<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/arch/x86/kernel/cpu/amd.c, branch v6.9</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>x86/CPU/AMD: Add models 0x10-0x1f to the Zen5 range</title>
<updated>2024-04-24T12:05:25+00:00</updated>
<author>
<name>Wenkuan Wang</name>
<email>Wenkuan.Wang@amd.com</email>
</author>
<published>2024-04-10T03:53:08+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=2718a7fdf292b2dcb49c856fa8a6a955ebbbc45f'/>
<id>2718a7fdf292b2dcb49c856fa8a6a955ebbbc45f</id>
<content type='text'>
Add some more Zen5 models.

Fixes: 3e4147f33f8b ("x86/CPU/AMD: Add X86_FEATURE_ZEN5")
Signed-off-by: Wenkuan Wang &lt;Wenkuan.Wang@amd.com&gt;
Signed-off-by: Borislav Petkov (AMD) &lt;bp@alien8.de&gt;
Link: https://lore.kernel.org/r/20240423144111.1362-1-bp@kernel.org
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Add some more Zen5 models.

Fixes: 3e4147f33f8b ("x86/CPU/AMD: Add X86_FEATURE_ZEN5")
Signed-off-by: Wenkuan Wang &lt;Wenkuan.Wang@amd.com&gt;
Signed-off-by: Borislav Petkov (AMD) &lt;bp@alien8.de&gt;
Link: https://lore.kernel.org/r/20240423144111.1362-1-bp@kernel.org
</pre>
</div>
</content>
</entry>
<entry>
<title>x86/cpu/amd: Move TOPOEXT enablement into the topology parser</title>
<updated>2024-04-12T10:05:54+00:00</updated>
<author>
<name>Thomas Gleixner</name>
<email>tglx@linutronix.de</email>
</author>
<published>2024-04-11T16:55:38+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=7211274fe0ee352332255e41ab5e628b86e83994'/>
<id>7211274fe0ee352332255e41ab5e628b86e83994</id>
<content type='text'>
The topology rework missed that early_init_amd() tries to re-enable the
Topology Extensions when the BIOS disabled them.

The new parser is invoked before early_init_amd() so the re-enable attempt
happens too late.

Move it into the AMD specific topology parser code where it belongs.

Fixes: f7fb3b2dd92c ("x86/cpu: Provide an AMD/HYGON specific topology parser")
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
Link: https://lore.kernel.org/r/878r1j260l.ffs@tglx
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The topology rework missed that early_init_amd() tries to re-enable the
Topology Extensions when the BIOS disabled them.

The new parser is invoked before early_init_amd() so the re-enable attempt
happens too late.

Move it into the AMD specific topology parser code where it belongs.

Fixes: f7fb3b2dd92c ("x86/cpu: Provide an AMD/HYGON specific topology parser")
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
Link: https://lore.kernel.org/r/878r1j260l.ffs@tglx
</pre>
</div>
</content>
</entry>
<entry>
<title>x86/CPU/AMD: Track SNP host status with cc_platform_*()</title>
<updated>2024-04-04T08:40:30+00:00</updated>
<author>
<name>Borislav Petkov (AMD)</name>
<email>bp@alien8.de</email>
</author>
<published>2024-03-27T15:43:17+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=0ecaefb303de69929dc0036d5021d01cec7ea052'/>
<id>0ecaefb303de69929dc0036d5021d01cec7ea052</id>
<content type='text'>
The host SNP worthiness can determined later, after alternatives have
been patched, in snp_rmptable_init() depending on cmdline options like
iommu=pt which is incompatible with SNP, for example.

Which means that one cannot use X86_FEATURE_SEV_SNP and will need to
have a special flag for that control.

Use that newly added CC_ATTR_HOST_SEV_SNP in the appropriate places.

Move kdump_sev_callback() to its rightful place, while at it.

