6 Commits

Author SHA1 Message Date
Thomas Gleixner
43931d350f x86/apic/x2apic: Implement IPI shorthands support
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
2019-07-25 16:12:02 +02:00
Thomas Gleixner
dea978632e x86/apic: Share common IPI helpers
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
2019-07-25 16:12:02 +02:00
Thomas Gleixner
6a1cb5f5c6 x86/apic: Add static key to Control IPI shorthands
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
2019-07-25 16:12:00 +02:00
Thomas Gleixner
bdda3b93e6 x86/apic: Move no_ipi_broadcast() out of 32bit
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
2019-07-25 16:12:00 +02:00
Thomas Gleixner
3994ff90ac x86/apic: Remove dest argument from __default_send_IPI_shortcut()
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
2019-07-25 16:11:59 +02:00
Thomas Gleixner
c94f0718fb x86/apic: Consolidate the apic local headers
Now there are three small local headers. Some contain functions which are
only used in one source file.

Move all the inlines and declarations into a single local header and the
inlines which are only used in one source file into that.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20190722105219.618612624@linutronix.de
2019-07-25 16:11:58 +02:00