Messages in this thread Patch in this message | | | From | Andrey Ryabinin <> | Subject | [PATCH] arm64: Implement 1-,2- byte smp_load_acquire and smp_store_release | Date | Mon, 20 Apr 2015 18:45:53 +0300 |
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commit 47933ad41a86 ("arch: Introduce smp_load_acquire(), smp_store_release()") allowed only 4- and 8-byte smp_load_acquire, smp_store_release. So 1- and 2-byte cases weren't implemented in arm64. Later commit 536fa402221f ("compiler: Allow 1- and 2-byte smp_load_acquire() and smp_store_release()") allowed to use 1 and 2 byte smp_load_acquire and smp_store_release by adjusting the definition of __native_word(). However, 1-,2- byte cases in arm64 version left unimplemented.
Commit 8053871d0f7f ("smp: Fix smp_call_function_single_async() locking") started to use smp_load_acquire() to load 2-bytes csd->flags. That crashes arm64 kernel during the boot.
Implement 1,2 byte cases in arm64's smp_load_acquire() and smp_store_release() to fix this.
Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com> --- arch/arm64/include/asm/barrier.h | 16 ++++++++++++++++ 1 file changed, 16 insertions(+)
diff --git a/arch/arm64/include/asm/barrier.h b/arch/arm64/include/asm/barrier.h index a5abb00..71f19c4 100644 --- a/arch/arm64/include/asm/barrier.h +++ b/arch/arm64/include/asm/barrier.h @@ -65,6 +65,14 @@ do { \ do { \ 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) : "r" (v) : "memory"); \ @@ -81,6 +89,14 @@ 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"); \ -- 2.3.5
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