From 154691335e242ca82a4de642d0737b4b972ec878 Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Thu, 18 May 2023 08:37:08 -0700 Subject: [PATCH] include/host: Split out atomic128-ldst.h MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Separates the aarch64-specific portion into its own file. Reviewed-by: Alex Bennée Signed-off-by: Richard Henderson --- host/include/aarch64/host/atomic128-ldst.h | 49 ++++++++++++++ host/include/generic/host/atomic128-ldst.h | 57 +++++++++++++++++ include/qemu/atomic128.h | 74 +--------------------- 3 files changed, 107 insertions(+), 73 deletions(-) create mode 100644 host/include/aarch64/host/atomic128-ldst.h create mode 100644 host/include/generic/host/atomic128-ldst.h diff --git a/host/include/aarch64/host/atomic128-ldst.h b/host/include/aarch64/host/atomic128-ldst.h new file mode 100644 index 0000000000..bd61fce50d --- /dev/null +++ b/host/include/aarch64/host/atomic128-ldst.h @@ -0,0 +1,49 @@ +/* + * SPDX-License-Identifier: GPL-2.0-or-later + * Load/store for 128-bit atomic operations, AArch64 version. + * + * Copyright (C) 2018, 2023 Linaro, Ltd. + * + * See docs/devel/atomics.rst for discussion about the guarantees each + * atomic primitive is meant to provide. + */ + +#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) +{ + uint64_t l, h; + uint32_t tmp; + + /* The load must be paired with the store to guarantee not tearing. */ + asm("0: ldxp %[l], %[h], %[mem]\n\t" + "stxp %w[tmp], %[l], %[h], %[mem]\n\t" + "cbnz %w[tmp], 0b" + : [mem] "+m"(*ptr), [tmp] "=r"(tmp), [l] "=r"(l), [h] "=r"(h)); + + return int128_make128(l, h); +} + +static inline void atomic16_set(Int128 *ptr, Int128 val) +{ + uint64_t l = int128_getlo(val), h = int128_gethi(val); + uint64_t t1, t2; + + /* Load into temporaries to acquire the exclusive access lock. */ + asm("0: ldxp %[t1], %[t2], %[mem]\n\t" + "stxp %w[t1], %[l], %[h], %[mem]\n\t" + "cbnz %w[t1], 0b" + : [mem] "+m"(*ptr), [t1] "=&r"(t1), [t2] "=&r"(t2) + : [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 */ diff --git a/host/include/generic/host/atomic128-ldst.h b/host/include/generic/host/atomic128-ldst.h new file mode 100644 index 0000000000..e7354a9255 --- /dev/null +++ b/host/include/generic/host/atomic128-ldst.h @@ -0,0 +1,57 @@ +/* + * SPDX-License-Identifier: GPL-2.0-or-later + * Load/store for 128-bit atomic operations, generic version. + * + * Copyright (C) 2018, 2023 Linaro, Ltd. + * + * See docs/devel/atomics.rst for discussion about the guarantees each + * atomic primitive is meant to provide. + */ + +#ifndef HOST_ATOMIC128_LDST_H +#define HOST_ATOMIC128_LDST_H + +#if defined(CONFIG_ATOMIC128) +static inline Int128 atomic16_read(Int128 *ptr) +{ + Int128Alias r; + + r.i = qatomic_read__nocheck((__int128_t *)ptr); + return r.s; +} + +static inline void atomic16_set(Int128 *ptr, Int128 val) +{ + Int128Alias v; + + v.s = val; + qatomic_set__nocheck((__int128_t *)ptr, v.i); +} + +# define HAVE_ATOMIC128 1 +#elif !defined(CONFIG_USER_ONLY) && HAVE_CMPXCHG128 +static inline Int128 atomic16_read(Int128 *ptr) +{ + /* Maybe replace 0 with 0, returning the old value. */ + Int128 z = int128_make64(0); + return atomic16_cmpxchg(ptr, z, z); +} + +static inline void atomic16_set(Int128 *ptr, Int128 val) +{ + Int128 old = *ptr, cmp; + do { + cmp = old; + old = atomic16_cmpxchg(ptr, cmp, val); + } while (int128_ne(old, cmp)); +} + +# define HAVE_ATOMIC128 1 +#else +/* Fallback definitions that must be optimized away, or error. */ +Int128 QEMU_ERROR("unsupported atomic") atomic16_read(Int128 *ptr); +void QEMU_ERROR("unsupported atomic") atomic16_set(Int128 *ptr, Int128 val); +# define HAVE_ATOMIC128 0 +#endif + +#endif /* HOST_ATOMIC128_LDST_H */ diff --git a/include/qemu/atomic128.h b/include/qemu/atomic128.h index 10a2322c44..3a8adb4d47 100644 --- a/include/qemu/atomic128.h +++ b/include/qemu/atomic128.h @@ -42,78 +42,6 @@ */ #include "host/atomic128-cas.h" - -#if defined(CONFIG_ATOMIC128) -static inline Int128 atomic16_read(Int128 *ptr) -{ - Int128Alias r; - - r.i = qatomic_read__nocheck((__int128_t *)ptr); - return r.s; -} - -static inline void atomic16_set(Int128 *ptr, Int128 val) -{ - Int128Alias v; - - v.s = val; - qatomic_set__nocheck((__int128_t *)ptr, v.i); -} - -# define HAVE_ATOMIC128 1 -#elif !defined(CONFIG_USER_ONLY) && defined(__aarch64__) -/* We can do better than cmpxchg for AArch64. */ -static inline Int128 atomic16_read(Int128 *ptr) -{ - uint64_t l, h; - uint32_t tmp; - - /* The load must be paired with the store to guarantee not tearing. */ - asm("0: ldxp %[l], %[h], %[mem]\n\t" - "stxp %w[tmp], %[l], %[h], %[mem]\n\t" - "cbnz %w[tmp], 0b" - : [mem] "+m"(*ptr), [tmp] "=r"(tmp), [l] "=r"(l), [h] "=r"(h)); - - return int128_make128(l, h); -} - -static inline void atomic16_set(Int128 *ptr, Int128 val) -{ - uint64_t l = int128_getlo(val), h = int128_gethi(val); - uint64_t t1, t2; - - /* Load into temporaries to acquire the exclusive access lock. */ - asm("0: ldxp %[t1], %[t2], %[mem]\n\t" - "stxp %w[t1], %[l], %[h], %[mem]\n\t" - "cbnz %w[t1], 0b" - : [mem] "+m"(*ptr), [t1] "=&r"(t1), [t2] "=&r"(t2) - : [l] "r"(l), [h] "r"(h)); -} - -# define HAVE_ATOMIC128 1 -#elif !defined(CONFIG_USER_ONLY) && HAVE_CMPXCHG128 -static inline Int128 atomic16_read(Int128 *ptr) -{ - /* Maybe replace 0 with 0, returning the old value. */ - Int128 z = int128_make64(0); - return atomic16_cmpxchg(ptr, z, z); -} - -static inline void atomic16_set(Int128 *ptr, Int128 val) -{ - Int128 old = *ptr, cmp; - do { - cmp = old; - old = atomic16_cmpxchg(ptr, cmp, val); - } while (int128_ne(old, cmp)); -} - -# define HAVE_ATOMIC128 1 -#else -/* Fallback definitions that must be optimized away, or error. */ -Int128 QEMU_ERROR("unsupported atomic") atomic16_read(Int128 *ptr); -void QEMU_ERROR("unsupported atomic") atomic16_set(Int128 *ptr, Int128 val); -# define HAVE_ATOMIC128 0 -#endif /* Some definition for HAVE_ATOMIC128 */ +#include "host/atomic128-ldst.h" #endif /* QEMU_ATOMIC128_H */