Fixes: 216d106c7ff7 ("x86/sev: Add SEV-SNP host initialization support")
Signed-off-by: Borislav Petkov (AMD) &lt;bp@alien8.de&gt;
Reviewed-by: Tom Lendacky &lt;thomas.lendacky@amd.com&gt;
Tested-by: Srikanth Aithal &lt;sraithal@amd.com&gt;
Link: https://lore.kernel.org/r/20240327154317.29909-6-bp@alien8.de
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The host SNP worthiness can determined later, after alternatives have
been patched, in snp_rmptable_init() depending on cmdline options like
iommu=pt which is incompatible with SNP, for example.

Which means that one cannot use X86_FEATURE_SEV_SNP and will need to
have a special flag for that control.

Use that newly added CC_ATTR_HOST_SEV_SNP in the appropriate places.

Move kdump_sev_callback() to its rightful place, while at it.

Fixes: 216d106c7ff7 ("x86/sev: Add SEV-SNP host initialization support")
Signed-off-by: Borislav Petkov (AMD) &lt;bp@alien8.de&gt;
Reviewed-by: Tom Lendacky &lt;thomas.lendacky@amd.com&gt;
Tested-by: Srikanth Aithal &lt;sraithal@amd.com&gt;
Link: https://lore.kernel.org/r/20240327154317.29909-6-bp@alien8.de
</pre>
</div>
</content>
</entry>
<entry>
<title>x86/CPU/AMD: Update the Zenbleed microcode revisions</title>
<updated>2024-03-16T16:04:09+00:00</updated>
<author>
<name>Borislav Petkov (AMD)</name>
<email>bp@alien8.de</email>
</author>
<published>2024-03-15T21:42:27+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=5c84b051bd4e777cf37aaff983277e58c99618d5'/>
<id>5c84b051bd4e777cf37aaff983277e58c99618d5</id>
<content type='text'>
Update them to the correct revision numbers.

Fixes: 522b1d69219d ("x86/cpu/amd: Add a Zenbleed fix")
Signed-off-by: Borislav Petkov (AMD) &lt;bp@alien8.de&gt;
Cc: &lt;stable@kernel.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Update them to the correct revision numbers.

Fixes: 522b1d69219d ("x86/cpu/amd: Add a Zenbleed fix")
Signed-off-by: Borislav Petkov (AMD) &lt;bp@alien8.de&gt;
Cc: &lt;stable@kernel.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'x86-core-2024-03-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip</title>
<updated>2024-03-12T02:53:15+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2024-03-12T02:53:15+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=685d98211273f60e38a6d361b62d7016c545297e'/>
<id>685d98211273f60e38a6d361b62d7016c545297e</id>
<content type='text'>
Pull core x86 updates from Ingo Molnar:

 - The biggest change is the rework of the percpu code, to support the
   'Named Address Spaces' GCC feature, by Uros Bizjak:

      - This allows C code to access GS and FS segment relative memory
        via variables declared with such attributes, which allows the
        compiler to better optimize those accesses than the previous
        inline assembly code.

      - The series also includes a number of micro-optimizations for
        various percpu access methods, plus a number of cleanups of %gs
        accesses in assembly code.

      - These changes have been exposed to linux-next testing for the
        last ~5 months, with no known regressions in this area.

 - Fix/clean up __switch_to()'s broken but accidentally working handling
   of FPU switching - which also generates better code

 - Propagate more RIP-relative addressing in assembly code, to generate
   slightly better code

 - Rework the CPU mitigations Kconfig space to be less idiosyncratic, to
   make it easier for distros to follow &amp; maintain these options

