x86/topology: Don't update cpu_possible_map in topo_set_cpuids()

topo_set_cpuids() updates cpu_present_map and cpu_possible map. It is
invoked during enumeration and "physical hotplug" operations. In the
latter case this results in a kernel crash because cpu_possible_map is
marked read only after init completes.

There is no reason to update cpu_possible_map in that function. During
enumeration cpu_possible_map is not relevant and gets fully initialized
after enumeration completed. On "physical hotplug" the bit is already set
because the kernel allows only CPUs to be plugged which have been
enumerated and associated to a CPU number during early boot.

Remove the bogus update of cpu_possible_map.

Fixes: 0e53e7b656cf ("x86/cpu/topology: Sanitize the APIC admission logic")
Reported-by: Jonathan Cameron <Jonathan.Cameron@Huawei.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/87ttkc6kwx.ffs@tglx

x86/topology: Handle the !APIC case gracefully

If there is no local APIC enumerated and registered then the topology
bitmaps are empty. Therefore, topology_init_possible_cpus() will die with
a division by zero exception.

Prevent this by registering a fake APIC id to populate the topology
bitmap. This also allows to use all topology query interfaces
unconditionally. It does not affect the actual APIC code because either
the local APIC address was not registered or no local APIC could be
detected.

Fixes: f1f758a80516 ("x86/topology: Add a mechanism to track topology via APIC IDs")
Reported-by: Guenter Roeck <linux@roeck-us.net>
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20240322185305.242709302@linutronix.de

x86/topology: Ignore non-present APIC IDs in a present package

Borislav reported that one of his systems has a broken MADT table which
advertises eight present APICs and 24 non-present APICs in the same
package.

The non-present ones are considered hot-pluggable by the topology
evaluation code, which is obviously bogus as there is no way to hot-plug
within the same package.

As the topology evaluation code accounts for hot-pluggable CPUs in a
package, the maximum number of cores per package is computed wrong, which
in turn causes the uncore performance counter driver to access non-existing
MSRs. It will probably confuse other entities which rely on the maximum
number of cores and threads per package too.

Cure this by ignoring hot-pluggable APIC IDs within a present package.

In theory it would be reasonable to just do this unconditionally, but then
there is this thing called reality^Wvirtualization which ruins
everything. Virtualization is the only existing user of "physical" hotplug
and the virtualization tools allow the above scenario. Whether that is
actually in use or not is unknown.

As it can be argued that the virtualization case is not affected by the
issues which exposed the reported problem, allow the bogosity if the kernel
determined that it is running in a VM for now.

Fixes: 89b0f15f408f ("x86/cpu/topology: Get rid of cpuinfo::x86_max_cores")
Reported-by: Borislav Petkov (AMD) <bp@alien8.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/87a5nbvccx.ffs@tglx

x86/apic: Build the x86 topology enumeration functions on UP APIC builds too

These functions are mostly pointless on UP, but nevertheless the
64-bit UP APIC build already depends on the existence of
topology_apply_cmdline_limits_early(), which caused a build bug,
resolve it by making them available under CONFIG_X86_LOCAL_APIC,
as their prototypes already are.

Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/cpu/topology: Provide __num_[cores|threads]_per_package

Expose properly accounted information and accessors so the fiddling with
other topology variables can be replaced.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Tested-by: Sohil Mehta <sohil.mehta@intel.com>
Link: https://lore.kernel.org/r/20240213210253.120958987@linutronix.de

x86/cpu/topology: Rename smp_num_siblings

It's really a non-intuitive name. Rename it to __max_threads_per_core which
is obvious.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Tested-by: Sohil Mehta <sohil.mehta@intel.com>
Link: https://lore.kernel.org/r/20240213210253.011307973@linutronix.de

x86/cpu/topology: Retrieve cores per package from topology bitmaps

Similar to other sizing information the number of cores per package can be
established from the topology bitmap.

