[PATCH v1] arm64: allow building with kcov coverage on ARM64

[Alexander Potapenko <glider@google.com>]

Add ARCH_HAS_KCOV to ARM64 config. Disable instrumentation of
arch/arm64/lib/delay.c

Signed-off-by: Alexander Potapenko <glider@google.com>
---
 arch/arm64/Kconfig      | 1 +
 arch/arm64/lib/Makefile | 3 +++
 2 files changed, 4 insertions(+)

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 4f43622..c52aa61 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -7,6 +7,7 @@ config ARM64
 	select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
 	select ARCH_HAS_ELF_RANDOMIZE
 	select ARCH_HAS_GCOV_PROFILE_ALL
+	select ARCH_HAS_KCOV
 	select ARCH_HAS_SG_CHAIN
 	select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
 	select ARCH_USE_CMPXCHG_LOCKREF
diff --git a/arch/arm64/lib/Makefile b/arch/arm64/lib/Makefile
index c86b790..b407bc1 100644
--- a/arch/arm64/lib/Makefile
+++ b/arch/arm64/lib/Makefile
@@ -1,3 +1,6 @@
+# Produces uninteresting flaky coverage.
+KCOV_INSTRUMENT_delay.o	:= n
+
 lib-y		:= bitops.o clear_user.o delay.o copy_from_user.o	\
 		   copy_to_user.o copy_in_user.o copy_page.o		\
 		   clear_page.o memchr.o memcpy.o memmove.o memset.o	\
-- 
2.8.0.rc3.226.g39d4020