From af3826db74d184bc9c2c9d3ff34548e5f317a6f3 Mon Sep 17 00:00:00 2001 From: Geetha sowjanya Date: Tue, 28 Sep 2021 11:25:26 +0530 Subject: octeontx2-pf: Use hardware register for CQE count Current driver uses software CQ head pointer to poll on CQE header in memory to determine if CQE is valid. Software needs to make sure, that the reads of the CQE do not get re-ordered so much that it ends up with an inconsistent view of the CQE. To ensure that DMB barrier after read to first CQE cacheline and before reading of the rest of the CQE is needed. But having barrier for every CQE read will impact the performance, instead use hardware CQ head and tail pointers to find the valid number of CQEs. Signed-off-by: Geetha sowjanya Signed-off-by: Sunil Kovvuri Goutham Signed-off-by: David S. Miller --- include/linux/soc/marvell/octeontx2/asm.h | 14 ++++++++++++++ 1 file changed, 14 insertions(+) (limited to 'include/linux/soc') diff --git a/include/linux/soc/marvell/octeontx2/asm.h b/include/linux/soc/marvell/octeontx2/asm.h index fa1d6af0164e..0f79fd7f81a1 100644 --- a/include/linux/soc/marvell/octeontx2/asm.h +++ b/include/linux/soc/marvell/octeontx2/asm.h @@ -34,9 +34,23 @@ : [rf] "+r"(val) \ : [rs] "r"(addr)); \ }) + +static inline u64 otx2_atomic64_fetch_add(u64 incr, u64 *ptr) +{ + u64 result; + + asm volatile (".cpu generic+lse\n" + "ldadda %x[i], %x[r], [%[b]]" + : [r] "=r" (result), "+m" (*ptr) + : [i] "r" (incr), [b] "r" (ptr) + : "memory"); + return result; +} + #else #define otx2_lmt_flush(ioaddr) ({ 0; }) #define cn10k_lmt_flush(val, addr) ({ addr = val; }) +#define otx2_atomic64_fetch_add(incr, ptr) ({ incr; }) #endif #endif /* __SOC_OTX2_ASM_H */ -- cgit v1.2.3