Provide a function for retrieving that information and replace the buggy
hack in the CPUID evaluation with it.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Tested-by: Sohil Mehta <sohil.mehta@intel.com>
Link: https://lore.kernel.org/r/20240213210252.956858282@linutronix.de

x86/cpu/topology: Provide logical pkg/die mapping

With the topology bitmaps in place the logical package and die IDs can
trivially be retrieved by determining the bitmap weight of the relevant
topology domain level up to and including the physical ID in question.

Provide a function to that effect.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Tested-by: Sohil Mehta <sohil.mehta@intel.com>
Link: https://lore.kernel.org/r/20240213210252.846136196@linutronix.de

x86/cpu/topology: Simplify cpu_mark_primary_thread()

No point in creating a mask via fls(). smp_num_siblings is guaranteed to be
a power of 2. So just using (smp_num_siblings - 1) has the same effect.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Tested-by: Sohil Mehta <sohil.mehta@intel.com>
Link: https://lore.kernel.org/r/20240213210252.791176581@linutronix.de

x86/cpu/topology: Mop up primary thread mask handling

The early initcall to initialize the primary thread mask is not longer
required because topology_init_possible_cpus() can mark primary threads
correctly when initializing the possible and present map as the number of
SMT threads is already determined correctly.

The XENPV workaround is not longer required because XENPV now registers
fake APIC IDs which will just work like any other enumeration.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Tested-by: Sohil Mehta <sohil.mehta@intel.com>
Link: https://lore.kernel.org/r/20240213210252.736104257@linutronix.de

x86/cpu/topology: Use topology bitmaps for sizing

Now that all possible APIC IDs are tracked in the topology bitmaps, its
trivial to retrieve the real information from there.

This gets rid of the guesstimates for the maximal packages and dies per
package as the actual numbers can be determined before a single AP has been
brought up.

The number of SMT threads can now be determined correctly from the bitmaps
in all situations. Up to now a system which has SMT disabled in the BIOS
will still claim that it is SMT capable, because the lowest APIC ID bit is
reserved for that and CPUID leaf 0xb/0x1f still enumerates the SMT domain
accordingly. By calculating the bitmap weights of the SMT and the CORE
domain and setting them into relation the SMT disabled in BIOS situation
reports correctly that the system is not SMT capable.

It also handles the situation correctly when a hybrid systems boot CPU does
not have SMT as it takes the SMT capability of the APs fully into account.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Tested-by: Sohil Mehta <sohil.mehta@intel.com>
Link: https://lore.kernel.org/r/20240213210252.681709880@linutronix.de

x86/cpu/topology: Assign hotpluggable CPUIDs during init

There is no point in assigning the CPU numbers during ACPI physical
hotplug. The number of possible hotplug CPUs is known when the possible map
is initialized, so the CPU numbers can be associated to the registered
non-present APIC IDs right there.

This allows to put more code into the __init section and makes the related
data __ro_after_init.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Tested-by: Sohil Mehta <sohil.mehta@intel.com>
Link: https://lore.kernel.org/r/20240213210252.517339971@linutronix.de

x86/cpu/topology: Reject unknown APIC IDs on ACPI hotplug

The topology bitmaps track all possible APIC IDs which have been registered
during enumeration. As sizing and further topology information is going to
be derived from these bitmaps, reject attempts to hotplug an APIC ID which
was not registered during enumeration.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Tested-by: Sohil Mehta <sohil.mehta@intel.com>
Link: https://lore.kernel.org/r/20240213210252.462231229@linutronix.de

x86/topology: Add a mechanism to track topology via APIC IDs

Topology on X86 is determined by the registered APIC IDs and the
segmentation information retrieved from CPUID. Depending on the granularity
of the provided CPUID information the most fine grained scheme looks like
this according to Intel terminology:

[PKG][DIEGRP][DIE][TILE][MODULE][CORE][THREAD]

Not enumerated domain levels consume 0 bits in the APIC ID. This allows to
provide a consistent view at the topology and determine other information
precisely like the number of cores in a package on hybrid systems, where
the existing assumption that number or cores == number of threads / threads
per core does not hold.

