The rte_wait_until_equalxx APIs abstract the functionality of 'polling for a memory location to become equal to a given value'.
Signed-off-by: Gavin Hu <gavin...@arm.com> Reviewed-by: Ruifeng Wang <ruifeng.w...@arm.com> Reviewed-by: Steve Capper <steve.cap...@arm.com> Reviewed-by: Ola Liljedahl <ola.liljed...@arm.com> Reviewed-by: Honnappa Nagarahalli <honnappa.nagaraha...@arm.com> Reviewed-by: Phil Yang <phil.y...@arm.com> Acked-by: Pavan Nikhilesh <pbhagavat...@marvell.com> --- .../common/include/arch/arm/rte_pause_64.h | 30 +++++++ lib/librte_eal/common/include/generic/rte_pause.h | 98 +++++++++++++++++++++- 2 files changed, 127 insertions(+), 1 deletion(-) diff --git a/lib/librte_eal/common/include/arch/arm/rte_pause_64.h b/lib/librte_eal/common/include/arch/arm/rte_pause_64.h index 93895d3..dabde17 100644 --- a/lib/librte_eal/common/include/arch/arm/rte_pause_64.h +++ b/lib/librte_eal/common/include/arch/arm/rte_pause_64.h @@ -1,5 +1,6 @@ /* SPDX-License-Identifier: BSD-3-Clause * Copyright(c) 2017 Cavium, Inc + * Copyright(c) 2019 Arm Limited */ #ifndef _RTE_PAUSE_ARM64_H_ @@ -17,6 +18,35 @@ static inline void rte_pause(void) asm volatile("yield" ::: "memory"); } +#ifdef RTE_ARM_USE_WFE +#define __WAIT_UNTIL_EQUAL(name, asm_op, wide, type) \ +static __rte_always_inline void \ +rte_wait_until_equal_##name(volatile type * addr, type expected) \ +{ \ + type tmp; \ + asm volatile( \ + #asm_op " %" #wide "[tmp], %[addr]\n" \ + "cmp %" #wide "[tmp], %" #wide "[expected]\n" \ + "b.eq 2f\n" \ + "sevl\n" \ + "1: wfe\n" \ + #asm_op " %" #wide "[tmp], %[addr]\n" \ + "cmp %" #wide "[tmp], %" #wide "[expected]\n" \ + "bne 1b\n" \ + "2:\n" \ + : [tmp] "=&r" (tmp) \ + : [addr] "Q"(*addr), [expected] "r"(expected) \ + : "cc", "memory"); \ +} +/* Wait for *addr to be updated with expected value */ +__WAIT_UNTIL_EQUAL(relaxed_16, ldxrh, w, uint16_t) +__WAIT_UNTIL_EQUAL(acquire_16, ldaxrh, w, uint16_t) +__WAIT_UNTIL_EQUAL(relaxed_32, ldxr, w, uint32_t) +__WAIT_UNTIL_EQUAL(acquire_32, ldaxr, w, uint32_t) +__WAIT_UNTIL_EQUAL(relaxed_64, ldxr, x, uint64_t) +__WAIT_UNTIL_EQUAL(acquire_64, ldaxr, x, uint64_t) +#endif + #ifdef __cplusplus } #endif diff --git a/lib/librte_eal/common/include/generic/rte_pause.h b/lib/librte_eal/common/include/generic/rte_pause.h index 52bd4db..dfa6a53 100644 --- a/lib/librte_eal/common/include/generic/rte_pause.h +++ b/lib/librte_eal/common/include/generic/rte_pause.h @@ -1,10 +1,10 @@ /* SPDX-License-Identifier: BSD-3-Clause * Copyright(c) 2017 Cavium, Inc + * Copyright(c) 2019 Arm Limited */ #ifndef _RTE_PAUSE_H_ #define _RTE_PAUSE_H_ - /** * @file * @@ -12,6 +12,10 @@ * */ +#include <stdint.h> +#include <rte_common.h> +#include <rte_atomic.h> + /** * Pause CPU execution for a short while * @@ -20,4 +24,96 @@ */ static inline void rte_pause(void); +/** + * Wait for *addr to be updated with expected value + * + * @param addr + * A pointer to the memory location. + * @param expected + * An expected value to be in the memory location. + */ +__rte_always_inline +static void +rte_wait_until_equal_relaxed_16(volatile uint16_t *addr, uint16_t expected); + +/** + * Wait for *addr to be updated with expected value + * + * @param addr + * A pointer to the memory location. + * @param expected + * An expected value to be in the memory location. + */ +__rte_always_inline +static void +rte_wait_until_equal_relaxed_32(volatile uint32_t *addr, uint32_t expected); + +/** + * Wait for *addr to be updated with expected value + * + * @param addr + * A pointer to the memory location. + * @param expected + * An expected value to be in the memory location. + */ +__rte_always_inline +static void +rte_wait_until_equal_relaxed_64(volatile uint64_t *addr, uint64_t expected); + +/** + * Wait for *addr to be updated with expected value + * + * @param addr + * A pointer to the memory location. + * @param expected + * An expected value to be in the memory location. + */ +__rte_always_inline +static void +rte_wait_until_equal_acquire_16(volatile uint16_t *addr, uint16_t expected); + +/** + * Wait for *addr to be updated with expected value + * + * @param addr + * A pointer to the memory location. + * @param expected + * An expected value to be in the memory location. + */ +__rte_always_inline +static void +rte_wait_until_equal_acquire_32(volatile uint32_t *addr, uint32_t expected); + +/** + * Wait for *addr to be updated with expected value + * + * @param addr + * A pointer to the memory location. + * @param expected + * An expected value to be in the memory location. + */ +__rte_always_inline +static void +rte_wait_until_equal_acquire_64(volatile uint64_t *addr, uint64_t expected); + +#if !defined(RTE_ARM_USE_WFE) +#define __WAIT_UNTIL_EQUAL(op_name, size, type, memorder) \ +__rte_always_inline \ +static void \ +rte_wait_until_equal_##op_name##_##size(volatile type *addr, \ + type expected) \ +{ \ + while (__atomic_load_n(addr, memorder) != expected) \ + rte_pause(); \ +} + +/* Wait for *addr to be updated with expected value */ +__WAIT_UNTIL_EQUAL(relaxed, 16, uint16_t, __ATOMIC_RELAXED) +__WAIT_UNTIL_EQUAL(acquire, 16, uint16_t, __ATOMIC_ACQUIRE) +__WAIT_UNTIL_EQUAL(relaxed, 32, uint32_t, __ATOMIC_RELAXED) +__WAIT_UNTIL_EQUAL(acquire, 32, uint32_t, __ATOMIC_ACQUIRE) +__WAIT_UNTIL_EQUAL(relaxed, 64, uint64_t, __ATOMIC_RELAXED) +__WAIT_UNTIL_EQUAL(acquire, 64, uint64_t, __ATOMIC_ACQUIRE) +#endif /* RTE_ARM_USE_WFE */ + #endif /* _RTE_PAUSE_H_ */ -- 2.7.4