorthand logic in
one place.
No functional change.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20190722105220.677835995@linutronix.de
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To support IPI shorthands wrap invocations of apic->send_IPI_allbutself()
in a helper function, so the static key controlling the shorthand mode is
only in one place.
Fixup all callers.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20190722105220.492691679@linutronix.de
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The IPI shorthand functionality delivers IPI/NMI broadcasts to all CPUs in
the system. This can have similar side effects as the MCE broadcasting when
CPUs are waiting in the BIOS or are offlined.
The kernel tracks already the state of offlined CPUs whether they have been
brought up at least once so that the CR4 MCE bit is set to make sure that
MCE broadcasts can't brick the machine.
Utilize that information and compare it to the cpu_present_mask. If all
present CPUs have been brought up at least once then the broadcast side
effect is mitigated by disabling regular interrupt/IPI delivery in the APIC
itself and by the cpu offline check at the begin of the NMI handler.
Use a static key to switch between broadcasting via shorthands or sending
the IPI/NMI one by one.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20190722105220.386410643@linutronix.de
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For the upcoming shorthand support for all APIC incarnations the command
line option needs to be available for 64 bit as well.
While at it, rename the control variable, make it static and mark it
__ro_after_init.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20190722105220.278327940@linutronix.de
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To support NMI shorthand broadcasts add the safe wait for ICR idle for NMI
vector delivery.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20190722105220.185838026@linutronix.de
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The SDM states:
"The destination shorthand field of the ICR allows the delivery mode to be
by-passed in favor of broadcasting the IPI to all the processors on the
system bus and/or back to itself (see Section 10.6.1, Interrupt Command
Register (ICR)). Three destination shorthands are supported: self, all
excluding self, and all including self. The destination mode is ignored
when a destination shorthand is used."
So there is no point to supply the destination mode to the shorthand
delivery function.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20190722105220.094613426@linutronix.de
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In order to support IPI/NMI broadcasting via the shorthand mechanism side
effects of shorthands need to be mitigated:
Shorthand IPIs and NMIs hit all CPUs including unplugged CPUs
Neither of those can be handled on unplugged CPUs for obvious reasons.
It would be trivial to just fully disable the APIC via the enable bit in
MSR_APICBASE. But that's not possible because clearing that bit on systems
based on the 3 wire APIC bus would require a hardware reset to bring it
back as the APIC would lose track of bus arbitration. On systems with FSB
delivery APICBASE could be disabled, but it has to be guaranteed that no
interrupt is sent to the APIC while in that state and it's not clear from
the SDM whether it still responds to INIT/SIPI messages.
Therefore stay on the safe side and switch the APIC into soft disabled mode
so it won't deliver any regular vector to the CPU.
NMIs are still propagated to the 'dead' CPUs. To mitigate that add a check
for the CPU being offline on early nmi entry and if so bail.
Note, this cannot use the stop/restart_nmi() magic which is used in the
alternatives code. A dead CPU cannot invoke nmi_enter() or anything else
due to RCU and other reasons.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/alpine.DEB.2.21.1907241723290.1791@nanos.tec.linutronix.de
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Peter Xu
Linus Torvalds
Tony W Wang-oc
Thomas Gleixner
Arnd Bergmann
Jan Beulich
Yi Wang
Kefeng Wang
Sean Christopherson
Mike Travis
Jan Stancek
Ingo Molnar
Neil Horman
Peter Zijlstra
Bandan Das
Borislav Petkov