Provide per domain level bitmaps which record the APIC ID split into the
domain levels to make later evaluation of domain level specific information
simple. This allows to calculate e.g. the logical IDs without any further
extra logic.

Contrary to the existing registration mechanism this records disabled CPUs,
which are subject to later hotplug as well. That's useful for boot time
sizing of package or die dependent allocations without using heuristics.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Tested-by: Sohil Mehta <sohil.mehta@intel.com>
Link: https://lore.kernel.org/r/20240213210252.406985021@linutronix.de

x86/cpu: Detect real BSP on crash kernels

When a kdump kernel is started from a crashing CPU then there is no
guarantee that this CPU is the real boot CPU (BSP). If the kdump kernel
tries to online the BSP then the INIT sequence will reset the machine.

There is a command line option to prevent this, but in case of nested kdump
kernels this is wrong.

But that command line option is not required at all because the real
BSP is enumerated as the first CPU by firmware. Support for the only
known system which was different (Voyager) got removed long ago.

Detect whether the boot CPU APIC ID is the first APIC ID enumerated by
the firmware. If the first APIC ID enumerated is not matching the boot
CPU APIC ID then skip registering it.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Tested-by: Sohil Mehta <sohil.mehta@intel.com>
Link: https://lore.kernel.org/r/20240213210252.348542071@linutronix.de

x86/cpu/topology: Rework possible CPU management

Managing possible CPUs is an unreadable and uncomprehensible maze. Aside of
that it's backwards because it applies command line limits after
registering all APICs.

Rewrite it so that it:

- Applies the command line limits upfront so that only the allowed amount
of APIC IDs can be registered.

- Applies eventual late restrictions in an understandable way

- Uses simple min_t() calculations which are trivial to follow.

- Provides a separate function for resetting to UP mode late in the
bringup process.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Tested-by: Sohil Mehta <sohil.mehta@intel.com>
Link: https://lore.kernel.org/r/20240213210252.290098853@linutronix.de

x86/cpu/topology: Sanitize the APIC admission logic

Move the actually required content of generic_processor_id() into the call
sites and use common helper functions for them. This separates the early
boot registration and the ACPI hotplug mechanism completely which allows
further cleanups and improvements.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Tested-by: Sohil Mehta <sohil.mehta@intel.com>
Link: https://lore.kernel.org/r/20240213210252.230433953@linutronix.de

x86/cpu/topology: Use a data structure for topology info

Put the processor accounting into a data structure, which will gain more
topology related information in the next steps, and sanitize the accounting.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Tested-by: Sohil Mehta <sohil.mehta@intel.com>
Link: https://lore.kernel.org/r/20240213210252.111451909@linutronix.de

x86/cpu/topology: Simplify APIC registration

Having the same check whether the number of assigned CPUs has reached the
nr_cpu_ids limit twice in the same code path is pointless. Repeating the
information that CPUs are ignored over and over is also pointless noise.

Remove the redundant check and reduce the noise by using a pr_warn_once().

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Tested-by: Sohil Mehta <sohil.mehta@intel.com>
Link: https://lore.kernel.org/r/20240213210252.050264369@linutronix.de

x86/cpu/topology: Confine topology information

Now that all external fiddling with num_processors and disabled_cpus is
gone, move the last user prefill_possible_map() into the topology code too
and remove the global visibility of these variables.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Tested-by: Sohil Mehta <sohil.mehta@intel.com>
Link: https://lore.kernel.org/r/20240213210251.994756960@linutronix.de

x86/mpparse: Use new APIC registration function

Aside of switching over to the new interface, record the number of
registered CPUs locally, which allows to make num_processors and
disabled_cpus confined to the topology code.

No functional change intended.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Tested-by: Sohil Mehta <sohil.mehta@intel.com>
Link: https://lore.kernel.org/r/20240213210251.830955273@linutronix.de

x86/cpu/topology: Provide separate APIC registration functions

generic_processor_info() aside of being a complete misnomer is used for
both early boot registration and ACPI CPU hotplug.

