diff options
| author | Richard Henderson <richard.henderson@linaro.org> | 2023-05-19 18:30:28 -0700 |
|---|---|---|
| committer | Richard Henderson <richard.henderson@linaro.org> | 2023-05-23 18:54:55 -0700 |
| commit | 21c38f31c0f1d185feaefe39c367a12225b29089 (patch) | |
| tree | e7e518a75ae1c6d8964194b7ca9ad97f1af7d68d /host/include/aarch64 | |
| parent | 4deb39ebb33d97e2ad5466e1b5b5e7c50ad83a0a (diff) | |
qemu/atomic128: Split atomic16_read
Create both atomic16_read_ro and atomic16_read_rw.
Previously we pretended that we had atomic16_read in system mode,
because we "know" that all ram is always writable to the host.
Now, expose read-only and read-write versions all of the time.
For aarch64, do not fall back to __atomic_read_16 even if
supported by the compiler, to work around a clang bug.
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Diffstat (limited to 'host/include/aarch64')
| -rw-r--r-- | host/include/aarch64/host/atomic128-ldst.h | 21 |
1 files changed, 12 insertions, 9 deletions
diff --git a/host/include/aarch64/host/atomic128-ldst.h b/host/include/aarch64/host/atomic128-ldst.h index bd61fce50d..4b1360de39 100644 --- a/host/include/aarch64/host/atomic128-ldst.h +++ b/host/include/aarch64/host/atomic128-ldst.h @@ -11,10 +11,18 @@ #ifndef AARCH64_ATOMIC128_LDST_H #define AARCH64_ATOMIC128_LDST_H -/* Through gcc 10, aarch64 has no support for 128-bit atomics. */ -#if !defined(CONFIG_ATOMIC128) && !defined(CONFIG_USER_ONLY) -/* We can do better than cmpxchg for AArch64. */ -static inline Int128 atomic16_read(Int128 *ptr) +/* + * Through gcc 10, aarch64 has no support for 128-bit atomics. + * Through clang 16, without -march=armv8.4-a, __atomic_load_16 + * is incorrectly expanded to a read-write operation. + */ + +#define HAVE_ATOMIC128_RO 0 +#define HAVE_ATOMIC128_RW 1 + +Int128 QEMU_ERROR("unsupported atomic") atomic16_read_ro(const Int128 *ptr); + +static inline Int128 atomic16_read_rw(Int128 *ptr) { uint64_t l, h; uint32_t tmp; @@ -41,9 +49,4 @@ static inline void atomic16_set(Int128 *ptr, Int128 val) : [l] "r"(l), [h] "r"(h)); } -# define HAVE_ATOMIC128 1 -#else -#include "host/include/generic/host/atomic128-ldst.h" -#endif - #endif /* AARCH64_ATOMIC128_LDST_H */ |