[ Upstream commit 950b07c14e8c59444e2359f15fd70ed5112e11a0 ]

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: NChris Wilson <chris@chris-wilson.co.uk>
Acked-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Bandan Das <bsd@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NSasha Levin <sashal@kernel.org>

commit 558682b5291937a70748d36fd9ba757fb25b99ae upstream.

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: NBandan Das <bsd@redhat.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20190826101513.5080-3-bsd@redhat.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit f897e60a12f0b9146357780d317879bce2a877dc upstream.

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: NDaniel Drake <drake@endlessm.com>
Reported-by: NJiri Slaby <jslaby@suse.cz>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Tested-by: NDaniel 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#c12Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

[ Upstream commit ec6335586953b0df32f83ef696002063090c7aef ]

There are many compiler warnings like this,

In file included from ./arch/x86/include/asm/smp.h:13,
                 from ./arch/x86/include/asm/mmzone_64.h:11,
                 from ./arch/x86/include/asm/mmzone.h:5,
                 from ./include/linux/mmzone.h:969,
                 from ./include/linux/gfp.h:6,
                 from ./include/linux/mm.h:10,
                 from arch/x86/kernel/apic/io_apic.c:34:
arch/x86/kernel/apic/io_apic.c: In function 'check_timer':
./arch/x86/include/asm/apic.h:37:11: warning: comparison of unsigned
expression >= 0 is always true [-Wtype-limits]
   if ((v) <= apic_verbosity) \
           ^~
arch/x86/kernel/apic/io_apic.c:2160:2: note: in expansion of macro
'apic_printk'
  apic_printk(APIC_QUIET, KERN_INFO "..TIMER: vector=0x%02X "
  ^~~~~~~~~~~
./arch/x86/include/asm/apic.h:37:11: warning: comparison of unsigned
expression >= 0 is always true [-Wtype-limits]
   if ((v) <= apic_verbosity) \
           ^~
arch/x86/kernel/apic/io_apic.c:2207:4: note: in expansion of macro
'apic_printk'
    apic_printk(APIC_QUIET, KERN_ERR "..MP-BIOS bug: "
    ^~~~~~~~~~~

APIC_QUIET is 0, so silence them by making apic_verbosity type int.
Signed-off-by: NQian Cai <cai@lca.pw>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/1562621805-24789-1-git-send-email-cai@lca.pwSigned-off-by: NSasha Levin <sashal@kernel.org>

commit f8a8fe61fec8006575699559ead88b0b833d5cad upstream

Quite some time ago the interrupt entry stubs for unused vectors in the
system vector range got removed and directly mapped to the spurious
interrupt vector entry point.

Sounds reasonable, but it's subtly broken. The spurious interrupt vector
entry point pushes vector number 0xFF on the stack which makes the whole
logic in __smp_spurious_interrupt() pointless.

As a consequence any spurious interrupt which comes from a vector != 0xFF
is treated as a real spurious interrupt (vector 0xFF) and not
acknowledged. That subsequently stalls all interrupt vectors of equal and
lower priority, which brings the system to a grinding halt.

This can happen because even on 64-bit the system vector space is not
guaranteed to be fully populated. A full compile time handling of the
unused vectors is not possible because quite some of them are conditonally
populated at runtime.

Bring the entry stubs back, which wastes 160 bytes if all stubs are unused,
but gains the proper handling back. There is no point to selectively spare
some of the stubs which are known at compile time as the required code in
the IDT management would be way larger and convoluted.

Do not route the spurious entries through common_interrupt and do_IRQ() as
the original code did. Route it to smp_spurious_interrupt() which evaluates
the vector number and acts accordingly now that the real vector numbers are
handed in.

Fixup the pr_warn so the actual spurious vector (0xff) is clearly
distiguished from the other vectors and also note for the vectored case
whether it was pending in the ISR or not.

 "Spurious APIC interrupt (vector 0xFF) on CPU#0, should never happen."
 "Spurious interrupt vector 0xed on CPU#1. Acked."
 "Spurious interrupt vector 0xee on CPU#1. Not pending!."