While it's arguable that this can share some code, it results in code which
is hard to understand and kept around post init for no real reason.

Also the call sites do lots of manual fiddling in topology related
variables instead of having proper interfaces for the purpose which handle
the topology internals correctly.

Provide topology_register_apic(), topology_hotplug_apic() and
topology_hotunplug_apic() which have the extra magic of the call sites
incorporated and for now are wrappers around generic_processor_info().

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Tested-by: Sohil Mehta <sohil.mehta@intel.com>
Link: https://lore.kernel.org/r/20240213210251.605007456@linutronix.de

x86/cpu/topology: Move registration out of APIC code

The APIC/CPU registration sits in the middle of the APIC code. In fact this
is a topology evaluation function and has nothing to do with the inner
workings of the local APIC.

Move it out into a file which reflects what this is about.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Tested-by: Sohil Mehta <sohil.mehta@intel.com>
Link: https://lore.kernel.org/r/20240213210251.543948812@linutronix.de

x86/cpu: Remove topology.c

No more users. Stick it into the ugly code museum.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Juergen Gross <jgross@suse.com>
Tested-by: Sohil Mehta <sohil.mehta@intel.com>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Tested-by: Zhang Rui <rui.zhang@intel.com>
Tested-by: Wang Wendy <wendy.wang@intel.com>
Tested-by: K Prateek Nayak <kprateek.nayak@amd.com>
Link: https://lore.kernel.org/r/20240212153625.395230346@linutronix.de

x86/cpu: Use common topology code for Intel

Intel CPUs use either topology leaf 0xb/0x1f evaluation or the legacy
SMP/HT evaluation based on CPUID leaf 0x1/0x4.

Move it over to the consolidated topology code and remove the random
topology hacks which are sprinkled into the Intel and the common code.

No functional change intended.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Juergen Gross <jgross@suse.com>
Tested-by: Sohil Mehta <sohil.mehta@intel.com>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Tested-by: Zhang Rui <rui.zhang@intel.com>
Tested-by: Wang Wendy <wendy.wang@intel.com>
Tested-by: K Prateek Nayak <kprateek.nayak@amd.com>
Link: https://lore.kernel.org/r/20240212153624.893644349@linutronix.de

x86/cpu: Move __max_die_per_package to common.c

In preparation of a complete replacement for the topology leaf 0xb/0x1f
evaluation, move __max_die_per_package into the common code.

Will be removed once everything is converted over.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Juergen Gross <jgross@suse.com>
Tested-by: Sohil Mehta <sohil.mehta@intel.com>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Tested-by: Zhang Rui <rui.zhang@intel.com>
Tested-by: Wang Wendy <wendy.wang@intel.com>
Tested-by: K Prateek Nayak <kprateek.nayak@amd.com>
Link: https://lore.kernel.org/r/20240212153624.768188958@linutronix.de

x86/cpu: Move cpu_core_id into topology info

Rename it to core_id and stick it to the other ID fields.

No functional change.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Juergen Gross <jgross@suse.com>
Tested-by: Sohil Mehta <sohil.mehta@intel.com>
Tested-by: Michael Kelley <mikelley@microsoft.com>
Tested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Zhang Rui <rui.zhang@intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20230814085112.566519388@linutronix.de

x86/cpu: Move cpu_die_id into topology info

Move the next member.

No functional change.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Juergen Gross <jgross@suse.com>
Tested-by: Sohil Mehta <sohil.mehta@intel.com>
Tested-by: Michael Kelley <mikelley@microsoft.com>
Tested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Zhang Rui <rui.zhang@intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20230814085112.388185134@linutronix.de

x86/cpu: Move phys_proc_id into topology info

Rename it to pkg_id which is the terminology used in the kernel.

