linux_dsm_epyc7002/arch/arm64
James Morse 2b68a2a963 arm64: assembler: Switch ESB-instruction with a vanilla nop if !ARM64_HAS_RAS
The ESB-instruction is a nop on CPUs that don't implement the RAS
extensions. This lets us use it in places like the vectors without
having to use alternatives.

If someone disables CONFIG_ARM64_RAS_EXTN, this instruction still has
its RAS extensions behaviour, but we no longer read DISR_EL1 as this
register does depend on alternatives.

This could go wrong if we want to synchronize an SError from a KVM
guest. On a CPU that has the RAS extensions, but the KConfig option
was disabled, we consume the pending SError with no chance of ever
reading it.

Hide the ESB-instruction behind the CONFIG_ARM64_RAS_EXTN option,
outputting a regular nop if the feature has been disabled.

Reported-by: Julien Thierry <julien.thierry@arm.com>
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-07-05 13:03:29 +01:00
..
boot treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 332 2019-06-05 17:37:06 +02:00
configs ARM: SoC defconfig updates 2019-05-16 09:35:26 -07:00
crypto treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
include arm64: assembler: Switch ESB-instruction with a vanilla nop if !ARM64_HAS_RAS 2019-07-05 13:03:29 +01:00
kernel SPDX update for 5.2-rc6 2019-06-21 09:58:42 -07:00
kvm SPDX update for 5.2-rc6 2019-06-21 09:58:42 -07:00
lib treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
mm treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
net treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 234 2019-06-19 17:09:07 +02:00
xen treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
Kconfig Second round of arm64 fixes for -rc2 2019-05-24 11:03:26 -07:00
Kconfig.debug treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
Kconfig.platforms Texas Instruments AM65x fixes for v5.2 2019-06-16 13:30:30 -07:00
Makefile arm64: Don't unconditionally add -Wno-psabi to KBUILD_CFLAGS 2019-06-12 10:54:47 +01:00