Fixes: 2414e021 ("x86: Avoid building unused IRQ entry stubs")
Reported-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Jan Beulich <jbeulich@suse.com>
Link: https://lkml.kernel.org/r/20190628111440.550568228@linutronix.deSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

[ Upstream commit ea136a112d89bade596314a1ae49f748902f4727 ]

The left shift of unsigned int cpu_khz will overflow for large values of
cpu_khz, so cast it to a long long before shifting it to avoid overvlow.
For example, this can happen when cpu_khz is 4194305, i.e. ~4.2 GHz.

Addresses-Coverity: ("Unintentional integer overflow")
Fixes: 8c3ba8d0 ("x86, apic: ack all pending irqs when crashed/on kexec")
Signed-off-by: NColin Ian King <colin.king@canonical.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H . Peter Anvin" <hpa@zytor.com>
Cc: kernel-janitors@vger.kernel.org
Link: https://lkml.kernel.org/r/20190619181446.13635-1-colin.king@canonical.comSigned-off-by: NSasha Levin <sashal@kernel.org>

The function has an inline "return false;" definition with CONFIG_SMP=n
but the "real" definition is also visible leading to "redefinition of
‘apic_id_is_primary_thread’" compiler error.

Guard it with #ifdef CONFIG_SMP
Signed-off-by: NVlastimil Babka <vbabka@suse.cz>
Fixes: 6a4d2657 ("x86/smp: Provide topology_is_primary_thread()")
Cc: stable@vger.kernel.org
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The next patch in this series will have to make the definition of
irq_cpustat_t available to entering_irq().

Inclusion of asm/hardirq.h into asm/apic.h would cause circular header
dependencies like

  asm/smp.h
    asm/apic.h
      asm/hardirq.h
        linux/irq.h
          linux/topology.h
            linux/smp.h
              asm/smp.h

or

  linux/gfp.h
    linux/mmzone.h
      asm/mmzone.h
        asm/mmzone_64.h
          asm/smp.h
            asm/apic.h
              asm/hardirq.h
                linux/irq.h
                  linux/irqdesc.h
                    linux/kobject.h
                      linux/sysfs.h
                        linux/kernfs.h
                          linux/idr.h
                            linux/gfp.h

and others.

This causes compilation errors because of the header guards becoming
effective in the second inclusion: symbols/macros that had been defined
before wouldn't be available to intermediate headers in the #include chain
anymore.

A possible workaround would be to move the definition of irq_cpustat_t
into its own header and include that from both, asm/hardirq.h and
asm/apic.h.

However, this wouldn't solve the real problem, namely asm/harirq.h
unnecessarily pulling in all the linux/irq.h cruft: nothing in
asm/hardirq.h itself requires it. Also, note that there are some other
archs, like e.g. arm64, which don't have that #include in their
asm/hardirq.h.

Remove the linux/irq.h #include from x86' asm/hardirq.h.

Fix resulting compilation errors by adding appropriate #includes to *.c
files as needed.

Note that some of these *.c files could be cleaned up a bit wrt. to their
set of #includes, but that should better be done from separate patches, if
at all.
Signed-off-by: NNicolai Stange <nstange@suse.de>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

There is inconsistent indenting in calibrate_APIC_clock() and
activate_managed(). Remove the surplus TAB.
Signed-off-by: NYi Wang <wang.yi59@zte.com.cn>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NJiang Biao <jiang.biao2@zte.com.cn>
Acked-by: NSteven Rostedt (VMware) <rostedt@goodmis.org>
Cc: hpa@zytor.com
Cc: douly.fnst@cn.fujitsu.com
Cc: jgross@suse.com
Cc: ville.syrjala@linux.intel.com
Cc: len.brown@intel.com
Cc: gregkh@linuxfoundation.org
Cc: zhong.weidong@zte.com.cn
Link: https://lkml.kernel.org/r/1532672103-32250-1-git-send-email-wang.yi59@zte.com.cn

All SKX with stepping higher than 4 support the TSC_DEADLINE,
no matter the microcode version.

Without this patch, upcoming SKX steppings will not be able to use
their TSC_DEADLINE timer.
Signed-off-by: NLen Brown <len.brown@intel.com>
Cc: <stable@kernel.org> # v4.14+
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: 616dd587 ("x86/apic: Update TSC_DEADLINE quirk with additional SKX stepping")
Link: http://lkml.kernel.org/r/d0c7129e509660be9ec6b233284b8d42d90659e8.1532207856.git.len.brown@intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

Dave Hansen reported, that it's outright dangerous to keep SMT siblings
disabled completely so they are stuck in the BIOS and wait for SIPI.

