<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/arch/x86/kernel/apic/apic.c, branch v5.19</title>
<subtitle>Linux kernel for Apalis and Colibri modules</subtitle>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/'/>
<entry>
<title>Merge tag 'x86_misc_for_v5.19_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip</title>
<updated>2022-05-24T02:32:59+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2022-05-24T02:32:59+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=abc8babefbc1fc6f013573bc933d66bc906cf726'/>
<id>abc8babefbc1fc6f013573bc933d66bc906cf726</id>
<content type='text'>
Pull misc x86 updates from Borislav Petkov:
 "A variety of fixes which don't fit any other tip bucket:

   - Remove unnecessary function export

   - Correct asm constraint

   - Fix __setup handlers retval"

* tag 'x86_misc_for_v5.19_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/mm: Cleanup the control_va_addr_alignment() __setup handler
  x86: Fix return value of __setup handlers
  x86/delay: Fix the wrong asm constraint in delay_loop()
  x86/amd_nb: Unexport amd_cache_northbridges()
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull misc x86 updates from Borislav Petkov:
 "A variety of fixes which don't fit any other tip bucket:

   - Remove unnecessary function export

   - Correct asm constraint

   - Fix __setup handlers retval"

* tag 'x86_misc_for_v5.19_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/mm: Cleanup the control_va_addr_alignment() __setup handler
  x86: Fix return value of __setup handlers
  x86/delay: Fix the wrong asm constraint in delay_loop()
  x86/amd_nb: Unexport amd_cache_northbridges()
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'x86_apic_for_v5.19_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip</title>
<updated>2022-05-24T02:16:09+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2022-05-24T02:16:09+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=916654201008d5fb4d5f5dcf0b373d291da615ac'/>
<id>916654201008d5fb4d5f5dcf0b373d291da615ac</id>
<content type='text'>
Pull x86 APIC updates from Borislav Petkov:

 - Always do default APIC routing setup so that cpumasks are properly
   allocated and are present when later accessed ("nosmp" and x2APIC)

 - Clarify the bit overlap between an old APIC and a modern, integrated
   one

* tag 'x86_apic_for_v5.19_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/apic: Do apic driver probe for "nosmp" use case
  x86/apic: Clarify i82489DX bit overlap in APIC_LVT0
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull x86 APIC updates from Borislav Petkov:

 - Always do default APIC routing setup so that cpumasks are properly
   allocated and are present when later accessed ("nosmp" and x2APIC)

 - Clarify the bit overlap between an old APIC and a modern, integrated
   one

* tag 'x86_apic_for_v5.19_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/apic: Do apic driver probe for "nosmp" use case
  x86/apic: Clarify i82489DX bit overlap in APIC_LVT0
</pre>
</div>
</content>
</entry>
<entry>
<title>x86: Fix return value of __setup handlers</title>
<updated>2022-05-04T14:47:57+00:00</updated>
<author>
<name>Randy Dunlap</name>
<email>rdunlap@infradead.org</email>
</author>
<published>2022-03-14T01:27:25+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=12441ccdf5e2f5a01a46e344976cbbd3d46845c9'/>
<id>12441ccdf5e2f5a01a46e344976cbbd3d46845c9</id>
<content type='text'>
__setup() handlers should return 1 to obsolete_checksetup() in
init/main.c to indicate that the boot option has been handled. A return
of 0 causes the boot option/value to be listed as an Unknown kernel
parameter and added to init's (limited) argument (no '=') or environment
(with '=') strings. So return 1 from these x86 __setup handlers.

Examples:

  Unknown kernel command line parameters "apicpmtimer
    BOOT_IMAGE=/boot/bzImage-517rc8 vdso=1 ring3mwait=disable", will be
    passed to user space.

