[PATCH 3.16 001/366] arm64: add missing data types in smp_load_acquire/smp_store_release

Ben Hutchings
2018-11-11T20:43:14Z

From: Andre Przywara <andre.przywara@arm.com>

commit 878a84d5a8a18a4ab241d40cebb791d6aedf5605 upstream.

Commit 8053871d0f7f ("smp: Fix smp_call_function_single_async()
locking") introduced a call to smp_load_acquire() with a u16 argument,
but we only cared about u32 and u64 types in that function so far.
This resulted in a compiler warning fortunately, pointing at an
uninitialized use. Due to the implementation structure the compiler
misses that bug in the smp_store_release(), though.
Add the u16 and u8 variants using ldarh/stlrh and ldarb/stlrb,
respectively. Together with the compiletime_assert_atomic_type() check
this should cover all cases now.

Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
arch/arm64/include/asm/barrier.h | 16 ++++++++++++++++
1 file changed, 16 insertions(+)

--- a/arch/arm64/include/asm/barrier.h
+++ b/arch/arm64/include/asm/barrier.h
@@ -64,6 +64,14 @@ do { \
{ .__val = (__force typeof(*p)) (v) }; \
compiletime_assert_atomic_type(*p); \
switch (sizeof(*p)) { \
+ case 1: \
+ asm volatile ("stlrb %w1, %0" \
+ : "=Q" (*p) : "r" (v) : "memory"); \
+ break; \
+ case 2: \
+ asm volatile ("stlrh %w1, %0" \
+ : "=Q" (*p) : "r" (v) : "memory"); \
+ break; \
case 4: \
asm volatile ("stlr %w1, %0" \
: "=Q" (*p) \
@@ -84,6 +92,14 @@ do { \
typeof(*p) ___p1; \
compiletime_assert_atomic_type(*p); \
switch (sizeof(*p)) { \
+ case 1: \
+ asm volatile ("ldarb %w0, %1" \
+ : "=r" (___p1) : "Q" (*p) : "memory"); \
+ break; \
+ case 2: \
+ asm volatile ("ldarh %w0, %1" \
+ : "=r" (___p1) : "Q" (*p) : "memory"); \
+ break; \
case 4: \
asm volatile ("ldar %w0, %1" \
: "=r" (___p1) : "Q" (*p) : "memory"); \