The reason is that Machine Check Exceptions are broadcasted to siblings and
the soft disabled sibling has CR4.MCE = 0. If a MCE is delivered to a
logical core with CR4.MCE = 0, it asserts IERR#, which shuts down or
reboots the machine. The MCE chapter in the SDM contains the following
blurb:

    Because the logical processors within a physical package are tightly
    coupled with respect to shared hardware resources, both logical
    processors are notified of machine check errors that occur within a
    given physical processor. If machine-check exceptions are enabled when
    a fatal error is reported, all the logical processors within a physical
    package are dispatched to the machine-check exception handler. If
    machine-check exceptions are disabled, the logical processors enter the
    shutdown state and assert the IERR# signal. When enabling machine-check
    exceptions, the MCE flag in control register CR4 should be set for each
    logical processor.

Reverting the commit which ignores siblings at enumeration time solves only
half of the problem. The core cpuhotplug logic needs to be adjusted as
well.

This thoughtful engineered mechanism also turns the boot process on all
Intel HT enabled systems into a MCE lottery. MCE is enabled on the boot CPU
before the secondary CPUs are brought up. Depending on the number of
physical cores the window in which this situation can happen is smaller or
larger. On a HSW-EX it's about 750ms:

MCE is enabled on the boot CPU:

[    0.244017] mce: CPU supports 22 MCE banks

The corresponding sibling #72 boots:

[    1.008005] .... node  #0, CPUs:    #72

That means if an MCE hits on physical core 0 (logical CPUs 0 and 72)
between these two points the machine is going to shutdown. At least it's a
known safe state.

It's obvious that the early boot can be hit by an MCE as well and then runs
into the same situation because MCEs are not yet enabled on the boot CPU.
But after enabling them on the boot CPU, it does not make any sense to
prevent the kernel from recovering.

Adjust the nosmt kernel parameter documentation as well.

Reverts: 2207def7 ("x86/apic: Ignore secondary threads if nosmt=force")
Reported-by: NDave Hansen <dave.hansen@intel.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Tested-by: NTony Luck <tony.luck@intel.com>

nosmt on the kernel command line merely prevents the onlining of the
secondary SMT siblings.

nosmt=force makes the APIC detection code ignore the secondary SMT siblings
completely, so they even do not show up as possible CPUs. That reduces the
amount of memory allocations for per cpu variables and saves other
resources from being allocated too large.

This is not fully equivalent to disabling SMT in the BIOS because the low
level SMT enabling in the BIOS can result in partitioning of resources
between the siblings, which is not undone by just ignoring them. Some CPUs
can use the full resources when their sibling is not onlined, but this is
depending on the CPU family and model and it's not well documented whether
this applies to all partitioned resources. That means depending on the
workload disabling SMT in the BIOS might result in better performance.

Linus analysis of the Intel manual:

  The intel optimization manual is not very clear on what the partitioning
  rules are.

  I find:

    "In general, the buffers for staging instructions between major pipe
     stages  are partitioned. These buffers include µop queues after the
     execution trace cache, the queues after the register rename stage, the
     reorder buffer which stages instructions for retirement, and the load
     and store buffers.

     In the case of load and store buffers, partitioning also provided an
     easier implementation to maintain memory ordering for each logical
     processor and detect memory ordering violations"

  but some of that partitioning may be relaxed if the HT thread is "not
  active":

    "In Intel microarchitecture code name Sandy Bridge, the micro-op queue
     is statically partitioned to provide 28 entries for each logical
     processor,  irrespective of software executing in single thread or
     multiple threads. If one logical processor is not active in Intel
     microarchitecture code name Ivy Bridge, then a single thread executing
     on that processor  core can use the 56 entries in the micro-op queue"

  but I do not know what "not active" means, and how dynamic it is. Some of
  that partitioning may be entirely static and depend on the early BIOS
  disabling of HT, and even if we park the cores, the resources will just be
  wasted.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: NIngo Molnar <mingo@kernel.org>

If the CPU is supporting SMT then the primary thread can be found by
checking the lower APIC ID bits for zero. smp_num_siblings is used to build
the mask for the APIC ID bits which need to be taken into account.

This uses the MPTABLE or ACPI/MADT supplied APIC ID, which can be different
than the initial APIC ID in CPUID. But according to AMD the lower bits have
to be consistent. Intel gave a tentative confirmation as well.