  Run /sbin/init as init process
   with arguments:
     /sbin/init
     apicpmtimer
   with environment:
     HOME=/
     TERM=linux
     BOOT_IMAGE=/boot/bzImage-517rc8
     vdso=1
     ring3mwait=disable

Fixes: 2aae950b21e4 ("x86_64: Add vDSO for x86-64 with gettimeofday/clock_gettime/getcpu")
Fixes: 77b52b4c5c66 ("x86: add "debugpat" boot option")
Fixes: e16fd002afe2 ("x86/cpufeature: Enable RING3MWAIT for Knights Landing")
Fixes: b8ce33590687 ("x86_64: convert to clock events")
Reported-by: Igor Zhbanov &lt;i.zhbanov@omprussia.ru&gt;
Signed-off-by: Randy Dunlap &lt;rdunlap@infradead.org&gt;
Signed-off-by: Borislav Petkov &lt;bp@suse.de&gt;
Link: https://lore.kernel.org/r/64644a2f-4a20-bab3-1e15-3b2cdd0defe3@omprussia.ru
Link: https://lore.kernel.org/r/20220314012725.26661-1-rdunlap@infradead.org
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
__setup() handlers should return 1 to obsolete_checksetup() in
init/main.c to indicate that the boot option has been handled. A return
of 0 causes the boot option/value to be listed as an Unknown kernel
parameter and added to init's (limited) argument (no '=') or environment
(with '=') strings. So return 1 from these x86 __setup handlers.

Examples:

  Unknown kernel command line parameters "apicpmtimer
    BOOT_IMAGE=/boot/bzImage-517rc8 vdso=1 ring3mwait=disable", will be
    passed to user space.

  Run /sbin/init as init process
   with arguments:
     /sbin/init
     apicpmtimer
   with environment:
     HOME=/
     TERM=linux
     BOOT_IMAGE=/boot/bzImage-517rc8
     vdso=1
     ring3mwait=disable

Fixes: 2aae950b21e4 ("x86_64: Add vDSO for x86-64 with gettimeofday/clock_gettime/getcpu")
Fixes: 77b52b4c5c66 ("x86: add "debugpat" boot option")
Fixes: e16fd002afe2 ("x86/cpufeature: Enable RING3MWAIT for Knights Landing")
Fixes: b8ce33590687 ("x86_64: convert to clock events")
Reported-by: Igor Zhbanov &lt;i.zhbanov@omprussia.ru&gt;
Signed-off-by: Randy Dunlap &lt;rdunlap@infradead.org&gt;
Signed-off-by: Borislav Petkov &lt;bp@suse.de&gt;
Link: https://lore.kernel.org/r/64644a2f-4a20-bab3-1e15-3b2cdd0defe3@omprussia.ru
Link: https://lore.kernel.org/r/20220314012725.26661-1-rdunlap@infradead.org
</pre>
</div>
</content>
</entry>
<entry>
<title>x86/apic: Do apic driver probe for "nosmp" use case</title>
<updated>2022-05-01T20:40:29+00:00</updated>
<author>
<name>Kuppuswamy Sathyanarayanan</name>
<email>sathyanarayanan.kuppuswamy@linux.intel.com</email>
</author>
<published>2022-04-16T02:45:32+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=7a116a2dd32d96869f0f93bac00b900859ba0434'/>
<id>7a116a2dd32d96869f0f93bac00b900859ba0434</id>
<content type='text'>
For the "nosmp" use case, the APIC initialization code selects
"APIC_SYMMETRIC_IO_NO_ROUTING" as the default interrupt mode and avoids
probing APIC drivers.

This works well for the default APIC modes, but for the x2APIC case the
probe function is required to allocate the cluster_hotplug mask. So in the
APIC_SYMMETRIC_IO_NO_ROUTING case when the x2APIC is initialized it
dereferences a NULL pointer and the kernel crashes.

This was observed on a TDX platform where x2APIC is enabled and "nosmp"
command line option is allowed.

To fix this issue, probe APIC drivers via default_setup_apic_routing() for
the APIC_SYMMETRIC_IO_NO_ROUTING interrupt mode too.

Suggested-by: Kirill A. Shutemov &lt;kirill.shutemov@linux.intel.com&gt;
Suggested-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Signed-off-by: Kuppuswamy Sathyanarayanan &lt;sathyanarayanan.kuppuswamy@linux.intel.com&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Reviewed-by: Tony Luck &lt;tony.luck@intel.com&gt;
Link: https://lore.kernel.org/r/a64f864e1114bcd63593286aaf61142cfce384ea.1650076869.git.sathyanarayanan.kuppuswamy@intel.com

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
For the "nosmp" use case, the APIC initialization code selects
"APIC_SYMMETRIC_IO_NO_ROUTING" as the default interrupt mode and avoids
probing APIC drivers.

