linux_dsm_epyc7002/arch
Fenghua Yu b302e4b176 x86/cpufeatures: Enumerate the new AVX512 BFLOAT16 instructions
AVX512 BFLOAT16 instructions support 16-bit BFLOAT16 floating-point
format (BF16) for deep learning optimization.

BF16 is a short version of 32-bit single-precision floating-point
format (FP32) and has several advantages over 16-bit half-precision
floating-point format (FP16). BF16 keeps FP32 accumulation after
multiplication without loss of precision, offers more than enough
range for deep learning training tasks, and doesn't need to handle
hardware exception.

AVX512 BFLOAT16 instructions are enumerated in CPUID.7.1:EAX[bit 5]
AVX512_BF16.

CPUID.7.1:EAX contains only feature bits. Reuse the currently empty
word 12 as a pure features word to hold the feature bits including
AVX512_BF16.

Detailed information of the CPUID bit and AVX512 BFLOAT16 instructions
can be found in the latest Intel Architecture Instruction Set Extensions
and Future Features Programming Reference.

 [ bp: Check CPUID(7) subleaf validity before accessing subleaf 1. ]

Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: "Chang S. Bae" <chang.seok.bae@intel.com>
Cc: Frederic Weisbecker <frederic@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nadav Amit <namit@vmware.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Pavel Tatashin <pasha.tatashin@oracle.com>
Cc: Peter Feiner <pfeiner@google.com>
Cc: Radim Krcmar <rkrcmar@redhat.com>
Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Cc: "Ravi V Shankar" <ravi.v.shankar@intel.com>
Cc: Robert Hoo <robert.hu@linux.intel.com>
Cc: "Sean J Christopherson" <sean.j.christopherson@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Thomas Lendacky <Thomas.Lendacky@amd.com>
Cc: x86 <x86@kernel.org>
Link: https://lkml.kernel.org/r/1560794416-217638-3-git-send-email-fenghua.yu@intel.com
2019-06-20 12:38:49 +02:00
..
alpha treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 428 2019-06-05 17:37:16 +02:00
arc SPDX update for 5.2-rc4 2019-06-08 12:52:42 -07:00
arm treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441 2019-06-05 17:37:17 +02:00
arm64 SPDX update for 5.2-rc4 2019-06-08 12:52:42 -07:00
c6x treewide: Add SPDX license identifier - Kbuild 2019-05-30 11:32:33 -07:00
csky treewide: Add SPDX license identifier - Kbuild 2019-05-30 11:32:33 -07:00
h8300 treewide: Add SPDX license identifier - Kbuild 2019-05-30 11:32:33 -07:00
hexagon treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 267 2019-06-05 17:30:29 +02:00
ia64 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 428 2019-06-05 17:37:16 +02:00
m68k treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 285 2019-06-05 17:36:37 +02:00
microblaze treewide: Add SPDX license identifier - Kbuild 2019-05-30 11:32:33 -07:00
mips A batch of MIPS fixes: 2019-06-08 13:09:31 -07:00
nds32 nds32 patches for 5.2-rc3 2019-06-03 10:23:41 -07:00
nios2 treewide: Add SPDX license identifier - Kbuild 2019-05-30 11:32:33 -07:00
openrisc treewide: Add SPDX license identifier - Kbuild 2019-05-30 11:32:33 -07:00
parisc SPDX update for 5.2-rc4 2019-06-08 12:52:42 -07:00
powerpc treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 449 2019-06-05 17:37:18 +02:00
riscv treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 286 2019-06-05 17:36:37 +02:00
s390 s390/unwind: correct stack switching during unwind 2019-06-07 15:20:44 +02:00
sh treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 211 2019-05-30 11:29:53 -07:00
sparc SPDX update for 5.2-rc4 2019-06-08 12:52:42 -07:00
um treewide: Add SPDX license identifier - Kbuild 2019-05-30 11:32:33 -07:00
unicore32 treewide: Add SPDX license identifier - Kbuild 2019-05-30 11:32:33 -07:00
x86 x86/cpufeatures: Enumerate the new AVX512 BFLOAT16 instructions 2019-06-20 12:38:49 +02:00
xtensa Xtensa fixes for v5.2-rc4 2019-06-07 13:06:00 -07:00
.gitignore
Kconfig Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-05-16 11:00:20 -07:00