BMC/Intel-BMC/linux.git/arch/x86/include/asm/processor.h, branch dev-4.10

x86/CPU/AMD: Bring back Compute Unit ID

2017-02-05T11:18:45+00:00

Commit: a33d331761bc ("x86/CPU/AMD: Fix Bulldozer topology") restored the initial approach we had with the Fam15h topology of enumerating CU (Compute Unit) threads as cores. And this is still correct - they're beefier than HT threads but still have some shared functionality. Our current approach has a problem with the Mad Max Steam game, for example. Yves Dionne reported a certain "choppiness" while playing on v4.9.5. That problem stems most likely from the fact that the CU threads share resources within one CU and when we schedule to a thread of a different compute unit, this incurs latency due to migrating the working set to a different CU through the caches. When the thread siblings mask mirrors that aspect of the CUs and threads, the scheduler pays attention to it and tries to schedule within one CU first. Which takes care of the latency, of course. Reported-by: Yves Dionne Signed-off-by: Borislav Petkov Cc: # 4.9 Cc: Brice Goglin Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Yazen Ghannam Link: http://lkml.kernel.org/r/20170205105022.8705-1-bp@alien8.de Signed-off-by: Ingo Molnar

x86/CPU: Add native CPUID variants returning a single datum

2017-01-09T22:11:13+00:00

... similarly to the cpuid_() variants. Signed-off-by: Borislav Petkov Link: http://lkml.kernel.org/r/20170109114147.5082-2-bp@alien8.de Signed-off-by: Thomas Gleixner

x86/asm: Rewrite sync_core() to use IRET-to-self

2016-12-19T10:54:21+00:00

Aside from being excessively slow, CPUID is problematic: Linux runs on a handful of CPUs that don't have CPUID. Use IRET-to-self instead. IRET-to-self works everywhere, so it makes testing easy. For reference, On my laptop, IRET-to-self is ~110ns, CPUID(eax=1, ecx=0) is ~83ns on native and very very slow under KVM, and MOV-to-CR2 is ~42ns. While we're at it: sync_core() serves a very specific purpose. Document it. Signed-off-by: Andy Lutomirski Cc: Juergen Gross Cc: One Thousand Gnomes Cc: Peter Zijlstra Cc: Brian Gerst Cc: Matthew Whitehead Cc: Borislav Petkov Cc: Henrique de Moraes Holschuh Cc: Andrew Cooper Cc: Boris Ostrovsky Cc: xen-devel Link: http://lkml.kernel.org/r/5c79f0225f68bc8c40335612bf624511abb78941.1481307769.git.luto@kernel.org Signed-off-by: Thomas Gleixner

x86/asm/32: Make sync_core() handle missing CPUID on all 32-bit kernels

2016-12-19T10:54:20+00:00

We support various non-Intel CPUs that don't have the CPUID instruction, so the M486 test was wrong. For now, fix it with a big hammer: handle missing CPUID on all 32-bit CPUs. Reported-by: One Thousand Gnomes Signed-off-by: Andy Lutomirski Cc: Juergen Gross Cc: Peter Zijlstra Cc: Brian Gerst Cc: Matthew Whitehead Cc: Borislav Petkov Cc: Henrique de Moraes Holschuh Cc: Andrew Cooper Cc: Boris Ostrovsky Cc: xen-devel Link: http://lkml.kernel.org/r/685bd083a7c036f7769510b6846315b17d6ba71f.1481307769.git.luto@kernel.org Signed-off-by: Thomas Gleixner

Merge branch 'x86-idle-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2016-12-12T22:55:04+00:00

Pull x86 idle updates from Ingo Molnar: "There were two bigger changes in this development cycle: - remove idle notifiers: 32 files changed, 74 insertions(+), 803 deletions(-) These notifiers were of questionable value and the main usecase, the i7300 driver, was essentially unmaintained and can be removed, plus modern power management concepts don't need the callback - so use this golden opportunity and get rid of this opaque and fragile callback from a latency sensitive code path. (Len Brown, Thomas Gleixner) - improve the AMD Erratum 400 workaround that used high overhead MSR polling in the idle loop (Borisla Petkov, Thomas Gleixner)" * 'x86-idle-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86: Remove empty idle.h header x86/amd: Simplify AMD E400 aware idle routine x86/amd: Check for the C1E bug post ACPI subsystem init x86/bugs: Separate AMD E400 erratum and C1E bug x86/cpufeature: Provide helper to set bugs bits x86/idle: Remove enter_idle(), exit_idle() x86: Remove x86_test_and_clear_bit_percpu() x86/idle: Remove is_idle flag x86/idle: Remove idle_notifier i7300_idle: Remove this driver

Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2016-12-12T21:49:57+00:00

Pull x86 asm updates from Ingo Molnar: "The main changes in this development cycle were: - a large number of call stack dumping/printing improvements: higher robustness, better cross-context dumping, improved output, etc. (Josh Poimboeuf) - vDSO getcpu() performance improvement for future Intel CPUs with the RDPID instruction (Andy Lutomirski) - add two new Intel AVX512 features and the CPUID support infrastructure for it: AVX512IFMA and AVX512VBMI. (Gayatri Kammela, He Chen) - more copy-user unification (Borislav Petkov) - entry code assembly macro simplifications (Alexander Kuleshov) - vDSO C/R support improvements (Dmitry Safonov) - misc fixes and cleanups (Borislav Petkov, Paul Bolle)" * 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (40 commits) scripts/decode_stacktrace.sh: Fix address line detection on x86 x86/boot/64: Use defines for page size x86/dumpstack: Make stack name tags more comprehensible selftests/x86: Add test_vdso to test getcpu() x86/vdso: Use RDPID in preference to LSL when available x86/dumpstack: Handle NULL stack pointer in show_trace_log_lvl() x86/cpufeatures: Enable new AVX512 cpu features x86/cpuid: Provide get_scattered_cpuid_leaf() x86/cpuid: Cleanup cpuid_regs definitions x86/copy_user: Unify the code by removing the 64-bit asm _copy_*_user() variants x86/unwind: Ensure stack grows down x86/vdso: Set vDSO pointer only after success x86/prctl/uapi: Remove #ifdef for CHECKPOINT_RESTORE x86/unwind: Detect bad stack return address x86/dumpstack: Warn on stack recursion x86/unwind: Warn on bad frame pointer x86/decoder: Use stderr if insn sanity test fails x86/decoder: Use stdout if insn decoder test is successful mm/page_alloc: Remove kernel address exposure in free_reserved_area() x86/dumpstack: Remove raw stack dump ...

x86/amd: Simplify AMD E400 aware idle routine

2016-12-09T20:23:21+00:00

Reorganize the E400 detection now that we have everything in place: switch the CPUs to broadcast mode after the LAPIC has been initialized and remove the facilities that were used previously on the idle path. Unfortunately static_cpu_has_bug() cannpt be used in the E400 idle routine because alternatives have been applied when the actual detection happens, so the static switching does not take effect and the test will stay false. Use boot_cpu_has_bug() instead which is definitely an improvement over the RDMSR and the cpumask handling. Suggested-by: Thomas Gleixner Signed-off-by: Borislav Petkov Cc: Jiri Olsa Link: http://lkml.kernel.org/r/20161209182912.2726-5-bp@alien8.de Signed-off-by: Thomas Gleixner

locking/core: Provide common cpu_relax_yield() definition

2016-11-17T07:17:36+00:00

No need to duplicate the same define everywhere. Since the only user is stop-machine and the only provider is s390, we can use a default implementation of cpu_relax_yield() in sched.h. Suggested-by: Russell King Signed-off-by: Christian Borntraeger Reviewed-by: David Hildenbrand Acked-by: Russell King Cc: Andrew Morton Cc: Catalin Marinas Cc: Heiko Carstens Cc: Linus Torvalds Cc: Martin Schwidefsky Cc: Nicholas Piggin Cc: Noam Camus Cc: Paul E. McKenney Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Will Deacon Cc: kvm@vger.kernel.org Cc: linux-arch@vger.kernel.org Cc: linux-s390 Cc: linuxppc-dev@lists.ozlabs.org Cc: sparclinux@vger.kernel.org Cc: virtualization@lists.linux-foundation.org Cc: xen-devel@lists.xenproject.org Link: http://lkml.kernel.org/r/1479298985-191589-1-git-send-email-borntraeger@de.ibm.com Signed-off-by: Ingo Molnar

x86/cpuid: Provide get_scattered_cpuid_leaf()

2016-11-16T10:13:09+00:00

Sparse populated CPUID leafs are collected in a software provided leaf to avoid bloat of the x86_capability array, but there is no way to rebuild the real leafs (e.g. for KVM CPUID enumeration) other than rereading the CPUID leaf from the CPU. While this is possible it is problematic as it does not take software disabled features into account. If a feature is disabled on the host it should not be exposed to a guest either. Add get_scattered_cpuid_leaf() which rebuilds the leaf from the scattered cpuid table information and the active CPU features. [ tglx: Rewrote changelog ] Signed-off-by: He Chen Reviewed-by: Borislav Petkov Cc: Luwei Kang Cc: kvm@vger.kernel.org Cc: Radim Krčmář Cc: Piotr Luc Cc: Borislav Petkov Cc: Paolo Bonzini Link: http://lkml.kernel.org/r/1478856336-9388-3-git-send-email-he.chen@linux.intel.com Signed-off-by: Thomas Gleixner

x86/cpuid: Cleanup cpuid_regs definitions

2016-11-16T10:13:09+00:00

cpuid_regs is defined multiple times as structure and enum. Rename the enum and move all of it to processor.h so we don't end up with more instances. Rename the misnomed register enumeration from CR_* to the obvious CPUID_*. [ tglx: Rewrote changelog ] Signed-off-by: He Chen Reviewed-by: Borislav Petkov Cc: Luwei Kang Cc: kvm@vger.kernel.org Cc: Radim Krčmář Cc: Piotr Luc Cc: Paolo Bonzini Link: http://lkml.kernel.org/r/1478856336-9388-2-git-send-email-he.chen@linux.intel.com Signed-off-by: Thomas Gleixner