RISC-V currently has no-op implementations of the rte_prefetch* functions. Use __builtin_prefetch() to allow the compiler to emit Zicbop prefetch instructions when the target supports them (GCC 13.1+, Clang 17.0.1+ with -march=rv*_zicbop).
The Zicbop extension has no cache-level hints, so rte_prefetch1() and rte_prefetch2() fall back to rte_prefetch0(). The volatile qualifier is stripped via uintptr_t cast to satisfy __builtin_prefetch()'s const void * parameter without triggering -Wdiscarded-qualifiers. This replaces the abandoned v1 series by Daniel Gregory (Message-ID: [email protected]) addressing reviewer feedback from Kardach and Hemminger. Signed-off-by: dangshiwei <[email protected]> --- lib/eal/riscv/include/rte_prefetch.h | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/lib/eal/riscv/include/rte_prefetch.h b/lib/eal/riscv/include/rte_prefetch.h index 42146491ea..37b4787387 100644 --- a/lib/eal/riscv/include/rte_prefetch.h +++ b/lib/eal/riscv/include/rte_prefetch.h @@ -18,22 +18,24 @@ extern "C" { static inline void rte_prefetch0(const volatile void *p) { - RTE_SET_USED(p); + __builtin_prefetch((const void *)(uintptr_t)p); } static inline void rte_prefetch1(const volatile void *p) { - RTE_SET_USED(p); + /* Zicbop has no cache-level hints, fallback to rte_prefetch0 */ + rte_prefetch0(p); } static inline void rte_prefetch2(const volatile void *p) { - RTE_SET_USED(p); + /* Zicbop has no cache-level hints, fallback to rte_prefetch0 */ + rte_prefetch0(p); } static inline void rte_prefetch_non_temporal(const volatile void *p) { - /* non-temporal version not available, fallback to rte_prefetch0 */ + /* Zicbop has no non-temporal hint, fallback to rte_prefetch0 */ rte_prefetch0(p); } -- 2.43.0
