soc: fsl: dpio: read the consumer index from the cache inhibited area

Once we added support in the dpaa2-eth for driver level software TSO we
observed the following situation: if the EQCR CI (consumer index) is
read from the cache-enabled area we sometimes end up with a computed
value of available enqueue entries bigger than the size of the ring.

This eventually will lead to the multiple enqueue of the same FD which
will determine the same FD to end up on the Tx confirmation path and the
same skb being freed twice.

Just read the consumer index from the cache inhibited area so that we
avoid this situation.

Signed-off-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/soc/fsl/dpio/qbman-portal.c b/drivers/soc/fsl/dpio/qbman-portal.c
index 058b78fac5e39372e3c4432f0eda7bbdba554ece..0a3fb6c115f4af5948836fecb1bc1a29b6427219 100644 (file)
--- a/drivers/soc/fsl/dpio/qbman-portal.c
+++ b/drivers/soc/fsl/dpio/qbman-portal.c
@@ -743,8 +743,8 @@ int qbman_swp_enqueue_multiple_mem_back(struct qbman_swp *s,
        full_mask = s->eqcr.pi_ci_mask;
        if (!s->eqcr.available) {
                eqcr_ci = s->eqcr.ci;
-               p = s->addr_cena + QBMAN_CENA_SWP_EQCR_CI_MEMBACK;
-               s->eqcr.ci = *p & full_mask;
+               s->eqcr.ci = qbman_read_register(s, QBMAN_CINH_SWP_EQCR_CI);
+               s->eqcr.ci &= full_mask;
                s->eqcr.available = qm_cyc_diff(s->eqcr.pi_ring_size,
                                        eqcr_ci, s->eqcr.ci);
                if (!s->eqcr.available) {
@@ -887,8 +887,8 @@ int qbman_swp_enqueue_multiple_desc_mem_back(struct qbman_swp *s,
        full_mask = s->eqcr.pi_ci_mask;
        if (!s->eqcr.available) {
                eqcr_ci = s->eqcr.ci;
-               p = s->addr_cena + QBMAN_CENA_SWP_EQCR_CI_MEMBACK;
-               s->eqcr.ci = *p & full_mask;
+               s->eqcr.ci = qbman_read_register(s, QBMAN_CINH_SWP_EQCR_CI);
+               s->eqcr.ci &= full_mask;
                s->eqcr.available = qm_cyc_diff(s->eqcr.pi_ring_size,
                                        eqcr_ci, s->eqcr.ci);
                if (!s->eqcr.available)