sfc: Avoid generating over-length MC_CMD_FLUSH_RX_QUEUES request
MCDI supports requests up to 252 bytes long, which is only enough to
pass 63 RX queue IDs to MC_CMD_FLUSH_RX_QUEUES. However a VF may have
up to 64 RX queues, and if we try to flush them all we will generate
an over-length request and BUG() in efx_mcdi_copyin(). Currently
all VF drivers limit themselves to 32 RX queues, so reducing the
limit to 63 does no harm.
Also add a BUILD_BUG_ON in efx_mcdi_flush_rxqs() so we remember to
deal with the same problem there if EFX_MAX_CHANNELS is increased.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
diff --git a/drivers/net/ethernet/sfc/mcdi.c b/drivers/net/ethernet/sfc/mcdi.c
index e855f4c..aea43cb 100644
--- a/drivers/net/ethernet/sfc/mcdi.c
+++ b/drivers/net/ethernet/sfc/mcdi.c
@@ -1195,6 +1195,9 @@
__le32 *qid;
int rc, count;
+ BUILD_BUG_ON(EFX_MAX_CHANNELS >
+ MC_CMD_FLUSH_RX_QUEUES_IN_QID_OFST_MAXNUM);
+
qid = kmalloc(EFX_MAX_CHANNELS * sizeof(*qid), GFP_KERNEL);
if (qid == NULL)
return -ENOMEM;