No functional change.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Juergen Gross <jgross@suse.com>
Tested-by: Sohil Mehta <sohil.mehta@intel.com>
Tested-by: Michael Kelley <mikelley@microsoft.com>
Tested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Zhang Rui <rui.zhang@intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20230814085112.329006989@linutronix.de

x86/cpu: Encapsulate topology information in cpuinfo_x86

The topology related information is randomly scattered across cpuinfo_x86.

Create a new structure cpuinfo_topo and move in a first step initial_apicid
and apicid into it.

Aside of being better readable this is in preparation for replacing the
horribly fragile CPU topology evaluation code further down the road.

Consolidate APIC ID fields to u32 as that represents the hardware type.

No functional change.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Juergen Gross <jgross@suse.com>
Tested-by: Sohil Mehta <sohil.mehta@intel.com>
Tested-by: Michael Kelley <mikelley@microsoft.com>
Tested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Zhang Rui <rui.zhang@intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20230814085112.269787744@linutronix.de

x86/topology: Fix erroneous smp_num_siblings on Intel Hybrid platforms

Traditionally, all CPUs in a system have identical numbers of SMT
siblings. That changes with hybrid processors where some logical CPUs
have a sibling and others have none.

Today, the CPU boot code sets the global variable smp_num_siblings when
every CPU thread is brought up. The last thread to boot will overwrite
it with the number of siblings of *that* thread. That last thread to
boot will "win". If the thread is a Pcore, smp_num_siblings == 2. If it
is an Ecore, smp_num_siblings == 1.

smp_num_siblings describes if the *system* supports SMT. It should
specify the maximum number of SMT threads among all cores.

Ensure that smp_num_siblings represents the system-wide maximum number
of siblings by always increasing its value. Never allow it to decrease.

On MeteorLake-P platform, this fixes a problem that the Ecore CPUs are
not updated in any cpu sibling map because the system is treated as an
UP system when probing Ecore CPUs.

Below shows part of the CPU topology information before and after the
fix, for both Pcore and Ecore CPU (cpu0 is Pcore, cpu 12 is Ecore).
...
-/sys/devices/system/cpu/cpu0/topology/package_cpus:000fff
-/sys/devices/system/cpu/cpu0/topology/package_cpus_list:0-11
+/sys/devices/system/cpu/cpu0/topology/package_cpus:3fffff
+/sys/devices/system/cpu/cpu0/topology/package_cpus_list:0-21
...
-/sys/devices/system/cpu/cpu12/topology/package_cpus:001000
-/sys/devices/system/cpu/cpu12/topology/package_cpus_list:12
+/sys/devices/system/cpu/cpu12/topology/package_cpus:3fffff
+/sys/devices/system/cpu/cpu12/topology/package_cpus_list:0-21

Notice that the "before" 'package_cpus_list' has only one CPU. This
means that userspace tools like lscpu will see a little laptop like
an 11-socket system:

-Core(s) per socket: 1
-Socket(s): 11
+Core(s) per socket: 16
+Socket(s): 1

This is also expected to make the scheduler do rather wonky things
too.

[ dhansen: remove CPUID detail from changelog, add end user effects ]

CC: stable@kernel.org
Fixes: bbb65d2d365e ("x86: use cpuid vector 0xb when available for detecting cpu topology")
Fixes: 95f3d39ccf7a ("x86/cpu/topology: Provide detect_extended_topology_early()")
Suggested-by: Len Brown <len.brown@intel.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/all/20230323015640.27906-1-rui.zhang%40intel.com

x86/topology: Fix duplicated core ID within a package

Today, core ID is assumed to be unique within each package.

But an AlderLake-N platform adds a Module level between core and package,
Linux excludes the unknown modules bits from the core ID, resulting in
duplicate core ID's.

To keep core ID unique within a package, Linux must include all APIC-ID
bits for known or unknown levels above the core and below the package
in the core ID.

It is important to understand that core ID's have always come directly
from the APIC-ID encoding, which comes from the BIOS. Thus there is no
guarantee that they start at 0, or that they are contiguous.
As such, naively using them for array indexes can be problematic.

