From a83ca0c280dd41dda576d6a8f15a8534a84b782c Mon Sep 17 00:00:00 2001 From: Marek Vasut Date: Mon, 23 Mar 2020 02:09:55 +0100 Subject: [PATCH] net: dwc_eth_qos: Invalidate RX packet DMA buffer This patch prevents an issue where the RX packet might have been accessed by the CPU, which now has cached data from the packet in the caches and possibly various write buffers, and these data may be evicted from the caches into the DRAM while the buffer is also written by the DMA. By invalidating the buffer after the CPU accessed it and before the DMA populates the buffer, it is assured that the buffer will not be corrupted. Reviewed-by: Patrick Delaunay Signed-off-by: Marek Vasut Cc: Joe Hershberger Cc: Patrice Chotard Cc: Patrick Delaunay Cc: Ramon Fried Cc: Stephen Warren --- drivers/net/dwc_eth_qos.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/net/dwc_eth_qos.c b/drivers/net/dwc_eth_qos.c index 2b37cc3..a195fe5 100644 --- a/drivers/net/dwc_eth_qos.c +++ b/drivers/net/dwc_eth_qos.c @@ -1476,6 +1476,9 @@ static int eqos_free_pkt(struct udevice *dev, uchar *packet, int length) } rx_desc = &(eqos->rx_descs[eqos->rx_desc_idx]); + + eqos->config->ops->eqos_inval_buffer(packet, length); + rx_desc->des0 = (u32)(ulong)packet; rx_desc->des1 = 0; rx_desc->des2 = 0; @@ -1538,6 +1541,9 @@ static int eqos_probe_resources_core(struct udevice *dev) } debug("%s: rx_pkt=%p\n", __func__, eqos->rx_pkt); + eqos->config->ops->eqos_inval_buffer(eqos->rx_dma_buf, + EQOS_MAX_PACKET_SIZE * EQOS_DESCRIPTORS_RX); + debug("%s: OK\n", __func__); return 0; -- 2.7.4