linux.git/arch/x86/kernel/cpu/cacheinfo.c, branch v6.8

x86/cpu: Move cpu_l[l2]c_id into topology info

2023-10-10T12:38:18+00:00

The topology IDs which identify the LLC and L2 domains clearly belong to
the per CPU topology information.

Move them into cpuinfo_x86::cpuinfo_topo and get rid of the extra per CPU
data and the related exports.

This also paves the way to do proper topology evaluation during early boot
because it removes the only per CPU dependency for that.

No functional change.

Signed-off-by: Thomas Gleixner 
Tested-by: Juergen Gross 
Tested-by: Sohil Mehta 
Tested-by: Michael Kelley 
Tested-by: Peter Zijlstra (Intel) 
Tested-by: Zhang Rui 
Reviewed-by: Arjan van de Ven 
Acked-by: Peter Zijlstra (Intel) 
Link: https://lore.kernel.org/r/20230814085112.803864641@linutronix.de

x86/cpu: Move cpu_die_id into topology info

2023-10-10T12:38:17+00:00

Move the next member.

No functional change.

Signed-off-by: Thomas Gleixner 
Tested-by: Juergen Gross 
Tested-by: Sohil Mehta 
Tested-by: Michael Kelley 
Tested-by: Peter Zijlstra (Intel) 
Tested-by: Zhang Rui 
Acked-by: Peter Zijlstra (Intel) 
Link: https://lore.kernel.org/r/20230814085112.388185134@linutronix.de

x86/cpu: Move phys_proc_id into topology info

2023-10-10T12:38:17+00:00

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

No functional change.

Signed-off-by: Thomas Gleixner 
Tested-by: Juergen Gross 
Tested-by: Sohil Mehta 
Tested-by: Michael Kelley 
Tested-by: Peter Zijlstra (Intel) 
Tested-by: Zhang Rui 
Acked-by: Peter Zijlstra (Intel) 
Link: https://lore.kernel.org/r/20230814085112.329006989@linutronix.de

x86/cpu: Encapsulate topology information in cpuinfo_x86

2023-10-10T12:38:17+00:00

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 
Tested-by: Juergen Gross 
Tested-by: Sohil Mehta 
Tested-by: Michael Kelley 
Tested-by: Peter Zijlstra (Intel) 
Tested-by: Zhang Rui 
Acked-by: Peter Zijlstra (Intel) 
Link: https://lore.kernel.org/r/20230814085112.269787744@linutronix.de

x86/cpu/cacheinfo: Remove cpu_callout_mask dependency

2023-05-15T11:44:52+00:00

cpu_callout_mask is used for the stop machine based MTRR/PAT init.

In preparation of moving the BP/AP synchronization to the core hotplug
code, use a private CPU mask for cacheinfo and manage it in the
starting/dying hotplug state.

Signed-off-by: Thomas Gleixner 
Signed-off-by: Peter Zijlstra (Intel) 
Tested-by: Michael Kelley 
Tested-by: Oleksandr Natalenko 
Tested-by: Helge Deller  # parisc
Tested-by: Guilherme G. Piccoli  # Steam Deck
Link: https://lore.kernel.org/r/20230512205256.035041005@linutronix.de

x86/cacheinfo: Remove unused trace variable

2023-02-11T09:43:31+00:00

15cd8812ab2c ("x86: Remove the CPU cache size printk's") removed the
last use of the trace local var. Remove it too and the useless trace
cache case.

No functional changes.

Reported-by: Jiapeng Chong 
Signed-off-by: Borislav Petkov (AMD) 
Link: https://lore.kernel.org/r/20230210234541.9694-1-bp@alien8.de
Link: http://lore.kernel.org/r/20220705073349.1512-1-jiapeng.chong@linux.alibaba.com

x86/cacheinfo: Switch cache_ap_init() to hotplug callback

2022-11-10T12:12:45+00:00

Instead of explicitly calling cache_ap_init() in
identify_secondary_cpu() use a CPU hotplug callback instead. By
registering the callback only after having started the non-boot CPUs
and initializing cache_aps_delayed_init with "true", calling
set_cache_aps_delayed_init() at boot time can be dropped.

It should be noted that this change results in cache_ap_init() being
called a little bit later when hotplugging CPUs. By using a new
hotplug slot right at the start of the low level bringup this is not
problematic, as no operations requiring a specific caching mode are
performed that early in CPU initialization.

Suggested-by: Borislav Petkov 
Signed-off-by: Juergen Gross 
Signed-off-by: Borislav Petkov 
Link: https://lore.kernel.org/r/20221102074713.21493-15-jgross@suse.com
Signed-off-by: Borislav Petkov

x86: Decouple PAT and MTRR handling

2022-11-10T12:12:45+00:00

Today, PAT is usable only with MTRR being active, with some nasty tweaks
to make PAT usable when running as a Xen PV guest which doesn't support
MTRR.

The reason for this coupling is that both PAT MSR changes and MTRR
changes require a similar sequence and so full PAT support was added
using the already available MTRR handling.

Xen PV PAT handling can work without MTRR, as it just needs to consume
the PAT MSR setting done by the hypervisor without the ability and need
to change it. This in turn has resulted in a convoluted initialization
sequence and wrong decisions regarding cache mode availability due to
misguiding PAT availability flags.

Fix all of that by allowing to use PAT without MTRR and by reworking
the current PAT initialization sequence to match better with the newly
introduced generic cache initialization.

This removes the need of the recently added pat_force_disabled flag, so
remove the remnants of the patch adding it.

Signed-off-by: Juergen Gross 
Signed-off-by: Borislav Petkov 
Link: https://lore.kernel.org/r/20221102074713.21493-14-jgross@suse.com
Signed-off-by: Borislav Petkov

x86/mtrr: Add a stop_machine() handler calling only cache_cpu_init()

2022-11-10T12:12:45+00:00

Instead of having a stop_machine() handler for either a specific
MTRR register or all state at once, add a handler just for calling
cache_cpu_init() if appropriate.

Add functions for calling stop_machine() with this handler as well.

Add a generic replacement for mtrr_bp_restore() and a wrapper for
mtrr_bp_init().

Signed-off-by: Juergen Gross 
Signed-off-by: Borislav Petkov 
Link: https://lore.kernel.org/r/20221102074713.21493-13-jgross@suse.com
Signed-off-by: Borislav Petkov

x86/mtrr: Let cache_aps_delayed_init replace mtrr_aps_delayed_init

2022-11-10T12:12:45+00:00

In order to prepare decoupling MTRR and PAT replace the MTRR-specific
mtrr_aps_delayed_init flag with a more generic cache_aps_delayed_init
one.

Signed-off-by: Juergen Gross 
Signed-off-by: Borislav Petkov 
Link: https://lore.kernel.org/r/20221102074713.21493-12-jgross@suse.com
Signed-off-by: Borislav Petkov