linux/arch/arm64
Peter Collingbourne 739003c642 arm64: mte: optimize asynchronous tag check fault flag check
We don't need to check for MTE support before checking the flag
because it can only be set if the hardware supports MTE. As a result
we can unconditionally check the flag bit which is expected to be in
a register and therefore the check can be done in a single instruction
instead of first needing to load the hwcaps.

On a DragonBoard 845c with a kernel built with CONFIG_ARM64_MTE=y with
the powersave governor this reduces the cost of a kernel entry/exit
(invalid syscall) from 465.1ns to 463.8ns.

Signed-off-by: Peter Collingbourne <pcc@google.com>
Link: https://linux-review.googlesource.com/id/If4dc3501fd4e4f287322f17805509613cfe47d24
Link: https://lore.kernel.org/r/20201118032051.1405907-1-pcc@google.com
[catalin.marinas@arm.com: remove IS_ENABLED(CONFIG_ARM64_MTE)]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-11-18 17:12:11 +00:00
..
boot Amlogic fixes for v5.10-rc1 2020-10-27 10:44:11 +01:00
configs arm64: defconfig: Build in CONFIG_GPIO_MXC by default 2020-10-26 15:48:58 +08:00
crypto Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2020-10-13 08:50:16 -07:00
include arm64: consistently use reserved_pg_dir 2020-11-10 17:30:40 +00:00
kernel arm64: mte: optimize asynchronous tag check fault flag check 2020-11-18 17:12:11 +00:00
kvm ARM: 2020-11-01 09:43:32 -08:00
lib arm64: Change .weak to SYM_FUNC_START_WEAK_PI for arch/arm64/lib/mem*.S 2020-10-30 08:32:31 +00:00
mm arm64/mm: add fallback option to allocate virtually contiguous memory 2020-11-17 18:21:01 +00:00
net arm64: bpf: Fix branch offset in JIT 2020-09-17 12:05:36 +01:00
xen
Kbuild
Kconfig arm64: NUMA: Kconfig: Increase NODES_SHIFT to 4 2020-11-03 09:31:53 +00:00
Kconfig.debug arm64: remove TEXT_OFFSET randomization 2020-06-15 13:10:59 +01:00
Kconfig.platforms arm64: berlin: Select DW_APB_TIMER_OF 2020-10-26 10:45:03 +01:00
Makefile More arm64 updates for 5.10 2020-10-23 09:46:16 -07:00