 - Rework the x86 idle code to cure RCU violations and to clean up the
   logic

 - Clean up the vDSO Makefile logic

 - Misc cleanups and fixes

* tag 'x86-core-2024-03-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (52 commits)
  x86/idle: Select idle routine only once
  x86/idle: Let prefer_mwait_c1_over_halt() return bool
  x86/idle: Cleanup idle_setup()
  x86/idle: Clean up idle selection
  x86/idle: Sanitize X86_BUG_AMD_E400 handling
  sched/idle: Conditionally handle tick broadcast in default_idle_call()
  x86: Increase brk randomness entropy for 64-bit systems
  x86/vdso: Move vDSO to mmap region
  x86/vdso/kbuild: Group non-standard build attributes and primary object file rules together
  x86/vdso: Fix rethunk patching for vdso-image-{32,64}.o
  x86/retpoline: Ensure default return thunk isn't used at runtime
  x86/vdso: Use CONFIG_COMPAT_32 to specify vdso32
  x86/vdso: Use $(addprefix ) instead of $(foreach )
  x86/vdso: Simplify obj-y addition
  x86/vdso: Consolidate targets and clean-files
  x86/bugs: Rename CONFIG_RETHUNK              =&gt; CONFIG_MITIGATION_RETHUNK
  x86/bugs: Rename CONFIG_CPU_SRSO             =&gt; CONFIG_MITIGATION_SRSO
  x86/bugs: Rename CONFIG_CPU_IBRS_ENTRY       =&gt; CONFIG_MITIGATION_IBRS_ENTRY
  x86/bugs: Rename CONFIG_CPU_UNRET_ENTRY      =&gt; CONFIG_MITIGATION_UNRET_ENTRY
  x86/bugs: Rename CONFIG_SLS                  =&gt; CONFIG_MITIGATION_SLS
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull core x86 updates from Ingo Molnar:

 - The biggest change is the rework of the percpu code, to support the
   'Named Address Spaces' GCC feature, by Uros Bizjak:

      - This allows C code to access GS and FS segment relative memory
        via variables declared with such attributes, which allows the
        compiler to better optimize those accesses than the previous
        inline assembly code.

      - The series also includes a number of micro-optimizations for
        various percpu access methods, plus a number of cleanups of %gs
        accesses in assembly code.

      - These changes have been exposed to linux-next testing for the
        last ~5 months, with no known regressions in this area.

 - Fix/clean up __switch_to()'s broken but accidentally working handling
   of FPU switching - which also generates better code

 - Propagate more RIP-relative addressing in assembly code, to generate
   slightly better code

 - Rework the CPU mitigations Kconfig space to be less idiosyncratic, to
   make it easier for distros to follow &amp; maintain these options

 - Rework the x86 idle code to cure RCU violations and to clean up the
   logic

 - Clean up the vDSO Makefile logic

 - Misc cleanups and fixes

* tag 'x86-core-2024-03-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (52 commits)
  x86/idle: Select idle routine only once
  x86/idle: Let prefer_mwait_c1_over_halt() return bool
  x86/idle: Cleanup idle_setup()
  x86/idle: Clean up idle selection
  x86/idle: Sanitize X86_BUG_AMD_E400 handling
  sched/idle: Conditionally handle tick broadcast in default_idle_call()
  x86: Increase brk randomness entropy for 64-bit systems
  x86/vdso: Move vDSO to mmap region
  x86/vdso/kbuild: Group non-standard build attributes and primary object file rules together
  x86/vdso: Fix rethunk patching for vdso-image-{32,64}.o
  x86/retpoline: Ensure default return thunk isn't used at runtime
  x86/vdso: Use CONFIG_COMPAT_32 to specify vdso32
  x86/vdso: Use $(addprefix ) instead of $(foreach )
  x86/vdso: Simplify obj-y addition
  x86/vdso: Consolidate targets and clean-files
  x86/bugs: Rename CONFIG_RETHUNK              =&gt; CONFIG_MITIGATION_RETHUNK
  x86/bugs: Rename CONFIG_CPU_SRSO             =&gt; CONFIG_MITIGATION_SRSO
  x86/bugs: Rename CONFIG_CPU_IBRS_ENTRY       =&gt; CONFIG_MITIGATION_IBRS_ENTRY
  x86/bugs: Rename CONFIG_CPU_UNRET_ENTRY      =&gt; CONFIG_MITIGATION_UNRET_ENTRY
  x86/bugs: Rename CONFIG_SLS                  =&gt; CONFIG_MITIGATION_SLS
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'x86_sev_for_v6.9_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip</title>
<updated>2024-03-12T00:44:11+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2024-03-12T00:44:11+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=38b334fc767e44816be087b3ec5d84b1438b735f'/>
<id>38b334fc767e44816be087b3ec5d84b1438b735f</id>
<content type='text'>
Pull x86 SEV updates from Borislav Petkov:

 - Add the x86 part of the SEV-SNP host support.