[ dhansen: un-known -> unknown ]

Fixes: 7745f03eb395 ("x86/topology: Add CPUID.1F multi-die/package support")
Suggested-by: Len Brown <len.brown@intel.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Len Brown <len.brown@intel.com>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20221014090147.1836-5-rui.zhang@intel.com

x86/topology: Fix multiple packages shown on a single-package system

CPUID.1F/B does not enumerate Package level explicitly, instead, all the
APIC-ID bits above the enumerated levels are assumed to be package ID
bits.

Current code gets package ID by shifting out all the APIC-ID bits that
Linux supports, rather than shifting out all the APIC-ID bits that
CPUID.1F enumerates. This introduces problems when CPUID.1F enumerates a
level that Linux does not support.

For example, on a single package AlderLake-N, there are 2 Ecore Modules
with 4 atom cores in each module. Linux does not support the Module
level and interprets the Module ID bits as package ID and erroneously
reports a multi module system as a multi-package system.

Fix this by using APIC-ID bits above all the CPUID.1F enumerated levels
as package ID.

[ dhansen: spelling fix ]

Fixes: 7745f03eb395 ("x86/topology: Add CPUID.1F multi-die/package support")
Suggested-by: Len Brown <len.brown@intel.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Len Brown <len.brown@intel.com>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20221014090147.1836-4-rui.zhang@intel.com

x86: Fix various typos in comments

Fix ~144 single-word typos in arch/x86/ code comments.

Doing this in a single commit should reduce the churn.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: linux-kernel@vger.kernel.org

x86/topology: Make __max_die_per_package available unconditionally

Move it outside of CONFIG_SMP in order to avoid ifdeffery at the usage
sites.

Fixes: 76e2fc63ca40 ("x86/cpu/amd: Set __max_die_per_package on AMD")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20210114111814.5346-1-bp@alien8.de

x86/topology: Set cpu_die_id only if DIE_TYPE found

CPUID Leaf 0x1F defines a DIE_TYPE level (nb: ECX[8:15] level type == 0x5),
but CPUID Leaf 0xB does not. However, detect_extended_topology() will
set struct cpuinfo_x86.cpu_die_id regardless of whether a valid Die ID
was found.

Only set cpu_die_id if a DIE_TYPE level is found. CPU topology code may
use another value for cpu_die_id, e.g. the AMD NodeId on AMD-based
systems. Code ordering should be maintained so that the CPUID Leaf 0x1F
Die ID value will take precedence on systems that may use another value.

Suggested-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20201109210659.754018-5-Yazen.Ghannam@amd.com

x86/mm/pat: Rename <asm/pat.h> => <asm/memtype.h>

pat.h is a file whose main purpose is to provide the memtype_*() APIs.

PAT is the low level hardware mechanism - but the high level abstraction
is memtype.

So name the header <memtype.h> as well - this goes hand in hand with memtype.c
and memtype_interval.c.

Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/topology: Create topology_max_die_per_package()

topology_max_packages() is available to size resources to cover all
packages in the system.

But now multi-die/package systems are coming up, and some resources are
per-die.

Create topology_max_die_per_package(), for detecting multi-die/package
systems, and sizing any per-die resources.

Signed-off-by: Len Brown <len.brown@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/e6eaf384571ae52ac7d0ca41510b7fb7d2fda0e4.1557769318.git.len.brown@intel.com

x86/topology: Add CPUID.1F multi-die/package support

Some new systems have multiple software-visible die within each package.

Update Linux parsing of the Intel CPUID "Extended Topology Leaf" to handle
either CPUID.B, or the new CPUID.1F.

Add cpuinfo_x86.die_id and cpuinfo_x86.max_dies to store the result.

die_id will be non-zero only for multi-die/package systems.