Preparatory patch to support disabling SMT at boot/runtime.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: NIngo Molnar <mingo@kernel.org>

The logical_smp_processor_id() inline which is only called in
setup_local_APIC() on x86_32 systems has no real value.

Drop it and directly use GET_APIC_LOGICAL_ID() at the call site and use a
more suitable variable name for readability
Signed-off-by: NDou Liyang <douly.fnst@cn.fujitsu.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: andy.shevchenko@gmail.com
Cc: bhe@redhat.com
Cc: ebiederm@xmission.com
Link: https://lkml.kernel.org/r/20180301055930.2396-4-douly.fnst@cn.fujitsu.com

The pending interrupt check code is old, update the following:

  - Use for_each_set_bit() instead of open coding it
  - Replace printk() with pr_err()
  - Get rid of printk line breaks
  - Make curly braces balanced
Suggested-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: NDou Liyang <douly.fnst@cn.fujitsu.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Cc: bhe@redhat.com
Cc: ebiederm@xmission.com
Link: https://lkml.kernel.org/r/20180301055930.2396-3-douly.fnst@cn.fujitsu.com

The pending interrupt check code is mixed with the local APIC setup code,
that looks messy.

Extract the related code, move it into a new function named
apic_pending_intr_clear().
Signed-off-by: NDou Liyang <douly.fnst@cn.fujitsu.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Cc: bhe@redhat.com
Cc: ebiederm@xmission.com
Link: https://lkml.kernel.org/r/20180301055930.2396-2-douly.fnst@cn.fujitsu.com

Currently the kdump kernel becomes very slow if 'noapic' is specified.
Normal kernel doesn't have this bug.

Kernel parameter 'noapic' is used to disable IO-APIC in system for
testing or special purpose. Here the root cause is that in kdump
kernel LAPIC is disabled since commit:

  522e6646 ("x86/apic: Disable I/O APIC before shutdown of the local APIC")

In this case we need set up through-local-APIC on boot CPU in
setup_local_APIC().

In normal kernel the legacy irq mode is enabled by the BIOS. If
it is virtual wire mode, the local-APIC has been enabled and set as
through-local-APIC.

Though we fixed the regression introduced by commit 522e6646,
to further improve robustness set up the through-local-APIC mode
explicitly, do not rely on the default boot IRQ mode.
Signed-off-by: NBaoquan He <bhe@redhat.com>
Reviewed-by: NEric W. Biederman <ebiederm@xmission.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: douly.fnst@cn.fujitsu.com
Cc: joro@8bytes.org
Cc: prarit@redhat.com
Cc: uobergfe@redhat.com
Link: http://lkml.kernel.org/r/20180214054656.3780-7-bhe@redhat.com
[ Rewrote the changelog. ]
Signed-off-by: NIngo Molnar <mingo@kernel.org>

This function isn't used outside of apic.c, so let's mark it static.
Signed-off-by: NDou Liyang <douly.fnst@cn.fujitsu.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: bhe@redhat.com
Cc: ebiederm@xmission.com
Link: http://lkml.kernel.org/r/20180214062554.21020-1-douly.fnst@cn.fujitsu.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

x86_mask is a confusing name which is hard to associate with the
processor's stepping.

Additionally, correct an indent issue in lib/cpu.c.
Signed-off-by: NJia Zhang <qianyue.zj@alibaba-inc.com>
[ Updated it to more recent kernels. ]
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: bp@alien8.de
Cc: tony.luck@intel.com
Link: http://lkml.kernel.org/r/1514771530-70829-1-git-send-email-qianyue.zj@alibaba-inc.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

This reverts commit b371ae0d. It causes
boot hangs on old P3/P4 systems when the local APIC is enforced in UP mode.
Reported-by: NMeelis Roos <mroos@linux.ee>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Dou Liyang <douly.fnst@cn.fujitsu.com>
Cc: yinghai@kernel.org
Cc: bhe@redhat.com
Link: https://lkml.kernel.org/r/20171128145350.21560-1-ville.syrjala@linux.intel.com

There are two consumers of apic=:
  apic_set_verbosity() for setting the APIC debug level;
  parse_apic() for registering APIC driver by hand.