This works well for the default APIC modes, but for the x2APIC case the
probe function is required to allocate the cluster_hotplug mask. So in the
APIC_SYMMETRIC_IO_NO_ROUTING case when the x2APIC is initialized it
dereferences a NULL pointer and the kernel crashes.

This was observed on a TDX platform where x2APIC is enabled and "nosmp"
command line option is allowed.

To fix this issue, probe APIC drivers via default_setup_apic_routing() for
the APIC_SYMMETRIC_IO_NO_ROUTING interrupt mode too.

Suggested-by: Kirill A. Shutemov &lt;kirill.shutemov@linux.intel.com&gt;
Suggested-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Signed-off-by: Kuppuswamy Sathyanarayanan &lt;sathyanarayanan.kuppuswamy@linux.intel.com&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Reviewed-by: Tony Luck &lt;tony.luck@intel.com&gt;
Link: https://lore.kernel.org/r/a64f864e1114bcd63593286aaf61142cfce384ea.1650076869.git.sathyanarayanan.kuppuswamy@intel.com

</pre>
</div>
</content>
</entry>
<entry>
<title>x86/apic: Clarify i82489DX bit overlap in APIC_LVT0</title>
<updated>2022-04-13T16:39:48+00:00</updated>
<author>
<name>Thomas Gleixner</name>
<email>tglx@linutronix.de</email>
</author>
<published>2022-04-12T20:34:21+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=daf3af4705ba8f49d33ea9b7bafdc9fd9efd49e0'/>
<id>daf3af4705ba8f49d33ea9b7bafdc9fd9efd49e0</id>
<content type='text'>
Daniel stumbled over the bit overlap of the i82498DX external APIC and the
TSC deadline timer configuration bit in modern APICs, which is neither
documented in the code nor in the current SDM. Maciej provided links to
the original i82489DX/486 documentation. See Link.

Remove the i82489DX macro maze, use a i82489DX specific define in the apic
code and document the overlap in a comment.

Reported-by: Daniel Vacek &lt;neelx@redhat.com&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Maciej W. Rozycki &lt;macro@orcam.me.uk&gt;
Link: https://lore.kernel.org/r/87ee22f3ci.ffs@tglx
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Daniel stumbled over the bit overlap of the i82498DX external APIC and the
TSC deadline timer configuration bit in modern APICs, which is neither
documented in the code nor in the current SDM. Maciej provided links to
the original i82489DX/486 documentation. See Link.

Remove the i82489DX macro maze, use a i82489DX specific define in the apic
code and document the overlap in a comment.

Reported-by: Daniel Vacek &lt;neelx@redhat.com&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Maciej W. Rozycki &lt;macro@orcam.me.uk&gt;
Link: https://lore.kernel.org/r/87ee22f3ci.ffs@tglx
</pre>
</div>
</content>
</entry>
<entry>
<title>x86/acpi/x86/boot: Add multiprocessor wake-up support</title>
<updated>2022-04-07T15:27:53+00:00</updated>
<author>
<name>Kuppuswamy Sathyanarayanan</name>
<email>sathyanarayanan.kuppuswamy@linux.intel.com</email>
</author>
<published>2022-04-05T23:29:30+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=f39642d0dbacded8b4a816a9197a73efb74e5702'/>
<id>f39642d0dbacded8b4a816a9197a73efb74e5702</id>
<content type='text'>
Secondary CPU startup is currently performed with something called
the "INIT/SIPI protocol".  This protocol requires assistance from
VMMs to boot guests.  As should be a familiar story by now, that
support can not be provded to TDX guests because TDX VMMs are
not trusted by guests.

To remedy this situation a new[1] "Multiprocessor Wakeup Structure"
has been added to to an existing ACPI table (MADT).  This structure
provides the physical address of a "mailbox".  A write to the mailbox
then steers the secondary CPU to the boot code.

Add ACPI MADT wake structure parsing support and wake support.  Use
this support to wake CPUs whenever it is present instead of INIT/SIPI.

While this structure can theoretically be used on 32-bit kernels,
there are no 32-bit TDX guest kernels.  It has not been tested and
can not practically *be* tested on 32-bit.  Make it 64-bit only.

