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authorPhil Yang <phil.yang@arm.com>2018-10-08 17:11:45 +0800
committerThomas Monjalon <thomas@monjalon.net>2018-10-26 18:10:14 +0200
commit711859cd0d076c7abc0c96ce637129a03280645f (patch)
tree53a07d7053a76ed64c4adccd451c949609e3c437 /kernel
parent0b05abe7bf9a46915bc1823753fc29c0a7b99ed1 (diff)
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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 <phil.yang@arm.com> Reviewed-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com> Reviewed-by: Gavin Hu <gavin.hu@arm.com> Reviewed-by: Ferruh Yigit <ferruh.yigit@intel.com>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/linux/kni/kni_fifo.h16
1 files changed, 10 insertions, 6 deletions
diff --git a/kernel/linux/kni/kni_fifo.h b/kernel/linux/kni/kni_fifo.h
index 9a4762d..2cb3a4a 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_ */