X86-32 supports both of them, but sometimes, kernel issues a weird warning.
eg: when kernel was booted up with 'apic=bigsmp' in command line,
early_param would warn like that:

...
[    0.000000] APIC Verbosity level bigsmp not recognised use apic=verbose or apic=debug
[    0.000000] Malformed early option 'apic'
...

Wrap the warning code in CONFIG_X86_64 case to avoid this.
Signed-off-by: NDou Liyang <douly.fnst@cn.fujitsu.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: peterz@infradead.org
Cc: rdunlap@infradead.org
Cc: corbet@lwn.net
Link: https://lkml.kernel.org/r/20171204040313.24824-1-douly.fnst@cn.fujitsu.com

Instead of x86_hyper being either NULL on bare metal or a pointer to a
struct hypervisor_x86 in case of the kernel running as a guest merge
the struct into x86_platform and x86_init.

This will remove the need for wrappers making it hard to find out what
is being called. With dummy functions added for all callbacks testing
for a NULL function pointer can be removed, too.
Suggested-by: NIngo Molnar <mingo@kernel.org>
Signed-off-by: NJuergen Gross <jgross@suse.com>
Acked-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: akataria@vmware.com
Cc: boris.ostrovsky@oracle.com
Cc: devel@linuxdriverproject.org
Cc: haiyangz@microsoft.com
Cc: kvm@vger.kernel.org
Cc: kys@microsoft.com
Cc: pbonzini@redhat.com
Cc: rkrcmar@redhat.com
Cc: rusty@rustcorp.com.au
Cc: sthemmin@microsoft.com
Cc: virtualization@lists.linux-foundation.org
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/20171109132739.23465-2-jgross@suse.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

SKX stepping-3 fixed the TSC_DEADLINE issue in a different ucode
version number than stepping-4.  Linux needs to know this stepping-3
specific version number to also enable the TSC_DEADLINE on stepping-3.

The steppings and ucode versions are documented in the SKX BIOS update:
https://downloadmirror.intel.com/26978/eng/ReleaseNotes_R00.01.0004.txtSigned-off-by: NLen Brown <len.brown@intel.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: peterz@infradead.org
Link: https://lkml.kernel.org/r/60f2bbf7cf617e212b522e663f84225bfebc50e5.1507756305.git.len.brown@intel.com

Commit 594a30fb ("x86/apic: Silence "FW_BUG TSC_DEADLINE disabled
due to Errata" on CPUs without the feature", 2017-08-30) was also about
silencing the warning on VirtualBox; however, KVM does expose the TSC
deadline timer, and it's virtualized so that it is immune from CPU errata.

Therefore, booting 4.13 with "-cpu Haswell" shows this in the logs:

     [    0.000000] [Firmware Bug]: TSC_DEADLINE disabled due to Errata;
                    please update microcode to version: 0xb2 (or later)

Even if you had a hypervisor that does _not_ virtualize the TSC deadline
and rather exposes the hardware one, it should be the hypervisors task
to update microcode and possibly hide the flag from CPUID.  So just
hide the message when running on _any_ hypervisor, not just those that
do not support the TSC deadline timer.

The older check still makes sense, so keep it.

Fixes: bd9240a1 ("x86/apic: Add TSC_DEADLINE quirk due to errata")
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: kvm@vger.kernel.org
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/1507630377-54471-1-git-send-email-pbonzini@redhat.com

It's not obvious to everybody that BP stands for boot processor. At
least it was not for me. And BP is also a CPU register on x86, so it
is ambiguous. Spell out "boot CPU" everywhere instead.
Signed-off-by: NJean Delvare <jdelvare@suse.de>
Cc: Alok Kataria <akataria@vmware.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: NIngo Molnar <mingo@kernel.org>

Trivial fix to spelling mistakes in pr_info messages
Signed-off-by: NColin Ian King <colin.king@canonical.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Dou Liyang <douly.fnst@cn.fujitsu.com>
Link: https://lkml.kernel.org/r/20170927102223.31920-1-colin.king@canonical.com

Move more apic struct specific functions out of the header and the apic
management code into the common source file.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Tested-by: NJuergen Gross <jgross@suse.com>
Tested-by: NYu Chen <yu.c.chen@intel.com>
Acked-by: NJuergen Gross <jgross@suse.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Alok Kataria <akataria@vmware.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Rui Zhang <rui.zhang@intel.com>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Len Brown <lenb@kernel.org>
Link: https://lkml.kernel.org/r/20170913213153.834421893@linutronix.de

The apic functions which are used in probe_32.c are implemented as inlines
or in apic.c. There is no reason to have them at random places.