Signed-off-by: Len Brown <len.brown@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: linux-doc@vger.kernel.org
Link: https://lkml.kernel.org/r/7b23d2d26d717b8e14ba137c94b70943f1ae4b5c.1557769318.git.len.brown@intel.com

x86/kernel: Fix more -Wmissing-prototypes warnings

... with the goal of eventually enabling -Wmissing-prototypes by
default. At least on x86.

Make functions static where possible, otherwise add prototypes or make
them visible through includes.

asm/trace/ changes courtesy of Steven Rostedt <rostedt@goodmis.org>.

Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> # ACPI + cpufreq bits
Cc: Andrew Banman <andrew.banman@hpe.com>
Cc: Dimitri Sivanich <dimitri.sivanich@hpe.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mike Travis <mike.travis@hpe.com>
Cc: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Yi Wang <wang.yi59@zte.com.cn>
Cc: linux-acpi@vger.kernel.org

x86/cpu/topology: Provide detect_extended_topology_early()

To support force disabling of SMT it's required to know the number of
thread siblings early. detect_extended_topology() cannot be called before
the APIC driver is selected, so split out the part which initializes
smp_num_siblings.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Ingo Molnar <mingo@kernel.org>

x86/cpu: Remove the pointless CPU printout

The value of this printout is dubious at best and there is no point in
having it in two different places along with convoluted ways to reach it.

Remove it completely.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Ingo Molnar <mingo@kernel.org>

x86/CPU: Modify detect_extended_topology() to return result

Current implementation does not communicate whether it can successfully
detect CPUID function 0xB information. Therefore, modify the function to
return success or error codes. This will be used by subsequent patches.

Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/1524865681-112110-2-git-send-email-suravee.suthikulpanit@amd.com

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.

For non */uapi/* files that summary was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139

and resulted in the first patch in this series.

If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930

and resulted in the second patch in this series.

- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:

SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1

and that resulted in the third patch in this series.

- when the two scanners agreed on the detected license(s), that became
the concluded license(s).

- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.

- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).

- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.

- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct

This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

x86/cpu: Convert printk(KERN_<LEVEL> ...) to pr_<level>(...)

- Use the more current logging style pr_<level>(...) instead of the old
printk(KERN_<LEVEL> ...).

- Convert pr_warning() to pr_warn().

Signed-off-by: Chen Yucong <slaoub@gmail.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1454384702-21707-1-git-send-email-slaoub@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86: delete __cpuinit usage from all x86 files

The __cpuinit type of throwaway sections might have made sense
some time ago when RAM was more constrained, but now the savings
do not offset the cost and complications. For example, the fix in
commit 5e427ec2d0 ("x86: Fix bit corruption at CPU resume time")
is a good example of the nasty type of bugs that can be created
with improper use of the various __init prefixes.

After a discussion on LKML[1] it was decided that cpuinit should go
the way of devinit and be phased out. Once all the users are gone,
we can then finally remove the macros themselves from linux/init.h.

Note that some harmless section mismatch warnings may result, since
notify_cpu_starting() and cpu_up() are arch independent (kernel/cpu.c)
are flagged as __cpuinit -- so if we remove the __cpuinit from
arch specific callers, we will also get section mismatch warnings.
As an intermediate step, we intend to turn the linux/init.h cpuinit
content into no-ops as early as possible, since that will get rid
of these warnings. In any case, they are temporary and harmless.

This removes all the arch/x86 uses of the __cpuinit macros from
all C files. x86 only had the one __CPUINIT used in assembly files,
and it wasn't paired off with a .previous or a __FINIT, so we can
delete it directly w/o any corresponding additional change there.

[1] https://lkml.org/lkml/2013/5/20/589

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: x86@kernel.org
Acked-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: H. Peter Anvin <hpa@linux.intel.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

x86, cpu: Split addon_cpuid_features.c

addon_cpuid_features.c contains exactly two almost completely
unrelated functions, plus has a long and very generic name. Split it
into two files, scattered.c for the scattered feature flags, and
topology.c for the topology information.

Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
LKML-Reference: <tip-*@git.kernel.org>