   This will allow the kernel to be used as a KVM hypervisor capable of
   running SNP (Secure Nested Paging) guests. Roughly speaking, SEV-SNP
   is the ultimate goal of the AMD confidential computing side,
   providing the most comprehensive confidential computing environment
   up to date.

   This is the x86 part and there is a KVM part which did not get ready
   in time for the merge window so latter will be forthcoming in the
   next cycle.

 - Rework the early code's position-dependent SEV variable references in
   order to allow building the kernel with clang and -fPIE/-fPIC and
   -mcmodel=kernel

 - The usual set of fixes, cleanups and improvements all over the place

* tag 'x86_sev_for_v6.9_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (36 commits)
  x86/sev: Disable KMSAN for memory encryption TUs
  x86/sev: Dump SEV_STATUS
  crypto: ccp - Have it depend on AMD_IOMMU
  iommu/amd: Fix failure return from snp_lookup_rmpentry()
  x86/sev: Fix position dependent variable references in startup code
  crypto: ccp: Make snp_range_list static
  x86/Kconfig: Remove CONFIG_AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
  Documentation: virt: Fix up pre-formatted text block for SEV ioctls
  crypto: ccp: Add the SNP_SET_CONFIG command
  crypto: ccp: Add the SNP_COMMIT command
  crypto: ccp: Add the SNP_PLATFORM_STATUS command
  x86/cpufeatures: Enable/unmask SEV-SNP CPU feature
  KVM: SEV: Make AVIC backing, VMSA and VMCB memory allocation SNP safe
  crypto: ccp: Add panic notifier for SEV/SNP firmware shutdown on kdump
  iommu/amd: Clean up RMP entries for IOMMU pages during SNP shutdown
  crypto: ccp: Handle legacy SEV commands when SNP is enabled
  crypto: ccp: Handle non-volatile INIT_EX data when SNP is enabled
  crypto: ccp: Handle the legacy TMR allocation when SNP is enabled
  x86/sev: Introduce an SNP leaked pages list
  crypto: ccp: Provide an API to issue SEV and SNP commands
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull x86 SEV updates from Borislav Petkov:

 - Add the x86 part of the SEV-SNP host support.

   This will allow the kernel to be used as a KVM hypervisor capable of
   running SNP (Secure Nested Paging) guests. Roughly speaking, SEV-SNP
   is the ultimate goal of the AMD confidential computing side,
   providing the most comprehensive confidential computing environment
   up to date.

   This is the x86 part and there is a KVM part which did not get ready
   in time for the merge window so latter will be forthcoming in the
   next cycle.

 - Rework the early code's position-dependent SEV variable references in
   order to allow building the kernel with clang and -fPIE/-fPIC and
   -mcmodel=kernel

 - The usual set of fixes, cleanups and improvements all over the place

* tag 'x86_sev_for_v6.9_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (36 commits)
  x86/sev: Disable KMSAN for memory encryption TUs
  x86/sev: Dump SEV_STATUS
  crypto: ccp - Have it depend on AMD_IOMMU
  iommu/amd: Fix failure return from snp_lookup_rmpentry()
  x86/sev: Fix position dependent variable references in startup code
  crypto: ccp: Make snp_range_list static
  x86/Kconfig: Remove CONFIG_AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
  Documentation: virt: Fix up pre-formatted text block for SEV ioctls
  crypto: ccp: Add the SNP_SET_CONFIG command
  crypto: ccp: Add the SNP_COMMIT command
  crypto: ccp: Add the SNP_PLATFORM_STATUS command
  x86/cpufeatures: Enable/unmask SEV-SNP CPU feature
  KVM: SEV: Make AVIC backing, VMSA and VMCB memory allocation SNP safe
  crypto: ccp: Add panic notifier for SEV/SNP firmware shutdown on kdump
  iommu/amd: Clean up RMP entries for IOMMU pages during SNP shutdown
  crypto: ccp: Handle legacy SEV commands when SNP is enabled
  crypto: ccp: Handle non-volatile INIT_EX data when SNP is enabled
  crypto: ccp: Handle the legacy TMR allocation when SNP is enabled
  x86/sev: Introduce an SNP leaked pages list
  crypto: ccp: Provide an API to issue SEV and SNP commands
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'x86_cpu_for_v6.9_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip</title>
<updated>2024-03-12T00:25:45+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2024-03-12T00:25:45+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=742582acec1e894b80815ab379e1c9d347a0406b'/>
<id>742582acec1e894b80815ab379e1c9d347a0406b</id>
<content type='text'>
Pull x86 cpu update from Borislav Petkov:

 - Have AMD Zen common init code run on all families from Zen1 onwards
   in order to save some future enablement effort

* tag 'x86_cpu_for_v6.9_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/CPU/AMD: Do the common init on future Zens too
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull x86 cpu update from Borislav Petkov:

 - Have AMD Zen common init code run on all families from Zen1 onwards
   in order to save some future enablement effort

* tag 'x86_cpu_for_v6.9_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/CPU/AMD: Do the common init on future Zens too
</pre>
</div>
</content>
</entry>
<entry>
<title>x86/CPU/AMD: Do the common init on future Zens too</title>
<updated>2024-02-16T12:15:12+00:00</updated>
<author>
<name>Borislav Petkov (AMD)</name>
<email>bp@alien8.de</email>
</author>
<published>2024-02-01T16:10:24+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=03ceaf678d444e67fb9c1a372458ba869aa37a60'/>
<id>03ceaf678d444e67fb9c1a372458ba869aa37a60</id>
<content type='text'>
There's no need to enable the common Zen init stuff for each new family
- just do it by default on everything &gt;= 0x17 family.

Signed-off-by: Borislav Petkov (AMD) &lt;bp@alien8.de&gt;
Reviewed-by: Tom Lendacky &lt;thomas.lendacky@amd.com&gt;
Link: https://lore.kernel.org/r/20240201161024.30839-1-bp@alien8.de
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
There's no need to enable the common Zen init stuff for each new family
- just do it by default on everything &gt;= 0x17 family.

Signed-off-by: Borislav Petkov (AMD) &lt;bp@alien8.de&gt;
Reviewed-by: Tom Lendacky &lt;thomas.lendacky@amd.com&gt;
Link: https://lore.kernel.org/r/20240201161024.30839-1-bp@alien8.de
</pre>
</div>
</content>
</entry>
<entry>
<title>x86/cpu: Use common topology code for AMD</title>
<updated>2024-02-15T21:07:38+00:00</updated>
<author>
<name>Thomas Gleixner</name>
<email>tglx@linutronix.de</email>
</author>
<published>2024-02-13T21:04:14+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=c749ce393b8fe9db5ed894411f06eafa88f0e13a'/>
<id>c749ce393b8fe9db5ed894411f06eafa88f0e13a</id>
<content type='text'>
Switch it over to the new topology evaluation mechanism and remove the
random bits and pieces which are sprinkled all over the place.

No functional change intended.

Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Tested-by: Juergen Gross &lt;jgross@suse.com&gt;
Tested-by: Sohil Mehta &lt;sohil.mehta@intel.com&gt;
Tested-by: Michael Kelley &lt;mhklinux@outlook.com&gt;
Tested-by: Zhang Rui &lt;rui.zhang@intel.com&gt;
Tested-by: Wang Wendy &lt;wendy.wang@intel.com&gt;
Tested-by: K Prateek Nayak &lt;kprateek.nayak@amd.com&gt;
Link: https://lore.kernel.org/r/20240212153625.145745053@linutronix.de

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Switch it over to the new topology evaluation mechanism and remove the
random bits and pieces which are sprinkled all over the place.

No functional change intended.

Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Tested-by: Juergen Gross &lt;jgross@suse.com&gt;
Tested-by: Sohil Mehta &lt;sohil.mehta@intel.com&gt;
Tested-by: Michael Kelley &lt;mhklinux@outlook.com&gt;
Tested-by: Zhang Rui &lt;rui.zhang@intel.com&gt;
Tested-by: Wang Wendy &lt;wendy.wang@intel.com&gt;
Tested-by: K Prateek Nayak &lt;kprateek.nayak@amd.com&gt;
Link: https://lore.kernel.org/r/20240212153625.145745053@linutronix.de

</pre>
</div>
</content>
</entry>
<entry>
<title>x86/cpu: Provide an AMD/HYGON specific topology parser</title>
<updated>2024-02-15T21:07:37+00:00</updated>
<author>
<name>Thomas Gleixner</name>
<email>tglx@linutronix.de</email>
</author>
<published>2024-02-13T21:04:11+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=f7fb3b2dd92c633871b7037773b89531c488a371'/>
<id>f7fb3b2dd92c633871b7037773b89531c488a371</id>
<content type='text'>
AMD/HYGON uses various methods for topology evaluation:

  - Leaf 0x80000008 and 0x8000001e based with an optional leaf 0xb,
    which is the preferred variant for modern CPUs.

    Leaf 0xb will be superseded by leaf 0x80000026 soon, which is just
    another variant of the Intel 0x1f leaf for whatever reasons.
    
  - Subleaf 0x80000008 and NODEID_MSR base

  - Legacy fallback

That code is following the principle of random bits and pieces all over the
place which results in multiple evaluations and impenetrable code flows in
the same way as the Intel parsing did.

Provide a sane implementation by clearly separating the three variants and
bringing them in the proper preference order in one place.

This provides the parsing for both AMD and HYGON because there is no point
in having a separate HYGON parser which only differs by 3 lines of
code. Any further divergence between AMD and HYGON can be handled in
different functions, while still sharing the existing parsers.

Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Tested-by: Juergen Gross &lt;jgross@suse.com&gt;
Tested-by: Sohil Mehta &lt;sohil.mehta@intel.com&gt;
Tested-by: Michael Kelley &lt;mhklinux@outlook.com&gt;
Tested-by: Zhang Rui &lt;rui.zhang@intel.com&gt;
Tested-by: Wang Wendy &lt;wendy.wang@intel.com&gt;
Tested-by: K Prateek Nayak &lt;kprateek.nayak@amd.com&gt;
Link: https://lore.kernel.org/r/20240212153625.020038641@linutronix.de

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<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
AMD/HYGON uses various methods for topology evaluation:

  - Leaf 0x80000008 and 0x8000001e based with an optional leaf 0xb,
    which is the preferred variant for modern CPUs.

    Leaf 0xb will be superseded by leaf 0x80000026 soon, which is just
    another variant of the Intel 0x1f leaf for whatever reasons.
    
  - Subleaf 0x80000008 and NODEID_MSR base

  - Legacy fallback

That code is following the principle of random bits and pieces all over the
place which results in multiple evaluations and impenetrable code flows in
the same way as the Intel parsing did.

Provide a sane implementation by clearly separating the three variants and
bringing them in the proper preference order in one place.

This provides the parsing for both AMD and HYGON because there is no point
in having a separate HYGON parser which only differs by 3 lines of
code. Any further divergence between AMD and HYGON can be handled in
different functions, while still sharing the existing parsers.

Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Tested-by: Juergen Gross &lt;jgross@suse.com&gt;
Tested-by: Sohil Mehta &lt;sohil.mehta@intel.com&gt;
Tested-by: Michael Kelley &lt;mhklinux@outlook.com&gt;
Tested-by: Zhang Rui &lt;rui.zhang@intel.com&gt;
Tested-by: Wang Wendy &lt;wendy.wang@intel.com&gt;
Tested-by: K Prateek Nayak &lt;kprateek.nayak@amd.com&gt;
Link: https://lore.kernel.org/r/20240212153625.020038641@linutronix.de

</pre>
</div>
</content>
</entry>
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