Move them to the actual usage site and make them static.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Tested-by: NJuergen Gross <jgross@suse.com>
Tested-by: NYu Chen <yu.c.chen@intel.com>
Acked-by: NJuergen Gross <jgross@suse.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Alok Kataria <akataria@vmware.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Rui Zhang <rui.zhang@intel.com>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Len Brown <lenb@kernel.org>
Link: https://lkml.kernel.org/r/20170913213153.596768194@linutronix.de

lapic_is_integrated() is a wrapper around APIC_INTEGRATED(), but not used
consistently.

Replace the direct usage of APIC_INTEGRATED() and fixup a hard to read tail
comment. No functional change.

[ tglx: Made it compile and work .... ]
Signed-off-by: NDou Liyang <douly.fnst@cn.fujitsu.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: bhe@redhat.com
Link: https://lkml.kernel.org/r/1504774161-7137-2-git-send-email-douly.fnst@cn.fujitsu.com

The macro APIC_INTEGRATED(x) is already wrapped by CONFIG_X86_32. So
it can be invoked unconditionally.

Remove the extra "#ifdef CONFIG_X86_64...". No functional change.
Signed-off-by: NDou Liyang <douly.fnst@cn.fujitsu.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: bhe@redhat.com
Link: https://lkml.kernel.org/r/1504774161-7137-1-git-send-email-douly.fnst@cn.fujitsu.com

init_bsp_APIC() which works for the virtual wire mode is used in ISA irq
initialization at boot time.

With the new APIC interrupt delivery mode scheme, which initializes the
APIC before the first interrupt is expected, init_bsp_APIC() is not longer
required and can be removed.
Signed-off-by: NDou Liyang <douly.fnst@cn.fujitsu.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: yinghai@kernel.org
Cc: bhe@redhat.com
Link: https://lkml.kernel.org/r/1505293975-26005-13-git-send-email-douly.fnst@cn.fujitsu.com

A cold or warm boot through BIOS sets the APIC in default interrupt
delivery mode. A dump-capture kernel will not go through a BIOS reset and
leave the interrupt delivery mode in the state which was active on the
crashed kernel, but the dump kernel startup code assumes default delivery
mode which can result in interrupt delivery/handling to fail.

To solve this problem, it's required to set up the final interrupt delivery
mode as soon as possible. As IOAPIC setup needs the timer initialized for
verifying the timer interrupt delivery mode, the earliest point is right
after timer setup in late_time_init().

That results in the following init order:

  1) Set up the legacy timer, if applicable on the platform

  2) Set up APIC/IOAPIC which includes the verification of the legacy timer
     interrupt delivery.

  3) TSC calibration

  4) Local APIC timer setup
Signed-off-by: NDou Liyang <douly.fnst@cn.fujitsu.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: yinghai@kernel.org
Cc: bhe@redhat.com
Link: https://lkml.kernel.org/r/1505293975-26005-12-git-send-email-douly.fnst@cn.fujitsu.com

X86 and XEN initialize interrupt delivery mode in different way.

To avoid conditionals, add a new x86_init_ops function which defaults to
the standard function and can be overridden by the early XEN platform code.

[ tglx: Folded the XEN part which was a separate patch to preserve
  	bisectability ]
Signed-off-by: NDou Liyang <douly.fnst@cn.fujitsu.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: yinghai@kernel.org
Cc: bhe@redhat.com
Link: https://lkml.kernel.org/r/1505293975-26005-10-git-send-email-douly.fnst@cn.fujitsu.com

In UniProcessor kernel with UP_LATE_INIT=y, the interrupt delivery mode is
initialized in up_late_init().

Use the new unified apic_intr_mode_init() function and remove
APIC_init_uniprocessor().
Signed-off-by: NDou Liyang <douly.fnst@cn.fujitsu.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: yinghai@kernel.org
Cc: bhe@redhat.com
Link: https://lkml.kernel.org/r/1505293975-26005-8-git-send-email-douly.fnst@cn.fujitsu.com

Calling native_smp_prepare_cpus() to prepare for SMP bootup, does some
sanity checking, enables APIC mode and disables SMP feature.