1. Details about the new structure can be found in ACPI v6.4, in the
   "Multiprocessor Wakeup Structure" section.

Co-developed-by: Sean Christopherson &lt;sean.j.christopherson@intel.com&gt;
Signed-off-by: Sean Christopherson &lt;sean.j.christopherson@intel.com&gt;
Signed-off-by: Kuppuswamy Sathyanarayanan &lt;sathyanarayanan.kuppuswamy@linux.intel.com&gt;
Signed-off-by: Kirill A. Shutemov &lt;kirill.shutemov@linux.intel.com&gt;
Signed-off-by: Dave Hansen &lt;dave.hansen@linux.intel.com&gt;
Reviewed-by: Andi Kleen &lt;ak@linux.intel.com&gt;
Reviewed-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Reviewed-by: Dave Hansen &lt;dave.hansen@linux.intel.com&gt;
Link: https://lkml.kernel.org/r/20220405232939.73860-22-kirill.shutemov@linux.intel.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Secondary CPU startup is currently performed with something called
the "INIT/SIPI protocol".  This protocol requires assistance from
VMMs to boot guests.  As should be a familiar story by now, that
support can not be provded to TDX guests because TDX VMMs are
not trusted by guests.

To remedy this situation a new[1] "Multiprocessor Wakeup Structure"
has been added to to an existing ACPI table (MADT).  This structure
provides the physical address of a "mailbox".  A write to the mailbox
then steers the secondary CPU to the boot code.

Add ACPI MADT wake structure parsing support and wake support.  Use
this support to wake CPUs whenever it is present instead of INIT/SIPI.

While this structure can theoretically be used on 32-bit kernels,
there are no 32-bit TDX guest kernels.  It has not been tested and
can not practically *be* tested on 32-bit.  Make it 64-bit only.

1. Details about the new structure can be found in ACPI v6.4, in the
   "Multiprocessor Wakeup Structure" section.

Co-developed-by: Sean Christopherson &lt;sean.j.christopherson@intel.com&gt;
Signed-off-by: Sean Christopherson &lt;sean.j.christopherson@intel.com&gt;
Signed-off-by: Kuppuswamy Sathyanarayanan &lt;sathyanarayanan.kuppuswamy@linux.intel.com&gt;
Signed-off-by: Kirill A. Shutemov &lt;kirill.shutemov@linux.intel.com&gt;
Signed-off-by: Dave Hansen &lt;dave.hansen@linux.intel.com&gt;
Reviewed-by: Andi Kleen &lt;ak@linux.intel.com&gt;
Reviewed-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Reviewed-by: Dave Hansen &lt;dave.hansen@linux.intel.com&gt;
Link: https://lkml.kernel.org/r/20220405232939.73860-22-kirill.shutemov@linux.intel.com
</pre>
</div>
</content>
</entry>
<entry>
<title>x86: Add support for 0x22/0x23 port I/O configuration space</title>
<updated>2021-08-10T21:31:43+00:00</updated>
<author>
<name>Maciej W. Rozycki</name>
<email>macro@orcam.me.uk</email>
</author>
<published>2021-07-20T03:27:49+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=fb6a0408eac284688d5262519cbb3be0250e4caf'/>
<id>fb6a0408eac284688d5262519cbb3be0250e4caf</id>
<content type='text'>
Define macros and accessors for the configuration space addressed 
indirectly with an index register and a data register at the port I/O 
locations of 0x22 and 0x23 respectively.

This space is defined by the Intel MultiProcessor Specification for the 
IMCR register used to switch between the PIC and the APIC mode[1], by 
Cyrix processors for their configuration[2][3], and also some chipsets.

Given the lack of atomicity with the indirect addressing a spinlock is 
required to protect accesses, although for Cyrix processors it is enough 
if accesses are executed with interrupts locally disabled, because the 
registers are local to the accessing CPU, and IMCR is only ever poked at 
by the BSP and early enough for interrupts not to have been configured 
yet.  Therefore existing code does not have to change or use the new 
spinlock and neither it does.

Put the spinlock in a library file then, so that it does not get pulled 
unnecessarily for configurations that do not refer it.

Convert Cyrix accessors to wrappers so as to retain the brevity and 
clarity of the `getCx86' and `setCx86' calls.

