This is a note to let you know that I've just added the patch titled
net: axienet: add missing memory barriers
to the 5.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
net-axienet-add-missing-memory-barriers.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 95978df6fa328df619c15312e65ece469c2be2d2 Mon Sep 17 00:00:00 2001
From: Robert Hancock <robert.hancock@xxxxxxxxxx>
Date: Tue, 18 Jan 2022 15:41:27 -0600
Subject: net: axienet: add missing memory barriers
From: Robert Hancock <robert.hancock@xxxxxxxxxx>
commit 95978df6fa328df619c15312e65ece469c2be2d2 upstream.
This driver was missing some required memory barriers:
Use dma_rmb to ensure we see all updates to the descriptor after we see
that an entry has been completed.
Use wmb and rmb to avoid stale descriptor status between the TX path and
TX complete IRQ path.
Fixes: 8a3b7a252dca9 ("drivers/net/ethernet/xilinx: added Xilinx AXI Ethernet driver")
Signed-off-by: Robert Hancock <robert.hancock@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/net/ethernet/xilinx/xilinx_axienet_main.c | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)
--- a/drivers/net/ethernet/xilinx/xilinx_axienet_main.c
+++ b/drivers/net/ethernet/xilinx/xilinx_axienet_main.c
@@ -632,6 +632,8 @@ static int axienet_free_tx_chain(struct
if (nr_bds == -1 && !(status & XAXIDMA_BD_STS_COMPLETE_MASK))
break;
+ /* Ensure we see complete descriptor update */
+ dma_rmb();
phys = desc_get_phys_addr(lp, cur_p);
dma_unmap_single(ndev->dev.parent, phys,
(cur_p->cntrl & XAXIDMA_BD_CTRL_LENGTH_MASK),
@@ -645,8 +647,10 @@ static int axienet_free_tx_chain(struct
cur_p->app1 = 0;
cur_p->app2 = 0;
cur_p->app4 = 0;
- cur_p->status = 0;
cur_p->skb = NULL;
+ /* ensure our transmit path and device don't prematurely see status cleared */
+ wmb();
+ cur_p->status = 0;
if (sizep)
*sizep += status & XAXIDMA_BD_STS_ACTUAL_LEN_MASK;
@@ -704,6 +708,9 @@ static inline int axienet_check_tx_bd_sp
int num_frag)
{
struct axidma_bd *cur_p;
+
+ /* Ensure we see all descriptor updates from device or TX IRQ path */
+ rmb();
cur_p = &lp->tx_bd_v[(lp->tx_bd_tail + num_frag) % lp->tx_bd_num];
if (cur_p->status & XAXIDMA_BD_STS_ALL_MASK)
return NETDEV_TX_BUSY;
@@ -843,6 +850,8 @@ static void axienet_recv(struct net_devi
tail_p = lp->rx_bd_p + sizeof(*lp->rx_bd_v) * lp->rx_bd_ci;
+ /* Ensure we see complete descriptor update */
+ dma_rmb();
phys = desc_get_phys_addr(lp, cur_p);
dma_unmap_single(ndev->dev.parent, phys, lp->max_frm_size,
DMA_FROM_DEVICE);
Patches currently in stable-queue which might be from robert.hancock@xxxxxxxxxx are
queue-5.10/net-axienet-wait-for-phyrstcmplt-after-core-reset.patch
queue-5.10/net-axienet-add-missing-memory-barriers.patch
queue-5.10/clk-si5341-fix-clock-hw-provider-cleanup.patch
queue-5.10/net-axienet-increase-default-tx-ring-size-to-128.patch
queue-5.10/net-axienet-fix-tx-ring-slot-available-check.patch
queue-5.10/net-axienet-fix-for-tx-busy-handling.patch
queue-5.10/net-axienet-limit-minimum-tx-ring-size.patch
queue-5.10/net-axienet-reset-core-on-initialization-prior-to-mdio-access.patch
queue-5.10/net-axienet-fix-number-of-tx-ring-slots-for-available-check.patch
queue-5.10/net-axienet-increase-reset-timeout.patch
