From 711859cd0d076c7abc0c96ce637129a03280645f Mon Sep 17 00:00:00 2001 From: Phil Yang Date: Mon, 8 Oct 2018 17:11:45 +0800 Subject: [PATCH] kni: fix kernel FIFO synchronization Adding memory barrier to make sure the values being synced before updating fifo_write in kni_fifo_put and fifo_read in kni_fifo_get. Fixes: 3fc5ca2f6352 ("kni: initial import") Cc: stable@dpdk.org Signed-off-by: Phil Yang Reviewed-by: Honnappa Nagarahalli Reviewed-by: Gavin Hu Reviewed-by: Ferruh Yigit --- kernel/linux/kni/kni_fifo.h | 16 ++++++++++------ .../eal/include/exec-env/rte_kni_common.h | 1 + 2 files changed, 11 insertions(+), 6 deletions(-) diff --git a/kernel/linux/kni/kni_fifo.h b/kernel/linux/kni/kni_fifo.h index 9a4762de27..2cb3a4a7b8 100644 --- a/kernel/linux/kni/kni_fifo.h +++ b/kernel/linux/kni/kni_fifo.h @@ -16,7 +16,7 @@ kni_fifo_put(struct rte_kni_fifo *fifo, void **data, uint32_t num) { uint32_t i = 0; uint32_t fifo_write = fifo->write; - uint32_t fifo_read = fifo->read; + uint32_t fifo_read = smp_load_acquire(&fifo->read); uint32_t new_write = fifo_write; for (i = 0; i < num; i++) { @@ -27,7 +27,7 @@ kni_fifo_put(struct rte_kni_fifo *fifo, void **data, uint32_t num) fifo->buffer[fifo_write] = data[i]; fifo_write = new_write; } - fifo->write = fifo_write; + smp_store_release(&fifo->write, fifo_write); return i; } @@ -40,7 +40,7 @@ kni_fifo_get(struct rte_kni_fifo *fifo, void **data, uint32_t num) { uint32_t i = 0; uint32_t new_read = fifo->read; - uint32_t fifo_write = fifo->write; + uint32_t fifo_write = smp_load_acquire(&fifo->write); for (i = 0; i < num; i++) { if (new_read == fifo_write) @@ -49,7 +49,7 @@ kni_fifo_get(struct rte_kni_fifo *fifo, void **data, uint32_t num) data[i] = fifo->buffer[new_read]; new_read = (new_read + 1) & (fifo->len - 1); } - fifo->read = new_read; + smp_store_release(&fifo->read, new_read); return i; } @@ -60,7 +60,9 @@ kni_fifo_get(struct rte_kni_fifo *fifo, void **data, uint32_t num) static inline uint32_t kni_fifo_count(struct rte_kni_fifo *fifo) { - return (fifo->len + fifo->write - fifo->read) & (fifo->len - 1); + uint32_t fifo_write = smp_load_acquire(&fifo->write); + uint32_t fifo_read = smp_load_acquire(&fifo->read); + return (fifo->len + fifo_write - fifo_read) & (fifo->len - 1); } /** @@ -69,7 +71,9 @@ kni_fifo_count(struct rte_kni_fifo *fifo) static inline uint32_t kni_fifo_free_count(struct rte_kni_fifo *fifo) { - return (fifo->read - fifo->write - 1) & (fifo->len - 1); + uint32_t fifo_write = smp_load_acquire(&fifo->write); + uint32_t fifo_read = smp_load_acquire(&fifo->read); + return (fifo_read - fifo_write - 1) & (fifo->len - 1); } #endif /* _KNI_FIFO_H_ */ diff --git a/lib/librte_eal/linuxapp/eal/include/exec-env/rte_kni_common.h b/lib/librte_eal/linuxapp/eal/include/exec-env/rte_kni_common.h index cfa9448bd0..58e8533bec 100644 --- a/lib/librte_eal/linuxapp/eal/include/exec-env/rte_kni_common.h +++ b/lib/librte_eal/linuxapp/eal/include/exec-env/rte_kni_common.h @@ -8,6 +8,7 @@ #ifdef __KERNEL__ #include +#include #define RTE_STD_C11 #else #include -- 2.20.1