References:

[1] "MultiProcessor Specification", Version 1.4, Intel Corporation, 
    Order Number: 242016-006, May 1997, Section 3.6.2.1 "PIC Mode", pp. 
    3-7, 3-8

[2] "5x86 Microprocessor", Cyrix Corporation, Order Number: 94192-00, 
    July 1995, Section 2.3.2.4 "Configuration Registers", p. 2-23

[3] "6x86 Processor", Cyrix Corporation, Order Number: 94175-01, March 
    1996, Section 2.4.4 "6x86 Configuration Registers", p. 2-23

Signed-off-by: Maciej W. Rozycki &lt;macro@orcam.me.uk&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Link: https://lore.kernel.org/r/alpine.DEB.2.21.2107182353140.9461@angie.orcam.me.uk

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Define macros and accessors for the configuration space addressed 
indirectly with an index register and a data register at the port I/O 
locations of 0x22 and 0x23 respectively.

This space is defined by the Intel MultiProcessor Specification for the 
IMCR register used to switch between the PIC and the APIC mode[1], by 
Cyrix processors for their configuration[2][3], and also some chipsets.

Given the lack of atomicity with the indirect addressing a spinlock is 
required to protect accesses, although for Cyrix processors it is enough 
if accesses are executed with interrupts locally disabled, because the 
registers are local to the accessing CPU, and IMCR is only ever poked at 
by the BSP and early enough for interrupts not to have been configured 
yet.  Therefore existing code does not have to change or use the new 
spinlock and neither it does.

Put the spinlock in a library file then, so that it does not get pulled 
unnecessarily for configurations that do not refer it.

Convert Cyrix accessors to wrappers so as to retain the brevity and 
clarity of the `getCx86' and `setCx86' calls.

References:

[1] "MultiProcessor Specification", Version 1.4, Intel Corporation, 
    Order Number: 242016-006, May 1997, Section 3.6.2.1 "PIC Mode", pp. 
    3-7, 3-8

[2] "5x86 Microprocessor", Cyrix Corporation, Order Number: 94192-00, 
    July 1995, Section 2.3.2.4 "Configuration Registers", p. 2-23

[3] "6x86 Processor", Cyrix Corporation, Order Number: 94175-01, March 
    1996, Section 2.4.4 "6x86 Configuration Registers", p. 2-23

Signed-off-by: Maciej W. Rozycki &lt;macro@orcam.me.uk&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Link: https://lore.kernel.org/r/alpine.DEB.2.21.2107182353140.9461@angie.orcam.me.uk

</pre>
</div>
</content>
</entry>
<entry>
<title>x86/apic: Mark _all_ legacy interrupts when IO/APIC is missing</title>
<updated>2021-05-29T09:41:14+00:00</updated>
<author>
<name>Thomas Gleixner</name>
<email>tglx@linutronix.de</email>
</author>
<published>2021-05-25T11:08:41+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=7d65f9e80646c595e8c853640a9d0768a33e204c'/>
<id>7d65f9e80646c595e8c853640a9d0768a33e204c</id>
<content type='text'>
PIC interrupts do not support affinity setting and they can end up on
any online CPU. Therefore, it's required to mark the associated vectors
as system-wide reserved. Otherwise, the corresponding irq descriptors
are copied to the secondary CPUs but the vectors are not marked as
assigned or reserved. This works correctly for the IO/APIC case.

When the IO/APIC is disabled via config, kernel command line or lack of
enumeration then all legacy interrupts are routed through the PIC, but
nothing marks them as system-wide reserved vectors.

As a consequence, a subsequent allocation on a secondary CPU can result in
allocating one of these vectors, which triggers the BUG() in
apic_update_vector() because the interrupt descriptor slot is not empty.

Imran tried to work around that by marking those interrupts as allocated
when a CPU comes online. But that's wrong in case that the IO/APIC is
available and one of the legacy interrupts, e.g. IRQ0, has been switched to
PIC mode because then marking them as allocated will fail as they are
already marked as system vectors.

Stay consistent and update the legacy vectors after attempting IO/APIC
initialization and mark them as system vectors in case that no IO/APIC is
available.

Fixes: 69cde0004a4b ("x86/vector: Use matrix allocator for vector assignment")
Reported-by: Imran Khan &lt;imran.f.khan@oracle.com&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Signed-off-by: Borislav Petkov &lt;bp@suse.de&gt;
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20210519233928.2157496-1-imran.f.khan@oracle.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
PIC interrupts do not support affinity setting and they can end up on
any online CPU. Therefore, it's required to mark the associated vectors
as system-wide reserved. Otherwise, the corresponding irq descriptors
are copied to the secondary CPUs but the vectors are not marked as
assigned or reserved. This works correctly for the IO/APIC case.

