linux-stable/arch/x86/kernel/cpu/microcode
Ashok Raj 93946a33b5 x86/microcode: Update late microcode in parallel
Microcode update was changed to be serialized due to restrictions after
Spectre days. Updating serially on a large multi-socket system can be
painful since it is being done on one CPU at a time.

Cloud customers have expressed discontent as services disappear for
a prolonged time. The restriction is that only one core (or only one
thread of a core in the case of an SMT system) goes through the update
while other cores (or respectively, SMT threads) are quiesced.

Do the microcode update only on the first thread of each core while
other siblings simply wait for this to complete.

 [ bp: Simplify, massage, cleanup comments. ]

Signed-off-by: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Mihai Carabas <mihai.carabas@oracle.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jon Grimm <Jon.Grimm@amd.com>
Cc: kanth.ghatraju@oracle.com
Cc: konrad.wilk@oracle.com
Cc: patrick.colp@oracle.com
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/1566506627-16536-2-git-send-email-mihai.carabas@oracle.com
2019-10-01 15:58:54 +02:00
..
amd.c x86/microcode/amd: Fix two -Wunused-but-set-variable warnings 2019-10-01 11:36:09 +02:00
core.c x86/microcode: Update late microcode in parallel 2019-10-01 15:58:54 +02:00
intel.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
Makefile treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00