linux-stable.git/arch/x86/kernel/cpu/amd.c, branch linux-4.8.y

x86/cpu/AMD: Fix cpu_llc_id for AMD Fam17h systems

2016-11-26T08:56:53+00:00

commit b0b6e86846093c5f8820386bc01515f857dd8faa upstream.

cpu_llc_id (Last Level Cache ID) derivation on AMD Fam17h has an
underflow bug when extracting the socket_id value. It starts from 0
so subtracting 1 from it will result in an invalid value. This breaks
scheduling topology later on since the cpu_llc_id will be incorrect.

For example, the the cpu_llc_id of the *other* CPU in the loops in
set_cpu_sibling_map() underflows and we're generating the funniest
thread_siblings masks and then when I run 8 threads of nbench, they get
spread around the LLC domains in a very strange pattern which doesn't
give you the normal scheduling spread one would expect for performance.

Other things like EDAC use cpu_llc_id so they will be b0rked too.

So, the APIC ID is preset in APICx020 for bits 3 and above: they contain
the core complex, node and socket IDs.

The LLC is at the core complex level so we can find a unique cpu_llc_id
by right shifting the APICID by 3 because then the least significant bit
will be the Core Complex ID.

Tested-by: Borislav Petkov 
Signed-off-by: Yazen Ghannam 
[ Cleaned up and extended the commit message. ]
Signed-off-by: Borislav Petkov 
Acked-by: Thomas Gleixner 
Cc: Aravind Gopalakrishnan 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Fixes: 3849e91f571d ("x86/AMD: Fix last level cache topology for AMD Fam17h systems")
Link: http://lkml.kernel.org/r/20161108083506.rvqb5h4chrcptj7d@pd.tnic
Signed-off-by: Ingo Molnar 
Signed-off-by: Greg Kroah-Hartman

x86/AMD: Apply erratum 665 on machines without a BIOS fix

2016-09-02T18:42:28+00:00

AMD F12h machines have an erratum which can cause DIV/IDIV to behave
unpredictably. The workaround is to set MSRC001_1029[31] but sometimes
there is no BIOS update containing that workaround so let's do it
ourselves unconditionally. It is simple enough.

[ Borislav: Wrote commit message. ]

Signed-off-by: Emanuel Czirai 
Signed-off-by: Borislav Petkov 
Cc: Yaowu Xu 
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/20160902053550.18097-1-bp@alien8.de
Signed-off-by: Thomas Gleixner

x86/cpu/AMD: Extend X86_FEATURE_TOPOEXT workaround to newer models

2016-06-08T11:51:34+00:00

We need to reenable the topology extensions CPUID leafs on newer models
too, if BIOS has disabled them, as we rely on them to get proper compute
unit topology.

Make the printk a once thing, while at it.

Signed-off-by: Borislav Petkov 
Cc: Andy Lutomirski 
Cc: Borislav Petkov 
Cc: Brian Gerst 
Cc: Denys Vlasenko 
Cc: H. Peter Anvin 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Rui Huang 
Cc: Sherry Hurwitz 
Cc: Thomas Gleixner 
Cc: linux-hwmon@vger.kernel.org
Link: http://lkml.kernel.org/r/1464775468-23355-1-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar

x86/cpu: Simplify extended APIC ID detection on AMD

2016-04-13T09:37:42+00:00

Both if-branches are under if (boot_cpu_has(X86_FEATURE_APIC)), unify
them.

Also, simplify the test for bits:

- 17 ("ApicExtBrdCst: APIC extended broadcast enable") and
- 18 ("ApicExtId: APIC extended ID enable.")

in "D18F0x68 Link Transaction Control."

No functionality change.

Signed-off-by: Borislav Petkov 
Cc: Andy Lutomirski 
Cc: Borislav Petkov 
Cc: Brian Gerst 
Cc: Denys Vlasenko 
Cc: H. Peter Anvin 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/r/1459837795-2588-3-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar

x86/cpufeature: Replace cpu_has_apic with boot_cpu_has() usage

2016-04-13T09:37:41+00:00

Signed-off-by: Borislav Petkov 
Cc: Andy Lutomirski 
Cc: Borislav Petkov 
Cc: Brian Gerst 
Cc: Denys Vlasenko 
Cc: H. Peter Anvin 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: iommu@lists.linux-foundation.org
Cc: linux-pm@vger.kernel.org
Cc: oprofile-list@lists.sf.net
Link: http://lkml.kernel.org/r/1459801503-15600-8-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar

Merge branch 'x86/urgent' into x86/asm to pick up dependent fixes

2016-04-13T09:36:44+00:00

Signed-off-by: Ingo Molnar

Merge branch 'x86/cpu' into x86/asm, to merge more patches

2016-04-13T09:15:39+00:00

Signed-off-by: Ingo Molnar

x86/cpu: Add Erratum 88 detection on AMD

2016-04-13T08:20:42+00:00

Erratum 88 affects old AMD K8s, where a SWAPGS fails to cause an input
dependency on GS. Therefore, we need to MFENCE before it.

But that MFENCE is expensive and unnecessary on the remaining x86 CPUs
out there so patch it out on the CPUs which don't require it.

Signed-off-by: Borislav Petkov 
Signed-off-by: Andy Lutomirski 
Cc: Borislav Petkov 
Cc: Brian Gerst 
Cc: Denys Vlasenko 
Cc: H. Peter Anvin 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Rudolf Marek 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/r/aec6b2df1bfc56101d4e9e2e5d5d570bf41663c6.1460075211.git.luto@kernel.org
Signed-off-by: Ingo Molnar

x86/cpufeature: Remove cpu_has_xmm2

2016-03-31T11:35:09+00:00

Signed-off-by: Borislav Petkov 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: linux-crypto@vger.kernel.org
Link: http://lkml.kernel.org/r/1459266123-21878-8-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar

x86/cpu: Get rid of compute_unit_id

2016-03-29T08:45:04+00:00

It is cpu_core_id anyway.

Signed-off-by: Borislav Petkov 
Link: http://lkml.kernel.org/r/1458917557-8757-3-git-send-email-bp@alien8.de
Signed-off-by: Thomas Gleixner