When the IO/APIC is disabled via config, kernel command line or lack of
enumeration then all legacy interrupts are routed through the PIC, but
nothing marks them as system-wide reserved vectors.

As a consequence, a subsequent allocation on a secondary CPU can result in
allocating one of these vectors, which triggers the BUG() in
apic_update_vector() because the interrupt descriptor slot is not empty.

Imran tried to work around that by marking those interrupts as allocated
when a CPU comes online. But that's wrong in case that the IO/APIC is
available and one of the legacy interrupts, e.g. IRQ0, has been switched to
PIC mode because then marking them as allocated will fail as they are
already marked as system vectors.

Stay consistent and update the legacy vectors after attempting IO/APIC
initialization and mark them as system vectors in case that no IO/APIC is
available.

Fixes: 69cde0004a4b ("x86/vector: Use matrix allocator for vector assignment")
Reported-by: Imran Khan &lt;imran.f.khan@oracle.com&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Signed-off-by: Borislav Petkov &lt;bp@suse.de&gt;
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20210519233928.2157496-1-imran.f.khan@oracle.com
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'linus' into x86/cleanups, to resolve conflict</title>
<updated>2021-03-21T21:16:08+00:00</updated>
<author>
<name>Ingo Molnar</name>
<email>mingo@kernel.org</email>
</author>
<published>2021-03-21T21:16:08+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=ca8778c45e401067cefe2abbfb8b547c30d45908'/>
<id>ca8778c45e401067cefe2abbfb8b547c30d45908</id>
<content type='text'>
Conflicts:
	arch/x86/kernel/kprobes/ftrace.c

Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Conflicts:
	arch/x86/kernel/kprobes/ftrace.c

Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>x86/apic/of: Fix CPU devicetree-node lookups</title>
<updated>2021-03-19T22:01:49+00:00</updated>
<author>
<name>Johan Hovold</name>
<email>johan@kernel.org</email>
</author>
<published>2021-03-12T09:20:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=dd926880da8dbbe409e709c1d3c1620729a94732'/>
<id>dd926880da8dbbe409e709c1d3c1620729a94732</id>
<content type='text'>
Architectures that describe the CPU topology in devicetree and do not have
an identity mapping between physical and logical CPU ids must override the
default implementation of arch_match_cpu_phys_id().

Failing to do so breaks CPU devicetree-node lookups using of_get_cpu_node()
and of_cpu_device_node_get() which several drivers rely on. It also causes
the CPU struct devices exported through sysfs to point to the wrong
devicetree nodes.

On x86, CPUs are described in devicetree using their APIC ids and those
do not generally coincide with the logical ids, even if CPU0 typically
uses APIC id 0.

Add the missing implementation of arch_match_cpu_phys_id() so that CPU-node
lookups work also with SMP.

Apart from fixing the broken sysfs devicetree-node links this likely does
not affect current users of mainline kernels on x86.

Fixes: 4e07db9c8db8 ("x86/devicetree: Use CPU description from Device Tree")
Signed-off-by: Johan Hovold &lt;johan@kernel.org&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Link: https://lore.kernel.org/r/20210312092033.26317-1-johan@kernel.org
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Architectures that describe the CPU topology in devicetree and do not have
an identity mapping between physical and logical CPU ids must override the
default implementation of arch_match_cpu_phys_id().

Failing to do so breaks CPU devicetree-node lookups using of_get_cpu_node()
and of_cpu_device_node_get() which several drivers rely on. It also causes
the CPU struct devices exported through sysfs to point to the wrong
devicetree nodes.

On x86, CPUs are described in devicetree using their APIC ids and those
do not generally coincide with the logical ids, even if CPU0 typically
uses APIC id 0.

Add the missing implementation of arch_match_cpu_phys_id() so that CPU-node
lookups work also with SMP.

Apart from fixing the broken sysfs devicetree-node links this likely does
not affect current users of mainline kernels on x86.

Fixes: 4e07db9c8db8 ("x86/devicetree: Use CPU description from Device Tree")
Signed-off-by: Johan Hovold &lt;johan@kernel.org&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Link: https://lore.kernel.org/r/20210312092033.26317-1-johan@kernel.org
</pre>
</div>
</content>
</entry>
</feed>