Now, APIC mode setup has been unified to apic_intr_mode_init(), some sanity
checks are redundant and need to be cleanup.

Mark the apic_intr_mode extern to refine the switch and remove the
redundant sanity check.
Signed-off-by: NDou Liyang <douly.fnst@cn.fujitsu.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: yinghai@kernel.org
Cc: bhe@redhat.com
Link: https://lkml.kernel.org/r/1505293975-26005-7-git-send-email-douly.fnst@cn.fujitsu.com

On a SMP-capable system, the kernel enables and sets up the APIC interrupt
delivery mode in native_smp_prepare_cpus(). The decision how to setup the
APIC is intermingled with the decision of setting up SMP or not.

Split the initialization of the APIC interrupt mode independent from other
decisions and have a separate apic_intr_mode_init() function for it.

The invocation time stays the same for now.
Signed-off-by: NDou Liyang <douly.fnst@cn.fujitsu.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: yinghai@kernel.org
Cc: bhe@redhat.com
Link: https://lkml.kernel.org/r/1505293975-26005-6-git-send-email-douly.fnst@cn.fujitsu.com

apic_bsp_setup() sets and returns logical APIC ID for initializing
cpu0_logical_apicid in a SMP-capable system.

The id has nothing to do with the initialization of local APIC and I/O
APIC. And apic_bsp_setup() should be called for interrupt mode setup only.

Move the id setup into a separate helper function for cleanup and mark
apic_bsp_setup() void.
Signed-off-by: NDou Liyang <douly.fnst@cn.fujitsu.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: yinghai@kernel.org
Cc: bhe@redhat.com
Link: https://lkml.kernel.org/r/1505293975-26005-5-git-send-email-douly.fnst@cn.fujitsu.com

apic_bsp_setup() sets up the local APIC, I/O APIC and APIC timer.

The local APIC and I/O APIC setup belongs to interrupt delivery mode
setup. Setting up the local APIC timer for booting CPU is another job
and has nothing to do with interrupt delivery mode setup.

Split local APIC timer setup from the APIC setup, keep it in the original
position for SMP and UP kernel for now.
Signed-off-by: NDou Liyang <douly.fnst@cn.fujitsu.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: yinghai@kernel.org
Cc: bhe@redhat.com
Link: https://lkml.kernel.org/r/1505293975-26005-4-git-send-email-douly.fnst@cn.fujitsu.com

There are three places which initialize the interrupt delivery modes:

1) init_bsp_APIC() which is called early might setup the through-local-APIC
   virtual wire mode on non SMP systems.

2) In an SMP-capable system, native_smp_prepare_cpus() tries to switch to
   symmetric I/O model.

3) In UP system with UP_LATE_INIT=y, the local APIC and I/O APIC are set up
   in smp_init().

There is no technical reason to make these initializations at random places
and run the kernel with the potentially wrong mode through the early boot
stage, but it has a problematic side effect: The late switch to symmetric
I/O mode causes dump-capture kernel to hang when the kernel command line
option 'notsc' is active.

Provide a new function to unify that three positions. Preparatory patch to
initialize an interrupt mode directly.
Signed-off-by: NDou Liyang <douly.fnst@cn.fujitsu.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: yinghai@kernel.org
Cc: bhe@redhat.com
Link: https://lkml.kernel.org/r/1505293975-26005-3-git-send-email-douly.fnst@cn.fujitsu.com

There are quite some switches which are used to determine the final
interrupt delivery mode, as shown below:

1) Kconfig: CONFIG_X86_64; CONFIG_X86_LOCAL_APIC; CONFIG_x86_IO_APIC
2) Command line options: disable_apic; skip_ioapic_setup
3) CPU Capability: boot_cpu_has(X86_FEATURE_APIC)
4) MP table: smp_found_config
5) ACPI: acpi_lapic; acpi_ioapic; nr_ioapic

These switches are disordered and scattered and there are also some
dependencies between them. These make the code difficult to maintain and
read.

Construct a selector to unify them into a single function, then, Use this
selector to get an interrupt delivery mode directly.
Signed-off-by: NDou Liyang <douly.fnst@cn.fujitsu.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: yinghai@kernel.org
Cc: bhe@redhat.com
Link: https://lkml.kernel.org/r/1505293975-26005-2-git-send-email-douly.fnst@cn.fujitsu.com